pcDNA3.1-mTOR质粒体外转染对乳腺癌细胞生长的影响

摘要

Objective To investigate the effect of mTOR signal transduction pathway and down-regulating anti-oncogene PTEN on the growth of breast cancer MCF-7 cells. Methods MCF-7 cells were transfected with the eukaryotic expression plasmid pcDNA3.1-mTOR and non-loaded plasmid, and the expression of mTOR in the cells was detected using Western blotting. Flow cytometry was used to analyze apoptosis and cell cycle of the transfected cells, and the expression of PTEN was detected after transfection. Results The cells transfected with pcDNA3.1-mTOR showed a increased growth rate than those transfected with the non-loaded plasmid and those without transfection. The expression of the protein PTEN decreased obviously in the cells after mTOR trasnfection. Conclusion mTOR can regulate the expression of PTEN via PI3K/AKT/PTEN pathways through a negative feedback mechanism. Increased mTOR expression promotes MCF-7 cell growth, suggesting the potential value of mTOR specific inhibitor in the treatment of breast cancer.%目的：研究信号转导通路mTOR体外对乳腺癌MCF-7细胞生长的抑制作用，及对抑癌基因PTEN的负反馈调节的影响。方法用pcDNA3.1-mTOR真核表达质粒及空载质粒转染MCF-7；Western blot检测转染后mTOR蛋白的表达；流式细胞技术检测细胞周期和细胞凋亡情况；检测转染后PTEN蛋白的表达。结果转染组细胞的生长速度明显增快，而未转染组和转染空载体质粒组无明显变化。转染mTOR基因后，PTEN蛋白的表达明显下降。结论 mTOR可能通过PI3K/AKT/PTEN与mTOR信号转导通路负反馈调节PTEN的表达。mTOR的增高可促进乳腺癌细胞的生长，为mTOR的特异性的抑制剂的运用提供了理论证据。