瘦素对乳腺癌MCF-7细胞增殖和凋亡的影响及其作用机制

Effects of leptin on proliferation and apoptosis of breast carcinoma MCF-7 cells and its mechanism

目的:研究瘦素对乳腺癌MCF-7细胞增殖和凋亡的影响,并探讨其作用机制。方法:选取处于对数生长期的MCF-7细胞,随机分为对照组和20、40、80μg·L-1瘦素处理组。CCK8试剂盒检测各组MCF-7细胞增殖率;流式细胞术检测各组MCF-7细胞凋亡率;RT-PCR和Western blotting法分别检测各组MCF-7细胞bcl-2和bax的mRNA和蛋白表达水平;在抗凋亡作用的信号通路筛选实验中采用Western blotting法检测不同信号通路抑制剂处理组MCF-7细胞p-AKT和bcl-2的蛋白表达水平。结果:与对照组比较,不同剂量瘦素处理组MCF-7细胞增殖率升高(P<0.05),且呈剂量依赖性,不同剂量瘦素组之间比较差异也有统计学意义(P<0.05);随着瘦素作用剂量增加,不同剂量瘦素处理组细胞凋亡率逐渐降低,与对照组比较差异有统计学意义(P<0.05);与对照组比较,不同剂量瘦素处理组MCF-7细胞bcl-2 mRNA和蛋白表达水平增加(P<0.05),bax mRNA和蛋白表达水平降低(P<0.05);与瘦素组比较,PI3K-AKT信号通路抑制剂LY294002处理组MCF-7细胞的p-AKT和bcl-2蛋白表达水平明显下降(P<0.05)。结论:瘦素对乳腺癌MCF-7细胞有促进增殖和拮抗凋亡的作用,其抗凋亡效应与通过细胞信号通路PI3K-AKT促进bcl-2表达有关。

Objective To observe the effects of leptin on the proliferation and apoptosis of the breast carcinoma MCF-7cells,and to explore the mechanism.Methods The MCF-7cells at logarithm growth phase were selected and randomly divided into control group and different doses（20,40,80μg· L^-1）of leptin groups.The proliferation rates of the MCF-7cells in various groups were determined by CCK8 assay kit;the apoptotic rates of the MCF-7cells in various groups were analyzed by flow cytometry;the mRNA and protein expressions of bcl-2and bax of the MCF-7cells in various groups were detected by RT-PCR and Western blotting methods;the protein expressions of p-AKT and bcl-2in the MCF-7cells in different cell signaling pathway inhibitor treatment groups were tested by Western blotting method.Results Compared with control group,the proliferation rates of the MCF-7cells in leptin groups were increased in a dose-dependent manner（P〈0.05）;the apoptotic rates of the MCF-7cells in leptin groups were decreased（P〈0.05）;the mRNA and protein expression levels of bax in the MCF-7cells in leptin groups were decreased（P〈0.05）,and the mRNA and protein expression levels of bcl-2were increased（P〈0.05）;compared with leptin group,the protein expressions of p-AKT and bcl-2in PI3K-AKT inhibitor LY294002 group were markedly decreased（P〈0.05）.Conclusion Leptin can increase the proliferation and inhibit the apoptosis of breast carcinoma MCF-7cells,and the mechanism of anti-apoptosis may be releted to the up-regulation of bcl-2via PI3K-AKT signaling pathway.