β-Carotene interaction with NNK in the AJ-mouse model: Effects on cell proliferation, tumor formation and retinoic acid responsive genes

We studied the influence of β-carotene on the tobacco smoke carcinogen 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumor development in the A/J-mouse model. The normally low β-carotene absorption was facilitated with a diet enriched in fat and bile salt, resulting in plasma and lung tissue levels similar to humans.