Abstract
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.
Materials and 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.
Conclusion:
These results suggest the potential therapeutic use of EGCG for the reversal of WIF-1 promoter methylation.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing / genetics*
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Adaptor Proteins, Signal Transducing / metabolism
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Anticarcinogenic Agents / pharmacology*
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Blotting, Western
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Carcinoma, Non-Small-Cell Lung / drug therapy
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Carcinoma, Non-Small-Cell Lung / genetics*
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Carcinoma, Non-Small-Cell Lung / metabolism
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Catechin / analogs & derivatives*
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Catechin / pharmacology
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Cell Line, Tumor
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Cell Proliferation / drug effects
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DNA Methylation / drug effects*
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Epigenesis, Genetic
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Gene Expression Regulation, Neoplastic / drug effects
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Humans
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Luciferases / metabolism
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Lung Neoplasms / drug therapy
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Lung Neoplasms / genetics*
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Lung Neoplasms / metabolism
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Promoter Regions, Genetic / drug effects*
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Promoter Regions, Genetic / genetics
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Repressor Proteins / genetics*
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Repressor Proteins / metabolism
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Reverse Transcriptase Polymerase Chain Reaction
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Urokinase-Type Plasminogen Activator / antagonists & inhibitors
Substances
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Adaptor Proteins, Signal Transducing
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Anticarcinogenic Agents
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RNA, Messenger
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Repressor Proteins
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WIF1 protein, human
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Catechin
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epigallocatechin gallate
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Luciferases
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Urokinase-Type Plasminogen Activator