title: The renin-angiotensin system in Barrett's esophagus.
abstract: OBJECTIVE
  Barrett's esophagus (BE) is a risk factor for esophageal adenocarcinoma. In addition to its classical endocrine character known for hemodynamic regulation, the renin-angiotensin system (RAS) can be associated with inflammation, wound healing, and cancer. The aim of this study was to explore a potential expression of the RAS in BE, with or without the presence of dysplasia.
  
  
  METHODS
  Biopsy material was prepared for western blotting and immunohistochemistry. Non-BE patients (controls) were compared with BE patients regarding RAS in the squamous epithelium. In the columnar BE mucosa, RAS expression was studied in patients with and without dysplasia. Key components of the 'classical' RAS were assessed: the angiotensin-converting enzyme (ACE) and the angiotensin II subtype 1 and 2 receptors (AT1R and AT2R).
  
  
  RESULTS
  The presence of RAS factors was confirmed in the esophageal mucosa of both control and BE patients. ACE protein expression was 48% lower (p = 0.001) whereas AT1R was 45% higher (p = 0.039) in the squamous epithelium of BE patients compared to epithelia from non-BE controls. In the metaplastic intestinal-like epithelium, AT1R expression was 37% higher in BE patients with confirmed dysplasia than in patients without dysplasia (p = 0.009). Immunohistochemistry showed an altered distribution of RAS proteins in BE patients with dysplasia.
  
  
  CONCLUSIONS
  The differential RAS expression observed may prove to be useful as a biomarker or a pharmaceutical target.
authors.affiliation: a Department of Gastrosurgical Research and Education , Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital , Gothenburg , Sweden.
authors.forename: Svein Olav
authors.initials: SO
authors.lastname: Bratlie
authors.affiliation: a Department of Gastrosurgical Research and Education , Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital , Gothenburg , Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Edebo
authors.affiliation: a Department of Gastrosurgical Research and Education , Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital , Gothenburg , Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Casselbrant
authors.affiliation: a Department of Gastrosurgical Research and Education , Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital , Gothenburg , Sweden.
authors.forename: Herbert F
authors.initials: HF
authors.lastname: Helander
authors.affiliation: a Department of Gastrosurgical Research and Education , Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital , Gothenburg , Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Fändriks
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D016022:Case-Control Studies; D004724:Endoscopy; D004848:Epithelium / Q000378:metabolism / Q000473:pathology*; D004938:Esophageal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D004947:Esophagus / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000032:analysis*; D011945:Receptors, Angiotensin / Q000032:analysis*; D012084:Renin-Angiotensin System; D013548:Sweden
chemical_list: D015415:Biomarkers; D011945:Receptors, Angiotensin; C488034:ACE protein, human; D007703:Peptidyl-Dipeptidase A
keywords: Barrett’s esophagus; biomarkers; endoscopy; esophageal adenocarcinoma; renin–angiotensin receptor