title: Differential expression of p53, p63 and p73 proteins in human buccal squamous-cell carcinomas.
abstract: Abnormalities in the p53 gene are regarded as the most consistent of the genetic abnormalities in oral squamous-cell carcinoma. Two new members of the p53 gene family, p73 and p63, have recently been identified, with the three sharing considerable sequence homology at the acidic N-terminal transactivation, central DNA-binding and C-terminal oligomerization domains, indicating possible functional and biological interactions. The differential expression of p73, p63 and p53 genes in human oral squamous-cell carcinoma does not yet appear to be completely understood, however. In this study, therefore, immunohistochemical analysis of protein expression was performed for 40 samples of well-differentiated human buccal squamous-cell carcinomas, with 10 specimens of normal buccal mucosa employed as controls. Differential expressions of p63, p73 and p53 proteins in the carcinoma samples were: p63+/p73+/p53 + (n = 28; 70%); p63+/p73+/p53- (n = 4; 10%); p63+/p73-/p53- (n = 8; 20%), respectively; and p63+/p73+/p53- for normal mucosa (n = 10; 100%). A significant correlation between p53, p63 and p73 immunoexpression was demonstrated for the buccal squamous-cell carcinoma samples (P < 0.0001; Fisher's exact test). Significance was not achieved for the correlation between p73 and p53 immunoexpression and clinicopathological parameters for buccal carcinomas (P > 0.05; Fisher's exact test). Our results indicate that both p73 and p63 may be involved in the development of human buccal squamous-cell carcinoma, perhaps in concert with p53.
authors.affiliation: Oral Pathology Department, School of Dentistry, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Y K
authors.initials: YK
authors.lastname: Chen
authors.forename: S S
authors.initials: SS
authors.lastname: Huse
authors.forename: L M
authors.initials: LM
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002294:Carcinoma, Squamous Cell / Q000737:chemistry* / Q000473:pathology; D004268:DNA-Binding Proteins / Q000032:analysis*; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000737:chemistry* / Q000473:pathology; D009687:Nuclear Proteins / Q000032:analysis*; D010750:Phosphoproteins / Q000032:analysis*; D011237:Predictive Value of Tests; D015534:Trans-Activators / Q000032:analysis*; D014157:Transcription Factors; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*; D025521:Tumor Suppressor Proteins
chemical_list: D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; C115051:TP63 protein, human; C000606460:TP73 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins