miR-503下调Bcl-2增强BEL-7402/5-FU细胞对5-氟尿嘧啶的敏感性

miRNA-195 sensitizes BEL-7402/5-FU cells to 5-fluorouracil via down-regulating Bcl-2 expression

目的:探讨miR-503通过调控Bcl-2的表达介导肝癌耐药细胞株BEL-7402/5-FU对5-氟尿嘧啶敏感性的影响.方法:microRNA(miRNA)芯片筛选BEL-7402与BEL-7402/5-FU细胞中表达差异的miR-503为候选的miRNA;脂质体转染法将miR-503模拟物瞬时转染至BEL-7402/5-FU细胞;实时定量聚合酶链式反应(qRT-PCR)检测BEL-7402/5-FU及其亲本细胞中miR-503、Bcl-2 mRNA的表达水平;Western Blot观察肝癌细胞中Bcl-2蛋白的表达水平;CCK-8法检测细胞药物敏感性的改变.结果:相比于BEL-7402细胞,miR-503在BEL-7402/5-FU细胞中表达水平下调,而Bcl-2蛋白的表达水平上调;miR-503过表达后BEL-7402/5-FU细胞中的Bcl-2在mRNA和蛋白水平上表达降低;miR-503转染组的BEL-7402/5-FU细胞活力较miRNA阴性对照组显著降低.结论:miR-503可能通过下调Bcl-2的表达,进而增强BEL-7402/5-FU细胞对5-氟尿嘧啶的药物敏感性,抑制细胞增殖.

Aim：This study is to investigate the effects of miR-503 on 5-fluorouracil sensitivity of liver cancer drug resistant cell lines BEL-7402/5-FU by down-regulating Bcl-2 expression. Methods： Differentially expressed miR-503 between BEL-402 and BEL-7402/5-FU cells was screened by microRNA（ miRNA）,and was to be a candidate miRNA. MiR-503 mimic matter was transient transfected to the BEL-7402/5-FU cells by liposome transfection method. MiR-503 and Bcl-2 mRNA expression level of BEL-7402/5-FU and its parental cells were measured by qRT-PCR. Bcl-2 protein level was detected by western blot. Cell viability of each group was measured by CCK-8 assay. Results： MiR-503 level was downregulated and Bcl-2 protein expression level was up-regulated in BEL-7402/5-FU cells compared with BEL-7402 cells. MiR-503 could significantly down-regulate Bcl-2 expression in BEL-7402/5-FU cells.BEL-7402/5-FU cell vitality of miR-503 transfection was significantly reduced compared with negative control. Conclusion：miR-503 could enhance sensitivity of BEL-7402/5-FU cells to 5-fluorouracil and in-hibited cells proliferation via down-regulating Bcl-2 expression.