Association of nitrosamine-derived radioactivity with nuclear and mitochondrial DNA in mice.

In order to better understand the carcinogenic process, a comparative study was undertaken of the association of nitrosamine-derived radioactivity with nuclear and mitochondrial DNA isolated from tumor-susceptible and non-tumor-susceptible tissues of two strains of mice with different susceptibilities to tumor induction by dimethylnitrosamine (DMN) or diethylnitrosamine (DEN). A single dose of either [14C]-DMN or [14C]DEN was administered by intragastric intubation to young adult male RFM or BALB/c mice. The DNA isolated from the mitochondrial fraction of tumor-susceptible tissues bound several times (10 to 90) more nitrosamine than the nuclear DNA. These results suggest that mitochondrial DNA may be a target in the carcinogenic process induced by nitrosamine compounds.