Abstract 5169: Validation of genetically defined Oncopig hepatocellular carcinoma cell lines for <i>in vitro</i> evaluation of targeted therapeutic efficacy

Abstract Hepatocellular carcinoma (HCC) is the second leading cause of cancer related death worldwide with a 5-year survival rate of 18%. Development of novel targeted therapeutics to advance HCC precision medicine approaches is challenging due to a lack of malleable large animal HCC models that replicate human genetics, anatomy, metabolism, and physiology. We previously demonstrated our ability to develop HCC cell lines and tumors that recapitulate clinically relevant characteristics of human HCC utilizing the Oncopig cancer model (capable of forming tumors through induced KRASG12D and TP53R167H expression). Here, we demonstrate our ability to develop Oncopig HCC cell lines with differential therapeutic susceptibilities through introduction of clinically relevant HCC driver mutations (PTENKO, AXIN1KO, or ARID1KO) via CRISPR-Cas9 gene editing. Specifically, we demonstrate that PTENKO increases susceptibility to PI3K inhibitors currently in clinical trials for treatment of PTEN null HCC and other cancer types. Therapeutic susceptibility of the established Oncopig WT, PTENKO, AXIN1KO, and ARID1KO HCC cell lines was assessed for PI3K inhibitors (GSK2636771, BAY 80-6946, and BKM120). Consistent with human studies, Oncopig PTENKO HCC cell lines displayed significantly increased sensitivity to GSK2636771 and BAY 80-6946, but not BKM120, compared to WT and PI3K inhibitor non-responsive AXIN1KO and ARID1AKO cells (see Table). In addition, Oncopig PTENKO HCC cells possessed significantly increased proliferation and migration rates compared to WT Oncopig HCC cells (1.6 and 2.8 fold, respectively; p &amp;lt; 0.01). These results validate the utility of the Oncopig HCC model for preclinical evaluation of novel targeted therapeutics in vitro. Future work demonstrating consistent results in vivo will enable the genetically defined Oncopig HCC model to be an ideal animal system to test precision medicine therapeutics prior to entry into the clinic. Citation Format: Mahmoud Khalafalla, Navin Viswakarma, Lobna Elkhadragy, Theresa K. Kelly, Mark Eccleston, Lawrence B. Schook, Ron C. Gaba, Kyle M. Schachtschneider. Validation of genetically defined Oncopig hepatocellular carcinoma cell lines for in vitro evaluation of targeted therapeutic efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5169.