Abstract 336: Genomic annotation of non-small cell lung cancer patient-derived xenograft models for personalized cancer therapy.
Authors: Desai Sonal J. , Goodwin Neal , Gandour-Edwards Regina , Calhoun Royce F. , Cooke David T. , Beckett Laurel A. , Maus Martin K.H. , Astrow Stephanie H. , Mack Philip C. , de Vere White Ralph , Gandara David R. , Li Tianhong 
Published: August 2014

Background: Recent studies have characterized non-small cell lung cancer (NSCLC) as one of the most genomically deranged of all cancers, necessitating that both new drug development and patient therapy account for intra- and inter-patient tumor heterogeneity. Clinically annotated NSCLC patient-derived xenograft (PDX) models represent a novel approach to integrate this genomic complexity into a clinically relevant pre-clinical platform. We here describe molecular characterization to profile all currently “druggable” oncogenes for NSCLC in paired PDXs and original patient NSCLC tumor (PT).

Method: Genomic DNA from archival formalin-fixed, paraffin-embedded (FFPE) PT and fresh first human-to-mouse (P0) NSCLC PDX tumors were isolated and subjected to oncogene mutational profiling using Sequenom's OncoCarta Panel v1. This panel detects 238 mutations in 19 genes commonly altered in cancer. RT-PCR-based molecular analyses of EGFR and KRAS mutations, EML4-ALK fusion transcripts, and RNA expression levels of ERCC1, RRM1 and TS genes were performed by Response Genetics, Inc. Genomic DNA from 3 serially passaged NSCLC PDX tumors (2 KRAS and 1 EGFR mutation models) up to 5 passages were also analyzed.

Results: In the first 7 of 9 patient-PDX NSCLC models tested, oncogene mutational fidelity was preserved between PDX and PT with a good correlation of molecular biomarker expression (p&lt;0.01). Two paired models had discrepancies in genotyping: from harboring 2 or 3 oncomutations at a frequency of 5-17% in PT to no mutation detected in P0 tumors), likely due to intra-patient tumor heterogeneity from clonal evolution. Of 3 models that have serial passaged tumors, the frequencies of oncomutation in each model were similar among the same passage (P0) or serial passage (P0 to P5) tumors. In several models tested for in vivo drug efficacy based on the molecular biomarker expression, results matched treatment outcome of the original patients.,

Conclusion: Our results validate the overall genomic fidelity of PDX tumors compared to original PT. Molecular characterization of individual tumor results in a clinically and genomically annotated PDX model with potential utility for selecting and validating clinically relevant drug target(s) for personalized cancer therapy.

Acknowledgement: Supported by UC Davis Comprehensive Cancer Center Developmental Award (NIH/NCI P30CA093373), UL1 RR024146 from the National Center for Research Resources, the Jackson Laboratory, Response Genetics Inc., and the Addario Foundation.

Citation Format: Sonal J. Desai, Neal Goodwin, Regina Gandour-Edwards, Royce F. Calhoun, David T. Cooke, Laurel A. Beckett, Martin K.H. Maus, Stephanie H. Astrow, Philip C. Mack, Ralph deVere White, David R. Gandara, Tianhong Li. Genomic annotation of non-small cell lung cancer patient-derived xenograft models for personalized cancer therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 336. doi:10.1158/1538-7445.AM2013-336