OBJECTIVETo investigate the association of B cell-specific MLV integration site-1 (Bmi-1) mRNA expression level with the differentiation, metastasis and prognosis of gastric carcinoma.

METHODSTissue specimens were obtained from 42 patients undergoing surgery for gastric carcinomas. Reverse transcriptional PCR (RT-PCR) was performed for amplification of Bmi-1 mRNA from the 42 tumor tissues and matched adjacent normal tissues, and the differential Bmi-1 mRNA expression was analyzed for its association with the clinical manifestations of the patients.

RESULTSBmi-1 mRNA expression was detected in all the gastric carcinoma tissues and normal tissues adjacent to the carcinoma using fluorescence method, and in 29 cases, Bmi-1 mRNA expression was significantly higher in the tumor tissues than in the adjacent tissues. Expression of Bmi-1 mRNA was highly correlated with tumor size, lymph node metastasis and T classification (P<0.05), but not with the patients' gender, age, or tumor differentiation (P>0.05). The survival rate was much lower in patients positive for Bmi-1 mRNA expression than in those without Bmi-1 mRNA expression.

CONCLUSIONSBmi-1 mRNA expression is correlated to differentiation and metastasis of gastric carcinoma and may facilitate its prognostic evaluation. Bmi-1 may serve as a marker for assessing the progression of gastric carcinoma and provide assistance for clinical therapeutic decisions.