[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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Li
Z
Z
Department of Otolaryngology, 163 Hospital of PLA, Changsha 410003.
Li
X
X
Liu
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D001862:Bone Resorption; D002648:Child; D018424:Cholesteatoma, Middle Ear / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000502:physiology
D014409:Tumor Necrosis Factor-alpha