瘦素对乳腺癌MCF-7细胞增殖和凋亡的影响及其作用机制

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、80 μg·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。

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

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