Biochemical and molecular effects of N-nitroso compounds in human cultured cells: an overview.

In-vitro models using human tissues and cells provide a bridge between studies of humans and of laboratory animals. Cultured human cells activate N-nitrosamines to DNA-damaging metabolites, including alkyldiazonium ions and aldehydes; these metabolites can also inactivate DNA repair processes, such as O6-alkylguanine DNA-alkyltransferase (AAT) activity, and are mutagenic in human cells. Both human epithelial and mesenchymal cells have been transformed in vitro by N-nitroso compounds.