Metabolism and DNA Adduct Formation of Tobacco-Specific N-Nitrosamines

The tobacco-specific N-nitrosamines 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK) and N '-nitrosonornicotine (NNN) always occur together and exclusively in tobacco products or in environments contaminated by tobacco smoke. They have been classified as carcinogenic to humans by the International Agency for Research on Cancer. In 1998, we published a review of the biochemistry, biology and carcinogenicity of tobacco-specific nitrosamines. Over the past 20 years, considerable progress has been made in our understanding of the mechanisms of metabolism and DNA adduct formation by these two important carcinogens, along with progress on their carcinogenicity and mutagenicity. In this review, we aim to provide an update on the carcinogenicity and mechanisms of the metabolism and DNA interactions of NNK and NNN.

Automated summary

NNK and NNN are tobacco-specific nitrosamines that have been identified as carcinogens for humans. Significant progress has been made in understanding their metabolism, DNA adduct formation, carcinogenicity, and mutagenicity over the past 20 years. This review aims to provide an update on the carcinogenicity and mechanisms of metabolism and DNA interactions of NNK and NNN.