miR-26a promoted by interferon-alpha inhibits hepatocellular carcinoma proliferation and migration by blocking EZH2.

BACKGROUNDS: Interferon (IFN)-α has been used to treat hepatocellular carcinoma (HCC). Here, we report that the IFN-α-induced microRNA-26a (miR-26a) can inhibit HCC proliferation and invasion by suppressing enhancer of zeste homologue 2 (EZH2) expression in tumor cells. MATERIALS AND METHODS: First, the miR-26a transcription level was quantified by real-time quantitative PCR in the HCC specimens from IFN-α-treated HCC patients. Next, we transfected HepG2 cells with miR-26a mimics and miR control, and then we investigated the influence of miR-26a mimic transfection on HepG2 cell proliferation and invasion. RESULTS: It was shown that there was increased miR-26a accompanied with downregulated EZH2 expression in the HCC specimens, and EZH2 mRNA levels were inversely correlated with miR-26a expression. There was a dose-response correlation between the IFN-α dosage and EZH2 expression. In addition, the miR-26a mimic transfection decreased the EZH2 expression level significantly in the transfected HepG2 cells and inhibited HepG2 cell proliferation and invasion effectively. CONCLUSION: Our results indicate that miR-26a exerts growth inhibition in HCC and that its inhibitory effect is mediated briefly by blocking EZH2 expression.