A link between serum levels of zinc and copper with relative telomerase activity in lung cancer

Abstract

Objective: Lung cancer is the leading cause of cancer-related death in men and women worldwide. The expression of various genes, particularly the telomerase gene, is affected by different factors in lung cancer. Main objective of current study was to investigate correlation between serum levels of zinc and copper, and their ratio with relative telomerase activity. Material and methods: In a case-control study, involving 50 lung cancer patients in the case group and 20 patients suffering from non-cancerous lung disease in the control group, telomerase activity was measured through TRAP assay in biopsy specimens of pulmonary tumoral tissue. In addition, serum levels of zinc and copper were measured using atomic absorption spectrometry. Results: Cancer patients had significantly higher serum level of copper than the control group (p < 0.05), as well as lower zinc level. The average copper/zinc ratio was significantly higher in cancer patients than in the control group (p < 0.05). The relative telomerase activity was significantly different between the cancer and the control groups (p < 0.01). Patients with small cell carcinoma had significantly higher copper level and relative telomerase activity compared to that of non small cell carcinoma (p < 0.05). Based on findings of current study, it is suggestible that levels of copper and zinc maybe have diagnostic and prognostic significance in pulmonary cancer. Conclusions: In conclusion, the exact mechanism(s) underlying the correlation between serum copper and zinc with telomerase activity need to be clarified in the future.