MicroRNA-181a inhibits autophagy by targeting Atg5 in hepatocellular carcinoma.

Available evidence suggests that autophagy may serve as a tumor suppressor in cases of chronic liver disease and liver cirrhosis and that autophagic deficiency may lead to hepatocellular carcinoma (HCC). Recent studies suggested that the development of several tumor types could be regulated by microRNA-181a. However, the role of miR-181a in the autophagy of HCC remains unclear. In this study, we aimed to investigate the role of miR-181a in the autophagy of HCC. We found that the mRNA expression of miR-181a is higher but the level of autophagy is lower in human HCC compared to normal liver tissue. A luciferase assay confirmed that Atg5 is the target gene of miR-181a. Moreover, the results showed that an miR-181a sponge increased apoptosis in HepG2 cells and reduced the growth of tumors in a HepG2 cell xenograft tumor model. In conclusion, these results suggest that miR-181a can inhibit autophagy in HCC by targeting Atg5, resulting in decreased apoptosis of HCC cells and increased tumor growth.