微小核糖核酸miR-449a对前列腺癌细胞凋亡的影响

摘要

目的 探究微小RNA(miRNA-449a)在前列腺癌中的表达及其对前列腺癌细胞凋亡的影响.方法 对前列腺细胞系作不同处理:阴性对照组[转染随机序列(dsControl)]和实验组(转染miR-449a).采用实时荧光定量聚合酶链反应(qPCR)检测前列腺癌组织及细胞中miR-449a的表达;流式细胞术测定不同转染组细胞凋亡情况;Western blot检测各处理组细胞中凋亡相关蛋白Bcl-2、Bax、Caspase 3及Cleaved caspase-3的表达.结果 qPCR结果显示,miR-449a信使RNA水平在前列腺癌组织与癌旁组织比较,表达下降(0.481±0.055、0.951士0.039),差异有统计学意义(P＜0.05);miR-449a信使RNA水平在前列腺癌细胞系PC3和DU145中较RWPE-1细胞中表达也明显下调(0.967±0.062、0.24±0.07、0.493±0.089),差异有统计学意义(P＜0.05).流式细胞术检测细胞凋亡显示,对照组和实验组中PC3细胞的凋亡率分别为(4.827±0.756)％、(21.691±1.813)％,与对照组相比,差异有统计学意义(F=43.32,P＜0.05);DU145细胞的凋亡率分别为(3.79±0.72)％、(13.88±0.712)％,与对照组相比,差异有统计学意义(F=483.22,P＜0.05).Western blot检测结果验证了不同处理组PC3和DU145细胞中,Bcl-2蛋白表达下降,而Bax、Caspase-3及Cleaved caspase-3表达上调,差异具有统计学意义(P＜0.05).结论 miR-449a可能通过下调Bcl 2蛋白的表达,发挥诱导前列腺癌细胞凋亡的作用.%Objective To investigate the expression of micro RNA-449a (miRNA-449a) and its effects on the apoptosis of prostate cancer (PCa) cells.Methods The PCa cell lines were divided into the negative control group and experimental group.The expression of miR-449a in prostate cancer tissues and cells was detected with real-time fluorescence quantitative polymerase chain reaction (qPCR).Apoptosis was detected with flow cytometry.The expressions of apoptosis-related proteins,including Bcl-2,Bax,Caspase-3 and Cleaved caspase-3,were detected with Western blot.Results The mRNA expression of miR-449a was significantly lower in PCa tissues than in adjacent tissues (0.481±0.055 vs.0.951±0.039),and the difference was significant (P＜0.05).The mRNA expression of miR-449a in PCa cell lines PC3,DU145 and LnCap were significantly lower than that in RWPE-1 cells (0.967 ± 0.062,0.24 ± 0.07,0.493 ± 0.089,0.431 ± 0.088),and the difference was significant (P＜0.05).Flow cytometry showed that the apoptotic rates of PC3 and DU145 cells in the control and experimental groups were (4.827±0.756) ％,(21.691 ± 1.813) ％,(3.79±0.72) ％ and (13.88±0.712) ％,respectively,and the difference was statistically significant (F=43.32,P＜0.05),(F =483.22,P＜0.05).Western blot showed that the protein expression of Bcl-2 was down-regulated,while the expressions of Bax,Caspase-3 and Cleaved caspase-3 were up-regulated in PC3 and DU145 cells,and the difference was significant (P＜0.05).Conclusion MiR-449a may play an important role in inducing the apoptosis of prostate cancer cells by down-regulating the expression of Bcl-2 protein.