title: Localisation of COX-2 protein is different in breast ductal carcinoma and adjacent non-tumour ductal epithelium.
abstract: BACKGROUND
  A number of findings suggest that cyclooxygenase-2 (COX-2) is overexpressed in breast tumours. However, there is a lack of consensus in the literature regarding the pattern of expression of this protein in invasive breast ductal carcinoma and in the adjacent non-tumour ductal epithelium. This study compares the expression of COX-2 mRNA and protein in breast ductal carcinoma relative to non-tumour breast tissue.
  
  
  METHODS
  We analysed the expression of COX-2 mRNA by quantitative PCR, and COX-2 protein by immunohistochemistry in invasive ductal carcinoma as well as in non-tumour adjacent ductal epithelium from 34 breast biopsies diagnosed as being invasive ductal carcinoma. As control, we analysed expression of COX-2 protein by immunohistochemistry in surgically-resected benign breast lesions.
  
  
  RESULTS
  Our results show that COX-2 mRNA and protein are overexpressed in non-tumour ductal epithelium compared with invasive ductal carcinoma. However, the pattern of the protein expression is different in tumour and non-tumour tissue: COX-2 protein is expressed predominantly in the membrane of the non-tumour ductal epithelium (including in benign breast lesions) while, in invasive ductal carcinoma cells, it is localised in the cytoplasm.
  
  
  CONCLUSIONS
  The non-tumour ductal epithelium adjacent to invasive ductal carcinoma shows a higher COX-2 expression than does the invasive ductal carcinoma. However, the different localisation of the immunohistochemically-detected protein suggests a possible post-translational regulation of the protein.
authors.affiliation: Servicio de Oncología Médica, Unidad de Oncología Molecular, Hospital Universitario La Paz, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Cejas
authors.forename: M A
authors.initials: MA
authors.lastname: García-Cabezas
authors.forename: E
authors.initials: E
authors.lastname: Casado
authors.forename: J
authors.initials: J
authors.lastname: Barriuso
authors.forename: J A
authors.initials: JA
authors.lastname: Fresno
authors.forename: E
authors.initials: E
authors.lastname: Díaz
authors.forename: C
authors.initials: C
authors.lastname: Belda-Iniesta
authors.forename: J
authors.initials: J
authors.lastname: Castro
authors.forename: E
authors.initials: E
authors.lastname: Espinosa
authors.forename: P
authors.initials: P
authors.lastname: Zamora
authors.forename: J
authors.initials: J
authors.lastname: Feliu
authors.forename: A
authors.initials: A
authors.lastname: Redondo
authors.forename: D A
authors.initials: DA
authors.lastname: Hardisson
authors.forename: M
authors.initials: M
authors.lastname: González-Barón
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000378:metabolism* / Q000473:pathology; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger