肿瘤坏死因子-α在中耳胆脂瘤的表达及其对邻近骨质的作用

目的 :探讨肿瘤坏死因子 - α(TNF- α)在中耳胆脂瘤中的表达及其对邻近骨质的作用。方法 :应用TNF- α单克隆抗体对 18例中耳胆脂瘤组织和 8例正常外耳道、面部皮肤和鼓膜进行免疫定位检测。结果 :TNF-α定位于胆脂瘤组织的上皮及上皮下结缔组织 ,较正常外耳道及鼓膜的染色明显增强。结论 :TNF- α在中耳胆脂瘤组织中有较高表达并通过两条途径引起骨质吸收 :1TNF- α作为自分泌调节因子引起破骨性骨吸收 ;2 TNF-α作为中间信使 ,激活炎性细胞释放一系列生物酶引起骨组织脱钙 ,骨基质、骨蛋白溶解 ,最终导致骨质吸收。

A study on expression of tumor necrosis factor alpha in middle ear cholesteatoma and its effect on bone destruction

OBJECTIVE: To determine the expression and localization of tumor necrosis factor alpha (TNF-alpha) in human middle ear cholesteatoma and its effects on bone resorption. METHOD: The distribution of TNF-alpha in 18 cholesteatoma tissues and 8 normal external ear canal skin, facial skin and tympanic membrane were studied immunohistochemically with paraffin-embedded sections. RESULT: TNF-alpha was localized in the epithelium 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-alpha in cholesteatoma tissues. TNF-alpha 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.