Telomerase activity in ovarian tumors

BACKGROUND. Shortening of telomeres occurs with each cell division and eventually results in cell death. The activity of telomerase, an enzyme that catalyzes telomere elongation, has been detected in germ cell lines and cancer cells, and has been detected in immortal cell lines but not in normal somatic cells. The relationship between telomerase expression and ovarian carcinogenesis was investigated. METHODS. Ovarian tissue was obtained from 41 women with ovarian tumors (10 benign, 6 borderline-malignant, and 25 malignant tumors) and 6 with uterine disease (2 with uterine myoma and 4 with uterine carcinoma). These specimens were analyzed for telomerase activity and telomere length by the telomeric repeat amplification protocol and Southern blot hybridization, respectively. RESULTS. Telomerase activity was detected in 23 of 25 malignant ovarian tumors (92%), in 1 of 6 borderline-malignant tumors (16.7%), and in 2 of 10 benign tumors (20%) (both of which were germ cell tumors). Weak telomerase activity was present in the cortex of normal ovaries from premenopausal women, and appeared to be attributable to follicles. Telomerase activity in malignant and poorly differentiated tumors tended to be higher than that in other tumors. Terminal restriction fragment length ranged between 8 and 13 kilobase pairs (kbp) for normal ovaries, and was <8 kbp in 1 of 6 malignant Stage I tumors (16.7%), 1 of 2 Stage II tumors (50%), and 9 of 17 Stage III tumors (52.9%). CONCLUSIONS. Telomerase activity may be a useful marker for the diagnosis of ovarian tumors. (C) 1997 American Cancer Society.