MicroRNA-26a inhibits proliferation and metastasis of human hepatocellular carcinoma by regulating DNMT3B-MEG3 axis

Oncol Rep. 2017 Jun;37(6):3527-3535. doi: 10.3892/or.2017.5579. Epub 2017 Apr 19.

Abstract

miR-26a is known to play an important oncosuppressive role in HCC. However, its regulatory role and relationship with other non-coding RNAs is less clear. In the present study, we report that the expression levels of miR-26a and long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) were frequently downregulated in HCC tissues compared to matched non-malignant tissues. In addition, the expression levels of miR-26a and MEG3 were negatively correlated with the tumor sizes and TNM clinical stage in HCC patients. Overexpression of miR-26a significantly reduced the capacity of proliferation, invasion and migration of HCC cells. Moreover, we demonstrated that DNA methyltransferase 3b (DNMT3B) was a direct target gene of miR-26a. Overexpression of miR-26a suppressed the expression level of DNMT3B. Inhibited expression of DNMT3B showed similar tumor suppressive effects induced by miR-26a upregulation, and resulted in the upregulation of MEG3. Furthermore, we found that the expression levels of DNMT3B were upregulated in the HCC tissues compared with non-malignant tissues, and it was inversely correlated with miR-26a and MEG3 in HCC tissues. Thus, these results provided a plausible link between the observed reduction of miR-26a and MEG3 in HCCs. Together, the present study added miR-26a/DNMT3B/MEG3 axis to the complex mechanisms of HCC development.

MeSH terms

  • Aged
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / pathology
  • Cell Proliferation / genetics
  • DNA (Cytosine-5-)-Methyltransferases / genetics*
  • DNA Methyltransferase 3B
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / pathology
  • Male
  • MicroRNAs / genetics*
  • Middle Aged
  • Neoplasm Metastasis
  • RNA, Long Noncoding / genetics*
  • Signal Transduction

Substances

  • MEG3 non-coding RNA, human
  • MIRN26A microRNA, human
  • MicroRNAs
  • RNA, Long Noncoding
  • DNA (Cytosine-5-)-Methyltransferases