miR-181a/b靶向抑制多种抗凋亡蛋白表达对肺癌细胞顺铂耐药的影响

miR-181a/b modulates cisplatin resistance of human lung cancer cell by targeting multiple anti-apoptosis genes

目的:研究miR-181a/b在肺癌细胞顺铂耐药形成中的作用。方法:运用miRNA实时定量PCR方法检测miR-181a/b在肺癌顺铂耐药细胞A549/CDDP与母代A549细胞中的表达差异,运用Western blot检测A549/CDDP细胞与母代细胞抗凋亡蛋白BCL2、MCL1和XIAP的表达差异,分别构建BCL2、MCL1和XIAP的3′UTR荧光素酶报告质粒验证miR-181a/b的靶基因,在耐药细胞中瞬时转染miR-181a/b模拟物以检测上调miR-181a/b对A549/CDDP细胞中BCL2、MCL1和XIAP蛋白表达及耐药性的影响,并运用流式细胞术检测转染后耐药细胞对CDDP(Cisplatin,顺铂)诱导凋亡的影响。结果:在A549/CDDP细胞中miR-181a/b均呈低表达,而抗凋亡蛋白BCL2、MCL1和XIAP则呈高表达,荧光素酶报告实验证实BCL2、MCL1和XIAP是直接受miR-181a/b调控的靶基因,在耐药细胞中上调miR-181a/b显著抑制BCL2、MCL1和XIAP蛋白表达水平,显著增加耐药细胞对顺铂的敏感性,并显著增加耐药细胞对顺铂诱导的凋亡。结论:miR-181a/b靶向抑制多种抗凋亡蛋白表达可显著增加A549/CDDP细胞对顺铂的敏感性。

Objective：To investigate the possible role of miR-181a / b in the development of cisplatin resistance in human lung cancer cell line A549 / CDDP.Methods：Using quantitative real-time PCR analysis for miRNA and Western blot to detect the expression of miR-181a / b and anti-apoptotic protein BCL2,MCL1 and XIAP in cisplatin resistant human lung cancer cell line A549 / cisplatin（CDDP） and its parental A549 cell,respectively.The luciferase reporter plasmids carried 3＇-untranslated region of BCL2,MCL1 and XIAP were constructed to testify the target genes of miR-181a / b,respectively.Using transient transfection of miR-181a / b to mimic the up-regulation of miR-181a / b in A549 / CDDP cells and observe the effect of miR-181a / b on the expression level of BCL2,MCL1,XIAP and cisplatin resistance phenotype.Using flow cytometry to detect CDDP-induced apoptosis of the A549 / CDDP cells after the transfection.Results：miR-181a / b was down-regulated in cisplatin-resistant human lung cancer cell line A549 / CDDP,the down-regulation of miR-181a / b was concurrent with the over-expression of its targeted anti-apoptotic genes BCL2,MCL1 and XIAP in A549 / CDDP cells,compared to the parental A549 cell line.The luciferase activity of BCL2,MCL1 and XIAP 3＇-untranslated region-based reporters construct in A549 / CDDP cells suggested that BCL2,MCL1 and XIAP were the common target genes of the miR-181a / b.Over-expression of miR-181a / b sensitized A549 / CDDP cells to CDDP.Overexpression of miR-181a / b also inhibited the expression of BCL2,MCL1 and XIAP and sensitized A549 / CDDP cells to CDDP-induced apoptosis.Conclusion：miR-181a / b could enhance the sensitivity of cisplatin in human lung cancer cell line A549 / CDDP,at least in part,by modulation of apoptosis via targeting multiple anti-apoptosis genes.