Telomerase activity and telomerase catalytic subunit in hepatocellular carcinoma

Telomerase activation has been found in most malignant tumors. Human telomerase reverse transcriptase is a catalytic subunit of human telomerase and a rate-limiting factor of the enzymatic activity of telomerase. The present study was designed to examine the usefulness of detecting human telomerase catalytic subunit mRNA and telomerase activity as a molecular diagnostic marker for human liver cancers.

Thirty-one specimens of hepatocellular carcinoma and corresponding adjacent tissues were analyzed for human telomerase reverse transcriptase expression by reverse transcription polymerase chain reaction and for telomerase activity by polymerase chain reaction-based telomeric repeat amplification protocol.

Human telomerase reverse transcriptase mRNA expression was observed in 97% of hepatocellular carcinoma tissues, in contrast none of the non-tumorous liver tissues did. Telomerase activity was detected in 94% of hepatocellular carcinoma and in only 16% of adjacent liver tissues. Human telomerase reverse transcriptase mRNA expression and telomerase activity were observed in all 3 grade I (well-differentiated) hepatocellular carcinoma. Significant correlations between human telomerase reverse transcriptase mRNA expression and hepatocellular carcinoma and also between telomerase activity and HCC were found (both p<0.001).

The results indicate that human telomerase catalytic subunit mRNA expression and telomerase activity might be associated with hepatocellular carcinogenesis and could be as markers for diagnosis of hepatocellular carcinoma.