研究多聚乙烯基亚胺(PEI)介导的卵巢特异性启动子调控下的自杀基因对卵巢癌的抗肿瘤作用。 方法: （1）将卵巢特异性启动子调控下的真核表达质粒pOSP1-HSVtk利用PEI导入人卵巢癌细胞SKOV3，人肺癌细胞NCI-H460和人肝癌细胞HepG2，MTT法测定GCV对三种肿瘤细胞的杀伤作用；(2)建立卵巢癌移植瘤模型，瘤周注射PEI/pOSP1-HSVtk复合物，通过HPLC监测体内GCV浓度的变化来评价TK基因在肿瘤组织中的表达效率；同时记录裸鼠的体重、瘤体大小及瘤重，计算体积和重量抑瘤率，并进行肿瘤组织的病理学和TUNEL检测。 结果: （1）GCV仅对SKOV3细胞具有杀伤作用；(2)与对照组相比，GCV的浓度在转染pOSP1-HSVtk的肿瘤组织局部显著降低(0.05>P>0.01)；治疗组的肿瘤体积和瘤重显著减小(P<0.01)，体积抑瘤率与重量抑瘤率分别为63.66%和58.98%。组织学示治疗组肿瘤细胞有出血及坏死，TUNEL证实了细胞的凋亡。 结论： 多聚乙烯基亚胺介导的卵巢特异性启动子调控下的自杀基因对卵巢癌有靶向杀伤作用。

Objective: To study the anti-tumor effects of suicide gene therapy using an ovarian-specific promoter and polyethylenimine(PEI) mediated transfection. Methods : (1) The pOSP1-HSVtk plasmids containing an ovarian-specific promoter were transfected using PEI into the Human ovarian carcinoma cell SKOV3, Human lung carcinoma cell NCI-H460 and Human heptocellular carcinoma cell HepG2. The cytotoxicities resulted from GCV were evaluated using the MTT assay. (2) Ovarian cancer xenograft model was established and the PEI/ pOSP1-HSVtk complex were injected around the xenograft. The expressed TK activities were estimated by monitoring the GCV concentration change using a HPLC assay. The weight of the nude mice, the tumor volumes and tumor weights were all recorded to calculate the tumor inhibition rates by weight and by volume. Histopathological analysis and TUNEL method were also performed. Results : (1) GCV was shown to be toxicity only in SKOV3 cells. (2) Compared with the control group, GCV concentrations in tumor tissues transfected pOSP1-HSVtk were shown to be significantly lower (0.05>P>0.01). The tumor volume and the tumor weight were also significantly decreased in the treated group(P<0.01). The tumor volume inhibition rate and the tumor weight inhibition rate were estimated to be 63.66% and 58.98% respectively. Histological examination revealed heavy haemorrhage and necrosis in the tumor tissues, and TUNEL confirmed substantial cell apoptosis in the treated group. Conclusion: The suicide gene therapy system using an ovarian-specific promoter by polyethylenimine mediated transfection has a targeting killing activity on human ovarian cancer.