单纯疱疹病毒胸苷激酶基因和更昔洛韦对膀胱癌细胞的旁观杀伤效应

HSV-TK/GCV system-mediated bystander tumoricidal effect on bladder cancer cells

目的 探讨单纯疱疹病毒胸苷激酶 (HSV tk)基因和更昔洛韦 (GCV)对膀胱癌细胞的旁观者效应和机制。方法 将转染HSV tk基因的膀胱癌细胞HTB9与HTB9细胞混合培养 ,在GCV作用下 ,观测细胞的存活率。HTB9 tk细胞条件培养基 ,经不同孔径的滤膜过滤 ,将滤液及0 .2 2 μm滤膜上的物质重新加入HTB9细胞 ,观察细胞存活率。结果 当HTB9 tk细胞 50 %时 ,共培养细胞对GCV的敏感性近 1 0 0 %,表明每个表达HSV tk基因的细胞至少杀死 1个不含HSV tk基因的膀胱癌细胞。HTB9 tk细胞的条件培养液过滤后直径大于 0 .2 2 μm的某种物质对HTB9细胞具有细胞毒性作用。结论 HSV tk/GCV对膀胱癌细胞具有明显旁观者效应的毒性作用 ,直径大于 0 .2 2 μm的某种物质对HTB9细胞具有细胞毒性作用 ,其旁观杀伤效应机理可能是HTB9对HTB9

Objective To investigate the hystander tumoricidal effect mediated by HSV TK/GCV system on bladder cancer cells and the possible mechanisms of bystander effects.Methods HSV Tk gene transduced HTB9 cells were cocultured with the human bladder cancer cells(HTB9,ScaBER).In the presence of ganciclovir,the cell survival rate was monitored.Results When the proportion of HTB9 TK cells was about 50%,the cocultures that contained 50% HTB9 TK cells were as sensitive to GCV as cultures containing 100% HTB9 TK cells.This indicated that one cell expressing HSV TK gene was capable of mediating death to at least one tumor cell carrying no HSV TK gene.The conditioned media from cultures of HTB9 TK cells in the presence of GCV exhibited no effects on survival of the HTB9 parental cells.Conclusion The bystander effect among the bladder carcinoma lines in this study,which was not mediated by the cytotoxic effects of cell lysis or by a solubal factor by culturing HSV TK,was specific for cytotoxicity induced by HSV TK/GCV system.