腺病毒介导的HSV-tk/GCV自杀基因系统体内外旁观者效应的观察

In vitro and in vivo bystander effect of adenovirus-mediated transfer of the herpes simplex virus thymidine kinase gene

目的 观察腺病毒介导的HSV tk/GCV自杀基因系统的体外、体内接触及体内远端旁观者效应。 方法 采用向体外培养的tk阴性人肝癌BEL 74 0 2细胞中加入不同比例tk阳性同种细胞 ;向荷tk阴性BEL 74 0 2瘤小鼠瘤体内注射不同数量tk阳性同种细胞 ;向双侧荷瘤小鼠一侧瘤体内注射重组腺病毒 ,GCV作用后用不同方法来观察不同情况下的旁观者效应。 结果 体外组中观察到明显旁观者效应 ,当tk阳性细胞占 10 %时 ,混合细胞存活率为 36 6 % ;体内接触组中也观察到旁观者效应 ,实验组瘤体生长明显受到抑制 (P <0 0 5 ) ;体内远端组中 ,未观察到旁观者效应 (P >0 0 5 )。结论 腺病毒介导的HSV

Objective To investigate in vitro and in vivo bystander effect, including distance bystander effect of adenovirus mediated transfer of the herpes simplex virus thymidine kinase gene (HSV tk). Methods In vitro, mixed tk+BEL 7402 cells and tk BEL 7402 cells in diverse proportions and ganciclovir (GCV) was given, then tested the survival ratio of cells by MTT. In vivo, 5×10 6 and 5×10 7 tk+BEL 7402 cells were injected into the tumors in nude mice following GCV. The change of the size of the tumors was observed. To observe distance bystander effect, adenovirues with HSV tk(1×10 9 PFU) were injected into the tumor, which was the one of the bilateral tumors in nude mice. Subsequenthly, GCV was given and the change of the tumor was observed. Results Significant bystander effect was observed in vitro and in vivo. In vitro when tk+cells: tk - cells was 1∶9, the survival rate of mixed cells was 36 6% . When the propotion of tk +cells was 90%, the survival rate of mixed cells was 3 2%. In vivo, those tumors with injection of tk +BEL 7402 cells were suppressed ( P <0 05). But in group of distance bystander effect the tumors on another side were not suppressed. Conclusion In vitro, bystander effect exists. In nude mice, if tk +cells and tk -cells are contiguous, bystander effect is significant, or probably no bystander effect.