TELOMERASE ACTIVITY AS A NOVEL MARKER OF LUNG-CANCER AND IMMUNE-ASSOCIATED LUNG-DISEASES

Telomerase maintains telomere length and is considered to be necessary for the indefinite proliferation of human cells. Telomerase activity is detected not only in germline and immortal cancer cells, but also i n stem/progenitor cells of renewal tissues and activated lymphocytes. While it is generally agreed that telomerase is a useful tumor marker, the utility of telomerase activity in non-cancerous cells should also be considered. In the present study, we quantitatively examined telom erase activity in 56 cytology samples and 106 bronchoalveolar lavage s amples obtained from patients with various respiratory diseases. Fourt een of 34 samples obtained from lung cancer patients showed detectable telomerase activity, while only 7 of 128 samples obtained from patien ts without lung cancer did (p<0.001). Moreover, 12 of 14 telomerase-po sitive samples with lung cancer showed strong signals, while none with out lung cancer did. Among 106 non-cancerous bronchoalveolar lavage sa mples, 4 telomerase positive samples had increased number of lymphocyt es and increased disease progression. These findings indicate that eva luation of telomerase activity may not only be a useful diagnostic tes t for lung cancer, but may also be a marker of disease aggressiveness for immune-associated lung diseases.