TELOMERASE ACTIVITY IN HODGKINS-DISEASE

Telomere maintenance executed by the action of telomerase seems to be a prerequisite for immortalization, Telomerase is found in most cell l ines and malignant tumors. A telomerase-independent mechanism for telo mere maintenance in Hodgkin's disease has been proposed in the absence of detectable telomerase activity, In this study, telomerase activity was detected in 31 of 77 Hodgkin's disease samples and a strong corre lation between eosinophilia and absence of detectable telomerase activ ity was found, Purified eosinophils and specifically eosinophil-derive d neurotoxin and eosinophilic cationic protein, bath ribonucleases, we re found to degrade telomerase. Purified neutrophils also exhibited we ak telomerase degradative activity, Reanalysis of previously telomeras e-negative Hodgkin's disease samples with eosinophilia using ribonucle ase inhibitors resulted in the detection of telomerase activity. Ribon uclease-containing cells in vivo thus have a considerable impact on th e detectability of telomerase. In Hodgkin's disease samples without eo sinophilia, 24 of 27 exhibited telomerase activity at decreased levels compared with non-Hodgkin's lymphomas and at increased levels compare d with reactive nodes indicative of a telomerase positive tumor compon ent in Hodgkin's disease. Telomerase positivity of the Hodgkin's and R eed-Sternberg cells in vivo was also supported by high levels of telom erase expression in Hodgkin's disease cell lines, Based on our data, H odgkin's lymphomas are potential targets for antitelomerase therapy. ( C) 1998 by The American Society of Hematology.