Journal of Clinical Oncology, Vol 15, 1932-1937, Copyright © 1997 by American Society of Clinical Oncology
Differential expression of telomerase activity in human cervical cancer and cervical intraepithelial neoplasia lesions
CC Pao, CJ Tseng, CY Lin, FP Yang, JJ Hor, DS Yao and S Hsueh
Department of Biochemistry, Chang Gung College of Medicine and Technology, Taipei, Taiwan. ccpao@cguaplo.cgu.edu.tw
PURPOSE: Telomeres are tandem arrays of repeated DNA sequences located at
the ends of eukaryotic chromosomes, and are synthesized by the enzyme
telomerase. Loss of telomeric DNA may play an important role in the
development of human cancers. However, very little is known about the
status of telomerase during human cervical cancer development. PATIENTS AND
METHODS: Telomerase activity was measured by telomere repeat amplification
protocol (TRAP) assay in 24 cervical cancers, one carcinoma in situ (CIS),
and 20 cervical intraepithelial neoplasia (CIN) lesions. Adjacent nontumor
cervical tissue from the same 24 cervical cancer patients and normal
cervical tissues from 11 control individuals also were examined for the
presence of telomerase activity. RESULTS: Twenty two of the 24 (91.7%)
cervical cancer specimens and the single CIS tissue were strongly positive
for telomerase activity. Relatively weak but distinctive telomerase
activity also was detectable in one of four CIN-I (25%), two of eight
CIN-II (25%), and two of eight CIN-III (25%), respectively. However,
telomerase activity was not found in the 24 corresponding nontumor cervical
tissues from the same cervical cancer patients and the 11 normal cervical
tissues from control individuals. CONCLUSION: The majority of cervical
cancers contain strong telomerase activity. Significant proportions of
noncancerous CIN tissues also contain telomerase activity, although weaker
than that in cervical cancer. It seems that there is a progressive increase
of telomerase activity in association with an increased degree of cervical
malignancy. These results seem to suggest that the expression of telomerase
may play a crucial role in cervical cancer carcinogenesis.
