[A study on the state of cell proliferation and apoptosis in human middle ear cholesteatoma]

To study the state of proliferation and apoptotic cell death in cholesteatoma.

20 cholesteatoma samples and 10 normal external ear canal skin samples were studied with immunohistochemical SABC technique and TUNEL technique.

Immunohistochemical analysis using a monoclonal antibody to proliferation cell nuclear antigen (PCNA) demonstrated the presence of proliferating cell in the basal cell layer of normal external ear canal skin, whereas in the cholesteatoma tissue samples larger numbers of proliferation cell nuclear antigen-positive cells were also observed in the prickle and granular cell layers. The PCNA labeling index and the mean optical density were (10.52 +/- 2.65)% and (0.1340 +/- 0.0363) in normal external ear canal skin samples and (36.91 +/- 22.77)% and (0.2427 +/- 0.0586) in cholesteatoma tissue samples. In cholesteatoma tissue samples and normal external ear canal skin samples, apoptotic cell were observed in the prickle and granular cell layers. The apoptotic indexers were (27.50 +/- 12.50)% in cholesteatoma tissue samples and (9.96 +/- 3.86)% in skin samples.

The results demonstrate the rates of apoptotic cell death and cell proliferation in cholesteatoma are higher than those in normal skin. Increased cell proliferation and cell death will contribute to increased keratous debris.