毛蕊异黄酮抑制SIRT1促乳腺癌细胞MCF-7凋亡

Calycosin Promotes Apoptosis of Breast Cancer Cells MCF-7 through Inhibiting SIRT1

目的:探讨毛蕊异黄酮促乳腺癌细胞MCF-7凋亡的机制。方法:MTT检测低、中、高(10μM,50μM,100μM)剂量的毛蕊异黄酮对细胞活力的影响;Tunel检测毛蕊异黄酮对细胞凋亡的影响;Western blot检测SIRT1,p53和cleaved caspase-3的蛋白表达;Real-time PCR检测caspase-3 mRNA的表达。结果:毛蕊异黄酮能够剂量依赖性地降低细胞活力,100μM剂量组的毛蕊异黄酮显著地促进肿瘤细胞凋亡并降低SIRT1,增加p53和cleaved caspase-3的蛋白表达。SIRT1抑制剂烟酰胺(Nicotinamide,NAM,300μM)组与毛蕊异黄酮处理组相比显著地抑制SIRT1的蛋白表达,p53和cleaved caspase-3蛋白表达水平进一步增加;SRT1720(SIRT1特异性激动剂)与毛蕊异黄酮共孵育组逆转SIRT1蛋白表达,降低p53和cleaved caspase-3的蛋白水平。结论:毛蕊异黄酮促进肿瘤细胞MCF-7的凋亡,部分可能是通过降低SIRT1的表达水平,从而增加p53和cleaved caspase-3的蛋白表达促进细胞凋亡。

Objective： To explore the apoptotic mechanism of breast cancer cells MCF-7 caused by calycosin（CAL）. Methods：MTT technology was used to detect effects of low, medium and high（10 μM, 50 μM, 100 μM） concentrations of CAL on cell viability.Tunel assay was applied to identify the effects of different dosages of CAL on apoptosis. Western blot technology was used to verify the effects of CAL on apoptotic related proteins SIRT1, p53 and cleaved caspase-3. Real-time PCR was applied to investigate the expression of caspase-3 m RNA level. Results： CAL could decrease cells viability. CAL of 100μM concentration promoted tumor cell apoptosis,decreased protein expression of SIRT1, increased level of p53 and cleaved caspase-3. SIRT1 inhibitor（Nicotinamide, NAM, 300μM）significantly repressed the protein level of SIRT1, increased protein level of p53 and cleaved caspase-3 compared with CAL treated group; SRT1720（SIRT1 specific agonist） reversed the inhibitory effects of CAL on protein level of SIRT1, whereas the protein level of p53 and cleaved caspase-3 were dominantly decreased. Conclusion： CAL can promote MCF-7 cells apoptosis, at least partly due to downregulated protein level of SIRT1, thereby increasing important apoptotic related gene p53 and caspase-3.