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IARC Scientific Publications 1999Malondialdehyde is a naturally occurring product of lipid peroxidation and prostaglandin biosynthesis which is mutagenic and carcinogenic. It reacts with DNA to form... (Review)
Review
Malondialdehyde is a naturally occurring product of lipid peroxidation and prostaglandin biosynthesis which is mutagenic and carcinogenic. It reacts with DNA to form adducts to deoxyguanosine and deoxyadenosine. The major adduct to DNA is a pyrimidopurinone called pyrimido[1,2-a]purin-10(3H)-one (M1G). Studies of site-specific mutagenesis indicate that M1G is mutagenic in bacteria and is repaired by the nucleotide excision repair pathway. M1G has been detected in liver, leukocytes, pancreas and breast from healthy human beings at levels ranging from 1 to 120 per 10(8) nucleotides. Several assays for M1G have been described which are based on mass spectrometry, 32P-postlabelling or immunochemical techniques. M1G appears to be a major endogenous DNA adduct in human beings that may contribute significantly to cancer linked to lifestyle and dietary factors. Recent advances in the chemistry and biology of M1G are reviewed.
Topics: Breast; Carcinogens; DNA Adducts; DNA Damage; Female; Humans; Leukocytes; Liver; Malondialdehyde; Mass Spectrometry; Models, Chemical; Mutagenesis, Site-Directed; Mutagens; Neoplasms; Pancreas
PubMed: 10626205
DOI: No ID Found -
Food and Chemical Toxicology : An... Nov 2021Acrylamide (AA) is a carcinogen formed during thermal food processing and can cause tumors in rodents while its carcinogenic potency in humans is unclear. Metabolic...
Acrylamide (AA) is a carcinogen formed during thermal food processing and can cause tumors in rodents while its carcinogenic potency in humans is unclear. Metabolic conversion of AA leads to glycidamide (GA) forming N7-GA-guanine (N7-GA-Gua) as the major DNA adduct in rodents while no such adducts were found in human tissues so far. In a cohort of 56 healthy volunteers adduct levels were determined in peripheral blood mononuclear cell (PBMC) DNA and anthropometric, dietary, and biochemical parameters were measured or inquired using a questionnaire. In the majority of PBMC DNA samples the levels found were above one adduct/10 nucleosides not being correlated to dietary habits including coffee consumption, or to blood glucose levels or hemoglobin HbA1c. However, adduct levels were significantly correlated with the body mass index (BMI) and showed a continuous increase over three BMI classes. Our findings indicate a background of AA-derived DNA adducts present in humans in PBMC related to body mass rather than to certain dietary or lifestyle factors.
Topics: Acrylamide; Adult; Body Mass Index; Carcinogens; DNA; DNA Adducts; Female; Humans; Leukocytes, Mononuclear; Male; Middle Aged; Young Adult
PubMed: 34560178
DOI: 10.1016/j.fct.2021.112575 -
Regulatory Toxicology and Pharmacology... Aug 1996A workshop was held to discuss the uses of data on DNA adduct measurement in humans and in experimental systems in vitro and in vivo. The discussions focused principally... (Review)
Review
A workshop was held to discuss the uses of data on DNA adduct measurement in humans and in experimental systems in vitro and in vivo. The discussions focused principally on the understanding of the toxicological significance of DNA adducts as provided by information from animal models. An Expert Panel concluded that human DNA adduct data have utility in several aspects of risk assessment. The presence and amount of specific adducts that can be correlated with a chemical exposure are relevant for hazard identification and risk evaluation. Data from experimental systems have established dose-response relationships between the level of adducts and exposure, but these remain complex and depend on metabolic fate. Although structure-activity relationships have been useful retrospectively to explain the DNA-reactive nature of some chemicals or classes of chemicals, there are currently no means outside the laboratory to specifically predict the adduct-producing potency of a compound. Analysis of DNA adducts in tissues of laboratory animals and humans has revealed sensitive subpopulations, a finding that has important relevance for human risk assessment. Adduct analysis may be one of the best tools available to characterize exposures to DNA from complex mixtures for purposes of epidemiological investigation. Consensus statements were developed based on presentations by R. Gupta, W. Lutz, R. Nath, and B. Singer [see Regul. Toxicol. Pharmacol. 23(1), 1996] and subsequent discussions. First, rigorous scientific criteria should be met for the detection and characterization of specific DNA adducts in vitro and in target tissues in vivo. Second, the use of adduct data in risk extrapolation has the greatest value when there is characterization of adduct structure, an understanding of the role of repair in DNA adduct removal, and demonstration of biological relevance for each adduct. Third, the detection of DNA adducts in a tissue does not necessarily indicate a specific tumorigenic risk for that tissue. Fourth, the mutagenic potency for specific adducts varies by several orders of magnitude. Fifth, the role of DNA adducts induced by exogenous agents must be placed in perspective of endogenously produced adducts. The biological significance of a type of DNA adduct is related to several factors, including the efficiency of conversion to mutation, the amounts of similar endogenous adducts, and the variety of exogenous DNA adducts found in DNA from humans. The biological relevance of DNA adducts may be deduced from the dose-response relationships for adducts and tumors at physiologically relevant doses as well as from data showing mutations in targets such as oncogenes or tumor suppressor genes. There is convincing evidence in the literature for an association between some specific DNA adducts, mutation, and the carcinogenic process. As a general conclusion, the Panel suggested that the current technological capabilities for detection of DNA adducts exceed our ability to define the biological significance of adducts as it relates to toxicity or health outcome. DNA adducts are likely to play an important role in human risk for cancer induction and progression, but the quantitative aspects of this relationship remain to be determined.
Topics: Animals; Carcinogens; DNA Adducts; DNA Damage; DNA Repair; Diet; Dose-Response Relationship, Drug; Environmental Exposure; Humans; In Vitro Techniques; Mutation; Risk Assessment; Tissue Distribution
PubMed: 8921541
DOI: 10.1006/rtph.1996.0059 -
Toxicology Letters Nov 2011Acrylamide (AA) is produced in many types of food products cooked or processed at high temperature. AA is metabolized to the epoxide glycidamide (GA), which can bind to...
Acrylamide (AA) is produced in many types of food products cooked or processed at high temperature. AA is metabolized to the epoxide glycidamide (GA), which can bind to deoxyguanosine and deoxyadenosine in DNA. The GA-derived N7-guanine and N3-adenine adducts are the only products which so far have been analysed in vivo. Because of previous excellent experience from analysis of adducts to N1-adenine, the aim of our study was to investigate if the N1-adenine adduct of GA could be used as a biomarker of AA exposure. A ³²P-postlabelling method was developed and tested (a) on DNA modified in vitro with GA, (b) on cells treated with GA and (c) on liver DNA from mice treated with AA. The N1-adenine adduct of GA (analysed after conversion to N⁶-GA-deoxyadenosine-5'-monophosphate) was easily detected in DNA reacted with GA and in DNA from cells exposed to GA, but not in DNA from mice treated with AA. The reason for this is currently not clearly understood, but some of the possible contributing factors are discussed. The application of the method in other experimental conditions should be further pursued in order to solve this matter.
Topics: Acrylamide; Animals; CHO Cells; Chromatography, High Pressure Liquid; Cricetinae; Cricetulus; DNA Adducts; Deoxyadenosines; Epoxy Compounds; Humans; Leukocytes, Mononuclear; Mice; Spectrophotometry, Ultraviolet
PubMed: 21878374
DOI: 10.1016/j.toxlet.2011.08.007 -
Neuro Endocrinology Letters Oct 2008Ellipticine is a potent antineoplastic agent exhibiting multiple mechanisms of its action. Recently, we have found that 13-hydroxyellipticine, formed from ellipticine as...
OBJECTIVES
Ellipticine is a potent antineoplastic agent exhibiting multiple mechanisms of its action. Recently, we have found that 13-hydroxyellipticine, formed from ellipticine as the predominant metabolite in human livers, is bound to deoxyguanosine in DNA, generating the major DNA adduct in vivo and in vitro. The development of the methods suitable for the preparation of this adduct in the amounts sufficient for identification of its structure and those for its isolation and partial characterization is the aim of this study.
METHODS
High performance liquid chromatography (HPLC) was employed for separation of 13-hydroxyellipticine-mediated deoxyguanosine adduct. The 32P-postlabeling technique was utilized to detect this adduct in DNA.
RESULTS
The formation of the 13-hydroxyellipticine-derived deoxyguanosine adduct in DNA in vitro was increased under the alkaline pH of the incubations and by the formation of the sulfate and acetate conjugates of 13-hydroxyellipticine generated by reactions with 3'-phosphoadenosine-5'-phosphosulfate (PAPS) or acetyl-coenzyme A (acetyl-CoA) catalyzed by human sulfotransferases (SULTs) 1A1 and 1A2 and N,O-acetyltransferases (NATs) 1 and 2. The HPLC method suitable for separation the 13-hydroxyellipticine-derived deoxyguanosine adduct from other reactants, deoxyguanosine and 13-hydroxyellipticine, was developed. The structure of this adduct is proposed to correspond to the product formed from ellipticine-13-ylium with the exocyclic 2-NH2 group of guanine in DNA.
CONCLUSIONS
The data are the first report on HPLC isolation of the deoxyguanosine adduct formed by 13-hydroxyellipticine in DNA and its partial characterization.
Topics: Acetyl Coenzyme A; Arylamine N-Acetyltransferase; Arylsulfotransferase; Autoradiography; Catalysis; DNA; DNA Adducts; Deoxyguanosine; Ellipticines; Hydrogen-Ion Concentration; Indicators and Reagents; Isoenzymes; Phosphoadenosine Phosphosulfate
PubMed: 18987592
DOI: No ID Found -
Carcinogenesis Apr 1997The antigenotoxic and chemopreventive effect of Aloe barbadensis Miller (polysaccharide fraction) on benzo[a]pyrene (B[a]P)-DNA adducts was investigated in vitro and in...
The antigenotoxic and chemopreventive effect of Aloe barbadensis Miller (polysaccharide fraction) on benzo[a]pyrene (B[a]P)-DNA adducts was investigated in vitro and in vivo. Aloe showed a time-course and dose-dependent inhibition of [3H]B[a]P-DNA adduct formation in primary rat hepatocytes (1x10(6) cells/ml) treated with [3H]B[a]P (4 nmol/ml). At concentrations of 0.4-250 microg/ml aloe, the binding of [3H]B[a]P metabolites to rat hepatocyte DNA was inhibited by 9.1-47.9%. Also, in rat hepatocytes cultured for 3-48 h with aloe (250 microg/ml) and [3H]B[a]P (4 nmol/ml), [3H]B[a]P-DNA adducts were significantly reduced by 36% compared with [3H]B[a]P alone. Aloe also inhibited cellular uptake of [3H]B[a]P in a dose-dependent manner at a concentration of 0.4-250 microg/ml by 6.3-34.1%. After a single oral administration of B[a]P to male ICR mice (10 mg/mouse), benzo[a]pyrene diol epoxide I (BPDE-I)-DNA adduct formation and persistence for 16 days following daily treatment with aloe (50 mg/mouse) were quantitated by enzyme-linked immunosorbent assay using monoclonal antibody 8E11. In this animal model, BPDE-I-DNA adduct formation was significantly inhibited in various organs (liver, kidney, forestomach and lung) (P < 0.001). When mice were pretreated with aloe for 16 days before B[a]P treatment, inhibition of BPDE-I-DNA adduct formation and persistence was enhanced. Glutathione S-transferase activity was slightly increased in the liver but cytochrome P450 content was not affected by aloe. These results suggest that the inhibitory effect of aloe on BPDE-I-DNA adduct formation might have a chemopreventive effect by inhibition of B[a]P absorption.
Topics: Aloe; Animals; Benzo(a)pyrene; Cells, Cultured; Chemoprevention; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme System; DNA Adducts; Glutathione Transferase; Liver; Male; Mice; Mice, Inbred ICR; Plant Extracts; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Subcellular Fractions; Tritium
PubMed: 9111213
DOI: 10.1093/carcin/18.4.771 -
Biochimica Et Biophysica Acta Mar 1997The extent of formation and repair of promutagenic (+)-anti-BPDE-N2-dG in transcriptionally active thymidine kinase (tk) gene insert and vector DNA fragments was...
The extent of formation and repair of promutagenic (+)-anti-BPDE-N2-dG in transcriptionally active thymidine kinase (tk) gene insert and vector DNA fragments was assessed in the (+)-anti-BPDE treated plasmid p220-tk within the Escherichia coli hosts of varying repair potential. Polyclonal antibody (BP1), specific for (+)-anti-BPDE DNA adduct, was utilized for quantitative estimation of this bulky lesion in nanograms amounts of membrane transblotted DNA fragments. A carcinogen dose-dependent quantitative antibody binding response, due to selective recognition of the major (+)-anti-BPDE adduct, was seen with various DNA fragments separated by gel electrophoresis. The sensitivity of the immunodetection at 0.2 fmol (+)-anti-BPDE DNA adduct, allowed a linear detection in the range of modification level of 0.64 x 10(-7) to 86 x 10(-7) adducts per nucleotide in plasmid DNA. Based on this sensitivity, detection of 0.07 and 0.46 (+)-anti-BPDE DNA adducts in respective tk and vector DNA fragments was achieved upon immunoanalysis of the in vitro modified DNA. Adduct concentration dependent antibody binding was independent of size of the vector or insert fragments. Antibody binding response, to DNA modified in vivo, was dependent upon the dose of (+/-)-anti-BPDE to plasmid DNA replicating within bacterial hosts. The repair of (+)-anti-BPDE DNA adducts was determined as the loss of antibody binding sites in the specific fragments of plasmid DNA within host E. coli. About 50% of the initial DNA damage was repaired from the individual fragments during 15 min post-incubation in the repair-proficient (wild-type) E. coli cells. Complete adduct removal occurred in approx. 60 min of post-incubation period. A significant (91%) decrease in the survival of mutant (uvrA- recA-) cells was observed at 4 microM (+/-)-anti-BPDE treatment without any reduction in the colony forming units in the wild-type cells. On the contrary, no repair was seen in the excision repair-deficient (uvrA-) E. coli cells. The results indicate (1) the selectivity of the immunological method and the unique ability of the (+)-anti-BPDE specific antibodies to monitor the direct loss of this promutagenic base lesion from the in vivo modified DNA (2) the role of host excision repair pathway in efficient removal of adducts from bacterial genome determines the survival of the bacterial cells and (3) the repair of (+)-anti-BPDE DNA adducts in episomally replicating, transcriptionally active sequences occur at a rapid rate presumably due to the ease of accessibility of repair enzymes to lesions within DNA.
Topics: 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; DNA Adducts; DNA Damage; DNA Repair; DNA, Bacterial; Escherichia coli; Mutagenesis; Mutagens; Nucleoside-Phosphate Kinase; Plasmids; Transcription, Genetic; Transformation, Genetic
PubMed: 9116034
DOI: 10.1016/s0167-4781(96)00198-4 -
Methods in Molecular Biology (Clifton,... 2014(32)P-Postlabeling analysis is an ultra-sensitive method for the detection of DNA adducts, such as those formed directly by the covalent binding of carcinogens and...
(32)P-Postlabeling analysis is an ultra-sensitive method for the detection of DNA adducts, such as those formed directly by the covalent binding of carcinogens and mutagens to bases in DNA and other DNA lesions resulting from modification of bases by endogenous or exogenous agents (e.g., oxidative damage). The procedure involves four main steps: enzymatic digestion of the DNA sample; enrichment of the adducts; radiolabeling of the adducts by T4 kinase-catalyzed transference of (32)P-orthophosphate from [γ-(32)P]ATP; chromatographic separation of labeled adducts; and detection and quantification by means of their radioactive decay. Using 10 μg of DNA or less, it is capable of detecting adduct levels as low as 1 adduct in 10(9)-10(10) normal nucleotides. It is applicable to a wide range of investigations, including monitoring human exposure to environmental or occupational carcinogens, determining whether a chemical has genotoxic properties, analysis of the genotoxicity of complex mixtures, elucidation of the pathways of activation of carcinogens, and monitoring DNA repair.
Topics: Animals; Carcinogens; Chromatography, High Pressure Liquid; DNA Adducts; Humans; Isotope Labeling; Phosphorus Radioisotopes
PubMed: 24623224
DOI: 10.1007/978-1-62703-739-6_10 -
Mutagenesis Mar 2007The carcinogenic vehicle emission product 3-nitrobenzanthrone (3-NBA) is known to rearrange in the atmosphere to the isomer 2-nitrobenzanthrone (2-NBA), which exists in...
The carcinogenic vehicle emission product 3-nitrobenzanthrone (3-NBA) is known to rearrange in the atmosphere to the isomer 2-nitrobenzanthrone (2-NBA), which exists in 70-fold higher concentration in ambient air. The genotoxicity of 2-NBA and 3-NBA was studied both in vitro (human cell lines A549 and HepG2) and in vivo (F344 female rats intra-tracheally administered 5 mg/kg body weight of 3-NBA) models, using the (32)P-HPLC and the single-cell gel electrophoresis (Comet assay) methods. In vitro, also the parent compound benzanthrone (BA) and the metabolite 3-aminobenzanthrone (3-ABA) were evaluated. 3-NBA gave highest levels of DNA adducts in the two cell lines, but significantly higher in HepG2 (relative adduct level approximately 500 adducts/10(8) normal nucleotides), whereas 2-NBA formed about one-third and one-twentieth of the DNA adduct amount in A549 and HepG2 cells, respectively. 3-ABA formed only minute amounts of DNA adducts and only in the A549 cells, whereas BA did not give rise to any detectable levels. The DNA adduct patterns from 3-NBA were similar between the two model systems, but differed somewhat for 2-NBA. The oxidative stress induced by BA was almost as high as what was observed for 3-NBA and 3-ABA in both cell lines, and 2-NBA induced lowest level of oxidative stress. The oxidative stress and DNA adduct level, in whole blood, was significantly increased by 3-NBA but not by 2-NBA. However, 2-NBA showed similar toxicity to 3-NBA, with respect to DNA adduct formation in vivo, hence it is important to further study 2-NBA as a potential contributor to health risk. While DNA adduct level in the 3-NBA-exposed animals reached a peak around 1 and 2 days after instillation, 2-NBA-treated animals showed a tendency towards a continuing increase at the end of the study.
Topics: Air Pollutants; Animals; Benz(a)Anthracenes; Carcinogens; Cell Line; Chromatography, High Pressure Liquid; DNA Adducts; Female; Humans; Isomerism; Oxidative Stress; Rats; Rats, Inbred F344; Time Factors
PubMed: 17267818
DOI: 10.1093/mutage/gel067 -
Correlation between biomarkers of human exposure to genotoxins with focus on carcinogen-DNA adducts.Mutagenesis Jan 2008Correlations among biomarkers, an important issue in biomarker research, provide enhanced insight and understanding of the complexity of molecular mechanisms initiated... (Review)
Review
Correlations among biomarkers, an important issue in biomarker research, provide enhanced insight and understanding of the complexity of molecular mechanisms initiated by environmental genotoxic agents in the human organism. Occupational and environmental exposures mostly represent mixtures of genotoxic agents, whereas the specificity of biomarker measurements varies widely. Here, we give an overview of the correlation studies with particular emphasis on DNA adduct biomarker analysis of exposure to polycyclic aromatic hydrocarbons (PAHs) and/or tobacco smoke. We have collected data on correlations between different DNA adduct detection methods, DNA adduct structures and DNA adduct levels in human tissues. Data are also presented on the correlation between DNA adducts and other biomarkers of exposure and of early biological effects, including protein adducts, urinary metabolites and cytogenetic end points. In numerous studies, 32P-postlabelling and immunoassay measurements of DNA adducts recognized the difference between exposure groups similarly; however, at the individual level, there was, in general, not a statistically significant correlation between the two determinations. Inconsistency was found regarding the correlation between the levels of total bulky adducts and specific single DNA adduct structures. A number of studies found a positive correlation between DNA adduct levels in target and surrogate tissues, although stratification for exposure level may have influenced the results. Characteristically, there was a positive correlation between DNA adduct levels in tumour and normal tissue pairs. In general, there was a lack of correlation between DNA adducts and urinary PAH metabolites, but after stratification for particular genetic polymorphisms correlation may have emerged between the two biomarkers of exposure. The correlations with cytogenetic biomarkers were very complex, with examples of both positive correlation and lack of correlation. Exploration of correlations among biomarkers contributes to the further progress of molecular cancer epidemiology and to the selection of the optimal biomarkers for the investigation of human exposure to carcinogens.
Topics: Biomarkers; Carcinogens; DNA Adducts; Environmental Exposure; Humans; Mutagens
PubMed: 17989146
DOI: 10.1093/mutage/gem043