Effect of Zinc, Selenium and Copper in cell line of breast cancer on telomerase gene expression

Telomerase is a RNA dependent DNA polymerase which synthesis telomeric repeats and in most cases are molecular base of unlimited proliferation. Telomerase gene expression occurs in most tumor cells rather than normal cells. Combination of external and internal factors including Zn, Cu and Selenium are involved in breast tumor development and growth. The aim of this study was to evaluate the effect of Zinc, Selenium and Copper on telomerase gene expression in breast cancer T47D cell line. Time and dose dependent manner treatment of T47D breast cancer cell lines were carried out by adding Zn, Cu, and Selenium in tissue culture. Relative telomerase activity (RTA) of T47D cell line was measured by TRAP assay. After being treated with 100 μM/L Zn So4 for 6 hours, telomerase activity of T47D cells was markedly increased (5.2 fold) but with 100 μM /L Zn So4 for 24 hours and 500 μM /L Zn So4 for 6, 24 hours, telomerase activity was 0.76, 0.39 and 0.12℅ respectively (control 49.2℅). After being treated with 10 μM /L Cu So4 for 6 hours, telomerase activity of T47D cells 3.67 fold was increased. After being treated with 10, 30 μM /L selenium-L- methuonin, telomerase activity were markedly inhibited. Telomerase activity of T47D cells for 24 hours were 0.93, 0.60 and for 48 hours were 0.76, 0.12 respectively (control 49.2℅). Based on obtained results, it is speculated that pharmacologic doses of Se, Zn and Cu could have an inhibitory effects on telomerase gene expression and it could be used as a target therapy in tumor cells.