Expression And Significance Of HIF-1α And INOS In Human Middle Ear Cholesteatoma Epithelium

Objectives The middle ear cholesteatoma is a common disease of otolaryngology characterized in pathology by the presence of hyperproliferative keratinizing squamous epithelium in the middle ear cavity and destruction of adjacent bone. The pathogenesis of cholesteatoma is not completely clarified today. This study is to investigate the expression of Hypoxia-inducible factor-1α(HIF-1α) and inducible Nitric Oxide Synthase (iNOS) in cholesteatoma and approach the possible role of them in the formation and development of the middle ear cholesteatoma.Methods We used the technology of immunohistochemical S-P method to examine the expression of HIF-1αand iNOS protein in 21 middle ear cholesteatoma specimens and 11 samples of normal external ear canal skin. The expression index of HIF-1αand that of iNOS were analyzed by SPSS 11.5 for Windows.Results In the 21 middle ear cholesteatoma epithelium tissue samples and 11 external ear cannel's normal skin specimens respectively, the expression index of HIF-1αwas 52.49士13.80, 0.60士0.49, and that of iNOS was 92.05士27.84, 1.15士0.84. The HIF-1αand iNOS expression index of cholesteatoma epithelium was significantly different from that of external ear cannel's normal skin in statistics( P<0.01). Moreover in the cholesteatoma epithelium, linear correlation analysis showed that iNOS protein was positively correlated with HIF-1αprotein( r=0.536,P < 0.05).Conclusions High density of HIF-1αand iNOS is found in the epithelium of cholesteatoma. HIF-1αinduces the expression of iNOS protein, and they promote cholesteatoma epithelium hyper proliferating together. All of this indicate hypoxia and its relative factors HIF-1α,iNOS play an important role in the formation and development of cholesteatoma.