Abstract: The aim was to study the expression of telomerase activity in tissues of colorec tal carcinom a and to investigate its clinical value in prevention, diagnosis, treatment. A t otal of 50 human colorectal tissue specimens, comprising 40 carcinomas and 10 tu mor-adjacent normal tissue specimens were examined for telomerase activity by t elomeric repeated amplification protocol (TRAP) assay. In the 40 colorectal carc in oma specimens, 34 cases were detected positive expression of telomerase activity (85%), 10 specimens of tumor-adjacent normal tissue were negative. There was si gnificantly difference between the two groups (P< 0.05). There was no rel ationshi p between telomerase activity and the site of colorectal carcinoma, the level of cell differentiation, Dukes stage, metastasis of lymph nodes (P> 0.05). Th ere is common telomerase activity of colorectal carcinoma tissues. Telomerase ac tivity can become a gene marker of colorectal carcinoma tissues. Detecting the t elomerase activity of colorectal carcinoma tissues may help early discovery, ear ly diagnosis, early treatment. Inhibiting the telomerase activity may cure color ectal carcinoma. Inhibiting or destorying the process of telomerase activity may prevent the cause of colorectal carcinoma.

Key words: colorectal neoplasm, telomerase, telomeric repeat amplification protocol assay(TRAP)