QUANTIFICATION OF TELOMERASE ACTIVITY IN HUMAN LIVER-TISSUES BY FLUORESCENCE-BASED TRAP ANALYSIS

Normal human liver cells have a limited proliferactive capacity, but i mmortalized cells prevent the shortening of the end of chromosomes by the expression of telomerase, the enzyme that elongates telomeric DNA. In view of the wide variety of different methods of detecting telomer ase activity, a quantitative standard system is needed. Therefore, we constructed a quantitative system based on a TRAP-eze(TM) (ONCOR(R)) a nd the Fluorescence-based TRAP assay, and we quantified telomerase act ivity in normal liver tissues, livers with chronic liver disease, and livers with hepatocellular carcinoma (HCC). With this method, the aver age quantitative telomerase activity in chronic hepatitis tissues (n = 17) was 7.97 with a standard error of 6.07, in liver cirrhosis tissue s (n = 19) it was 10.82 with a standard error of 5.87, and in HCC tiss ues (n = 20) it was 46.87 with a standard error of 4.55. In all normal tissues (n = 3), telomerase activity was not detected. No difference between chronic hepatitis tissues and liver cirrhosis tissues was dete cted. But, the difference was highly significant (P < 0.001) between n ormal liver tissues and other liver tissues, between chronic hepatitis tissues and HCC tissues, and between liver cirrhosis tissues and HCC tissues. The possibility is great that chronic hepatitis tissues and l iver cirrhosis tissues become HCC when telomerase activity is high. Na mely, patients with high telomerase activity in chronic hepatitis and liver cirrhosis may be at the risk of developing HCC. This study showe d the assay of telomerase activity in chronic hepatitis tissues and li ver cirrhosis tissues could play a useful role in screening HCC. (C) 1 997 Elsevier Science Ireland Ltd.