title: Absence of estrogen receptor-beta expression in metastatic ovarian cancer.
abstract: OBJECTIVE
  To evaluate the expression of estrogen receptor (ER)alpha and ERbeta mRNA and protein in normal ovarian tissue and primary and metastatic tumors.
  
  
  METHODS
  Estrogen receptor alpha and ERbeta expression was studied in normal ovarian biopsies (n = 9) and primary (n = 8) and metastatic ovarian epithelial cancers (n = 8). Ovarian tissue was collected from surgical samples. Estrogen receptor alpha and ERbeta mRNA expression was compared by coamplification of the mRNA of the ERs. Expression was confirmed at the protein level by Western blot analysis using antibodies specific for each receptor.
  
  
  RESULTS
  Among eight primary ovarian cancer samples, three had only ERalpha, two had only ERbeta, and three had both. All eight metastatic ovarian cancer tissues expressed only ERalpha mRNA and protein. Biopsies from normal ovaries had ERalpha and ERbeta mRNA and protein. Two of the ovarian epithelial cancer samples were paired and showed the same results.
  
  
  CONCLUSIONS
  We found varying amounts of ERalpha and ERbeta in normal ovaries, lower levels of ERbeta expression in ovarian epithelial cancer primary tumors, and only ERalpha in metastatic tumors. Our findings indicate that a fundamental difference might exist between primary and metastatic cells, which could be caused by intrinsic or extrinsic factors that regulate ER gene expression.
authors.affiliation: Departments of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: T
authors.initials: T
authors.lastname: Rutherford
authors.forename: W D
authors.initials: WD
authors.lastname: Brown
authors.forename: E
authors.initials: E
authors.lastname: Sapi
authors.forename: S
authors.initials: S
authors.lastname: Aschkenazi
authors.forename: A
authors.initials: A
authors.lastname: Muñoz
authors.forename: G
authors.initials: G
authors.lastname: Mor
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000473:pathology / Q000556:secondary*; D015153:Blotting, Western; D018283:Cystadenocarcinoma, Papillary / Q000235:genetics / Q000473:pathology / Q000556:secondary*; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000473:pathology; D010053:Ovary / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics*; D011960:Receptors, Estrogen / Q000235:genetics*
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D012333:RNA, Messenger; D011960:Receptors, Estrogen