Published in Cancer Detection and Prevention 2002; 26(2).

Detection of telomerase-positive circulating epithelial cells in ovarian cancer patients

Eva Sapi, PhDa, N.I. Okpokwasili, MSa, T. Rutherford, MDb

aDepartment of Therapeutic Radiology HRT22J, Yale University School of Medicine, P.O. Box 208040. New Haven, CT 06520-8040, USA b Department of Obstetrics Gynecology, Yale University School of Medicine, P.O. Box 208040, New Haven, CT 06520-8040, USA

Accepted 12 February 2002

The aim of this study is the detection of circulating tumor cells in peripheral blood of ovarian cancer patients. We applied immunomagnetic beads coated with an epithelial or leukocyte-specific antibody to isolate epithelial cells from peripheral blood and we measured their telomerase activity. Both enrichment methods showed high sensitivity and specificity to isolate ovarian tumor cells from peripheral blood. Our data also suggested that disseminated ovarian tumor cells isolated from ascites consistently express telomerase enzyme. We have tested epithelial cell enriched blood samples from 20 stage III patients, 8 stage IV patients and 30 healthy volunteers for telomerase activity. Telomerase activity was detectable in the blood samples of all stage IV patients (100%) and seven stage III patients (35%), but none of the healthy donors. Our results showed that CA-125 level, an established diagnostic marker for ovarian cancer, is significantly higher in lelomerase-positive patients than telomerase-negative patients. In summary, our data demonstrated that this non-invasive blood test is sensitive and specific for detecting disseminated ovarian epithelial cells and telomerase is a potential marker for the detection of circulating ovarian tumor cells.

KEY WORDS: Immunomagnetic enrichment methods, Serum markers, .