The effect of selenium, zinc and copper on the excretion of urinary modified nucleobases in rats treated with prostate cancer cells

Abstract Given the strong associations between diet and cancer risk, there is considerable scientific interest in determining whether dietary factors associated with prostate cancer cell implantation may influence epigenetic alternations. The aim of the research was to assess impact of selected trace elements (selenium, zinc and copper) on the kinetics of changes (10-13-14-21 week of life cycle of rats) in the level of 7-methylguanine, 3-methyladenine, 1-methylguanine and 8-oxo-guanine in the urine of rats with implanted prostate cancer cells (LNCaP). Modified nucleobases were determined by validated high performance liquid chromatography coupled to mass spectrometry (LC-MS/MS) method using multiple reaction monitoring (MRM) mode. In the presented model the implantation of rats with cancer cells did not affect the level of the examined biomarkers in the rats’ urine. The level of methyl derivatives was statistically significantly reduced with the age of the examined rats. The implantation of rats with cancer cells results in the appearance of tumors in 71% of the rats obtaining the standard diet and respectively in 25% of those supplemented with selenium. Supplementation with selenium affects both the effectiveness of tumor induction and the concentration of 7-MeG, 3-MeA, 1-MeG and 8-oxoG in urine of the examined rats. These findings show that modified nucleosides can play an important role in cancer prevention.