[Expression and significance of HIF-1alpha and iNOS in human middle ear cholesteatoma epithelium].

OBJECTIVE

To investigate the expression of Hypoxia inducible factor-1alpha (HIF-1alpha) 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

Immunohistochemical SP method was used to examine the expression of HIF-1alpha and iNOS protein in 21 middle ear cholesteatoma specimens and 11 samples of normal external ear canal skin.

RESULTS

In the 21 middle ear cholesteatoma, in epithelium tissue samples and 11 external ear channel's normal skin specimens, the expression index of HIF-1alpha was 52.49 +/- 13.80, 0.60 +/- 0.49, and that of iNOS was 92.05 +/- 27.84, 1.15 +/- 0.84 respectively. The HIF-1alpha and iNOS expression index of cholesteatoma epithelium was significantly higher than that of external ear channel's normal skin (P < 0.01). Moreover in the cholesteatoma epithelium, linear correlation analysis showed that iNOS protein was positively correlated with HIF-1alpha protein expression (r = 0.536, P < 0.05).

CONCLUSIONS

High density of HIF-1alpha and iNOS are found in the epithelium of cholesteatoma; Hypoxia and its relative factors HIF-1alpha,iNOS may play an important role in the formation and development of cholesteatoma.