Telomeric lengths and telomerase activity in liposarcomas

To assess the role of telomerase in the development of liposarcomas, we mea sured telomerase activity in 36 malignant and seven benign lipomatous neopl asias from 34 patients. A sensitive polymerase chain reaction-based telomer ase assay (the telomeric repeat amplification protocol) was applied. Shorte ning or elongation of telomeric repeat fragment lengths, as measured by usi ng hybridization with a telomere-specific oligonucleotide probe, was correl ated with the presence of telomerase activity. The latter was demonstrable in 69% of malignant tumors. Benign tumors can be distinguished from maligna nt neoplasias on the basis of telomerase activity. However, telomerase expr ession seems to be characteristic of poorly differentiated liposarcomas. My xoid/round cell liposarcomas exhibited a higher telomerase activity level t han the classical low-grade variants. Telomerase activity was not correlate d with age at the time of diagnosis or with sex. In most cases, telomerase- positive tumors showed higher proliferation indices than did neoplasias lac king telomerase. All eight recurrences expressed telomerase activity, refle cting a close association of telomerase with the biological behavior of lip osarcomas. Our findings suggest that telomerase may play a key role in the establishment and progression of malignant lipomatous tumors. Mol. Carcinog . 24:144-151, 1999. (C) 1999 Wiley-Liss, Inc.