title: Immunohistochemical assessment for Cdx2 expression in the Barrett metaplasia-dysplasia-adenocarcinoma sequence.
abstract: BACKGROUND
  Barrett oesophagus (BO) occurs as a consequence of prolonged gastro-oesophageal reflux and it may precede the development of oesophageal adenocarcinoma.
  
  
  OBJECTIVE
  The aim of this study was to accurately assess Cdx2 expression in the oesophageal metaplasia-dysplasia-adenocarcinoma sequence.
  
  
  METHODS
  The expression of the transcription factor Cdx2 in Barrett metaplasia, high-grade glandular dysplasia and adenocarcinoma was investigated using immunohistochemistry.
  
  
  RESULTS
  The results confirmed previous immunohistochemistry and PCR-based investigations, indicating that Cdx2 was expressed by intestinal metaplasia in the oesophagus. In addition, upregulation followed by linear downregulation of Cdx2 expression through the oesophageal metaplasia-dysplasia-adenocarcinoma sequence was demonstrated for the first time.
  
  
  CONCLUSIONS
  Such downregulation of Cdx2 expression could be in keeping with a role as a tumour suppressor gene, but a simpler explanation would be downregulation of a differentiation marker.
authors.affiliation: Department of Histopathology, Salford Royal NHS Foundation Trust, Salford, UK. stephen.hayes@srft.nhs.uk
authors.forename: Stephen
authors.initials: S
authors.lastname: Hayes
authors.forename: Sajad
authors.initials: S
authors.lastname: Ahmed
authors.forename: Peter
authors.initials: P
authors.lastname: Clark
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D001471:Barrett Esophagus / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D000071616:CDX2 Transcription Factor; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D009363:Neoplasm Proteins / Q000378:metabolism; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; D009363:Neoplasm Proteins