PKR、eIF-2α在 IL-24诱导胶质瘤细胞凋亡中的作用研究

摘要

目的：探讨白细胞介素24（interleukin-24，IL-24）对胶质瘤细胞凋亡的影响以及双链RNA蛋白激酶R （double-stranded RNA-dependent protein kinase，PKR）、真核细胞翻译起始因子2α（eukaryotic initiation factor 2α， eIF-2α）在其中的作用。方法将载有 IL-24基因的 Ad5F35型重组腺病毒（Ad-IL-24）及载有增强绿色荧光蛋白（enhanced green fluorescent protein，EGFP）基因作为对照的 Ad5F35型重组腺病毒（Ad-EGFP）转染入胶质瘤细胞U87和 U251中，应用流式细胞仪检测胶质瘤细胞 U87和 U251中的凋亡情况，并检测 U87和 U251各组中 PKR、磷酸化 PKR（phosphorylation-PKR，pPKR）、eIF-2α及磷酸化 eIF-2α（phosporylation-eIF-2α，peIF-2α）的表达情况。结果在胶质瘤细胞 U87和 U251中转染 IL-24后的细胞凋亡率为12．3％和13．0％，明显高于空白组与对照组，并且转染 IL-24的胶质瘤细胞中 PKR、pPKR、eIF-2α及 peIF-2α的表达增加。结论 IL-24可能在胶质瘤细胞中通过上调 PKR、eIF-2α的表达及其活化，促进胶质瘤细胞凋亡。%Objective To investigate the regulation of interleukin-24 (IL-24 )indouble-stranded RNA-dependent protein kinase(PKR),eukaryotic initiation factor 2α(eIF-2α)-induced apoptosis of glioma cells.Methods Adenovirus Ad5F35-IL24(Ad-IL-24)and the control virus Ad5F35-enhanced green fluorescent protein (Ad-EGFP)were transfected into U87 and U251 glioma cells.Then,U87 and U251 glioma cell apoptosis were tested using flow cytometry,and the expression of PKR,phosphorylation-PKR(pPKR),eIF-2αand phosporylation eIF-2α(peIF-2α)in U87 and U251 of different groups were detected by western blot.Results The cell apoptosis rates were significantly increased to 12.3% and 13.0% in U87 and U251 glioma cells after being transfected with IL-24,and the expression of PKR,pPKR,eIF-2α and peIF-2α increased after being transfected with IL-24 in glioma cells.Conclusion IL-24 may regulate PKR,eIF-2αexpression and activation to promote apoptosis of glioma cells.