Hemeryck, Lieselot

Vanhaecke, Lynn

Ghent University Academic Bibliography

ASSESSMENT OF CHEMICALLY INDUCED GENOTOXICITY AND CANCER RISK BY MEANS OF DNA ADDUCTOMICSDEPARTMENT OF VETERINARY PUBLIC HEALTH & FOOD SAFETY – LAB. OF CHEMICAL ANALYSISLieselot Y. Hemeryck & Lynn VanhaeckeMethodology, Technology & ToolsThe exposure of DNA to both endogenous and exogenous genotoxic chemicals can result inthe formation of DNA adducts and is believed to be the first step in chemically inducedcarcinogenesis. DNA adductomics is a fairly recently breached branch of metabolomicswhich studies the formation of DNA adducts as a result of exposure of cellular DNA to a widevariety of chemicals in day to day life. To facilitate targeted as well as untargeted DNAadduct analysis, we optimized and validated a unique state-of-the-art Ultra High PerformanceLiquid Chromatography - High Resolution Mass Spectrometry based methodology usinghybrid Quadrupole-Orbitrap technology (Q-ExactiveTM). In addition, to allow in-depthinvestigation of diet-related DNA adduct formation, a DNA adduct database, containingmore than 150 known diet-related DNA adducts, was constructed (L.Y. Hemeryck et al., 2015,Anal Chim Acta).Current research focusIn 2015, the International Agency for Research on Cancer and the World Health Organizationissued that red meat is ‘probably carcinogenic to humans’ and processed meat is‘carcinogenic to humans’. More specifically, epidemiological research has demonstrated thatred meat consumption significantly contributes to colorectal cancer (CRC) risk. Differenthypotheses have been put forward to explain this causal relationship but the heme hypothesis,stating that heme iron present in red meat stimulates the formation of genotoxic N-nitrosocompounds (NOCs) and lipid peroxidation products (LPOs), has received the mostsupport. Both NOCs and LPOs can exert DNA damaging effects, but the exact underlingmechanisms of red meat and heme iron genotoxicity still require further elucidation. In light ofthis, we successfully applied the in-house DNA adductomics platform to investigate red meatinduced DNA adduct formation in several in vitro and in vivo experimental setups.WorkflowContactLynn.Vanhaecke@UGent.beLieselotY.Hemeryck@UGent.bewww.vvv.ugent.beSalisburylaan 133, B-9820 MerelbekeDNA adductomics platformDNA hydrolysis0.1 M FA at 80 °C during30 minDNA adduct extractionSPE: Oasis HLB 1cc, 30 mg1 2UHPLC-HRMS analysisQ-Exactive: Quadrupole-Orbitrap3Data processing & interpretation4TargetedDNA adduct analysis:By means of XcaliburTM softwarev NOC-related DNA adducts:• O6-carboxymethylguanine O6-methylguanine v LPO-related DNA adducts: • Pyrimidopurinone• MethylhydroxypropanoguanineUntargetedDNA adductome mapping:By means of ToxFinderTM, SieveTM & SimcaTM softwarev ToxFinderTM:• Match m/z of retrieved ions to in-house DNA adduct database• Univariate statisticsv SieveTM & SimcaTM:• Alignment and framing of ion intensities• Multivariate statistics (OPLS-DA)• Match m/z of relevant ions to in-house DNA adduct database Case study: rat feeding trialExperimental setup24 Sprague-Dawley rats were divided into 4randomly composed groups and either fed a lowor high fat beef diet, or a low or high fatchicken diet during 14 consecutive days. Aftertissue sampling, the DNA adductome of liver,duodenum and colon were mapped.DNA adduct profilingFigure on the right:Heat map of average (n=6) DNA adduct typesand levels in rat liver, duodenal and colon DNA.Darker shades of blue represent higheraverage DNA adduct levels. RT representsretention time in min., an asterix marks adifferent isomer of a certain DNA adduct that hadalready been detected at an earlier RT. A grey boxrepresents the total absence of DNA adductdetection in those particular samples. Theionization mode in which each DNA adduct typewas detected, is provided between brackets aftereach DNA adduct name.ResultsExtensive data processing by means of different‘omics’ software packages allowed a thoroughevaluation of the (significant) effects of thedigestion of the different meat based diets on theDNA adductome in rat liver, duodenum andcolon. We observed that the DNA adductomediffered in each tissue type. More importantly,rats on a different meat diet demonstrated adifferent DNA adduct profile. Intake of beefand/or lard induced a significant rise in thelevels of 22 DNA adduct types. These particulartypes of DNA adducts were formed due toalkylation and/or oxidation of DNA nucleobases.As such, their formation is of particular interest tothe red and processed meat-CRC hypotheses.Obtained output(Markers for) red meat genotoxicityVia the execution of several independent red meatgenotoxicity studies (in vitro & in vivo) (Vanden Busscheet al., 2014, Mol Nutr Food Res; Hemeryck et al., 2015,Toxicol Res; Hemeryck et al. 2017, Food Chem; Hemerycket al., 2017, Food Chem Toxicol, subm.), the in-house DNAadductomics platform has allowed us to study red meatinduced genotoxicity and pinpoint 7 DNA adducts withsignificant marker potential (listed in the table below).Future perspectivesv Human in vivo confirmation of the obtained results(case-control CRC study + dietary intervention study).v Integration of the DNA adductomics platform withMetabolomics, Lipidomics & Metagenomicsè Fused omicsDNA adduct type DNA adduct originO6-Carboxymethyl-G AlkylationDimethyl-T or ethyl-T AlkylationMethyl-G AlkylationMalondialdehyde-2x-G Lipid peroxidationHeptenal-G Lipid peroxidationCarbamoylhydroxyethyl-G AlkylationMalondialdehyde-3x-C Lipid peroxidation

Assessment of chemically induced genotoxicity and cancer risk by means of DNA adductomics

Hemeryck, LieselotDI040000602355828020012583090000-0002-2451-337501FC9C02-F0EE-11E1-A9DE-61C894A0A6B4

Vanhaecke, LynnDI040019990969458010019509690000-0003-0400-2188F77AFAE4-F0ED-11E1-A9DE-61C894A0A6B4

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https://biblio.ugent.be/publication/8574560/file/8574562.pdf

Assessment of chemically induced genotoxicity and cancer risk by means of DNA adductomics

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Ghent University Academic Bibliography

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