Gene therapy using apoptosis-inducer bax and suicide gene for chemically induced rat bladder cancer

研究了单纯疱疹病毒1型胸苷激酶（HSVtk）基因联合更昔洛韦（GCV）体内电转基因治疗大鼠膀胱癌的有效性。体外研究表明，50-70%的移行细胞癌（TCC）细胞由于用pHSVtk转染和GCV施用而死亡，并且这种处理与DNA合成减少和半胱天冬酶-3、-8和-9的活性升高有关。在给予pHSVtk+GCV的TCC细胞中还观察到线粒体膜电位显着降低。使用体内电基因转移将HSVtk直接单次注射到膀胱肿瘤中，随后给予GCV，导致细胞凋亡和组织病理学坏死水平显著增加，伴有明显的炎症。pHSVtk/GCV治疗组大鼠膀胱移行细胞癌细胞死亡区有活性caspase-3的强表达。体内电基因转移导致化学诱导的大鼠膀胱肿瘤中有效的基因转移，并且HSVtk/GCV产生系统诱导明显的细胞死亡，这似乎至少是通过线粒体凋亡途径介导的。

The effectiveness of in vivo electrogene transfer as a means of gene therapy for rat bladder cancers using the herpes simplex virus 1 thymidine kinase (HSVtk) gene in combination with ganciclovir (GCV) was investigated. In vitro studies demonstrated that 50-70% of the transitional cell carcinoma (TCC) cells died as a result of transfection with pHSVtk and GCV administration and that this treatment was associated with decreased DNA synthesis and elevated activities of caspase-3, -8 and -9. A significantly decreased mitochondrial membrane potential was also noted in TCC cells given pHSVtk+GCV. A direct single injection of HSVtk into bladder tumors using in vivo electrogene transfer followed by GCV administration resulted in significant increases in the levels of apoptosis and histopathological necrosis accompanied by marked inflammation. Active caspase-3 was strongly expressed in the cell death areas of the TCC in rats given pHSVtk/GCV therapy. In vivo electrogene transfer results in efficient gene transfer in chemically induced rat bladder tumors and the HSVtk/GCV producing system induces significant cell death which appears to be, at least, mediated via the mitochondrial apoptotic pathway.