title: Oestrogen deficiency causes DNA damage in uterine leiomyoma cells: a possible mechanism for shrinkage of fibroids by GnRH agonists.
abstract: OBJECTIVE
  To examine whether gonadotrophin-releasing hormone agonist or oestradiol can directly affect DNA in leiomyoma cells.
  
  
  METHODS
  In vitro explant culture of leiomyoma cells.
  
  
  METHODS
  University research group.
  
  
  METHODS
  Leiomyoma cells were cultured from the specimens of four premenopausal women at myomectomy.
  
  
  METHODS
  The presence of gonadotrophin-releasing hormone receptor in leiomyoma cells was determined by reverse transcriptase-olymerase chain reaction. Leiomyoma cells were treated with gonadotrophin-releasing hormone agonist or cultured in different concentrations of oestrogen, progesterone or fetal calf serum for one, four or seven days.
  
  
  METHODS
  Cell number, expression of proliferating cell nuclear antigen, and DNA damage after one, four or seven days of treatment.
  
  
  RESULTS
  Gonadotrophin-releasing hormone receptor messenger ribonucleic acid was detected on cultured leiomyoma cells. Leiomyoma cell growth was not affected by the addition of gonadotrophin-releasing hormone agonist or progesterone, but increased with oestrogen or fetal calf serum supplementation. Overexpression of proliferating cell nuclear antigen was prevented in cultures added with oestrogen or fetal calf serum, but not related to gonadotrophin-releasing hormone agonist treatment. Significant decreases in DNA damage as indicated by decreased comet number were found in the leiomyoma cultures treated with oestrogen or fetal calf serum for four and seven days but not with gonadotrophin-releasing hormone agonist or progesterone. Furthermore, 5% fetal calf serum supplementation was more growth supporting and more significantly reduced the comet number than 250 pM 17 beta-oestradiol.
  
  
  CONCLUSIONS
  Cell growth, proliferating cell nuclear antigen expression and DNA damage are dependent on oestrogen or fetal calf serum, but independent of gonadotrophin-releasing hormone agonist or progesterone. Our findings suggest that gonadotrophin-releasing hormone agonist-induced leiomyoma shrinkage may be due in part to a mechanism involving DNA damage, and support the hypothesis that gonadotrophin-releasing hormone agonist exerts its action indirectly through oestrogen action on the tumour level.
authors.affiliation: Department of Obstetrics and Gynaecology, National Cheng Kung University Medical College, Taiwan.
authors.forename: Y M
authors.initials: YM
authors.lastname: Cheng
authors.forename: C Y
authors.initials: CY
authors.lastname: Chou
authors.forename: S C
authors.initials: SC
authors.lastname: Huang
authors.forename: H C
authors.initials: HC
authors.lastname: Lin
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D020552:Comet Assay / Q000379:methods; D004249:DNA Damage / Q000187:drug effects*; D004273:DNA, Neoplasm / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists*; D006801:Humans; D066298:In Vitro Techniques; D007889:Leiomyoma / Q000188:drug therapy* / Q000235:genetics; D016729:Leuprolide / Q000627:therapeutic use*; D011374:Progesterone / Q000494:pharmacology; D011966:Receptors, LHRH / Q000378:metabolism; D014594:Uterine Neoplasms / Q000188:drug therapy* / Q000235:genetics
chemical_list: D018931:Antineoplastic Agents, Hormonal; D004273:DNA, Neoplasm; D004967:Estrogens; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D016729:Leuprolide