Abstract 2433: SERPINA12 promotes the tumorigenic capacity of hepatocellular carcinoma stem cells through hyperactivation of AKT/β-catenin signaling

Abstract Hepatocellular carcinoma (HCC) is an aggressive disease with a poor clinical outcome. Understanding the mechanisms that drive cancer stemness, which we now know is the root cause of therapy failure and tumor recurrence, is fundamental for designing improved therapeutic strategies. The aim of this study is to identify molecular players specific to CD133+ HCC to better design drugs that can precisely interfere with cancer stem cells (CSCs) but not normal stem cell function. Transcriptome profiling of epithelial-specific ‘normal’ CD133+ cells isolated from fetal and regenerating liver against ‘HCC’ CD133+ cells isolated from proto-oncogene driven and inflammation-associated HCC revealed preferential overexpression of SERPINA12 in HCC but not fetal and regenerating liver cells. SERPINA12 upregulation in HCC is tightly associated with aggressive clinical and stemness features, including survival, tumor stage, cirrhosis, and stemness signatures related to embryonic stem cells, oncogenic dedifferentiation and undifferentiated HCC status. Enrichment of SERPINA12 in HCC is mediated by promoter binding of the well-recognized β-catenin effector TCF7L2 to drive SERPINA12 transcriptional activity. Functional characterization identified a unique and novel role of endogenous SERPINA12 in promoting self-renewal, therapy resistance and metastatic abilities. Mechanistically, SERPINA12 functioned through binding to GRP78, resulting in a hyperactivated AKT/GSK3β/β-catenin signaling cascade, forming a positive feed-forward loop. Intravenous administration of rAVV8-shSERPINA12 sensitized HCC cells to sorafenib and impeded the CSC subset in an immunocompetent HCC mouse model. Collectively, our findings revealed that SERPINA12 is preferentially overexpressed in epithelial HCC CD133+ cells and is a key contributor to HCC initiation and progression by driving an AKT/β-catenin feed-forward loop. Citation Format: Huajian Yu, Lei Zhou, Jane Ho-Chun Loong, Ka-Hei Lam, Tin-Lok Wong, Kai-Yu Ng, Man Tong, Victor WS Ma, Yanyan Wang, Xiang Zhang, Terence K Lee, Jing-Ping Yun, Jun Yu, Stephanie Ma. SERPINA12 promotes the tumorigenic capacity of hepatocellular carcinoma stem cells through hyperactivation of AKT/β-catenin signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2433.