title: Transcriptional activation of steroidogenic factor-1 by hypomethylation of the 5' CpG island in endometriosis.
abstract: BACKGROUND
  Endometriosis is an estrogen-dependent disease. Steroidogenic factor-1 (SF-1), a transcriptional factor essential for activation of multiple steroidogenic genes for estrogen biosynthesis, is undetectable in normal endometrial stromal cells and aberrantly expressed in endometriotic stromal cells.
  
  
  OBJECTIVE
  The objective of the study was to unravel the mechanism for differential SF-1 expression in endometrial and endometriotic stromal cells.
  
  
  METHODS
  We identified a CpG island flanking the SF-1 promoter and exon I region and determined its methylation patterns in endometrial and endometriotic cells.
  
  
  METHODS
  The study was conducted at Northwestern University.
  
  
  METHODS
  Eutopic endometrium from disease-free subjects (n = 8) and the walls of cystic endometriosis lesions of the ovaries (n = 8) were investigated.
  
  
  METHODS
  Stromal cells were isolated from these two types of tissues.
  
  
  METHODS
  Measures are mentioned in Results.
  
  
  RESULTS
  SF-1 mRNA and protein levels in endometriotic stromal cells were significantly higher than those in endometrial stromal cells (P < 0.001). Bisulfite sequencing showed strikingly increased methylation in endometrial cells, compared with endometriotic cells (P < 0.001). Demethylation by 5-aza-2'-deoxycytidine increased SF-1 mRNA levels by up to 55.48-fold in endometrial cell (P < 0.05). Luciferase assays showed that the -85/+239 region bearing the CpG island regulated its activity (P < 0.01). Natural or in vitro methylation of this region strikingly reduced SF-1 promoter activity in both cell types (P < 0.01). Chromatin immunoprecipitation assay showed that methyl-CpG-binding domain protein 2 binds to the SF-1 promoter in endometrial but not endometriotic cells.
  
  
  CONCLUSIONS
  This is the first demonstration of methylation-dependent regulation of SF-1 in any mammalian tissue. These findings point to a new mechanism for targeting local estrogen biosynthesis in endometriosis.
authors.affiliation: Division of Reproductive Biology Research, Department of Obstetrics and Gynecology, Northwestern University, Chicago, Illinois 60611, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Xue
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Lin
authors.forename: Ping
authors.initials: P
authors.lastname: Yin
authors.forename: Magdy P
authors.initials: MP
authors.lastname: Milad
authors.forename: You-Hong
authors.initials: YH
authors.lastname: Cheng
authors.forename: Edmond
authors.initials: E
authors.lastname: Confino
authors.forename: Scott
authors.initials: S
authors.lastname: Reierstad
authors.forename: Serdar E
authors.initials: SE
authors.lastname: Bulun
mesh_terms: D001141:Aromatase / Q000096:biosynthesis; D047072:Aromatase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D015153:Blotting, Western; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D000077209:Decitabine; D004715:Endometriosis / Q000235:genetics*; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D017930:Genes, Reporter / Q000235:genetics; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics*; D006801:Humans; D047468:Immunoprecipitation; D008156:Luciferases / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics / Q000502:physiology*; D014162:Transfection
chemical_list: D047072:Aromatase Inhibitors; D002843:Chromatin; D004791:Enzyme Inhibitors; D018398:Homeodomain Proteins; C515057:NR5A1 protein, human; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D012313:RNA; D000077209:Decitabine; D008156:Luciferases; D001141:Aromatase; D001374:Azacitidine