Mfn2基因过表达对人乳腺癌MCF-7细胞增殖及EGFR、EGF蛋白表达的影响

Effects of Mfn2 Gene Overexpression on Proliferation of Human Breast Cancer MCF-7 Cells and Expression of EGFR and EGF

目的通过使人乳腺癌MCF-7细胞过表达线粒体融合素基因-2(Mfn2),研究外源性Mfn2基因对MCF-7细胞增殖及对表皮生长因子受体(EGFR)、表皮生长因子(EGF)蛋白表达的影响。方法实验分为对照组、转染空质粒pEGFP-N1组、转染Mfn2质粒的pEGFP-Mfn2组。转染48h后,检测各组细胞的转染效率、Mfn2mRNA及Mfn2蛋白表达。检测各组MCF-7细胞增殖情况、各组MCF-7细胞周期分布情况。同时检测各组EGFR及EGF蛋白表达情况。结果转染48h后pEGFP-N1组及pEGFP-Mfn2组转染效率分别为(49.15±2.04)%及(51.10±2.18)%,高于对照组[(0.58±0.21)%,P<0.05];pEGFP-Mfn2组的Mfn2mRNA及Mfn2蛋白表达均显著高于对照组及pEGFP-N1组(P<0.05);pEGFP-Mfn2组MCF-7细胞增殖抑制率显著高于其余两组(P<0.05),细胞周期主要阻滞于G0/G1期;pEGFP-Mfn2组EGFR和EGF蛋白表达水平显著低于其余两组(P<0.05)。结论 Mfn2基因过表达可显著抑制MCF-7细胞增殖,其机制可能与Mfn2基因过表达导致了EGFR及EGF表达下调有关。

Objective To investigate the effect of exogenous Mfn2 gene on cell proliferation and the expression of epidermal growth factor receptor （EGFR） and epidermal growth factor （EGF） through overexpressing of mitoehondrial fusion gene-2 （Mfn2） in human breast cancer MCF-7 cells. Methods Control group, pEGFP-N1 group （empty plasmid） and pEGFP-Mfn2 group （transfected with recombinant plasmid pEGFP-Mfn2） was set. About 48 h after transfection the transfeetion efficiencies and expressions of Mfn2 mRNA and Mfn2 protein were determined. MCF-7 cell proliferation and cell cycle distribution of each group was detected. Meanwhile the protein expressions of EGFR and EGF were detected. Results The transfection efficiencies of pEGFP-N1 group and pEGFP-Mfn2 group were （49.15±2.04）% and （51.10±2.18）% respectively,which were obviously higher than that of control group [（0.58 ±0. 21）%, P〈0. 051. The protein expressions of EGFR and EGF in pEGFP-Mfn2 group were significantly higher than that of control group and pEGFP-N1 group （P〈0.05）. MCF-7 cells in pEGFP- Mfn2 group showed higher cellular proliferation inhibition rate than the other 2 groups （P〈0.05） and was blocked in the G0/G1 phase. The protein expressions of EGFR and EGF were notably increased in pEGFP-Mfn2 group than in other groups （P〈0.05）. Conclusion Overexpression of Mfn2 gene can significantly inhibit the proliferation of MCF-7 cells and the underlying mechanism may be involved in the down-regulation of protein expressions of EGFR and EGF mediated by Mfn2 overexpression.