Adductomics · Novel DNA adductomics methodological developments for research in colon cancer

Covalent modCovalent modification of DNA by exogenous genotoxic molecules can translate into gene alteration, possibly inducing carcinogenesis. The analysis of DNA modifications, referred to as DNA-adducts, is fundamental for assessing the mechanism of action of genotoxic molecules. Nowadays, high resolution mass spectrometry (HRMS) is one of the most promising technique for DNA-adduct identification. Despite DNA adductomics by HRMS is highly promising, it is a new born field, presenting several analytical challenges and requiring the development of sample preparation protocols, chromatographic and mass spectrometric methods, and identification approaches. So far the majority of DNA adductomics studies were done in vitro or in animals with few studies in humans. Colorectal cancer (CRC) is considered to be highly affected by exogenous genotoxicants. Smoking, consumption of alcohol, and meat intake only explain a minor part of sporadic CRC. The mechanism of DNA modification leading to CRC has not yet been elucidated but should provide new clues about causative factors. Therefore, a DNA adductomics approach will be used in this project. Hybrid ion mobility - quadrupole - time-of-flight HRMS instrumentation will be used to develop the analytical procedures using resected colon and colon biopsies as well as urine from subjects affected by CRC or familial adenomatous polyposis (FAP), the last showing high adduct levels and very high CRC risk. High levels of DNA-adducts in FAP will increase chances of adduct identification. Urine will be used to identify DNA-adduct excretion products. The developed methods will then be used in a case-control human study with the aim of finding a correlation between specific DNA-adduct formation or specific excretion products and CRC, possibly identifying novel cancer risk biomarkers. Expanding the knowledge on DNA-adducts related to CRC could provide new opportunities for the design of more effective intervention and prevention approaches.