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目的:评估茶多酚对人乳腺癌细胞MCF-7凋亡的影响,并探讨了其作用机制。创新点:全面考察了茶多酚对抗乳腺癌的分子机制,为茶多酚作为抗肿瘤辅助药物提供理论依据。方法:首先选取不同组织来源的五种人肿瘤细胞(人肝癌细胞Hep G2、人肺癌细胞A549、人前列腺癌细胞PC3、人宫颈癌细胞Hela、人乳腺癌细胞MCF-7)作为体外模型,以MTT法检测茶多酚对其增殖抑制作用。然后,选用最敏感细胞MCF-7为研究对象,采用流式细胞术检测茶多酚对细胞周期分布的影响,用Hoechst 3328染色法观察茶多酚对细胞核形态的影响,用JC-1染色法观察茶多酚对细胞线粒体跨膜电位的影响,用双氯荧光素(DCFH-DA)染色法观察茶多酚对细胞活性氧(ROS)水平的影响,用凝胶电泳DNA片段测定法(DNA ladder)观察茶多酚处理后细胞DNA断裂情况,用蛋白质印迹法(Western blot)检测茶多酚对细胞凋亡关键蛋白caspase-3和caspase-9表达的影响,全面探讨了茶多酚体外抗肿瘤机制。结论:实验结果显示,茶多酚能够通过诱导细胞周期阻滞和线粒体凋亡抑制MCF-7细胞增殖。茶多酚诱导线粒体凋亡的途径是使线粒体跨膜电位下降,促使MCF-7细胞内ROS生成,促使细胞DNA断裂和促进细胞内caspase-3和caspase-9的活化。
Objective: To evaluate the effect of tea polyphenols on the apoptosis of human breast cancer cell line MCF-7 and to explore its mechanism. Innovation: a comprehensive study of the molecular mechanism of tea polyphenols against breast cancer, tea polyphenols as anti-tumor drugs to provide a theoretical basis. METHODS: Five human tumor cells (Hep G2, A549, PC3, Hela and MCF-7) from different tissues were selected as an in vitro model Inhibitory effect of tea polyphenols on proliferation by MTT assay. Then, the most sensitive cell MCF-7 was selected as the research object, the effect of tea polyphenols on the cell cycle distribution was detected by flow cytometry. The effect of tea polyphenols on the nuclear morphology was observed by Hoechst 3328 staining. The effect of tea polyphenols on mitochondrial transmembrane potential was observed. The effect of tea polyphenols on reactive oxygen species (ROS) level was observed by DCFH-DA staining. ladder was used to observe the DNA fragmentation in tea polyphenols. The effects of tea polyphenols on the expression of caspase-3 and caspase-9 were detected by Western blot. Tumor mechanism. Conclusion: The experimental results show that tea polyphenols can inhibit MCF-7 cell proliferation by inducing cell cycle arrest and mitochondrial apoptosis. The pathway of tea polyphenols to induce mitochondrial apoptosis is to decrease the transmembrane potential of mitochondria, promote the generation of ROS in MCF-7 cells, promote the DNA breakage and promote the activation of caspase-3 and caspase-9.