Immunohistochemical study of ki-67 and bcl-2 expression in some odontogenic cystic lesions with different clinical behaviors

Cystic lesions with odontogenic epithelial origin and similar clinicoradiographic appearance, show different clinical behaviors.
To compare some factors related to cell proliferation and escape from apoptosis in epithelium covering two groups of odontogenic cystic lesions with different clinical behaviors.
In this cross-sectional study 11 paraffin-embedded samples were selected of each lesions radicular cyst, dentigerous cyst, odontogenic keratocyst, and unicystic ameloblastoma. The sample underwent immunohistochemical staining for investigating the expression of ki-67 antigen and bcl-2 protein. Data analyzed with SPSS17 software and Kruskal–Wallis and chi-square statistical tests.
Findings: Most of ki-67 positive cells were observed in parabasal layer of odontogenic keratocyst [35.50±26.29%; P=0.001]. The average of ki-67-LI was more in parabasal layer of aggressive group (26.80±37.79%) compared to non-aggressive group (4.04±3.38%), was not being statistically significant. The highest average of bcl-2-LI was 95±6.70% in basal layer of odontogenic keratocyst (P=0.001). In all layers, the average of bcl-2-LI was more in aggressive lesions compared to non-aggressive ones and the highest amount was found in basal layer (72.45±3.94×10%) which was statistically significant (P=0.001).
According to the results of this study, more expression of the markers related to escape from apoptosis in aggressive lesions group compared to non-aggressive group, suggests that escape from apoptosis had a more critical role in aggressive behavior of odontogenic cystic lesions.