Analysis of telomerase as a diagnostic biomarker of cervical dysplasia and carcinoma

Telomerase expression is a potentially important marker of high-grade cervical dysplasia and squamous cell carcinoma (SCC). The routine practice of cervical cytology is limited by problems of false negative diagnoses as well as by poor specificity for clinically significant lesions in patients with low-grade cytologic abnormalities. Telomerase is widely expressed in most SCCs as well as in a high proportion of high-grade squamous intraepithelial lesions. Histochemical studies have confirmed that telomerase is expressed in the lower portions of normal or metaplastic squamous mucosa but that telomerase positive cells extend into the upper epithelial layers in cases of high-grade dysplasia. Since the cervical smear samples the uppermost cell layers of the cervical mucosa, but does not normally include cells derived from the lower layers of the squamous mucosa, the detection of telomerase in exfoliated cells of the cervical smear may have specificity for clinically significant lesions. The analysis of hTR, hTERT, and telomerase activity are complicated by a number of technical factors that may lead to either false negative or false positive test results. Thus, the practical application of telomerase analysis as a diagnostic adjunct for cervical cytopathology may depend on the development of more reliable and sensitive assay systems, possibly formatted for cytochemical applications.