Livin靶向RNA干扰对MDA-MB-231细胞增殖和凋亡的影响

目的 研究凋亡抑制蛋白Livin靶向RNA干扰MDA-MB-231对细胞增殖和凋亡的影响,探讨其可能的机制.方法 构建3个靶向Livin的siRNA真核表达载体,分别转染乳腺癌细胞MDA-MB-231后,通过RT-PCR、Western blot技术检测干扰前后MDA-MB-231细胞Livin、Caspase-3和Smac/DIABLO在mRNA、蛋白水平的表达;采用MTT法检测对细胞增殖的抑制作用,流式细胞法测细胞周期,TUNEL法检测细胞凋亡以及观察细胞形态变化.结果 成功构建了针对Livin基因的3个特异性siRNA表达载体.它们不同程度地抑制了MDA-MB-231细胞Livin基因的表达,以si-Livin2抑制效率最高,它对Livin的mRNA和蛋白的抑制率分别达76.4%,70.2%.si-Livin2转染48 h后,与未转染组相比,细胞增殖活力受到抑制,转染48 h抑制率达36.1%.细胞周期重新分布,G0/G1期上升为(71.75±1.31)%,S期下降为(18.06±1.46)%;细胞凋亡率上升为(13.28±1.65)%;电镜下可见典型的凋亡细胞特征.细胞内Caspase-3,Smac/DIABLO的mRNA、蛋白表达有所上升.结论 Livin靶向RNA干扰通过上调Caspase-3,Smac/DIABLO表达有效地抑制MDA-MB-231细胞增殖,促进凋亡.

Effects of RNAi targeting Livin on proliferation and apoptosis of MDA-MB-231 cells

Objective To study the mechanisms by which the RNA targeting Livin regulates the proliferation and apoptosis of MDA-MB-231 cells. Methods Three siRNA eukaryotic expression vectors targeting Livin were constructed and transfected into breast cancer MDA-MB-231 cells. The changes of Livin, Caspase-3 and Smac/DIABLO expressions in MDA-MB-231 cells with or without RNAi transfection were detected by quantitative Real-Time PCR and Western blotting. The proliferation of MDA-MB-231 cells was detected by MTT assay, t...