Abstract
Genotoxicants originating from inflammation, diet, and environment can covalently modify DNA, possibly initiating the process of carcinogenesis. DNA adducts have been known for long, but the old methods allowed to target only a few known DNA adducts at a time, not providing a global picture of the “DNA adductome”. DNA adductomics is a new research field, aiming to screen for unknown DNA adducts by high resolution mass spectrometry (HRMS). However, DNA adductomics presents several analytical challenges such as the need for high sensitivity and for the development of effective screening approaches to identify novel DNA adducts. In this work, a sensitive untargeted DNA adductomics method was developed by using ultra-high performance liquid chromatography (UHPLC) coupled via an ESI source to a quadrupole-time of flight mass spectrometric instrumentation. Mobile phases with ammonium bicarbonate gave the best signal enhancement. The MS capillary voltage, cone voltage, and detector voltage had most effect on the response of the DNA adducts. A low adsorption vial was selected for reducing analyte loss. Hybrid surface-coated analytical columns were tested for reducing adsorption of the DNA adducts. The optimized method was applied to analyse DNA adducts in calf thymus, cat colon, and human colon DNA by performing a MSE acquisition (all-ion fragmentation acquisition) and screening for the loss of deoxyribose and the nucleobase fragment ions. Fifty-four DNA adducts were tentatively identified, hereof 38 never reported before. This is the first untargeted DNA adductomics study on human colon tissue, and one of the few untargeted DNA adductomics studies in the literature reporting the identification of such a high number of unknowns. This demonstrates promising results for the application of this sensitive method in future human studies for investigating novel potential cancer-causing factors.
Original language | English |
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Article number | 126985 |
Journal | Talanta |
Volume | 282 |
Number of pages | 10 |
ISSN | 0039-9140 |
DOIs | |
Publication status | Published - 2025 |
Bibliographical note
Funding Information:This work, and the fellowship of Giorgia La Barbera, was supported by the European Commision for the H2020 Marie Curie Slodowska Individual Fellowships (grant n\u00B0 843892) and by a Weiman Stipend (K\u00F8bmand i Odense Johann og Hanne Weimann, f. Seedorffs Legat). Professor Lars Ove Dragsted was supported by a Semper Ardens grant (CF15-0574) from the Carlsberg Foundation and by the PRIMA grant on gut abiotic factors from the NOVO-Nordisk Foundation (NNF190C0056246).
Publisher Copyright:
© 2024 The Authors
Keywords
- Colon tissue
- DNA adductomics
- Liquid chromatography
- Mass spectrometry
- Untargeted