Let-7a对人乳腺癌MCF-7细胞的作用及机制探讨  

Effects and mechanism of Let-7a on the human breast cancer MCF-7 cells

作　　者：吴凯[1] 吴爱国 马雷[1] 杨华峰[1] 孟艳辉[1] 

机构地区：[1]南方医科大学珠江医院,广州510282

出　　处：《山东医药》2010年第15期29-31,共3页Shandong Medical Journal

基　　金：广东省科技计划基金资助项目(2008B030301345)

摘　　要：目的观察Let-7a对体外生长的人乳腺癌MCF-7细胞株的抑制作用,并探讨其作用机制。方法分别用LipofectamineTM2000介导的Let-7a和siRNA转染人乳腺癌细胞株MCF-7(分别为Let-7a组、空白对照组和阴性对照组),半定量RT-PCR法检测两组C-myc mRNA表达;Western blot法测定转染24 h后C-myc蛋白的表达水平;CCK-8法检测细胞增殖抑制率。结果Let-7a组的C-myc mRNA表达水平明显低于空白对照组和阴性对照组,P均<0.01;在MCF-7细胞中存在相对分子质量62 kD的特异性条带,与C-myc相对分子质量相符,Let-7a组特异性条带明显弱于对照组;Let-7a组细胞增殖抑制率明显高于阴性对照组(P<0.05),且具有时间和浓度依赖性。转染24 h后,Let-7a组凋亡率明显高于对照组(P<0.05)。结论Let-7a对体外生长的人乳腺癌MCF-7细胞增殖有抑制作用;其机制可能为抑制C-myc基因的表达。Objective To investigate the inhibitory effect of Let -7a on the human breast cancer MCF-7 eels in vitro and explore its possible mechanism. Methods Human breast cancer MCF-7 cells were transfected with Let-7a and siRNA mediated by Lipofectamine^TM 2000 （ which were Let -7a group ,blank control group and negative control group respectively）. The mRNA expression of C-myc of each group was detected using semi-quantitive reverse transcription-polymerase chain reaction（RT-PCR） ; The level of C-myc protein expression was measured by western blot 24 hours after transfection; The cell proliferation inhibitory rate was measured using CCK-8 assay. Results The expression of C-myc mRNA in let-7a group was significantly lower than that in the blank control group and negative control group （ both P 〈 0.01 ） ; Specific band with the relative molecular mass of 62 kD was found in the MCF-7 cells,which was coincided with the molecular mass of C-myc,the specific band in Let -7a group was obviously weaken than those in control groups; The cell proliferation inhibitory rate in Let-7a group was obviously than that in negative control group（P 〈0.05） , and which showed dose and time-dependent manner. Apeptotic index in Let-7a group was obviously higher than that in the control groups （ P 〈 0.05 ） 24 hours after transfection. Conclusion Let-7a can inhibit the proliferation of MCF-7 cells in vitro by reducing the C-myc gene expression .

关 键 词：C-MYC基因 Let-7a 乳腺癌 微小RNA 细胞转染 

分 类 号：R737.9[医药卫生—肿瘤]