studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 1165A
1965
Somatic Mutational Analysis by Next Generation RNA
Sequencing Reveals Frequent Mutation of Chromatin
and Chromosome Remodeling Genes in Gallbladder
Cancer
Loretta K. Allotey 1 , Roongruedee Chaiteerakij 1,2 , Gavin R. Oliver
3 , Vivekananda Sarangi 3 , Renumathy Dhanasekaran 1 , Catherine
D. Moser 1 , Nasra H. Giama 1 , Daniel R. O’Brien 3 , Raymond
M. Moore 3 , Mia D. Champion 4 , Eric W. Klee 3 , Mitesh J. Borad 5 ,
Lewis R. Roberts 1 ; 1 Division of Gastroenterology and Hepatology,
Mayo Clinic College of Medicine, and Mayo Clinic Cancer Center,
Rochester, MN; 2 Department of Medicine, Faculty of Medicine,
Chulalongkorn University and King Chulalongkorn Memorial Hospital,
Thai Red Cross Society, Bangkok, Thailand; 3 Department of
Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN;
4 Department of Biomedical Statistics and Informatics, Mayo Clinic,
Scottsdale, AZ; 5 Division of Hematology and Medical Oncology,
Mayo Clinic, Scottsdale, AZ
Background/Aim: Gallbladder cancer (GBC) is uncommon,
with an incidence of 2 per 100,000/year in the US. Due
to its asymptomatic nature, most patients present at a late
stage. Current standard chemotherapy and radiation therapy
only achieve a 5-year survival rate of 10% in patients with
advanced cancer. Thus improved understanding of the molecular
pathogenesis of GBC is urgently needed for rational design
of effective therapies. We therefore aimed to investigate the
mutational landscape of human gallbladder cancer. Methods:
12 GBCs were RNA sequenced on the Illumina Hi-Seq 2000
platform. Single Nucleotide Variants (SNVs) were called from
the genome-aligned reads using Unified Genotyper. Stringent
filtering criteria were used to identify variants of high
confidence (Inclusion criteria: Depth of Coverage>10, Quality
Score>0.05, Minor Allele Frequency1
patient). To identify variants in clinically relevant genes, variants
meeting the above criteria were selected and compared to
a generated list of 1,434 genes reported in COSMIC, Cancer
Panels, or in the literature to have relevance to cancer and epigenetics
processes. Survival in months was determined for each
patient and select genes were investigated for their association
with survival by Kaplan Meier analysis. The significance of the
differences in survival between groups was analyzed using the
Log-Rank test. Results: 69 SNVs were identified in 28 clinically
relevant genes. Fifteen of the 28 genes (53%) have known
effects on epigenetic processes, including TP53 (mutated in
50% of tumors), SETD1A (33%), MLL2 (33%), SRCAP (25%),
MSH6 (16%), MSL1 (16%), ATXN7 (16%), SUV420H1 (16%),
LSG1 (16%), RSF1 (16%), MCM7 (16%), DNAJC2 (16%),
AHCTF1 (16%), BRD4 (16%), and NUP214 (16%). DAVID
Functional annotation and WebGestalt Gene Ontology Analysis
of the 28 genes revealed that 11 genes (ATXN7, SRCAP,
DNAJC2, MSL1, SUV420H1, BRD4, MLL2, SETD1A, TP53,
and RSF1) are involved in chromatin and chromosome remodeling.
Of the 11 genes, mutations in the SRCAP gene were
found to have a marginally significant effect on survival. The
three patients with mutation in the SRCAP gene had a survival
of 4 months while patients without mutations in SRCAP had
a survival of 9 months (P = 0.06). Conclusions: Chromatin
and chromosome remodeling genes are frequently mutated in
GBC and provide a starting point for further functional studies.
Patients with SRCAP mutations show a trend towards poorer
survival than patients with wild-type SRCAP. Validation of these
findings in a larger cohort is underway.
Disclosures:
Lewis R. Roberts - Grant/Research Support: Bristol Myers Squibb, ARIAD Pharmaceuticals,
BTG, Wako Diagnostics, Inova Diagnostics, Gilead Sciences, Five
Prime Therapeutics
The following authors have nothing to disclose: Loretta K. Allotey, Roongruedee
Chaiteerakij, Gavin R. Oliver, Vivekananda Sarangi, Renumathy Dhanasekaran,
Catherine D. Moser, Nasra H. Giama, Daniel R. O’Brien, Raymond M. Moore,
Mia D. Champion, Eric W. Klee, Mitesh J. Borad
1966
Differential Antitumor Effects of FGFR Inhibitors on a
Novel Cholangiocarcinoma Patient-Derived Xenograft
Mouse Model Expressing an FGFR2-CCDC6 Fusion Protein
Yu Wang 1,2 , Hassan M. Shaleh 2 , Xiwei Ding 2,3 , Shaoqing
Wang 2,4 , Roongruedee Chaiteerakij 2,5 , Kais Zakharia 2 , Loretta
K. Allotey 2 , Essa A. Mohamed 2 , Catherine D. Moser 2 , Steven
Alberts 6 , Joseph M. Gozgit 7 , Mitesh J. Borad 8 , Lewis R. Roberts 2 ;
1 Department of Hepatobiliary Surgery, Nanfang Hospital, Southern
Medical University, Guangzhou, China; 2 Division of Gastroenterology
and Hepatology, Mayo Clinic College of Medicine, and
Mayo Clinic Cancer Center, Rochester, MN; 3 Department of Gastroenterology,
Drum Tower Hospital, Affiliated to Medical School
of Nanjing University, Nanjing, China; 4 Department of Pathology,
Qiqihar Medical University, Qiqihar, China; 5 Department of Medicine,
Faculty of Medicine, Chulalongkorn University and King
Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok,
Thailand; 6 Department of Oncology, Mayo Clinic, Rochester,
MN; 7 ARIAD Pharmaceuticals, Inc., Cambridge, MA; 8 Division of
Hematology and Medical Oncology, Mayo Clinic, Scottsdale, AZ
Introduction: Cholangiocarcinoma (CCA) is a highly lethal
cancer with limited therapeutic options and a poor prognosis.
Recent genomic analysis has revealed the presence of
FGFR2 fusion proteins in up to 13% of intrahepatic CCAs.
The FGFR fusion proteins appear to play a key role in cancer
progression. Tumors harboring FGFR fusions have demonstrated
enhanced sensitivity to FGFR inhibitors, suggesting that
CCA patients with FGFR2 fusions may benefit from targeted
FGFR2 kinase inhibition. The effects of FGFR kinase inhibitors
ponatinib, dovitinib and BGJ398 have not been evaluated in
CCA bearing FGFR fusions. We aimed to assess the relative
sensitivity of a novel in vivo CCA PDX mouse model bearing
an FGFR2-CCDC6 fusion protein to different FGFR inhibitors.
Methods: LIV31 is a PDX model derived in NSG SCID mice
from a metastatic lung nodule resected from a patient with
stage IV intrahepatic CCA. Subsequent passage of the PDX
tumor into nude mice was successful. Detailed assay confirmed
that LIV31 harbors a transcript encoding an FGFR2-CCDC6
fusion protein. LIV31 cells were implanted subcutaneously into
the flanks of nude mice. When tumor volumes reached 150-
250 mm3 the mice were randomized into four groups: vehicle,
ponatinib 25 mg/kg, dovitinib 30 mg/kg, or BGJ398 15
mg/kg. The drugs were administered daily by oral gavage at
doses previously shown to be tolerated by mice. Tumor volumes
and mouse weights were measured once a week. Tumor
growth curves were compared. After 63 days treatment, the
animals were euthanized and xenografts were examined by
histology, Ki-67 IHC, Tunel staining and Western blotting for
pFGFR2 and the FGFR pathway downstream mediators pFRS2,
pAKT, and pERK. Results: All three FGFR inhibitors significantly
inhibited the growth of the FGFR2-CCDC6 fusion mouse PDX
tumors when compared with vehicle (P