[Telomerase expression in colorectal tubular adenoma determined by immunohistochemical staining].

Background/aims: Telomeres are simple repeat elements located at each chromosome end of eukaryotic cells. The main function of telomeres is to cap the chromosome end and protect it from enzymatic attack. Telomerase that facilitates the synthesis of telomere has been detected in not only cancer but also precancerous lesion. In this study, we compared the telomerase expression between low grade and high grade colorectal tubular adenoma.

Methods: Among tissues from forty eight patients with colorectal tubular adenoma (23 low grade and 25 high grade colorectal dysplasia), telomerase expressions were evaluated by immunohistochemical staining.

Results: We classified 48 patients into two groups by the extent of nuclei staining pattern. High telomerase expression was a group which showed staining nucleus pattern above 50% in tubular adenoma. Low telomerase expression was a group which showed staining pattern nucleus below 50%. Twelve in 25 high grade colorectal dysplasia showed high telomerase expression (48%). Only one in 23 low grade colorectal dysplasia showed high telomerase expression (4%). Telomerase expression was much higher in the tissues from the patients with high grade than in those with low grade colorectal dysplasia (p<0.05).

Conclusions: Activation of telomerase may be related to the malignant potential in colorectal epithelial cells. Further studies are needed to define the role of telomerase in colorectal tumorigenesis.