MicroRNA-761 is upregulated in hepatocellular carcinoma and regulates tumorigenesis by targeting Mitofusin-2

Cancer Sci. 2016 Apr;107(4):424-32. doi: 10.1111/cas.12904. Epub 2016 Mar 30.

Abstract

Hepatocellular carcinoma (HCC) is the sixth most prevalent cancer and the third leading cause of cancer-related deaths worldwide. The fate of a cell is determined by the balance between the processes of fission and fusion that constantly occur in the mitochondria of cells. We previously showed that overexpression of Mitofusin-2 can induce apoptosis in HCC cells by triggering an influx of Ca(2+) into the mitochondria from the ER. The function of Mitofusin-2 has been studied extensively, but the mechanism underlying the post-transcriptional regulation of Mitofusin-2 has not been elucidated. In the present study, we aimed to identify the mechanism of Mitofusin-2 regulation in HCC. We demonstrated that Mitofusin-2 is a direct target of miR-761, which was found to be upregulated in HCC tissues. Furthermore, a miR-761 inhibitor impaired mitochondrial function by upregulating Mitofusin-2 and effectively repressed tumor growth and metastasis both in vivo and in vitro. Our findings provide new insight into the mechanism underlying Mitofusin-2 regulation and the potential role of miR-761 in HCC, making it a potential candidate for use in HCC therapy in the future.

Keywords: Cell proliferation; Mfn2; MiR-761; hepatocellular carcinoma; mitochondria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics
  • Carcinogenesis / genetics*
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / pathology
  • Cell Proliferation / genetics
  • GTP Phosphohydrolases / biosynthesis*
  • GTP Phosphohydrolases / genetics
  • Gene Expression Regulation, Neoplastic
  • Hep G2 Cells
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / pathology
  • MicroRNAs / biosynthesis*
  • MicroRNAs / genetics
  • Mitochondria / metabolism
  • Mitochondrial Proteins / biosynthesis*
  • Mitochondrial Proteins / genetics

Substances

  • MicroRNAs
  • Mitochondrial Proteins
  • microRNA761 microRNA, human
  • GTP Phosphohydrolases
  • MFN2 protein, human