Overexpression of ErbB-2 protein in human middle ear cholesteatomas.
OBJECTIVE
The purpose of this study is to verify the hypothesis that ErbB-2 protein is overexpressed in human middle ear cholesteatomas and to elucidate the relationship between overexpression of ErbB-2 protein, cell proliferation, and apoptosis.


METHODS
Prospective review of 20 patients between 2001 and 2003 with middle ear cholesteatoma.


METHODS
Middle ear cholesteatoma matrix and retroauricular skin were immunostained with anti-ErbB-2, Ki-67, and single-stranded DNA (ssDNA) antibody. The distribution of immunoreactivity to these antibodies and labeling indices were compared between cholesteatoma and retroauricular skin.


RESULTS
In matrix of middle ear cholesteatoma, ErbB-2 and ssDNA were expressed in the keratinocytes of all layers and Ki-67 was expressed in the keratinocytes of the basal, lower spinous, and occasionally granular layer. In retroauricular skin, ErbB-2 and Ki-67 were expressed in the keratinocytes of the basal and occasionally lower spinous layer and ssDNA was expressed in the keratinocytes of all layers. Labeling indices against anti-ErbB-2, Ki-67, and ssDNA antibody were significantly greater in cholesteatoma as compared with retroauricular skin.


CONCLUSIONS
In cases of cholesteatoma, ErbB-2 protein was overexpressed and cell proliferation and apoptosis of keratinocytes were accelerated. ErbB-2 protein could modulate terminal differentiation and apoptosis in the keratinocytes of all layers in cholesteatoma matrix and cell proliferation in the keratinocytes of the basal and lower spinous layer in normal skin.
Sakamoto
Takashi
T
Department of Otorhinolaryngology, Mutual Aid Association for Tokyo Metropolitan Teachers and Officials, Sanraku Hospital, Tokyo, Japan. ta-saka@nifty.com
Kondo
Kenji
K
Yamasoba
Tatsuya
T
Suzuki
Mitsuya
M
Sugasawa
Masashi
M
Kaga
Kimitaka
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D018424:Cholesteatoma, Middle Ear / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018739:Oncogene Proteins v-erbB / Q000096:biosynthesis* / Q000235:genetics; D011446:Prospective Studies
D018739:Oncogene Proteins v-erbB