[Physiopathology of beta and gamma catenin expression in the oral epithelium]

Catenins belong to a family of proteins that mediate the binding between intracytoplasmic domain of cadherins and cytoskeleton. Few data on distribution of beta and gamma catenins in non-neoplastic tissues are available from current literature. This study aims to evaluate distribution of beta and gamma catenins in oral epithelium.

Nine formalin-fixed and paraffin-embedded samples of oral epithelium were retrieved from files of Department of Oral Pathology of the University of Naples "Federico II". These samples were tested with anti-beta and anti-gamma monoclonal antibodies revealed by standard streptavidin-biotin-peroxidase technique. Sections have been evaluated by two observers by optical microscope using a 40X objective. The number of positive cells has been evaluated using a semi-quantitative method.

The results of this study show that beta and gamma catenins were mostly distributed in the upper two-thirds of oral epithelial thickness, except for keratinized areas which appear negative. Basal layer is positive except for the basal side of basal cells. Keratinized layers are negative for beta and gamma catenins.

In physiologic conditions staining pattern for beta and gamma catenins is almost exclusively membranous, sometimes cytoplasmic but never nuclear. This staining is well-represented even in conditions of chronic inflammation and leucoplakia.