Prognostic value of human telomerase reverse transcriptase gene expression in oral carcinogenesis

Human telomerase reverse transcriptase (hTERT) gene expression in resected specimens of oral squamous cell carcinoma (OSCC) and their surrounding tissue, either apparently normal or clearly histologically dysplastic, was evaluated by both real-time RT-PCR and immunohisto-chemical protein analyses. The expression level of hTERT in oral dysplasia and in OSCC was markedly higher than in normal tissues. The correlation between hTERT expression in OSCC and clinico-pathological parameters or survival of OSCC patients was statistically analyzed. Our study demonstrates that there is no significant relationship between hTERT expression and classical clinico-pathological parameters. Interestingly, survival analysis showed both overexpressing cases and lower survival rate in the early stage of OSCC (p=0.03 for immunohistochemistry; p=0.04 for RT real-time PCR). The histological location of hTERT in these tumors has been discussed in the context of the cancer stem cell theory.