title: Epigenetic modifications of the Estrogen receptor beta gene in epithelial ovarian cancer cells.
abstract: BACKGROUND
  The mechanisms of estrogen insensitivity or estrogen resistance in ovarian cancer cells are not known. Studies on regulation of the estrogen receptor (ER) gene have suggested a role for epigenetics in silencing ER expression.
  
  
  METHODS
  Cells from insensitive ovarian cancer cells, SKOV3 and HEY, were cultured with and without the DNA methyltransferase (DNMT) inhibitor, 5-aza-2'-deoxycytidine (AzaC) and the histone deacetylase (HDAC) inhibitor, trichostatin (TSA). ERbeta promoter methylation was examined using bisulfite sequencing. RNA was collected for oligonucleotide array studies.
  
  
  RESULTS
  Cell type-specific ERbeta promoter methylation was found as well as relative hypomethylation of the ERbeta promoter in SKOV3 compared to HEY cells. Preferential demethylation of specific CpGs by different treatments was found. AzaC and TSA resulted in significant tumor growth inhibition and alterations in expression of numerous genes.
  
  
  CONCLUSIONS
  The ERbeta promoter is differentially methylated in ovarian cancer cells. Moreover, AzaC and TSA can inhibit ovarian cancer cell growth.
authors.affiliation: Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA 30310, USA.
authors.forename: Oi Wah Stephanie
authors.initials: OW
authors.lastname: Yap
authors.forename: Ganapathy
authors.initials: G
authors.lastname: Bhat
authors.forename: Liang
authors.initials: L
authors.lastname: Liu
authors.forename: Trygve O
authors.initials: TO
authors.lastname: Tollefsbol