Study On The Relationship Of The Activity Of Telomeraseand Its Relative Factors In Colorectal Cancer

(ABSTRACT)Objective: To investigate the roles of telomerase activity and its hTERT changes in the progression, metastasis as well as prognosis of colorectal cancer and the relationship with P53, PCNA, C-myc protein.Methods: PCR-TRAP-ELISA and Immunohistochemistry was used to detect the telomerase activity, hTERT changes and the expression of P53, PCNA and C-myc protein in 30 colorectal cancer tissues, paracancerous tissues, normal colorectal tissues, local lymphatic nodes and 20 adenomatous polyp respectively.Results: (1)The expression of telomerase activity was 83.33%, 13.33%, 3.33%, 10.00% in colorectal cancer tissues, paracancerous tissues, normal colorectal tissues and adenomatous polyp tissues, respectively. The expression of telomerase activity in colorectal cancer tissues was significantly higher than that in others tissues (P<0.05). (2)The expression of telomerase activity showed higher frequency in colorectal cancer with positive lymph nodes, compared to those with negative lymph nodes. (3)The positive rates of PCNA, C-myc and P53 were higher in colorectal cancer than other tissues. (4) The positive expression rates of telomerase activity in colorectal cancer tissues was correlated with C-myc and PCNA protein, but not to P53. (5)The positive rate of telomerase activity in colorectal cancer tissues detected by PCR-TRAP-ELISA and immunohistochemistry was 83.33% and 76.67% (P>0.05).Conclusions: (1)The expression of telomerase activity is closely related with colorectal cancer progression, invasiveness and metastasis, and the determination of telomerase activity could be useful in assessing malignant degree and lymphnode metastasis and in predicting prognosis of colorectal cancer. (2)The expressions of the activity of telomerase and the protein of hTERT were identical. (3) The origination of colorectal cancer was the results of many activated oncogenes and many inactivated tumor suppressor genes acted on each other. (4) The over expression of PCNA and C-myc protein may be relative to telomerase activity. P53 may be another independent factor in adjust the process of colorectal cancer.