Miura N et al. (2005) Serum human telomerase reverse transcriptase messenger RNA as a novel tumor marker for hepatocellular carcinoma. Clin Cancer Res 11: 3205–3209

Telomeres are usually shortened during the cell cycle, which eventually leads to cell death. In cancer cells, however, telomere length can be maintained through reactivation of telomerase. The key protein subunit of the telomerase complex is the human telomerase reverse transcriptase (hTERT), which mediates nucleotide addition. In previous studies, hTERT messenger RNA (mRNA) was upregulated in hepatocellular carcinoma (HCC), and was superior to alpha fetoprotein (AFP) for the early detection of HCC patients whose AFP levels were low. Following on from this, Miura et al. carried out a trial in 64 HCC patients to compare hTERT mRNA with conventional tumor markers such as AFP, AFP-L3, and des-gamma-carboxy prothrombin, for the diagnosis of HCC.

The study showed that there was a significant correlation between hTERT mRNA in the HCC tissue and in the serum, which suggests that hTERT mRNA in serum is derived from HCC tissue. The study also showed that hTERT expression was related to tumor number, degree of tumor differentiation and intrahepatic metastasis; however, none of the conventional markers showed correlation to these factors. hTERT was also related to tumor size. Furthermore, unlike AFP, hTERT was able to distinguish HCC from noncancerous liver disease.

hTERT mRNA expression is a novel and available marker for HCC diagnosis and it is superior to other conventional markers. The authors conclude that a large-scale study might be required to confirm these results.