蛋白酶体抑制剂通过内质网应激诱导DU145细胞凋亡机制的探讨  

Mechanism of proteasome inhibitor epoxomicin inducing DU145 cell apoptosis

作　　者：王利平[1] 罗荣城[1] 符鹏程[2] 黄朝刚[2] 罗迪贤[2] 

机构地区：[1]南方医科大学中西医结合医院肿瘤中心,广东广州510315 [2]湖南郴州市第一人民医院肿瘤科,湖南郴州423000

出　　处：《中国现代医学杂志》2015年第8期6-11,共6页China Journal of Modern Medicine

基　　金：国家自然科学基金(No:81372825);郴州市第一人民医院青年基金(No:N2013-009)

摘　　要：目的探讨蛋白酶体抑制剂(EPO)诱导前列腺癌DU145细胞凋亡机制是否与内质网应激(Er-stress)有关。方法用不同浓度的EPO处理DU145细胞,MTS检测细胞生长情况;流式细胞仪检测细胞凋亡率;实时定量聚合酶链反应(Real-time PCR)检测Er-stress相关分子同源蛋白质(CHOP)、葡萄糖调节蛋白78(GRP78)、X盒结合蛋白1(XBP-1)、剪接型X盒结合蛋白1信使核糖核酸(XBP-1s m RNA);Western blot检测CHOP和GRP78的表达。结果 EPO抑制DU145细胞生长,并且呈现浓度梯度依赖性,处理组细胞凋亡率高于未处理组,高剂量组凋亡率高于低剂量组。EPO处理后,CHOP、剪接型X盒结合蛋白1(XBP-1s)、GRP78 m RNA明显升高,72 h最明显。低剂量组与高剂量组48 h CHOP和XBP-1s的表达比较差异均有统计学意义,两组48和72 h GRP78比较差异均有统计学意义。EPO处理后,XBP-1和XBP-1s基因转录水平升高,而XBP-1s随处理时间增长基因转录水平变化不明显。EPO处理后,CHOP和GRP78不断增加,72 h两种蛋白质均达到最高值,并且低剂量组与高剂量组在72 h比较差异有统计学意义。结论 EPO能抑制DU145细胞生长,诱导凋亡,其机制可能与激活Er-stress,诱发内质网的相关分子CHOP、XBP-1s、XBP-1、GRP78的表达有关。[Objective] To investigate the mechanism of proteasome inhibitor epoxomicin （EPO） inducing the apoptosis of DU145 cells and its relationship with endoplasmic reticulum （ER） stress. [Methods] DU145 cells were treated by different doses of EPO. Cell proliferation was detected using MTS reagent and apoptosis was examined by flow cytometer. ER-stress associated molecules including homologous protein （CHOP）, glu- coseregulatedprotein 78 （CRP78）, X-box binding protein 1 （XBP-1） and X-box binding proteinlspliced mRNA （XBP-ls mRNA） were tested by real-time PCR and the proteins of CHOP and GRP78 were analyzed by Western blot. [Results] DU145 cell proliferation was inhibited by EPO in a time and dose-dependent manner. The percentages of cell apoptosis in the treatment groups and the high-dose group were higher than those of the control group and the low-dose group. CHOP, XBP-ls and GRP78 mRNA were notably increased with time, reached the highest level at 72 hour of treatment. The expressions of CHOP and XBP-ls were significantly different between the low-dose and the high-dose groups at 48 hour, while GRP78 mRNA had a sig- nificant difference between both groups at 48 and 72 hour. XBP-1 and XBP-ls mRNA were all elevated with EPO for different hours. At the same time, XBP-ls mRNA expression was raised with time, whereas the XBP-ls had little change with time. The proteins of CHOP and GRP78 were increased constantly in DU145 cells with the treatment of EPO, which had the highest increase at 72 hour and a distinct difference between the low-dose and the high-dose groups. [Conclusion] The proteasome inhibitor EPO could inhibit the growth and induce apoptosis of DU145 cells. The mechanism may be related to the activation of ER-stress which induces the expressions of ER-associated molecules such as CHOP, XBP-ls, XBP-1 and GRP78.

关 键 词：蛋白酶体抑制剂 同源蛋白质 葡萄糖调节蛋白78 剪接型X盒结合蛋白1 内质网应激 

分 类 号：R737.25[医药卫生—肿瘤]