Clinical Significance of Expression of Epidermal Growth Factor, Epidermal Growth Factor Receptor, Transforming Growth Factor-alpha in Aural Cholesteatoma / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Aural cholesteatoma is characterized by hyperproliferation of keratinizing squamous epithelium in the middle ear cleft. Although the exact mechanism of bone destruction in aural cholesteatoma is still not clear, it was recently reported that a variety of cytokines, including epidermal growth factor (EGF), epidermal growth factor receptor (EGFR) and transforming growth factor-alpha (TGF-alpha) were over-expressed in aural cholesteatoma. The aim of this study is to demonstrate that there is over-expression of EGF, EGFR, and TGF-alpha in cholesteatoma and to evaluate the relationships between their expressions and clinical severity of the disease. MATERIALS AND METHODS: Expressions of EGF, EGFR, TGF-alpha were evaluated by immunohistochemical staining of cholesteatoma tissue and normal external auditory canal skin. The degree of expression were measured either by subjective observation and semi-quantitative image analysis. Both subjective scores and density scores were compared with clinical variables, such as the presence of preoperative otorrhea, complication, ossicular destruction, and the stage of cholesteatoma. RESULTS: The expression of EGF and TGF-alpha were more increased, particularly in the suprabasal layer of cholesteatoma epithelium than the normal skin. When the ossicular destruction and more extended cholesteatomas were present, the expressions if EGF and TGF-alpha were increased in the cholesteatoma tissues. CONCLUSION: The degree of expression of EGF and TGF-alpha in cholesteatoma may represent the clinical severity of the disease.