Smac基因过表达对白血病耐药细胞株K562/AO2化疗敏感性的影响

Overexpression of Smac gene enhanced chemotherapeutic sensitivity of K562/A02 to daunorubicin

目的 探讨Smac基因过表达对K562/A02细胞株化疗敏感性的影响.方法 构建重组腺病毒载体pAdeno-Smac,转染K562/A02细胞.实验分组：A组：pAdeno-Smac转染组;B组：空载体转染对照组;C组：正常对照组.Western blot检测转染前后细胞内Smac蛋白的表达水平.将终浓度分别为0、0.5、1.0、1.5 mg/L的柔红霉素处理各组后,Annexin V/PI双染法经流式细胞仪检测各组细胞早期凋亡率.结果 成功构建腺病毒载体pAdeno-Smac质粒.Western blot结果证实,经Smac基因全长cDNA转染后,K562/A02细胞中的Smac蛋白表达显著升高.经不同浓度柔红霉素处理后,A组的细胞早期凋亡率明显高于B组和C组,组间比较差异有统计学意义（P＜0.05）,且随着柔红霉素浓度的升高,细胞凋亡率随之升高,B组和C组之间差异无统计学意义.结论 重组腺病毒载体pAdeno-Smac可通过使K562/A02细胞中的Smac蛋白表达增高,增强细胞对化疗药物的敏感性.

Objective To investigate the effects of Smac gene overexpression on chemotherapeutic sensitivity of K562/A02 to daunorubicin. Methods The expression adenovirus of Smac gene was construc- ted to be transfected into human leukemia multidrug resistance cell line K562/A02. The experimental group as follows：group A was pAdeno-Smac transfected group,group B was empty vector transfected control group, group C was normal control group. The cellular Smac gene expression were determined by Western blotting. Different concentrations of daunorubicin（ the final concentration were respectively 0,0.5,1.0,1.5 mg/L） were treated each group. The early apoptosis was determined by Annexin V/PI. Results We successfully constructed the recombinant adenovirus vector plasmid pAdeno-Smac. Compared with the group B and C, the Smac expression level of group A was significantly increased（ P 〈 0.05 ）. When the final concentration of dauno-rubicin were 0 mg/L,the apoptosis rate of each group was no signifycant differences. When the final concentration of daunorubicin were 0.5,1.0 and 1.5 rag/L, compared with group B and C, the early apoptosis rate of group A was significantly increased after the treatments of daunorubicin, the difference were significant（P 〈 0.05 ）. Additionally, the early apoptosis rate of group A was significantly increased with the concentration o daunorubicin increased（P 〈 0.05 ）. The difference between group B and C were not significant. Conclusion The recombinant adenovirus vector plasmid pAdeno-Smac could increase the expression of Smac protein in K562/A02 cells. Smac gene overexpression could increase chemotherapeutic sensitivity of K562/A02 to daunorubicin.