miR-124抑制人卵巢癌裸鼠皮下移植瘤的生长和转移

Inhibitory effect of miR-124 on the growth and metastasis of subcutaneous xenografts of human epithelial ovarian carcinoma in nude mice

目的:探讨微RNA-124(microRNA-124,miR-124)对人卵巢癌细胞株SKOV3裸鼠皮下移植瘤生长和远处转移的影响。方法:采用脂质体转染法将miR-124-模拟物(mimics)及其阴性对照(miR-124-mimics-negative control,miR-124-mimics-NC)分别瞬时转染至人卵巢癌SKOV3细胞中,随后将转染后的SKOV3细胞接种于裸鼠皮下,建立SKOV3细胞肿瘤模型。待成瘤后将miR-124-mimics或miR-124-mimics-NC联合脂质体每隔4 d进行一次瘤内定点注射治疗,至47 d后处死小鼠,绘制肿瘤生长曲线图并计算抑瘤率;采用实时荧光定量-PCR检测移植瘤组织中miR-124的表达情况;免疫组织化学法检测移植瘤组织中Ki-67及caspase-3的表达情况;观察肿瘤在小鼠中肝脏转移的情况,并对肝组织进行HE染色。结果:miR-124-mimics转染SKOV3细胞后,SKOV3细胞中miR-124的表达水平明显上调;47 d后处死小鼠,最终miR-124过表达组裸鼠皮下移植瘤的体积明显小于空白对照组和阴性对照组,差异有统计学意义(P<0.05),抑瘤效果明显;移植瘤中miR-124的表达上调,Ki-67表达明显下调,caspase-3表达明显升高;HE染色结果显示,空白对照组和阴性对照组裸鼠肝组织中都出现了肿瘤细胞浸润,而miR-124过表达组的裸鼠未出现肝转移。结论:miR-124对人上皮性卵巢癌裸鼠移植瘤生长和远端转移均具有抑制作用,有望成为卵巢癌基因治疗的新靶点。

Objective： To investigate the effect of microRNA-124 （miR-124） on growth and distant metastasis of subcutaneous xenografts of SKOV3 human epithelial ovarian cancer cell line in nude mice. Methods： SKOV3 cells were transiently transfected with miR-124-mimics or miR-124-mimics-negative control （miR-124-mimics-NC） by LipofectAMINE 2000 and then subcutaneously transplanted into nude mice to establish tumor models. After the xenografts formed in nude mice, miR-124-mimics or miR-124- mimics-NC combined with liposome was injected into xenografts every four days. The tumor growth and the change of tumor volume were observed. The nude mice were dissected at day 47 after the start of intratumoral injection. The tumor growth curve was drawn and the tumor inhibition rate was calculated. The expression level of miR-124 in tumor tissues was detected by real-time fluorogenic quantitative-PCR. The expressions of Ki-67 and caspase-3 proteins in tumor tissues were examined by immunohistochemistry. The nude mice were dissected to observe the liver metastasis and the liver tissues were stained with hematoxylin-eosin （HE）. Results： After transfection of miR-124-mimics into SKOV3 cells, the expression of miR-124 was significantly increased. The tumor volume of miR-124 group was significantly smaller than that of the blank control group and the negative control （NC） group 47 days after tumor formation with a statistical significance （P 〈 0.05）, the growth inhibitory effect on tumor in miR-124 group was obvious. As compared with the blank control group and the NC group, the expression level of miR-124 was elevated, the expression level of Ki-67 was significantly decreased, while the expression level of caspase-3 was significantly increased in miR-124 group tumor tissues. The result of HE staining showed tumor cell invasion in liver tissues in the blank control group and the NC group but not in miR-124 group. Conclusion： miR-124 can inhibit the growth and distant metastasis of subcutaneous xenografts of human epithelial ovarian cancer cells in nude mice, and it may be a potenital novel target of gene therapy for ovarian carcinoma.