Background & aims: Hepatocellular carcinoma (HCC) can be derived from cancer stem cells (CSCs), which contribute to tumor initiation, metastasis, chemoresistance, and post-treatment recurrence. A great variety of HCC CSCs resulting in diverse clinical manifestations have been reported. We aimed to elucidate how CSC diversity is regulated.

Methods: MicroRNAs deregulated in HCC were identified by using array-based microRNA profiling. Diversity of HCC CSCs was assayed by flow-cytometry, in vitro and in vivo assays for tumorigenicity.

Results: MiR-200b downregulation occurred in early HCC and associated with shorter disease-free and overall survival. Ectopic expression of miR-200b or silencing of ZEB1 led to a decrease in CD13+ and CD24+ HCC CSCs and an increase in EpCAM+ HCC CSCs. MiR-200b directly suppressed BMI1 and ZEB1 expressions. ZEB1 transcriptionally upregulated CD13 and CD24 expression and downregulated EpCAM expression via directly targeting their promoters. Neither miR-200b nor ZEB1 had obvious effects on CD133 or CD90 expression. Silencing CD13 or CD24 expression suppressed tumorigenicity of HCC cells. Ectopic expression of CD24 reversed the suppression of tumorigenicity when these HCC cells had been ectopically expressing miR-200b. Clinically, miR-200b downregulation was coupled with ZEB1 upregulation in approximately two-thirds of HCC patients. ZEB1 expression was positively correlated with CD13 and CD24 expressions, while EpCAM expression was positively correlated with miR-200b expression in HCCs.

Conclusions: The miR-200b-ZEB1 circuit is a master regulator of diverse stemness of HCC, which distincts HCCs into those containing CD13+/CD24+ CSCs from those containing EpCAM+ CSCs, and a thus potential target for anti-HCC therapy.

Citation Format: Sen-Yung Hsieh, Su-Chun Tsai. The miR-200b-ZEB1 circuit regulates diverse stemness of human 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 2882. doi:10.1158/1538-7445.AM2017-2882