Correlation between Serum Levels of Zinc and Copper and Telomerase Gene Expression in Lung Cancer Patients

Lung cancer is the leading cause of cancer related death in men and women in world wide. In molecular biology of lung cancer, different genes particularly telomerase gene expression seems to be under regulation of variety of factors. The aim of this study was to evaluate the correlation between serum levels of Zn, Cu, and their ratio and telomerase gene expression in lung cancer patients. In this cross sectional study, 50 subjects with lung cancer and 20 patients with lung disease were recruited. The concentration of Zn and Cu were measured by atomic Absorption Spectrophotometry (AAS). Telomerase gene expression was carried out using TRAP Assay. The mean serum levels of Cu and the ration of Cu/Zn were significantly higher in lung cancer patients than non tumor lung disease (120.8 ± 5.70 vs. 107.20± 6.50 ug/dl) and (1.6 ±0.4 vs. 1.1 ±0.2) respectively (p<0.05). The mean serum levels of Zn were not significant between two groups. The Mean relative activity of telomerase as indirect telomerase gene expression, was significantly higher in lung cancer subjects than controls (32.80 ±16.10 vs. 0.00 percent) (p<0.01). There was a relatively positive correlation between telomerase activity and Cu concentration in lung cancer patients(r = 0.36, p<0.05). There was a positive and significant correlation between Cu levels and age (r = 0.39, p<0.01) and the Cu/Zn ratio and Cu concentration (r = 0.36, p<0.05). However, there was a reverse and highly significant correlation between Cu/Zn ration and Zn concentration (r = -0.72, p 0.01). In categorized lung carcinomas, the mean concentration of Cu was higher in small cell lung carcinoma (123.70 ±2.8 ug/dl) than in nonsmall cell lung carcinoma (117.60 ±4.8 ug /dl) and this difference was significant (p<0.05). Telomerase activity was significantly higher in small cell lung carcinoma (112 ±0.57 percent) than non-small cell lung carcinoma (6.4 ±2.5 percent) (p<0.05). There was no difference in Zn and Cu/Zn ration in categorized lung cancer patients. It is speculated that evaluation of Zn, Cu in lung tumors could have some biological function in telomerase gene expression which indicate initiation and progression of tumor tissues.