title: Genome-wide DNA methylation analysis reveals phytoestrogen modification of promoter methylation patterns during embryonic stem cell differentiation.
abstract: BACKGROUND
  Environmental challenges during development affect the fetal epigenome, but the period(s) vulnerable to epigenetic dysregulation is(are) not clear. By employing a soy phytoestrogen, genistein, that is known to alter the epigenetic states of the A(vy) allele during embryogenesis, we have explored the sensitive period for epigenetic regulation. The post-implantation period, when de novo DNA methylation actively proceeds, is amenable to in vitro analysis using a mouse embryonic stem (ES) cell differentiation system.
  
  
  RESULTS
  Mouse ES cells were differentiated in the presence or absence of genistein, and DNA methylation patterns on day 10 were compared by microarray-based promoter methylation analysis coupled with a methylation-sensitive endonuclease (HpaII/McrBC)-dependent enrichment procedure. Moderate changes in methylation levels were observed in a subset of promoters following genistein treatment. Detailed investigation of the Ucp1 and Sytl1 promoters further revealed that genistein does not affect de novo methylation occurring between day 0 and day 4, but interferes with subsequent regulatory processes and leads to a decrease in methylation level for both promoters.
  
  
  CONCLUSIONS
  Genistein perturbed the methylation pattern of differentiated ES cells after de novo methylation. Our observations suggest that, for a subset of genes, regulation after de novo DNA methylation in the early embryo may be sensitive to genistein.
authors.affiliation: Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan. nsato.epi@mri.tmd.ac.jp
authors.forename: Noriko
authors.initials: N
authors.lastname: Sato
authors.forename: Naomi
authors.initials: N
authors.lastname: Yamakawa
authors.forename: Moe
authors.initials: M
authors.lastname: Masuda
authors.forename: Katsuko
authors.initials: K
authors.lastname: Sudo
authors.forename: Izuho
authors.initials: I
authors.lastname: Hatada
authors.forename: Masaaki
authors.initials: M
authors.lastname: Muramatsu
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D018899:CpG Islands; D004247:DNA / Q000235:genetics; D019175:DNA Methylation; D053595:Embryonic Stem Cells / Q000166:cytology; D004777:Environment; D044127:Epigenesis, Genetic; D019833:Genistein / Q000494:pharmacology; D016678:Genome; D051379:Mice; D008810:Mice, Inbred C57BL; D048789:Phytoestrogens / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013025:Glycine max
chemical_list: D048789:Phytoestrogens; D004247:DNA; D019833:Genistein