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Molecular models in nickel carcinogenesis
W Bal1, H Kozłowski, K S Kasprzak
1Faculty of Chemistry, University of Wrocław, Poland. wbal@wchuwr.chem.uni.wroc.pl
Abstract:
Nickel compounds are known human carcinogens, but the exact molecular mechanisms of nickel carcinogenesis are not known. Due to their abundance, histones are likely targets for Ni(II) ions among nuclear macromolecules. This paper reviews our recent studies of peptide and protein models of Ni(II) binding to histones. The results allowed us to propose several mechanisms of Ni(II)-inflicted damage, including nucleobase oxidation and sequence-specific histone hydrolysis. Quantitative estimations of Ni(II) speciation, based on these studies, support the likelihood of Ni(II) binding to histones in vivo, and the protective role of high levels of glutathione. These calculations indicate the importance of histidine in the intracellular Ni(II) speciation.
Insights
Nickel (Ni(II)) ions are human carcinogens. Studies suggest Ni(II) may damage DNA by binding to histones, potentially through nucleobase oxidation and histone hydrolysis, with glutathione offering protection.
Area of Science:
- Environmental toxicology
- Molecular carcinogenesis
- Biochemistry
Background:
- Nickel compounds are recognized human carcinogens.
- The precise molecular mechanisms underlying nickel-induced cancer remain largely unknown.
- Histones, abundant nuclear proteins, are potential targets for nickel ions (Ni(II)) within the cell.
Purpose of the Study:
- To review recent studies on Ni(II) binding to histones using peptide and protein models.
- To elucidate potential molecular mechanisms of Ni(II)-induced damage to histones and DNA.
- To quantitatively assess Ni(II) speciation and its implications for in vivo interactions.
Main Methods:
- Utilized peptide and protein models to study Ni(II) interactions with histones.
- Proposed mechanisms of Ni(II)-inflicted damage based on experimental findings.
- Performed quantitative estimations of Ni(II) speciation under cellular conditions.
Main Results:
- Identified potential damage mechanisms including nucleobase oxidation and sequence-specific histone hydrolysis.
- Quantitative speciation studies support the likelihood of Ni(II) binding to histones in vivo.
- High levels of glutathione appear to play a protective role against Ni(II) toxicity.
Conclusions:
- Ni(II) binding to histones is a plausible mechanism for nickel carcinogenesis.
- Proposed mechanisms of DNA and histone damage provide insight into nickel toxicity.
- Intracellular Ni(II) speciation is influenced by histidine and potentially modulated by glutathione.