title: Molecular effects of genistein on male urethral development.
abstract: OBJECTIVE
  The increasing incidence of hypospadias is partly attributed to increased gestational exposure to endocrine disruptors. We investigated the effects of genistein, the primary phytoestrogen in soy, on the molecular program of male urethral development.
  
  
  METHODS
  Female mice were fed diets supplemented with genistein (500 mg/kg diet) or control diets before breeding and throughout gestation. Urethras from embryonic day 17.5 male fetuses were harvested, and RNA was prepared, amplified, labeled and hybridized on whole genome microarrays. Data were analyzed using packages from the R/Bioconductor project. Immunohistochemical analysis and immunoblotting were used to confirm the activity of MAPK and the presence of Ntrk1 and Ntrk2 during urethral development.
  
  
  RESULTS
  Gestational exposure to genistein altered the urethral expression of 277 genes (p <0.008). Among the most affected were hormonally regulated genes, including IGFBP-1, Kap and Rhox5. Differentially expressed genes were grouped into functional pathways of cell proliferation, adhesion, apoptosis and tube morphogenesis (p <0.0001), and were enriched for members of the MAPK (p <0.00001) and TGF-β (p <0.01) signaling cascades. Differentially expressed genes preferentially contained ELK1, Myc/Max, FOXO, HOX and ER control elements. The MAPK pathway was active, and its upstream genistein affected tyrosine kinase receptors Ntrk1 and Ntrk2 were present in the developing male urethra.
  
  
  CONCLUSIONS
  Gestational exposure to genistein contributes to hypospadias by altering pathways of tissue morphogenesis, cell proliferation and cell survival. In particular, genes in the MAPK and TGF-β signaling pathways and those controlled by FOXO, HOX and ER transcription factors are disrupted.
authors.affiliation: Department of Urology, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Ashley E
authors.initials: AE
authors.lastname: Ross
authors.forename: Luigi
authors.initials: L
authors.lastname: Marchionni
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Phillips
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Miller
authors.forename: Paula J
authors.initials: PJ
authors.lastname: Hurley
authors.forename: Brian W
authors.initials: BW
authors.lastname: Simons
authors.forename: Amirali H
authors.initials: AH
authors.lastname: Salmasi
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Schaeffer
authors.forename: John P
authors.initials: JP
authors.lastname: Gearhart
authors.forename: Edward M
authors.initials: EM
authors.lastname: Schaeffer
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D049109:Cell Proliferation; D002470:Cell Survival; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics; D005260:Female; D005333:Fetus / Q000187:drug effects; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000235:genetics; D019833:Genistein / Q000633:toxicity*; D018398:Homeodomain Proteins / Q000235:genetics; D007021:Hypospadias / Q000139:chemically induced* / Q000196:embryology* / Q000235:genetics; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics; D009363:Neoplasm Proteins / Q000235:genetics; D048789:Phytoestrogens / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000235:genetics; D014521:Urethra / Q000187:drug effects* / Q000196:embryology*
chemical_list: D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; C467200:Foxo1 protein, mouse; D018398:Homeodomain Proteins; C492047:Hoxa7 protein, mouse; D009363:Neoplasm Proteins; D048789:Phytoestrogens; D016212:Transforming Growth Factor beta; D019833:Genistein; D048049:Extracellular Signal-Regulated MAP Kinases; D020929:Mitogen-Activated Protein Kinase Kinases