title: Gonadotropin-releasing hormone and gonadotropin-releasing hormone receptor are expressed at tubal ectopic pregnancy implantation sites.
abstract: To investigate whether gonadotropin-releasing hormone (GnRH) and GnRH receptor (GnRHR) are expressed at tubal ectopic pregnancy sites, and to study the potential role of GnRH signaling in regulating immortalized human trophoblast cell viability.
  
  
  
  Immunohistochemical and experimental studies.
  
  
  
  Academic research laboratory.
  
  
  
  Fallopian tube implantation sites (n = 25) were collected from women with ectopic pregnancy. First-trimester human placenta biopsies (n = 5) were obtained from elective terminations of pregnancy.
  
  
  
  None.
  
  
  
  GnRH and GnRHR expression was examined by means of immunohistochemistry and histoscoring. Trophoblastic BeWo choriocarcinoma and immortalized extravillous trophoblast (HTR-8/SVneo) cell viability was examined by means of cell counting after incubation with GnRH and/or GnRH antagonist (Antide).
  
  
  
  GnRH and GnRHR immunoreactivity was detected in cytotrophoblast, syncytiotrophoblast, and extravillous trophoblast in all women with tubal pregnancy. GnRH immunoreactivity was higher and GnRHR immunoreactivity lower in syncytiotrophoblast compared with cytotrophoblast. GnRH and GnRHR immunoreactivity was detected in adjacent fallopian tube epithelium. Whereas neither GnRH nor Antide altered HTR-8/SVneo cell viability, treatment with GnRH significantly increased the overall cell viability of BeWo cells at 48 and 72 hours, and these effects were abolished by pretreatment with Antide.
  
  
  
  GnRH and GnRHR are expressed in trophoblast cell populations and fallopian tube epithelium at tubal ectopic pregnancy sites. GnRH increases BeWo cell viability, an effect mediated by the GnRHR. Further work is required to investigate the potential role of GnRH signaling in ectopic pregnancy.
authors.affiliation: Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Bo
authors.initials: B
authors.lastname: Peng
authors.affiliation: Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Klausen
authors.affiliation: MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Lisa
authors.initials: L
authors.lastname: Campbell
authors.affiliation: Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Peter C K
authors.initials: PC
authors.lastname: Leung
authors.affiliation: MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Horne
authors.affiliation: Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: mohamed.bedaiwy@cw.bc.ca.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Bedaiwy
mesh_terms: D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000502:physiology; D010064:Embryo Implantation / Q000502:physiology*; D005187:Fallopian Tubes / Q000378:metabolism / Q000473:pathology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis*; D006801:Humans; D011247:Pregnancy; D011274:Pregnancy, Tubal / Q000378:metabolism* / Q000473:pathology; D011966:Receptors, LHRH / Q000096:biosynthesis*; D014327:Trophoblasts / Q000378:metabolism / Q000473:pathology
chemical_list: C484844:GNRHR protein, human; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone
keywords: GnRH; GnRHR; ectopic pregnancy; fallopian tube; trophoblast