title: Patterns of p21(waf1/cip1) expression in non-papillomatous nasal mucosa, endophytic sinonasal papillomas, and associated carcinomas.
abstract: OBJECTIVE
  To clarify p21(waf1/cip1) expression in sinonasal lesions.
  
  
  METHODS
  Archived surgical specimens from 38 patients were investigated by means of immunohistochemistry. p21(waf1/cip1) staining was evaluated in the different layers of the epithelium. In addition, human papillomavirus (HPV) infection and p53 protein overexpression were assessed and correlated with p21(waf1/cip1) expression.
  
  
  RESULTS
  p21(waf1/cip1) staining was negative in non-papillomatous nasal mucosa. HPV infection and p53 protein overexpression were not seen. Sixteen of 20 inverted papillomas showed p21(waf1/cip1) expression. HPV infection was found in 16 cases and p53 protein overexpression was present in 13 specimens. Expression of p21(waf1/cip1) was restricted to surface cells in five cases, but involved basal/parabasal cells in 11 specimens. Immunoreactivity for p21(waf1/cip1) in basal/parabasal cells colocalised with p53 protein overexpression. Enhanced expression rates for p21(waf1/cip1) were seen in transitional and squamous epithelium compared with columnar epithelium. p21(waf1/cip1) expression involved only surface cells in cylindrical cell papillomas. HPV infection and p53 protein overexpression were detected in all specimens. One of five squamous cell carcinomas showed p21(waf1/cip1) expression. HPV infection was seen in two cases, and all carcinomas showed p53 protein overexpression.
  
  
  CONCLUSIONS
  Expression of p21(waf1/cip1) is associated with terminal differentiation in surface cells in inverted papillomas and cylindrical cell papillomas, but not in non-papillomatous nasal mucosa. Overexpression of p53 protein colocalises with p21(waf1/cip1) expression in basal/parabasal cells in inverted papillomas but not in cylindrical cell papillomas. Expression of p21(waf1/cip1) in squamous cell carcinomas involves a subset of tumours with p53 protein overexpression.
authors.affiliation: Department of Pathology, Military Hospital Ulm, D-89081 Ulm/Donau, Germany.
authors.forename: M J
authors.initials: MJ
authors.lastname: Schwerer
authors.forename: A
authors.initials: A
authors.lastname: Sailer
authors.forename: K
authors.initials: K
authors.lastname: Kraft
authors.forename: K
authors.initials: K
authors.lastname: Baczako
authors.forename: H
authors.initials: H
authors.lastname: Maier
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D002294:Carcinoma, Squamous Cell / Q000737:chemistry* / Q000821:virology; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000737:chemistry; D009363:Neoplasm Proteins / Q000032:analysis*; D009669:Nose Neoplasms / Q000737:chemistry* / Q000473:pathology / Q000821:virology; D010212:Papilloma / Q000737:chemistry* / Q000473:pathology / Q000821:virology; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000150:complications / Q000175:diagnosis; D010255:Paranasal Sinus Neoplasms / Q000737:chemistry* / Q000473:pathology / Q000821:virology; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
chemical_list: D015415:Biomarkers; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53