【摘要】 目的:本实验通过阻断caspase-3途径,观察长春碱诱导的肿瘤细胞凋亡及胞浆内IκΒ-α蛋白降解的影响,以探索长春碱诱导肿瘤细胞凋亡的信号转导途径。方法:用二甲基亚砜对照、100μmol/L caspase-3抑制剂(DEVD-CHO)预处理乳腺癌Bcap37细胞3h后,加入不同浓度的长春碱,以MTT法检测肿瘤细胞增殖能力,以细胞DNA片段分析及PI染色法检测肿瘤细胞凋亡,以蛋白免疫印迹法检测pro-caspase-3和IκΒ-α蛋白的变化。结果:蛋白免疫印迹法证实长春碱可诱导pro-caspase-3蛋白的降解。经MTT法、DNA凋亡梯状条带法及流式细胞仪PI染色法证实,DEVD-CHO能减弱由长春碱所诱导的肿瘤细胞凋亡。两组的IC50分别为56.8μmol/L和87.4μmol/L。蛋白免疫印迹实验表明,DEVD-CHO能抑制由长春碱所诱导的IκΒ-α蛋白磷酸化降解。结论:在长春碱诱导肿瘤细胞凋亡过程中,NF-κΒ/IκΒ信号转导途径起着重要作用,caspase-3途径参与调节。阻断该途径将减弱长春碱所诱导的肿瘤细胞凋亡和IκΒ-α磷酸化降解。更多还原

【Abstract】 AIM:To investigate the changes of apoptosis and activation of IκΒ-α induced by vinblastine via the blockage of caspase-3 signal transduction pathway, and to explore the possible mechanism of signal transduction pathway involving in the vinblastine-induced apoptosis. METHODS: The breast cancer cell lines Bcap37 were treated with different concentrations of vinblatine dissolved in dimethyl sulphoxide (DMSO) or caspase-3 inhibitor (DEVD-CHO, 100 μmol/L) for 3 h. The changes of the proliferation were detected by MTT methods. The apoptosis was determined by observing the internucleosomal DNA cleavage and PI staining, and the proteins of pro-caspase-3 and IκΒ-α were detected by Western blotting methods. RESULTS: The results showed that vinblastine induced the pro-caspase-3 degradation. The significantly attenuation of vinblastine-induced apoptosis in breast cancer cell line by caspase-3 inhibitor DEVD-CHO was verified by MTT assay, internucleosomal DNA cleavage and flow cytometry PI staining analysis. The IC50 was 56.8 μmol/L and 87.4 μmol/L respectively for two groups. The inhibition of vinblastine-induced phosphorylated degradation of IκΒ-α was also observed by DEVD-CHO. CONCLUSION: Based on these finding, vinblastine induces apoptosis in breast cancer cells via NF-κΒ/IκΒ signal transduction pathway, which is co-operated by caspase signal pathway. Through the blockage of caspase pathway with caspase-3 inhibitor, vinblastine-induced apoptosis and the phosphorylated degradation of IκΒ-α in breast cancer cells are suppressed greatly.更多还原