microRNA194过表达抑制荷瘤小鼠肝癌细胞生长的实验研究*

目的 探讨microRNA194过表达对肝癌细胞生长的抑制作用及其具体作用机制。方法 通过细胞转染法构建过表达microRNA194的肝癌细胞Hep3B,并将其接种于Balb/c裸鼠建立荷瘤小鼠。30只Balb/c裸鼠被随机分配为microRNA194过表达组15只和对照组15只,采用荧光定量PCR法检测Hep3B细胞和荷瘤小鼠肝癌组织microRNA194水平,采用荧光定量PCR法和Western blot法分别检测肿瘤组织胰岛素样生长因子1受体（IGF1R）水平及其蛋白表达情况。结果 Hep3B细胞和荷瘤小鼠肝癌组织microRNA194 mRNA水平分别为（2.68±0.33）和（2.33±0.38）,均显著高于对照组【分别为（1.00±0.12）和（1.00±0.16）,P<0.01】;在肝癌细胞接种第11 d、16 d和21 d时,microRNA194过表达组小鼠肝肿瘤体积分别为（0.25±0.08）、（0.31±0.11）和（0.46±0.10）mm³,均显著小于对照组【分别为（0.56±0.13）、（0.73±0.20）和（0.95±0.22）mm³,P<0.01】;在肝癌细胞接种第21 d时,microRNA194过表达组小鼠肝肿瘤质量为（0.85±0.19）g,显著轻于对照组【（1.43±0.27）g,P<0.01】;microRNA194过表达组小鼠肝肿瘤IGF1R mRNA水平和其蛋白表达量分别为（0.78±0.12）和（0.81±0.17）,均显著低于对照组【分别为（1.0±0.16）和（1.0±0.11）,P<0.01】。结论 microRNA194过表达可以抑制肝癌细胞生长,有可能是通过抑制了下游靶基因IGF1R的表达而发挥作用的。

Inhibition of hepatocellular carcinoma growth by microRNA194 overexpression in Balb/c nude mice

Objective To explore the inhibitory effect on hepatocellular carcinoma growth by microRNA194 overexpression in Balb/c nude mice,and the possible mechanism by which the microRNA194 works. Methods We constructed the hepatoma cell Hep3B with microRNA194 overexpression by cell transfection and the cells were subcutaneously inoculated into Balb/c nude mice. Then,the microRNA194 overexpression was verified in Hep3B cells and in the tumor tissues by real-time fluorescent quantitative PCR. Thirty Balb/c nude mice were randomly assigned to the microRNA194 overexpression group （n=15） and the control group （n=15）. The tumor volume was measured every 5 days and the tumor weight was measured at 21 days post-inoculation. Finally,real-time fluorescent quantitative PCR and Western bolt were performed to detect insulin-like growth factor 1 receptor （IGF1R） mRNA levels and its protein expression respectively. Results The microRNA194 levels in Hep3B cells and in tumor tissues with microRNA194 overexpression were （2.68±0.33） and （2.33±0.38）,much higher than in the control group【（1.00±0.12） and（1.00±0.16）,respectively,P<0.01】;At day 11,day 16 and day 21 post-inoculation,the tumor volume in the microRNA194 overexpression group were （0.25±0.08）,（0.31±0.11） and （0.46±0.10） mm³,much lower than in the control group 【（0.56±0.13）,（0.73±0.20） and （0.95±0.22） mm³,P<0.01】;At day 21 post-inoculation,the tumor weight in the microRNA194 overexpression group was （0.85±0.19） g,much lower than in the control group【（1.43±0.27） g,P<0.01】;the mRNA level and its protein expression of IGF1R in the microRNA194 overexpression group were（0.78±0.12） and （0.81±0.17）, much lower than in the control group 【（1.0±0.16） and （1.0±0.11）,P<0.01】. Conclusion The overexpression of microRNA194 might inhibit tumor growth by suppressing the expression of IGF1R, which needs further investigation.