Levels Of Bulky DNA Adducts Research Articles

Cruciferous Vegetable Intake and Bulky DNA Damage within Non-Smokers and Former Smokers in the Gen-Air Study (EPIC Cohort).

Epidemiologic studies have indicated that cruciferous vegetables can influence the cancer risk; therefore, we examined with a cross-sectional approach the correlation between the frequent consumption of the total cruciferous vegetables and the formation of bulky DNA damage, a biomarker of carcinogen exposure and cancer risk, in the Gen-Air study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. DNA damage measurements were performed in the peripheral blood of 696 of those apparently healthy without cancer controls, including 379 never-smokers and 317 former smokers from seven European countries by the 32P-postlabeling assay. In the Gen-Air controls, the median intake of cruciferous vegetables was 6.16 (IQR 1.16–13.66) g/day, ranging from 0.37 (IQR 0–6.00) g/day in Spain to 11.34 (IQR 6.02–16.07) g/day in the UK. Based on this information, participants were grouped into: (a) high consumers (>20 g/day), (b) medium consumers (3–20 g/day) and (c) low consumers (<3.0 g/day). Overall, low cruciferous vegetable intake was correlated with a greater frequency of bulky DNA lesions, including benzo(a)pyrene, lactone and quinone-adducts and bulky oxidative lesions, in the adjusted models. Conversely, a high versus low intake of cruciferous vegetables was associated with a reduction in DNA damage (up to a 23% change, p = 0.032); this was particularly evident in former smokers (up to a 40% change, p = 0.008). The Generalized Linear Regression models indicated an overall Mean Ratio between the high and the low consumers of 0.78 (95% confidence interval, 0.64–0.97). The current study suggests that a higher intake of cruciferous vegetables is associated with a lower level of bulky DNA adducts and supports the potential for cancer prevention strategies through dietary habit changes aimed at increasing the consumption of cruciferous vegetables.

Modulation of smoke-induced DNA and microRNA alterations in mouse lung by licofelone, a triple COX-1, COX-2 and 5-LOX inhibitor.

Chronic inflammation plays a crucial role in the carcinogenesis process and, in particular, in smoking-related carcinogenesis. Therefore, anti-inflammatory agents provide an interesting perspective in the prevention of smoking-associated cancers. Among nonsteroidal anti-inflammatory drugs (NSAIDs), licofelone is a triple inhibitor of both cyclooxygenases (COX-1 and COX-2) and of 5-lipooxygenase (5-LOX) that has shown some encouraging results in cancer prevention models. We previously showed that the dietary administration of licofelone, starting after weanling, to Swiss H mice exposed for 4 months to mainstream cigarette smoke since birth attenuated preneoplastic lesions of inflammatory nature in both lung and urinary tract, and had some effects on the yield of lung tumors at 7.5 months of age. The present study aimed at evaluating the early modulation by licofelone of pulmonary DNA and RNA alterations either in smoke-free or smoke-exposed H mice after 10 weeks of exposure. Licofelone protected the mice from the smoke-induced loss of body weight and significantly attenuated smoke-induced nucleotide alterations by decreasing the levels of bulky DNA adducts and 8-hydroxy-2'-deoxyguanosine in mouse lung. Moreover, the drug counteracted dysregulation by smoke of several pulmonary microRNAs involved in stress response, inflammation, apoptosis, and oncogene suppression. However, even in smoke-free mice administration of the drug had significant effects on a broad panel of microRNAs and, as assessed in a subset of mice used in a parallel cancer chemoprevention study, licofelone even enhanced the smoke-induced systemic genotoxic damage after 4 months of exposure. Therefore, caution should be paid when administering licofelone to smokers for long periods.

Bulky DNA adduct levels in normal-appearing colon mucosa, and the prevalence of colorectal adenomas

Purpose: Examine the association between bulky DNA adduct levels in colon mucosa and colorectal adenoma prevalence, and explore the correlation between adduct levels in leukocytes and colon tissue.Methods: Bulky DNA adduct levels were measured using 32P-postlabelling in biopsies of normal-appearing colon tissue and blood donated by 202 patients. Multivariable logistic regression was used to examine associations between DNA adducts, and interactions of DNA adduct-DNA repair polymorphisms, with the prevalence of colorectal adenomas. Correlation between blood and tissue levels of DNA adducts was evaluated using Spearman’s correlation coefficient.Results: An interaction between bulky DNA adduct levels and XPA rs1800975 on prevalence of colorectal adenoma was observed. Among individuals with lower DNA repair activity, increased DNA adduct levels were associated with increased colorectal adenoma prevalence (OR = 1.41 per SD increase, 95%CI: 0.92–2.18). Conversely, among individuals with normal DNA activity, an inverse association was observed (OR = 0.60 per SD increase, 95%CI: 0.34–1.07). Blood and colon DNA adduct levels were inversely correlated (ρ = −0.20).Conclusions: Among genetically susceptible individuals, higher bulky DNA adducts in the colon was associated with the prevalence of colorectal adenomas. The inverse correlation between blood and colon tissue measures demonstrates the importance of quantifying biomarkers in target tissues.

Exposure to meat-derived carcinogens and bulky DNA adduct levels in normal-appearing colon mucosa

IntroductionMeat consumption is a risk factor for colorectal cancer. This research investigated the relationship between meat-derived carcinogen exposure and bulky DNA adduct levels, a biomarker of DNA damage, in colon mucosa. MethodsLeast squares regression was used to examine the relationship between meat-derived carcinogen exposure (PhIP and meat mutagenicity) and bulky DNA adduct levels in normal-appearing colon tissue measured using 32P-postlabelling among 202 patients undergoing a screening colonoscopy. Gene-diet interactions between carcinogen exposure and genetic factors relevant to biotransformation and DNA repair were also examined. Genotyping was conducting using the MassARRAY® iPLEX® Gold SNP Genotyping assay. ResultsPhIP and higher meat mutagenicity exposures were not associated with levels of bulky DNA adducts in colon mucosa. The XPC polymorphism (rs2228001) was found to associate with bulky DNA adduct levels, whereby genotypes conferring lower DNA repair activity were associated with higher DNA adduct levels than the normal activity genotype. Among individuals with genotypes associated with lower DNA repair (XPD, rs13181 and rs1799179) or detoxification activity (GSTP1, rs1695), higher PhIP or meat mutagenicity exposures were associated with higher DNA adduct levels. Significant interactions between the XPC polymorphism (rs2228000) and both dietary PhIP and meat mutagenicity on DNA adduct levels was observed, but associations were inconsistent with the a priori hypothesized direction of effect. ConclusionExposure to meat-derived carcinogens may be associated with increased DNA damage occurring directly in the colon among genetically susceptible individuals.

Toxic Effects of the Major Components of Diesel Exhaust in Human Alveolar Basal Epithelial Cells (A549).

We investigated the toxicity of benzo[a]pyrene (B[a]P), 1-nitropyrene (1-NP) and 3-nitrobenzanthrone (3-NBA) in A549 cells. Cells were treated for 4 h and 24 h with: B[a]P (0.1 and 1 μM), 1-NP (1 and 10 μM) and 3-NBA (0.5 and 5 μM). Bulky DNA adducts, lipid peroxidation, DNA and protein oxidation and mRNA expression of CYP1A1, CYP1B1, NQO1, POR, AKR1C2 and COX2 were analyzed. Bulky DNA adducts were induced after both treatment periods; the effect of 1-NP was weak. 3-NBA induced high levels of bulky DNA adducts even after 4-h treatment, suggesting rapid metabolic activation. Oxidative DNA damage was not affected. 1-NP caused protein oxidation and weak induction of lipid peroxidation after 4-h incubation. 3-NBA induced lipid peroxidation after 24-h treatment. Unlike B[a]P, induction of the aryl hydrocarbon receptor, measured as mRNA expression levels of CYP1A1 and CYP1B1, was low after treatment with polycyclic aromatic hydrocarbon (PAH) nitro-derivatives. All test compounds induced mRNA expression of NQO1, POR, and AKR1C2 after 24-h treatment. AKR1C2 expression indicates involvement of processes associated with reactive oxygen species generation. This was supported further by COX2 expression induced by 24-h treatment with 1-NP. In summary, 3-NBA was the most potent genotoxicant, whereas 1-NP exhibited the strongest oxidative properties.

Abstract A10: Exposure to heterocyclic aromatic amines, genetic susceptibility and bulky DNA adduct levels in blood leukocytes

Abstract Background: There is compelling evidence to suggest that aspects of diet influence cancer risk; specifically, high meat consumption is associated with elevated risks. Exposure to heterocyclic aromatic amines (HAAs), carcinogens produced in meat when cooked at high temperatures, is a hypothesized explanation for the meat-cancer relationship. Reactive HAA metabolites form adducts with DNA; left unrepaired, adducts can induce mutations which may initiate/promote carcinogenesis. Genetic differences in the ability to biotransform HAAs (as conferred by polymorphisms in CYP1A1, CYP1A2, CYP1B1, NAT1 and NAT2) and repair DNA adducts (as conferred by polymorphisms in XPA, XPD and XRCC1) is postulated to modify the dietary HAAs-DNA adduct relationship. Methods: In a cross-sectional study of 99 healthy volunteers recruited from Kingston, Ontario, Canada, dietary exposure to HAAs and bulky DNA adduct levels in blood leukocytes was investigated. A detailed questionnaire was used in combination with a mutagen database to estimate average intake of dietary HAAs. Specifically, the detailed questionnaire obtained the average frequency of consumption, usual level of doneness and usual serving size of nine commonly consumed meats items with high HAA content. Bulky DNA adduct levels were measured in blood collected after an overnight fast using 32P-postlabelling. Least squares regression was used to examine the relationship between dietary HAA exposure and bulky DNA adduct levels in blood. Gene-diet interactions between dietary HAAs and genetic factors relevant to the biotransformation of HAAs and DNA repair were also examined. Results: No main effects of dietary exposure to HAAs on bulky DNA adduct levels were observed. However, polymorphisms in NAT1 were found to associate with bulky DNA adduct levels. Specifically, those with the putative NAT1*10 rapid acetylator phenotype had a lower adduct level than those with the slow acetylator phenotype (p=0.02). Furthermore, having five or more ‘at-risk’ genotypes was associated with higher bulky DNA adduct levels (p=0.03). Gene-diet interactions were also observed between the NAT1*10 allele and dietary HAAs (p&amp;lt;0.05); specifically, among the slow acetylator phenotype, higher intakes of dietary HAAs were associated with an increase in DNA adduct levels compared to lower intakes. Conclusions: This study provides evidence of a biologic relationship between dietary HAAs, genetic susceptibility and bulky DNA adduct formation. The lack of a strong independent association between dietary HAAs and DNA adducts suggests that dietary HAAs are not a large contributor to bulky DNA adducts in this Canadian population; future studies should consider relevant gene-diet interactions to clarify the potential role of HAAs in carcinogenesis. Citation Format: Vikki Ho, Sarah Peacock, Thomas E. Massey, Roger W. L. Godschalk, Frederik-Jan van Schooten, Jian Chen, Will D. King. Exposure to heterocyclic aromatic amines, genetic susceptibility and bulky DNA adduct levels in blood leukocytes. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr A10.

Gene-diet interactions in exposure to heterocyclic aromatic amines and bulky DNA adduct levels in blood leukocytes.

Heterocyclic aromatic amines (HAAs), carcinogens produced in meat when cooked at high temperatures, are an emerging biologic explanation for the meat-colorectal cancer relationship. HAAs form DNA adducts; left unrepaired, adducts can induce mutations, which may initiate/promote carcinogenesis. The purpose of this research was to investigate the relationship between dietary HAAs, genetic susceptibility and bulky DNA adduct levels. Least squares regression was used to examine the relationship between dietary HAA exposure and bulky DNA adduct levels in blood measured using (32)P-postlabeling among 99 healthy volunteers. Gene-diet interactions between dietary HAAs and genetic factors relevant to the biotransformation of HAAs and DNA repair were also examined. No main effects of dietary HAAs on bulky DNA adduct levels was found. However, those with the putative NAT1 rapid acetylator phenotype had lower adduct levels than those with the slow acetylator phenotype (P = 0.02). Furthermore, having five or more 'at-risk' genotypes was associated with higher bulky DNA adduct levels (P = 0.03). Gene-diet interactions were observed between NAT1 polymorphisms and dietary HAAs (P < 0.05); among the slow acetylator phenotype, higher intakes of HAAs were associated with an increase in DNA adduct levels compared to lower intakes. This study provides evidence of a biologic relationship between dietary HAAs, genetic susceptibility and bulky DNA adduct formation. However, the lack of a strong main effect of HAAs suggests that dietary HAAs are not a large contributor to bulky DNA adducts in this population; future studies should consider relevant gene-diet interactions to clarify the role of HAAs in carcinogenesis.

Environmental, dietary, maternal, and fetal predictors of bulky DNA adducts in cord blood: a European mother-child study (NewGeneris).

Background:Bulky DNA adducts reflect genotoxic exposures, have been associated with lower birth weight, and may predict cancer risk.Objective:We selected factors known or hypothesized to affect in utero adduct formation and repair and examined their associations with adduct levels in neonates.Methods:Pregnant women from Greece, Spain, England, Denmark, and Norway were recruited in 2006–2010. Cord blood bulky DNA adduct levels were measured by the 32P-postlabeling technique (n = 511). Diet and maternal characteristics were assessed via questionnaires. Modeled exposures to air pollutants and drinking-water disinfection by-products, mainly trihalomethanes (THMs), were available for a large proportion of the study population.Results:Greek and Spanish neonates had higher adduct levels than the northern European neonates [median, 12.1 (n = 179) vs. 6.8 (n = 332) adducts per 108 nucleotides, p < 0.001]. Residence in southern European countries, higher maternal body mass index, delivery by cesarean section, male infant sex, low maternal intake of fruits rich in vitamin C, high intake of dairy products, and low adherence to healthy diet score were statistically significantly associated with higher adduct levels in adjusted models. Exposure to fine particulate matter and nitrogen dioxide was associated with significantly higher adducts in the Danish subsample only. Overall, the pooled results for THMs in water show no evidence of association with adduct levels; however, there are country-specific differences in results with a suggestion of an association in England.Conclusion:These findings suggest that a combination of factors, including unknown country-specific factors, influence the bulky DNA adduct levels in neonates.Citation:Pedersen M, Mendez MA, Schoket B, Godschalk RW, Espinosa A, Landström A, Villanueva CM, Merlo DF, Fthenou E, Gracia-Lavedan E, van Schooten FJ, Hoek G, Brunborg G, Meltzer HM, Alexander J, Nielsen JK, Sunyer J, Wright J, Kovács K, de Hoogh K, Gutzkow KB, Hardie LJ, Chatzi L, Knudsen LE, Anna L, Ketzel M, Haugen M, Botsivali M, Nieuwenhuijsen MJ, Cirach M, Toledano MB, Smith RB, Fleming S, Agramunt S, Kyrtopoulos SA, Lukács V, Kleinjans JC, Segerbäck D, Kogevinas M. 2015. Environmental, dietary, maternal, and fetal predictors of bulky DNA adducts in cord blood: a European mother–child study (NewGeneris). Environ Health Perspect 123:374–380; http://dx.doi.org/10.1289/ehp.1408613

Prenatal Protection: Maternal Diet May Modify Impact of PAHs

Prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) has previously been associated with higher incidence of depression, anxiety, and attention problems among highly exposed children.1,2 Although epidemiological studies have found clear associations between PAH exposure and adverse effects on fetal growth,3,4 evidence for impacts on growth has been inconsistent in biomarker-based research.5,6 A new study describes an association between prenatal PAH exposure and reduced birth weight that may be modified by mothers’ fruit and vegetable intake during pregnancy.7 PAHs are produced by incomplete combustion of diverse organic materials, including fossil fuels, tobacco, and foods.8 Once PAHs are inhaled or ingested, they are metabolized to compounds that can readily attach to DNA, forming so-called bulky DNA adducts that can set the stage for mutation and carcinogenesis.9 Bulky DNA adducts can be measured in cord blood as an indicator of a newborn’s prenatal exposure to several genotoxic agents, including PAHs.7 In the current study, the researchers used data collected for 612 newborns through the Newborns and Genotoxic Exposure Risks (NewGeneris) project, a multicenter European study investigating how contaminants in the diets of pregnant women affect their children’s health.10 The women were enrolled from 2006 to 2010 at 11 maternity units in Denmark, England, Greece, Norway, and Spain, and provided personal information and completed detailed food questionnaires. Birth information, including weight and head circumference, was gathered from medical records. Cord blood collected at birth was analyzed for levels of bulky DNA adducts at three laboratories in Hungary, Sweden, and the Netherlands.7 Figure 1 Mothers who eat a diet rich in fruits and vegetables may offer their unborn children some protection against adverse effects of PAHs. Bulky DNA adducts are not a specific biomarker but a broad biomarker, says coauthor Marie Pedersen, a postdoctoral researcher at the Centre for Research in Environmental Epidemiology in Barcelona, Spain. They are therefore well suited for studying complex exposures such as diet and traffic emissions. “I think that’s a strength for this study,” Pedersen says. The researchers categorized adduct levels as low, moderate, or high and considered several statistical models for various birth outcomes and numerous confounding factors. Analyses were conducted for the entire study population, by country, and by groupings of southern (Greece and Spain) versus northern (England, Denmark, and Norway) countries. For the entire study population, newborns in the high-adduct group had an average birth weight of 129 g less than newborns in the low-adduct group. The southern countries had, on average, higher adduct levels and lower birth weights than the northern group, but high adduct levels were associated with high, not low, birth weight. (Pedersen says the adducts in the south may reflect different exposures than those in the north, or there may have been some protective factor involved in the southern pregnancies.) In women with low intakes of fruits and vegetables, there was a stronger association between high adduct levels and low birth weight (an estimated 248-g reduction for high versus low adduct levels) than there was among women with high fruit and vegetable intakes (an estimated 58-g decrease for high versus low adduct levels). Radim J. Sram, head of the Department of Genetic Ecotoxicology at the Institute of Experimental Medicine AS CR in Czech Republic, who was not involved with the study, says of his own research on PAHs and human health, “According to our experience, you get better information about the quality of fruits and vegetables intake when you measure vitamin C and E in the plasma, than when you calculate it according to the answers in questionnaires.” Pedersen and her colleagues indicate that further study is needed to test and possibly expand on their findings. “I’m already doing the analysis for the next study, and I can see that there are many modifiable factors that we can work on,” says Pedersen.

Xenobiotic metabolism induction and bulky DNA adducts generated by particulate matter pollution in BEAS-2B cell line: geographical and seasonal influence

Airborne particulate matter (PM) toxicity is of growing interest as diesel exhaust particles have been classified as carcinogenic to humans. However, PM is a mixture of chemicals, and respective contribution of organic and inorganic fractions to PM toxicity remains unclear. Thus, we analysed the link between chemical composition of PM samples and bulky DNA adduct formation supported by CYP1A1 and 1B1 genes induction and catalytic activities. We used six native PM samples, collected in industrial, rural or urban areas, either during the summer or winter, and carried out our experiments on the human bronchial epithelial cell line BEAS-2B. Cell exposure to PM resulted in CYP1A1 and CYP1B1 genes induction. This was followed by an increase in EROD activity, leading to bulky DNA adduct formation in exposed cells. Bulky DNA adduct intensity was associated to global EROD activity, but this activity was poorly correlated with CYPs mRNA levels. However, EROD activity was correlated with both metal and polycyclic aromatic hydrocarbon (PAH) content. Finally, principal components analysis revealed three clusters for PM chemicals, and suggested synergistic effects of metals and PAHs on bulky DNA adduct levels. This study showed the ability of PM samples from various origins to generate bulky DNA adducts in BEAS-2B cells. This formation was promoted by increased expression and activity of CYPs involved in PAHs activation into reactive metabolites. However, our data highlight that bulky DNA adduct formation is only partly explained by PM content in PAHs, and suggest that inorganic compounds, such as iron, may promote bulky DNA adduct formation by supporting CYP activity.

The GSTM1null (deletion) and MGMT84 rs12917 (Phe/Phe) haplotype are associated with bulky DNA adduct levels in human leukocytes

Tobacco smoke and air pollutants contain carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and tobacco specific nitrosamines (TSNA), that are substrates of metabolizing enzymes generating reactive metabolites that can bind to DNA. Variation in the activity of these enzymes may modify the extent to which these metabolites can interact with DNA. We compared the levels of bulky DNA adducts in blood leukocytes from 93 volunteers living in Mexico City with the presence of 13 single nucleotide polymorphisms (SNPs) in genes related to PAH and TSNA metabolism (AhR rs2044853, CYP1A1 rs1048943, CYP1A1 rs1048943, CYP1A1 rs1799814, EPHX1 rs1051740, EPHX1 rs2234922, GSTM1 null, GSTT1 null and GSTP1 rs947894), DNA repair (XRCC1 rs25487, ERCC2 rs13181 and MGMT rs12917) and cell cycle (TP53 rs1042522). 32P-postlabeling analysis was used to quantify bulky DNA adduct formation. Genotyping was performed using PCR-RFLP. The mean levels of bulky DNA adducts were 8.51±3.66 adducts/108 nucleotides (nt) in smokers and 8.38±3.59 adducts/108 nt in non-smokers, being the difference not statistically significant. Without taking into account the smoking status, GSTM1null individuals had a marginally significant lower adduct levels compared with GSTM1 volunteers (p=0.0433) and individuals heterozygous for MGMT Leu/Phe had a higher level of bulky adducts than those who were homozygous wild type (p=0.0170). A multiple regression analysis model showed a significant association between the GSTM1 (deletion) and MGMT rs12917 (Phe/Phe) haplotype and the formation of DNA adducts in smokers (R2=0.2401, p=0.0215). The presence of these variants conferred a greater risk for higher adduct levels in this Mexican population.

MATERNAL, DIETARY AND ENVIRONMENTAL PREDICTORS OF BULKY DNA ADDUCTS IN CORD BLOOD: A EUROPEAN MOTHER–CHILD STUDY (NEWGENERIS).

Background: Bulky DNA adducts in cord blood reflect prenatal effective dose of exposure to genotoxic compounds such as polycyclic aromatic hydrocarbons, provide a reliable biomarker of genotoxic damage and possibly cancer risk. Little is known on sources of exposures resulting in these adducts particularly in neonates. Aims: We examined maternal, dietary and environmental predictors of bulky DNA adduct levels in neonates to better understand our previous finding of an association between higher adduct levels and lower birth weight. Methods: Pregnant women from Greece, Spain, England, Denmark and Norway were recruited in 2006-2010. Adducts were measured by the 32P-postlabelling technique in cord white blood cells (n=511). Maternal diet and other personal characteristics were assessed via questionnaires. Land-use regression models were used to estimate individual exposure to air pollution. Results: Adduct levels tended to be higher in neonates born to women who smoked as compared with those of non-smokers (10.0 (n=81) vs. 7.6 (n=424) adducts per 108 nucleotide, p=0.10). Spanish and Greek neonates had higher adduct levels than the Northern Europeans (12.7 (n=237) vs. 7.0 (n=373) adducts per 108 nucleotides, p&lt;0.001). Neonates born during June-August had the highest adduct levels. Higher maternal pre-pregnancy body-mass index, births during June-August, and high maternal intake of cured and smoked meat was associated with higher adduct levels (p&lt;0.05). A protective effect of maternal intake of fruits rich in vitamin C was also found (p=0.03). Ambient air pollution (PM2.5) at the home address during pregnancy was not associated with adduct levels in Greece and England. Estimation of air pollution is ongoing in the other countries and a complete analysis will be presented. Conclusions: These findings suggest that prenatal exposures from maternal lifestyle and so far unknown country-specific factors influence the bulky DNA adduct formation in neonates. Acknowledgement: NewGeneris and ESCAPE (EU FOOD-CT-2005-016320 and 211250).

95 Exposure to polycyclic aromatic hydrocarbons and sperm DNA integrity of coke oven workers

The objective of this study was to examine sperm DNA integrity of coke-oven workers in relation to exposure to PAHs from coke processing. A total of 72 human subjects participated...

Bulky DNA Adducts in Cord Blood, Maternal Fruit-and-Vegetable Consumption, and Birth Weight in a European Mother–Child Study (NewGeneris)

Background: Tobacco-smoke, airborne, and dietary exposures to polycyclic aromatic hydrocarbons (PAHs) have been associated with reduced prenatal growth. Evidence from biomarker-based studies of low-exposed populations is limited. Bulky DNA adducts in cord blood reflect the prenatal effective dose to several genotoxic agents including PAHs.Objectives: We estimated the association between bulky DNA adduct levels and birth weight in a multicenter study and examined modification of this association by maternal intake of fruits and vegetables during pregnancy.Methods: Pregnant women from Denmark, England, Greece, Norway, and Spain were recruited in 2006–2010. Adduct levels were measured by the 32P-postlabeling technique in white blood cells from 229 mothers and 612 newborns. Maternal diet was examined through questionnaires.Results: Adduct levels in maternal and cord blood samples were similar and positively correlated (median, 12.1 vs. 11.4 adducts in 108 nucleotides; Spearman rank correlation coefficient = 0.66, p < 0.001). Cord blood adduct levels were negatively associated with birth weight, with an estimated difference in mean birth weight of –129 g (95% CI: –233, –25 g) for infants in the highest versus lowest tertile of adducts. The negative association with birth weight was limited to births in Norway, Denmark, and England, the countries with the lowest adduct levels, and was more pronounced in births to mothers with low intake of fruits and vegetables (–248 g; 95% CI: –405, –92 g) compared with those with high intake (–58 g; 95% CI: –206, 90 g)Conclusions: Maternal exposure to genotoxic agents that induce the formation of bulky DNA adducts may affect intrauterine growth. Maternal fruit and vegetable consumption may be protective.Citation: Pedersen M, Schoket B, Godschalk RW, Wright J, von Stedingk H, Törnqvist M, Sunyer J, Nielsen JK, Merlo DF, Mendez MA, Meltzer HM, Lukács V, Landström A, Kyrtopoulos SA, Kovács K, Knudsen LE, Haugen M, Hardie LJ, Gützkow KB, Fleming S, Fthenou E, Farmer PB, Espinosa A, Chatzi L, Brunborg G, Brady NJ, Botsivali M, Arab K, Anna L, Alexander J, Agramunt S, Kleinjans JC, Segerbäck D, Kogevinas M. 2013. Bulky DNA adducts in cord blood, maternal fruit-and-vegetable consumption, and birth weight in a European mother–child study (NewGeneris). Environ Health Perspect 121:1200–1206; http://dx.doi.org/10.1289/ehp.1206333

Nucleotide Excision Repair Is Not Induced in Human Embryonic Lung Fibroblasts Treated with Environmental Pollutants

The cellular response to genotoxic treatment depends on the cell line used. Although tumor cell lines are widely used for genotoxicity tests, the interpretation of the results may be potentially hampered by changes in cellular processes caused by malignant transformation. In our study we used normal human embryonic lung fibroblasts (HEL12469 cells) and tested their response to treatment with benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5 µm (PM2.5) collected in two Czech cities differing in levels and sources of air pollution. We analyzed multiple endpoints associated with exposure to polycyclic aromatic hydrocarbons (PAHs) including the levels of bulky DNA adducts and the nucleotide excision repair (NER) response [expression of XPE, XPC and XPA genes on the level of mRNA and proteins, unscheduled DNA synthesis (UDS)]. EOMs were collected in the winter and summer of 2011 in two Czech cities with different levels and sources of air pollution. The effects of the studied compounds were analyzed in the presence (+S9) and absence (–S9) of the rat liver microsomal S9 fraction. The levels of bulky DNA adducts were highest after treatment with B[a]P, followed by winter EOMs; their induction by summer EOMs was weak. The induction of both mRNA and protein expression was observed, with the most pronounced effects after treatment with B[a]P (–S9); the response induced by EOMs from both cities and seasons was substantially weaker. The expression of DNA repair genes was not accompanied by the induction of UDS activity. In summary, our results indicate that the tested compounds induced low levels of DNA damage and affected the expression of NER genes; however, nucleotide excision repair was not induced.

Malondialdehyde-deoxyguanosine and bulky DNA adducts in schoolchildren resident in the proximity of the Sarroch industrial estate on Sardinia Island, Italy.

Air quality is a primary environmental concern in highly industrialised areas, with potential health effects in children residing nearby. The Sarroch industrial estate in Cagliari province, Sardinia Island, Italy, hosts the world's largest power plant and the second largest European oil refinery and petrochemical park. This industrial estate produces a complex mixture of air pollutants, including benzene, heavy metals and polycyclic aromatic hydrocarbons. Thus, we conducted a cross-sectional study to evaluate the prevalence of malondialdehyde-deoxyguanosine adducts in the nasal epithelium of 75 representative children, aged 6-14 years, attending primary and secondary schools in Sarroch in comparison with 73 rural controls. Additionally, the levels of bulky DNA adducts were analysed in a subset of 62 study children. DNA damage was measured by (32)P-postlabelling methodologies. The air concentrations of benzene and ethyl benzene were measured in the school gardens of Sarroch and a rural village by diffusive samplers. Outdoor measurements were also performed in other Sarroch areas and in the proximity of the industrial estate. The outdoor levels of benzene and ethyl benzene were significantly higher in the school gardens of Sarroch than in the rural village. Higher concentrations were also found in other Sarroch areas and in the vicinity of the industrial park. The mean levels of malondialdehyde-deoxyguanosine adducts per 10(8) normal nucleotides ± standard error (SE) were 74.6±9.1 and 34.1±4.4 in the children from Sarroch and the rural village, respectively. The mean ratio was 2.53, 95% confidence interval (CI): 1.71-2.89, P < 0.001, versus rural controls. Similarly, the levels of bulky DNA adducts per 10(8) normal nucleotides ± SE were 2.9±0.4 and 1.6±0.2 in the schoolchildren from Sarroch and the rural village, respectively. The means ratio was 1.90, 95% CI: 1.25-2.89, P = 0.003 versus rural controls. Our study indicates that children residing near the industrial estate have a significant increment of DNA damage.

Exposure to polycyclic aromatic hydrocarbons in women from Poland, Serbia and Italy – relation between PAH metabolite excretion, DNA damage, diet and genotype (the EU DIEPHY project)

Exposure of the general population to polycyclic aromatic hydrocarbons (PAH) is ubiquitous. The aim of this study was to analyze biomarkers associated with the uptake of PAH in 428 non-smoking women from Łodz (Poland), Viterbo (Italy), Belgrade (Serbia) and from the Pančevo area, where the petrochemical complex was destroyed by the air raids in 1999. Urinary excretion of PAH metabolites was lowest in Italian women, intermediary for Serbian and highest in Polish women, who predominantly excreted hydroxy phenanthrenes as metabolites of phenanthrene. Bulky DNA adduct levels were highest in Italian and Polish women. Genotype or PAH ambient air levels could not explain the dissimilarities between the study groups with respect to biomarker patterns, which probably reflected differences in life style-associated factors.

1-Hydroxypyrene as a biomarker for assessing the effects of exposure to polycyclic aromatic hydrocarbons on semen quality and sperm DNA integrity

A cross-sectional study was conducted to assess whether urinary 1-hydroxypyrene (1-OHP) could serve as a biomarker to assess the effect of PAHs on cellular and molecular changes of sperm. Urine and semen samples were collected from a total of 65 healthy coke oven workers. Sperm quality parameters (concentration, motility, vitality, and morphology) and semen integrity (DNA fragmentation, 8-oxodGuo, bulky DNA adducts) were analyzed. Sixteen (16) targeted PAHs at the personal breathing zone area were monitored and quantified. Results showed that urinary 1-OHP positively correlated with measured levels of 16 targeted PAHs. Urinary 1-OHP did not significantly correlate with semen quality; however, PAHs with heavy molecular weight, e.g., benzo(g,h,i)perylene and benzo(k)fluoranthene, negatively correlated with morphology and motility of sperms (p = 0.02 and 0.002, p = 0.04 and 0.04, respectively). Urinary 1-OHP positively correlated with the level of 8-oxodGuo and bulky DNA adducts, but not DNA fragmentation. Urinary 1-OHP was a suitable biomarker for an estimate of biologically effective doses of PAH exposure. However, urinary 1-OHP may not be sufficient as a biomarker to assess both cellular and molecular changes of sperm induced by PAHs.

Biomonitoring of polycyclic aromatic hydrocarbons from coke oven emissions and reproductive toxicity in nonsmoking workers

The objective of the cross-sectional study was to assess whether exposure to polycyclic aromatic hydrocarbons (PAHs) from coke oven emissions contributed to alteration of semen quality and sperm DNA integrity in nonsmoking workers. Nonsmoking coke oven workers from a steel plant in Taiwan served as the exposure groups (topside-oven workers for the high exposure group and side-oven workers for the low exposure group), and administrators and security personnel in the plant served as the control. An exposure assessment was conducted to determine both particulate and gaseous phase of PAH levels and urinary 1-hydroxypyrene (1-OHP) levels. Semen quality was analyzed according to WHO guidelines. DNA fragmentation and bulky DNA adducts were measured to assess sperm DNA integrity. There was no significant difference in sperm concentrations, vitality, and DNA fragmentation between the exposed group and the control. The high exposure group experienced significantly lower percentages of normal morphology as compared with the control (p=0.0001). Bulky DNA adducts were detected in the exposed group that were significant higher than the control (p=0.04). Exposure to PAHs from coke-oven emissions could contribute to increased levels of bulky DNA adducts in sperm.

Analysis of biomarkers in a Czech population exposed to heavy air pollution. Part I: bulky DNA adducts

The health of human populations living in industrial regions is negatively affected by exposure to environmental air pollutants. In this study, we investigated the impact of air pollution on a cohort of subjects living in Ostrava, a heavily polluted industrial region and compared it with a cohort of individuals from the relatively clean capital city of Prague. This study consisted of three sampling periods differing in the concentrations of major air pollutants (winter 2009, summer 2009 and winter 2010). During all sampling periods, the study subjects from Ostrava region were exposed to significantly higher concentrations of benzo[a]pyrene (B[a]P) and benzene than the subjects in Prague as measured by personal monitors. Pollution by B[a]P, particulate matter of aerodynamic diameter <2.5 µm (PM2.5) and benzene in the Ostrava region measured by stationary monitors was also higher than in Prague, with the exception of PM2.5 in summer 2009 when concentration of the pollutant was significantly elevated in Prague. To evaluate DNA damage in subjects from both locations we determined the levels of bulky DNA adducts in peripheral blood lymphocytes using the (32)P-postlabeling method. Despite higher B[a]P air pollution in the Ostrava region during all sampling periods, the levels of B[a]P-like DNA adducts per 10(8) nucleotides were significantly higher in the Ostrava subjects only in winter 2009 (mean ± SD: 0.21 ± 0.06 versus 0.28 ± 0.08 adducts/10(8) nucleotides, P < 0.001 for Prague and Ostrava subjects, respectively; P < 0.001). During the other two sampling periods, the levels of B[a]P-like DNA adducts were significantly higher in the Prague subjects (P < 0.001). Multivariate analyses conducted among subjects from Ostrava and Prague separately during all sampling periods revealed that exposure to B[a]P and PM2.5 significantly increased levels of B[a]P-like DNA adducts in the Ostrava subjects, but not in subjects from Prague.