Abstract 1988: The pivotal roles of adipocytes on regulation of cancer stemness and drug resistance in hepatocellular carcinoma

Abstract

Abstract Hepatocellular carcinoma (HCC) is one of the deadliest cancers in the world with less than 10% 5-year survival rate. Liver cancer stem cells (CSCs) are sub-populations of the cancer cells that have been found to play a crucial role in tumor relapse and therapeutic resistance. Increasing reports showed the significant correlation between non-alcoholic fatty liver disease (NAFLD) and HCC development. Based on this evidence, we hypothesize adipocytes, one of the key cellular factors within the tumor microenvironment, play a crucial role in HCC development and progression via regulation of liver CSCs. To verify this, we have employed a co-culture system to dissect the potential cross-talk between fully differentiated adipocytes and HCC cells. Our pilot data showed that adipocytes enhanced the self-renewal ability of HCC cells through indirect paracrine secretion. Based on this finding, we examined the effect of the conditioned medium of adipocytes on regulation of liver CSC. Consistently, we found that HCC cells pre-incubated with conditioned medium of adipocytes showed enhanced in vivo tumorigenicity and chemo-resistance to doxorubicin and sorafenib. Furthermore, conditioned medium of adipocytes promoted the migration and invasion abilities of HCC cells. To delineate the molecular mechanism of how adipocytes, exert its CSC enhancing effect on HCC cells, we have collected the conditioned medium derived from adipocytes and analyzed their secretome profiles using Orbitrap Liquid Chromatography-Mass spectrometry. Upon analysis, we identified 209 proteins, among which we have focused on two proteins (CSF1 and FABP4) for further analysis as these are preferentially secreted from adipocytes. Respective inhibitors of the proteins are used to study the specificity of the protein in the medium and the downstream studied with the help of RNA sequencing which has been performed on conditioned medium treated HCC cells. Collectively, we demonstrated the pivotal role of adipocytes on regulation of liver CSCs through paracrine secretion. Thus, targeting adipocytes-derived signaling cascade may be a novel therapeutic strategy for treatment of fatty liver induced HCC. Citation Format: Shilpa Gurung, Terence Kin-Wah Lee. The pivotal roles of adipocytes on regulation of cancer stemness and drug resistance in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1988.