J Korean Surg Soc.
2000 Mar;58(3):396-406.
Telomerase Activity of Normal Mucosa, Adenomatous Polyp and Cancer of the Colon
- Affiliations
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- 1Department of Surgery, St. Paul's Hospital, College of Medicine, The Catholic University of Korea.
Abstract
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PURPOSE: Progressive shortening of telomeres, specialized chromosomal structures that have a function
in chromosomal protection, positioning and replication, has been linked to cell senescence and aging.
Telomeres are usually replicated by telomerase, the activation of which is essential for cells to overcome
cellular senescence; and thus, indefinite proliferation/immortality and malignant progression are associated
with telomere activity. However, little is known about the telomerase activity in adenomatous polyp and
colorectal cancer. METHODS: To determine whether malignant progression depends on the activation of
telomerase or not, we analyzed the telomerase activity in the mucosa of normal colon, adenomatous polyp
and colorectal cancer by telomeric repeat amplification protocol (TRAP) assay and enzyme-linked
immunosorbent assay (ELISA). RESULTS: Except for one case in which there was severe inflammation,
telomerase activity was not detected in any case of histologically normal colonic mucosa. In contrast,
enzyme activity was detected in 58.3% (7/12), 75% (15/20) of adenomatous polyps and colorectal
carcinomas, respectively. Of these cases of adernomatous polyps, telomerase activity was positive in 40%
(2/5) of tubular type, 66.7% (4/6) of villotubular type and 100% (1/1) of villous type; however, the
difference in telomerase activity between tubular and villotubular types was not significant. Of these 20
cases of carcinomas, telomerase activity was positive in 100% (2/2) of well differentiated, 71.4% (10/14)
of moderately differentiated and 75% (3/4) of poorly differentiated histologies. Taking into consideration
the Dukes' classification, there was no significant difference in telomerase activity among stages A, B
and C, except for D. CONCLUSION: These results indicate that telomerase activation in colorectal cancer
may well correlate with malignant progression. The detection of telomerase activity may serve as a useful
auxiliary tool for the diagnosis of colorectal cancer; nevertheless, the histological type of
adenomatouspolyps, the histological differentiation and the stage of cancer may not correlate with
telomerase activity.