Abstract 936: Single cell analysis reveals cancer stem cell heterogeneities in hepatocellular carcinoma

Abstract

Abstract Tumor heterogeneity represents a major obstacle to effective cancer treatment and personalized medicine. Hepatocellular carcinoma (HCC) is clinically and biologically heterogeneous, which is partly attributed to the presence of hepatic cancer stem cells (CSCs). CSC surface makers can have overlapping expression or exclusive expression of different subpopulations of hepatic CSCs, and these cells may contain different oncogenic changes. The existence of various CSC surface-marked subpopulations might pose a problem for CSC targeted therapeutics. Little is known about whether there are shared or distinct pathways in different subpopulations. Moreover, it remains unknown whether heterogeneity exists within certain subpopulations. Thus, we propose to profile the global transcriptome of surface-marked CSCs (EpCAM+, CD133+ and CD24+) at the single-cell level using index flow cytometric sorting and single-cell RNA sequencing technology. We statistically compared mRNA transcriptomes of individual single cells of triple positive (EpCAM+/ CD133+ /CD24+) CSCs and triple negative (EpCAM-/ CD133- /CD24-) cells. Further, we compared the triple positive and the triple negative cells at the single cell level in terms of their self-renew capability in both normoxic and hypoxic conditions. Our results show that at the single cell level, the transcriptomic profiles show a high-degree of heterogeneity in HCC cell lines, meanwhile, there is a dramatic difference between triple positive and triple negative cells in their transcriptomic profiles. There is a high-degree of intra-tumor and inter-tumor heterogeneity observed in single cell transcriptomes of HCC patients’ samples. Triple positive CSC single cells show continuous rather than discrete stemness-related gene expression patterns. In parallel, the self-renewal capability of triple positive cells also exhibits heterogeneity, while triple negative cells show little self-renewal capability. Thus, our single cell analysis study reveals molecular and biological heterogeneity of cancer stem cells in HCC, which may provide insight into the underlying mechanisms of how CSCs contribute to tumor heterogeneity and underscore key pathways and novel targets for hepatic CSC therapy. Citation Format: Hongping Zheng, Yotsawat Pomyen, Maria Hernandez, Caiyi Li, Ferenc Livak, Tim Greten, Anuradha Budhu, Xin Wang. Single cell analysis reveals cancer stem cell heterogeneities in hepatocellular carcinoma [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 936. doi:10.1158/1538-7445.AM2017-936