Overexpression of Bmi-1 contributes to the invasion and metastasis of hepatocellular carcinoma by increasing the expression of matrix metalloproteinase (MMP)‑2, MMP-9 and vascular endothelial growth factor via the PTEN/PI3K/Akt pathway

Int J Oncol. 2013 Sep;43(3):793-802. doi: 10.3892/ijo.2013.1992. Epub 2013 Jun 26.

Abstract

Hepatocellular carcinoma (HCC) is one of the most common malignant tumours and it carries a poor prognosis due to a high rate of recurrence or metastasis after surgery. Bmi-1 plays a significant role in the growth and metastasis of many solid tumours. However, the exact mechanisms underlying Bmi-1-mediated cell invasion and metastasis, especially in HCC, are not yet known. In the present study, we sought to evaluate the expression of Bmi-1 in HCC samples and its relationship with clinicopathological characteristics and prognostic value, we also investigated related mechanisms underlying Bmi-1-mediated cell invasion in HCC. Our results showed that Bmi-1 is upregulated in HCC tissues compared to matched non-cancer liver tissues; and its expression is positively associated with tumour size, metastasis, venous invasion and AJCC TNM stage, respectively; multivariate analysis showed that high expression of Bmi-1 was an independent prognostic factor for overall survival. In addition, the shRNA-mediated inhibition of Bmi-1 reduced the invasiveness of two HCC cell lines in vitro by upregulating phosphatase and the tensin homolog deleted on chromosome 10 (PTEN) expression, inhibiting the phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway and downregulating the expression and activities of matrix metalloproteinase (MMP)-2 and MMP-9 and vascular endothelial growth factor (VEGF). These data demonstrate that Bmi-1 plays a vital role in HCC invasion and that Bmi-1 is a potential therapeutic target for HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Carcinoma, Hepatocellular
  • Elafin / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic
  • Hep G2 Cells
  • Humans
  • Liver Neoplasms
  • Male
  • Matrix Metalloproteinase 2 / biosynthesis*
  • Matrix Metalloproteinase 2 / genetics
  • Matrix Metalloproteinase 9 / biosynthesis*
  • Matrix Metalloproteinase 9 / genetics
  • Middle Aged
  • Mitogen-Activated Protein Kinase 7 / biosynthesis*
  • Mitogen-Activated Protein Kinase 7 / genetics
  • Neoplasm Invasiveness / genetics
  • Neoplasm Metastasis / genetics
  • Neoplasm Metastasis / pathology
  • Neoplasm Staging
  • PTEN Phosphohydrolase / genetics
  • PTEN Phosphohydrolase / metabolism
  • Prognosis
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / genetics*
  • Vascular Endothelial Growth Factor A / biosynthesis*
  • Vascular Endothelial Growth Factor A / genetics

Substances

  • Elafin
  • PI3 protein, human
  • Vascular Endothelial Growth Factor A
  • Proto-Oncogene Proteins c-akt
  • MAPK7 protein, human
  • Mitogen-Activated Protein Kinase 7
  • PTEN Phosphohydrolase
  • PTEN protein, human
  • MMP2 protein, human
  • Matrix Metalloproteinase 2
  • Matrix Metalloproteinase 9