Triple quadrupole mass spectrometry comparative DNA adductomics of Hep G2 cells following exposure to safrole. (January 2019)

• Record Type: Journal Article
• Authors: Takeshita, Toshihide; Tao, Fumiya; Kojima, Nobuhiko; Kanaly, Robert A.
• Is Part Of: Toxicology letters. Volume 300(2019)
• Page Start: 92
• Page End: 104
• Publication Date: 2019-01
• Subjects: DNA adducts -- Hep G2 -- Safrole -- DNA adductomics -- LC/ESI-MS/MS; Toxicology -- Periodicals; 363.179
• DOI: 10.1016/j.toxlet.2018.10.023
• Languages: English
• ISSNs: 0378-4274

Abstract

Graphical abstract: Highlights: Triple quadrupole MS comparative DNA adductomics was used as a screening tool. Putative DNA adducts were detected in Hep G2 cells after safrole exposure. Interpretable product ion mass spectra were obtained by CID of adduct candidates. At least five bulky DNA adducts from safrole exposure were proposed. Abstract: A DNA adduct screening pipeline was constructed to apply triple quadrupole mass spectrometry comparative DNA adductomics to investigate the effects of the naturally-occurring plant constituent, safrole (4-allyl-1, 2-methylenedioxybenzene), on human hepatoma cells, Hep G2. DNA from Hep G2 cells that were exposed to or not exposed to safrole were digested to 2′-deoxynucleosides and analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) whereby the neutral loss of 2′-deoxyribose was targeted by monitoring the [M+H] + > [M+H – 116] + transition over a defined range. Comparative analyses through construction of DNA adductome maps revealed numerous putative DNA adduct candidates. Targeted product ion scan investigations allowed for detailed fragmentation ion analyses and the identities of at least five bulky alkylated adducts of 2′-deoxyguanosine and 2′-deoxyadenosine with molar masses greater than 400 Da each were proposed. All adducts were derived from safrole exposure and pathways to explain the occurrence of these adducts in Hep G2 cells through metabolism of safrole are discussed. This study demonstrates the potential utility of constructing triple quadrupole MS comparative DNA adductomics pipelines to screen chemicals for DNA adducts by using human cell lines.