Study of Correlation between Serum Zinc Levels and Telomerase Activity in Bladder Cancer Patients

Telomerase is an active gene existing in almost all human cancerous cells. This enzyme is essential for immortality and recycling of these living cells, however it normally has not been expressed in the somatic cells. Role of zinc as a probably interfering microelement in telomerase gene expression and activity in human bladder cancer is the main subject of this study. Thirty three voided urine samples were gathered from patients, which were previously identified as bladder carcinoma cases using cytological methods. They had previously not given any treatment. Telomerase activity was determined using polymerase chain reaction, which refers to the telomeric repeat amplification protocol. In order to distinguish the fine signals, obtained the procedure was linked to an ELISA system (TRAP assay). The patients’ grades and stages were determined independently through cystoscopy. Also, the serum zinc levels of these patients and control groups measured by atomic absorption spectrophotometer (AAS). As a result; 17 (51%) of the 33-bladder carcinoma tested patients revealed positive results for cytology, whereas using TRAP assay presence of the telomerase was positive in all of the tested bladder carcinoma cases. Only 30% (3 of 10) of the grade I tumors, 83.3% (5 of 6) of the grade II tumors and 50% (9 of 18) of the grade III tumors were diagnosed by cytology. The detection accuracy rates was statistically significant (100% for telomerase vs. 51% for cytology). The difference of relative telomerase activity (RTA) values between grades I, II and III was not statistically significant. Difference of serum zinc levels between the cases and control groups were significant (p= 0.04). Zinc levels in the both affected genders had dominant decreases, besides this shift was slightly more significant (p=0.04) in the female patients. In all, there was an inverse significant correlation between the RTA and serum zinc level in the case group (r= -0.060, p= 0.48). In conclusion our results showed a reverse relationship between zinc deficiency and increasing telomerase activity in our series of bladder cancer.