BCL-2 expression infollicular cyst and odontogenic keratocyst

ABSTRACT

Odontogenic keratocyst is a developmental odontogenic cyst with aggressive behavior and tendency to high recurrence. The cyst's epithelium shows more potential for growth than follicular cyst. On the other hand, BCL-2 is an anti apoptotic protein that can increase the longevity of epithelial cells. The purpose of this investigation was to compare the immunoreactivity in different layers and linings of both epitheliums of the follicular cyst and odontogenic keratacyst using BCL-2 anti-apoptotic marker. A retrospective descriptive study design was employed in order to evaluate 20 paraffin blacks of odontogenic keratocyst and 20 paraffin blocks of follicular cyst. The immunohistochemistry staining method was used together with BCL-2 marker [Anti BCL-2, Clone 124, Isotype IgG, Kappa, Dako, Denmark].The cytoplasms of epithelial cells were immunostained in different layers and all linings of the epithelium for both cysts, in 1000 epithelial cell counts. The collected data was analyzed using SPSS statistical software, and Roc Curve analysis as well as student T-test in order to prepare and report the results. Immunoreactivity with BCL-2 marker was 98.5 [ +/- 1.4%] in Basal layer, 12.1 [ +/- 3.2%] in intermediate, and null [0] in the surface layer of odontogenic keratocyst. Immunoreactivity with BCL-2 marker in basal layer was 2.1 [ +/- 1.9%] but the surface and intermediate layers did not immunostained with BCL-2 marker. The mean number of epithelial cells, positive for BCL-2, in all linings of follicular cyst was 0.7 [ +/- 0.63%] and in odontogenic keratocyst was 36.8 [ +/- 1.5%]. The mean immunoreactivity difference in layers of odontogenic keratocyst was statistically significant [P < 0.001]. However, the mean difference in immunoreactivity with BCL-2 marker was not significant [P > 0.05] in different layers of follicular cysts. Based on the results of this study, BCL-2 seams to be involved in pathogenesis of the odontogenic keratocyst. Likewise, the over-expression of BCL-2 marker in basal layer of odontogenic keratocyst was associated with increased recurrence and aggressive behavior of odontogenic keratocyst when compared with follicular cyst. Therefor, it can be suggested that the overexpression of BCL-2 in basal layer of odontogenic keratocyst can be considered as a useful marker to differentiate it from follicular cyst