Evaluation of telomerase activity in cutaneous melanocytic proliferations.

Telomerase is an enzyme which synthesizes the telomeres, TTAGGG repeats at the end of vertebrate chromosomes. Its activity is suppressed in the majority of somatic cells, whereas it is detectable in most tumor cell lines and human cancers. Telomerase activity has been evaluated in many tumors for diagnostic purposes, and an increase thereof has been found with tumor progression. In our study we used anonisotopic polymerase chain reaction (PCR)-based TRAP (telomeric repeat amplification protocol) method to quantify the level of telomerase activity in a series of cutaneous melanocytic lesions. Thirty-three benign nevi, 8 dysplastic nevi, 38 malignant melanomas, and 4 melanoma metastases were analyzed. Mean relative telomerase activity was low in benign nevi (3.5+/-2.9), and significantly increased in dysplastic nevi (13.1+/-6.8), malignant melanomas (49.8+/-29.6), and metastases (121.2+/-11.2). In addition to the evaluation of telomerase activity as a possible diagnostic tool, its increase with tumor progression also suggest a prognostic role in cutaneous melanoma.