Prognostic significance of miR-218 in human hepatocellular carcinoma and its role in cell growth

Oncol Rep. 2014 Oct;32(4):1571-7. doi: 10.3892/or.2014.3386. Epub 2014 Aug 7.

Abstract

MicroRNA-218 (miR-218) is considered a tumor suppressor in human cancer. In the present study, miR-218 expression was found to be significantly lower in human hepatocellular carcinoma (HCC) than in normal tumor-adjacent tissues. miR-218 was clearly silenced or downregulated in five HCC cells (HepG2, Hep3B, SMMC-7721, Huh7 and Bel-7402) compared with normal hepatocytes (LO2). The low expression of miR-218 conferred a poor 5-year survival in HCC patients. Multivariate Cox regression analysis indicated that miR-218 was an independent prognostic factor in HCC. Ectopic expression of miR-218 inhibited proliferation and promoted apoptosis in HepG2 and SMMC-7721 cells. In tumor bearing mice, miR-218 slowed down tumor growth by inducing apoptosis and growth arrest. Restoring miR-218 expression resulted in downregulation of B lymphoma Mo-MLV insertion region 1 homolog (BMI-1) mRNA and protein level in HepG2 and SMMC-7721 cells. In addition, BMI-1 mRNA expression in HCC was significantly higher than that in non-cancerous tissues. BMI-1 mRNA was inversely correlated with miR-218 expression in HCC tissues. In conclusion, miR-218 may serve as a prognostic biomarker and induce apoptosis and growth arrest by downregulating BMI-1 in HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / surgery
  • Cell Line, Tumor
  • Cell Proliferation / genetics*
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Hep G2 Cells
  • Hepatectomy
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / surgery
  • Male
  • Mice
  • Mice, Nude
  • MicroRNAs / genetics*
  • Middle Aged
  • Neoplasm Transplantation
  • Polycomb Repressive Complex 1 / genetics*
  • Polycomb Repressive Complex 1 / metabolism
  • Prognosis
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • BMI1 protein, human
  • MIRN218 microRNA, human
  • MicroRNAs
  • Polycomb Repressive Complex 1