To clarify the possible role of apoptosis in odontogenic epithelium, apoptosis-related factors and apoptotic cells were examined by immunohistochemistry and an in situ DNA nick end-labelling method. Expression of bcl-2 protein was detected in both normal and neoplastic odontogenic epithelium, whereas expression of p53 protein was detected only in neoplastic but not in normal odontogenic epithelium. The prevalence of cases positive for Lewis(y) antigen in ameloblastomas was significantly lower than in enamel organs. Correlation between these factors and apoptotic cells presented by an in situ DNA nick end-labelling method was not clear. The number of apoptotic cells in ameloblastomas was significantly greater than in normal odontogenic epithelium, and apoptotic reactions in the granular cell type ameloblastoma tended to be more frequently detected than in other types of ameloblastomas. These results suggested that apoptotic cell death might play an important role in oncogenesis and/or tissue differentiation in odontogenic epithelium.
Ameloblastoma Apoptosis