Activation of the human c-Ha-ras-1 proto-oncogene by in-vitro reaction with N-nitrosomethyl(acetoxymethyl)amine

Abstract

Reaction of N-nitrosomethyl(acetoxymethyl)amine in vitro in the presence of esterase with a plasmid containing the human c-Ha-ras-1 gene has been shown to generate a transforming oncogene when the methylated DNA is transfected into NIH 3T3 cells. Our results show that an activated nitrosamine can mutate a normal cellular proto-oncogene, a reaction that may be the necessary first step in the multistage process of tumour induction.