NF-κB介导的EBV-LMP1在Rat-1细胞转化和成瘤中的作用  

Effects of Epstein-Barr Virus Latent Membrane Protein 1 Mediated by Nuclear Factor-κB on Transformation and Tumorigenesis of Rat-1 Cells

作　　者：张志伟[1] 贺智敏[1] 周敏[1] 张琼[1] 余艳辉[1] 陈主初[1] 

机构地区：[1]中南大学湘雅医学院肿瘤研究所,湖南长沙410078

出　　处：《癌症》2007年第2期118-122,共5页Chinese Journal of Cancer

基　　金：国家自然科学基金(No.30470668)~~

摘　　要：背景与目的:EB病毒潜伏性膜蛋白1(latent membrane protein1,LMP1)是病毒基因组编码的致瘤蛋白。本研究拟探讨LMP1在细胞转化和致瘤过程中的作用机制。方法:采用基因重组方法构建LMP1和显性负突变IκBα逆转录病毒质粒pLNSX-LMP1和pBabe-IκBα,分别与含有转录因子NF-κB启动子的荧光素酶表达质粒共转染293细胞,单光子检测仪测定LMP1对NF-κB的活化作用及IκBα对NF-κB的抑制作用;同时将2种重组病毒载体分别导入PA317细胞包装,获取2种逆转录病毒(retrovirus,RV),单独(RV-LMP1)或先后(先RV-LMP1后RV-IκBα)感染体外培养的Rat1细胞,检测转导细胞的集落形成能力及裸鼠成瘤能力。结果:当pBabe-IκBα与pLNSX-LMP1以1∶1共转染,IκBα能使LMP1活化NF-κB的作用降低75%;当以3∶1共转染,LMP1的活化作用几乎全部被抑制。IκBα能明显抑制RV-LMP1感染细胞的恶性表型:平皿克隆形成数从368±7和287±17分别降至59±6和8±2(n=3,P<0.001);软琼脂集落形成数从477±13和347±10分别降至61±15和95±7(n=3,P<0.001);裸鼠成瘤能力显著降低,瘤体积自(1.61+0.23)cm3降至(0.20±0.08)cm3(n=5,P<0.001)。结论:EB病毒LMP1促Rat1细胞恶性转化作用主要依赖NF-κB的活化。BACKGROUND ＆ OBJECTIVE： Epstein-Barr virus （EBV） latent membrane protein 1 （LMP1） is an oncoprotein coded by EBV genome. This study was to investigate the effects of EBV LMP1 on transformation and tumorigenesis of Rat-1 cells. METHODS： Retrovirus plasmids pLNSX-LMP1 and pBabe-IκBα constructed by gene recombination technique, were cotransfected respectively with nuclear factor-κB luciferase reporter （pNF-κB- luc） into 293 cells. The actions of LMP1 in activating NF-κB and IκBαin inhibiting NF-κB were measured by luciferase activity assay. Moreover, pLNSX-LMP1 and pBabe-IκBαwere transfected respectively into the ecotropic retrovirus packaging cell line PA317 to generate LMP1 retrovirus （RV-LMP1） and IκBαretrovirus （RV-IκBα. After Rat-1 cells were infected by RV-LMP1 alone or RV-LMP1 combined RV-IκBα their malignant transformation phenotype was detected by colony forming assay and nude mice tumorigenicity assay. RESULTS： When pLNSX-LMP1 and pBabe-IκB were cotransfected at a ratio of 1：1, IκBα inhibited LMPl-mediated NF-κB activation by 75%; and at a ratio of 3：1, it almost completely inhibited LMPl-mediated NF-κB activation. IκBαobviously inhibited LMPl-mediated malignant phenotype of Rat-1 cells.colony formation number on plates were significantly decreased from （368±7）/well and （287±17）/well to （59±6）/well and （8±2）/well （P〈0.001）. Foci in soft agarose were decreased from （477±13）/well and （347±10）/well to （61±15） /well and （95±7）/well （P〈0.001）. The ability of tumorigenicity in nude mice was markedly decreased= tumor volume was decreased from （1.61 ±0.23） cm^3 to （0.20±0.08） cm^3 （P〈0.001）. CONCLUSION= EBV-LMP1 could lead to transformation and tumorigenesis of Rat-1 cells by activating NF-κB.

关 键 词：NF-ΚB IΚBΑ 潜伏性膜蛋白1 细胞转化 病理学 

分 类 号：R730.2[医药卫生—肿瘤]