New Insights in Telomerase and Telomeric Proteins and Their Clinical Application to Urological Cancers

Abstract

Telomerase is a ribonucleoproteic enzymatic complex that catalyzes the addition of telomeric repeats to the end of chromosome DNA, thus preventing the loss of telomeric sequences that normally occurs at each cell division. In presence of telomerase activity integrity of chromosome length is maintained, cell replication is not limited, and the cells are practically immortal. Nearly all human cancers have stabilized telomeres and approximately 85% of them have increased telomerase expression. Several studies have evaluated the expression of telomerase assay and concluded that the induction of telomerase activity is a late event associated primarily with invasive cancer and rarely with precursor lesions. The evidence that telomerase expression is not a mere association with tumor development, but represents a contributing factor to carcinogenesis itself comes now from several studies.

This manuscript reviews the main applications of telomerase detection in urological malignancies, either through the direct measurement of the activity of the enzyme or, indirectly, with the assay of its catalytic subunit hTERT mRNA. The detectability of both these parameters in urine sediment appears an appealing tool in the diagnosis and follow up of urological tumors, especially of bladder carcinoma. The feasibility of anticancer therapy based on telomerase inhibition is also briefly discussed.