Evaluating Bcl-2, Bax and C-erbB-2 levels in cholesteatoma in patients with chronic otitis media with cholesteatoma

In this study our goal to evaluate the expressions of bcl-2, bax and c-erbB-2 in primary acquired and secondary acquired cholesteatomas and accordingly to reveal the role of apoptosis in the pathogenesis of cholesteatoma and the role of the increased cellular proliferation.The study was conducted on 60 patients who were operated due to COM with and without cholesteatoma. The patients were divided into four groups. The samples collected in the external ear canal of the patients who were operated due to COM without cholesteatoma constituted group 1. The samples collected in the external ear canal of the patients in group 3 and 4 who were operated due to COM with cholesteatoma constituted group 2. The samples collected in cholesteatoma matrix of the patients who were operated due to COM with primary acquired cholesteatoma constituted group 3. The samples collected in cholesteatoma matrix of the patients who were operated due to COM with secondary acquired cholesteatoma constituted group 4. The rate of positive cells were semi-quantitatively classified into four groups. The groups were defined as the following: 0- no staining, + cell staining ( low degree staining: l-33%), ++ cell staining (medium degree staining: 34-66%), +++ cell staining (high degree staining: 67-100%)There was statistically no difference in staining the samples collected in external ear canal of the patients who were operated due to COM with and without cholesteatomas when the staining scores of bcl-2, bax and c-erbB-2 compared (p>0.05). There was statistically no difference between primary and secondary acquired cholesteatoma epithelium in terms of bcl-2, bax and c-erbB-2 expressions. In primary and secondary acquired cholesteatoma epithelium bcl-2 expression decreased, on the other hand, bax and c-erbB-2 expressions increased when it was compared to the patients who were operated due to Com with cholesteatoma, and it was statistically significant (p<0,05). It was shown that there were higher rates of apoptosis in primary and secondary acquired cholesteatoma epithelium when compared with the external ear canal.Bcl-2 expression decreased, but bax and c-erbB-2 expressions increased in acquired cholestetatoma ephitelium compared to external ear canal skin. We concluded that both cellular proliferation and the increase in apoptosis may play an important role in pathogenesis of cholestetaoma.Key Words: Cholesteatoma, apoptosis, proliferation, bcl-2, bax, c-erbB-2