Abstract 4373: Lack of FGF21 promotes NASH-HCC transition via exosome-mediated carcinogenetic signaling

Abstract

Abstract Background: Nonalcoholic steatohepatitis (NASH) is the most severe form of non-alcoholic fatty liver disease (NAFLD) and a potential precursor of hepatocellular carcinoma (HCC). FGF21, with its metabolic benefits, was reported as the liver safeguard to protect from obesity, diabetes, and NAFLD. Recent study showed an exosome based FGF21 inhibition via organs communication to regulate hepatic metabolism. However, the role of the exosome-FGF21 axis in NASH-HCC has never been studied. Aim: To study the exosome based FGF21 metabolic regulation during NASH-HCC carcinogenetic transformation. Methods: NASH-HCC model was induced in FGF21 knockout (KO) mice and wild type (WT) control using methionine-choline-deficient diets (MCD) and diethylnitrosamine (DEN). The exosomes releasing, miRNA and protein contents were analyzed in the primary cultured hepatocytes from the liver tissues of NASH-HCC mice (KO and WT) as well as benign controls. FGF21 was knockdown (KD) by shRNA in a mouse hepatoma cell line (Hepa1-6) and a benign mouse hepatocyte cell line (FL83B) to investigate the potential carcinogenetic signaling related to exosome-FGF21 axis. Result: NASH-HCC model was successfully established with confirmation of the metabolic disorders and liver cancer development. Early HCC detection and increased HCC incidence were found in the KO-MCD mice (P<0.05 versus KO-CD and WT controls). The collected exosomes from primary cultured hepatocytes and cell lines were identified using the antibodies of Tsg101, CD63 and cytochrome C by western blotting and immunofluorescent staining. In the KO-MCD mice, exosomes retained in the cytosol of benign hepatocyte but released increasingly from cancer cell. Similar results were showed in the Hepa1-6KD cells and the FL83BKD cells. Aberrant EMT, and p53 and Wnt signaling was found in the KO-MCD mice as well as Hepa1-6KD cells challenged with free fatty acid. Conclusion: lack of FGF21 plays critical role for the exosome retention in hepatocytes of NASH mice but not in HCC mice. Abnormal traffic of exosomes contribute to the carcinogenetic signaling. This work was supported by an Institutional Development Award (IDeA) from the NIGMS of the National Institutes of Health under grant number P20GM113226. Citation Format: Youxi Yu, Robert C. Martin, Qianqian Zheng, Xiaoju Shi, Xingkai Liu, Wei Guo, Suping Li, Ping Zhang, Yan Li. Lack of FGF21 promotes NASH-HCC transition via exosome-mediated carcinogenetic signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4373.