Liver Cancer
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Aug 21, 2006; 12(31): 4966-4972
Published online Aug 21, 2006. doi: 10.3748/wjg.v12.i31.4966
Dynamic alteration of telomerase expression and its diagnostic significance in liver or peripheral blood for hepatocellular carcinoma
Deng-Fu Yao, Wei Wu, Min Yao, Li-Wei Qiu, Xin-Hua Wu, Xiao-Qin Su, Li Zou, Deng-Bing Yao, Xian-Yong Meng
Deng-Fu Yao, Wei Wu, Li-Wei Qiu, Xin-Hua Wu, Research Center of Clinical Molecular Biology, Affiliated Hospital, Nantong University, Nantong 226001, Jiangsu Province, China
Min Yao, Nanjing University, Nanjing 210008, Jiangsu Province, China
Xiao-Qin Su, Li Zou, Center of Oncology, Affiliated Hospital of Nantong University, Nantong 226001, Jiangsu Province, China
Deng-Bing Yao, Institute of Neurosciences, Nantong University, Nantong 226001, Jiangsu Province, China
Xian-Yong Meng, Department of Gastroenterology, Affiliated Hospital, Nantong University, Nantong 226001, Jiangsu Province, China
Author contributions: All authors contributed equally to the work.
Supported by grants-in-aid from the Key Project of Medical Science, No. RC2003100 and grants-in-aid from the project of Department of Health, No. H200523, Jiangsu Province, China
Correspondence to: Professor Deng-Fu Yao, MD, PhD, Re-search Center of Clinical Molecular Biology, Affiliated Hospital, Nantong University, 20 West Temple Road, Nantong, Jiangsu Province 226001, China. yaodf@ahnmc.com
Telephone: +86-513-83581539 Fax: +86-513-85052523
Received: August 31, 2005
Revised: May 13, 2006
Accepted: May 25, 2006
Published online: August 21, 2006
Abstract

AIM: To investigate the dynamic alteration of telomerase expression during development of hepatocellular carcinoma (HCC) and its diagnostic implications in liver tissues or peripheral blood mononuclear cells for HCC.

METHODS: Dynamic expressions of liver telomerase during malignant transformation of hepatocytes were observed in Sprague-Dawly (SD) rats fed with 0.05% of 2-fluoenyacetamide (2-FAA). Total RNA and telomerase were extracted from rat or human liver tissues. The telomerase activities in livers and in circulating blood were detected by a telomeric repeat amplification protocol-enzyme-linked immunosorbent assay (TRAP-ELISA), and its diagnostic value was investigated in patients with benign or malignant liver diseases.

RESULTS: The hepatoma model displayed the dynamic expression of hepatic telomerase during HCC development. The telomerase activities were consistent with liver total RNA levels (r = 0.83, P < 0.01) at the stages of degeneration, precancerosis, and cancerization of hepatocytes. In HCC patients, the telomerase levels in HCC tissues were significantly higher than in their adjacent non-cancerous tissues, but liver total RNA levels were lower in the former than in the latter. Although the circulating telomerase of HCC patients was abnormally expressed among patients with chronic liver diseases, the telomerase activity was a non-specific marker for HCC diagnosis, because the incidence was 15.7% in normal control, 25% in chronic hepatitis, 45.9% in liver cirrhosis, and 85.2% in HCC, respectively when absorbance value of telomerase activity was more than 0.2. If the value was over 0.6, the incidence was 60% in HCC group and 0% in any of the others (P < 0.01) except in two cases with liver cirrhosis. However, the combination of circulating telomerase with serum alpha-fetoprotein level could increase the positive rate and the accuracy (92.6%, 125 of 135) of HCC diagnosis.

CONCLUSION: The overexpression of telomerase is associated with HCC development, and its abnormality in liver tissues or in peripheral blood could be a useful marker for diagnosis and prognosis of HCC.

Keywords: Hepatocellular carcinoma; Telomerase; Peripheral blood mononuclear cells; Telomeric repeat amplification protocol