经膀胱灌注阳离子脂质体介导的HVS-TK基因对大鼠膀胱癌的杀伤作用

Killing effect of cationic liposome-TK complexes on N-methyl-nitrosourea induced rat bladder cancer by intravesical instillation

目的 观察阳离子脂质体介导的 HSV- TK基因经尿道膀胱灌注对大鼠膀胱肿瘤体内杀伤作用。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 ;荷瘤膀胱总重量测定。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 m RNA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差异有显著性。结论 经尿道膀胱灌注阳离子脂质体 - TK复合物可转导 TK基因 ;联合 GCV治疗 ,肿瘤生长被抑制 ;诱导肿瘤细胞凋亡可能是 HSV- TK/ GCV系统作用机理之一。

Objective To investigate cationic liposome-TK complexes killing effect on murine bladder cancer in vivo by simple instillation.Methods The orthotopic rat bladder cancer model was established in female Wistar rats by intravesical administration of the carcinogen, N-methyl-nitrosourea(MNU). Cationic liposome-Tk complexes was transurethrally instilled into the bladder. GCV was injected intraperitoneally the next day after instillation for 6 days. 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 6 days. Apoptosis of tumor cells were detected with in situ DNA nick end labeling (TUNEL).Results The sucide gene transferred into the tumor cells and expressed successfully by instillation of cationic liposome-TK complexes 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 The study shows that transurethral instillation of cationic liposome-TK complexes can transfer the HSV-TK gene to the rat bladder tumor cells effectively. HSV-TK/GCV system can act as a candidate treatment for bladder cancer therapy. Inducing apoptosis of tumor cells might be the important mechanism of HSV-TK/GCV system.