Telomerase activity and cell proliferation index in cholesteatoma.
CONCLUSIONS
Telomerase activity was expressed in cholesteatomas, and cellular proliferation was significantly higher in cases where the telomerase activity was positive. Telomerase activity was also closely related with cellular proliferation in chronic hyperproliferating tissues such as cholesteatomas.


OBJECTIVE
Telomerase activity is detected in most malignant tumors and is also known to have a close relationship with cell proliferation. Cholesteatoma shows cellular hyperproliferation. We studied telomerase activity in cholesteatoma and its relationship with cellular proliferation and clinical findings.


METHODS
Cholesteatoma tissue was obtained from 40 patients during middle ear surgery. Telomerase activity was measured using a telomeric repeat amplification protocol method. As a cellular proliferation index, expression of Ki-67 was measured by means of immunohistochemical staining. Posterior auricular skin was used as a control. Telomerase activity was compared with Ki-67 expression. Clinical features such as hearing loss, the extension of cholesteatoma, the degree of bone destruction and the cause of cholesteatomas were compared with telomerase activity and the cellular proliferation index.


RESULTS
Telomerase activity was positive in 21/40 cholesteatomas (52.5%), but absent in the control group. The average Ki-67 labeling index in the cholesteatoma group was 32.84+/-10.13, higher than that in the control group (21.83+/-7.76) (p<0.05). The average Ki-67 labeling indices of the 21 telomerase activity-positive and 19 telomerase activity-negative cholesteatomas were 37.76+/-8.53 and 27.39+/-9.06, respectively. The Ki-67 labeling index was significantly higher in telomerase-positive cholesteatomas (p<0.05). The clinical features did not show a relationship with either telomerase activity or the cellular proliferation index.
Lee
Seung Hwan
SH
Department of Otolaryngology, College of Medicine, Hanyang University, Seoul, South Korea.
Jang
Young Ho
YH
Tae
Kyung
K
Park
Yong Wook
YW
Kang
Mi Jung
MJ
Kim
Kyung Rae
KR
Park
Chul Won
CW
D000293:Adolescent; D000328:Adult; D000368:Aged; D049109:Cell Proliferation; D002648:Child; D018424:Cholesteatoma, Middle Ear / Q000201:enzymology* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D019098:Telomerase / Q000032:analysis / Q000378:metabolism*
D019394:Ki-67 Antigen; D019098:Telomerase