Increased polycomb-group oncogene Bmi-1 expression correlates with poor prognosis in hepatocellular carcinoma

J Cancer Res Clin Oncol. 2008 May;134(5):535-41. doi: 10.1007/s00432-007-0316-8. Epub 2007 Oct 5.

Abstract

Purpose: Recent studies have identified polycomb-group gene Bmi-1 as oncogene in the generation of mouse pre-cell lymphomas, and overexpression of Bmi-1 has been found in several human tumor with the disease progress and poor prognosis of the cancer patients.

Methods: In present study, we investigated Bmi-1 expression and its prognostic significance in hepatocellular carcinoma (HCC) by performing immunohistochemical analysis, using a total of 137 HCC clinical tissue samples.

Results: High Bmi-1 expression (Bmi-1 2+ or 3+) was shown in 29.9% cases. The positive immuno-staining of Bmi-1 was not only in well/moderately-differentiated tumor cells, but also in surrounding noncancerous or cirrhotic liver tissue. Bmi-1 expression level did not correlate with any clinicopathological parameters. However, survival analysis showed that the high-Bmi-1 group had a significantly shorter overall survival time than the low-Bmi-1 group (P=0.047). Multivariate analysis after 24 months revealed that Bmi-1 expression was a significant and independent prognostic parameter (P=0.002) for HCC patients.

Conclusions: Our study indicated that Bmi-1 could be a candidate biomarker for long-term survival in HCC.

MeSH terms

  • Biomarkers, Tumor / analysis*
  • Blotting, Western
  • Carcinoma, Hepatocellular / metabolism*
  • Carcinoma, Hepatocellular / mortality
  • Carcinoma, Hepatocellular / pathology
  • Female
  • Gene Expression
  • Humans
  • Immunohistochemistry
  • Kaplan-Meier Estimate
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / mortality
  • Liver Neoplasms / pathology
  • Male
  • Middle Aged
  • Nuclear Proteins / biosynthesis*
  • Polycomb Repressive Complex 1
  • Prognosis
  • Proto-Oncogene Proteins / biosynthesis*
  • Repressor Proteins / biosynthesis*

Substances

  • BMI1 protein, human
  • Biomarkers, Tumor
  • Nuclear Proteins
  • Proto-Oncogene Proteins
  • Repressor Proteins
  • Polycomb Repressive Complex 1