title: Clomiphene citrate versus letrozole: molecular analysis of the endometrium in women with polycystic ovary syndrome.
abstract: OBJECTIVE
  To compare the effect of clomiphene citrate (CC) and letrozole on endometrial receptivity in women with polycystic ovary syndrome (PCOS).
  
  
  METHODS
  A randomized controlled trial.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  Ten anovulatory women with PCOS and 5 fertile ovulatory women.
  
  
  METHODS
  Patients received 2.5 mg of letrozole on cycle days 3-7 (5 patients, 1 cycle) or 50 mg of CC on cycle days 5-9 (5 patients, 1 cycle).
  
  
  METHODS
  Serum estrogen (E) and progesterone (P) endometrial protein and messenger RNA (mRNA) expression of leukemia inhibitory factor (LIF), dickkhopf homolog 1 (DKK-1), fibroblast growth factor 22 (FGF-22), and endometrial mRNA expression of LIF/GP130 receptor (LIFR).
  
  
  RESULTS
  No statistically significant differences were observed between groups compared with fertile ovulatory women when serum E and P were examined, or between body mass index (BMI), and cycle day at time of biopsy. Letrozole increased mRNA expression of LIF, DKK1, LIFR, and FGF-22, whereas CC only increased endometrial mRNA expression of LIF. Letrozole mRNA expression directly translated into increased protein expression of like genes in the endometrium. The CC protein expression of DKK-1 was significantly decreased compared with controls.
  
  
  CONCLUSIONS
  Letrozole positively influences a number of markers of endometrial receptivity compared with CC.
authors.affiliation: Department of Obstetrics & Gynecology, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA. kwallace2@umc.edu
authors.forename: Kedra L
authors.initials: KL
authors.lastname: Wallace
authors.forename: Venessia
authors.initials: V
authors.lastname: Johnson
authors.forename: Victoria
authors.initials: V
authors.lastname: Sopelak
authors.forename: Randall
authors.initials: R
authors.lastname: Hines
mesh_terms: D000328:Adult; D002996:Clomiphene / Q000494:pharmacology / Q000627:therapeutic use*; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism*; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology / Q000627:therapeutic use; D005786:Gene Expression Regulation; D006801:Humans; D000077289:Letrozole; D053605:Leukemia Inhibitory Factor / Q000096:biosynthesis / Q000235:genetics; D009570:Nitriles / Q000494:pharmacology / Q000627:therapeutic use*; D011085:Polycystic Ovary Syndrome / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism*; D053606:Receptors, OSM-LIF / Q000096:biosynthesis / Q000235:genetics; D014230:Triazoles / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D005300:Fertility Agents, Female; D053605:Leukemia Inhibitory Factor; D009570:Nitriles; D053606:Receptors, OSM-LIF; D014230:Triazoles; D002996:Clomiphene; D000077289:Letrozole