CPP32在耐药细胞中的活性及其意义

目的　探讨耐药细胞和药敏细胞中caspase - 3mRNA、蛋白的表达及相互关系 ,试图阐明caspase - 3在诱导耐药细胞凋亡中的作用。方法　利用胃癌耐药细胞系SGC790 1/ 0 8,通过RT -PCR研究caspase - 3的mRNA在细胞毒药物处理耐药细胞0h ,2 4h及药敏细胞 0h ,6h时的表达 ,用Western -blot检测其蛋白在耐药细胞中 0h ,6h ,2 4h ,30h的表达和药敏细胞中 0h ,6h ,2 4h的表达 ,DNAladder检测其特征性凋亡 ,MTT法检测细胞的存活率。结果　耐药细胞和药敏细胞在 0h ,2 4h表达的caspase- 3mRNA无显著性差异 ,蛋白表达在耐药细胞中 6h有微量表达 ,30h出现更小片断 ;药敏细胞在 6h时出现小片断 ,2 4h完全裂解。细胞DNA分析表明耐药细胞 30h出现典型的凋亡谱带 ;应用了caspase - 3抑制剂后细胞凋亡延迟。药敏细胞 6h出现典型的凋亡谱带 ,应用抑制剂后凋亡延迟。结论　提高耐药细胞用药量仍可以使耐药细胞凋亡 ,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 ,凋亡可被抑制或是延迟 ,其差别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的差别可能在于凋亡发生前的诸多因素产生的差异。

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

Objective To identify the function and the activity of CPP32 in multidrug resistance cell by comparing the gene expression, protein expression, and the relationship between them; try to illuminate the function and the signification of caspase-3 in apoptosis induced by chemotherapeutic agents in multidrug resistance cells. Methods The mRNA expression of caspase-3 in multidrug resistance cells was tested at 0h and 24h and in sensitive cells at 0h and 6h by RT-PCR. The protein expression in multidurg resiseance cells was tested at 0h, 6h, 24h and 30h, and in sensitive cells at 0h, 6h and 26h by westem blot. DNA ladder was used to examine the characteristic changes of apoptosis, MTT was performed to get the detail of the mortality of cells. Results There was no remarkable difference between the mRNA expression in resistant cells at 0h and 24h and in sensitive cells at 0h and 6h. There was trace protein expression in resistant cells at 6h, the small degradation products appeared at 30h; the little degradation products appeared at 6h in sensitive cells, the caspase-3 protein was catalyzed completely at 24h. DNA analysis showed that the typical apoptotic ladder appeared at 30h in resistant cells; the apoptosis of resistant cells was delayed after the special inhibitor applied. The same appearance occurred at 6h in sensitive cells. Conclusion The results imply that execution of apoptosis is the same in mdr cells and sensitive cells, the only difference is the concentration of the drug and the appearing time of the activity of caspase-3.