KDR启动子驱动双自杀基因靶向杀伤人胃癌细胞的作用

Adenovirus-mediated double suicide gene driven by KDR promoter selectively kills human gastric adneocarcinomacell line SGC7901

目的:探讨腺病毒介导KDR启动子驱动的双自杀基因体系对人胃癌细胞SCG7901的靶向杀伤作用.方法:应用重组腺病毒AdEasy-KDR-CDglyTK体外感染实验组SCG7901细胞株和对照组HepG2细胞株,并给予不同浓度的前药GCV(ganciclovir)和/或5-FC(5-fluorocytosine),观察该体系对SCG7901细胞杀伤效应及其旁观者效应.结果:携带双自杀基因和报告基因(GFP)的重组腺病毒载体,感染复数为100时,95%以上的受感染SCG7901和HepG2细胞中有GFP表达.已转染腺病毒的SCG7901和未转染SCG7901的细胞在细胞生长方面无显著性差异(t=0.224,P=0.823).已转染腺病毒的HepG2细胞和未转染HepG2的细胞在细胞生长方面也无显著性差异(t=0.120,P=0.904).在前药应用下,已转染腺病毒的SCG7901和HepG2细胞表现出对前药不同的敏感性,SCG7901细胞对前药具有较高的敏感性(F=109.43,P=0.000).融合基因的疗效优于单一自杀基因(F=162.22,P=0.000).将感染腺病毒细胞与未感染细胞以不同比例混和培养,观察到该体系明显的旁观者效应.结论:KDR基因启动子可以调控融合基因体系选择性地杀伤人胃癌SCG7901细胞,并存在旁观者效应.

AIM： To study effect of adenovirus （Ad）- mediated fusion gene system driven by KDR promoter on the proliferation of human gastric adenocarcinoma cell line SGC7901. METHODS： SCG7901 cells （with KDR expression） and HepG2 cells （without KDR expression） were both transfected with AdEasy-KDR- CDglyTK vector, followed by treatment of the prodrugs 5-fluorocytosine （5-FC） and/or ganciclovir （GCV） at different concentrations. The killing and bystander effects on both kinds of cells were evaluated. RESULTS： The green fluorescent protein （GFP） was observed in 95% of the infected SCG7901 and HepG2 cells when the multiple of infection （MOI） was 100. No significant difference was found in the characteristics of growth between the transfected and non-transfected SCG7901 cells （t = 0.224, P = 0.823）. In the same time, there was also no significant difference between the transfected and non-transfected HepG2 cells （t = 0.120, P = 0.904）. The infected cells exhibited different sensitivities to the two kinds of prodrugs： SCG7901 cells infected with Ad were highly sensitive to the prodrugs （F = 109.43, P =0.000）, while the infected HepG2 cells were not. In addition, the killing effect of CDglyTK fusion gene on the target cells was notably stronger than that of either single suicide gene （F = 162.22, P = 0.000）, and a considerable bystander effect was also observed. CONCLUSION： CDglyTK fusion gene system driven by KDR promoter can selectively kill SCG7901 cells, and there exists an obvious bystander effect during this process.