[The expressions and correlations of RAR-beta receptors and galectin-8 in human middle ear cholesteatoma].

OBJECTIVE

To explore the expression and correlation of RAR-beta receptor and galectin-8 in acquired middle ear cholesteatoma, and to evaluate their roles in the formation of middle ear cholesteatoma.

METHOD

Tissue specimens from 42 cases of acquired middle ear cholesteatoma and 18 cases of external ear skin were examined by immunohistochemical SABC method for RAR-beta receptors and galectin-8, also by Western Blot for these two factors.

RESULT

All 42 samples of cholesteatoma showed a stronger expression of RAR-beta receptor than the external ear skin. The mean optical absorbency density of RAR-beta receptor in the two types of tissues were 0.2734 +/- 0.0022, respectively, with statistically significant difference between them. RAR-beta receptor expressed in the cytoplasm and membrane of the full epithelial tissue, and not remarkably expressed in the external ear skin cells. Beside the basal cell layers, keratinocytes of the suprabasal cell layers were found to contain galectin-8 expression. The mean optical density of galectin-8 in the two types of tissues were 0.2826 +/- 0.0016 and also with statistically significant difference between them. Furthmore, the level of RAR-beta expression correlated highly (P < 0.01) with the level of galectin-8 expression.

CONCLUSION

An undifferentiated population of keratinocytes may lead to the formation of cholesteatoma, and a relation may exist between retinoid activity and galectins.