title: Dienogest increases the progesterone receptor isoform B/A ratio in patients with ovarian endometriosis.
abstract: BACKGROUND
  The resistance of endometriotic tissue to progesterone can be explained by alterations in the distribution of progesterone receptor (PR) and estrogen receptor (ER) isoforms. The aims of this study were to examine the expressions of PR-A, PR-B, ERα and ERβ in endometrioma and assess whether these expressions are affected by dienogest or leuprolide acetate (LA) treatment.
  
  
  METHODS
  We enrolled 60 females, including 43 patients with endometriosis (14 who received no medical treatment, 13 who received dienogest and 16 who received LA before undergoing laparoscopic surgery) and 17 patients with leiomyoma. The expression levels of PR and ER isoforms in eutopic and ectopic endometrium were assayed with quantitative real-time PCR, and confirmed with immunohistochemistry.
  
  
  RESULTS
  A decreased PR-B/PR-A ratio and an increased ERβ/ERα ratio were demonstrated in ectopic endometrium derived from females with endometriosis compared with the ratios observed in eutopic endometrium obtained from females without endometriosis. Although LA treatment did not affect the PR-B/PR-A and ERβ/ERα ratios, dienogest treatment increased the PR-B/PR-A ratio and decreased the ERβ/ERα ratio in patients with endometriomas.
  
  
  CONCLUSIONS
  Dienogest may improve progesterone resistance in endometriotic tissue by increasing the relative expressions of PR-B and PR-A, and decreasing the relative expressions of ERβ and ERα.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki city, Osaka, 569-8686, Japan. gyn074@poh.osaka-med.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hayashi
authors.forename: Akiko
authors.initials: A
authors.lastname: Tanabe
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kawabe
authors.forename: Mika
authors.initials: M
authors.lastname: Hayashi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yuguchi
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Kiyoji
authors.initials: K
authors.lastname: Okuda
authors.forename: Masahide
authors.initials: M
authors.lastname: Ohmichi