miR-429 represses cell proliferation and induces apoptosis in HBV-related HCC.

MicroRNAs are a class of endogenous non-coding RNAs that regulate gene expression at post-transcriptional level, thus participating in diverse biological pathways. Increasing miRNAs are found to dysregulate hepatocellular carcinoma (HCC) and are involved in liver tumorigenesis. In this study, miR-429 was found to obviously downregulate much more in hepatitis B virus (HBV)-related hepatocellular carcinoma. To evaluate the effects of miR-429, miR-429 was over-expressed in HepG2.2.15 cells. The results have proved that overexpression of miR-429 decreased cell proliferation and induced cell apoptosis. Further, overexpression of miR-429 can suppress the secretion of HBsAg and HBeAg. In concordance to this, the level of NOTCH1 expression was high in human HBV-related HCC tissues and HepG2.2.15 cells. MiR-429 directly targeted NOTCH1 and reduced both mRNA and protein levels of NOTCH1 which stimulated proliferation and suppressed apoptosis in HCC cells. Our results provide new insight into the function of miR-429 in HBV-related HCC. It is beneficial to insight into the mechanism of HBV infection and pathophysiology of HBV-related HCC.