Telomerase repeat amplification protocol (TRAP): A new molecular marker for parathyroid carcinoma

Telomerase results to be active in human germ, stem cells, several malignan t cell tumors and in immortalized cell lines. In order to investigate if mo lecular mechanisms other than Rb gene inactivation can be helpful to diagno se malignancy of parathyroid tumors, we decided to investigate the presence of active telomerase in homogenates from different pathological parathyroi d tissues (hyperplastic, adenomatous, carcinomatous, and normal) and primar y cell cultures. The TRAP assay was pet-formed to detect this activity in h istologically characterized normal, hyperplastic, adenomatous, and carcinom atous human parathyroid tissues, primary cell Lines, and one metastatic tis sue from parathyroid carcinoma. Only malignant parathyroid glands and the m etastatic tissue were TRAP positive. Our findings suggest that telomerase e xpression could represent an important molecular mechanism underlying the a cquisition and progression of an aggressive phenotype of epithelial parathy roid cells and it may help to predict their malignant potential. The TRAP a ssay is easy to perform and it could become an additional tool to be includ ed in the harmamentarium for the molecular diagnosis of parathyroid carcino ma. (C) 1999 Academic Press.