TELOMERASE EXPRESSION IN NORMAL EPITHELIUM, REACTIVE ATYPIA, SQUAMOUSDYSPLASIA, AND SQUAMOUS-CELL CARCINOMA OF THE UTERINE CERVIX

Telomerase activity has been detected in a broad range of human malign ant neoplasms, and its expression may represent an essential step in t he malignant transformation of tissues; however, the expression of tel omerase in premalignant lesions remains relatively unexplored. We test ed tissue sections of cervical squamous cell carcinomas and squamous i ntraepithelial lesions, samples of benign reactive atypia, and normal cervical mucosa from hysterectomy and cone biopsy specimens for the ex pression of telomerase. Mirror-image sections from each sample were pa raffin embedded and processed for histologic analysis. The test sample s of cervical tissue were crushed under liquid nitrogen, and telomeras e activity was determined by the telomeric repeat amplification protoc ol. Telomerase activity was detected in 18 of 18 cases (100%) of invas ive squamous cell carcinoma. Twenty-five of 26 samples (96%) of high-g rade squamous intraepithelial lesion also tested positively for telome rase activity, including 10 of 10 samples of moderate dysplasia, 12 of 13 samples of severe dysplasia, and 3 of 3 samples of carcinoma in si tu. Telomerase activity was detected in 14 of 25 samples (56%) of low- grade squamous intraepithelial lesion and in 10 of 18 samples (56%) of reactive atypia but was detected in only 9 of 50 samples (18%) of his tologically normal cervical mucosa. These results suggest that telomer ase expression may be a marker of premalignant and malignant squamous cell lesions of the uterine cervix, although it is also expressed in a high proportion of eases of reactive atypia.