Telomerase in urological malignancy

Purpose: Telomerase is a ribonucleoprotein enzyme that compensates for the progressive erosion of chromosomal ends, called telomeres. In most somatic cells telomerase expression is repressed and telomeres progressively shorte n after each cell division, causing cell senescence, Conversely telomerase is active in most human cancers, maintaining the integrity of chromosome en ds and representing an important step in cell immortalization and carcinoge nesis. The large and increasing interest in telomerase was motivated by the demonstration that more than 90% of human cancers are telomerase positive, whereas most normal tissues or benign tumors contained low or undetectable telomerase activity. We addressed the most recent data on telomerase detec tion in urological malignancy. Approaches to telomerase inhibition as a fut ure anti-cancer therapy are also discussed. Materials and Methods: We comprehensively reviewed the most recent and sign ificant publications in this field using current issues of specific journal s and a MEDLINE search. Results: Telomerase is often expressed in bladder (90%), prostate (80%) and renal (69%) carcinoma. A variable but significant percent of normal tissue s from tumor adjacent zones or noncancer samples are positive for telomeras e. The clinical role of telomerase is still questionable in renal cancer, w hile important insights into the diagnostic role of telomerase in bladder a nd prostate carcinoma are increasing. Telomerase detection in exfoliated ce lls collected with urine or bladder washings seems a promising tool for the diagnosis and management of bladder cancer. Conclusions: Larger perspective studies of larger groups of patients are re quired to discover an appropriate role for telomerase when assessing these tumors. The improvement of quantitative methods to evaluate the expression of telomerase is a cornerstone in the complete clarification of the clinica l relevance of telomerase.