鸦胆子苦醇对人乳腺癌MCF-7细胞凋亡的影响

Effects of BRU on Human Breast Cancer MCF-7 Cell Apoptosis

目的观察鸦胆子苦醇(BRU)对人乳腺癌MCF-7细胞凋亡的影响,探讨其作用机制。方法用BRU处理MCF-7细胞。采用CCK-8法和流式细胞术检测MCF-7细胞抑制率和凋亡率,Western blot检测线粒体凋亡通路和内质网应激(ERS)相关蛋白的表达,利用免疫荧光技术实现Nrf2和p53蛋白定位。结果与对照组比较,BRU显著抑制MCF-7细胞增殖,110 nmol/L BRU诱导MCF-7细胞凋亡有时间依赖性。110 nmol/L BRU显著降低Nrf2及下游蛋白表达,显著增加GRP78、p-PERK/PERK、p-e IF2α/e IF2α、ATF4、CHOP、Apaf-1、Bax/Bcl-2、CytochromeC、Cleaved-caspase3、p53和p21蛋白的表达(P<0.05,P<0.01,P<0.001),细胞核Nrf2蛋白含量减少、p53蛋白含量增加。结论 BRU通过诱发ERS,抑制Nrf2蛋白表达和核转移,破坏抗氧化作用,诱导MCF-7细胞凋亡。

Objective To investigate the effects of brusatol(BRU)on apoptosis of human breast cancer MCF-7 cells;To discuss its mechanism of action.Methods MCF-7 cells were treated with BRU.The inhibitory ratio and apoptotic ratio of MCF-7 cells was detected by CCK-8 assay and flow cytometry,respectively.Western blot was used to detect the expression of mitochondrial apoptosis pathway and endoplasmic reticulum stress(ERS)-related protein,and Nff2 and p53 protein localization were achieved by immunofluorescence technique.Results Compared with the control group,BRU could significantly inhibit the proliferation of MCF-7 cells,and 110 nmol/L BRU induced MCF-7 cells apoptosis in a time-dependent manner.110 nmol/L BRU significantly decreased the expression of Nrf2 and downstream proteins,and significantly increased expression of GRP78,p-PERK/PERK,p-eIF2α/eIF2α,ATF4,CHOP,Apaf-1,Bax/Bcl-2,Cytochrome C,Cleaved-caspase3,p53 and p21 proteins(P<0.05,P<0.01,P<0.001).The content of Nrf2 protein decreased and the content of p53 protein increased.Conclusion Through inducing ERS,BRU inhibits Nrf2 protein expression and nuclear transfer,destroys antioxidant activity,and induces apoptosis in MCF-7 cells.