siRNA沉默PTTG基因对人胰腺癌细胞PANC-1细胞凋亡的影响

目的研究PTTG基因沉默对胰腺癌细胞凋亡的影响,初步探讨其调控机制。方法利用阳离子脂质体进行基因沉默实验,将PANC-1细胞分为三组（①.未转染PANC-1细胞、②.转染阴性对照siRNA、③转染siRNA-PTTG）,TUNEL染色法检测细胞凋亡;RT-PCR和Western blot技术检测bcl-2,bax基因和蛋白表达;ELISA法检测caspase-3活性。结果组③细胞凋亡明显增多,凋亡率为18.4±2.4%;组①和组②凋亡率分别为7.5±2.0%和6.9±1.1%,差异具有显著性（P〈0.05）;组③bcl-2 mRNA和蛋白表达水平下降,与组①和组②比较差异具有统计学意义（P〈0.05）;组③、组①和组②间bax mRNA和蛋白表达没有具有统计学差异（P〈0.05）;组③caspase-3活性升高,与组①和组②比较差异具有统计学意义（P〈0.05）。结论 siRNA-PTTG下调PTTG基因表达导致PANC-1细胞凋亡增加,可能与bcl-2表达下调,caspase-3活性升高有关。

Effects of RNAi silencing PTTG gene on the apoptosis of human pancreatic cancer cell PANC-1

Objective To investigate the effect of small interference RNA（siRNA） targeting PTTG gene on the apoptosis of pancreatic cancer cell line PANC-1.Methods The chemically synthesized siRNA-PTTG was transferred into cultured PANC-1 cell in vitro by Lipofectamine.PANC-1cells were divided into three groups as following：①untreated cell ②negative control siRNA ③siRNA-PTTG transfection.Cell apoptosis was examined with TUNEL in situ staining kit.The expression of bcl-2 and bax were detected by RT-PCR and Western blot.The activity of caspase-3 was determined by enzyme-linked immunosorbent assay（ELISA）.Results The percentage of apoptotic cells in group③ was higher than those of group① and ②（18.4±2.4% vs 7.53±2.0% vs 6.9±1.1%）,there was statistic significance between them（P0.05）.The relative level of bcl-2 mRNA and protein in group③ were decreased,there was statistic significance between group③ and group① and ②（P0.05）.Compared with group① and ②,the activity of caspase-3 of group③was increased dramatically（P0.05）.Conclusion The expression of bcl-2 was down-regulated and the activity of caspase-3 was activated,which may contribute the apoptosis induction after PTTG silencing.