title: p53 and MDM2 protein expression in actinic cheilitis.
abstract: Actinic cheilitis is a potentially malignant lip lesion caused by excessive and prolonged exposure to ultraviolet radiation, which can lead to histomorphological alterations indicative of abnormal cell differentiation. In this pathology, varying degrees of epithelial dysplasia may be found. There are few published studies regarding the p53 and MDM2 proteins in actinic cheilitis. Fifty-eight cases diagnosed with actinic cheilitis were histologically evaluated using Banóczy and Csiba (1976) parameters, and were subjected to immunohistochemical analysis using the streptavidin-biotin method in order to assess p53 and MDM2 protein expression. All studied cases expressed p53 proteins in basal and suprabasal layers. In the basal layer, the nuclei testing positive for p53 were stained intensely, while in the suprabasal layer, cells with slightly stained nuclei were predominant. All cases also tested positive for the MDM2 protein, but with varying degrees of nuclear expression and a predominance of slightly stained cells. A statistically significant correlation between the percentage of p53 and MDM2-positive cells was established, regardless of the degree of epithelial dysplasia. The expression of p53 and MDM2 proteins in actinic cheilitis can be an important indicator in lip carcinogenesis, regardless of the degree of epithelial dysplasia.
authors.affiliation: Department of Propaedeutics and Integrated Clinic, School of Dentistry, Federal University of Bahia, Salvador, BA, Brazil.
authors.forename: Maria da Conceição Andrade
authors.initials: Mda C
authors.lastname: de Freitas
authors.forename: Luciana Maria Pedreira
authors.initials: LM
authors.lastname: Ramalho
authors.forename: Flávia Caló Aquino
authors.initials: FC
authors.lastname: Xavier
authors.forename: André Luis Gomes
authors.initials: AL
authors.lastname: Moreira
authors.forename: Sílvia Regina Almeida
authors.initials: SR
authors.lastname: Reis
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002448:Cell Adhesion / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D002466:Cell Nucleolus / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D016764:Cell Polarity / Q000235:genetics; D002613:Cheilitis / Q000235:genetics / Q000473:pathology*; D002843:Chromatin / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D004847:Epithelial Cells / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D007633:Keratins; D008046:Lip / Q000473:pathology; D008938:Mitosis / Q000235:genetics; D051736:Proto-Oncogene Proteins c-mdm2 / Q000032:analysis*; D013472:Sunlight / Q000009:adverse effects; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D015415:Biomarkers; D002843:Chromatin; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D007633:Keratins; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2