Correlation of telomerase activity, clinical prognosis and therapy in oralcarcinogenesis

Telomerase activity is associated with most malignant tumors. To evaluate t he role of telomerase reactivation as a diagnostic and prognostic market in oral carcinogenesis activity was investigated in mortal and immortal cell lines in eight oral leukoplakias (OL) and 46 oral squamous cell carcinomas (OSCC). Activity was also investigated in 13 histopathologically unaffected mucosas from distant sites or tumor-free margins of the same patients usin g a modified, highly sensitive, nonradioactive telomeric repeat amplificati on protocol (TRAP). This was correlated with histopathological stages and t he clinical course of the disease. 50% of OL and 46% of OSCC showed activit y. One patient with positive high dysplastic OL developed an OSCC 11 month later. One of three specimens of adjacent tissue presented activity and a r ecurrence occurred after 6 months. Out of IO tissues of distal normal mucos a, 2 demonstrated activity which could also be proved in the corresponding tumor. Detection of telomerase reactivation may be a novel method for early detection of immortalised cell clones and malignant cells in histopatholog ically normal oral squamous epithelium.