Expression of annexin II in human middle ear cholesteatoma.

Annexin II has previously been discovered to have involvements in DNA replication and metabolism, bone resorption, and osteoclast formation. In our work, Western blotting and immunohistostaining studies revealed the presence of annexin II in human cholesteatoma tissue. With monoclonal mouse antiannexin II antibody, a 36,000 dalton protein (annexin II) was identified in the cholesteatoma protein extract. Immunoalkaline-phosphatase staining selectively localized annexin II to the keratinocytes in the basal and spinous layers of the cholesteatoma tissue. In normal human skin, annexin II is expressed mainly in the cytoplasmic membrane of its keratinocytes in the basal layer without significant staining in its nucleus. However, annexin II is expressed in both the cytoplasmic membrane and the nucleus of the keratinocytes in basal and spinous layers of human cholesteatomas. Our findings indicate a possible physiologic role of annexin II in keratinocyte cell hyperproliferation during development of human cholesteatoma.