title: Antiproliferative and apoptotic effects of norethisterone on endometriotic stromal cells in vitro.
abstract: OBJECTIVE
  Low-dose estrogen-progestin (LEP) agents are often used for relieving endometriosis-associated chronic pelvic pain, but a direct effect of LEP on endometriotic lesions remains to be demonstrated. The objective of this study is to investigate the antiproliferative and apoptotic effects of the synthetic progestin norethisterone (NET) against human endometriotic stromal cells (ESCs).
  
  
  METHODS
  Ovarian endometrioma specimens were obtained at laparoscopy from 19 patients with endometriosis, and ESCs were isolated. The antiproliferative effect of compounds against cultured ESCs was evaluated by measuring the inhibition of [(3)H]thymidine incorporation. The ability of compounds to induce apoptosis in the cultured cells was evaluated by the measurement of caspase 3/7 activity and by nuclear staining. The cytotoxicity of compounds was evaluated by measuring the leakage of lactate dehydrogenase (LDH) into the supernatant of the cell culture.
  
  
  RESULTS
  NET and progesterone (P4) at concentrations of greater than 10nM significantly inhibited [(3)H]thymidine incorporation in a dose-dependent manner. Co-treatment with 17β-estradiol at 0.1 ng/mL did not affect the inhibition of [(3)H]thymidine incorporation by NET. At concentrations greater than 100 nM, NET significantly increased caspase 3/7 activity and the numbers of apoptotic cells, whereas P4 did not. Treatment of ESCs for 24h with NET or P4 at concentrations of up to 1000 nM did not cause LDH leakage.
  
  
  CONCLUSIONS
  NET inhibits the proliferation of ESCs and induces their apoptosis. These results suggest a possible direct effect of NET on endometriotic lesions in patients with endometriosis.
authors.affiliation: Discovery Research Laboratories, Nippon Shinyaku Co., Ltd., 14, Nishinosho-monguchi-cho, Kisshoin, Minami-ku, Kyoto 601-8550, Japan. t.minami@po.nippon-shinyaku.co.jp
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Minami
authors.forename: Keiji
authors.initials: K
authors.lastname: Kosugi
authors.forename: Izumi
authors.initials: I
authors.lastname: Suganuma
authors.forename: Kaoruko
authors.initials: K
authors.lastname: Yamanaka
authors.forename: Izumi
authors.initials: I
authors.lastname: Kusuki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Oyama
authors.forename: Jo
authors.initials: J
authors.lastname: Kitawaki
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003280:Contraceptives, Oral, Synthetic / Q000494:pharmacology / Q000627:therapeutic use*; D004353:Drug Evaluation, Preclinical; D004715:Endometriosis / Q000188:drug therapy*; D004717:Endometrium / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D005260:Female; D006801:Humans; D009640:Norethindrone / Q000494:pharmacology / Q000627:therapeutic use*; D011374:Progesterone; D017154:Stromal Cells / Q000187:drug effects; D018675:Toxicity Tests; D055815:Young Adult
chemical_list: D003280:Contraceptives, Oral, Synthetic; D011374:Progesterone; D053148:Caspase 3; D053179:Caspase 7; D009640:Norethindrone