Telomerase activity in benign and malignant cytologic fluids

BACKGROUND. Telomerase is a ribonucleoprotein that maintains telomeric base pair repeats at the ends of mammalian chromosomes during DNA replication. Telomerase is expressed in various human tumors, some normal tissues, and i mmortalized cell lines. The assay of telomerase activity has potential as a n adjunct for cancer (detection in cytologic fluids. METHODS. Twenty-four unfixed cytologic fluids, including 13 ascitic fluids, 7 pleural fluids, 3 pelvic washings, and 1 bronchial washing, were prepare d for polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (Oncor, Inc., Gaithersburg, MD). Telomerase activity was determine d by PCR. The presence of a ladder of products with 6 base pair increments, separated by polyacrylamide gel electrophoresis and detected by phosphoima ging, was considered a positive result. Results were compared with cytologi c evaluation of alcohol fixed, Papanicolaou stained smears. RESULTS. Of the 14 cytologically malignant specimens, 11 (79%) contained de tectable telomerase activity. Two cytologically malignant samples could not be evaluated for telomerase activity due to the presence of inhibitory sub stances of PCR reaction. Of the 10 cytologically negative specimens, 1 (10% ) was positive for telomerase activity; this specimen was from a patient wi th history of both endometrial and lung carcinomas. CONCLUSIONS, Telomerase activity can be detected in malignant cytologic spe cimens and thus has potential as a diagnostic adjunct in cytopathology. (C) 1999 American Cancer Society.