Telomerase Activity in Voided Urine: a Potential Marker of Human Bladder Carcinoma / 대한비뇨기과학회지

ABSTRACT

PURPOSE: Telomerase is an enzyme that immortalizes cells by maintaining a constant telomere length, and is thought to be active in the transformation of normal somatic cells into immortal human tumor cells. In an attempt to get a more valuable, noninvasive assay for the detection of bladder carcinomas, exfoliated cells from the voided urine of patients for the presence of telomerase were assayed. MATERIALS AND METHODS: Voided urine samples were obtained from 37 patients with known, but untreated, bladder carcinomas and 20 healthy volunteers to determine the presence of telomerase activity. Telomerase activity was analyzed using a PCR-based telomeric repeat amplification protocol (TRAP)-ELISA method. RESULTS: Of the 37 bladder carcinoma samples, 30 (81.1%) and 16 (43.2%) tested positive for the presence of telomerase activity and cytology, respectively (p=0.009). However, for the 20 healthy volunteers samples, no telomerase activity was found. 83.3% (5 of 6) of the grade 1 tumors, 75.0% (18 of 24) of the grade 2 tumors and 100% (7 of 7) of the grade 3 tumors were positive for telomerase activity. Only 33.3% (2 of 6) of the grade 1 tumors, 45.8% (11 of 24) of the grade 2 tumors and 42.9% (3 of 7) of the grade 3 tumors were diagnosed by cytology. For the low (Tis, Ta, T1) and high (T2, T3) stages, the sensitivities were 77.8 and 100, and 37.0 and 60.0% for telomerase activity and cytology, respectively. All of T1 and T2 patients, with carcinoma in situ, and Ta (100%) were also positive for telomerase activity. There was no significant correlation between the urinary telomerase activity and clinicopathological characteristics of bladder carcinomas, with the exception of the multiplicity of the tumor. CONCLUSIONS: These findings suggest that urinary telomerase activity may be a potential marker for detecting bladder carcinomas, especially in low grade or stage tumors.