逆转录病毒载体介导HSV-tk基因经尿道膀胱灌注对大鼠膀胱癌的杀伤作用

Killing effect of the retrovirus vector containing HSV-tk gene on MNU-induced rat bladder tumor by intravesical instillation

目的 探讨经尿道膀胱灌注由逆转录病毒介导的HSV tk基因对大鼠膀胱肿瘤的治疗作用。方法 N 甲基亚硝基脲(MNU)膀胱灌注诱导雌性Wistar大鼠膀胱肿瘤。经尿道HSV tk基因膀胱灌注后 ,RT PCR检测肿瘤组织中tk基因表达 ;TUNEL法检测肿瘤细胞凋亡 ;荷瘤膀胱总重量检测。结果 HSV tk基因经尿道膀胱灌注后 ,RT PCR检测膀胱肿瘤组织有tk基因mRNA表达 ;TUNEL法凋亡检测 ,荷瘤膀胱总重量测定 ,提示治疗组与对照组有显著差异。结论 经尿道膀胱灌注逆转录病毒载体 /HSV tk可转导tk基因 ;联合GCV治疗 ,肿瘤生长被显著抑制 ;诱导肿瘤细胞凋亡可能是其作用机理之一。

Objective To investigate the retrovirus-mediated gene killing effect on murine bladder cancer in vivo by simple instillation.Methods The orthotopic rat bladder cancer was established in female Wistar rats by intravesical administration of the carcinogen, N-methyl-nitrosourea (MNU). A retrovirus vector containing HSV-tk gene was transurethrally instilled into the bladder. GCV was injected intraperitoneally the next day after instillation for 6d.The distribution of the gene was examined by reverse transcriptase -polymerase chain reaction (RT-PCR). Tumor incidence and tumor weight, defined as the weight of the tumored bladder, were determined on day 6 and 10 after GCV intraperitoneal injection for 6d.Apoptosis of tumor cells were detected with in situ DNA nick end labeling (TUNEL).Results The suicide gene transferred into the tumor cells and expressed successfully by instillation of retrovirus vector containing HSV-tk was conformed by RT-PCR. Significant difference was observed between the weight of the tumored bladder or the quantity of the apoptosis tumor cells treated by HSV-tk/GCV system rats and the control rats.Conclusions Our study shows that transurethral instillation of retrovirus vector could transfer the HSV-tk gene to the rat bladder tumor cells effectively. HSV-tk/GCV system can acts as a candidate treatment for bladder cancer therapy. Inducing apoptosis of tumor cells might be the important mechanism of HSV-tk/ GCV system.