title: Immunohistochemical expression of protein 53, murine double minute 2, B-cell lymphoma 2, and proliferating cell nuclear antigen in odontogenic cysts and keratocystic odontogenic tumor.
abstract: BACKGROUND
  Even though odontogenic cysts share a similar histogenesis, they show different growth and differentiation profile due to differences in the proliferative cellular activity.
  
  
  OBJECTIVE
  We perform an immunohistochemical assessment of protein 53 (p53), proliferating cell nuclear antigen (PCNA), B-cell lymphoma 2 (bcl-2), and murine double minute 2 (MDM2) expression in odontogenic cysts and keratocystic odontogenic tumor analyzing their correlation with the biological behavior of these lesions.
  
  
  METHODS
  By the streptavidin-biotin-peroxidase method with antibodies against p53, PCNA, bcl-2, and MDM2 proteins, 11 radicular cysts, 11 dentigerous cysts, and 11 keratocystic odontogenic tumor were analyzed. The non-parametric Mann-Whitney U-test and Kruskall-Wallis test (P ≤ 0.05) were used to analyze the data.
  
  
  RESULTS
  Immunopositivity for PCNA was observed in all cases appraised, predominantly in the suprabasal layer of keratocystic odontogenic tumor epithelial lining (SD ± 19.44), but no significant differences were found among the groups of lesions. Bcl-2 immunoexpression was observed especially in the basal layer of keratocystic odontogenic tumor. PCNA LI was significantly higher than bcl-2 LI in keratocystic odontogenic tumor. MDM2 and p53 immunoexpression were not detected in the lesions studied. Among the evaluated lesions, the keratocystic odontogenic tumor showed different immunoexpression of the proliferation and apoptosis markers.
  
  
  CONCLUSIONS
  The results of this study suggest that the keratocystic odontogenic tumor presents distinct biological behavior of the odontogenic cysts, as for the processes of proliferation, apoptosis, and differentiation, reinforcing the information in favor of the neoplastic nature of this lesion.
authors.affiliation: Professor of Oral Pathology, Post Graduation Program in Oral Pathology, Rio Grande do Norte Federal University - UFRN, Natal/RN, Brazil.
authors.forename: Hebel Cavalcanti
authors.initials: HC
authors.lastname: Galvão
authors.forename: Manuel Antonio
authors.initials: MA
authors.lastname: Gordón-Núñez
authors.forename: Rivadavio Fernandes Batista
authors.initials: RF
authors.lastname: de Amorim
authors.forename: Roseana de Almeida
authors.initials: Rde A
authors.lastname: Freitas
authors.forename: Lelia Batista
authors.initials: LB
authors.lastname: de Souza
mesh_terms: D017209:Apoptosis; D002454:Cell Differentiation; D049109:Cell Proliferation; D006801:Humans; D007124:Immunoenzyme Techniques; D009807:Odontogenic Cysts / Q000378:metabolism* / Q000473:pathology; D009808:Odontogenic Tumors / Q000378:metabolism* / Q000473:pathology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051736:Proto-Oncogene Proteins c-mdm2