Consistent decrease in telomere length in parathyroid tumors but alteration in telomerase activity limited to malignancies: preliminary report.

Telomerase is known to be activated and telomere length altered in various types of malignant and benign tumors, but whether this is also the case for parathyroid lesions has hitherto been unclear. We therefore investigated telomerase activity and telomere length in 3 parathyroid metastatic cancers, 6 adenomas, 2 cases of parathyroid hyperplasia, and 16 samples of normal parathyroid tissue. Telomerase activity, assayed by the telomeric repeat amplification protocol, was detected in all of the parathyroid cancers (100%), in none of the 8 parathyroid benign lesions, and in only 1 of the 16 normal parathyroid samples (8.3%). Telomere length, determined by the terminal restriction fragment assay, was reduced in the tumor tissues with a mean telomere length of 8.23 +/- 0.86 kbp compared with the 12.61 +/- 0.81 kbp for the 16 age-matched subjects (p = 0.002). The results indicate that telomerase activity and telomere length may reflect the biologic behavior of individual parathyroid lesions.