The effect of some trace elements on the expression of telomerase gene in lung cancer.

Lung cancer is a disorder that begins due to genetic and epigenetic changes. These changes cause the activation of oncogenes and the inactivation of tumor suppressor genes. Various factors influence the expression of these genes. In this research, we investigated the relationship between the number of trace elements zinc and copper and the ratio of these two in serum with the expression of the telomerase enzyme gene in lung cancer. For this purpose, we included 50 people with lung cancer in the study as the case group and 20 patients with non-tumor lung diseases as the control group. The TRAP assay method measured the telomerase activity in biopsy samples of lung tumor tissue. Also, serum copper and zinc were measured by atomic absorption spectrometry. The results showed that the mean serum concentration of copper and the ratio of copper to zinc in patients were significantly higher than in the controls (120.8 ± 5.7 versus 107.2 ± 6.5μg/dL)(P<0.05). However, there is no significant difference in the mean serum concentration of zinc between the two groups (p > 0.05). The patients' mean ratio of copper to zinc is significantly higher than the control group (1.6 ± 0.4 versus 1.1 ± 0.2)(p < 0.05). The average level of telomerase enzyme activity of patients showed a significant difference from the control group 32.8 ± 16.1 vs. zero percent) (p < 0.01). There is a direct and significant correlation between the serum level of copper and the level of telomerase enzyme activity in patients (r = 0.36 and p < 0.05). A positive correlation was observed between total serum copper concentration and the increasing age of patients (r = 0.39 and p < 0.01). The correlation between the ratio of copper to zinc and the serum copper concentration of the patients was positive and significant (r = 0.36 and p < 0.05), but the correlation between the amount of serum zinc and the ratio of copper to zinc was negative and significant (r = -0/ 72 and p < 0.01). The average copper serum concentration of people with small cell carcinoma (123.7 ± 2.8 μg/dL) compared to non-small cell carcinoma (117.6 ± 4.8 μg/dL) is high and significant (P< 0.05). Patients with small cell carcinoma had a high mean telomerase concentration (112 ± 0.57%) and significantly compared to non-small cell carcinomas (6.4 ± 2.5%)(P < 0.05). This situation regarding the zinc element and the ratio of copper to zinc in non-small cell carcinomas compared to small cell carcinomas were evaluated as non-significant (P>0.05). Based on the obtained results, it can be assumed that determining the amount of zinc and copper and the telomerase enzyme activity in lung cancer can have a biological role in the initiation and progression of tumor tissue, which requires more studies.