Dynamic alteration of telomerase expression and its diagnostic significance in liver or peripheral blood for hepatocellular carcinoma.
OBJECTIVE
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.


CONCLUSIONS
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.
Yao
Deng-Fu
DF
Research Center of Clinical Molecular Biology, Affiliated Hospital, Nantong University, Nantong 226001, Jiangsu Province, China. yaodf@ahnmc.com
Wu
Wei
W
Yao
Min
M
Qiu
Li-Wei
LW
Wu
Xin-Hua
XH
Su
Xiao-Qin
XQ
Zou
Li
L
Yao
Deng-Bing
DB
Meng
Xian-Yong
XY
D015073:2-Acetylaminofluorene / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000097:blood* / Q000175:diagnosis / Q000201:enzymology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008113:Liver Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D012313:RNA / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D016622:Silver Staining; D019098:Telomerase / Q000096:biosynthesis*
D012313:RNA; D015073:2-Acetylaminofluorene; D019098:Telomerase