论文部分内容阅读
目的 探讨EGCG对鼻咽癌细胞激活蛋白 1(AP 1)信号转导通路的干预作用 ,阐明在鼻咽癌细胞中茶多酚干预EB病毒潜伏膜蛋白 1(LMP1)活化的AP 1信号转导通路中靶分子的机制。方法 采用EB病毒阴性及阳性的鼻咽癌细胞系CNE1和CNE1 LMP1细胞。利用四甲基偶氮唑蓝(MTT)法观察EGCG对CNE1和CNE1 LMP1细胞的生存率的影响。采用瞬间转染及报道基因法观察EGCG对AP 1活性的作用。利用间接免疫荧光法观察EGCG对JNK核移位的影响 ,再分别提取CNE1和CNE1 LMP1的胞浆及胞核蛋白 ,Westernblot分析EGCG抑制JNK的核移位后 ,胞浆及胞核蛋白中JNK的变化。采用Westernblot分析EGCG对c Jun的磷酸化水平的影响。采用瞬间转染及报道基因法观察EGCG对cyclinD1启动子活性的影响 ,并用Westernblot分析EGCG对cyclinD1蛋白表达的作用。结果 EGCG对鼻咽癌细胞的抑制作用有剂量依赖性 ,并可抑制AP 1的活性。EGCG能抑制JNK的核移位 ,并抑制c Jun的磷酸化。EGCG对AP 1信号通路下游的靶基因cyclinD1的启动子活性及其蛋白表达都有抑制作用。结论 EGCG对信号转导通路上的AP 1、JNK、c Jun、cyclinD1多个靶点分子具有干预作用。LMP1是EB病毒这种编码的蛋白 ,因此 ,EGCG抑制与病毒相联系的信号转导通路 ,可能是EGCG抑制与病毒相关的肿瘤的分子机
OBJECTIVE: To investigate the effect of EGCG on AP 1 signal transduction pathway in nasopharyngeal carcinoma cells and to elucidate the effect of tea polyphenols on activation of AP 1 signal transduction by Epstein-Barr virus latent membrane protein 1 (LMP1) in nasopharyngeal carcinoma cells Mechanism of target molecules in the pathway. Methods EBV-negative and positive nasopharyngeal carcinoma cell lines CNE1 and CNE1 LMP1 cells were used. The effect of EGCG on the survival rate of CNE1 and CNE1 LMP1 cells was observed by MTT assay. Transient transfection and reporter gene method was used to observe the effect of EGCG on AP1 activity. The effect of EGCG on nuclear translocation of JNK was observed by indirect immunofluorescence. Cytoplasmic and nuclear proteins of CNE1 and CNE1 LMP1 were extracted respectively. Western blot analysis showed that JNK in cytoplasm and nucleoprotein Variety. Western blot was used to analyze the effect of EGCG on c Jun phosphorylation. The effect of EGCG on cyclinD1 promoter activity was observed by transient transfection and reporter gene method, and the effect of EGCG on cyclinD1 protein expression was analyzed by Western blot. Results The inhibitory effect of EGCG on nasopharyngeal carcinoma cells in a dose-dependent manner, and inhibited the activity of AP 1. EGCG inhibits JNK nuclear translocation and inhibits c Jun phosphorylation. EGCG can inhibit the promoter activity of cyclinD1 and its protein expression downstream of AP1 signaling pathway. Conclusion EGCG can interfere with many target molecules of AP 1, JNK, c Jun, cyclinD1 in signal transduction pathway. LMP1 is a protein encoded by Epstein-Barr virus. Therefore, the inhibitory effect of EGCG on the virus-associated signal transduction pathway may be the molecular mechanism by which EGCG inhibits virus-associated tumors