title: Comparative study of HER2, EGFR, p53 and PTEN expression in the human gastrointestinal tract during fetal period.
abstract: BACKGROUND
  HER2, EGFR, p53 and PTEN are important in organization of the germ layers, in embryonic development and morphogenesis, in the development and differentiation of certain organ systems and in embryonic morphogenesis. Our goal is the comparative examination of the expression of these markers in the digestive tract of 9-24-week-old fetuses.
  
  
  METHODS
  We studied using immunohistochemical techniques esophagus, stomach, small and large intestine tissue samples collected from 18 post mortem fetuses of 9-24 weeks.
  
  
  RESULTS
  HER2 and PTEN expression appears as early as the 9-12 weeks period in the digestive tract, but HER2 expression decreases in the 21-24 weeks period and then disappears. EGFR expression appears only during the 13-16 weeks period. The expression of p53 is strong until week 21, and then it is restricted to the deeper layers of the epithelium.
  
  
  CONCLUSIONS
  Our findings suggest that these markers have role also in the fetal period and complete the scarce data found in literature about the expression of the studied markers in the development of the digestive tract.
authors.affiliation: Department of Anatomy and Embryology, University of Medicine and Pharmacy of Tirgu Mures, Romania; papzsuzsa@yahoo.com.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Ghizdavăţ
authors.forename: Gergő
authors.initials: G
authors.lastname: Ráduly
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Pap
authors.forename: Lóránd
authors.initials: L
authors.lastname: Dénes
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Pávai
mesh_terms: D066246:ErbB Receptors / Q000378:metabolism*; D004947:Esophagus / Q000196:embryology / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000196:embryology* / Q000378:metabolism*; D006801:Humans; D008297:Male; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D011247:Pregnancy; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D013270:Stomach / Q000196:embryology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D066246:ErbB Receptors; D051059:PTEN Phosphohydrolase; D018719:Erb-b2 Receptor Tyrosine Kinases; D016159:Tumor Suppressor Protein p53; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C494929:PTEN protein, human