论文部分内容阅读
[目的]探讨蛋白酶体抑制剂诱导乳腺癌MCF-7细胞凋亡与BAG3蛋白剪切的相互关系,以及BAG3蛋白剪切是否依赖胱天蛋白酶介导完成。[方法]选取人MCF-7乳腺癌细胞系,设空白对照组、MG132处理组、Z-VAD处理组和MG132+Z-VAD联合组。实时定量RT-PCR和Western Blot分别检测各组细胞中BAG3 mRNA和蛋白的表达水平;流式细胞仪检测细胞凋亡。[结果]MG132诱导乳腺癌细胞凋亡过程中BAG3基因和蛋白表达均增高(P<0.05),但BAG3蛋白剪切体也随之增加,流式细胞术结果证明细胞凋亡率增高(P<0.05)。同时,应用胱天蛋白酶体抑制剂Z-VAD处理细胞后,BAG3蛋白剪切体消失。[结论]蛋白酶体抑制剂可诱导上调乳腺癌MCF-7细胞中BAG3基因和蛋白的表达,但BAG3蛋白裂解增强,可导致细胞凋亡增加,这一效应可能依赖胱天蛋白酶介导完成。
[Objective] To investigate the correlation between proteasome inhibitor-induced apoptosis of breast cancer MCF-7 cells and BAG3 protein cleavage and whether BAG3 protein cleavage is dependent on caspase-mediated cleavage. [Method] The human MCF-7 breast cancer cell line was selected. The blank control group, MG132 treatment group, Z-VAD treatment group and MG132 + Z-VAD combined group were established. Real-time quantitative RT-PCR and Western Blot were used to detect the expression of BAG3 mRNA and protein in each group, and the apoptosis was detected by flow cytometry. [Result] The expression of BAG3 gene and protein in MG132 cells was significantly increased (P <0.05), but the amount of BAG3 protein was also increased. The results of flow cytometry showed that the rate of apoptosis increased (P < 0.05). Meanwhile, the BAG3 protein spliced body disappeared after the cells were treated with the Z-VAD, a caspase inhibitor. [Conclusion] The proteasome inhibitor can upregulate the expression of BAG3 gene and protein in breast cancer MCF-7 cells. However, enhanced BAG3 protein cleavage may result in increased apoptosis, which may be mediated by caspase-mediated activation.