Expression of Apoptosis Associated Proteins (Fas, Bcl2) in Oral Lichen Planus

Oral lichen planus (OLP) is a lymphocyte-mediated immunologic disorder in which basal keratinocytes appear to be the target of T-lymphocytes، and after “Apoptosis” phenomenon، it leads to hydropic degeneration of basal cells. Several proteins have been introduced in this process that may have major role in beginning and progression of apoptosis. The purpose of this study was to evaluate the immunohistochemical expression of two important pro-apoptotic (Fas) and anti-apoptotic (Bcl2) proteins in oral lichen planus and furthermore to evaluate the role of them in developing process of the lesion. In this cross sectional study، the paraffin embedded tissue sections of 12 OLP specimens (9 buccal mucosa and 3 gingival mucosa) and 12 non-lesional specimens (8 irritation fibroma and 4 normal gingival mucosa)، from archive of Oral and Maxillofacial Pathology Department of Dental School of Shahid Beheshti University of Medical Sciences were immunohistochemically stained using anti-Bcl2 and anti-Fas antibodies. The staining was eventually evaluated within epithelium and subepithelial connective tissue in each specimen. The intensity of staining was graded as weak (+)، moderate (++) and high (+++). The results were statistically analyzed to determine any probably significant relationship. The immunohistochemical expression of Fas between lesional and non-lesional groups in epithelial region was not significant (50% weak in both of them). No significant difference was also observed in expression of Fas in subepithelial region (83. 3% weak and moderate versus 90. 9% weak and moderate). The expression of Bcl2 showed no significant difference between two groups in epithelial region (100% weak versus 66. 7% weak). Also a significant difference of subepithelial expression of Bcl2 was noted between two groups (91. 7% moderate in lesional specimens versus 66. 7% in non-lesional ones (p=0. 01). The present study suggests that Bcl2 and Fas proteins probably may have no significant role in apoptosis in OLP and it is recommended to evaluate the other interfering proteins in this process.