Epigallocatechin-3-gallate up-regulates tumor suppressor gene expression via a reactive oxygen species-dependent down-regulation of UHRF1.
Fiche publication
Date publication
juillet 2012
Auteurs
Membres identifiés du Cancéropôle Est :
Dr BRONNER Christian, Dr HAMICHE Ali, Dr MULLER Christian, Pr SCHINI-KERTH Valérie, Dr MOUSLI Marc
Tous les auteurs :
Achour M, Mousli M, Alhosin M, Ibrahim A, Peluso J, Muller CD, Schini-Kerth VB, Hamiche A, Dhe-Paganon S, Bronner C
Lien Pubmed
Résumé
Ubiquitin-like containing PHD and RING finger 1 (UHRF1) contributes to silencing of tumor suppressor genes by recruiting DNA methyltransferase 1 (DNMT1) to their hemi-methylated promoters. Conversely, demethylation of these promoters has been ascribed to the natural anti-cancer drug, epigallocatechin-3-gallate (EGCG). The aim of the present study was to investigate whether the UHRF1/DNMT1 pair is an important target of EGCG action. Here, we show that EGCG down-regulates UHRF1 and DNMT1 expression in Jurkat cells, with subsequent up-regulation of p73 and p16(INK4A) genes. The down-regulation of UHRF1 is dependent upon the generation of reactive oxygen species by EGCG. Up-regulation of p16(INK4A) is strongly correlated with decreased promoter binding by UHRF1. UHRF1 over-expression counteracted EGCG-induced G1-arrested cells, apoptosis, and up-regulation of p16(INK4A) and p73. Mutants of the Set and Ring Associated (SRA) domain of UHRF1 were unable to down-regulate p16(INK4A) and p73, either in the presence or absence of EGCG. Our results show that down-regulation of UHRF1 is upstream to many cellular events, including G1 cell arrest, up-regulation of tumor suppressor genes and apoptosis.
Référence
Biochem Biophys Res Commun. 2012 Jul 3.