HSV-tk/GCV系统对人宫颈癌细胞株ME180旁观者效应的研究

目的：研究以逆转录病毒载体介导的HSV－tk/GCV系统对宫颈癌ME180细胞株的旁观者效应。方法：应用脂质体及ploybrene转染技术，将重组逆转录病毒载体PLXSN－HSV－tk，导入PA317包装细胞，以其分泌的逆转录病毒感染宫颈癌ME180细胞（ME），建立ME／TK转化细胞株。观察GCV对ME、ME／TK细胞的存活率及旁观者效应。结果：从病毒滴度、电镜及PCR检查，证实tk基因随病毒的感染已成功地导入PA317及ME180细胞。ME／TK细胞对GCV的敏感性显著高于亲代ME细胞。ME／TK及ME＋ME／TK混合细胞还随GCV浓度的增加受到明显的抑制。ME＋ME／TK混合细胞的存活率，随ME／TK细胞比例的增加而降低，说明TK／GCV系统不但能杀伤tk^ 细胞，也能杀伤未导入tk的细胞，存在明显的旁观者效应。结论：HSV－tk/GCV系统对宫颈癌ME180细胞具有明显的杀伤及旁观者效应。

The Bystander Effect of HSV-tk/GCV System on Human Cervical Carcinoma Cell Line ME180

Objective To investigate the bystander effect of HSV tk/GCV system retroviral vector mediated on human cervical carcinoma cell line ME180(ME). Methods By the use of lipofectin and polybrene transfection techniques, recombinant retroviral vector plxsn HSV tk was tansduced into packing cell line PA317 and the obtained recombinant retrovirus was applied to infect ME cells and establish transfection cell line. The effect of GCV on survival rate and bystander effect of ME and ME/TK cells was observed by cell culture and MTT test. Results Transduction of TK gene into PA317 and ME cell lines was successful and validated by viral titer, electron microscope and PCR detection.The ME/TK cells showed significantly higher sensitivity to GCV than parental ME cells. ME/Tk and ME+ME/TK mixed cells were obviously suppressed with the gradational increase of GCV concentration.And the survival rate of ME+ME/TK mixed cells decreased with the increase of ME/TK ratio in mixed cells. It implied that TK/GCV system could kill not only tk + cells but also untransduced tk cells in mixed cells, thus verifying the presence of bystander effect. Conclusion The above results demonstrate that HSV tK/GCV system has obvious killing and bystander effect on cervical carcinoma cell line ME 180.