Promoter demethylation of WIF-1 by epigallocatechin-3-gallate in lung cancer cells.
BACKGROUND
Aberrant promoter methylation of Wnt inhibitory factor-1 (WIF-1) is a fundamental mechanism of epigenetic silencing in human cancers. Epigallocatechin-3-gallate (EGCG) has been reported to directly reactivate several methylation-silenced genes. The promoter demethylation and reactivation of WIF-1 has not previously been reported.


METHODS
Methylation-specific PCR, sequencing analysis and RT-PCR analysis were performed to evaluate promoter demethylation of WIF-1 and WIF-1 expression, Western blot analysis and luciferase reporter assay were performed to evaluate expression of cytosolic beta-catenin protein and Tcf/Lef reporter activity.


RESULTS
Promoter demethylation of WIF-1 and restoration of WIF-1 expression after EGCG treatment are demonstrated in H460 and A549 cell lines. EGCG also decreased cytosolic beta-catenin protein level and inhibited Tcf/Lef reporter activity.


CONCLUSIONS
These results suggest the potential therapeutic use of EGCG for the reversal of WIF-1 promoter methylation.
Gao
Zhi
Z
Department of Cardiothoracic Surgery, Beijing Friendship Hospital, Beijing, P.R.C.
Xu
Zhidong
Z
Hung
Ming-Szu
MS
Lin
Yu-Ching
YC
Wang
Tianyou
T
Gong
Min
M
Zhi
Xiuyi
X
Jablon
David M
DM
You
Liang
L
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics* / Q000378:metabolism; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019175:DNA Methylation / Q000187:drug effects*; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors
D048868:Adaptor Proteins, Signal Transducing; D016588:Anticarcinogenic Agents; D012333:RNA, Messenger; D012097:Repressor Proteins; C485569:WIF1 protein, human; D002392:Catechin; C045651:epigallocatechin gallate; D008156:Luciferases; D014568:Urokinase-Type Plasminogen Activator