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| United States Patent Application |
20110206691
|
| Kind Code
|
A1
|
|
Mosse; Yael P.
;   et al.
|
August 25, 2011
|
Methods and Compositions for Treating Neuroblastoma
Abstract
Methods and compositions for treating neuroblastoma are disclosed.
| Inventors: |
Mosse; Yael P.; (Wynnewood, PA)
; Carpenter; Erica L.; (Wyndmoor, PA)
|
| Serial No.:
|
072090 |
| Series Code:
|
13
|
| Filed:
|
March 25, 2011 |
| Current U.S. Class: |
424/158.1 |
| Class at Publication: |
424/158.1 |
| International Class: |
A61K 39/395 20060101 A61K039/395; A61P 35/00 20060101 A61P035/00 |
Claims
1. A method for inhibiting neuroblastoma in a subject comprising the
administration of at least one composition comprising at least one ALK
antibody and at least one pharmaceutically acceptable carrier.
2. The method of claim 1, wherein said ALK antibody is immunologically
specific for the extracellular domain of ALK.
3. The method of claim 1, wherein said neuroblastoma is resistant to at
least one ALK inhibitor.
4. The method of claim 1, wherein said neuroblastoma is resistant to
crizotinib.
5. The method of claim 1, further comprising the administration of at
least one composition comprising at least one ALK inhibitor and at least
one pharmaceutically acceptable carrier.
6. The method of claim 5, wherein said ALK inhibitor is a small molecule
inhibitor.
7. The method of claim 6, wherein said ALK inhibitor is crizotinib.
8. A kit comprising a first composition comprising at least one ALK
antibody and at least one pharmaceutically acceptable carrier and a
second composition comprising at least one ALK inhibitor and at least one
pharmaceutically acceptable carrier.
Description
[0001] This application is a continuation-in-part of 12/853,834, filed on
Aug. 10, 2010, which is a continuation-in-part of PCT/US2009/034288,
filed on Feb. 17, 2009, which claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Patent Application No. 61/029,212, filed
on Feb. 15, 2008 and to U.S. Provisional Patent Application No.
61/123,775, filed on Apr. 11, 2008. The foregoing applications are
incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to the fields of neuroblastoma. More
specifically, the invention provides compositions and methods for the
identification, diagnosis, and treatment of neuroblastoma.
BACKGROUND OF THE INVENTION
[0003] Several publications and patent documents are cited throughout the
specification in order to describe the state of the art to which this
invention pertains.
[0004] Each of these citations is incorporated herein by reference as
though set forth in full.
[0005] Neuroblastoma is a cancer of early childhood that arises from the
developing autonomic nervous system. It is the most common malignancy
diagnosed in the first year of life and shows a wide range of clinical
phenotypes with some patients having tumors that regress spontaneously,
whereas the majority of patients have aggressive metastatic disease
(Maris et al. (2007) Lancet 369:2106-20). These latter neuroblastoma
cases have survival probabilities of less then 40% despite intensive
chemoradiotherapy, and the disease continues to account for 15% of
childhood cancer mortality (Maris et al. (2007) Lancet, 369:2106-20;
Matthay et al. (1999) N. Eng. J. Med., 341:1165-73). Tumors from patients
with an aggressive phenotype often show amplification of the MYCN
oncogene (Schwab et al. (1984) Nature, 308:288-91), and/or deletions of
chromosome arms 1p and 11q (Attiyeh et al. (2005) N. Engl. J. Med.,
353:2243-53). However, because MYCN is so aberrantly dysregulated, and no
putative tumor suppressor gene at 1p and 11 q has been shown to harbor
inactivating mutations in more than a small percentage of cases, no
tractable molecular target approaches currently exist for this disease.
[0006] Like most human cancers, a small subset of neuroblastoma cases are
inherited in an autosomal dominant manner (Knudson et al. (1972) Amer. J.
Hum. Genet., 24:514-522; Kushner et al. (1986) Cancer, 57:1887-1893;
Maris et al. (1997) Eur. J. Cancer, 33:1923-1928). A family history of
the disease is found in about 1-2% of newly diagnosed cases, with a
standardized incidence ratio of 9.7 for siblings of index cases (Friedman
et al. (2005) Cancer Epidemiol. Biomarkers Prev., 14:1922-7).
Neuroblastoma pedigrees show striking heterogeneity in the type of tumors
that arise, with both benign and malignant forms occurring in the same
family (Maris et al. in Neuroblastoma (eds. Cheung et al.) 21-26
(Springer, Berlin, Heidelberg, New York, 2005). Familial neuroblastoma
patients differ from those with sporadic disease in that they are
diagnosed at an earlier age and/or with multiple primary tumors, clinical
characteristics that are hallmarks of cancer predisposition syndromes.
Because of the lethality of the condition prior to reproductive age,
previous genetic linkage scans have been underpowered and results
difficult to replicate (Longo et al. (2007) Hum. Hered., 63:205-11; Maris
et al. (2002) Cancer Res., 62:6651-6658; Perri et al. (2002) Oncogene
21:8356-60). Remarkably, neuroblastoma can occur with a spectrum of
disorders related to abnormal development of neural crest derived tissues
including central congenital hypoventilation syndrome and Hirschsprung
disease. Missense or nonsense mutations in PHOX2B (paired-like homeobox
2B), a homeobox gene that is a master regulator of normal autonomic
nervous system development, were recently shown to predispose to this
rare field defect of the sympathicoadrenal lineage tissues (Amiel et al.
(2003) Nat. Genet., 33:459-61; Mosse et al. (2004) Am. J. Hum. Genet.,
75:727-30; Trochet et al. Am. J. Hum. Genet., 74:761-4). However, PHOX2B
mutations explain only a small subset of hereditary neuroblastoma, are
almost exclusive to cases with associated disorders of neural
crest-derived tissues, and are not somatically acquired in tumors (Raabe
et al. (2008) Oncogene, 27:469-76; van Limpt et al. (2004) Oncogene,
23:9280-8), leaving the genetic etiology for the majority of familial
neuroblastoma cases unknown.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention, methods of detecting an
increased risk for neuroblastoma in a subject are provided. Methods of
diagnosing and/or prognosing neuroblastoma in a subject are also
provided. In a particular embodiment, the method comprises obtaining a
biological sample from the subject and determining whether the anaplastic
lymphoma kinase (ALK) gene and/or protein is altered in the biological
sample, wherein the presence of the alteration of the ALK gene and/or
protein is indicative of neuroblastoma in the subject and/or indicative
of an increased risk of metastasis and/or death. In another embodiment,
the alteration in the ALK gene is selected from the group consisting of
an amplification the ALK copy number, presence of at least one mutation
which increases ALK activity, increased levels of ALK phosphorylation,
and a translocation involving ALK which increases ALK activity. In a
particular embodiment, the ALK mutations which increase ALK activity are
in the tyrosine kinase domain.
[0008] In accordance with another aspect of the instant invention, methods
for treating, inhibiting, and/or preventing (e.g., inhibiting the onset)
neuroblastoma in a patient are provided. In a particular embodiment, the
methods comprise the administration of at least one composition
comprising at least one ALK inhibitor and, optionally, at least one
chemotherapeutic agent. In another embodiment, the methods comprise the
administration of at least one composition comprising at least one ALK
antibody and, optionally, at least one ALK inhibitor, at least one other
chemotherapeutic agent or therapy, and/or at least one GD2 antibody. In
another embodiment, the patient is screened prior to administration of
the composition in order to determine which ALK inhibitor is most
effective against the particular neuroblastoma of the patient.
[0009] In yet another aspect of the invention, methods of determining
whether a compound is effective for treating neuroblastoma are provided.
In one embodiment, the method comprises contacting cells comprising
mutations in ALK or an amplification of ALK encoding nucleic acid
molecules, with at least one compound; and determining the ALK activity
or cell viability or proliferation, wherein a reduction in ALK activity
or cell viability or proliferation indicates the compound is therapeutic
for treating a neuroblastoma which comprises the mutation or
amplification.
[0010] In accordance with another aspect of the instant invention,
microarrays comprising oligonucleotide probes which specifically
hybridize with at least one ALK mutant are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a graph of the eight neuroblastoma pedigrees with ALK
mutations. All family members with DNA available for genotyping indicated
with either wild type (wt) for ALK, or with mutation in the ALK tyrosine
kinase domain (R1192P, R1275Q, G1128A). Individuals affected by
neuroblastoma indicated by filled symbol.
[0012] FIG. 2A provides a schematic diagram indicating protein structure
of ALK, with mutations discovered in constitutional DNAs of familial
cases (germline) and primary tumors from sporadic cases (somatic)
indicated. All but one sequence alteration mapped to the tyrosine kinase
domain (D1091N was just N-terminal and is not indicated here). Of the
three germline mutations discovered, only the R1275Q was found in the
tumor DNA samples. Conversely, the 11250T mutation discovered in the
tumor set was also present in the matched germline DNA of that patient,
while all of the other mutations studied here were somatically acquired.
FIG. 2B provides a homology model of wild-type ALK with each major
subdomain indicated
[0013] (Torkamani et al. (2007) Bioinformatics, 23:2918-25; Torkamani et
al. (2008) Cancer Res., 68:1675-82). FIG. 2C shows ALK mutations mapped
onto homology model (orientation different to show all mutations) with
shades indicating subdomain in which the mutation resides (e.g. the
R1275Q mutation falls within the activation segment).
[0014] FIGS. 3A-3E provide representative ALK copy number alterations in
five neuroblastoma primary tumors. Hybridization intensity reflecting
copy number for all SNPs along chromosome 2p in three primary tumors from
patients with sporadically occurring disease is shown, represented on a
logarithmic scale. MYCN amplification is present in all tumors. FIG. 3A
is a regional gain (trisomy) of chromosome 2p, including the ALK locus.
FIG. 3B is the focal gain of the ALK locus. FIG. 3C is the focal
amplification of the ALK locus. FIGS. 3D and 3E are a complex
rearrangement of the 2p locus, showing various focal amplicons, including
MYCN and ALK. FIG. 4 demonstrates that ALK is highly expressed and the
kinase is phosphorylated in neuroblastoma cell lines harboring activating
mutations. FIG. 4A provides a graph showing the relative ALK expression
of neuroblastoma cell lines and fetal brain determined using the 2-AACt
method (Livak et al. (2001) Methods 25:402-8.). Statistical significance
was determined by unpaired T-test. FIG. 4B provides immunoblots showing
differential ALK expression in neuroblastoma cell lines with
phosphorylation of the tyrosine 1604 codon restricted to cell lines with
mutations (the wild-type lines NBEC I and NB1771 show faint
phosphostaining).
[0015] FIGS. 5A-5L demonstrate that ALK knockdown results in growth
inhibition of ALK mutated or amplified neuroblastoma cell lines. FIGS.
5A-5J show cellular growth for ten neuroblastoma cell lines that were
transfected with siRNAs against ALK or GAPDH (two negative controls and
one positive control not shown for clarity). The x-axis is time in hours
after transfection, the y-axis is percent growth normalized to the siRNA
against GAPDH. FIG. 5K provides a summary of percentage growth inhibition
with ALK siRNA knockdown by ALK mutational and allelic status. FIG. 5L
provides an immunoblot showing a time course of ALK protein knockdown in
the cell lines KELLY and SKNDZ.
[0016] FIG. 6A is a graph of a dose response curve and FIG. 6B is a graph
of the % growth inhibition with PF066 at 333 nM.
[0017] FIG. 7 shows the expression of pALK, pAKT, pSTAT3, and pMAPK3.
[0018] FIG. 8A provides the IC.sub.50 of various drugs on the
neuroblastoma cell line KELLY (F1147L). FIG. 8B provides graphs of tumor
volume after weeks of administration of PF'066.
[0019] FIG. 9A provides an amino acid sequence of ALK (SEQ ID NO: 5). FIG.
9B provides a nucleotide sequence of ALK (SEQ ID NO: 6).
[0020] FIGS. 10A and 10B demonstrate that a gain of ALK locus correlates
with increased mRNA expression. The significance of recurrent regional
gain/amplification on the p-arm of chromosome 2 for 591 tumors was
assessed using the Significance Testing for Aberrant Copy (STAC)
algorithm (FIG. 10A). Significance is plotted as -log10 (P-value) in 1-Mb
windows along the p-arm of chromosome 2. Flat line marks threshold for
statistical significance (adjusted P<=0.05). Frequency statistic (dark
line) reveals significant recurrent focal amplification of both MYCN
(P<0.001) and ALK (P=0.026). Footprint statistic (light line) reveals
large 41-Mb region of recurrent low-level gain encompassing both MYCN and
ALK (P=0.004). FIG. 10B shows that ALK mRNA expression levels are
significantly increased in tumors harboring either focal high level
amplification (P<0.0001) or low-level regional gain (P<0.0001) when
compared to tumors with no regional gain of ALK. Box and whisker plot of
relative ALK mRNA expression is shown; lower and upper whiskers represent
5th and 95th percentile respectively.
[0021] FIGS. 11A and 11B show mRNA expression and constitutive
phosphorylation of ALK in RPE1 cells expressing activating ALK mutations.
FIG. 11A provides the relative ALK expression of 2 neuroblastoma cell
lines (NB1 and NB 1643), HTERT-RPE1 cell lines transfected with NPM-ALK
and 4 ALK mutants, wild-type ALK, empty vector, and native cells,
determined using the 2.sup.-.DELTA..DELTA.C.sub.T method (Livak et al.
(2001) Methods 25:402-408). FIG. 11B provides immunoblots showing
differential pALK expression at I minute and 5 minutes in the various
HTERT-RPE1 cells transfected with NPM-ALK, 4 ALK mutants, wild-type ALK,
empty vector and native RPE1 cells.
[0022] FIG. 12 shows the varying sensitivity of different ALK aberrations
to ALK inhibition. Proliferation of neuroblastoma cell lines was measured
over 72 hours of incubation with PF2341066, 333 nM in DMSO using the
RT-CES system. Cell lines harboring ALK amplification or mutations were
significantly more sensitive than cell lines with normal copy number,
wild type ALK (p=0.0004). In addition, cell lines harboring the R1275Q
mutation were significantly more sensitive than cell lines harboring
F1174L mutations (P =0.041). Inhibition of growth %=100*(cell index
vehicle-cell index treatment)/cell index control.
[0023] FIGS. 13A-13C show that in vitro growth inhibition is associated
with abrogation of phosphorylation of ALK and downstream signaling
proteins. Abrogation of phospho-ALK correlates to the dose where in vitro
proliferation is first inhibited for all three-cell lines. NB I (wild
type amplified; FIG. 13A) and NB 1643 (R1275Q; FIG. 13B) have similar
growth inhibition. NB1 shows substantial abrogation of phosphorylation of
STAT3, AKT and ERK but NB 1643 does not, indicating NB1643 may signal
through mutation specific pathways. SHSY5Y (FIG. 13C) shows inhibition of
in vitro proliferation and abrogation of phospho-ALK at higher doses than
NB1 and NB 1643 indicating that PF-02341066 is less able to inhibit ALK
signaling for this mutation.
[0024] FIGS. 14A-14E show PF-2341066 activity in vivo is associated with
ALK mutations or ALK protein activation. CB17 scid mice were randomized
to 4 weeks of PF-2341066 100mg/kg/day via oral gavage (straight line), or
vehicle (hashed line) and enrolled when xenograft volumes were 0.2-0.3
cm.sup.3. Tumor volume is displayed as mean.+-.S.E.M. The study end
points for survival analysis were tumor volume.gtoreq.1.5 cm.sup.3 or
treatment related death NB1643 (R1275Q; FIG. 14A) xenografts treated with
PF-2341066 regressed completely by day 15 (P<0.0001). The treatment
arm of SHSY5Y (F1174L; FIG. 14B) showed significant tumor growth delay
(P<0.0001) and prolonged survival by 7.7 days (P<0.0001). NBSD
(F1174L; FIG. 14C) which were more resistant than SHSY5Y in vitro, did
not show significant tumor growth delay (P=0.3), but did prolong survival
by 3.7 days (P=0.04). Two xenograft lines were treated with WT ALK.
NBEBc1 (WT; FIG. 14D) which has weak phospho-ALK staining showed
significant delayed tumor progression (P<0.0001), and prolongation of
survival by 5.1 days (p=0.0019). By contrast, SKNAS (WT; FIG. 14E) which
has low ALK expression and no detectable pALK showed neither a delay in
tumor growth (P=0.87) or prolongation of survival (P=0.70). FIGS. 15A-15D
show that homology modeling of ALK mutations predicts differential
sensitivity to pharmacologic inhibition. FIG. 15A provides a model of
PF-02341066 binding to ALK. A homology model of the PF-02341066 binding
to ALK was derived from the crystal structure of PF-02341066 bound to the
kinase domain of c-Met (PDB entry=2WGJ). Only selected side chain
residues are shown. FIG. 15B provides a model of the interaction between
PF-02341066 and the activation loop of ALK. Van der Waals atomic surfaces
are depicted for PF-02341066 and for residues 1270-1278 of the ALK model.
FIG. 15C provides a model of R1275Q mutation in ALK. Modeling predicts
that the side chain of R1275 is on the protein surface and that a R1275Q
substitution is unlikely to result in a large destabilization of
PF-02341066 binding to ALK. FIG. 15D shows that modeling predicts loss of
stabilizing protein interactions in F1174L ALK. Direct interactions
between F 1174, F 1245, and F1271 are predicted to stabilize the protein
conformation necessary for tight binding of PF-02341066. Substitution of
leucine at position 1174 is predicted to result in a significant decrease
in attractive interactions within this hydrophobic core.
[0025] FIG. 16 is a graph of normalized cell index of SH-Sy5Y (F1174L)
cells treated with vehicle, PF-1066, mAb30+49, or PF-1066 and mAb30+49.
[0026] FIG. 17A provides a graph showing ALK expression in 229
neuroblastoma patient tumors analyzed by Affymetrix Human Exon Array and
normalized using quantile normalization (HRA=High risk MYCN amplified
neuroblastoma, n=64; HRN=High risk MYCN non-amplified neuroblastoma,
n=141; LR=Low risk, n=24). FIG. 17B provides representative images for
immunohistochemical staining of ALK in neuroblastoma patient tumors. ALK
staining was positive overall in 109 of 126 (86.5%) samples analyzed. 17
samples showed no positive staining (upper left panel); 35 showed
weak/Grade 1 staining (upper right panel); 55 showed moderate/Grade 2
staining (lower left panel); and 19 showed strong/Grade 3 staining (lower
right panel). FIG. 17C provides box plots showing 10th percentile, 90th
percentile, and mean ALK score by immunohistochemistry for INSS stage
(top panel) and MYCN status (bottom panel; A=MYCN amplified, N=MYCN
non-amplified). **, p<0.01; *, p<0.05. FIG. 17D provides a
representative flow cytometry analysis of NB1 cells with an ALK antibody
to assess cell-surface expression levels. Mean fluorescence intensity
(MFI) is shown for ALK staining (black line) and an isotype control (grey
line). FIG. 17E provides a graph showing the comparison of flow cytometry
results for several neuroblastoma cell lines. Grey bars show flow
cytometry results for ALK cell surface staining. White bars represent an
ALK mRNA expression `index` (relative expression) measured as ALK levels
relative to HPRT1. FIG. 17F provides immunofluorescence staining of
neuroblastoma cells lines with anti-ALK demonstrates cell surface ALK
expression for NB1 (left panel) and SY5Y cells (right panel).
[0027] FIG. 18A provides a graph showing ALK antibody-induced growth
inhibition and ADCC of neuroblastoma cells. To measure growth inhibition
upon antibody exposure, cell lines were plated in 96-well plates and
treated with anti-ALK (mAb30 plus mAb49) or a negative control murine
IgGl. Cell growth was monitored by Real Time Cell Electronic Sensing
(RT-CES) impedance measurement. Growth inhibition of SY5Y cells treated
with indicated amounts of anti-ALK as compared to control Ig. FIG. 18B
shows the indicated cell lines were treated with 10 .mu.g/ml ALK antibody
and growth inhibition was measured after 144 hours. FIG. 18C provides a
graph showing the effect of anti-ALK antibody on RPE1 cell growth.
ALK-negative RPE-1 cells were plated in 96-well plates and treated with
either 10 .mu.g/ml anti-ALK antibody or murine immunoglobulin . Shown is
cell growth for each condition as measured by RT-CES. In FIG. 18D, ADCC
was measured using an in vitro assay in which normal donor peripheral
blood lymphocytes (PBL), pre-incubated overnight with IL-2, were
co-incubated for four hours with neuroblastoma cells in the presence
(black line) or absence (grey line) of 1 .mu.g/ml ALK antibody. Shown are
% cytotoxicity at the indicated effector:target ratios when NB1 cells
(left panel), SY5Y cells (middle panel), or ALK-negative SKNAS cells
(right panel) were used as targets.
[0028] FIG. 19A shows the effect of crizotinib on cell surface ALK
expression. SY5Y cells were incubated with crizotinib or vehicle,
harvested and stained for cell surface ALK with mAb14. ViaProbe viability
stain was used to exclude non-viable cells. A representative flow
cytometry result is shown for SY5Y cells incubated for 72 hours with
either vehicle (medium gray line) or 1000 nM crizotinib (black line). The
single-peaked light grey line represents the isotype control. FIG. 19B
shows the concentration dependence of the percent change in cell surface
ALK, as measured by Mean Fluorescence Intensity (MFI), for cells
incubated for 72 hours with varying concentrations of crizotinib as
compared to vehicle. FIG. 19C provides a time course of percentage change
in cell surface ALK levels (over that seen for vehicle treatment) when
cells were incubated with 1000 nM crizotinib. FIG. 19D shows a comparison
of ALK antibodies for flow cytometry. SY5Y cells were treated with 1000
nM crizotinib or vehicle, harvested 72 hours later, and stained for flow
cytometry. Shown is the percent increase in ALK MFI for crizotinib versus
vehicle treated cells using either the mAbl4 or mAB46 anti-ALK
antibodies.
[0029] FIG. 20 shows dual antibody/TKI targeting of ALK. SY5Y cells were
treated with either 333 nM crizotinib or 10 .mu.g/ml anti-ALK antibody
(mAb30+mAb49), or both. As negative control, cells were treated with
equal volumes of DMSO and 10 .mu.g/ml IgG1. FIG. 20A shows cell growth
monitored by RT-CES, revealing clear growth inhibition by the
crizotinib/mAb combination. FIG. 20B provides an immunoblot analysis of
native ALK protein levels (upper panel) and phospho-ALK (middle panel).
.beta.-actin levels are shown as a loading control (lower panel). FIG.
20C shows the effect of crizotinib pre-treatment on anti-ALK antibody
mediated ADCC. SY5Y cells were pre-incubated in the presence of
crizotinib or vehicle for 48 hours, harvested, and then used as target
cells in the in vitro ADCC assay. **, p<0.01; *, p<0.05.
[0030] FIG. 21 shows the effects of an antagonist ALK antibody on
crizotinib dose-response curve. SY5Y cells were treated with crizotinib
at the indicated doses either alone or in combination with 10 .mu.g/ml
(total) ALK antibody mAb30 and mAb49. Cell growth was measured at day 7
using RT-CES. FIG. 21A shows the comparison of growth inhibition for
monotherapy versus dual ALK targeting: white bars represent crizotinib
alone, grey bars crizotinib treatment in the presence of 10 .mu.g/ml
anti-ALK. **, p<0.01; *, p<0.05. In FIG. 21B, IC.sub.50 was
calculated over a range of 10 doses of crizotinib alone (circles) or
crizotinib plus 10 .mu.g/ml anti-ALK (squares), yielding IC.sub.50 values
of 3018 nM and 1745 nM respectively.
[0031] FIG. 22 shows the cell cycle analysis of inhibitor-treated cells.
SY5Y cells were treated with 1000 nM crizotinib, 10 .mu.g/ml antibody,
both, or vehicle/IgG1, and were then harvested, fixed, stained with
propidium iodide, and analyzed by flow cytometry. FIG. 22A provides
representative histograms showing proportion of cells in sub
G0/apoptosis, G0/G1, and G2/mitosis. FIG. 22B provides the quantification
of flow cytometry results. ** p<0.01; * p<0.05.
DETAILED DESCRIPTION OF THE INVENTION
[0032] As stated hereinabove, neuroblastoma is a childhood cancer that can
be inherited, but the genetic etiology was largely unknown. Here it is
shown that germline mutations in the anaplastic lymphoma kinase gene
(ALK) explain the majority of hereditary neuroblastomas and that
activating mutations can also be somatically acquired. A significant
linkage signal at chromosome 2p24-23 was first identified using a
whole-genome scan in neuroblastoma pedigrees. Resequencing of regional
candidate genes identified three separate germline missense mutations in
the tyrosine kinase domain of ALK that segregated with the disease in
eight separate families. Resequencing in 194 high-risk neuroblastoma
samples showed somatically (only in tumor cells) acquired mutations
within the tyrosine kinase domain in 12.4%.
[0033] Nine of the ten mutations map to critical regions of the kinase
domain and were predicted to be oncogenic drivers with high probability.
Mutations resulted in constitutive phosphorylation, and targeted
knockdown of ALK mRNA resulted in profound growth inhibition of all cell
lines harboring mutant or amplified ALK, as well as 2 of 6 wild type for
ALK. These results demonstrate that heritable mutations of ALK are the
major cause of familial neuroblastoma, and that germline or acquired
activation of this cell surface kinase is a tractable therapeutic target
for this lethal pediatric malignancy
[0034] It has been predicted that neuroblastoma, like the analogous
embryonal cancer retinoblastoma, would follow a two-hit model explaining
hereditary and sporadic cases (Knudson et al. (1972) Amer. J. Hum.
Genet., 24:514-522). This model has proven to be correct for the majority
of childhood and adult hereditary cancers and the susceptibility genes
are typically tumor suppressors where the two hits are sequential
inactivation of both alleles. Discovery of heritable mutations in
oncogenes as the etiology of multiple endocrine neoplasia 1 cancers
(RET), papillary renal carcinoma (MET) and gastrointestinal stromal
tumors (KIT) challenged this paradigm, but it is now clear that
somatically acquired duplication or amplification of the mutant allele
provides the second hit (Vogelstein et al. (2004) Nat. Med., 10:789-99).
It is shown herein that heritable mutations in ALK are the cause of the
majority of hereditary neuroblastoma cases, providing the first example
of a pediatric cancer arising due to mutations in an oncogene. Taken
together with the recent report that common variations at chromosome band
6p22 predispose to the development of sporadic neuroblastoma (Maris et
al. (2008) N. Engl. J. Med., 358:2585-93), the genetic etiology of this
disease is now being defined. The discovery of highly penetrant heritable
ALK mutations as the cause of hereditary neuroblastoma are of immediate
relevance to patients with a family history as screening with noninvasive
techniques such as ultrasonography and measurement of urinary
catecholamine metabolites should likely be implemented for unaffected
children carrying an ALK mutation. ALK is an orphan tyrosine kinase
transmembrane receptor with homology to neurotrophin receptors and the
MET oncogene. Expression is restricted to the developing nervous system
with a postulated role in participating in the regulation of neuronal
differentiation (Iwahara et al. (1997) Oncogene, 14:439-49). It is now
clear that many human cancers activate ALK signaling by creating unique
oncogenic fusions of ALK with a variety of partners through chromosomal
translocation events (Chiarle et al. (2008) Nat. Rev. Cancer, 8:11-23).
Previous work had shown that a substantial percentage of human-derived
neuroblastoma cell lines express ALK transcripts and ALK protein (Lamant
et al. (2000) Am. J. Pathol., 156:1711-21), but no definitive role for
this oncogene had been proven (Osajima-Hakomori et al. (2005) Am. J.
Pathol., 167:213-22; Motegi et al. (2004) J. Cell Sci., 117:3319-29;
Miyake et al. (2002) Oncogene, 21:5823-34; Dirks et al. (2002) Int. J.
Cancer, 100:49-56). ALK has recently been identified as a molecular
target in neuroblastoma through a screen of human cancer cell lines with
pharmacologic antagonists of the ALK kinase domain (McDermott et al.
(2008) Cancer Res., 68:3389-95). The data herein provides the first
evidence for oncogenic activation of ALK via mutation of the kinase
domain, and these data provide the genetic basis for the observation of
sensitization to ALK kinase inhibition. In addition, the discoveries in
neuroblastoma may lead to future resequencing efforts in other
malignancies, especially those where oncogenic fusion proteins have
recently been discovered. The data presented here clearly establish ALK
as critical neuroblastoma oncogene and should increase efforts to
identify the ligand for this receptor and understand if ALK-mediated
signaling can be activated by mechanisms other than direct mutation
and/or amplification of ALK alleles. Finally, receptor tyrosine kinases
provide tractable targets for pharmacologic inhibition, and allows for
therapeutic strategies aimed at inhibiting ALK-mediated signaling.
[0035] In accordance with the instant invention, methods of identifying,
determining an increased risk for, diagnosing, and/or prognosing a cancer
in a patient are provided, wherein the method comprises determining the
level/activity of ALK. In a particular embodiment, the cancer is
neuroblastoma. In another embodiment, the cancer has been characterized
as having an ALK translocation (e.g., an ALK translocation wherein the
resultant ALK fusion protein is constitutively active). Such cancers
include, without limitation, lymphomas, non-Hodgkin's lymphoma, anaplasic
large cell lymphoma, inflammatory myofibroblastic tumors, and
non-small-cell lung cancer. The methods may further comprise obtaining a
biological sample from the subject. In a particular embodiment, the
biological sample is tumor tissue or blood.
[0036] In one embodiment, the method comprises determining the presence of
at least one mutation in ALK, particularly one which leads to increased
activity of ALK (e.g., increased kinase activity). According to one
embodiment, the mutation is within the kinase domain. In another
embodiment, at least one amino acid at position P36, P157, V198, G640,
L684, G718, D993, L1204, 11170, A1200, L1204, F1245, G1128, R1192, R1275,
D1091, M1166, 11171, F1174, F1245, 11250, and those set forth in Tables
2A and 2B (e.g., TI 151, L1196, R259, M770, E1407, E1433, R1464, G1494,
A1553) is altered (mutated). In another embodiment, at least one amino
acid at position G1128, R1192, R1275, D1091, M1166,11171, F1174, F1245,
and 11250 is altered (mutated). In still another embodiment, at least one
amino acid at position G1128, R1192, L1204, 11250, R1275, and those set
forth in Tables 2A and 2B (e.g., P36, V198, R259, G640, D993, E1407, and
A1553); particularly, at least one amino acid at position GI 128, R1192,
and R1275 is altered (mutated; particularly those set forth below) when
the germline is examined (e.g., when the biological sample is not tumor
tissue). In one embodiment, at least one amino acid at position P36,
P157, V198, G640, L684, G718, D993, L1204, 11170, A1200, L1204, G1128,
R1192, R1275, D1091, M1166, 11171, F1174, F1245, 11250 and those set
forth in Tables 2A and 2B (e.g., T1151, 11170, L1196, R259, M770, E1407,
E1433, R1464, G1494, A1553); particularly, at least one amino acid at
position P36, P157, V 198, G640, L684, G718, G718, D993, L1204, 11170,
A1200, L1204, F1245, R1275, D1091, M1166, 11171, F1174, F1245, and 11250;
particularly, at least one amino acid at position R1275, D1091, M1166,
11171, F1174, F1245, and 11250 is altered (mutated; particularly those
set forth below) when somatic mutations are examined (e.g., when the
biological sample is tumor tissue/cells). In another embodiment, the
mutation may be a nonconservative amino acid substitution. In still
another embodiment, the ALK comprises at least one mutation selected from
the group consisting of P36S, P157S, V198M, G640R, L684M, G718F, G718S,
D993G, L1204F, I117OS, A1200V, L1204F, F1245I, G1128A, R1192P, R1275Q,
D1091N, M1166R, I1171N, F1174I, F1174L, F1245C, F1245V, I1250T, and those
set forth in Tables 2A and 2B (e.g., T1151M, I1170S, F1174C, L1196M,
F1245I, R259H, M770I, E1407K, E1433del, R1464G, G1494R, and A1553P). In
another embodiment, at least one mutation selected from the group
consisting of G1128A, R1192P, R1275Q, D1091N, M1166R, I1171N, F1174I,
F1174L, F1245C, F1245V, and I1250T. In yet another embodiment, at least
one of the mutations is to amino acid R1275 and/or F1174, particularly at
least one of R1275Q, F1174I, and F1174L. The presence of at least one of
the above mutations is indicative of neuroblastoma or at least an
increased risk of developing neuroblastoma in the patient. The presence
of at least one of the above mutations is also indicative of a poor
prognosis with increased risk of metastasis and higher risk of death.
While the above mutations can be detected by sequencing the ALK protein
in a biological sample obtained from a subject, it is preferred that the
nucleic acid molecule encoding ALK is examined in the instant methods
(after obtaining (e.g., isolating) from a biological sample from a
subject). The ability to detect the above mutations in a nucleic acid
molecule/protein are well known in the art and include, without
limitation, sequencing, PCR (e.g., real time PCR; e.g., with mutation
specific primers; optionally with subsequent sequencing or
hybridization), hybridization techniques (e.g., with mutation specific
probes (probes which specifically bind a mutated ALK to the exclusion of
wild-type ALK); e.g., microarrays, Southern, Northern), and antibodies
(e.g., those specific for at least one mutant). In yet another
embodiment, the methods of the instant invention comprise determining the
ALK copy number in the cells of the biological sample obtained from a
subject. A gain or amplification in the ALK copy number compared to
normal human cells is indicative of neuroblastoma or at least an
increased risk of developing neuroblastoma in the patient. The increased
ALK copy number is also indicative of a poor prognosis with increased
risk of metastasis and higher risk of death.
[0037] In still another embodiment, the methods of the instant invention
comprise determining if the ALK is phosphorylated. In one embodiment, the
ALK is phosphorylated to greater levels than ALK from a normal human
(i.e., one that does not have cancer, particularly neuroblastoma). The
ALK may be phosphorylated at positions that are not phosphorylated in
normal humans and/or phosphorylated to greater levels (greater frequency)
than ALK in normal humans. For example, as described hereinbelow, the
constitutive phosphorylation (increased levels of phosphorylation
compared to normal humans) of tyrosine at position 1604 of ALK is
indicative of neuroblastoma or at least an increased risk of developing
neuroblastoma in the patient. The increased ALK phosphorylation is also
indicative of a poor prognosis with increased risk of metastasis and
higher risk of death.
[0038] According to another aspect of the instant invention, the above
methods for identifying, diagnosing, or prognosing cancer (particularly
neuroblastoma) in a patient, further comprises identifying mutations in
the phox2B gene/protein (e.g., 676delG) or amplification of the phoX2B
gene/protein (see, e.g., Mosse et al. (2004) Am. J. Hum. Genet.,
75:727-730; Rabbe et al. (2008) Oncogene 27:469-476).
[0039] In accordance with another aspect of the instant invention, methods
for treating cancer, particularly a neuroblastoma, in a patient are
provided, where the method comprises the administration of a composition
comprising at least one ALK inhibitor (e.g., an inhibitor of ALK kinase
activity) and at least one pharmaceutically acceptable carrier. The
method may further comprise determining the particular ALK alteration of
the patient prior to administration (see above) and administering the ALK
inhibitor most effective for the ALK alteration identified (see below).
Examples of ALK inhibitors include, without limitation, ALK siRNA and/or
antisense molecules, small molecule inhibitors, PF-02341066 (Pfizer),
TAE684 (Novartis), and CEP-14083 (Cephalon). The methods may also
comprise the administration of an antibody (or fragment thereof) specific
for ALK (e.g., monoclonal antibodies). In a particular embodiment, the
antiboilies are specific for the extracellular domain of ALK (e.g., the
extracellular domain that remains after proteolytic cleavage from the 220
kDa to 140 kDa species). The antibodies may be administered separately
(before, after, or at the same time as the ALK inhibitor) or in the same
composition. The methods may also comprise the administration of at least
one other chemotherapeutic agent and/or be administered in coordination
with another chemotherapeutic agent or therapy (e.g., chemotherapy). The
chemotherapeutic agent may be administered separately (before, after, or
at the same time as the ALK inhibitor) or in the same composition. The
compositions may be administered by any method such as, for example,
intravenous injection into the blood stream, oral administration, or by
subcutaneous, intramuscular or intraperitoneal injection. As stated
hereinabove, the methods may also further comprise first screening the
subject to determine the ALK mutation (including amplification of copy
number) present in the subject as described hereinabove and selecting the
appropriate ALK inhibitor for the identified mutation to administer to
the patient (see below).
[0040] In accordance with another aspect of the instant invention, methods
of identifying an agent which is therapeutic for the treatment of
neuroblastoma are provided. In a particular embodiment, the method
comprises contacting cells comprising mutations in ALK or an
amplification of ALK with at least one agent and determining the ALK
activity, wherein a reduction in ALK activity indicates the agent is a
therapeutic agent for treating neuroblastoma. In another embodiment, the
method comprises contacting cells comprising mutations in ALK or an
amplification of ALK with at least one agent and determining the ability
of the agent to inhibit proliferation of the cells (e.g., determining
IC.sub.50), wherein a reduction in proliferation indicates the agent is a
therapeutic agent for treating a neuroblastoma characterized by the ALK
mutation of the cells.
[0041] In accordance with another aspect of the present invention,
microarrays for detecting ALK and/or the ALK mutants described
hereinabove are provided. In a particular embodiment, the microarray
comprises antibodies specific for ALK and/or the ALK mutants described
hereinabove. In a preferred embodiment, the microarray comprises
oligonucleotide probes which recognize ALK and/or the ALK mutants
described hereinabove. The microarrays may comprise oligonucleotide
probes which specifically hybridize with at least 2, at least 5, at least
10, or all of the above ALK mutants. In a particular embodiment, the
microarray comprises oligonucleotide probes wherein each probe (or
coordinate on the microarray) specifically hybridizes with a single ALK
mutant (e.g., a single nucleotide change, a single amino acid change
encompassing all codons of the amino acid change, or all changes to a
single amino acid position). In a particular embodiment, the
oligonucleotide probe is completely complementary to ALK (e.g., SEQ ID
NO: 6) except for the mutation. In yet another embodiment, the
oligonucleotide is about 10, 15, 20, 25, or 30 to about 40, 50, 75, or
100 nucleotides in length. In a particular embodiment, the
oligonucleotide probes span an ALK mutant above, particularly so that the
mutation is in the middle of the probe (e.g., within the middle third of
the probe). In another embodiment, the microarray further comprises
probes specific for wild-type ALK and/or PHOX2B (wild-type and/or
mutant). In another embodiment, the microarray is contained within kit
further comprising instruction material and, optionally, at least one
positive control (a nucleic acid molecule recognized by an
oligonucleotide probe of the microarray) and/or at least one negative
control (a nucleic acid molecule not recognized by an oligonucleotide
probe of the microarray).
[0042] Therapeutic methods and compositions
[0043] Recent studies have shown that crizotinib, a dual Met/ALK TKI,
induces remarkable tumor regression in NSCLC patients harboring ALK
translocations (Kwak et al. (2010) N. Engl. J. Med., 363:1693-703).
Crizotinib is also currently in early-phase clinical trial testing in
patients with neuroblastoma. However, preclinical studies have shown that
the impact of crizotinib is highly dependent on ALK copy number and
genotype. For instance, cell lines harboring the F1174L mutation, the
second most common ALK mutation seen in neuroblastoma tumors, are
significantly more resistant to crizotinib than those harboring the most
common mutation, R1275Q (George et al. (2008) Nature 455:975-8; Sasaki et
al. (2010) Cancer Res.). Moreover, resistance mutations in oncogenic ALK
fusions have already emerged in early studies with crizotinib (Sasaki et
al. (2010) Cancer Res.; Engelman et al. (2008) Curr. Opin. Genet. Dev.,
18:73-9; Choi et al. (2010) N. Engl. J. Med., 363:1734-9). These findings
underline a need for developing additional therapeutic options in
neuroblastoma, where well over 50% of high-risk patients will eventually
die of their disease despite major recent therapeutic advances (Maris,
J.M. (2010) N. Engl. J. Med., 362:2202-11; Haupt et al. (2010) J. Clin.
Oncol., 28:2331-8). One such option is immunotherapy. Herein, it is shown
that ALK antibodies inhibit the growth of neuroblastoma cell lines.
Further, the utility of combining ALK antibodies with TKIs is
demonstrated as an important therapeutic strategy in neuroblastoma.
[0044] As taught herein, ALK is a receptor tyrosine kinase aberrantly
expressed in neuroblastoma, a devastating pediatric cancer of the
sympathetic nervous system. Germline and somatically acquired ALK
aberrations induce increased autophosphorylation, constitutive ALK
activation, and increased downstream signaling. Thus, ALK is a tractable
therapeutic target in neuroblastoma which can be susceptible to both
small molecule tyrosine kinase inhibitors and therapeutic antibodies.
Small molecule inhibitors of ALK are available and more are currently
being developed in the clinic, but common ALK mutations in neuroblastoma
appear to show de novo insensitivity, arguing that complementary
approaches must be developed. It is shown herein that antibody targeting
of ALK is a therapeutically relevant strategy for neuroblastoma patients
likely to have ALK-positive tumors. An antagonistic ALK antibody is shown
herein to inhibit cell growth and induces in vitro antibody-dependent
cellular cytotoxicity of human neuroblastoma-derived cell lines.
Cytotoxicity was induced in cell lines harboring either wild-type or
mutated forms of ALK. Treatment of neuroblastoma cells with the dual
Met/ALK inhibitor crizotinib sensitized cells to antibody-induced growth
inhibition by promoting cell surface accumulation of ALK and thus
increasing the accessibility of antigen for antibody binding. These data
clearly show that ALK-targeted immunotherapy is a strong therapeutic
strategy for neuroblastomas with mutated or wild-type ALK.
[0045] Approaches for therapeutically targeting RTKs include monoclonal
antibodies and small molecule tyrosine kinase inhibitors (TKIs), both of
which have led to dramatic increases in survival and time to progression
in certain types of cancer (Zhang (2009) Nat. Rev. Cancer 9:28-39; Weiner
et al. (2010) Nat. Rev. Immunol., 10:317-27). For example, the
trastuzumab antibody was approved for treatment of HER2-overexpressing
breast cancer over 10 years ago, and is thought to have multiple
mechanisms of action including blockade of aberrant signaling and
antibody-dependent cellular cytotoxicity (ADCC) (Hudis, C. A. (2007) N.
Engl. J. Med., 357:39-51). Similarly, the epidermal growth factor
receptor (EGFR) antibody cetuximab inhibits binding of activating ligands
and induces ADCC (Kurai et al. (2007) Clin. Cancer Res., 13:1552-61).
Clinical activity of TKIs that inhibit HER2 and EGFR has been amply
demonstrated. Moreover, these TKIs have been used with HER2- and
EGFR-targeted antibodies in breast and lung cancer, respectively
(Scaltriti et al. (2009) Oncogene 28:803-14; Regales et al. (2009) J.
Clin. Invest., 119:3000-10; Xia et al. (2005) Oncogene 24:6213-21).
[0046] As stated herein, a recent phase 3 clinical trial using antibodies
against the disialoganglioside GD2, which is almost uniformly expressed
on neuroblastoma cell surfaces, has shown the promise of intensive
targeted immunotherapy in neuroblastoma (Yu et al. (2010) N. Engl. J.
Med., 363:1324-34). It is shown herein that ALK RTK is also expressed in
the vast majority of neuroblastoma cases, indicating that it represents
another tractable immunotherapy target. Moreover, like GD2, ALK
expression is largely limited to tumor tissue (Iwahara et al. (1997)
Oncogene 14:439-49), making it an ideal target for immunotherapy while
minimizing the risk of cytotoxicity in non-malignant tissue of patients
treated with ALK antibodies.
[0047] Like the GD2 antibody, and several clinically successful antibodies
such as trastuzumab and cetuximab, it was found herein that an ALK
antibody can mediate ADCC of ALK-positive neuroblastoma cells. In the in
vitro ADCC system, neuroblastoma cells were killed when treated with 1
.mu.g/ml anti-ALK antibody, a lower dose than the 10 .mu.g/ml clinically
achieved in trastuzumab-treated breast cancer patients (Baselga et al.
(1996) J. Clin. Oncol., 14:737-44), and well below the trough plasma
antibody concentrations achieved in two phase I studies of lung cancer
patients treated with cetuximab (Baselga et al. (2000) J. Clin. Oncol.,
18:904-14; Robert et al. (2001) J. Clin. Oncol., 19:3234-43). The
experiments were not designed to determine the optimal ADCC dose, but
nonetheless show that antibody targeting of ALK is an important
therapeutic avenue based on its ADCC effects alone. Additional studies
may be performed to determine the minimum ALK antibody dose at which ADCC
can be induced, the range of effective concentrations, and the dependence
of ADCC sensitivity on ALK expression level and genotype.
[0048] Unlike GD2 antibodies, those that target ALK can bind and inhibit
an oncogenic growth factor receptor--permitting an additional immune
cell-independent component of its inhibitory mechanism, through
inactivation of a constitutively activated receptor. ALK overexpression
or mutation leads to its hyper-activation, autophosphorylation and
elevated down-stream signaling (Osajima-Hakomori et al. (2005) Am. J.
Pathol., 167:213-22), as also seen for HER2 and EGFR in breast and lung
cancer (Yarden et al. (2001) Nat. Rev. Mol. Cell Biol., 2:127-37).
Indeed, the oncogenic role of full-length ALK in neuroblastoma was
originally discovered when activating mutations in ALK, which occur in
roughly 8% of patient tumors, were discovered in the germline of patients
with the hereditary form of neuroblastoma, and were subsequently found to
be somatically acquired (George et al. (2007) PLoS One 2:e255;
Janoueix-Lerosey et al. (2008) Nature 455:967-70; Mosse et al. (2008)
Nature 455:930-5; Chen et al. (2008) Nature 455:971-4). It has also been
shown that whereas native ALK expression levels predict improved
survival, high levels of ALK expression (which promotes its activation)
are associated with decreased survival (see also De Brouwer et al. (2010)
Clin. Cancer Res., 16:4353-62). Thus, ALK signaling--enhanced by mutation
or overexpression--appears to play an important role in initiation and/or
maintenance of neuroblastoma. ALK inhibition with the TKI crizotinib is
likely to be an important tool in treating ALK-dependent neuroblastoma,
but it is already clear that certain ALK-activating mutations reduce
sensitivity to this drug. Antagonistic ALK antibodies provide a superior
approach to ALK inhibition. It is shown herein that an antagonist ALK
antibody inhibits growth of neuroblastoma cells over a range of doses,
all of which are below (or equal to) those reported to be clinically
achievable in patients with trastuzumab or cetuximab. The ALK antibody
inhibits growth in neuroblastoma cell lines that harbor either
amplified/over expressed ALK (NB1) or ALK with the most common
constitutively activating mutations (R1275Q in 1643 cells, and F1174L in
SY5Y cells). Notably, SY5Y cells are relatively resistant to
TKI-targeting of ALK, but respond to antibody inhibition. ALK antibody
therapy is, therefore, relevant for patient tumors exhibiting a broad
range of ALK expression levels and aberrations.
[0049] It is also demonstrated herein that dual targeting of ALK with both
antibody and TKI therapeutics produces superior results. Dual targeting
has been used with other oncogenic RTKs (Scaltriti et al. (2009) Oncogene
28:803-14; Xia et al. (2005) Oncogene 24:6213-21; Johns et al. (2003)
Proc. Natl. Acad. Sci., 100:15871-6; Konecny et al. (2006) Cancer Res.,
66:1630-9; Matar et al. (2004) Clin. Cancer Res., 10:6487-501). For
example, for NSCLC expressing erlotinib-resistant EGFR.sup.T790M, such
dual targeting induced tumor regression (Regales et al. (2009) J. Clin.
Invest., 119:3000-10). For ALK-expressing neuroblastoma cell lines,
crizotinib treatment enhances cell surface expression of ALK, leading
both to enhanced ADCC and elevated immune cell-independent growth
inhibition and cytotoxicity. For F1174L-expressing SY5Y cells, for
example, combined antibody/TKI treatment led to almost complete growth
inhibition, and induced a significantly higher level of apoptosis than
either crizotinib or antibody alone. Importantly, the antibody/TKI
combination therapy demonstrated efficacy at low (10 nM) doses of
crizotinib and antibody reduced the IC.sub.50 for crizotinib treatment by
half. This shows that dual ALK targeting is a relevant therapeutic
strategy for decreasing the dose-dependent toxicities associated with TKI
therapy and can delay or prevent TKI resistance.
[0050] In accordance with the instant invention, methods for inhibiting,
reducing the progression of, and/or treating cancer, particularly a
neuroblastoma, in a subject (e.g., human or animal) are provided. The
neuroblastoma may be resistant to an ALK inhibitor (e.g., crizotinib).
[0051] In a particular embodiment, the methOd comprises the administration
of at least one ALK antibody to a subject. In a particular embodiment,
the antibody is immunologically specific for the extracellular domain of
ALK (e.g., the extracellular domain that remains after proteolytic
cleavage from the 220 kDa to 140 kDa species, or amino acids 19-1038).
ALK amino acid and nucleotide sequences are provided, e.g., in FIG. 9 as
well as U.S. Pat. No. 5,770,421; GenBank Gene ID: 238; and GenBank
Accession Nos. NM 004304.4 and NP 004295.2. Examples of ALK antibodies
are provided, for example, in Moog-Lutz et al. (.I. Biol. Chem.,
280:26039-26048), Bernard-Pierrot et al. (J. Biol. Chem. (2002)
277:32071-32077), U.S. Patent Application Publication No. 2008/0118512,
U.S. Patent Application Publication No. 2001/0021505, U.S. Patent
5,770,421; Motegi et al. (J. Cell Sci. (2004) 117:3319-29), and Mazot et
al. (Oncogene (2011) doi:10.1038/onc.2010.595).
[0052] Anti-ALK antibody of the instant invention may be modified. For
example, the antibodies may be humanized to reduce immunogenicity (Jones
et al. (1986) Nature 321:522-5), de-fucosylated to maximize ADCC (Niwa et
al. (2005) Clin. Cancer Res., 11:2327-36), and/or conjugated to
immunostimulatory cytokines such as IL-2 or cytotoxic agents (Hughes, B.
(2010) Nat. Rev. Drug Discov., 9:665-7). In a particular embodiment, the
anti-ALK antibody is operably linked (e.g., coupled or conjugated) to
reagents that induce cell death. For example, the antibody may be linked
to a cytotoxic molecule, a radioisotope, drug, and/or a chemotherapeutic
agent. Cytotoxic molecules include, without limitation, complement (e.g.,
mouse, rat, rabbit, guinea pig, cow, horse, and human), nanoparticles and
nanotubes (e.g., heat sensitive carbon nanocrystals; see e.g.,
Chakravarty et al. (2008) PNAS 105:8697-8702) and Cho et al. (2008) Clin.
Cancer Res., 14:1310-1316), cytoxic antibiotics (e.g., calicheamicin),
cationic amphipathic lytic peptides (e.g., KLA and PTP (prostate-specific
membrane antigen-targeting peptide)), radionuclides, and toxins. Toxins
can be derived from various sources, such as plants, bacteria, animals,
and humans or be synthetic toxins (drugs), and include, without
limitation, saprin, ricin (e.g., ricin A), abrin, ethidium bromide,
diptheria toxin, Pseudomonas exotoxin, PE40, PE38, saporin, gelonin,
RNAse, peptide nucleic acids (PNAs), ribosome inactivating protein (RIP)
type-1 or type-2, pokeweed anti-viral protein (PAP), bryodin, momordin,
chemotherapeutic agents, and bouganin. Radionuclides (radioisotopes) of
the instant invention include, without limitation, positron-emitting
isotopes and alpha-, beta-, gamma-, Auger- and low energy
electron-emitters. In a particular embodiment, the radionuclides are
alpha-emitters or auger-emitters. The radioisotopes include, without
limitation: .sup.13N, 18F, .sup.32P, .sup.64Cu, .sup.66Ga, .sup.67Ga,
.sup.68Ga, .sup.67Cu, .sup.77Br, .sup.80mBr, .sup.82Rb, .sup.86Y,
.sup.90Y, .sup.95Ru, .sup.97Ru, .sup.99mTc, .sup.103Ru, .sup.105Ru,
.sup.111In, .sup.113mIn, .sup.113Sn, .sup.121mTe, .sup.122mTe,
.sup.125mTe, .sup.123I, .sup.124I, .sup.125I, .sup.126I, .sup.131I,
.sup.133I, .sup.165Tm, .sup.167Tm, .sup.168Tm, .sup.1777Lu, .sup.186Re,
.sup.188Re, .sup.195mHg, .sup.211At, .sup.212Bi, .sup.213Bi, .sup.213Bi,
and .sup.225Ac. In yet another embodiment, the radionuclide containing
molecule can be administered with a radiosensitizer.
[0053] In a particular embodiment, the method further comprises the
administration of at least one ALK inhibitor (e.g., an inhibitor of ALK
kinase activity) to the subject. The ALK inhibitor may be administered
before, after, and/or simultaneously (e.g., in the same composition or in
different compositions) with the ALK antibody. In a particular
embodiment, the ALK inhibitor is a small molecule inhibitor (e.g., an
ATP-competitive, small-molecule inhibitor of the receptor tyrosine
kinase). Examples of ALK inhibitors include, without limitation,
crizotinib (PF-02341066, Pfizer), LDK378 (Novartis), TAE684 (Novartis),
CEP-14083 (Cephalon, Frazer, Pa.), CEP-37440 (Cephalon), CEP-28122
(Cephalon), CEP-14513 (Cephalon), AF802 (Chugai (Japan), Roche), AP26113
(Ariad; Cambridge, Mass.), and the compounds in U.S. Pat. Nos. 7,601,716;
7,910,585; 7,893,074; and 7,671,063, and U.S. Patent Application
Publication Nos. 2009/0131436, 2009/0221555, and 2009/0286778. In a
particular embodiment, the ALK inhibitor is crizotinib.
[0054] The methods may also comprise the administration of at least one
other chemotherapeutic agent and/or be administered in coordination with
another chemotherapeutic agent or therapy (e.g., chemotherapy, radiation,
etc.). In a particular embodiment, disialoganglioside GD2 antibodies (Yu
et al. (2010) N. Engl. J. Med., 363:1324-34) are also administered. The
chemotherapeutic agent may be administered separately (before, after, or
at the same time as the ALK inhibitor and/or ALK antibody) or in the same
composition. As stated hereinabove, the methods may also further comprise
first screening the subject to determine the ALK mutation (including
amplification of copy number) present in the subject as described
hereinabove and selecting the appropriate ALK inhibitor and/or antibody
for the identified mutation to administer to the patient.
[0055] Compositions comprising the above ALK therapeutics are also
encompassed by the instant invention. In a particular embodiment, the
composition comprises at least one ALK antibody and at least one
pharmaceutically acceptable carrier. The composition may further comprise
at least one ALK inhibitor, chemotherapeutic agent, and/or at least one
GD2 antibody. In yet another embodiment, kits comprising at least one of
the above compositions are encompassed by the instant invention. For
example, the kit may comprise a first composition comprising at least one
ALK antibody and at least one carrier and a second composition comprising
at least one ALK inhibitor and at least one carrier.
[0056] The compositions described herein will generally be administered to
a patient as a pharmaceutical preparation. The term "patient" as used
herein refers to human or animal subjects. These compositions may be
employed therapeutically, under the guidance of a physician.
[0057] The compositions of the instant invention may be conveniently
formulated for administration with any pharmaceutically acceptable
carrier(s). For example, the agents may be formulated with an acceptable
medium such as water, buffered saline, ethanol, polyol (for example,
glycerol, propylene glycol, liquid polyethylene glycol and the like),
dimethyl sulfoxide (DMSO), oils, detergents, suspending agents or
suitable mixtures thereof. The concentration of the agents in the chosen
medium may be varied and the medium may be chosen based on the desired
route of administration of the pharmaceutical preparation. Except insofar
as any conventional media or agent is incompatible with the agents to be
administered, its use in the pharmaceutical preparation is contemplated.
[0058] The dose and dosage regimen of compositions according to the
invention that are suitable for administration to a particular patient
may be determined by a physician considering the patient's age, sex,
weight, general medical condition, and the specific condition for which
the composition is being administered and the severity thereof. The
physician may also take into account the route of administration, the
pharmaceutical carrier, and the composition's biological activity.
[0059] Selection of a suitable pharmaceutical preparation will also depend
upon the mode of administration chosen. For example, the compositions of
the invention may be administered intravenously. In this instance, a
pharmaceutical preparation comprises the agents dispersed in a medium
that is compatible with intravenous injection.
[0060] Compositions of the instant invention may be administered by any
method. For example, the compositions of the instant invention can be
administered, without limitation, parenterally, subcutaneously, orally
(e.g., liquid or pill/capsule/tablet form), topically, pulmonarily,
intravenously, intraperitoneally, intrathecally, epidurally,
intramuscularly, intradermally. In a particular embodiment, the
compositions are administered intravenously or orally. Pharmaceutical
preparations for injection and oral administration are known in the art.
If injection is selected as a method for administering the composition,
steps must be taken to ensure that sufficient amounts of the molecules
reach their target cells to exert a biological effect.
[0061] Pharmaceutical compositions containing an agent of the present
invention as the active ingredient in intimate admixture with a
pharmaceutically acceptable carrier can be prepared according to
conventional pharmaceutical compounding techniques. The carrier may take
a wide variety of forms depending on the form of preparation desired for
administration, e.g., intravenous.
[0062] A pharmaceutical preparation of the invention may be formulated in
dosage unit form for ease of administration and uniformity of dosage.
Dosage unit form, as used herein, refers to a physically discrete unit of
the pharmaceutical preparation appropriate for the patient undergoing
treatment. Each dosage should contain a quantity of active ingredient
calculated to produce the desired effect in association with the selected
pharmaceutical carrier. Procedures for determining the appropriate dosage
unit are well known to those skilled in the art. Dosage units may be
proportionately increased or decreased based on the weight of the
patient. Appropriate concentrations for alleviation of a particular
pathological condition may be determined by dosage concentration curve
calculations, as known in the art.
[0063] In accordance with the present invention, the appropriate dosage
unit for the administration of compositions of the instant invention may
be determined by evaluating the toxicity of the molecules or cells in
animal models. Various concentrations of agents in pharmaceutical
preparations may be administered to mice, and the minimal and maximal
dosages may be determined based on the beneficial results and side
effects observed as a result of the treatment. Appropriate dosage unit
may also be determined by assessing the efficacy of the agent treatment
in combination with other standard drugs. The dosage units of the
compositions may be determined individually or in combination with each
treatment according to the effect detected.
[0064] The pharmaceutical preparation comprising the agents of the instant
invention may be administered at appropriate intervals, for example, at
least once or twice a day or more until the pathological symptoms are
reduced or alleviated, after which the dosage may be reduced to a
maintenance level. The appropriate interval in a particular case would
normally depend on the condition of the patient.
[0065] Definitions
[0066] As used herein, a "biological sample" refers to a sample of
biological material obtained from a subject, preferably a human subject,
including a tissue, a tissue sample, a cell sample, a tumor sample, and a
biological fluid, e.g., blood or urine. A biological sample may be
obtained in the form of, e.g., a tissue biopsy, such as, an aspiration
biopsy, a brush biopsy, a surface biopsy, a needle biopsy, a punch
biopsy, an excision biopsy, an open biopsy, an incision biopsy and an
endoscopic biopsy.
[0067] As used herein, "diagnose" refers to detecting and identifying a
disease in a subject. The term may also encompass assessing or evaluating
the disease status (progression, regression, stabilization, response to
treatment, etc.) in a patient known to have the disease.
[0068] As used herein, the term "prognosis" refers to providing
information regarding the impact of the presence of cancer (e.g., as
determined by the diagnostic methods of the present invention) on a
subject's future health (e.g., expected morbidity or mortality, the
likelihood of getting cancer, and the risk of metastasis). In other
words, the term "prognosis" refers to providing a prediction of the
probable course and outcome of a cancer or the likelihood of recovery
from the cancer.
[0069] The term "treat" as used herein refers to any type of treatment
that imparts a benefit to a patient afflicted with a disease, including
improvement in the condition of the patient (e.g., in one or more
symptoms), delay in the progression of the condition, etc.
[0070] The phrase "effective amount" refers to that amount of therapeutic
agent that results in an improvement in the patient's condition.
"Pharmaceutically acceptable" indicates approval by a regulatory agency
of the Federal or a state government or listed in the U.S. Pharmacopeia
or other generally recognized pharmacopeia for use in animals, and more
particularly in humans.
[0071] A "carrier" refers to, for example, a diluent, adjuvant,
preservative (e.g., Thimersol, benzyl alcohol), anti-oxidant (e.g.,
ascorbic acid, sodium metabisulfite), solubilizer (e.g., Tween 80,
Polysorbate 80), emulsifier, buffer (e.g., Tris HCl, acetate, phosphate),
water, aqueous solutions, oils, bulking substance (e.g., lactose,
mannitol), excipient, auxilliary agent or vehicle with which an active
agent of the present invention is administered. Suitable pharmaceutical
carriers are described in "Remington's Pharmaceutical Sciences" by E. W.
Martin (Mack Publishing Co., Easton, Pa.); Gennaro, A. R., Remington: The
Science and Practice of Pharmacy, 20th Edition, (Lippincott, Williams and
Wilkins), 2000; Liberman, et al., Eds., Pharmaceutical Dosage Forms,
Marcel Decker, New York, N.Y., 1980; and Kibbe, et al., Eds., Handbook of
Pharmaceutical Excipients (3rd Ed.), American Pharmaceutical Association,
Washington, 1999.
[0072] As used herein, a "conservative" amino acid substitution/mutation
refers to substituting a particular amino acid with an amino acid having
a side chain of similar nature (i.e., replacing one amino acid with
another amino acid belonging to the same group). A "non-conservative"
amino acid substitution/mutation refers to replacing a particular amino
acid with another amino acid having a side chain of different nature
(i.e., replacing one amino acid with another amino acid belonging to a
different group). Groups of amino acids having a side chain of similar
nature are known in the art and include, without limitation, basic amino
acids (e.g., lysine, arginine, histidine);
[0073] acidic amino acids (e.g., aspartic acid, glutamic acid); neutral
amino acids (e.g., glycine, asparagine, glutamine, serine, threonine,
tyrosine, cysteine, alanine, valine, leucine, isoleucine, proline,
phenylalanine, methionine, tryptophan); amino acids having a polar side
chain (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine,
cysteine); amino acids having a non-polar side chain (e.g., alanine,
valine, leucine, isoleucine, proline, phenylalanine, methionine,
tryptophan); amino acids having an aromatic side chain (e.g.,
phenylalanine, tryptophan, histidine); amino acids having a side chain
containing a hydroxyl group (e.g., serine, threonine, tyrosine), and the
like.
[0074] As used herein, the term "amplification" when used in reference to
copy number refers to the condition in which the copy number of a nucleic
acid sequence is greater than the copy number of a control sequence. In
other words, amplification indicates that the ratio of a particular
nucleic acid sequence is greater than 1:1 when compared to a control
sequence (e.g., 1.1:1, 1.2:1, or 1.3:1).
[0075] The term "probe" as used herein refers to an oligonucleotide,
polynucleotide or nucleic acid, either RNA or DNA, whether occurring
naturally as in a purified restriction enzyme digest or produced
synthetically, which is capable of annealing with or specifically
hybridizing to a nucleic acid with sequences complementary to the probe.
A probe may be either single-stranded or double-stranded. The exact
length of the probe will depend upon many factors, including temperature,
source of probe and use of the method. For example, for diagnostic
applications, depending on the complexity of the target sequence, the
oligonucleotide probe typically contains about 10-100, about 10-50, about
15-30, about 15-25, about 20-50, or more nucleotides, although it may
contain fewer nucleotides. The probes herein may be selected to be
complementary to different strands of a particular target nucleic acid
sequence. This means that the probes must be sufficiently complementary
so as to be able to "specifically hybridize" or anneal with their
respective target strands under a set of pre-determined conditions.
Therefore, the probe sequence need not reflect the exact complementary
sequence of the target, although they may. For example, a
non-complementary nucleotide fragment may be attached to the 5' or 3' end
of the probe, with the remainder of the probe sequence being
complementary to the target strand. Alternatively, non-complementary
bases or longer sequences can be interspersed into the probe, provided
that the probe sequence has sufficient complementarity with the sequence
of the target nucleic acid to anneal therewith specifically.
[0076] The term "primer" as used herein refers to an oligonucleotide,
either RNA or DNA, either single-stranded or double-stranded, either
derived from a biological system, generated by restriction enzyme
digestion, or produced synthetically which, when placed in the proper
environment, is able to functionally act as an initiator of
template-dependent nucleic acid synthesis. When presented with an
appropriate nucleic acid template, suitable nucleoside triphosphate
precursors of nucleic acids, a polymerase enzyme, suitable cofactors and
conditions such as appropriate temperature and pH, the primer may be
extended at its 3' terminus by the addition of nucleotides by the action
of a polymerase or similar activity to yield a primer extension product.
The primer may vary in length depending on the particular conditions and
requirement of the application. For example, in diagnostic applications,
the oligonucleotide primer is typically about 10-25 or more nucleotides
in length. The primer must be of sufficient complementarity to the
desired template to prime the synthesis of the desired extension product,
that is, to be able to anneal with the desired template strand in a
manner sufficient to provide the 3' hydroxyl moiety of the primer in
appropriate juxtaposition for use in the initiation of synthesis by a
polymerase or similar enzyme. It is not required that the primer sequence
represent an exact complement of the desired template. For example, a
non-complementary nucleotide sequence may be attached to the 5' end of an
otherwise complementary primer.
[0077] Alternatively, non-complementary bases may be interspersed within
the oligonucleotide primer sequence, provided that the primer sequence
has sufficient complementarity with the sequence of the desired template
strand to functionally provide a template-primer complex for the
synthesis of the extension product. Polymerase chain reaction (PCR) has
been described in U.S. Pat. Nos. 4,683,195, 4,800,195, and 4,965,188, the
entire disclosures of which are incorporated by reference herein.
[0078] With respect to single stranded nucleic acids, particularly
oligonucleotides, the term "specifically hybridizing" refers to the
association between two single-stranded nucleotide molecules of
sufficiently complementary sequence to permit such hybridization under
pre-determined conditions generally used in the art (sometimes termed
"substantially complementary"). In particular, the term refers to
hybridization of an oligonucleotide with a substantially complementary
sequence contained within a single-stranded DNA molecule of the
invention, to the substantial exclusion of hybridization of the
oligonucleotide with single-stranded nucleic acids of non-complementary
sequence. Appropriate conditions enabling specific hybridization of
single stranded nucleic acid molecules of varying complementarity are
well known in the art.
[0079] For instance, one common formula for calculating the stringency
conditions required to achieve hybridization between nucleic acid
molecules of a specified sequence homology is set forth below (Sambrook
et al., 1989, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor
Laboratory Press):
Tm=81.5.degree. C.+16.6 Log [Na+]+0.41(% G+C)-0.63 (% formamide)-600/#bp
in duplex
[0080] As an illustration of the above formula, using [Na+]=[0.368] and
50% formamide, with GC content of 42% and an average probe size of 200
bases, the Tm is 57.degree. C. The Tm of a DNA duplex decreases by
1-1.5.degree. C. with every 1% decrease in homology. Thus, targets with
greater than about 75% sequence identity would be observed using a
hybridization temperature of 42.degree. C.
[0081] The stringency of the hybridization and wash depend primarily on
the salt concentration and temperature of the solutions. In general, to
maximize the rate of annealing of the probe with its target, the
hybridization is usually carried out at salt and temperature conditions
that are 20-25.degree. C. below the calculated Tm of the hybrid. Wash
conditions should be as stringent as possible for the degree of identity
of the probe for the target. In general, wash conditions are selected to
be approximately 12 20.degree. C. below the Tm of the hybrid. In regards
to the nucleic acids of the current invention, a moderate stringency
hybridization is defined as hybridization in 6.times. SSC, 5.times.
Denhardt's solution, 0.5% SDS and 100 .mu.g/ml denatured salmon sperm DNA
at 42.degree. C., and washed in 2.times. SSC and 0.5% SDS at 55.degree.
C. for 15 minutes. A high stringency hybridization is defined as
hybridization in 6.times. SSC, 5.times. Denhardt's solution, 0.5% SDS and
100 .mu.g/ml denatured salmon sperm DNA at 42.degree. C., and washed in
1.times. SSC and 0.5% SDS at 65.degree. C. for 15 minutes. A very high
stringency hybridization is defined as hybridization in 6.times. SSC,
5.times. Denhardt's solution, 0.5% SDS and 100 .mu.g/ml denatured salmon
sperm DNA at 42.degree. C., and washed in 0.1.times. SSC and 0.5% SDS at
65.degree. C. for 15 minutes.
[0082] An "antibody" or "antibody molecule" is any immunoglobulin,
including antibodies and fragments thereof, that binds to a specific
antigen. The term includes polyclonal, monoclonal, chimeric, single
domain (Dab) and bispecific antibodies. As used herein, antibody or
antibody molecule contemplates recombinantly generated intact
immunoglobulin molecules and molecules comprising immunologically active
portions of an immunoglobulin molecule such as, without limitation: Fab,
Fab', F(ab')2, F(v), scFv, scFv2, scFv-Fc, minibody, diabody, tetrabody,
and single variable domain (e.g., variable heavy domain, variable light
domain).
[0083] With respect to antibodies, the term "immunologically specific"
refers to antibodies that bind to one or more epitopes of a protein or
compound of interest, but which do not substantially recognize and bind
other molecules in a sample containing a mixed population of antigenic
biological molecules.
[0084] The term "isolated" may refer to a compound or complex that has
been sufficiently separated from other compounds with which it would
naturally be associated. "Isolated" is not meant to exclude artificial or
synthetic mixtures with other compounds or materials, or the presence of
impurities that do not interfere with fundamental activity or ensuing
assays, and that may be present, for example, due to incomplete
purification, or the addition of stabilizers.
[0085] As used herein, an "instructional material" includes a publication,
a recording, a diagram, or any other medium of expression which can be
used to communicate the usefulness of the composition of the invention
for performing a method of the invention.
[0086] The phrase "solid support" refers to any solid surface including,
without limitation, any chip (for example, silica-based, glass, or gold
chip), glass slide, membrane, plate, bead, solid particle (for example,
agarose, sepharose, polystyrene or magnetic bead), column (or column
material), test tube, or microtiter dish.
[0087] As used herein, the term "microarray" refers to an ordered
arrangement of hybridizable array elements. The array elements are
arranged so that there are at least one or more different array elements
on a solid support. Preferably, the array elements comprise
oligonucleotide probes.
[0088] As used herein, the term "small molecule" refers to a substance or
compound that has a relatively low molecular weight (e.g., less than
2,000). Typically, small molecules are organic, but are not proteins,
polypeptides, or nucleic acids.
[0089] Chemotherapeutic agents are compounds that exhibit anticancer
activity and/or are detrimental to a cell (e.g., a toxin). Suitable
chemotherapeutic agents include, but are not limited to: toxins (e.g.,
saporin, ricin, abrin, ethidium bromide, diptheria toxin, and Pseudomonas
exotoxin); taxanes; alkylating agents (e.g., temozolomide, nitrogen
mustards such as chlorambucil, cyclophosphamide, isofamide,
mechlorethamine, melphalan, and uracil mustard; aziridines such as
thiotepa; methanesulphonate esters such as busulfan; nitroso ureas such
as carmustine, lomustine, and streptozocin; platinum complexes (e.g.,
cisplatin, carboplatin, tetraplatin, ormaplatin, thioplatin, satraplatin,
nedaplatin, oxaliplatin, heptaplatin, iproplatin, transplatin, and
lobaplatin); bioreductive alkylators such as mitomycin, procarbazine,
dacarbazine and altretamine); DNA strand-breakage agents (e.g.,
bleomycin); topoisomerase II inhibitors (e.g., amsacrine, menogaril,
amonafide, dactinomycin, daunorubicin, N,N-dibenzyl daunomycin,
ellipticine, daunomycin, pyrazoloacridine, idarubicin, mitoxantrone,
m-AMSA, bisantrene, doxorubicin (adriamycin), deoxydoxorubicin, etoposide
(VP-16), etoposide phosphate, oxanthrazole, rubidazone, epirubicin,
bleomycin, and teniposide); DNA minor groove binding agents (e.g.,
plicamydin); antimetabolites (e.g., folate antagonists such as
met
hotrexate and trimetrexate); pyrimidine antagonists such as
fluorouracil, fluorodeoxyuridine, CB3717, azacitidine, cytarabine, and
floxuridine; purine antagonists such as mercaptopurine, 6-thioguanine,
fludarabine, pentostatin; asparginase; and ribonucleotide reductase
inhibitors such as hydroxyurea); anthracyclines; and tubulin interactive
agents (e.g., vincristine, vinblastine, and paclitaxel (Taxol.RTM.)).
[0090] Radiation therapy refers to the use of high-energy radiation from
x-rays, gamma rays, neutrons, protons and other sources to target cancer
cells. Radiation may be administered externally or it may be administered
using radioactive material given internally. Chemoradiation therapy
combines chemotherapy and radiation therapy.
[0091] The following examples are provided to illustrate certain
embodiments of the invention. They are not intended to limit the
invention in any way.
EXAMPLE 1
Methods
SUMMARY
[0092] Twenty probands with neuroblastoma and a family history of the
disease were identified for study. Eight pedigrees had 3 or more affected
individuals; six pedigrees contained only two affected individuals, but
of first degree relation; and six pedigrees consisted of only two
affected individuals, but of second, third, or >fourth degree
relationship. A total of 176 individuals (49 affected with neuroblastoma)
were genotyped genome-wide, and two families were excluded due to
insufficient DNA for genotyping. Marker data was simulated under a model
of genetic homogeneity and autosomal dominant inheritance, and the data
was analyzed using an affected-only approach comparable to the model-free
approach used in the actual linkage analysis. Genotype data were checked
for Mendelian inconsistencies using PEDSTATS (Wigginton et al. (2005)
Bioinformatics, 21:3445-7), and analyzed for linkage using MERLIN
(Abecasis et al. (2002) Nat. Genet., 30:97-101) and LAMP (Li et al.
(2005) Am. J. Hum. Genet., 76:934-49). Regional candidates were
re-sequenced using Sanger methodology. Predictions on the probability
that DNA sequence alterations encode a mutant protein were performed
using a support vector machine-based statistical classifier (Torkamani et
al., (2007) Bioinformatics, 23:2918-25; Torkamani et al. (2008) Cancer
Res., 68:1675-82). Four-hundred-and-ninety-one primary tumor samples, and
27 cell lines were used for whole genome SNP-array analyses (550K) to
determine copy number alterations (Maris et al. (2008) N. Engl. J. Med.,
358:2585-93). mRNA knockdown of ALK and control targets was achieved with
siRNAs against each target. siRNA knockdown effects on substrate adherent
growth was quantified with the RT-CESTm microelectronic cell sensor
system (ACEA, San Diego, Calif.) (Yu et al. (2006) Anal. Chem., 78:35-43;
Cole et al. (2008) Mol. Cancer Res., 6:735-42). Whole cell lysates were
collected from the cell lines and from siALK and siNTC (non targeting
control) treated cells after transfection. Proteins were separated by SDS
PAGE gels and immunoblotted using ALK and Phospho-ALK antibodies.
Research Subjects and Samples
[0093] Families with a history of neuroblastoma in at least one other
relative were eligible to participate. Only germline DNA from the
neuroblastoma pedigrees was studied, as no tumor tissue was available.
Sporadic neuroblastoma tumor samples with matched constitutional DNA were
acquired from the Children's Oncology Group Neuroblastoma Tumor Bank. The
Children's Hospital of Philadelphia Institutional Review Board approved
this research.
Linkage Analysis
[0094] A genome-wide linkage scan was done using the Illumina Linkage IVb
SNP panel. Genotype data were checked for Mendelian inconsistencies using
PEDSTATS (Wigginton et al. (2005) Bioinformatics, 21:3445-7), and
analyzed for linkage using MERLIN (Abecasis et al. (2002) Nat. Genet.,
30:97-101) and LAMP (Li et al. (2005) Am. J. Hum. Genet., 76:934-49). The
genome-wide screen for linkage was performed with both maximum likelihood
allele frequency estimates and model-free analyses. Since the pattern of
inheritance is complex, a model-free approach was used so as not to
assume any specific mode of inheritance. Model-based analyses were
performed for all SNPs included in the critical region under a dominant
mode of inheritance, assuming four different gene frequencies (0.0001,
0.001, 0.01, and 0.1) and dominant transmission with varying penetrance
of the disease across a broad range, from 0.0001 to 0.68. Model-based
linkage analysis was also performed using the method implemented in LAMP,
assuming a prevalence of the disease of 0.000143 (1/7000), and maximizing
the lod-scores over all possible disease models (MOD score analysis). In
every analysis, the critical interval was defined as the region with
associated lod-scores greater than the maximum lod-score minus 3. Since
linkage disequilibrium (LD) among markers is known to inflate the
lod-scores from linkage analysis in the presence of missing founders, its
impact on the lod-scores was assessed at the chromosome 2p critical
interval. To model LD, markers were organized into clusters by means of
Merlin, which uses population haplotype frequencies derived from the
HapMap project (www.hapmap.org/).
DNA Sequencing
[0095] S
hotgun resequencing from templates generated by long PCR for an 18
kilobase region surrounding the MYCN locus was performed using a 454 Life
Sciences instrument (Branford, Conn.) after bi-directional sequencing of
the three coding exons showed no disease causal sequence variations in
the pedigrees. Bi-directional sequencing of ALK coding sequence was
performed in the following distinct sample sets: 1) constitutional DNA
from the proband and an unaffected first degree relative from the twenty
neuroblastoma pedigrees, with repeat sequencing of amplicons containing
any DNA sequence variations and sequencing of amplicons containing
confirmed variations in remaining family members; 2) 27 human
neuroblastoma-derived cell line DNAs maintained at the Children's
Hospital of Philadelphia; 3) tumor DNA from 167 sporadic neuroblastomas
from the Children's Oncology Group tumor bank; and 4) 109 normal
constitutional DNAs from the SNP500Cancer Resource panel purchased from
the Coriell Institute for Medical Research (Camden, NJ). In order to
verify neuroblastoma cell line integrity, all lines were routinely
genotyped (AmpFLSTR Identifiler kit; Applied Biosystems, Foster City,
Calif.), and mycoplasma tested.
Mutation Prediction
[0096] Cancer mutant predictions and analysis were performed as described
(Torkamani et al. (2008) Cancer Res., 68:1675-82). Briefly, a support
vector machine was trained upon common SNPs (presumed neutral) and
congenital disease causing
[0097] SNPs characterized by a variety of sequence, structural, and
phylogenetic parameters. Training and predictions were performed using
somatic mutations occurring within and outside of the kinase catalytic
core separately. The support vector machine-based method was then applied
to the ALK mutants, and the probability that each mutant is a driver was
computed via the support vector machine. The threshold taken for calling
a SNP a driver was taken to be 0.49 for catalytic domain mutations, and
0.53 for all other mutations (Torkamani et al. (2007) Bioinformatics,
23:2918-25). For comparison to previously observed cancer mutations, ALK
mutants were mapped to positions of a catalytic core alignment generated
with characteristic site motifs, and previously observed cancer mutants
mapping to the same positions were noted (Torkamani et al. (2008) Cancer
Res., 68:1675-82).
Tumor Copy Number Analysis
[0098] Tumor samples were assayed on the Illumina Infinium.TM. II
HumanHap550 BeadChip technology (Illumina, San Diego, Calif.), at the
Center for Applied Genomics at the Children's Hospital of Philadelphia. A
total of 750 nanograms of genomic DNA was used as input in each case, and
the assay was performed and data analyzed following the manufacturers
recommendations and as previously described (Maris et al. (2008) N. Engl.
J. Med., 358:2585-93).
Quantitative mRNA Expression
[0099] Relative ALK expression was determined using the 2-.DELTA..DELTA.Ct
method (Livak et al. (2001) Methods 25:402-8), using GAPDH as the
endogenous control and using the second dCT as the lowest expressed cell
line, using methods as previously described (Cole et al. (2008) Mol.
Cancer Res., 6:735-42).
ALK siRNA Knockdown in Neuroblastoma Cell Lines
[0100] A total of 1-5.times.10.sup.4 neuroblastoma cells were plated in
triplicate overnight in antibiotic-free complete media in the 96 well
RT-CESTM microelectronic cell sensor system (ACEA, San Diego, Calif.) (Yu
et al. (2006) Anal. Chem., 78:35-43; Cole et al. (2008) Mol. Cancer Res.,
6:735-42). The cells were then transiently transfected with 200 .mu.l
containing 50 nM of pooled siRNAs (four separate siRNAs per transcript
targeted) against ALK (catalog #M-003103-02), GAPDH (catalog
#D-001140-01-20) negative control, non targeting negative control, or
PLK1 (catalog #M-003290-01) positive control (siGENOME SMARTpool siRNA,
Dharmacon, Lafayette, Colo.) using 0.1% v/v Dharmafect I, according to
the manufacturer's protocol (Dharmacon, Lafayette, Colo.). The four
separate ALK-directed siRNA sense direction sequences are:
TABLE-US-00001
ALK J-003103-10
GGGCCUGUAUACCGGAUAAUU (SEQ ID NO: 1)
ALK J-003103-11
GUGCCAUGCUGCCAGUUAAUU (SEQ ID NO: 2)
ALK J-003103-12
CCGCUUUGCCGAUAGAAUAUU (SEQ ID NO: 3)
ALK J-003103-13
GGAGCCACCUACGUAUUUAUU (SEQ ID NO: 4)
In brief, 35 .mu.L of 1 .mu.M siRNA and 35 .mu.L of serum-free media were
combined with 0.7 .mu.L Dharmafect I in 70 .mu.L of serum-free media and
incubated for 20 minutes at room temperature, and then 560 .mu.L of
antibiotic-free complete media was added. The culture media was gently
removed from the plated cells and replaced by 200 .mu.L of fresh media
containing the siRNA, mock or complete media. Cell growth was monitored
continuously and recorded as a cell index (CI) every 30 minutes for a
minimum of 96 hours. The "Cell Index" (CI) is derived from the change in
electrical impedance as the living cells interact with the biocompatible
microelectrode surface in the microplate well effectively measuring cell
number, shape and adherence. Forty-eight hours after siRNA transfection,
total RNA was extracted from the cells that had been plated in a parallel
96-well plate using the Qiagen (Valencia, Calif.) mini extraction kit,
with DNAase treatment. Two hundred ng of total RNA was oligodT primed and
reverse transcribed using Superscript II reverse transcriptase
(Invitrogen, Carlsbad, Calif.). ALK, HPRT, GAPDH and PPIB expression
levels were measured by quantitative RT-PCR using Taqmang gene expression
assays (ABI, Foster City, Calif.), quantified on corresponding standard
curves and normalized to the geometric mean of the three housekeeping
genes. Two independent experiments were performed in triplicate. Growth
inhibition of the neuroblastoma cell lines was determined by comparing
the siRNA against ALK growth curve to that against GAPDH at the time of
maximum cell index (CI.sub.max): % growth
inhibition=(1-C.sub.siALK/CI.sub.siGAPDH).times.100. ALK and GAPDH
knockdown was determined by comparing the relative ALK expression: %
knockdown=(1-ALK.sub.siALK/ALK.sub.sicoNTRoL).times.100. The average %
knockdown of ALK across all cell lines was 60% (range 21%-86%). The
average % knockdown of GAPDH was 75% (range 61%-95%).
ALK Protein and Phosphoprotein Detection
[0101] Neuroblastoma cell lines were grown in T75 flasks under standard
cell culturing conditions. For KELLY and SKNDZ lysates collected from the
siRNA knockdown experiments, cells were plated in T25s, transfected with
10 nM siRNA (as above) and collected at 24, 48 and 72 hours after
transfection. At 60-80% confluency (or the appropriate time point), the
cells were collected, pelleted and washed twice with ice cold PBS. Whole
cell lysates were extracted with 100 uL Cell Extraction buffer
(Invitrogen FNN011) containing protease inhibitors (Sigma, P-2714) and
PMSF, briefly sonicated and rotated for 1 hour at 4.degree. C. After a 30
minute centrifugation at 4.degree. C., the supernatant was removed and
protein quantification was performed using the Bradford method. Lysates
(50 ug for siRNA experiment and 100 ug for native cell lines) were
separated on 4-12% Bis-Tris gradient gels and transferred to PVDF
membranes. Membranes were then incubated and washed according to the Cell
Signaling Western protocol with 1:1000 ALK (Cell Signalling, #3333) and
Phospho-ALK (Cell Signalling, #3341) and 1:5000 actin (Santa Cruz,
sc-2352).
Results
Identification of Germline ALK Mutations
[0102] To identify the location of a hereditary neuroblastoma
predisposition gene, a genome-wide scan for linkage at .about.6000 single
nucleotide polymorphisms (SNPs) in 20 neuroblastoma families was
performed. Because of the rarity of the condition, the genome-wide scan
included pedigrees with varying degrees of confidence of actual
heritability. Eight families had three or more affected individuals of
close relation (high confidence), whereas 6 families consisted of only
two individuals of first-degree relation (moderate confidence), and 6
families also only consisted of two affected individuals, but of more
distant relationship (low confidence). A significant linkage signal at
chromosome 2p was discovered with a maximum nonparametric LOD score of
4.23 at rs1344063 in 18 of the families (two excluded due to insufficient
DNA).
[0103] This refined a region previously reported for one of the pedigrees
studied here (Longo et al. (2007) Hum. Hered., 63:205-11). By mapping
informative recombination events, a predisposition locus was defined at
chromosome bands 2p23-p24 delimited by SNPs rs1862110 and rs2008535 with
104 genes including the known neuroblastoma oncogene, MYCN (Schwab et al.
(1984) Nature, 308:288-91; Weiss, et al. (1997) EMBO J., 16:2985-2995),
and the ALK oncogene located 13.2 Mb centromeric. Despite previous work
showing that forced overexpression of MYCN to the murine neural crest
causes neuroblastoma (Weiss, et al. (1997) EMBO J., 16:2985-2995),
resequencing of the MYCN coding region and 18 Kb of surrounding genomic
DNA in probands from each linked family showed no disease-causal sequence
variations.
[0104] The anaplastic lymphoma kinase gene (ALK) was subsequently studied
because ALK had been previously identified as a potential oncogene in
neuroblastoma through somatically acquired amplification of the genomic
locus (Osajima-Hakomori et al. (2005) Am. J. Pathol., 167:213-22; George
et al. (2007) PLoS ONE 2:e255). In addition, oncogenic fusion proteins
leading to constitutive activation of the ALK kinase domain occur in many
human cancers including anaplastic large cell lymphoma (Morris et al.
(1994) Science, 263:1281-4), inflammatory myofibroblastic tumors (Griffin
et al. (1999) Cancer Res., 59:2776-80), squamous cell carcinomas (Jazii
et al. (2006) World J. Gastroenterol., 12:7104-12), and non-small cell
lung cancers (Soda et al. (2007) Nature, 448:561-6; Rikova et al. (2007)
Cell, 131:1190-203). ALK is a single chain receptor tyrosine kinase and a
member of the insulin receptor superfamily. Expression is normally
detected in developing central and peripheral nervous system. Further,
ALK is an orphan receptor as its ligand is not known. The normal function
of ALK is also not known. Indeed, a murine knockout shows no phenotype.
Mutations within ALK have not been previously described as mechanism of
oncogenicity.
[0105] Resequencing of the 29 ALK coding exons identified three separate
single base substitutions within the ALK tyrosine kinase domain in eight
of the probands screened (FIG. 1, Table 1). These DNA sequence
alterations were not present in single nucleotide polymorphism (dbSNP;
www.ncbi.nlm.nih.gov/projects/SNP/) or somatic mutation (COSMIC;
www.sanger.ac.uk/genetics/CGP/cosmic/) databases, and were not detected
in direct sequencing of the ALK tyrosine kinase domain in 218 normal
control alleles. Each substitution was subsequently shown to segregate
with the disease within each family (FIG. 1). The sequence variation in
FNB12 (R1275Q) appears to have been acquired de novo in the affected
father, and non-paternity was excluded by analysis of inheritance of
genotypes within this pedigree. There are several asymptomatic obligate
carriers identified (FNB2, FNB13, FNB32, FNB52, FNB56), suggesting that
the incomplete penetrance of this disease may be due to lack of the
acquisition of a second hit, or alternatively spontaneous regression
following malignant transformation in at least a subset of cases. Notable
is the very large multiplex family (FNB52) with discordance in twins and
multiple unaffected carriers that segregates a unique germline mutation
(G1128A).
TABLE-US-00002
TABLE 1
ALK mutations in neuroblastoma.
Probability
cDNA Activating
Mutation Variation Type/Frequency Region.sup.1 Mutation.sup.2
G1128A c.3383G > C Germline (1/8) P-Loop 0.95
R1192P c.3575G > C Germline (2/8) .beta.4 Strand 0.96
R1275Q c.3824G > A Germline (5/8) Activation 0.91
Somatic (8/24) Loop
D1091N c.3271G > A Somatic (1/24) N- 0.29
Terminal
M1166R c.3497T > G Somatic (1/24) C-Helix 0.79
I1171N c.3512T > A Somatic (2/24) C-Helix 0.85
F1174I c.3520T > A Somatic (1/24) End of 0.92
C-Helix
F1174L c.3522C > A Somatic (8/24) End of 0.96
C-Helix
F1245C c.3734T > G Somatic (1/24) Catalytic 0.94
Loop
F1245V c.3733T > G Somatic (1/24) Catalytic 0.91
Loop
I1250T c.3749T > C Somatic (1/24) Catalytic 0.87
Loop
.sup.1The region in which the codon alteration occurs is indicated. Note
that the D1091N is immediately adjacent to the tyrosine kinase domain.
.sup.2The probability that the amino acid alteration results in oncogenic
activation based on the methods of Torkamani and Schork (Torkamani et al.
(2007) Bioinformatics, 23: 2918-25).
[0106] An exemplary full-length ALK sequence is provided in GenBank
Accession No. NM.sub.--004304.3 (FIG. 9), although variants (e.g.,
natural allelic variants) of the ALK sequence are also encompassed by the
instant invention.
[0107] ALK sequence variations occurred only in the families with high or
moderate degrees of confidence for harboring a predisposing allele. Six
of the eight families with three or more affected individuals had ALK
missense alterations. The two families that did not have ALK sequence
alterations identified were each shown to harbor mutations in the
sympathicoadrenal lineage specific PHOX2B neurodevelopmental gene (Mosse
et al. (2004) Am. J. Hum. Genet., 75:727-30; Raabe et al. (2008) Oncogene
27:469-76). Two of the six families consisting of only two affected
individuals, but of first-degree relation, had ALK sequence variations.
Each of these families carried the R1275Q alteration, and in FNB12 it is
shown that the mutation arose de novo in the affected father, whereas in
FNB56 the alteration was inherited from an unaffected father (FIG. 1).
None of the six families with two distant relations affected with
neuroblastoma showed ALK alterations, suggesting that the occurrence of
an additional case of this relatively rare disease in an extended family
member was likely a chance occurrence. Since there are several families
who share identical mutations, it was determined if these families shared
a common haplotype around the ALK gene and showed that the affected
individuals with the same mutations did not share haplotypes, arguing
against a founder effect.
[0108] Because ALK functions as an oncogene in other human cancers, it was
predicted that the sequence variations discovered in the neuroblastoma
pedigrees would result in constitutive activation. Therefore, a support
vector machine-based statistical classifier was used to map the putative
mutations and determine the probability that they would act as drivers of
an oncogenic process (Torkamani et al. (2007) Bioinformatics, 23:2918-25;
Torkamani et al. (2008) Cancer Res., 68:1675-82). Each of the germline
alterations occurred at regions of the ALK kinase domain that have been
shown to be major targets for cancer driver mutations in other oncogenic
kinases (Table 1, FIG. 2). The R1275Q mutation was present in the
germline DNA of affected individuals from five pedigrees (FIG. 1), and
falls within the kinase activation loop in a region strongly associated
with activating mutations in many different protein kinases, such as BRAF
(Ikenoue et al. (2003) Cancer Res., 63:8132-7). This amino acid
substitution results in an electropositive residue being replaced by a
more electronegative one, possibly mimicking activating phosphorylation
events. The R1192P mutation occurred at the beginning of the f34 strand
of the kinase domain, and although it is predicted to be a driver
mutation with high confidence (Table 1) the mechanism for activation is
not yet clear (Torkamani et al. (2008) Cancer Res., 68:1675-82). The
G1128A was seen only in the large pedigree with affected individuals in a
single generation. The variation falls at the third glycine of the
glycine loop, and identical mutations of this glycine to alanine in BRAF
have been shown to increase kinase activity (Ikenoue et al. (2004) Cancer
Res., 64:3428-35).
Identification of Somatic ALK Mutations
[0109] Having shown that heritable mutations in the ALK tyrosine kinase
domain are associated with a highly penetrant predisposition to develop
neuroblastoma, it was determined if ALK activation might also be
somatically acquired. A representative set of 491 sporadically occurring
primary neuroblastoma samples acquired from children at the time of
diagnosis was examined on a 550K SNP-based microarray to assess for
genome-wide copy number alterations. A total of 112 cases (22.8%) showed
unbalanced gain of a large genomic region at 2p including the ALK locus
(partial trisomy), and an additional 16 cases (3.3%) showed high-level
focal amplification of ALK (FIG. 3). Each of the high-level
amplifications co-occurred with MYCN amplification and/or other regions
at 2p, except one case with an ALK amplicon only. The presence of
aberrant ALK copy number status (gain or amplification) was highly
associated with an aggressive clinical phenotype such as metastasis at
diagnosis (P<0.0001) and death from disease (P=0.0003).
[0110] Because of the association of ALK gain and amplification with
high-risk disease features, a subset of 167 tumor samples from high-risk
patients, and 27 human neuroblastoma-derived cell lines (all from
high-risk patients), was examined for sequence alterations in the ALK
tyrosine kinase domain. Fourteen of the 167 tumor (8.4%) and 10 out of 27
cell line (35.7%) samples showed single base substitutions consistent
with activating mutations (FIG. 2). Eight separate single base
substitutions were identified, with the R1275Q mutation being the only
mutation also seen in the germline DNA of the families studied. Again,
none of the sequence variations discovered here were in SNP databases or
were identified in the resequencing of the ALK tyrosine kinase domain in
109 control subjects (218 alleles).
[0111] Mutations were equally distributed between cases with and without
MYCN amplification. Only one case had a co-occurrence of an ALK mutation
(F 1174L) and genomic amplification of the ALK locus, and in this case
the mutated allele was amplified. Germline DNA was available for 9/14
patients with ALK mutations, and in one of these cases the sequence
alteration (I1250T) was also present in the germline suggesting a
hereditary predisposition that may or may not be de novo in this case.
[0112] Using the same statistical classifier employed for the germline
mutations, it was shown that all but one of the sequence variations
discovered in the tumor tissues were predicted to be activating mutations
(Table 1), and the one that shows a low probability (D1091N) was outside
of the core kinase domain. The vast majority of the somatically acquired
mutations fell into either the catalytic loop or C-helix kinase domains,
both frequent sites for oncogenic activating mutations (FIG. 2).
Catalytic loop mutants, especially I1250T, may promote oncogenesis by
altering substrate binding or, more likely, alter packing of the HRD and
DFG motifs towards an activated conformation (Kannan et al. (2005) J.
Mol. Biol., 351:956-72). The mutations observed in the ALK C-helix domain
occurred at positions within the kinase domain previously observed to be
mutated in other tumors. I1171N falls at an equivalent weakly oncogenic
position in MET (M1149T) (Jeffers et al. (1997) Proc. Natl. Acad. Sci.,
94:11445-50), and the M1166R, F11741 and F1174L mutants fall at
equivalent positions mutated in ErbB2 (D769, V777) and EGFR (D761, V769)
(Balak et al. (2006) Clin. Cancer Res., 12:6494-501; Lee et al. (2006)
Cancer Lett., 237:89-94; Lee et al. (2006) Clin. Cancer Res., 12:57-61).
Functional Consequences of ALK Mutations
[0113] Various genes are differentially expressed in human primary
neuroblastomas, with higher expression sometimes seen in the most
aggressive subset of tumors (Wang et al. (2006) Cancer Res., 66:6050-62).
It is shown herein ALK is highly expressed in all but one of 20 human
neuroblastoma-derived cell lines using quantitative RT-PCR. ALK
expression was higher in neuroblastoma cells compared to developing fetal
brain, and cell lines harboring ALK mutations (N=6) expressed the mRNA at
significantly higher copy number than ALK wild-type cell lines (N=14,
FIG. 4A). Analysis of protein lysates from a panel of neuroblastoma cell
lines showed constitutive phosphorylation of the tyrosine residue at
codon 1604 in each of the cell lines harboring mutations, with weak
phosphostaining in two wild-type cell lines (FIG. 4B).
[0114] To determine if ALK activation via mutation and/or amplification is
functionally relevant in models of high-risk neuroblastoma, and thus be a
tractable therapeutic target, the consequences of disrupting ALK
signaling via knockdown of messenger RNA was examined. siRNAs directed
against ALK (Dharmacon, Lafayette, Colo.) were transiently transfected
into 10 neuroblastoma cell lines and screened for inhibition of substrate
adherent growth. The knockdown of the mRNA and protein was demonstrated
in all lines studied, but showed differential effect on cellular
proliferation (FIGS. 5A-5L). Each of the cells harboring ALK mutation or
amplification showed profound inhibition of proliferation to ALK
knockdown. In addition, 2/6 of the ALK wild-type cell lines showed
significant inhibition of growth with ALK knockdown and each of these had
shown weak evidence for phosphorylation at tyrosine 1604 (FIG. 4b),
suggesting an alternative mechanism may have resulted in ALK kinase
activation in these two cell lines.
[0115] Currently, the frequency of ALK alterations in neuroblastoma are:
mutations in the TK domain: .about.10%, mutations in the extracellular
domain: .about.5%, and amplification: .about.8%. p-ALK is detectable in
20/134 (15%) of NBL tissue samples.
EXAMPLE 2
[0116] ALK is a tractable target for pharmacologic inhibition, but
sensitivity depends on mutation type. FIG. 6A is a graph of a dose
response curve and FIG. 6B is a graph of the % growth inhibition with
PF066 at 333 nM. FIG. 7 shows the expression of pALK, pAKT, pSTAT3, and
pMAPK3. For FIG. 6A, the human-derived neuroblastoma cell lines NB1643
(R1275Q), NB1 (ALK amplified), and NBSD (Fl 174L) were screened for
evidence of anti-tumor activity to ALK inhibitor PF-02341066 in vitro. A
quantitative assay to evaluate growth inhibition in a multi-well was used
in a parallel format to screen for cellular cytotoxicity. Inhibition of
substrate adherent growth during log-phase was then screened using the
96.times.6 RT-CES.TM. system (Real-Time Cell Electronic Sensing; ACEA
Biosciences; San Diego, Calif.) with cells plated in triplicate for each
assay, allowing for relatively high throughput and real-time assessment
of alterations in growth kinetics, assaying for potential cytostatic or
cytotoxic responses. The compound was studied at a minimum of 10 dose
levels to determine the IC.sub.50 values by concentration-response curves
across a 4-log dose range. For FIG. 6B, the proliferation of
neuroblastoma cell lines was measured after 72 hours of incubation with
PF234I066 (333 nM) in DMSO using the RT-CES.TM. system. Cell lines
displayed differential sensitivity depending on ALK status (p=0.01). Cell
lines with ALK mutations and one cell line with amplification of wild
type (WT) ALK were sensitive. R1275Q mutations were more sensitive than
F1174L mutations. No cell lines with normal copy number WT ALK showed
significant inhibition. Inhibition of growth %=100* (cell index
vehicle--cell index treatment)/cell index control. For FIG. 7, the
biochemical consequences of ALK activation and downstream signaling
pathways were studied in ALK-mutant lines. These experiments quantify
native and phosphorylated ALK, STAT3 and MAPK3 in ALK-mutated cell lines
treated with PF-02341066.
[0117] FIG. 8A provides the IC.sub.50 of various drugs on the
neuroblastoma cell line KELLY (F 1147L). FIG. 8B provides graphs of tumor
volume after weeks of administration of PF066. For FIG. 8A, the
human-derived NB cell line KELLY was screened for evidence of anti-tumor
activity to selective ALK inhibitors in vitro. A quantitative assay was
used to evaluate growth inhibition in a multi-well parallel format to
screen for cellular cytotoxicity. Inhibition of substrate adherent growth
during log-phase was screened for using the 96.times.6 RT-CESTm system
with cells plated in triplicate for each assay, allowing for relatively
high throughput and real-time assessment of alterations in growth
kinetics, assaying for potential cytostatic or cytotoxic responses. Each
available compound was studied at a minimum of 10 dose levels to
determine the IC.sub.50 values by concentration-response curves across a
4-log dose range. For FIG. 8B, an intervention design and initiate
therapy was used when tumors in mice are palpable at 200 mm.sup.3 as the
starting volume. A total of 20 mice were randomized to treatment with an
ALK inhibitor or vehicle, and serial measurements were performed using an
electronic caliper system. Tumor volume is expressed as the mean tumor
volume +/- standard error for groups of mice and tumor growth kinetics
over time and progression free survival were compared. ALK neuroblastoma
mutants can be mapped onto the cMet-PF'1066 crystal structure. ALK R1275Q
maps to c-Met R1227 which is not expected to destabilize the conformation
of the activation loop residues important for binding PF-1066. ALK F1174L
maps to c-Met F1124: This phenylalanine is highly conserved in ALK and
sits in a hydrophobic pocket necessary for correctly
positioning/stabilizing the conformation of residues 1222-1228. Mutation
of this residue is expected to significantly decrease PF-1066 binding.
Accordingly, this modeling is consistent with the data provided in FIG.
8B.
EXAMPLE 3
[0118] Neuroblastoma is a cancer of early childhood that arises from the
developing autonomic nervous system. It is the most common malignancy
diagnosed in the first year of life and shows a wide range of clinical
phenotypes with some patients having tumors that regress spontaneously
(D'Angio et al. (1971) Lancet 1:1046-1049), whereas the majority of
patients have aggressive metastatic disease (Maris et al. (2007) Lancet
369:2106-2120). Neuroblastoma remains an important clinical problem as it
continues to be a leading cause of childhood cancer mortality despite
dramatic escalations in dose-intensive chemoradiotherapy, and long-term
survivors experience significant treatment related morbidity (Oeffinger
et al. (2006) N. Engl. J. Med., 355:1572-1582; Hobbie et al. (2008)
Pediatr. Blood Cancer 51:679-683). To improve outcome and make
paradigm-shifting advances in this disease, it is necessary to discover
the key oncogenic drivers of the malignant process and exploit these
therapeutically.
[0119] The anaplastic lymphoma kinase (ALK) oncogene is a receptor
tyrosine kinase first identified after recurrent t(2;5) translocations in
anaplastic large cell lymphoma (ALCL) were shown to fuse the amino
terminus of nucleophosmin to a previously unidentified gene at 2p23
(Morris et al. (1994) Science 263:1281-1284). The ALK gene encodes a
1620-amino acid protein that undergoes post-translational N-linked
glycosylation, and expression is restricted to the developing central and
peripheral nervous system with a postulated role in regulation of
neuronal differentiation (Iwahara et al. (1997) Oncogene 14:439-449). It
has recently become clear that other human cancers in addition to ALCL
activate ALK signaling through unique oncogenic fusions of the ALK gene
with a variety of partners, including inflammatory myofibroblastic tumors
(Griffin et al. (1999) Cancer Res., 59:2776-2780), squamous cell
carcinomas (Jazii et al. (2006) World .1. Gastroenterol., 12:7104-7112)
and non-small-cell lung cancers (Soda et al. (2007) Nature 448:561-566;
Rikova et al. (2007) Cell 131:1190-1203). A recent phase 1 trial of the
dual MET/ALK kinase inhibitor PF-02341066 showed safety and significant
anti-tumor activity in patients with refractory solid tumors harboring an
ALK translocation (Kwak et al. (2009) J. Clin. Oncol., 27:15s (abstr
3509)).
[0120] Until recently, somatically acquired chromosomal translocation
events were the only known mechanism for constitutively activating the
ALK kinase. As explained herein, an unbiased linkage screen in familial
neuroblastoma was performed and activating mutations in the tyrosine
kinase domain of ALK were identified as the major cause of hereditary
disease. Additionally, somatically acquired genomic amplification of ALK
and mutations in the kinase domain as presumed oncogenic drivers in
sporadic (nonfamilial) disease were also identified (see herein as well
as Caren et al. (2008) Biochem. J., 416:153-9; Chen et al. (2008) Nature
455:971-974; George et al. (2008) Nature 455:975-978; Janoueix-Lerosey et
al. (2008) Nature 455:967-970). As explained herein, early data obtained
with the discovery of oncogenic mutations in this gene indicated that
siRNA and pharmacologic inhibition of ALK signaling in cells harboring a
mutation resulted in cytotoxicity, further indicating that ALK
mutation/amplification acts as a dominant oncogenic driver. Key to
impacting patient outcome with ALK-directed therapy was first to define
the cohort of subjects who are most likely to benefit from ALK
inhibition, and thus the prior mutation screen restricted to the
"high-risk" subset was extended to cover all neuroblastoma phenotypic
subsets. Second, preclinical experiments were performed to prove that the
lead pharmacologic ALK-inhibitor showed anti-tumor activity directly due
to on-target efficacy. The data presented here led directly to an ongoing
pediatric Phase 1/2 trial of the PF-02341066 inhibitor that has shown
safety and activity in ALK-activated adult solid malignancies.
Methods
Research Subjects and Samples
[0121] Neuroblastoma tumor samples were acquired from the Children's
Oncology Group Neuroblastoma Tumor Bank. The Children's Hospital of
Philadelphia Institutional Review Board approved this research.
DNA Sequencing
[0122] Bidirectional sequencing of the ALK coding sequence was performed
by Agencourt Biosciences on tumor DNA from 593 sporadic neuroblastomas
from the Children's Oncology Group (COG) tumor bank.
Tumor Copy Number Analysis
[0123] Tumor DNA from 591 sporadic neuroblastomas from the Children's
Oncology Group (COG) tumor bank were assayed on the Illumina Infinium.TM.
II HumanHap550 BeadChip as described above. DNA copy number for each
individual tumor was estimated using OverUnder (Attiyeh et al. (2009)
Genome Res., 19:276-83). Samples with a relative DNA copy
number.gtoreq.4.5 over the entire ALK locus were considered amplified,
whereas samples with a relative DNA copy number.gtoreq.2.3 were defined
as having low-level gain of ALK. Tumors harboring low-level gain
across.gtoreq.90% of chromosome 2 were defined as whole chromosome (WC)
gains; all other gains were considered regional. To assess the
statistical significance of recurrent regional gain/amplification on
chromosome 2, the STAC algorithm (Diskin et al. (2006) Genome Res.,
16:1149-1158) was applied using 1,000 random permutations of the regional
gains identified in 591 primary tumors. Both the frequency and footprint
statistics in STAC were evaluated, and an adjusted p-value.ltoreq.0.05
was considered statistically significant. Tumor Quantitative mRNA
Expression Tumor RNA from 96 sporadic neuroblastomas from the Children's
Oncology Group (COG) tumor bank was assayed on the Illumina Expression H6
v2. Cell Line Quantitative mRNA Expression Total RNA was isolated from
cell lines according to QIAGEN's miRNeasy protocol. Real-time PCR using
TaqMan.RTM. Gene Expression Assays was performed according to the
manufacturer's instructions (Applied Biosystems). All primer/probe sets
spanned exon boundaries to assure specificity for cDNA. Relative
expression of anaplastic lymphoma kinase (ALK) was determined by
normalization to the geomean of peptidyl-prolyl cis-trans isomerase B
(PPIB) and hypoxanthine phosphoribosyl-transferase (HPRT I) using a
standard curve method. All RTPCR experiments included a non-template
control and were done in triplicate. MET siRNA Knockdown in Neuroblastoma
Cell Lines This was performed in 4 cell lines using the 96-well RT-CES
microelectronic cell sensor system as described above.
DNA Constructs and Retrovirus Production
[0124] Four sequence variants were introduced into the full-length ALK
cDNA using site-directed mutagenesis (Origene Technologies, Rockville,
Md.). All mutations and overall cDNA integrity were confirmed by
sequencing of the entire ALK open reading frame. The mutant cDNAs, as
well as NPM-ALK and wild-type ALK cDNAs, were cloned into the pCMV-XLS
vector and subcloned into pIRES-EGFP. Infection of retinal pigment
epithelial cells that express telomerase (HTERT-RPE1) was performed as
follows: Phoenix.TM. Ampho cells (Oribigen--RVC-10001) were plated
.about.500,000 cells in a 6 well plate in DMEM media with 10% FBS, 1%
Pen/Strep, Gentamicin. Twenty-four hours after plating (.about.50%
confluent), Phoenix.TM. cells were transfected (Eugene) with retroviral
vector MigR1 containing the ALK constructs following the Eugene.RTM.
protocol (using 6:1 dilution of Fugene:plasmid DNA). HTERT-RPEI cells
were plated, .about.500,000 cells per well of 6 well plate, and then
harvested virus-containing media 48 hours post transfection. Media was
removed from Phoenix.TM. cells and filtered through 0.45 .mu.m syringe.
Growth media on HTERT-RPE1 cells was replaced with virus cocktail (2 ml
growth media, 1 ml filtered viral media, 4 .mu.g/ml Polybrene.RTM. (Santa
Cruz)) and incubated overnight. Viral media on HTERT-RPE1 cells was
replaced on day 5 with fresh growth media and incubated .about.48 hours.
HTERT-RPE1 cells then sorted in cell sorter for GFP positive cells.
In Vitro Tumor Growth Inhibition
[0125] In vitro activity of PF-02341066 (Pfizer) dissolved in dimethyl
sulfoxide (DMSO) was evaluated in 18 neuroblastoma cell lines using the
RT-CES system (ACEA Biosciences, San Diego, Calif.) that measures
electrical impedance of adherent cells, providing real-time
quantification of cell proliferation. Cell lines were plated at a range
of 5,000 to 30,000 cells per well depending on growth kinetics and drug
was added 24 hours later across a 4-log dose range (1-10,000 nM) in
triplicate. The IC50 was calculated from the cell index after 72 hours of
incubation using a variable slope (Graph pad Prism Version 5.0). Growth
inhibition at 333nM PF-02341066 was calculated using the formula: %
Inhibition=100*(Cell index control--cell index treatment)/Cell index
control. Due to non-comparable maximum growth inhibition depending on ALK
status, we analyzed growth inhibition at a single pharmacologically
relevant dose. To verify cell line integrity, all lines were routinely
genotyped (AmpFLSTR.RTM. Identifiler.RTM. kit; Applied Biosystems) and
mycoplasma tested.
In Vitro Protein and Phosphoprotein Detection
[0126] Each neuroblastoma cell line was cultured in ten T75 flasks under
standard cell culture conditions. At 70-80% confluence PF-02341066 was
added to cell culture medium to achieve a designated final concentration
at one of ten doses ranging from 0 nM to 10,000 nM. Cells were incubated
for 2 hours with drug, then collected, pelleted, and washed twice with
ice cold PBS. Whole cell lysates were then harvested, separated and
immunoblotted as described herein. The following antibodies were used
according to manufacturers' instructions: anti-ALK (1:1,000; Cell
Signaling, 3333), anti-phospho-ALK Tyr 1604 (1:1,000, Cell Signaling,
3341), anti-STAT3 (1:1,000; Cell Signaling, 9132), antiphospho-STAT3 Tyr
705 (1:1,000; Cell Signaling, 9145), anti-AKT (1:1,000; Cell Signaling,
9272), anti-phospho-AKT Ser 473 (1:1,000; Invitrogen, 44-621G),
anti-p44/42 MAPK (ERK1/2) (1:1,000; Cell Signaling, 4695),
anti-phospho-p44/42 MAPK (ERK 1/2) (1:1,000; Cell Signaling, 9101),
anti-actin (1:2,000; Santa Cruz, sc-1616).
In Vivo Tumor Growth Inhibition
[0127] CB17 scid female mice (Taconic Farms, N.Y.) were used to propagate
subcutaneously implanted neuroblastoma tumors. Tumor diameters were
measured twice per week using electronic calipers. Tumor volumes were
calculated using the spheroid formula, (.pi./6)*d.sup.3, where d
represents the mean diameter. Once tumor volume exceeded 200 mm.sup.3
mice were randomized (n=10 per arm) to receive PF-02341066 100mg/kg/dose
or vehicle (acidified water) daily by oral gavage for four weeks. Mice
were maintained under the protocols and conditions approved by our
institutional animal care and use committee. Mice were sacrificed when
tumors were greater than 1500 mm.sub.3.
In Vivo Protein and Phosphoprotein Detection
[0128] CB17 scid female mice (Taconic Farms, N.Y.) were used to propagate
subcutaneously implanted NB1643 neuroblastoma tumors. Once tumor volume
exceeded 300 mm.sup.3 mice were randomized (n=3 per arm) to receive
PF-02341066 100mg/kg/dose or vehicle (acidified water) daily by oral
gavage for 2 days. Mice were sacrificed 4 hours after the final dose to
harvest xenografts, which were immediately snap frozen in liquid
nitrogen. Frozen xenografts were pulverized and whole cell lysates were
extracted using 100 .mu.L extraction buffer (FNN011, Invitrogen)
containing protease inhibitor (P-2714, Sigma), phosphatase inhibitors
(P-5726, Sigma) and phenylmethyl sulphonyl fluoride. Lysates were
sonicated, and rotated for 1 hour at 4.degree. C. Following
centrifugation at 4.degree. C. for 30 minutes, the supernatant was
removed, and protein quantification was performed using the Bradford
method. Lysates (200 .mu.g) were separated on 4% -12% Bis-Tris gradient
gels and transferred to PVDF membranes which were immunoblotted according
to manufacturers' instructions: anti-ALK (1:1,000; Cell Signaling, 3333),
anti-phospho-ALK Tyr 1604 (1:1,000, Cell Signaling, 3341), and anti-actin
(1:5,000; Santa Cruz, sc-2352).
Homology Modeling
[0129] The wild-type ALK sequence alignment to c-Met was performed in the
PRIME suite within Maestro 8.5 (Schrodinger LLC, New York). Using the
full-length ALK sequence and the sequence derived from the crystal
structure of the kinase domain of c-Met with PF-02341066 (PDB
entry=2WGJ), the sequences were aligned automatically followed by manual
editing of gap areas. The final sequence alignment is shown in FIG. 15,
where the F1174 and R1275 mutation sites are highlighted in gray. PRIME
was then used to build a homology model of wild-type ALK with PF-02341066
bound using the c-Met/PF-02341066 crystal structure (2WGJ) as the
template. ALK mutations were modeled as point mutations in the resulting
wild-type ALK homology model.
Statistical Analysis
[0130] Associations of ALK mutation status and ALK amplification status
with accepted neuroblastoma risk factors were tested using a Fisher's
Exact Test (Table 2). Mixed-effects linear model was used to test tumor
volume over time between treatment and vehicle groups controlling for
tumor size at enrollment. The tumor size was transferred by logarithm
before data analysis. Survival analysis was performed using the Log-Rank
test with progression defined as tumor volume exceeding 1500 mm.sup.3 or
treatment related death. A P-value of 0.05 or less was considered to
indicate statistical significance. All data analyses were conducted with
the use of SAS.
Results
ALK Mutations are Restricted to the Tyrosine Kinase Domain and Occur in
all Phenotypic Subsets
[0131] Comprehensive re-sequencing of all 29 ALK coding exons and 500 base
pairs of flanking sequence was performed in 188 high-risk diagnostic
primary neuroblastoma tumors as part of the NBL-TARGET initiative
(Neuroblastoma-Therapeutically Applicable Research to Generate Effective
Treatments; target.cancer.gov/). The prior work presented the results
from 167 of these samples restricted to the kinase domain only and it was
sought to determine if non-kinase domain sequence alterations were
putatively pathogenic. In the extracellular domain, seven nonsynonymous
sequence variations were discovered and validated that were not reported
in any of the SNP databases (Table 2). Only one of these was somatic
(M770I), whereas five showed the same alteration in the germline DNA (one
sample did not have matched germline DNA available). Five nonsynonymous
sequence variations were found in the 3' untranslated portion of the
gene, but 3/3 with matched germline DNA showed the same sequence
variation in the constitutional DNA. Taken together, these data indicate
that somatically acquired sequenced variations outside of the ALK
tyrosine kinase domain are uncommon in neuroblastoma.
TABLE-US-00003
TABLE 2A
Nonsynonomous sequence variations within
the ALK tyrosine kinase domain (N = 594).
Number with
DNA sequence Protein coding alteration in
variation variation Frequency germline DNA
c.3452C > T T1151M 1 (2%) N/A
c.3497T > G M1166R 1 (2%) 0/1
c.3509T > G I1170S 1 (2%) 0/1
c.3512T > A I1171N 2 (5%) 0/2
c.3521T > G F1174C 1 (2%) 0/1
c.3520T > A F1174I 1 (2%) 0/1
c.3522C > A F1174L 7 (16%) 0/4
c.3586C > A L1196M 1 (2%) N/A
c.3599C > T A1200V 1 (2%) N/A
c.3610C > T L1204F 1 (2%) 1/1
c.3734T > G F1245C 2 (5%) 0/1
c.3733T > A F1245I 1 (2%) 0/1
c.3733T > G F1245V 2 (5%) 0/2
c.3749T > C I1250T 1 (2%) 1/1
c.3824G > A R1275Q 20 (47%) 0/17
TABLE-US-00004
TABLE 2B
Nonsynonomous sequence variations outside of
the ALK tyrosine kinase domain (N = 167).
Number with
DNA sequence Protein coding alteration in
variation variation Frequency germline DNA
c.106C > T P36S 1 (1%) 1/1
c.469C > T P157S 1 (1%) N/A
c.592G > A V198M 1 (1%) 1/1
c.776G > A R259H 1 (1%) 1/1
c.1918G > A G640R 1 (1%) 1/1
c.2310G > T M770I 1 (1%) 0/1
c.2978A > G D993G 1 (1%) 1/1
c.3271G > A D1091N 1 (1%) N/A
c.4219G > A E1407K 1 (1%) 1/1
c.4297_4299delGAG E1433del 1 (1%) N/A
c.4390C > G R1464G 1 (1%) N/A
c.4480G > A G1494R 1 (1%) N/A
c.4657G > C A1553P 1 (1%) 1/1
[0132] It was then sought to define the spectrum and frequency of somatic
ALK mutations across all neuroblastoma phenotypic subsets. A
representative set was identified of 594 primary neuroblastomas obtained
at diagnosis for sequence analysis restricted to eight amplicons covering
the entire tyrosine kinase domain. In total, non-synonymous sequence
variations were identified in 7.2% of samples (43/594), which were
grouped into four
hotspots within the kinase domain (Table 2). All
putative mutations in the ALK tyrosine kinase domain were not present in
the single nucleotide polymorphism database (dbSNP;
www.ncbi.nlm.nih.gov/projects/SNP/), and were not detected in direct
sequencing of the ALK tyrosine kinase domain in 218 normal control
alleles. The most prevalent mutation resulted in an arginine to glutamine
substitution at amino acid position 1275 (R1275Q) and occurred in 20/43
tumors with mutations (47%). This was also the most common germline
mutation discovered in hereditary neuroblastoma pedigrees, but was
acquired in all 17 sporadic cases here where matched germline DNA was
available. The second most common mutation resulted in a phenyalanine to
leucine substitution at amino acid position 1174 (F 1174L), occurring in
7/43 tumors harboring any sequence variation. In addition, the 1174
phenylalanine codon was mutated to isoleucine or cysteine in one case
each, so that this codon was altered in 21% of tumors with a tyrosine
kinase mutation. Of the 43 kinase domain mutations discovered in tumor
tissues, constitutional DNA was available for 32 patients, and the
majority were somatically acquired with 6.3% of cases (2/32) showing the
same alteration in the germline (L1204F and 11250T; Table 2).
ALK Amplification and Regional Gain of the ALK Locus are Associated with
Increased ALK Expression To define ALK allelic status, an overlapping set
of 591 primary neuroblastoma tumors was characterized on the Illumina
Human Hap550K SNP microarray. High-level amplification of ALK was
detected in 2.4% of tumors (Table 3), defined as copy number >4.5 of
the entire ALK gene relative to the chromosome 2 copy-number. Additional
tumor DNA was available for 10 of these cases, and none showed an ALK
mutation suggesting that mutation and gene amplification may be mutually
exclusive genomic events. All tumors with ALK amplification also harbored
MYCN amplification, but intervening sequence between these two genes
located 13 Mb apart often was not co-amplified (FIG. 10A). A subset of 96
of these tumors was also assayed using the 11lumina Expression Human6 v2
microarray. ALK amplification was significantly associated with ALK
overexpression (P<0.0001; FIG. 10B). In addition, regional gain of a
40MB region containing both MYCN and ALK was also associated with a
significant, but more modest, increase in ALK expression compared to both
whole chromosome gain (P=0.008) and normal copy number (P<0.0001; FIG.
10B).
TABLE-US-00005
TABLE 3
Frequency of ALK mutation and amplification in diagnostic primary
neuroblastomas.
Mutation Status (N = 593) P- Amplification Status (N = 591) P-
All Patients Mutation + Mutation - value* Amplification + Amplification -
value*
All Patients 867 43 (7%) 550 (93%) 14 577
Age 0.6871 0.6036
<365 days 283 (33%) 15 (35%) 179 (33%) 4 (29%) 169 (29%)
>365 days 580 (67%) 28 (65%) 370 (67%) 10 (71%) 405 971%)
Unknown 4 0 1 0 3
INSS Tumor 0.2541 0.0786
Stage
1 171 (20%) 7 (16%) 138 (25%) 0 (0%) 75 (13%)
2 119 (14%) 8 (19%) 79 (14%) 0 (0%) 48 (8%)
3 123 (14%) 6 (14%) 80 (15%) 2 (14%) 85 (15%)
4 390 (45%) 20 (47%) 220 (40%) 11 (79%) 321 (56%)
4S 56 (7%) 2 (4%) 31 (6%) 1 (7%) 42 (8%)
Unknown 8 0 2 0 6
MYCN Status 0.2452 <0.0001
Not Amplified 710 (83%) 33 (79%) 456 (84%) 2 (14%) 459 (81%)
Amplified 143 (17%) 9 (21%) 88 (16%) 12 (86%) 108 (19%)
Unknown 14 1 6 0 10
Shimada 0.7606 0.0502
Histopathology
Favorable 398 (49%) 22 (54%) 254 (49%) 2 (15%) 224 (41%)
Unfavorable 414 (51%) 19 (46%) 262 (51%) 11 (85%) 318 (59%)
Unknown 55 2 34 1 35
DNA ploidy 0.6653 0.0127
Hyperdiploid 517 (65%) 28 (68%) 355 (66%) 3 (27%) 331 (65%)
Diploid 275 (35%) 13 (32%) 181 (34%) 8 (73%) 176 (35%)
Unknown 75 2 14 3 71
COG Risk 0.5217 0.0009
Group
Low 327 (38%) 17 (40%) 237 (43%) 0 (0%) 151 (26%)
Intermediate 124 (15%) 7 (16%) 72 (14%) 0 (0%) 78 (14%)
High 406 (47%) 19 (44%) 237 (43%) 14 (100%) 342 (60%)
Unknown 10 0 4 0 6
*p-values from Fisher's Exact Test.
ALK Mutations Occur in all Phenotypic Subsets, but Amplification is
Restricted to the most Aggressive Cases Neuroblastoma is a diverse
neoplasm and can behave in either a very benign fashion, or an extremely
malignant one, based on a variety of clinical and biological factors
(Maris et al. (2007) Lancet 369:2106-2120). Three risk groups are
defined, with low-, intermediate- and high-risk cases having cure rates
of >97%, >90% and 40-50%, respectively (Maris et al. (2007) Lancet
369:2106-2120). These cure rates are achieved with no chemotherapy in the
low-risk group, moderate dose intensity chemotherapy in the
intermediate-risk patients, and highly intensive multimodal
chemoradiotherapy for the high-risk patients. Prior published studies had
focused on the ALK status in the high-risk group of patients, and here it
was determined if ALK aberrations occurred in the more benign subset of
cases as well. As shown in Table 3, ALK mutations occurred in all
phenotypic subsets, including all disease stages and risk groups.
Mutations were seen in the very benign state 1 low-risk tumors as well as
Stage 4S cases, that show spontaneous complete regression without
cytotoxic therapy (D'Angio et al. (1971) Lancet 1:1046-1049). In
contrast, ALK amplification events were restricted to the high-risk group
of patients only. Thus, the likelihood of an ALK aberration at diagnosis
in diagnostic high-risk neuroblastic tissues, where novel therapeutic
approaches are needed, is approximately 11.3%. ALK R1275Q, R1192P,
G1128A, and F1174L are Gain-of-Function Mutations that Induce
Differential Constitutive Kinase Activation To determine the functional
consequences of common germline and somatic mutations, human ALK cDNAs
were engineered harboring the three most common germline mutations
(R1275Q, R1192P, G1128A), and the F1174L mutation that was only seen in
tumor tissue. Next these cDNAs, as well as NPM-ALK and wild-type ALK,
were stably overexpressed in retinal pigment epithelial cells
immortalized with telomerase reverse transcriptase (hTERT-RPE 1) via
retroviral infection. hTERT-RPE1 cells were chosen for these experiments
because they are human neural crest-derived, as are neuroblastomas, and
do not express detectable levels of ALK by quantitative RT-PCR. FIG. 11
shows that native ALK was expressed in all transfectants, but
phosphorylation of the tyrosine 1604 residue, indicative of kinase
activation, was clearly different based on mutation type. Cells over
expressing the R1275Q and F1174L mutations, the two most common somatic
mutations observed here, showed the most intense phosphostaining. Cells
over expressing the G1128A mutant showed weak phosphostaining, only
observable on prolonged exposure similar to forced overexpression of
wild-type ALK. Without being bound by theory, this could provide an
explanation, at least in part, for the observation that this germline
mutation was unique to a previously reported large multiplex family that
was notable for having multiple unaffected carriers, with the lowest
tumor penetrance of all neuroblastoma families studied. Cytotoxicity to
Pharmacological ALK Inhibition in Vitro is Dependent upon ALK Genomic
Status It has been shown that mRNA knockdown of ALK in neuroblastoma cell
lines with mutation or amplification is cytotoxic, and thus ALK
inhibition might offer a tractable therapeutic target. In addition, it
has been shown herein that pharmacologic inhibition of ALK kinase
activity had an anti-proliferative effect in ALK mutated cell lines (see
also Chen et al. (2008) Nature 455:971-974; George et al. (2008) Nature
455:975-978; Janoueix-Lerosey et al. (2008) Nature 455:967-970). In order
to translate these findings to the clinic as quickly as possible, the
sensitivity of neuroblastoma was determined in in vitro and in vivo
models to PF-02341066, an ATP-competitive, orally bioavailable small
molecule inhibitor of ALK and MET, that has shown safety in early phase
clinical trials (Kwak et al. (2009) J. Clin. Oncol., 27:15s (abstr
3509)).
[0133] A panel of eighteen human neuroblastoma-derived cell lines, chosen
to be representative of ALK genomic status in primary tumors, was
utilized to determine the IC.sub.50 of PF-02341066 by
concentration-response curves across a 4-log dose range (1-10,000 nM).
Inhibition of substrate adherent growth was screened in a real-time
electrical impedance monitoring system (Yu et al. (2006) Anal. Chem.,
78:35-43; Atienza et al. (2006) J. Biomol. Screen 11:634-643). Cell lines
harboring an ALK aberration (mutations or amplification) displayed
significantly superior inhibition of growth than cell lines with
wild-type ALK status (P=0.0004, FIG. 12). Cell lines harboring the R1275Q
mutation or genomic amplification were more sensitive to this compound
than those harboring F1174L mutations (P =0.041).
[0134] To demonstrate that cytotoxicity with PF-02341066 is mediated
through ALK inhibition, it was shown that phospho-ALK correlated with ALK
genomic status (FIG. 13), and that none of seven neuroblastoma cell lines
studies, selected to be representative ALK genomic status, showed
phospho-MET expression. Furthermore, siRNA knockdown of MET in a panel of
4 cell lines representative of ALK status showed no significant growth
inhibition, as opposed to the significant inhibition seen with siRNA
mediated ALK knockdown. Finally, it was shown that cytotoxicity was
directly correlated with abrogation of phospho-ALK (see below, and FIG.
13).
Cytotoxicity in Vitro Correlates with Abrogation of Phospho-ALK and
Differential Inhibition of Downstream Signaling Pathways To correlate the
phenotypic effect seen in vitro to degree of inhibition of constitutive
kinase activation and to elucidate potential mechanisms underlying
differential sensitivity to PF-02341066, dose dependent inhibition of
phosphoprotein signaling was determined in three cell lines, selected to
be representative of ALK genomic status observed in patient samples. The
dose that first corresponded with inhibition of cell growth was
correlated to abrogation of ALK tyr1604 phosphorylation in all three-cell
lines (FIG. 13). Inhibition of proliferation and abrogation of
phospho-ALK occurred in a dose-dependent manner in the 33-100 nM range in
NB1 (WT amplification) and NB1643 (R1275Q), but did not occur in SH-SYSY
(F1174L) until 1000 nM, and these data were closely correlated to the in
vitro cytotoxicity assay results. Taken together, these data indicate
that the constitutive ALK activation via F 1174L mutation may be more
difficult to inhibit with PF-02341066.
[0135] In NB1 cells, abrogation of phospho-ALK occurred in parallel with
abrogation of phosphoprotein signaling in pathways known to be important
in lymphoma models of NPM-ALK mediated transformation: pSTAT3, pAKT, and
pERK (FIG. 13). By contrast, in NB 1643 cells, although the inhibition of
proliferation at 33 nM correlated to abrogation of phospho-ALK, similar
decreases in pSTAT3, pAKT, and pERK did not occur until higher micro
molar doses (FIG. 13). Without being bound by theory, the occurrence of
anti-tumor activity against NB 1643 at doses well below those where
pSTAT3, pAKT, and pERK were abrogated indicates this cell model may
mediate ALK oncogenicity through alternative signaling pathways.
Pharmacologic inhibition with PF-02341066 shows potent anti-tumor
activity in vivo It was then determined if pharmacologic ALK inhibition
resulted in anti-tumor activity in xenograft models of neuroblastoma. A
pharmacologically relevant dose of PF-02341066 at 100 mg/kg/day for 4
weeks was tested against serially passaged human neuroblastoma
xenografted in the flank of CB 17 immunodeficient mice (Zou et al. (2007)
Cancer Res., 67:4408-4417; Christensen et al. (2007) Mol. Cancer Ther.,
6:3314-3322). PF-03241066 caused regression of all NB1643 xenografts
(R1275Q) within three weeks, and complete regression was sustained over
the fourth week of dosing (P<0.0001, FIG. 14A). On target activity was
confirmed by demonstrating inhibition of ALK phosphorylation in NB 1643
xenograft protein lysates harvested after 2 days of administration of
PF-02341066 and 4 hours after last oral dose (FIG. 14A). Due to the range
of in vitro sensitivity against cell lines harboring F1174L mutations,
two such xenografts with differing sensitivity were tested. Treated
SHSY5Y xenografts resulted in significant tumor growth delay
(P<0.0001, FIG. 14B). In contrast, treatment of NBSD xenografts showed
no statistically significant difference in tumor volume over time between
treatment and control mice (P=0.3, FIG. 14C).
[0136] As cell line protein lysates and archival tumor specimens can
demonstrate phospho-ALK staining in the absence of genomic ALK
aberrations, in vivo activity of PF-02341066 was compared against two
xenografts with diploid copy number and wild type ALK sequence but with
differing levels of ALK expression and phospho-ALK activation. NB-EBc1
xenografts (previously shown to have weak phospho-ALK staining), treated
with drug demonstrated significant tumor growth delay (p<0.0001, FIG.
14D). By contrast, SKNAS xenografts with absent ALK expression and no
detectable phospho-ALK showed no tumor growth delay (P=0.87) and a
non-significant difference in days to reach a tumor volume of 1.5
cm.sup.3 (P=0.7) (FIG. 14E).
Homology Modeling Predicts a Structural Basis for Differential Activity
Against R1275Q and F1174L Mutations
[0137] A computational homology model of PF-02341066 bound to ALK was
derived from the available co-crystal structure of PF-02341066 bound to
the kinase domain of c-Met. Modeling was possible due to the high
sequence homology of the kinase domains in the areas near the
inhibitor-binding site. This model predicts that PF-02341066 binds very
similarly to both ALK and c-Met, with nearly all of the major protein
inhibitor interactions being conserved. In the PF-02341066 bound
conformation of wild-type ALK, residues D1270 through Y1278 of the kinase
activation loop form a bend. This bend creates one end of the
inhibitor-binding site and positions the side chain of Y1278 to enable a
key binding interaction with the fluorodichlorophenyl group of
PF-02341066 (FIG. 15 A, B).
[0138] The ALK homology model predicts that a R1275Q mutant is likely to
have the same PF-02341066 bound activation loop conformation as wild-type
ALK and c-Met. The side chain of R1275 points out towards solvent and
does not appear to make interactions critical for stabilizing the
PF-02341066 bound activation loop conformation (FIG. 15C). Therefore
substitution of arginine to glutamine is predicted to be accommodated on
the protein surface, and is not predicted to result in an activation loop
conformation that would significantly decrease key binding interactions
with PF-02341066.
[0139] In contrast, the F1174L mutation is predicted to result in an
activation loop conformation that significantly decreases binding of
PF-02341066. The side chain of F1174 is situated in a cluster of three
phenylalanines (F1174, F 1245, and F 1271) in attractive van der Waals
contact with each other. The three phenylalanines appear to form an
aromatic center that is part of a larger hydrophobic core. This
hydrophobic core is likely important for stabilizing the particular
activation loop conformation necessary to make key binding interactions
with PF-02341066 (FIG. 15 A, D). One of the three phenylalanines in the
hydrophobic core, F1271, is at the beginning of the activation loop and
lies within a conserved DFG (Aspartic acid, Phenylalanine, Glycine) amino
acid sequence. Conformational flipping of this conserved DFG sequences is
known to effect large changes in activation loop conformations in many
tyrosine kinases (Lu et al. (2009) Biochemistry 48:3600-3609; Hubbard,
S.R. (2002) Front. Biosci., 7:d330-340; Han et al. (2009) J. Biol. Chem.,
284:13193-13201).
[0140] As shown in FIG. 15D, a F1174L mutation is predicted to result in a
decrease in interactions within the aromatic center. This occurs because
the smaller size and non-planarity of leucine compared to phenylalanine
is predicted to result in a loss of contact with F1245. The loss of the
F1174L-F1245 interaction and accommodation of the non-planar leucine
likely destabilizes the aromatic center and hydrophobic core formed by
the three phenylalanines in wild type ALK. Destabilization of the
hydrophobic core could result in a flip of a flexible amino acid segment,
D1270-F1271-G1272, resulting in a large positional change in the
activation loop such that key binding interactions to PF-02341066 are
lost and inhibitory activity is reduced.
[0141] The recent discovery of germline and somatic gain of function
mutations in the receptor tyrosine kinase ALK provides a tractable
therapeutic target for new drug development in neuroblastoma. Here, the
frequency and spectrum of ALK gene mutations and amplification events was
determined in a representative series of diagnostic primary
neuroblastomas. The instant results demonstrate that ALK mutations are
detected in 7% of cases and are found primarily in the tyrosine kinase
domain. Other kinases such as EGFR (Lee et al. (2006) PLoS Med 3:e485),
KIT (Gari et al. (1999) Br. J. Haematol., 105:894-900), and FLT3
(Frohling et al. (2007) Cancer Cell 12:501-513) show activating mutations
in both the intra- and extra-cellular and juxta-membrane domains.
Accordingly, it is clear that sequence alteration outside the kinase
domain may be functionally relevant, but it is clear from the data
presented herein that the majority of ALK mutations occur in the kinase
domain.
[0142] High-level amplification of ALK was detected in another 2.4% of
tumors, so that about 10% of neuroblastomas have genomic evidence for ALK
activation at diagnosis. Unlike sequence variation mutations, high-level
ALK amplification was restricted to the high-risk group of tumors with
concomitant MYCN amplification.
[0143] These data indicate that in the setting of genomic instability, ALK
can be a target for amplification events that presumably lead to pathway
activation due to homodimerization of overexpressed ALK protein. Notably,
19% of tumors show unbalanced gain of 2p including the ALK locus. Some of
these are focal, suggesting a tandem duplication event targeting the ALK
locus, but the majority of these are very large, often involving the
majority of the short arm. The unbalanced gains in 2p may correlate with
pathway activation and/or sensitivity to targeted interruption of ALK
signaling.
[0144] The two most commonly observed mutations resulted in robust
constitutive phosphorylation of the ALK kinase, whereas the rare germline
mutation G1128A, which has not been observed somatically, resulted in
only weak activation, similar to the amount seen with forced
overexpression of wild-type protein. While these data are
semiquantitative, the magnitude of difference is clear and consistent
with the observation that heritable G1128A mutations resulted in low
tumor penetrance, compared to the families with R1275Q germline
mutations, each showing near complete tumor penetrance in at risk
carriers. The hTERT-rRPE 1 assay provides complimentary information to
forced overexpression in other systems, such as BAF3 (George et al.
(2008) Nature 455:975-978) or NIH-3T3 cells (Janoueix-Lerosey et al.
(2008) Nature 455:967-970), but the instant system offers advantages for
further functional analysis of mutations as they are discovered to
determine their potential as an oncogenic driver in an appropriate
cellular context. Cellular context is important and the use of this
system to understand the functional consequences of all sequence
variations identified may be used to dissect the oncogenic potency of the
various mutations discovered.
[0145] The data clearly demonstrate that cytotoxicity to PF-02341066 is
highly associated with ALK genomic status and evidence for constitutive
activation. It is also evident that some neuroblastomas may somatically
activate ALK signaling in the absence of mutation or amplification.
[0146] PF-02341066 has already demonstrated safety and tolerability in
humans, as well as dramatic reductions in tumor volumes and disease
stabilization for non-small cell lung cancers with activated ALK via
translocation events. This drug is robustly cytotoxic in vitro and in
vivo in cells with the most common mutation (R1275Q) and in wild-type
cells with high-level ALK amplification (p <0.0004), and it is shown
herein that this is not an effect of c-Met inhibition. Fl 174L models
also show growth inhibition with PF-02341066, though not nearly as
potently; and there are models without evidence for ALK mutation, but
with constitutive activation that show growth inhibition, suggesting that
several subsets of patients may benefit from ALK inhibition therapy. It
is evident that phospho-ALK is an appropriate surrogate biomarker of
response and that abrogation of phospho-ALK can be highly correlated with
response to pharmacologic inhibition.
[0147] In NPM-ALK driven lymphoma models, it has been shown that several
canonical signaling pathways are activated, including STAT3, AKT/PI3K,
and RAS/ERK, thus influencing cell proliferation and survival (Zamo et
al. (2002) Oncogene 21:1038-1047; Chiarle et al. (2005) Nat. Med.,
11:623-629; Lim et al.
[0148] (2009) Blood 114:1585-1595). However, the situation appears to be
more complex in neuroblastoma. The NB1 model with wild type, amplified
ALK, shows constitutive activation of each of these pathways, with
dose-dependant abrogation of signaling paralleling diminution of
phosphorylated ALK and cytotoxicity. However, the NB1643 cells harboring
an R1275Q mutation are equally sensitive to PF-02341066, show the same
pattern of diminution of phospho-ALK staining, but do not likewise
abolish phosphorylated proteins in the STAT3, AKT/PI3K, and RAS/ERK until
much higher doses. SY5Y cells, which are relatively resistant to
PF-02341066, also do not abolish STAT3, AKT/PI3K, and RAS/ERK signaling
even at the higher dose levels where cytotoxicity (and diminished
phosphorylated ALK) was seen. Without being bound by theory, these
data--taken together--indicate that ALK mutations may exert their
oncogenic effect through other pathways.
[0149] The data presented herein show that mutations in ALK are present
across all neuroblastoma disease subsets, both benign and malignant
forms, consistent with acquired ALK activation being an early event in
tumorigenesis. ALK amplification, however, is strongly associated with
the high-risk subset (P<0.001) and MYCN amplification (P<0.001), so
that approximately 11% of all newly diagnosed high-risk neuroblastoma
patients harbor genetic evidence for ALK activation and can be expected
to potentially benefit from ALK inhibition therapy. In the instant
dataset, mutations and amplifications of ALK are mutually exclusive,
suggesting these modes of genomic dysregulation do not co-occur in
sporadic neuroblastoma. Mutations in ALK are significantly more frequent
in human neuroblastoma-derived cell lines. Without being bound by theory,
this may occur through selection of rare clones that are present in
diagnostic tissues and emerge during therapy, as has been shown in
chronic myeloid leukemias harboring a BCR-ABL gene translocation,
mutation or amplification (Gorre et al. (2001) Science 293:876-880).
[0150] As the crystal structure for the ALK kinase domain has not been
solved, in silico techniques were used to explore the observed
differentially cytotoxicity of PF-02341066 against the two most common
mutations observed in patient samples.
[0151] Structural modeling predicted that the phenylalanine to leucine
substitution at codon 1174 (F1174L) results in destabilization of the
PF-02341066 binding site, whereas the R1275Q mutation has no predicted
effect on this small molecule binding and thus competing with ATP.
[0152] Taken together, these data provide strong rationale for the
clinical use of PF-02341066 for patients with neuroblastoma. This
represents the first therapy for neuroblastoma specifically developed for
a mutated oncogenic driver.
[0153] EXAMPLE 4 Table 4 provides the frequency and spectrum of ALK
mutation in diagnostic primary neuroblastomas (n=1148), as described
hereinabove. Table 5 provides the frequency of mutations in various
subsets of the population based on risk, as described hereinabove.
TABLE-US-00006
TABLE 4
Frequency and spectrum of ALK mutations
in diagnostic primary neuroblastomas.
All Patients Mutation+
All Patients 1148 84 (7.3%)
Age
<365 days 438 (38%) 29 (6.6%)
>365 days 709 (62%) 55 (7.8%)
>3650 days 36 (3%) 6 (17%)
INSS Tumor Stage
1 288 (25%) 14 (4.9%)
2 211 (18%) 21 (10%)
3 172 (15%) 10 (5.8%)
4 401 (35%) 36 (9%)
4S 76 (7%) 3 (4%)
MYCN Status
Not Amplified 984 (86%) 65 (6.6%)
Amplified 156 (14%) 18 (11.5%)
Shimada
Histopathology
Favorable 629 (55%) 43 (6.8%)
Unfavorable 466 (41%) 37 (7.9%)
DNA Ploidy
Diploid 377 (33%) 31 (8.2%)
Hyperdiploid 729 (64%) 51 (7%)
COG Risk Group
Low 548 (48%) 35 (6.4%)
Intermediate 203 (18%) 14 (6.9%)
High 397 (34%) 35 (8.8%)
TABLE-US-00007
TABLE 5
Frequency of mutations in low risk, intermediate risk, and high risk
samples.
SAMPLE TOTAL
SET MUTATIONS R1275 F1174 F1245
LOW RISK 35/548 (6.4%) 16/36 (44%) 7/23 (30%) 6/11 (55%)
(N = 548)
INT RISK 14/203 (6.9%) 6/36 (17%) 6/23 (26%) 1/11 (10%)
(N = 203)
HIGH RISK 35/397 (8.8%) 14/36 (39%) 10/23 (43%) 4/11 (36%)
(N = 397)
ALL 84/1148 (7.3%) 36/84 (43%) 23/84 (27%) 11/84 (13%)
TUMORS
(N = 1148)
EXAMPLE 5
[0154] The co-administration of ALK antibodies with a tyrosine kinase
inhibitor induces cell death in cells that were less sensitive to the
tyrosine kinase inhibitor alone. FIG. 16 shows the co-administration of
PF-1066 with mAb 30 and 49 were significantly more effective than PF-1066
alone or mAb 30 and 49 alone against SH-Sy5Y (F1174L) cells. mAb 30 and
49 are described in Moog-Lutz et al. (J. Biol. Chem., (2005)
280:26039-26048).
EXAMPLE 6
[0155] Anaplastic Lymphoma Kinase (ALK) was originally identified in an
oncogenic fusion protein expressed in anaplastic large cell lymphoma
(ALCL) as a result of a chromosomal translocation (Morris et al. (1994)
Science 263:1281-4). This fusion links the intracellular region of the
ALK receptor tyrosine kinase (RTK) to the N-terminal portion of
nucleophosmin (NPM), leading to constitutive kinase activation in an
NPM-ALK fusion (Morris et al. (1994) Science 263:1281-4). Other oncogenic
ALK fusions have since been identified in several human cancers,
including non-small cell lung cancer (NSCLC), squamous cell carcinoma,
and inflammatory myofibroblastic tumors (Soda et al. (2007) Nature
448:561-6; Rikova et al. (2007) Cell 131:1190-203; Jazii et al. (2006)
World J. Gastroenterol., 12:7104-12; Griffin et al. (1999) Cancer Res.,
59:2776-80). The full-length ALK RTK has also been linked to
neuroblastoma, a pediatric cancer of the sympathetic nervous system that
accounts for 10% of childhood cancer mortality (Miyake et al. (2002)
Oncogene 21:5823-34; Maris et al. (2010) N. Engl. J. Med., 362:2202-11;
Smith et al. (2010) J. Clin. Oncol., 28:2625-34). Intact ALK is expressed
in the majority of neuroblastomas, suggesting a role in autonomic nerve
development, and the ALK gene is amplified in 2-3% of cases (Lamant et
al. (2000) Am. J. Pathol., 156:171 1-21; Passoni et al. (2009) Cancer
Res., 69:7338-46; Wang et al. (2006) Cancer Res., 66,6050-62; George et
al. (2007) PLoS One 2:e255). Herein, activating mutations within the
tyrosine kinase domain of full-length ALK were identified as the major
cause of familial neuroblastoma and were also shown to arise somatically
in up to 10% of sporadic neuroblastoma cases (see also Janoueix-Lerosey
et al. (2008) Nature 455:967-70; Mosse et al. (2008) Nature 455:930-5).
Amplification and mutation of ALK lead to its constitutive
autophosphorylation and activation, and may be associated with a more
aggressive clinical course (see also Passoni et al. (2009) Cancer Res.,
69:7338-46; George et al.
[0156] (2007) PLoS One 2:e255; Mosse et al. (2008) Nature 455:930-5;
Osajima-Hakomori et al. (2005) Am. J. Pathol., 167:213-22; De Brouwer et
al. (2010) Clin. Cancer Res., 16:4353-62).
[0157] Cure rates among children with high-risk neuroblastoma have shown
only modest improvement, despite dramatic escalations in the intensity of
therapy provided. Survivors of modern high-risk neuroblastoma therapy are
at risk for major morbidities, many of which can be life-threatening
(Hobbie et al. (2008) Pediatr. Blood Cancer 51:679-83; Oeffinger et al.
(2006) N. Engl. J. Med., 355:1572-82). It is therefore clear that new
approaches are required for treating neuroblastoma.
Materials and Methods
Cell Culture and Reagents
[0158] All cell lines were maintained in a 5% CO.sub.2 incubator at
37.degree. C. in RPMI (Invitrogen) supplemented with 10% fetal calf
serum, L-glutamine, penicillin/streptomycin, and gentamicin (Invitrogen).
Mouse monoclonal IgG1 antibodies 14, 30, 46 and 49 were generated to the
extracellular domain of human ALK as previously described (Moog-Lutz et
al. (2005) J. Biol. Chem., 280:26039-48). Crizotinib was obtained from
Pfizer and diluted in dimethylsulfoxide (DMSO; Sigma) for use in cell
culture. Murine IgG1 (Sigma-Aldrich) and DMSO were used respectively as
negative controls.
Quantitative mRNA Expression
[0159] RNA from primary diagnostic tumor specimens of 229 children with
neuroblastoma was obtained and analyzed using Affymetrix Human Exon Array
(HuEx). HuEx arrays were normalized using quantile normalization and
summarized using robust multichip average (RMA) using Affymetrix Power
Tools software package version 1.12. ALK expression levels were obtained
by averaging the core unique probesets for the ALK transcript (Transcript
ID: 2546409). Data were analyzed for significance among patients
diagnosed with low risk disease (stage 1 and 2 neuroblastoma, n =24),
high risk metastatic MYCN non-amplified neuroblastoma (>18 months of
age at diagnosis, n =141), and high risk MYCN amplified neuroblastoma
(n=64). The overall p-value among the groups was carried out using
likelihood ratio chi-squared tests in the context of a general linear
model. Differences between two subgroups were assessed using the Wald
test. The analyses were performed using the R statistical package (R
version 12.1).
Immunohisiochemistry
[0160] Cases were selected from a review of neuroblastic tumors
accessioned to the Pathology Department of the Children's Hospital of
Philadelphia from 1987 to 2004. Selection of specimens and construction
of the tissue micro-array (TMA) followed approval by the Children's
Hospital of Philadelphia Institutional Review Board. All tumors were
reviewed by a pediatric pathologist for adequacy, and classified
pathologically for diagnosis, grade, Shimada histology and
mitotic-karyorrhectic index using International Neuroblastoma Pathology
Classification criteria. The resultant TMA comprised two paraffin blocks
and contained tumor cores from 126 patients, including 117 neuroblastomas
and 9 nodular ganglioneuroblastomas. 0.6 mm cores of representative tumor
tissue from each case were used to construct the tissue microarray blocks
using a manual arrayer (Beecher Instruments). MYCN amplification status
and stage (International Neuroblastoma Staging System, INSS) were
obtained by tumor registry review. Staining of the TMA was conducted with
prediluted anti-ALK-1 (Ventana Medical Systems), using pressure cooker
antigen retrieval, overnight incubation, and avidin-biotin complex
conjugation. Percent positivity of the neuroblasts within the cores was
assessed, and intensity of staining was graded on a scale of 1-3 (weak,
moderate, strong). An ALK staining score was calculated as the product of
percentage of neuroblasts stained and grade of intensity.
Immunofluorescence
[0161] Cell lines were plated on Lab Tek II Chamber Slides (Thermo
Scientific).
[0162] After overnight incubation at 37.degree. C., slides were
transferred to ice and cells were washed three times with ice-cold PBS
before blocking for 20 minutes with 10% BSA in PBS. Cells were next
incubated for 60 minutes on a rocker table with ALK antibody mAb14 at a
1:100 dilution in 1.5% BSA/PBS. After three 5 minutes washes, cells were
incubated for 45 minutes in the dark with Rhodamine-conjugated goat
anti-mouse secondary antibody (Jackson) then washed 3.times.5 minutes and
coverslipped with mounting media containing DAPI stain (Santa Cruz) for
evaluation with a fluorescence microscope.
Flow Cytometry with ALK Antibodies
[0163] Cells were kept ice-cold during staining to minimize receptor
endocytosis. Cells that had achieved 70-80% confluency were harvested and
washed twice with ice-cold 1% FCS/PBS buffer containing 2 mM EDTA
(Invitrogen), then ALK antibody mAb14 was added as a staining antibody at
a final concentration of 10 .mu.g/ml. Cells were incubated 20 minutes on
ice then washed twice. Donkey anti-mouse IgG PE (eBioscience) was then
added at a concentration of 2.5 .mu.g/ml and cells were incubated for 20
minutes on ice in the dark and washed. In some experiments, cells were
grown in T25 flasks until 70-80% confluency and crizotinib was added (or
DMSO as a negative control) and cells harvested at various subsequent
timepoints for flow cytometry. In some experiments, staining was
conducted with both the mAb14 and mAb46 which binds a distinct epitope
from mAb14. Cells were then analyzed on an LSR II Flow Cytometer (BD
Biosciences). All results shown are representative of at least 3
independent experiments.
Growth Inhibition
[0164] The Real-Time Cell Electronic Sensing (RT-CES) system (ACEA
Biosciences, San Diego, Calif.) was used to measure the in vitro effect
of the ALK antibodies mAb30 and mAb49 alone or in combination with the
tyrosine kinase inhibitor crizotinib on neuroblastoma cell line growth.
Cell lines were plated in triplicate in 96-well plates. Antibody and/or
drug were first added 24 hours after plating, and antibody treatment was
continued for four additional days. Growth inhibition was calculated as:
100*(1-(cell index treatment/cell index control)). All cell lines were
routinely mycoplasma tested and genotyped using the AmpFLSTR Identifiler
kit (Applied Biosystems). All RT-CES experiments were conducted a minimum
of three times, and results quoted as mean .+-. standard deviation. For
statistical analysis of results, linear mixed effect models were fitted
to examine time and treatment effects. To account for nonlinearity, time
by treatment and time square by treatment interaction terms were included
in the models. F tests were used to examine the difference of the
progression of cell index over time between each individual treatment and
the combination treatment.
Calculation of IC.sub.50
[0165] The RT-CES system was used to measure growth of cell lines plated
in a 5-log dose range of 1-10,000 nM crizotinib alone or in combination
with 10 .mu.g/ml ALK mAb30 and mAb49. GraphPad Prism Version 5.0 was used
to calculate the IC.sub.50 from the RT-CES-generated cell index data
using the log(inhibitor) vs. response--variable slope equation.
Western Blots
[0166] Cells were grown in 10 cm dishes until 70-80% confluency, at which
point 1000 nM crizotinib, 10 .mu.g/ml ALK antibody, both agents, or the
relevant negative controls were added. After 72 hours of incubation,
flasks were transferred to ice, washed with ice cold PBS, and cells
scraped into ice-cold PBS. After pelleting, whole cell lysates were
harvested and immunoblotted with either antibodies against ALK (1:1,000;
Cell Signaling, 3333), phospho-ALK Tyr 1604 (1:1,000, Cell Signaling,
3341), or actin (1:2000; Santa Cruz, sc-1616). Results shown are
representative of two independent experiments.
Propidium Iodide Staining
[0167] SY5Y cells were plated in 6-well plates at 2.times.105 cells per
well. After 24 hours, 1000 nM crizotinib, 10 .mu.g/ml ALK antibody, both
agents, or the appropriate negative controls, were added. Antibody
treatment was continued for four additional days. Cells were then
harvested and washed twice. Ice-cold ethanol was added while vortexing,
and cells were allowed to stand for 20 minutes at 4.degree. C. Cells were
again washed twice and then resuspended in phosphate-citric acid buffer
and allowed to stand at room temperature for 5 minutes. After washing,
cells were resuspended in a 1% FBS solution containing RNAseA (Roche) and
50 .mu.g/ml propidium iodide (Sigma-Aldrich) and incubated at room
temperature in the dark for 30 minutes. Cells were then analyzed on an
LSR II flow cytometer.
Antibody-Dependent Cell-Mediated Cytotoxicity Assay
[0168] The Cyto Tox 96 Non-Radioactive Cytotoxicity Assay (Promega) was
used to assess antibody-dependent cell mediated cytotoxicity. Normal
donor peripheral blood mononuclear cells were used as effectors and
plated in 10 cm dishes in complete RPMI for 2 hours at 37.degree. C. to
allow monocytes to adhere. Non-adherent peripheral blood lymphocytes were
then replated in complete RPMI containing 1000 IU/ml rhIL-2 (Chiron) and
incubated overnight. The following day, effector cells were collected and
washed. Target NB1 or SY5Y cells that had been grown on T75 flasks until
70-80% confluency were also harvested and washed. In some experiments,
SY5Y cells were pre-incubated for 48 hours in crizotinib before being
used as target cells in the ADCC. Effector and target cells were then
plated in quadruplicate at effector:target ratios of 50:1, 25:1, and 10:1
and experimental wells treated with 1 .mu.g/ml ALK mAb30 and mAb49.
Control wells were plated according to the manufacturer's specifications.
After a 4-hour incubation at 37.degree. C., cell viability was assessed
by an enzymatic assay allowing for the quantification of lactate
dehydrogenase which is released upon cell lysis. The % cytotoxicity was
calculated as follows: [(Experimental-Effector Spontaneous-Target
Spontaneous)/(Target Maximum-Target Spontaneous)].times.100. To ensure
specificity of the ALK antibody, separate experiments were conducted
comparing untreated wells to treatment with 1 .mu.g/ml murine IgG1. No
difference was detected between untreated (mean % cytotoxicity=3.1%,
SD=0.3%) and IgG1-treated wells (mean % cytotoxicity=0.64%, SD=0.28%;
p=0.8822). Results shown are representative of three independent
experiments, and quoted as mean .+-.standard deviation.
Results
ALK is Widely Expressed in Neuroblastoma Tumors and Cell Lines
[0169] Successful immunotherapy requires the targeted antigen to be
expressed selectively in tumors, but not in normal tissue. Moreover, the
targeted antigen must be expressed on the majority of tumors for
immunotherapy to be relevant to a large proportion of patients, and
expression levels should ideally be related directly to measures of
disease severity. Since intact ALK is normally found only in the
developing embryonic and neonatal brain (Iwahara et al. (1997) Oncogene
14:439-49), it could be a valuable target for immunotherapy if expressed
in the majority of tumors. To assess ALK expression in primary patient
tumors, data from Wang et al. (Cancer Res. (2006) 66:6050-62) as well as
the TARGET initiative (Therapeutically Applicable Research to Generate
Effective Treatments: target.cancer.gov/). As shown in FIG. 17A, ALK mRNA
expression is seen in tumors from patients with clinically aggressive
disease, especially in those with high-risk metastatic disease and/or
MYCN amplification [p=5.06E-05 for high-risk MYCN amplified (HRA) vs.
low-risk (LR), p=0.0022 for HRA vs. high-risk MYCN non-amplified (HRN),
p=0.0211 for HRN vs. LR]. To verify ALK expression at the protein level,
a tissue microarray of diagnostic neuroblastomas and
ganglio-neuroblastomas was analyzed. Samples from 126 patients were
stained for native ALK expression with anti-ALK-1 and graded the
intensity of ALK staining on a scale of 1-3 (representative samples shown
in FIG. 17B) and percent positivity. Among the samples analyzed, 109
(86.5%) were ALK-positive, with 75 samples (59.5%) having either moderate
(grade 2) or strong (grade 3) staining. Moreover, as shown in FIG. 17C,
ALK expression was significantly stronger in patients with INSS stage 4
(p=0.0108; top panel) or amplified MYCN (p=0.0065; bottom panel). These
data indicate that ALK is expressed in the vast majority of neuroblastoma
tumors, and that expression levels are higher in those patients with the
worst prognosis.
[0170] Since ALK expression at the cell surface is a prerequisite for
ALK-targeted immunotherapy to be effective, flow cytometry was used to
quantify cell surface ALK levels in a panel of human
neuroblastoma-derived cell lines. As shown in FIGS. 17D and 17E, ALK was
abundant on the cell surface of cell lines expressing either wild-type
ALK (NB1, EBc1, and IMR5) or mutated ALK (1643, R1275Q; SY5Y, F1174L;
Kelly, F1174L) when compared to the negative control SKNAS line that has
been shown to have no detectable ALK expression (see above and Mosse et
al. (2008) Nature 455:930-5). As also shown in FIG. 17E, cell surface ALK
expression corresponded closely with relative ALK mRNA expression as
measured by quantitative RT-PCR. To further analyze cell surface ALK
expression, immunofluorescence staining of the neuroblastoma cell lines
NB1 and SY5Y was conducted (FIG. 17F). Consistent with the results of
flow cytometry, ALK was detected at the plasma membrane of both cell
lines. These data indicate widespread expression and cell surface
localization of full-length ALK in neuroblastoma.
An ALK Antibody Induces Growth Inhibition and Cytotoxicity
[0171] Having established that extracellular ALK antigens are accessible
at the surface of neuroblastoma cell lines, it was then determined
whether an antagonistic ALK monoclonal antibody identified by Moog-Lutz
et al. (J. Biol. Chem. (2005) 280:26039-48) can inhibit growth of a
neuroblastoma cell line driven by expression of activated ALK. First SY5Y
cells (which express F1174L-mutated ALK) were treated with a 3-log dose
range of a mixture of two ALK antibodies (mAb30 and mAb49), and growth
was measured over 152 hours relative to control-treated cells (FIG. 18A).
Although SY5Y cells express high levels of phospho-ALK, they are
relatively insensitive to growth inhibition by crizotinib. However,
treatment with the ALK antibody resulted in significant dose-dependent
growth inhibition as compared to cells treated with control
immunoglobulin. To assess whether this effect is general, a panel of
well-characterized neuroblastoma cell line models harboring wild-type ALK
(IMR5), mutated ALK (1643 and SY5Y), amplified ALK (NB1), or undetectable
ALK (SKNAS) were treated with a fixed concentration of mAb30 and mAb49
(10 .mu.g/ml total). As shown in FIG. 18B, there was a direct correlation
between ALK expression levels and antibody-induced cytotoxicity, with the
ALK amplified line NB1 showing the greatest sensitivity to antibody
treatment, and the ALK-negative cell line SKNAS showing no growth
inhibition. As an additional negative control, retinal pigmented
epithelial cells (RPE-1)--a non-neuroblastoma, ALK-negative, neural
crest-derived cell line--was treated with 10 .mu.g/ml ALK antibody or
murine immunoglobulin as above, and saw no growth inhibition (FIG. 18C).
Importantly, given their variable sensitivity to ALK-targeted TKIs, cell
lines expressing mutated ALK (1643 and SY5Y) showed significant degrees
of antibody-induced cytotoxicity.
[0172] Immune cell-mediated ADCC has been shown to be important for the
mechanism of action of the GD2 antibody in neuroblastoma, and this effect
is substantially enhanced in the presence of interleukin-2 (IL-2) (Hank
et al. (1990) Cancer Res., 50:5234-9). To explore whether an ALK antibody
is also capable of inducing an immune-mediated anti-tumor response in
neuroblastoma, in vitro ADCC assays were conducted in which normal donor
peripheral blood lymphocytes (PBL) were used as effectors, and
neuroblastoma cell lines used as targets. Lymphocytes pre-incubated with
IL-2 induced substantially higher levels of cytotoxicity in NB 1 cells
treated with anti-ALK mAb30 and mAb49 than in untreated cells (FIG. 18D,
left panel). F1174L-expressing SY5Y cells also showed cytotoxicity in
this assay (FIG. 18D, middle panel), although less than seen for NB1
cells, possibly because of the lower cell surface ALK levels seen by flow
cytometry (FIG. 17E). No ADCC was detected when SKNAS cells (untreated or
antibody-treated) were used as targets (FIG. 18D, right panel),
consistent with their lack of ALK expression. Thus, targeting ALK with an
antagonistic antibody can effectively inhibit growth and induce
cytotoxicity of neuroblastoma cell lines harboring either wild-type or
mutated forms of activated ALK.
Crizotinib Treatment Induces Cell Surface Accumulation of ALK
[0173] Treatment with a combination of TKIs and therapeutic antibodies
that both target the same tumor antigen, such as EGFR (Regales et al.
(2009) J. Clin. Invest., 119:3000-10) or HER2 (Scaltriti et al. (2009)
Oncogene 28:803-14), has been shown to enhance the degree of tumor growth
inhibition and cytotoxicity that can be elicited by either agent alone.
One possible mechanism for this is increased cell surface accumulation of
the targeted RTK that results from RTK stabilization upon TKI binding
(Bougherara et al. (2009) Mol. Cancer Res., 7:1525-33; Tabone-Eglinger et
al. (2008) Clin. Cancer Res., 14:2285-94). Certain activating RTK
mutations, including several in c-Kit, may destabilize the RTK and cause
intracellular (likely endoplasmic reticulum) accumulation that can be
reversed by TKI treatment--leading to increased cell surface expression
(Bougherara et al. (2009) Mol. Cancer Res., 7:1525-33; Tabone-Eglinger et
al. (2008) Clin. Cancer Res., 14:2285-94). The relatively reduced
sensitivity of F1174L ALK expressing SY5Y cells to ALK antibody treatment
(FIG. 18B, 18D) prompted us to investigate a similar possibility for ALK.
[0174] To explore the effects of TKIs on surface ALK levels in
neuroblastoma cells, SY5Y cells were treated with a range of crizotinib
doses (or vehicle). After 72 hours, cells were harvested and analyzed for
cell surface ALK expression by flow cytometry. As shown in FIG. 19A,
treatment with 1000 nM crizotinib resulted in a substantial increase in
cell surface ALK levels for SY5Y cells, with a 51.4% increase in mean
fluorescence intensity for cells treated with 1000 nM crizotinib
(MFI=636) compared with vehicle treated SY5Y (MFI=420), or isotype
control-stained (MFI=90). The enhancement in cell surface ALK levels was
dose dependent (FIG. 19B), and increased with the time of crizotinib
exposure (FIG. 19C). Up-regulation of cell surface ALK levels in
crizotinib-treated cells was first evident at approximately 8 hours
post-treatment, and continued to increase over the 72 hour period tested.
The possibility that crizotinib binding might induce conformational
changes in ALK that could stabilize or expose the epitope to which the
staining antibody was binding--increasing antibody binding and thus the
fluorescence signal in flow cytometry--was also considered. To control
for this possibility, the experiment was repeated using a second anti-ALK
antibody (mAb46) known to bind to an epitope distant from that of mAb14
(Moog-Lutz et al. (2005) J. Biol. Chem., 280:26039-48).
Crizotinib-induced enhancement of cell surface ALK levels was also
observed in this experiment (FIG. 19D), indicating that crizotinib
promotes cell surface accumulation of its target RTK.
Crizotinib Sensitizes Cells to Growth Inhibition by ALK Antibody Treatment
[0175] To test the hypothesis that crizotinib-induced accumulation of cell
surface ALK sensitizes cells to ALK antibody treatment, the ability of
the antagonist ALK antibody to inhibit growth of SY5Y cells alone or in
combination with crizotinib was compared. As shown in FIG. 20A, treatment
with either crizotinib alone (at a sub-IC.sub.50 dose of 333 nM) or ALK
antibody alone (at 10 .mu.g/ml) led to measurable growth inhibition.
However, combined treatment with both TKI and ALK antibody had a
significantly larger inhibitory effect as compared to TKI alone
(p<0.0001) or antibody alone (p<0.001), leading to almost complete
growth inhibition of SY5Y cells in vitro. Increases in total ALK levels
were also seen by Western blotting (FIG. 20B) in cells treated with
crizotinib (alone or in combination with ALK antibody), consistent with
the flow cytometry results shown in FIG. 19. On the other hand, levels of
phosphorylated ALK were substantially diminished by treatment with
crizotinib, either alone or together with antibody (FIG. 20B), suggesting
that the TKI stabilizes ALK while simultaneously blocking its activation.
It also considered whether crizotinib-induced up-regulation of cell
surface ALK might promote ADCC-mediated effects of the ALK antibody. To
address this, the in vitro ADCC assays was repeated using lymphocytes as
effectors and SY5Y cells pre-incubated with crizotinib or vehicle as
targets. As shown in FIG. 20C, crizotinib pre-incubation significantly
increased ADCC at effector to target ratios of 50:1 (crizotinib-treated
mean=55.7.+-.9.3%; vehicle-treated mean=31.1.+-.14.7%; p=0.0331) and 25:1
(crizotinib-treated mean=33.7.+-.2.5%; vehicle-treated
mean=17.3%.+-.7.9%; p=0.0262), providing further evidence for the ability
of crizotinib to sensitize ALK-mutated neuroblastoma cells to ALK
antibody treatment.
ALK Antibody Improves Sensitivity to a Broad Range of Crizotinib Doses
[0176] Since the previous experiments were conducted at a fixed dose of
crizotinib, it was then explored whether ALK antibody treatment could
improve sensitivity of neuroblastoma cells to crizotinib treatment across
a range of doses. SY5Y cellswere treated with a 4-log range of crizotinib
doses in the presence or absence of ALK antibody. As shown in FIG. 21A,
the addition of ALK antibody significantly enhanced growth inhibition at
all crizotinib doses except for the highest dose of 10,000 nM, a
supra-lethal dose at which the majority of TKI effect is likely to be
off-target. Moreover, these data reveal that combining the ALK antibody
shifts the dose-response curve for crizotinib so that a low dose (10 nM)
of crizotinib in combination with anti-ALK induces more growth inhibition
(mean=33.7.+-.2.8%) than seen with 333 nM crizotinib alone (mean=25.7%,
SD=6.5%). As suggested by this finding, antibody treatment reduced the
IC.sub.50 for crizotinib treatment of SY5Y cells from 3018 nM (crizotinib
alone) to 1745 nM for dual therapy (FIG. 21B).
Dual ALK Targeting Enhances Programmed Cell Death
[0177] To determine the effect of crizotinib and ALK antibody treatment on
cell cycle progression, the impact of TKI and/or antibody exposure on
SY5Y cellular DNA content was analyzed by flow cytometry. As shown in
FIG. 22A, and quantified in FIG. 22B, treatment with antibody alone led
to a small, but significant, increase in the G0/G1 fraction
(antibody--treated mean=69.2.+-.0.5%; vehicle-treated mean=65.7.+-.0.3%)
and a small but significant decrease in the sub G0 fraction (antibody
treated mean=11.4.+-.0.3%; vehicle-treated mean=13.7.+-.0.2%), suggesting
that the main mechanism of antibody action may be G1 arrest. On the other
hand, dual antibody and TKI ALK targeting led to large and significant
increases in the sub GO fraction (mAb+crizotinib-treated
mean=38.0.+-.0.4%), suggesting induction of programmed cell death as the
dominant mechanism of dual ALK targeting. Treatment with crizotinib alone
also increased the sub GO fraction, but to a smaller extent than seen
with dual treatment, consistent with the findings above that anti-ALK
potentiates crizotinib effects.
[0178] While certain of the preferred embodiments of the present invention
have been described and specifically exemplified above, it is not
intended that the invention be limited to such embodiments. Various
modifications may be made thereto without departing from the scope and
spirit of the present invention, as set forth in the following claims.
Sequence CWU
1
6121RNAArtificial SequencesiRNA sense strand 1gggccuguau accggauaau u
21221RNAArtificial SequencesiRNA
sense strand 2gugccaugcu gccaguuaau u
21321RNAArtificial SequencesiRNA sense strand 3ccgcuuugcc
gauagaauau u
21421RNAArtificial SequencesiRNA sense strand 4ggagccaccu acguauuuau u
2151620PRTHomo sapiens 5Met
Gly Ala Ile Gly Leu Leu Trp Leu Leu Pro Leu Leu Leu Ser Thr1
5 10 15Ala Ala Val Gly Ser Gly Met Gly
Thr Gly Gln Arg Ala Gly Ser Pro 20 25
30Ala Ala Gly Pro Pro Leu Gln Pro Arg Glu Pro Leu Ser Tyr Ser
Arg 35 40 45Leu Gln Arg Lys Ser
Leu Ala Val Asp Phe Val Val Pro Ser Leu Phe 50 55
60Arg Val Tyr Ala Arg Asp Leu Leu Leu Pro Pro Ser Ser Ser
Glu Leu65 70 75 80Lys
Ala Gly Arg Pro Glu Ala Arg Gly Ser Leu Ala Leu Asp Cys Ala
85 90 95Pro Leu Leu Arg Leu Leu Gly
Pro Ala Pro Gly Val Ser Trp Thr Ala 100 105
110Gly Ser Pro Ala Pro Ala Glu Ala Arg Thr Leu Ser Arg Val
Leu Lys 115 120 125Gly Gly Ser Val
Arg Lys Leu Arg Arg Ala Lys Gln Leu Val Leu Glu 130
135 140Leu Gly Glu Glu Ala Ile Leu Glu Gly Cys Val Gly
Pro Pro Gly Glu145 150 155
160Ala Ala Val Gly Leu Leu Gln Phe Asn Leu Ser Glu Leu Phe Ser Trp
165 170 175Trp Ile Arg Gln Gly
Glu Gly Arg Leu Arg Ile Arg Leu Met Pro Glu 180
185 190Lys Lys Ala Ser Glu Val Gly Arg Glu Gly Arg Leu
Ser Ala Ala Ile 195 200 205Arg Ala
Ser Gln Pro Arg Leu Leu Phe Gln Ile Phe Gly Thr Gly His 210
215 220Ser Ser Leu Glu Ser Pro Thr Asn Met Pro Ser
Pro Ser Pro Asp Tyr225 230 235
240Phe Thr Trp Asn Leu Thr Trp Ile Met Lys Asp Ser Phe Pro Phe Leu
245 250 255Ser His Arg Ser
Arg Tyr Gly Leu Glu Cys Ser Phe Asp Phe Pro Cys 260
265 270Glu Leu Glu Tyr Ser Pro Pro Leu His Asp Leu
Arg Asn Gln Ser Trp 275 280 285Ser
Trp Arg Arg Ile Pro Ser Glu Glu Ala Ser Gln Met Asp Leu Leu 290
295 300Asp Gly Pro Gly Ala Glu Arg Ser Lys Glu
Met Pro Arg Gly Ser Phe305 310 315
320Leu Leu Leu Asn Thr Ser Ala Asp Ser Lys His Thr Ile Leu Ser
Pro 325 330 335Trp Met Arg
Ser Ser Ser Glu His Cys Thr Leu Ala Val Ser Val His 340
345 350Arg His Leu Gln Pro Ser Gly Arg Tyr Ile
Ala Gln Leu Leu Pro His 355 360
365Asn Glu Ala Ala Arg Glu Ile Leu Leu Met Pro Thr Pro Gly Lys His 370
375 380Gly Trp Thr Val Leu Gln Gly Arg
Ile Gly Arg Pro Asp Asn Pro Phe385 390
395 400Arg Val Ala Leu Glu Tyr Ile Ser Ser Gly Asn Arg
Ser Leu Ser Ala 405 410
415Val Asp Phe Phe Ala Leu Lys Asn Cys Ser Glu Gly Thr Ser Pro Gly
420 425 430Ser Lys Met Ala Leu Gln
Ser Ser Phe Thr Cys Trp Asn Gly Thr Val 435 440
445Leu Gln Leu Gly Gln Ala Cys Asp Phe His Gln Asp Cys Ala
Gln Gly 450 455 460Glu Asp Glu Ser Gln
Met Cys Arg Lys Leu Pro Val Gly Phe Tyr Cys465 470
475 480Asn Phe Glu Asp Gly Phe Cys Gly Trp Thr
Gln Gly Thr Leu Ser Pro 485 490
495His Thr Pro Gln Trp Gln Val Arg Thr Leu Lys Asp Ala Arg Phe Gln
500 505 510Asp His Gln Asp His
Ala Leu Leu Leu Ser Thr Thr Asp Val Pro Ala 515
520 525Ser Glu Ser Ala Thr Val Thr Ser Ala Thr Phe Pro
Ala Pro Ile Lys 530 535 540Ser Ser Pro
Cys Glu Leu Arg Met Ser Trp Leu Ile Arg Gly Val Leu545
550 555 560Arg Gly Asn Val Ser Leu Val
Leu Val Glu Asn Lys Thr Gly Lys Glu 565
570 575Gln Gly Arg Met Val Trp His Val Ala Ala Tyr Glu
Gly Leu Ser Leu 580 585 590Trp
Gln Trp Met Val Leu Pro Leu Leu Asp Val Ser Asp Arg Phe Trp 595
600 605Leu Gln Met Val Ala Trp Trp Gly Gln
Gly Ser Arg Ala Ile Val Ala 610 615
620Phe Asp Asn Ile Ser Ile Ser Leu Asp Cys Tyr Leu Thr Ile Ser Gly625
630 635 640Glu Asp Lys Ile
Leu Gln Asn Thr Ala Pro Lys Ser Arg Asn Leu Phe 645
650 655Glu Arg Asn Pro Asn Lys Glu Leu Lys Pro
Gly Glu Asn Ser Pro Arg 660 665
670Gln Thr Pro Ile Phe Asp Pro Thr Val His Trp Leu Phe Thr Thr Cys
675 680 685Gly Ala Ser Gly Pro His Gly
Pro Thr Gln Ala Gln Cys Asn Asn Ala 690 695
700Tyr Gln Asn Ser Asn Leu Ser Val Glu Val Gly Ser Glu Gly Pro
Leu705 710 715 720Lys Gly
Ile Gln Ile Trp Lys Val Pro Ala Thr Asp Thr Tyr Ser Ile
725 730 735Ser Gly Tyr Gly Ala Ala Gly
Gly Lys Gly Gly Lys Asn Thr Met Met 740 745
750Arg Ser His Gly Val Ser Val Leu Gly Ile Phe Asn Leu Glu
Lys Asp 755 760 765Asp Met Leu Tyr
Ile Leu Val Gly Gln Gln Gly Glu Asp Ala Cys Pro 770
775 780Ser Thr Asn Gln Leu Ile Gln Lys Val Cys Ile Gly
Glu Asn Asn Val785 790 795
800Ile Glu Glu Glu Ile Arg Val Asn Arg Ser Val His Glu Trp Ala Gly
805 810 815Gly Gly Gly Gly Gly
Gly Gly Ala Thr Tyr Val Phe Lys Met Lys Asp 820
825 830Gly Val Pro Val Pro Leu Ile Ile Ala Ala Gly Gly
Gly Gly Arg Ala 835 840 845Tyr Gly
Ala Lys Thr Asp Thr Phe His Pro Glu Arg Leu Glu Asn Asn 850
855 860Ser Ser Val Leu Gly Leu Asn Gly Asn Ser Gly
Ala Ala Gly Gly Gly865 870 875
880Gly Gly Trp Asn Asp Asn Thr Ser Leu Leu Trp Ala Gly Lys Ser Leu
885 890 895Gln Glu Gly Ala
Thr Gly Gly His Ser Cys Pro Gln Ala Met Lys Lys 900
905 910Trp Gly Trp Glu Thr Arg Gly Gly Phe Gly Gly
Gly Gly Gly Gly Cys 915 920 925Ser
Ser Gly Gly Gly Gly Gly Gly Tyr Ile Gly Gly Asn Ala Ala Ser 930
935 940Asn Asn Asp Pro Glu Met Asp Gly Glu Asp
Gly Val Ser Phe Ile Ser945 950 955
960Pro Leu Gly Ile Leu Tyr Thr Pro Ala Leu Lys Val Met Glu Gly
His 965 970 975Gly Glu Val
Asn Ile Lys His Tyr Leu Asn Cys Ser His Cys Glu Val 980
985 990Asp Glu Cys His Met Asp Pro Glu Ser His
Lys Val Ile Cys Phe Cys 995 1000
1005Asp His Gly Thr Val Leu Ala Glu Asp Gly Val Ser Cys Ile Val Ser
1010 1015 1020Pro Thr Pro Glu Pro His Leu
Pro Leu Ser Leu Ile Leu Ser Val Val1025 1030
1035 1040Thr Ser Ala Leu Val Ala Ala Leu Val Leu Ala Phe
Ser Gly Ile Met 1045 1050
1055Ile Val Tyr Arg Arg Lys His Gln Glu Leu Gln Ala Met Gln Met Glu
1060 1065 1070Leu Gln Ser Pro Glu Tyr
Lys Leu Ser Lys Leu Arg Thr Ser Thr Ile 1075 1080
1085Met Thr Asp Tyr Asn Pro Asn Tyr Cys Phe Ala Gly Lys Thr
Ser Ser 1090 1095 1100Ile Ser Asp Leu
Lys Glu Val Pro Arg Lys Asn Ile Thr Leu Ile Arg1105 1110
1115 1120Gly Leu Gly His Gly Ala Phe Gly Glu
Val Tyr Glu Gly Gln Val Ser 1125 1130
1135Gly Met Pro Asn Asp Pro Ser Pro Leu Gln Val Ala Val Lys Thr
Leu 1140 1145 1150Pro Glu Val
Cys Ser Glu Gln Asp Glu Leu Asp Phe Leu Met Glu Ala 1155
1160 1165Leu Ile Ile Ser Lys Phe Asn His Gln Asn Ile
Val Arg Cys Ile Gly 1170 1175 1180Val
Ser Leu Gln Ser Leu Pro Arg Phe Ile Leu Leu Glu Leu Met Ala1185
1190 1195 1200Gly Gly Asp Leu Lys Ser
Phe Leu Arg Glu Thr Arg Pro Arg Pro Ser 1205
1210 1215Gln Pro Ser Ser Leu Ala Met Leu Asp Leu Leu His
Val Ala Arg Asp 1220 1225
1230Ile Ala Cys Gly Cys Gln Tyr Leu Glu Glu Asn His Phe Ile His Arg
1235 1240 1245Asp Ile Ala Ala Arg Asn Cys
Leu Leu Thr Cys Pro Gly Pro Gly Arg 1250 1255
1260Val Ala Lys Ile Gly Asp Phe Gly Met Ala Arg Asp Ile Tyr Arg
Ala1265 1270 1275 1280Ser Tyr
Tyr Arg Lys Gly Gly Cys Ala Met Leu Pro Val Lys Trp Met
1285 1290 1295Pro Pro Glu Ala Phe Met Glu
Gly Ile Phe Thr Ser Lys Thr Asp Thr 1300 1305
1310Trp Ser Phe Gly Val Leu Leu Trp Glu Ile Phe Ser Leu Gly
Tyr Met 1315 1320 1325Pro Tyr Pro
Ser Lys Ser Asn Gln Glu Val Leu Glu Phe Val Thr Ser 1330
1335 1340Gly Gly Arg Met Asp Pro Pro Lys Asn Cys Pro Gly
Pro Val Tyr Arg1345 1350 1355
1360Ile Met Thr Gln Cys Trp Gln His Gln Pro Glu Asp Arg Pro Asn Phe
1365 1370 1375Ala Ile Ile Leu Glu
Arg Ile Glu Tyr Cys Thr Gln Asp Pro Asp Val 1380
1385 1390Ile Asn Thr Ala Leu Pro Ile Glu Tyr Gly Pro Leu
Val Glu Glu Glu 1395 1400 1405Glu
Lys Val Pro Val Arg Pro Lys Asp Pro Glu Gly Val Pro Pro Leu 1410
1415 1420Leu Val Ser Gln Gln Ala Lys Arg Glu Glu
Glu Arg Ser Pro Ala Ala1425 1430 1435
1440Pro Pro Pro Leu Pro Thr Thr Ser Ser Gly Lys Ala Ala Lys Lys
Pro 1445 1450 1455Thr Ala
Ala Glu Ile Ser Val Arg Val Pro Arg Gly Pro Ala Val Glu 1460
1465 1470Gly Gly His Val Asn Met Ala Phe Ser
Gln Ser Asn Pro Pro Ser Glu 1475 1480
1485Leu His Lys Val His Gly Ser Arg Asn Lys Pro Thr Ser Leu Trp Asn
1490 1495 1500Pro Thr Tyr Gly Ser Trp Phe
Thr Glu Lys Pro Thr Lys Lys Asn Asn1505 1510
1515 1520Pro Ile Ala Lys Lys Glu Pro His Asp Arg Gly Asn
Leu Gly Leu Glu 1525 1530
1535Gly Ser Cys Thr Val Pro Pro Asn Val Ala Thr Gly Arg Leu Pro Gly
1540 1545 1550Ala Ser Leu Leu Leu Glu
Pro Ser Ser Leu Thr Ala Asn Met Lys Glu 1555 1560
1565Val Pro Leu Phe Arg Leu Arg His Phe Pro Cys Gly Asn Val
Asn Tyr 1570 1575 1580Gly Tyr Gln Gln
Gln Gly Leu Pro Leu Glu Ala Ala Thr Ala Pro Gly1585 1590
1595 1600Ala Gly His Tyr Glu Asp Thr Ile Leu
Lys Ser Lys Asn Ser Met Asn 1605 1610
1615Gln Pro Gly Pro 162064863DNAHomo sapiens
6atgggagcca tcgggctcct gtggctcctg ccgctgctgc tttccacggc agctgtgggc
60tccgggatgg ggaccggcca gcgcgcgggc tccccagctg cggggccgcc gctgcagccc
120cgggagccac tcagctactc gcgcctgcag aggaagagtc tggcagttga cttcgtggtg
180ccctcgctct tccgtgtcta cgcccgggac ctactgctgc caccatcctc ctcggagctg
240aaggctggca ggcccgaggc ccgcggctcg ctagctctgg actgcgcccc gctgctcagg
300ttgctggggc cggcgccggg ggtctcctgg accgccggtt caccagcccc ggcagaggcc
360cggacgctgt ccagggtgct gaagggcggc tccgtgcgca agctccggcg tgccaagcag
420ttggtgctgg agctgggcga ggaggcgatc ttggagggtt gcgtcgggcc ccccggggag
480gcggctgtgg ggctgctcca gttcaatctc agcgagctgt tcagttggtg gattcgccaa
540ggcgaagggc gactgaggat ccgcctgatg cccgagaaga aggcgtcgga agtgggcaga
600gagggaaggc tgtccgcggc aattcgcgcc tcccagcccc gccttctctt ccagatcttc
660gggactggtc atagctcctt ggaatcacca acaaacatgc cttctccttc tcctgattat
720tttacatgga atctcacctg gataatgaaa gactccttcc ctttcctgtc tcatcgcagc
780cgatatggtc tggagtgcag ctttgacttc ccctgtgagc tggagtattc ccctccactg
840catgacctca ggaaccagag ctggtcctgg cgccgcatcc cctccgagga ggcctcccag
900atggacttgc tggatgggcc tggggcagag cgttctaagg agatgcccag aggctccttt
960ctccttctca acacctcagc tgactccaag cacaccatcc tgagtccgtg gatgaggagc
1020agcagtgagc actgcacact ggccgtctcg gtgcacaggc acctgcagcc ctctggaagg
1080tacattgccc agctgctgcc ccacaacgag gctgcaagag agatcctcct gatgcccact
1140ccagggaagc atggttggac agtgctccag ggaagaatcg ggcgtccaga caacccattt
1200cgagtggccc tggaatacat ctccagtgga aaccgcagct tgtctgcagt ggacttcttt
1260gccctgaaga actgcagtga aggaacatcc ccaggctcca agatggccct gcagagctcc
1320ttcacttgtt ggaatgggac agtcctccag cttgggcagg cctgtgactt ccaccaggac
1380tgtgcccagg gagaagatga gagccagatg tgccggaaac tgcctgtggg tttttactgc
1440aactttgaag atggcttctg tggctggacc caaggcacac tgtcacccca cactcctcaa
1500tggcaggtca ggaccctaaa ggatgcccgg ttccaggacc accaagacca tgctctattg
1560ctcagtacca ctgatgtccc cgcttctgaa agtgctacag tgaccagtgc tacgtttcct
1620gcaccgatca agagctctcc atgtgagctc cgaatgtcct ggctcattcg tggagtcttg
1680aggggaaacg tgtccttggt gctagtggag aacaaaaccg ggaaggagca aggcaggatg
1740gtctggcatg tcgccgccta tgaaggcttg agcctgtggc agtggatggt gttgcctctc
1800ctcgatgtgt ctgacaggtt ctggctgcag atggtcgcat ggtggggaca aggatccaga
1860gccatcgtgg cttttgacaa tatctccatc agcctggact gctacctcac cattagcgga
1920gaggacaaga tcctgcagaa tacagcaccc aaatcaagaa acctgtttga gagaaaccca
1980aacaaggagc tgaaacccgg ggaaaattca ccaagacaga cccccatctt tgaccctaca
2040gttcattggc tgttcaccac atgtggggcc agcgggcccc atggccccac ccaggcacag
2100tgcaacaacg cctaccagaa ctccaacctg agcgtggagg tggggagcga gggccccctg
2160aaaggcatcc agatctggaa ggtgccagcc accgacacct acagcatctc gggctacgga
2220gctgctggcg ggaaaggcgg gaagaacacc atgatgcggt cccacggcgt gtctgtgctg
2280ggcatcttca acctggagaa ggatgacatg ctgtacatcc tggttgggca gcagggagag
2340gacgcctgcc ccagtacaaa ccagttaatc cagaaagtct gcattggaga gaacaatgtg
2400atagaagaag aaatccgtgt gaacagaagc gtgcatgagt gggcaggagg cggaggagga
2460gggggtggag ccacctacgt atttaagatg aaggatggag tgccggtgcc cctgatcatt
2520gcagccggag gtggtggcag ggcctacggg gccaagacag acacgttcca cccagagaga
2580ctggagaata actcctcggt tctagggcta aacggcaatt ccggagccgc aggtggtgga
2640ggtggctgga atgataacac ttccttgctc tgggccggaa aatctttgca ggagggtgcc
2700accggaggac attcctgccc ccaggccatg aagaagtggg ggtgggagac aagagggggt
2760ttcggagggg gtggaggggg gtgctcctca ggtggaggag gcggaggata tataggcggc
2820aatgcagcct caaacaatga ccccgaaatg gatggggaag atggggtttc cttcatcagt
2880ccactgggca tcctgtacac cccagcttta aaagtgatgg aaggccacgg ggaagtgaat
2940attaagcatt atctaaactg cagtcactgt gaggtagacg aatgtcacat ggaccctgaa
3000agccacaagg tcatctgctt ctgtgaccac gggacggtgc tggctgagga tggcgtctcc
3060tgcattgtgt cacccacccc ggagccacac ctgccactct cgctgatcct ctctgtggtg
3120acctctgccc tcgtggccgc cctggtcctg gctttctccg gcatcatgat tgtgtaccgc
3180cggaagcacc aggagctgca agccatgcag atggagctgc agagccctga gtacaagctg
3240agcaagctcc gcacctcgac catcatgacc gactacaacc ccaactactg ctttgctggc
3300aagacctcct ccatcagtga cctgaaggag gtgccgcgga aaaacatcac cctcattcgg
3360ggtctgggcc atggcgcctt tggggaggtg tatgaaggcc aggtgtccgg aatgcccaac
3420gacccaagcc ccctgcaagt ggctgtgaag acgctgcctg aagtgtgctc tgaacaggac
3480gaactggatt tcctcatgga agccctgatc atcagcaaat tcaaccacca gaacattgtt
3540cgctgcattg gggtgagcct gcaatccctg ccccggttca tcctgctgga gctcatggcg
3600gggggagacc tcaagtcctt cctccgagag acccgccctc gcccgagcca gccctcctcc
3660ctggccatgc tggaccttct gcacgtggct cgggacattg cctgtggctg tcagtatttg
3720gaggaaaacc acttcatcca ccgagacatt gctgccagaa actgcctctt gacctgtcca
3780ggccctggaa gagtggccaa gattggagac ttcgggatgg cccgagacat ctacagggcg
3840agctactata gaaagggagg ctgtgccatg ctgccagtta agtggatgcc cccagaggcc
3900ttcatggaag gaatattcac ttctaaaaca gacacatggt cctttggagt gctgctatgg
3960gaaatctttt ctcttggata tatgccatac cccagcaaaa gcaaccagga agttctggag
4020tttgtcacca gtggaggccg gatggaccca cccaagaact gccctgggcc tgtataccgg
4080ataatgactc agtgctggca acatcagcct gaagacaggc ccaactttgc catcattttg
4140gagaggattg aatactgcac ccaggacccg gatgtaatca acaccgcttt gccgatagaa
4200tatggtccac ttgtggaaga ggaagagaaa gtgcctgtga ggcccaagga ccctgagggg
4260gttcctcctc tcctggtctc tcaacaggca aaacgggagg aggagcgcag cccagctgcc
4320ccaccacctc tgcctaccac ctcctctggc aaggctgcaa agaaacccac agctgcagag
4380atctctgttc gagtccctag agggccggcc gtggaagggg gacacgtgaa tatggcattc
4440tctcagtcca accctccttc ggagttgcac aaggtccacg gatccagaaa caagcccacc
4500agcttgtgga acccaacgta cggctcctgg tttacagaga aacccaccaa aaagaataat
4560cctatagcaa agaaggagcc acacgacagg ggtaacctgg ggctggaggg aagctgtact
4620gtcccaccta acgttgcaac tgggagactt ccgggggcct cactgctcct agagccctct
4680tcgctgactg ccaatatgaa ggaggtacct ctgttcaggc tacgtcactt cccttgtggg
4740aatgtcaatt acggctacca gcaacagggc ttgcccttag aagccgctac tgcccctgga
4800gctggtcatt acgaggatac cattctgaaa agcaagaata gcatgaacca gcctgggccc
4860tga
4863
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