CPP32在阿霉素诱导的胃癌耐药细胞的凋亡

The function of CPP32 in apoptosis of multidrug-resistance gastric cancer cells

目的探讨耐药细胞和药敏细胞中 caspase-3 mRNA、蛋白的表达以及他们相互之间的关系,试图阐明 caspase-3在诱导耐药细胞凋亡中的作用及意义.方法利用已有的胃癌耐药细胞系 SGC7901/08,通过 RT-PCR 研究 caspase-3的 mRNA 在细胞毒药物处理耐药细胞0h,24h 及药敏细胞0h,6h 时的表达,用 Western-blot 的方法讨论其蛋白在耐药细胞中0h,6h,24h,30h 的表达和药敏细胞中0h,6h,24h 的表达,DNA ladder 检测其特征性凋亡变化.MTT法检测细胞的存活率.结果耐药细胞在0h,24h 和药敏细胞在0h,6h 表达的caspase-3mRNA 无显著性差异,蛋白表达在耐药细胞中在6h 出现微量的表达,在30h 时出现更小片断;药敏细胞在6h 时出现小片断,在24h 出现完全裂解.细胞 DNA 分析表明耐药细胞在30h 出现典型的凋亡谱带;应用了 caspase-3抑制剂后细胞的凋亡延迟.药敏细胞在6h 出现典型的凋亡谱带,应用了抑制剂后也出现凋亡的延迟.结论提高耐药细胞的用药量仍然可以使耐药细胞出现凋亡,而且其凋亡的过程与耐药细胞相同,均有 caspase-3的激活,而抑制了 caspase-3的活性,凋亡的发生可被抑制或是延迟,其差别就在于耐药细胞需要较高的药物诱导浓度.耐药细胞与药敏细胞的凋亡机制从本质上并无显著的不同,其根本的差别可能在于凋亡发生前的诸多因素产生的差异.

AIM To identify the effect and the activity of CPP32 in multidrug resistance cell by comparing the gane expression,protein expression,and the relationship between them.We try to illuminate the effect and the significance of cespees-3 in the apoptosis induced by cheomotherapeutic agents in multidrug resistance cells. METHODS Utilizing the established multidrug resistance cell line,we investigated the mRNA expression of caspese-3 in multidrug resistance cells at Oh,24h;and in drug sensitive cells at 0h,6h by RT-PCR.We determined the protein expression of in multidrug resistance cells at 0h,6h,24h,30h;and in drug sensitive cells at 0h,6h,24h by westem blot.DNA ladder was used to examine the characteristic changes of apeptosis,MTT was performed to get survival rate of cells. RESULTS there are no significant difference between the mRNA expression of the resistant cells at 0h,24h and that of the drug sensitive cells at 0h,6h.Analysis of protein expression showed that there is trace expression in resistant cells at 6h;the small degradation products appears at 30h;the little degradation products appears at 6h in sensitive cells,the cespase-3 protein is splitted completely at 24h.DNA analysis show that the typical apoptotic ladder at 30h in resistant cells;the apoptosis of resistant cells was delayed after the inhibitor was applied.The same was occurred at 6h in sensitive cells. CONCLUSIONS Our results imply that execution of apoptosis is the same in mdr cells and sensitive cells,the only difference between mdr cell and sensitive cell is the concentration of the drug and the time of caspess-3 when they have their effect.