Musashi 2 contributes to the sternness and chemoresistance of liver cancer stern cells via LIN28A activation

Accumulating evidence suggests that cancer stem cells (CSCs), a small subset of cancer cells, are responsible for tumor initiation, progression, relapse and metastasis. Musashi 2 (MSI2), a RNA-binding protein, was proposed to be a potent oncogene playing key roles in myeloid leukemia and gastrointestinal malignancies. However, it remains elusive how MSI2 regulates stem cell features in HCC. Herein, we demonstrated that MSI2 was highly expressed in liver CSCs. Overexpression or knockdown of MSI2 altered CSC-related gene expression, self-renewal as well as resistance to chemotherapy in HCC cell lines. In mouse xenograft models, MSI2 could markedly enhance tumorigenicity. Mechanistically, over expression of MSI2 resulted in the upregulation of Lin28A. Sternness and chemotherapeutic drug resistance induced by MSI2 overexpression were dramatically reduced by Lin28A knockdown. Moreover, MSI2 and LIN28A levels positively correlated with the clinical severity and prognosis in HCC patients. In conclusion, MSI2 might play a crucial role in sustaining sternness and chemoresistance of liver CSC5 via LIN28A-dependent manner in HCC. Our findings revealed that MSI2 and Lin28A might be used as potential therapeutic targets for eradicating liver CSC5. (C) 2016 Published by Elsevier Ireland Ltd.