Expression of PCNA In Experimental Cholesteatoma by Implanting tautologous Free Slim Graft in Mongolian Gerbil Middle Ear Cavity

Abstract

BACKGROUND AND OBJECTIVES: Cholesteatoma in the middle ear is characterized by the presence of a keratinizing epithelium which is believed to have hyperproliferative properties. Among the various approaches for evaluating proliferative activity, proliferating cell nuclear antigen (PCNA) has been recently induced as an antigenic marker of cellular proliferation. In this study, we investigated the hyperproliferative characteristic of implanted skin in Mongolian gerbil middle ear cavity by comparing its mitotic activity with that of the retroauricular skin. A secondary purpose was to provide the morphological basis for future animal studies concerning cholesteatoma pathogenesis. MATERIALS AND METHODS: Using immunohistochemical technique with anti-monoclonal antibody, we investigated PCNA expressions of the implanted free skin and normal retroauricular skin of Mongolian gerbils. RESULTS: Experimental cholesteatoma induced by implanting free skin graft showed an average PCNA labeling index of 0.47+/-0.07 and normal retroauricular skin revealed 0.14+/-0.05. The labeling index of experimental cholesteatoma was 3.47 times higher than that of normal retroauricular skin. CONCLUSION: The epithelium of experimental cholesteatoma induced by implanting free skin graft in gerbil middle ear cavity proliferates at a higher rate than its normal retroauricular skin, suggesting that this animal model can be used for future study of epithelial proliferation of cholesteatoma.