Effects of mTOR siRNA and Rapamycin on mTOR and 4EBP1 Expressions in Human HeLa Cells

Objective To explore the relationship between mTOR protein and cervical carcinoma development process，and the effects of rapamycin and mTOR siRNA on mTOR and 4EBP1 expressions in cervical carcinoma cells. Methods The expressions of mTOR protein were detected by immunohistochemistry in tissues of normal cervical squamous epithelium, cervical intraepithelium neoplasm(CIN) and cervical carcinoma. In situ hybridization and immunohistochemistry were used respectively to analyze the expressions of mTOR, 4EBP1 mRNA and protein in HeLa cells before and after treatment with rapamycin or RNAi. Results The positive expressions of mTOR protein in 30 cases of normal cervical epithelium, 20 cases of CIN and 45 cases of cervical carcinoma were 36.7% ( 11/30 ), 55% ( 11/20 ) and 71.1% ( 32/45 ), respectively. And there were a signifi cantly higher levels of mTOR protein expression in cervical carcinoma than those in normal cervical squamous epithelium and CIN ( P <0.05 ). Compared with the control group, the expressions of mTOR, 4EBP1 mRNA and protein in HeLa cells were signifi cantly downregulated after treatment at three different concentrations of rapamycin or mTOR siRNA for 24, 48 and 72 h( P <0.05 ). Conclusion The overexpression of mTOR protein may be related with the occurrence and development of cervical carcinoma. Rapamycin and mTOR siRNA could inhibit the expressions of mTOR mRNA, protein and corresponding downstream molecule 4EBP1in cervical carcinoma cells.