Effect of magnesium on nickel-induced genotoxicity and cell transformation

'To whom reprint requests should be sent Raising the extracellular level of magnesium ions inhibited nickel-induced DNA strand breaks, DNA-protein crosslinks, sister chromatid exchanges, chromosomal aberrations and cell transformation. Carcinogenic nickel ions preferentially damaged centromeres and other heterochromatic regions of Chinese hamster ovary cell chromosomes. Elevation of extra-cellular magnesium levels prevented the effects of nickel on heterochromatin and inhibited cell transformation, but did not substantially reduce the DNA damage induced by nickel in euchromatic regions. This study suggests that hetero-chromatic DNA damage may be important to the nickel-induced neoplastic transformation process