miR-590-5p suppresses hepatocellular carcinoma chemoresistance by targeting YAP1 expression

Background: Resistance to chemotherapeutic treatment is a common phenomenon in cancers, especially in hepatocellular carcinoma (HCC). The Hippo signaling pathway has been demonstrated to play a role in tumor initiation, development, and progression. However, little is known about its roles in the HCC chemoresistance. Methods: In this study, real-time PCR and western blotting were used to identify the expression profile of key components of Hippo signaling pathway between chemoresistant and chemosensitive HCC cell lines. in vitro and in vivo loss- and gain-of-function studies were performed to reveal the effects and related mechanism of microRNA-590-5p/YAP1 axis in the chemoresistant phenotype of HCC cells. Findings: We identified yes-associated protein 1 (YAP1) as the major dysregulated molecules in adriamycin (ADR)-resistant HCC cells. YAP1 was profoundly implicated in the chemoresistant phenotype of HCC cells. Furthermore, microRNA-590-5p was revealed as a functional modulator of YAP1. Importantly, YAP1-mediated chemoresistant phenotype was closely related to increased expression of stemness markers and ATP-binding cassette transporters. HCC patients with poor response to transarterial chemoembolization (TACE) treatment had higher protein level of YAP1 than that in the responsive patients. Interpretation: The microRNA-590-5plYAP axis plays an important role in the chemotherapeutic resistance of HCC cells, suggesting new adjuvant chemotherapeutic directions in HCC. (C) 2018 The Authors. Published by Elsevier B.V.