【摘要】 目的:研究蛋白酶体抑制剂PS341是否可增强他莫昔芬(TAM)诱导的乳腺癌细胞凋亡,并探讨可能的机制。方法:采用MTT方法测定细胞活力,采用流式细胞仪检测细胞凋亡,采用蛋白质印迹法检测Caspase-8的活化,PARP的裂解及死亡受体Fas蛋白的表达。结果:TAM以时间及浓度依赖的方式抑制乳腺癌MCF-7细胞增殖,24及48h的IC50分别为25和6μmol/L,25μmol/L的TAM处理24h可诱导21.9%的MCF-7细胞发生凋亡,10nmol/L的PS341预处理后给予25μmol/L的TAM处理24h细胞凋亡增至34.6%,PS341与TAM均可轻微上调Fas的表达水平,两药联合应用后可显著上调Fas的表达水平,并明显增强线粒体外凋亡通路的活性。结论:PS341与TAM联合应用可通过上调Fas的表达水平,增强TAM诱导的乳腺癌MCF-7细胞凋亡。更多还原

【Abstract】 OBJECTIVE:To investigate the effect of PS341 on tamoxifen-induced apoptosis,and explore the possible mechanism.METHODS: Cells proliferation was measured using MTT assay.Cells apoptosis was determined by flow cytometry.Expression of protein was analyzed by western blot.RESULTS: TAM triggered a time-and dose-dependent inhibition of MCF-7 cells proliferation.The 50% inhibitory concentrations(IC50) at 24 h and 48 h were 25 μmol/L and 6 μmol/L respectively.TAM concentration up to 25 μmol/L induced about 21.9% cells apoptosis.Pretreating with 10 nmol/L PS341 enhanced tamoxifen-induced apoptosis from 21.9% to 34.6%.Western blot analysis showed that tamoxifen or PS341 alone induced only a modest upregulation of Fas.PS341 combined with tamoxifen significantly upregulated the expression of Fas and enhanced the activation of extrinsic apoptosis pathway.CONCLUSION: PS341 can enhanced tamoxifen-induced breast cancer MCF-7 cells apoptosis through upregulating the expression of Fas.更多还原