Correlations of BMI-1 expression and telomerase activity in ovarian cancer tissues.
OBJECTIVE
To investigate the correlation between oncoprotein Bmi-1 and telomerase activity in ovarian cancer tissues.


METHODS
SP immunohistochemistry was adopted to detect the expression of Bmi-1 protein in tissues of 47 ovarian epithelial cancer cases. Modified telomeric repeat amplification protocol (TRAP, silver staining technique) was used to detect the telomerase activity.


RESULTS
While in 80.85% (38/47) of ovarian epithelial cancer cases Bmi-1 protein was overexpressed, 46.81% (22/47) had very strong expression level. Bmi-1 expression levels in ovarian carcinoma tissue differ depending on tissue grade (higher for G3 cancer cases- 93.10% than for grade G2 cases - 61.11%) and the stage of the disease (lower for phase II and phase III cases - 66.67% than for phase IV cases- 92.31%). In ovarian epithelial cancer tissues, 87.23% (41/47) demonstrated positive telomerase activity in contrast to zero activity in normal tissues. Majority (90.24%) of specimens with positive telomerase activity possessed high Bmi-1 expression levels. Spearman correlation analysis indicated that expression of Bmi-1 protein was positively correlated with the elevated telomerase activity.


CONCLUSIONS
Bmi-1 protein is highly expressed in ovarian epithelial cancer tissues, and its expression level correlates with histological grade and clinical phase of the patients. Elevation of Bmi-1 expression is closely correlated to the increased telomerase activity.
Zhang
F
F
Affiliated Oncology Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
Sui
L
L
Xin
Tao
T
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D009687:Nuclear Proteins / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology; D063150:Polycomb Repressive Complex 1; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D019098:Telomerase / Q000378:metabolism*; D015854:Up-Regulation
C069077:BMI1 protein, human; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1; D019098:Telomerase