血管内皮生长因子受体启动子驱动双自杀基因联合survivin反义寡核苷酸对结直肠癌细胞及血管内皮细胞的特异性杀伤作用

目的探讨腺病毒介导血管内皮生长因子受体（KDR）启动子驱动的CDglyTK融合基因（AdKDR-CDsbrTK）体系联合survivin反义寡核苷酸（ASODN）对结直肠癌细胞（sw620）及血管内皮细胞（ECV304）的特异性杀伤作用。方法将质粒pAdEasy—KDR-CDglyTK在293细胞内包装、扩增产生重组腺病毒。体外感染表达KDR的SW620、ECV304细胞株，同时用survivin ASODN转染同一细胞株，观察腺病毒的感染效率和ASODN的转染情况。应用RT．PCR和Western印迹检测CDglyTK和survivin基因的表达．MTT法测定两者联合应用对细胞株的杀伤效应和旁观者效应。结果survivin ASODN可转染重组腺病毒感染的细胞，并且两者的转染及感染效率无明显变化。CDglyTK可在SW620、ECV304细胞株高效表达。survivin ASODN可明显降低survivin蛋白表达。各基因治疗组细胞存活率明显低于阴性对照组（P〈0．001）。survivinASODN与AdKDR—CDglyTK基因联用后。随着前药浓度的增加，细胞存活率迅速下降，两者联合作用与单一基因作用相比，差异具有统计学意义（P〈0．05）。但在GCV100μg／ml、5-FC 2000μg／ml时，联合基因治疗组细胞存活率略低于单用AdKDR-CDglyTK，两者间差异无统计学意义（P〉0．05）。Survivin ASODN和AdKDR—CDglyTK联合作用，在前药浓度较低时表现为协同效应，并具有更明显的旁观者效应。结论KDR启动子调控的AdKDR-cDglyTK体系和survivin ASODN基因联合，较单一基因具有更强的特异性杀伤结直肠癌细胞及血管内皮细胞的作用。

Specific killing effects of combination of recombinant adenovirus containing double suicide gene driven by KDR promoter and survivin antisense oligonucleotide on colorectal cancer cells and vascular endothelial cells

OBJECTIVE: To evaluate the specific killing effects of combination of recombinant adenovirus mediated double suicide gene driven by KDR promoter and survivin antisense oligonucleotide(ASODN) on colorectal cancer cells and vascular endothelial cells. METHODS: The 293 packaging cells were transfected with the plasmids of pAdEasy-CDglyTK and the recombinant adenovirus were generated. The KDR expressive cells of SW620, ECV304 were infected with adenovirus, meanwhile survivinASODN was transferred into the same cells. The infection rate of adenovirus and transfection efficiency of survivinASODN were observed and the expression of CDglyTK was detected by RT-PCR. The expression of survivin was measured by Western blot. The killing effects and bystander effects on SW620, ECV304 were examined through MTT method. RESULTS: The cells which were infected with the adenovirus mediated double suicide gene could be transfected with the survivin ASODN and the infection rate was not affected as well as the transfection efficiency. The high expression of CDglyTK gene was found in SW620, ECV304 cells infected with recombinant adenovirus and survivin ASODN decreased the survivin protein level. The survival rate of gene therapy group was significantly lower than that of negative group. The combination of survivin ASODN and AdKDR-CDglyTK gene therapy showed significantly lower survival rate of SW620 and ECV304 cells as compared with the AdKDR-CDglyTK or survivin ASODN used alone (P<0.05). The survival rate was slightly lower in GCV 100 microg/ml, 5-FC 2000 microg/ml than that AdKDR-CDglyTK used alone (P>0.05). The combined therapy of AdKDR-CDglyTK and survivin ASODN showed synergistic killing efficacy and more significant bystander effects. CONCLUSION: The combined gene therapy of AdKDR-CDglyTK system and survivin ASODN has stronger specific killing effects on colorectal cancer cells and vein endothelial cells.