A study on expression of tumor necrosis factor alpha in middle ear cholesteatoma and its effect on bone destruction / 临床耳鼻咽喉头颈外科杂志

ABSTRACT

Objective:To determine the expression and localization of tumor necrosis factor alpha(TNF-α) in human middle ear cholesteatoma and its effects on bone resorption.Method:The distribution of TNF-α in 18 cholesteatoma tissues and 8 normal external ear canal skin, facial skin and tympanic memebrane were studied immunohistochemically with paraffin-embedded sections.Result:TNF-α was localized in the epitheliun and connective tissue of cholesteatomas studied, particularly on basal and spinous cells and macrophages.The epithelium of normal external ear canal skin , facial skin and tympanic membrane was slightly stained.Conclusion:This study revealed significantly increased level of TNF-α in cholesteatoma tissues.TNF-α acts both directly,by causing bone erosion as an autocrine growth factor,and indirectly as an important mediator by stimulating the release of enzymes causing bone destruction.