EGCG may inhibit nasopharyngeal carcinoma through interfering with Epstein-Barr Virus. - GreenMedInfo Summary
[Epigallocatechin-3-gallate interferes with EBV-encoding AP-1 signal transduction pathway].
Zhonghua Zhong Liu Za Zhi. 2004 Jul;26(7):393-7. PMID: 15355641
OBJECTIVE: To elucidate the interference effect of Epigallocatechin-3-Gallate (EGCG) on targets of Activator Protein-1 (AP-1) signal transduction pathway activated by EB virus encoded latent membrane protein 1 in nasopharyngeal carcinoma (NPC) cell lines. METHODS: Survival rate of cells was determined by MTT assay. AP-1 and CyclinD1 activation were analyzed by promoter luciferase reporter system. Nuclear translocation of JNK was analyzed by indirect immunofluorescence. Protein expression and phosphorylation were observed by Western blot. RESULTS: EGCG inhibited the survival of CNE1 and CNE-LMP1 cells and the activity of AP-1 caused by LMP1 in CNE-LMP1 cells. EGCG also inhibited the nuclear translocation of JNK and the phosphorylation of c-Jun. It also inhibited cyclinD1 promoter activity and cyclinD1 expression. CONCLUSION: EGCG inhibits AP-1, JNK, c-Jun and cyclinD1 which are key targets on AP-1 signal transduction pathway. The results may explain the molecular mechanism of action of EGCG against nasopharyngeal carcinoma.