【摘要】 目的:研究2种共轭亚油酸(conjugated linoleic acid,CLA)单体——顺9,反11-CLA(cis 9,trans11-CLA,c9,t11-CLA)和反10,顺12-CLA(trans10,cis12-CLA,t10,c12-CLA)诱导乳腺癌细胞MCF-7凋亡及其作用机制。方法:采用MTT法检测CLA对MCF-7细胞的生长抑制作用,锥虫蓝染色绘制CLA作用后MCF-7细胞的生长曲线;荧光显微镜观察及FCM检测MCF-7细胞的凋亡和细胞周期的改变;RT-PCR和Western印迹法检测MCF-7细胞PPARγ、Bcl-xL和Bcl-xS mRNA以及PPARγ、Bcl-2、Bax和caspase-3的蛋白表达。结果:2种CLA单体均可抑制MCF-7细胞增殖并诱导细胞凋亡,与对照组相比差异有统计学意义(P<0.05);RT-PCR和Western印迹法检测结果显示,2种CLA单体均可以提高PPARγ、Bcl-xS mRNA和PPARγ、Bax、caspase-3蛋白的表达,降低Bcl-xL mRNA和Bcl-2蛋白的表达,与对照组比较差异有统计学意义(P<0.05);且2种CLA单体对PPARγ与凋亡相关蛋白Bax、Bcl-2和caspase-3的表达影响呈剂量和时间依赖性及同步相关性。结论:c9,t11-CLA和t10,c12-CLA对乳腺癌MCF-7细胞具有抑制生长和促凋亡的作用,CLA可能作为PPARγ的配体通过激活PPARγ-Bcl-2-caspase-3细胞凋亡信号通路而实现抑制肿瘤细胞生长的作用。更多还原

【Abstract】 Objective:To study the effects of two kinds of conjugated linoleic acid(CLA),cis 9,trans 11-CLA and trans 10,cis 12-CLA in inducing apoptosis of breast cancer MCF-7 cells and the action mechanism.Methods:The inhibitory effect of CLA on proliferation of MCF-7 cells was assessed by MTT assay.Trypan blue staining was used to investigate the growth of MCF-7 cells.Hoechst 33342 fluorescence microscopy and flow cytometry were used to detect the apoptosis of MCF-7 cells and cell cycle distribution.The mRNA transcriptions of PPARγ(peroxisome proliferators activated receptor γ),Bcl-xL,and Bcl-xS were determined by RT-PCR.The protein expressions of PPARγ,Bcl-2,Bax,and caspase-3 were detected by Western blot.Results:Two kinds of CLA isomers could inhibit cell proliferation and induce apoptosis.The difference was significant compared with control group(P<0.05).c 9,t11-CLA and t10,c12-CLA increased the PPARγ and Bcl-xS mRNA transcription and PPARγ,Bax,and caspase-3 protein expression(P<0.05) and decreased Bcl-xL mRNA and Bcl-2 protein expressions.The difference was significant compared with control group(P<0.05).The effects of c 9,t11-CLA and t10,c12-CLA on the expression of PPARγ and apoptosis-related proteins Bax,Bcl-2,and caspase-3 were in dose-and time-dependent manners and had concurrent correlations.Conclusion:c 9,t11-CLA and t10,c12-CLA could inhibit MCF-7 cells proliferation and induce apoptosis.CLA may serve as a PPARγ ligand and exert its anti-tumor effects by activating PPARγ-Bcl-2-caspase-3 apoptotic signaling pathway.更多还原