<i>p16</i>promoter methylation in Pb²⁺-exposed individuals

Abstract

BACKGROUND: One of the principle symptoms of lead poisoning is the development of neurological disorders. Neuronal response is closely related to DNA methylation changes. Aim. In this study, we estimated p16 methylation in nine individuals exposed to lead using methylation-specific polymerase chain reaction followed by analysis of the methylated cytosine content of the product by thermal denaturation. RESULTS: We found that, based on lead blood concentration, lead-exposed individuals were divided into two groups. Among highly exposed individuals (blood Pb(2+) concentration = 51-100 microg/dL), we observed complete CpG methylation, whereas for low Pb(2+) concentrations (blood Pb(2+) concentration = 6-11 microg/dL), we observed partial methylation. CONCLUSION: Our results show that among lead-overexposed individuals, p16 methylation is frequent and extensive, and suggest that DNA methylation could be involved in the mechanism by which lead induces neurotoxicity.