Abstract 544: Hypoxia response signaling is linked to TACE resistance in hepatocellular carcinoma (HCC) patients

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and outcome is dismal, due to tumor heterogeneity and lack of effective treatment options for patients with later stage disease. Transcatheter arterial chemoembolization (TACE) is the gold standard of therapy for patients with intermediate to locally advanced tumors. TACE delivers a high dose of chemotherapy directly to the tumor via the hepatic artery, followed by an embolizing agent to restrict tumor blood supply. However, tumor hypoxia is linked to alterations in metabolism, such as increased glycolysis (the Warburg effect), and can lead to enhanced cell survival. Several randomized control trials (RCTs) showed a survival benefit with TACE, but only with strict patient selection criteria. In Asia, TACE is also commonly used as adjuvant therapy after surgical resection, yet RCTs evaluating adjuvant TACE have shown conflicting results, likely due to patient selection and stratification. We hypothesize that tumor gene expression is predictive of response following TACE, and that differential cellular metabolism resembling a hypoxic phenotype prior to treatment is responsible for TACE resistance. We retrospectively analyzed gene expression data in treatment-naive tumor tissue from a cohort of Chinese patients who received TACE. Using hierarchical clustering, followed by class comparison and survival risk prediction, we identified a 14-gene signature that is predictive of response vs. non-response to TACE, as measured by overall survival, independent of other clinical variables. We found that hypoxia- and glycolysis-related genes are enriched among differentially expressed genes in TACE Responders vs. Non-Responders, and that hypoxia master regulator HIF-1α and hypoxia target gene VEGF are significantly up-regulated in Non-Responders. We determined that a key glycolysis gene is up-regulated in Non-Responders, and conversely, two rate-limiting genes involved in gluconeogenesis, the pathway opposing glycolysis, are up-regulated in Responders. We also examined metabolomic data from the TACE cohort, and found an enrichment of glycolysis-related metabolites in Non-Responders, and gluconeogenesis-related metabolites in Responders. Further investigation will be required to connect altered glucose metabolism to TACE resistance and to determine driver genes linking hypoxia and metabolism, which, together with our 14-gene signature, may serve as a stratification tool to guide personalized treatment modalities for HCC patients. Citation Format: Valerie Fako, Joyce Lee, Tan-To Cheung, Irene O. Ng, Xin W. Wang. Hypoxia response signaling is linked to TACE resistance in hepatocellular carcinoma (HCC) patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 544. doi:10.1158/1538-7445.AM2017-544