Immunohistochemical analysis of p53 and p63 in selected odontogenic cysts and tumours.

Abstract

Background: It is a well-recognized fact that abnormal cell proliferation plays a crucial role in the development of odontogenic lesions. p53 is a tumour-suppressor gene which assists in cell cycle regulation and p63 is a homolog of p53 responsible for ectodermal differentiation and maintenance of stratified epithelial progenitor-cell. Analysing the tissue expression of p53 and p63 in odontogenic lesions may provide us with an insight into their potential role in the development of these lesions.

Objective: The objective is to study the expression of p53 and p63 in selected odontogenic lesions using immunohistochemistry.

Materials and methods: Formalin-fixed paraffin-embedded tissues of 15 ameloblastomas, 10 adenomatoid odontogenic tumours (AOT), 15 odontogenic keratocysts (OKCs), 10 dentigerous cysts (DCs) along with 10 cases of normal mucosa were retrieved from the departmental archives. These specimens were then subjected to immunohistochemical staining using p53 and p63 oncoproteins.

Results: p53 and p63 immune-expression showed mainly intranuclear localization. The mean positivity of p53 in ameloblastoma (59.45%) and OKC (26.38%) was significantly higher than AOT (6.77%) and DC (4%). In contrast, there was no significant difference in the positivity of p63 in between ameloblastoma (77.55%), AOT (69.50%), OKC (76.47%), and DC (50.69%).

Conclusion: p53 expression can be correlated with the clinical behaviour of the odontogenic lesions and it can be used as a prognostic marker in odontogenic cysts and tumours. In contrast, p63 expression does not corelate with the biological behaviour of odontogenic lesions.