Early life exposure to N-nitrosamine drives genotoxicity, mutagenesis, and tumorigenesis in DNA repair-deficient mice

Lindsay B Volk, Monét Norales, Callie Karjane, Joshua J Corrigan, Alper J Alcaraz, Lee J Pribyl, Nicolette A Bugher, Megan Blawas, Isabella Dulski, Einthavy Arunachalam, Nina Gubina, Emily Michelsen, Kannammai Pichappan, Natalya Yakimchuk, Matilda Swanson, Duanduan Ma, Stuart S Levine, Desiree L Plata, Robert G Croy, Leona D Samson, John M Essigmann, Carole L Yauk, Sebastian E Carrasco, Bevin P Engelward

Abstract: N-Nitrosodimethylamine (NDMA) is a probable human carcinogen found in contaminated pharmaceuticals and drinking water, yet the impact of age on NDMA susceptibility remains poorly understood. Using DNA repair-deficient (Aag-/-;Mgmt-/-) and wild-type mice, we systematically compared the effects of NDMA exposure in juveniles and adults. Juvenile Aag-/-;Mgmt-/- mice were profoundly more vulnerable, exhibiting persistent DNA damage,inflammation, and mutations that led to liver pathology and tumorigenesis, particularly in males. Adults, by comparison, were resistant to NDMA. Wild-type mice showed similar, attenuated trends. NDMA-induced DNA adduct levels were comparable across age groups, implicating proliferation-dependent responses to adducts, rather than adduct formation, as the primary driver of age-related risk. Supporting this mechanism, triiodothyronine-stimulated cell proliferation in adults partially recapitulated juvenile sensitivity, linking cell division to NDMA genotoxicity. Our findings identify developmental stage, sex, and DNA repair capacity as key modifiers of NDMA-induced carcinogenesis, with potential implications for environmental risk assessment and regulatory policy.

DOI: https://doi.org/10.1038/s41467-026-71753-w

Data Availability:

• Supporting data deposited to Zenodo (DOI: 10.5281/zenodo.19122403)
• Sequencing data (FASTQ) are available at NCBI SRA (BioProject PRJNA1422080)
• Duplex sequencing variant calls and RNAseq analysis code/data are available on Code Ocean (DOI: 10.24433/CO.3406581.v1)
• Raw images deposited to Omero