title: Expression of estrogen and progesterone receptors in endometrium and peritoneal endometriosis: an immunohistochemical and in situ hybridization study.
abstract: OBJECTIVE
  To clarify the role of ovarian steroids in the development and progression of endometriosis, estrogen receptors (ERs) and progesterone receptors (PRs) were localized by immunohistochemistry, and ER messenger RNA (mRNA) was detected by in situ hybridization in the uterine endometrium and in normal and altered pelvic peritoneum.
  
  
  METHODS
  Retrospective and prospective study.
  
  
  METHODS
  Nagasaki University School of Medicine, Nagasaki, Japan.
  
  
  METHODS
  A retrospective study of 61 formalin-fixed uterine endometria and normal and altered pelvic peritonea from patients suffering from various gynecologic diseases was conducted. In addition, in 22 fresh frozen tissue specimens, ER mRNA expression was evaluated prospectively.
  
  
  METHODS
  In formalin-fixed tissues, ER and PR were localized immunohistochemically. The results of immunohistochemical staining were scored from 0 to 4, depending on the signal intensity and frequency of positive cells. In fresh frozen specimens, ER mRNA expression was assessed by nonradioactive in situ hybridization using thymine-thymine dimerized oligonucleotide probes.
  
  
  RESULTS
  The highest score of ERs and PRs was observed in the epithelial and stromal cells of the normal uterine endometrium at the early proliferative phase of the menstrual cycle. The ER and PR scores declined throughout the secretory phase. In typical endometriotic lesions, the ER and PR scores were constantly high independent of the menstrual cycle. The expression pattern of ER mRNA was mostly in parallel with that of ERs. In typical endometriosis, ERs and PRs were found in both glandular epithelial cells and their surrounding stromal cells. Expression of ER mRNA was found in typical endometriotic peritonea and in pelvic peritoneum with columnar epithelial cells, but not in normal pelvic peritoneum (mesothelium). Estrogen receptors and PRs were negative in mesothelium, but were positive in the nuclei of fibroblasts in the connective tissue.
  
  
  CONCLUSIONS
  We demonstrated the expression of ERs, ER mRNA, and PRs in the columnar cells in pelvic peritonea and typical endometriosis, but not in normal mesothelium. These results suggest that endometriosis may originate from the columnar cells with ERs and PRs in the pelvic peritoneal lining.
authors.affiliation: Department of Obstetrics and Gynecology, Nagasaki University School of Medicine, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Fujishita
authors.forename: P K
authors.initials: PK
authors.lastname: Nakane
authors.forename: T
authors.initials: T
authors.lastname: Koji
authors.forename: H
authors.initials: H
authors.lastname: Masuzaki
authors.forename: R O
authors.initials: RO
authors.lastname: Chavez
authors.forename: T
authors.initials: T
authors.lastname: Yamabe
authors.forename: T
authors.initials: T
authors.lastname: Ishimaru
mesh_terms: D004715:Endometriosis / Q000378:metabolism*; D004717:Endometrium / Q000737:chemistry*; D004848:Epithelium / Q000737:chemistry; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008597:Menstrual Cycle; D010537:Peritoneum / Q000737:chemistry*; D011446:Prospective Studies; D012333:RNA, Messenger / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis* / Q000235:genetics; D011980:Receptors, Progesterone / Q000032:analysis* / Q000235:genetics; D012189:Retrospective Studies; D017154:Stromal Cells / Q000737:chemistry
chemical_list: D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone