OncomiR miR-96 and miR-182 promote cell proliferation and invasion through targeting ephrinA5 in hepatocellular carcinoma

EphrinA5, a member of the ephrinA subclass, is downregulated in hepatocellular carcinoma (HCC) and acts as a tumor suppressor. However, the upstream regulation mechanism of ephrinA5 remains unclear. In this study, we tried to identify and characterize the roles of miR-96 and miR-182 in the regulation of ephrinA5 expression in HCC. The expression levels of miR-96 and miR-182 were examined in 47 paired HCC and para-tumoral liver tissues using quantitative real-time RT-PCR. The luciferase reporter assay and western blotting were employed to dissect the association between miR-96/182 and ephrinA5 expression. Moreover, cells were treated with synthetic miR-96/182 precursors and inhibitors to assess their effects on HCC cell growth and migration. It was found that both miR-96 and miR-182 were upregulated in HCC compared to para-tumoral normal tissues. The expression of miR-96 and miR-182 was inversely associated with ephrinA5 protein levels. Furthermore, both miR-96 and miR-182 directly targeted the 3'UTR of the ephrinA5 mRNA and suppressed protein translation. The suppression of miR-96 and miR-182 led to reduced HCC cell proliferation and migration by negatively regulating ephrinA5 expression. In conclusion, miR-96 and miR-182 may act as oncomiRs in HCC by suppressing the expression of ephrinA5 and may play important roles in hepatocarcinogenesis.