IL-18基因转染对小鼠卵巢癌OVHM体外增殖及体内成瘤的影响

目的:分析转染IL-18基因后,对小鼠卵巢癌OVHM细胞体外增殖、凋亡及体内成瘤的影响,初步探讨IL-18基因转染治疗卵巢癌的应用价值.方法:将逆转录病毒携带的小鼠IL-18基因成功转染至OVHM(OVHM/IL-18),以空载体转染的OVHM(OVHM/LXSN)和野生型(OVHM)作为对照.分别采用MTT、FCM检测体外培养细胞的增殖、凋亡及周期分布.于裸鼠皮下分别接种细胞,观察各组种植瘤生长情况,计算成瘤率;RT-PCR检测瘤组织中IL-18 mRNA表达;FCM和电镜分析肿瘤细胞增殖、凋亡状况.结果:3组细胞的体外增殖未见明显差异,均无明显凋亡现象,增殖指数、细胞周期分布均无明显差异(均P>0.05).接种后,3组裸鼠的成瘤率相同,但OVHM/IL-18组成瘤时间较晚,随瘤龄增长肿瘤生长缓慢,瘤组织中IL-18 mRNA阳性表达.OVHM/IL-18组裸鼠种植瘤细胞可见典型的凋亡现象,G0/G1期细胞明显增多,S期细胞明显减少,增殖指数明显降低,凋亡指数明显增高(P<0.01).结论:IL-18基因成功转染后,虽对体外卵巢癌细胞无直接毒性,但可能在体内借助非直接杀伤的其他途径,通过阻断细胞周期、促进肿瘤细胞凋亡等抑制体内成瘤.

Effects of IL-18 gene transfection on the proliferation in vitro and tumorigenesis in vivo of mouse ovarian cancer cell line OVHM

AIM: To investigate the effects of IL-18 gene transfection on proliferation, apoptosis and tumorigenesis of mouse ovarian cancer cell line OVHM. METHODS: OVHM were transfected with retrovirus encoding IL-18 gene (OVHM/IL-18). The wild OVHM and OVHM transfected with vector without IL-18 gene (OVHM/LXSN) were enrolled as the controls. The proliferation, cell cycle and apoptosis were measured by MTT and FCM respectively. The nude mice were subcutaneously inoculated with the three different cells respectively. The observation of transplanted tumor's growth and calculation of tumorigenesis ratio was made. The expression of IL-18 mRNA in tumor tissues was detected by RT-PCR, and the apoptosis of tumor cell in tissue was analyzed by electron microscope and FCM. RESULTS: The three cells cultured in vitro showed no apoptotic peaks, and no differences in proliferation and cell cycle (All P>0.05). Following inoculation, the ratios of tumorigenesis were similar in all the three groups. But in OVHM/IL-18 group, the latent period of tumorigenesis was longer with slower tumor growth rate and positive expression of IL-18 mRNA in tumor tissue. It was also observed that in the tumor cells from nude mice inoculated by OVHM/IL-18, the cells in phase of G0/G1 increased with typical morphology of apoptosis, and those in S phase decreased with decreased proliferation index and increased apoptosis index (All P<0h01). CONCLUSION: Although IL-18 gene has no cytotoxic effects in vitro, its inhibiting effects on tumorigenesis of OVHM in vivo were exerted by interdicting cell cycle and accelerating apoptosis of tumor cells.