[Expression of transforming growth factor-beta 1 matrix metalloproteinase-1 and its inhibitor in human middle ear cholesteatoma].

Objective: To investigate the expression of matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and transforming growth factor-beta 1 (TGF-beta 1) in human middle ear cholesteatoma.

Methods: Immunohistochemical staining was used to detect the expression of TGF-beta 1, MMP-1 and TIMP-1 in the cholesteatoma (41 cases) and the skin of external auditory meatus (15 cases).

Results: The percent of positive expression of TGF-beta 1, MMP-1 and TIMP-1 in cholesteatoma was 95.12%, 85.37% and 9.76%, respectively. There was significant difference of the expression of MMP-1 and TGF-beta 1 between cholesteatoma and external auditory meatus skin (P < 0.05). But there was no statistic significance for TIMP-1 (P > 0.05). There was correlation between the expression of TGF-beta 1 and MMP-1, but no correlation between TGF-beta 1 and TIMP-1.

Conclusion: The imbalance between the expression of MMP-1 and TIMP-1 in cholesteatoma may cause directly proteolytic activity involved in pathologic osteolytic mechanisms.