Expression And Significance Of Proliferating Cell Nuclear Antigen And Heat Shock Protein 70 In Human Middle Ear Cholesteatoma

OBJECTIVE Cholesteatoma of the middle ear is an inflammatory disease characterized by the presence of hyperproliferative keratinizing squamous epithelium in the middle ear cavity and destruction of adjacent bone. The pathogenesis of cholesteatomas are not completely clarified. This study is to evaluate the possible role of Heat Shock Protein 70 (HSP70) in Cholesteatoma of the middle ear.METHODS The Cholesteatoma tissue samples were excised from 21 patients during surgery. Normal skin specimens collected from the external ear canal of 11 of the patients were used as controls. All the specimens were examined by immunohistochemical S-P method using monoclonal antibodies of HSP70 (Heat Shock Protein 70) and PCNA (Proliferating Cell Nuclear Antigen). The expression index of HSP70 and that of PCNA are analysed by SPSS (Statistical Package for the Social Science) using computer.RESULTS The distribution of HSP70 appeared to be localized in the nucleus of keratinocytes in the basal layer and the suprabasal cells ofthe epithelium of cholesteatoma,or and the cytoplasm. But the HSP70-positive cells only exist in the basal layer of the epidermis of the external ear canal skin feebly. Furthermore, the stain difference between the epithelium of cholesteatoma and the epidermis of the external ear canal skin is significant in statistics. The significant statistical difference of expression of PCNA-positive cells exists between each layer of cholesteatoma epithelium and normal external ear canal skin.The expression index of HSP70-positive cells in the epithelium of cholesteatoma was significantly correlated with that of the PCNA- positive cells .CONCLUSION PCNA represents a reliable marker for epithelial proliferation, showing that cholesteatoma epithelium proliferates at a higher rate than normal epidermis. High density of HSP70 in the epithelium of cholesteatoma suggests important roles for HSP70 in the clinical development of cholesteatoma. Cell proliferation is accompanied by production of HSP70. It seems that body may induce cell proliferation by increasing the synthesis of HSP70.