婴儿双歧杆菌介导HSV-TK/GCV对前列腺癌PC-3细胞裸鼠移植瘤细胞凋亡的影响

Effects of HSV-TK/GCV suicide gene therapy system mediated by bifidobacterium infantis on cell apoptosis of prostate cancer PC-3 cell xenografts in nude mice

目的:研究婴儿双歧杆菌(bifidobacterium infantis,BI)介导单纯疱疹病毒胸苷激酶(herpes simplex virus thymidine kinase,HSV-TK)/丙氧鸟苷(ganciclovir,GCV)自杀基因系统对PC-3细胞裸鼠移植瘤细胞凋亡的影响。方法:采用前列腺癌PC-3细胞悬液皮下注射法建立裸鼠前列腺癌模型,并随机分为4组,每组各12例,分别经尾静脉注射BI-p GEX-TK(重组质粒组)、BI-p GEX-5X-1(空质粒组)、BI(空婴儿双歧杆菌组)和生理盐水(生理盐水组),联合腹腔注射GCV,4周后,称取裸鼠质量及肿瘤质量。TUNEL法检测各组肿瘤细胞凋亡情况,real-time PCR、Western blot分别检测各组肿瘤组织中Fas、FAP-1、casepase3和casepase8的m RNA及蛋白表达水平。结果:重组质粒组荷瘤裸鼠体质量明显高于其余3组(F=12.952,P=0.000),肿瘤组织质量明显降低(F=7.795,P=0.000);重组质粒组凋亡指数明显高于其他3组(F=45.895,P=0.000);重组质粒组Fas m RNA(F=70.077,P=0.000)、casepase3 m RNA(F=70.611,P=0.000)和casepase8 m RNA(F=73.781,P=0.000)的表达明显上调,FAP-1 m RNA(F=46.880,P=0.000)的表达明显下调。重组质粒组Fas蛋白(F=664.116,P=0.000)、casepase3蛋白(F=203.090,P=0.000)和casepase8蛋白(F=654.354,P=0.000)的表达明显上调,FAP-1蛋白(F=318.989,P=0.000)的表达明显下调。结论:婴儿双歧杆菌介导HSVTK/GCV自杀基因系统可能通过影响Fas介导凋亡信号通路,诱导荷瘤裸鼠前列腺癌细胞的凋亡,发挥抑癌作用。

Objective：To investigate the effect of bifidobacterium infantis（BI）-mediated herpes simplex virus thymidine kinase（HSVTK）/ganciclovir（GCV）suicide gene therapy system on cell apoptosis of prostate cancer PC-3 cell xenografts in nude mice. Methods：The prostate cancer model was established by subcutaneous injection of human prostate cancer cell line PC-3 into nude mice.The model mice were randomly divided into 4 groups,which were treated by intraperitoneal injection of GCV in combination with tail vein injection of BI carrying recombinant plasmid BI-p GEX-TK（recombinant plasmid group）,BI carrying empty plasmid BI-p GEX-5x-1（empty plasmid group）,BI（BI group）and normal saline（normal saline group）. After 4 weeks of treatment,tumor weights and nude mice weights were recorded. The apoptosis of tumor was detected by TUNEL assay. The expression of Fas,FAP-1,casepase3 and casepase8 were determined by real-time q PCR and Western blot,respectively. Results：After treatment,comparing with those of empty plasmid group,BI group and normal saline group,the nude mice weights in recombinant plasmid group increased（F =12.952,P =0.000）,the tumor weights decreased（F=7.795,P=0.000）. The apoptosis index of recombinant plasmid group was obviously higher than that of the other three groups（F=45.895,P=0.000）. Comparing with the other three groups,the m RNA expression of Fas（F=70.077,P=0.000）,casepase3（F=70.611,P=0.000）and casepase8（F=73.781,P=0.000）in recombinant plasmid group increased,but the m RNA expression of FAP-1（F=46.880,P=0.000）decreased. Protein expression of Fas（F=664.116,P=0.000）,casepase3 F=203.090,P=0.000）and casepase8（F=654.354,P=0.000）in recombinant plasmid group increased,but the expression of FAP-1 protein（F =318.989,P =0.000）decreased. Conclusion：The BI-mediated HSV-TK/GCV suicide gene therapy system can inhibit nude mice prostate cancer progression effectively,probably through affecting Fas mediated apoptosis signaling pathways,inducing to nude mice prostate cancer cells apoptosis and playing a role in tumor suppression.