Let-7a下调k-Ras和c-Myc癌基因的表达抑制肾癌细胞增殖  

Let-7a Inhibits the Proliferation in Renal Cell Carcinoma Cell Lines by Regulating k-Ras and c-Myc Gene Expression

作　　者：吴银霞 王业华 齐小康 顾沈阳 俞俊杰 

机构地区：[1]扬州大学临床医学院肿瘤科,江苏扬州225001 [2]扬州大学临床医学院泌尿外科,江苏扬州225001

出　　处：《现代生物医学进展》2014年第6期1036-1039,共4页Progress in Modern Biomedicine

摘　　要：目的:MicroRNA是近年发现的一类单链小分子RNA,对它的研究已成为一个新的热点。最近的研究发现,1et-7a在细胞内影响着基因的表达调控,在疾病发生中起着及极重要的作用,尤其是在肿瘤的发展过程中,let-7a扮演着不可替代的角色。本文主要研究let-7a在肾癌细胞株中的表达情况及其调控的靶基因、抑制细胞增殖的机制,对探索肾癌的致病基因,寻求肾癌新的治疗途径有重要意义。方法:应用化学合成的let-7a模拟物(mimics)用脂质体Lipofectamine 2000在体外瞬时转染786-O和Caki-1肾癌细胞株,转染48小时后采用荧光定量RT-PCR的方法检测let-7a及c-Myc、k-Ras mRNA的表达情况,Western blot检测这两株肾癌细胞转染了let-7a mimics后c-Myc及k-Ras蛋白的表达变化;转染let-7a mimics后分别在24、48、72小时三个时间点用CCK-8试剂盒检测对肾癌细胞株增殖的影响。结果:786-O和Caki-1肾癌细胞株中let-7a的表达量明显低于正常肾小管上皮细胞株HK-2(P<0.05);转染了let-7amimics的786-O和Caki-1肾癌细胞株,RT-PCR及Western blot结果显示c-Myc、k-Ras在基因及蛋白的表达水平明显下调(P<0.05);CCK-8检测结果显示转染了let-7a mimics的肾癌细胞株细胞增殖能力明显明显受到抑制,与阴性对照组比较差异有统计学意义(P<0.05)。结论:Let-7a在在肿瘤细胞与正常细胞中存在明显差异,let-7a通过调控c-Myc、k-Ras的表达能抑制肾癌细胞增殖。Let-7a mimics可以抑制肾癌细胞的增殖,因此上调Let-7a的表达有可能成为肾癌基因治疗的一种有效治疗手段。Objective： MicroRNA is a type of the single small RNA discovered in recent years, and the study of it has become a new hot spot. Let-7a plays a very important role and affects the expression of genes in cells. Especially let-7a plays an irreplaceable role in the process of tumor development.This article mainly researches the expression of let-7a in kidney cancer cell lines and regulation of target genes and the mechanism of inhibition of cell proliferation. It is a great significance to explore the pathogenic genes and new treat- ment approaches in kidney cancer. Methods： Application of chemical synthesis of the let-7a mimics with Lipofectamine 2000 transient transfects in 786-0 and Caki-1 kidney cancer cell lines was taken. The let-7a and c-Myc, k-Ras mRNA expressions were detected with method of RT-PCR after transfection. The expression changeswere tested with Western blot. Effects of let-7a in cell proliferation were eval- uated by CCK-8 assay. Results： Transfection of the let-7amimics in Cak-i and 786-Orenal cancer cell lines, that the c-Myc, k-Ras gene and protein expression level significantly reduced（P〈0.05）. The expression levels of let-7a in 786-0 and Caki-1 ells were lower than nor- mal renal tubular epithelial cell lines HK-2 （P〈0.05）. Over-expression of let-7a in 786-O and Caki- 1 cells suppressed c-Myc, k-Ras gene and protein level. The result showed by RT-PCR and Western blot （P〈0.05）. CCK-8 test results showed that transfection let-7a mimics inhibit their proliferation ability was significantly suppressed compared with negative control group（P〈0.05）. Conclusion： These findings suggest that Let-7a plays an important role in kidney cancer cell lines proliferation through suppressing c-Myc, k-Ras in vitro, which pro- vides a potential development of a new approach for the treatment of renal cancer.

关 键 词：Let-7a KRAS c—myc 肾细胞癌 细胞增殖 

分 类 号：R737.11[医药卫生—肿瘤]