miR-21介导的结肠癌细胞对5-氟尿嘧啶的耐药机制研究  

Drug resistance of colon cancer cells to 5-fluorouracil mediated by microRNA-21

作　　者：吴丽媛[1] 李偲[1] 彭锐[1] 龚舒[1] 徐柳[2] 邹方东[1] 

机构地区：[1]四川大学生命科学学院,成都610064 [2]西南交通大学生命科学与工程学院

出　　处：《中华医学遗传学杂志》2015年第5期620-624,共5页Chinese Journal of Medical Genetics

基　　金：中央高校基本科研业务费专项资金（SWJTU11CX116）;四川省青年科技创新研究团队资助（2011JTD0026）

摘　　要：目的通过检测microRNA-21（miR-21）及其靶基因程序性细胞死亡因子4（programmedcelldeath4，PDCj）4）基因在结肠癌细胞中对下游通路的调控，研究高表达的miR-21在结肠癌细胞中对5-氟尿嘧啶（5-fuorouracil，5-FU）耐药的可能机制。方法MTT法检测5-FU处理后miR-21敲除或PDCD4高表达对RKO细胞存活率的影响；流式细胞术检测5-FU处理后RKO-敲除型与RKO-野生型细胞凋亡；定量PCR检测miR-21敲除后以及PDCD4高表达后RKO细胞中ABCC5及CD44mRNA水平的变化。结果5-FU对RKO-野生型的半抑制浓度（IC50）值（52．28±0．05）μmol／L比RKO-敲除型的ICso值（32．13±0．05）μmol／L高67％，同时miR-21敲除后细胞凋亡率显著增加；PDCD4在RKO-敲除型细胞中显著高表达，并且高表达的PDCD4能够负调控转运蛋白ABCC5及干细胞表面标记CD44。结论miR-21很可能通过抑制靶基因PDCD4调控转运蛋白ABCC5及干细胞表面标记CD44的表达，从而增强RKO细胞对5-FU的耐药性。Objective To explore downstream regulatory pathway of microRNA-21 （miR-21） in colon cancer cells （RKO） through detecting miR-21 and its target PDCD4, and the influence of miR-21 regulation on the sensitivity of RKO cells to 5-fluorouracil （5-FU）. Methods 3-[-4, 5-dimethylthiazol-2-yl]-2, 5- diphenyltetrazolium bromide （MTT） assay was used to determine the effect of 5-FU on the viability of RKO cells with knockout of miR-21 or high expression of PDCD4. Real-time was used to determine the expression of PDCD4, ABCC5 and CD44 in RKO cell after knockout of miR-21. Results MTT assay reveals that the ICs0 of 5-FU in RKO-WT cells [（52.82±0.06） μmol/L] was^67% higher than in miR-21 knockout cells F（32. 23±0. 05） μmol/L] （P〈0.05）, and the apoptosis ratio elevated after knockout of miR-21. High expression of PDCD4, a target gene of miR-21, can negatively regulate the expression of ABC transporter ABCC5 and the stem cell marker CD44. Conclusion MiR-21 can mediate the drug resistance to 5-FU by inhibiting its target PDCD4, which can regulate the expression of ABCC5 and CD44 genes.

关 键 词：MICRORNA-21 结肠癌细胞 5-氟尿嘧啶 程序性细胞死亡因子4基因 

分 类 号：R730.264[医药卫生—肿瘤]