Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2022
The comet assay is widely used for quantification of genomic damage in humans. Peripheral blood d... more The comet assay is widely used for quantification of genomic damage in humans. Peripheral blood derived mononuclear cells (PBMCs) are the most often used cell type for this purpose. Since the comet assay can be performed in an enhanced throughput format, it can be applied to large sample collections such as biobanks. The European Prospective Investigation into Cancer and Nutrition (EPIC) study is one of the largest existing prospective cohort studies, and the German Cancer Research Institute (DKFZ) in Heidelberg is a participating center with 25.000 frozen blood samples stored from around 25 years ago, enabling retrospective assessment of disease risk factors. However, experience with decades long frozen samples in the comet assay is so far missing. In Heidelberg, 800 study participants were re-invited twice between 2010 and 2012 to donate further blood samples. Here, we analyzed 299 Heidelberg-EPIC samples, compiled from frozen PBMC and buffy coat preparations selected from the different sampling time points. In addition, 47 frozen PBMC samples from morbidly obese individuals were included. For buffy coat samples, we observed a poor correlation between DNA damage in the same donors assessed at two sampling time points. Additionally, no correlation between DNA damage in buffy coat samples and PBMCs was found. For PBMCs, a good correlation was observed between samples of the same donors at the two time points. DNA damage was not affected by age and smoking status, but high BMI (>30; obesity) was associated with increased DNA damage in PBMCs. There was no indication for a threshold of a certain BMI for increased DNA damage. In conclusion, while 25 year-long stored buffy coat preparations may require adaptation of certain experimental parameters such as cell density and electrophoresis conditions, frozen PBMC biobank samples can be analyzed in the comet assay even after a decade of storage.
Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbat... more Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbate ozone-induced adverse effects on lung function, injury, and inflammation in offspring, and it has been suggested that mitochondrial dysfunction is implicated herein. The aim of this study was to investigate whether a perinatal obesogenic HFD affects ozone-induced changes in offspring pulmonary oxidant status and the molecular control of mitochondrial function. For this purpose, female Long-Evans rats were fed a control diet or HFD before and during gestation, and during lactation, after which the offspring were acutely exposed to filtered air or ozone at a young-adult age (forty days). Directly following this exposure, the offspring lungs were examined for markers related to oxidative stress; oxidative phosphorylation; and mitochondrial fusion, fission, biogenesis, and mitophagy. Acute ozone exposure significantly increased pulmonary oxidant status and upregulated the molecular machine...
Hypoxia is characteristic for a number of pathologies and promotes genetic instability, as exposu... more Hypoxia is characteristic for a number of pathologies and promotes genetic instability, as exposure to low oxygen levels results in an elevated mutation frequency. We have previously shown that activation of the hypoxia responsive transcription factor HIF-1α, in the presence of sufficient oxygen, enhanced mutation frequencies induced by the environmental mutagen benzo[a]pyrene (BaP). Since proper carcinogen metabolism depends on oxygen we examined how varying oxygen levels influenced BaP metabolism by studying its activation and deactivation. The human lung carcinoma cell line A549 was treated with BaP under different oxygen concentrations (20%, 5%, and 0.2%) for 18 hours and alterations in BaP-metabolism were determined. First, we analyzed the BaP induced expression of key metabolic enzymes; expression levels of CYP1A1 and CYP1B1 was higher under hypoxia, while expression of the detoxifying enzymes UGT1A6 and UGT2B7 were significantly reduced by hypoxia. Then, several BaP metabolites in supernatants were determined by HPLC-fluorescence detection. In general, low oxygen levels lead to slower metabolism of BaP leaving more of the parent molecule intact. At the same time, BaP-7,8-dihydrodiol, the pre-cursor metabolite of the reactive metabolite BaP-7,8-dihydroxy-9,10-epoxide (BPDE), was formed in higher concentrations under hypoxia. Finally, under hypoxia DNA adducts accumulated over a period of 168 hours, whereas DNA adducts were efficiently removed under 20% oxygen, eventually leading to 1.6 times higher adduct levels under hypoxic conditions. These data indicate that the metabolism has shifted towards increased activation of BaP instead of detoxification under hypoxic conditions. These data support the idea that modulation of carcinogen metabolism may be an important additional mechanism for the observed HIF1 mediated genetic instability. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4118. doi:1538-7445.AM2012-4118
Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Background: Polycyc... more Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Background: Polycyclic aromatic hydrocarbons (PAHs) play a role in esophageal squamous cell carcinoma in high risk areas where even non-smokers are highly exposed to these compounds. Their early biological effect is the formation of DNA adducts, mediated by phase 1 and 2 pathways and nucleotide excision repair (NER). We aimed at finding a genetic model to explain inter-individual variations in PAH-DNA adduct level among people with similar exposures. Methods: In 111 randomly-selected female non-smokers from the Golestan Cohort Study in Iran, 21 SNPs in 14 genes related to xenobiotic metabolism and 13 SNPs in 9 DNA repair genes were studied (Table). NER capacity was evaluated by a comet assay, and DNA adduct level was measured by 32p-postlabelling. Multivariate regression was used to assess the effects of the number of risk alleles, NER capacity, and environmental exposures on the log-transformed PAH-DNA adduct levels. Models were compared by Akaike's information criterion (AIC). Results: Mean PAH-DNA adduct level was 5.76+3.13 per 108 nucleotides (range: 1.71 - 18.57). The level of PAH-DNA adducts was significantly lower in homozygotes for N-acetyltransferase 2 (NAT2) slow alleles and excision repair cross-complementing (ERCC)-5 T/T genotype, and higher in individuals with myeloperoxidase (MPO) G/G genotype. The sum of risk alleles in these genes had a significant correlation with the log-adduct level (r=0.4, p<0.001). The table shows gene level coefficients for multivariate analysis. The model including environmental exposures, phase 1 SNPs and NER capacity had the best fit (AIC=93.7). NER capacity itself was affected by a polymorphism in the methylenetetrahydrofolate reductase gene. Conclusion: We observed a high level of PAH-DNA adducts with great inter-individual variation, which could be best explained by a combination of environmental factors, number of polymorphisms in phase 1 genes and DNA repair capacity. ![Figure][1] Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2646. doi:1538-7445.AM2012-2646 [1]: pending:yes
Background Benzo [a]pyrene (B[a]P) exposure induces DNA adducts at all stages of spermatogenesis ... more Background Benzo [a]pyrene (B[a]P) exposure induces DNA adducts at all stages of spermatogenesis and in testis, and removal of these lesions is less efficient in nucleotide excision repair deficient Xpc -/- mice than in wild type mice. In this study, we investigated by using microarray technology whether compromised DNA repair in Xpc -/- mice may lead to a transcriptional reaction of the testis to cope with increased levels of B[a]P induced DNA damage. Results Two-Way ANOVA revealed only 4 genes differentially expressed between wild type and Xpc -/- mice, and 984 genes between testes of B[a]P treated and untreated mice irrespective of the mouse genotype. However, the level in which these B[a]P regulated genes are expressed differs between Wt and Xpc -/- mice (p = 0.000000141), and were predominantly involved in the regulation of cell cycle, translation, chromatin structure and spermatogenesis, indicating a general stress response. In addition, analysis of cell cycle phase dependent ...
Gene–environment interactions determine inter-individual variations in nucleotide excision repair... more Gene–environment interactions determine inter-individual variations in nucleotide excision repair (NER) capacity. Oxidative stress was previously found to inhibit NER, thus supplementation with dietary antioxidants could prevent this inhibition, especially in genetically susceptible subjects. To study the effects of genetic polymorphisms in NER-related genes and dietary intake of antioxidants on an individual's NER capacity, lymphocytes of 168 subjects were isolated before and after a 4-week blueberry and apple juice intervention. Twelve genetic polymorphisms in NER genes XPA, XPC, ERCC1, ERCC2, ERCC5, ERCC6 and RAD23B were assessed by multiplex PCR with single base extension. Based on specific genotype combinations, a subset of individuals (n 36) was selected for phenotypical assessment of NER capacity, which was significantly affected by the total sum of low-activity alleles (P = 0·027). The single polymorphism XPA G23A was the strongest predictor of NER capacity (P = 0·002); ...
Studies have suggested a possible role of polycyclic aromatic hydrocarbons (PAHs) in the etiology... more Studies have suggested a possible role of polycyclic aromatic hydrocarbons (PAHs) in the etiology of esophageal cancer in Golestan Province, Iran, where incidence of this cancer is very high. In order to investigate the patterns of non-smoking related exposure to PAHs in Golestan, we conducted a cross-sectional study collecting questionnaire data, genotyping polymorphisms related to PAH metabolism, and measuring levels of 1-hydroxypyrene glucuronide (1-OHPG), a PAH metabolite, in urine samples collected in two seasons from the same group of 111 randomly selected never-smoking women. Beta-coefficients for correlations between 1-OHPG as dependent variable and other variables were calculated using linear regression models. The creatinine-adjusted 1-OHPG levels in both winter and summer samples were approximately 110 μmol/molCr (P for seasonal difference = 0.40). In winter, red meat intake (β = 0.208; P = 0.03), processed meat intake (β = 0.218; P = 0.02), and GSTT1-02 polymorphism (“nu...
Islami, Farhad; Boffetta, Paolo; van Schooten, Frederik J; Strickland, Paul; Phillips, David H; P... more Islami, Farhad; Boffetta, Paolo; van Schooten, Frederik J; Strickland, Paul; Phillips, David H; Pourshams, Akram; Fazel-Tabar Malekshah, Akbar; Godschalk, Roger; Jafari, Elham; Etemadi, Arash; +6 more... Abubaker, Salahadin; Kamangar, Farin; Straif, Kurt; Møller, Henrik; Schüz, Joachim; Malekzadeh, Reza; (2012) Exposure to Polycyclic Aromatic Hydrocarbons Among Never Smokers in Golestan Province, Iran, an Area of High Incidence of Esophageal Cancer a Cross-Sectional Study with Repeated Measurement of Urinary 1-OHPG in Two Seasons. Front Oncol, 2. 14-. ISSN 2234943X DOI: https://doi.org/10.3389/fonc.2012.00014 Downloaded from: http://researchonline.lshtm.ac.uk/id/eprint/56926/
The comet assay or single cell gel electrophoresis, is the most common method used to measure str... more The comet assay or single cell gel electrophoresis, is the most common method used to measure strand breaks and a variety of other DNA lesions in human populations. To estimate the risk of overall mortality, mortality by cause, and cancer incidence associated to DNA damage, a cohort of 2,403 healthy individuals (25,978 person-years) screened in 16 laboratories using the comet assay between 1996 and 2016 was followed-up. Kaplan–Meier analysis indicated a worse overall survival in the medium and high tertile of DNA damage (p
Molecular mechanisms underlying Hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC)... more Molecular mechanisms underlying Hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) pathogenesis are still unclear. Therefore, we analyzed the levels of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and other oxidative lesions at codon 176 of the p53 gene, as well as the generation of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M1dG), in a cohort of HCV-related HCC patients from Italy. Detection of 8-oxodG and 5-hydroxycytosine (5-OHC) was performed by ligation mediated-polymerase chain reaction assay, whereas the levels of M1dG were measured by chromatography and mass-spectrometry. Results indicated a significant 130% excess of 8-oxodG at –TGC– position of p53 codon 176 in HCV-HCC cases as compared to controls, after correction for age and gender, whereas a not significant increment of 5-OHC at –TGC– position was found. Then, regression models showed an 87% significant excess of M1dG in HCV-HCC cases relative to controls. Our ...
Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2022
The comet assay is widely used for quantification of genomic damage in humans. Peripheral blood d... more The comet assay is widely used for quantification of genomic damage in humans. Peripheral blood derived mononuclear cells (PBMCs) are the most often used cell type for this purpose. Since the comet assay can be performed in an enhanced throughput format, it can be applied to large sample collections such as biobanks. The European Prospective Investigation into Cancer and Nutrition (EPIC) study is one of the largest existing prospective cohort studies, and the German Cancer Research Institute (DKFZ) in Heidelberg is a participating center with 25.000 frozen blood samples stored from around 25 years ago, enabling retrospective assessment of disease risk factors. However, experience with decades long frozen samples in the comet assay is so far missing. In Heidelberg, 800 study participants were re-invited twice between 2010 and 2012 to donate further blood samples. Here, we analyzed 299 Heidelberg-EPIC samples, compiled from frozen PBMC and buffy coat preparations selected from the different sampling time points. In addition, 47 frozen PBMC samples from morbidly obese individuals were included. For buffy coat samples, we observed a poor correlation between DNA damage in the same donors assessed at two sampling time points. Additionally, no correlation between DNA damage in buffy coat samples and PBMCs was found. For PBMCs, a good correlation was observed between samples of the same donors at the two time points. DNA damage was not affected by age and smoking status, but high BMI (>30; obesity) was associated with increased DNA damage in PBMCs. There was no indication for a threshold of a certain BMI for increased DNA damage. In conclusion, while 25 year-long stored buffy coat preparations may require adaptation of certain experimental parameters such as cell density and electrophoresis conditions, frozen PBMC biobank samples can be analyzed in the comet assay even after a decade of storage.
Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbat... more Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbate ozone-induced adverse effects on lung function, injury, and inflammation in offspring, and it has been suggested that mitochondrial dysfunction is implicated herein. The aim of this study was to investigate whether a perinatal obesogenic HFD affects ozone-induced changes in offspring pulmonary oxidant status and the molecular control of mitochondrial function. For this purpose, female Long-Evans rats were fed a control diet or HFD before and during gestation, and during lactation, after which the offspring were acutely exposed to filtered air or ozone at a young-adult age (forty days). Directly following this exposure, the offspring lungs were examined for markers related to oxidative stress; oxidative phosphorylation; and mitochondrial fusion, fission, biogenesis, and mitophagy. Acute ozone exposure significantly increased pulmonary oxidant status and upregulated the molecular machine...
Hypoxia is characteristic for a number of pathologies and promotes genetic instability, as exposu... more Hypoxia is characteristic for a number of pathologies and promotes genetic instability, as exposure to low oxygen levels results in an elevated mutation frequency. We have previously shown that activation of the hypoxia responsive transcription factor HIF-1α, in the presence of sufficient oxygen, enhanced mutation frequencies induced by the environmental mutagen benzo[a]pyrene (BaP). Since proper carcinogen metabolism depends on oxygen we examined how varying oxygen levels influenced BaP metabolism by studying its activation and deactivation. The human lung carcinoma cell line A549 was treated with BaP under different oxygen concentrations (20%, 5%, and 0.2%) for 18 hours and alterations in BaP-metabolism were determined. First, we analyzed the BaP induced expression of key metabolic enzymes; expression levels of CYP1A1 and CYP1B1 was higher under hypoxia, while expression of the detoxifying enzymes UGT1A6 and UGT2B7 were significantly reduced by hypoxia. Then, several BaP metabolites in supernatants were determined by HPLC-fluorescence detection. In general, low oxygen levels lead to slower metabolism of BaP leaving more of the parent molecule intact. At the same time, BaP-7,8-dihydrodiol, the pre-cursor metabolite of the reactive metabolite BaP-7,8-dihydroxy-9,10-epoxide (BPDE), was formed in higher concentrations under hypoxia. Finally, under hypoxia DNA adducts accumulated over a period of 168 hours, whereas DNA adducts were efficiently removed under 20% oxygen, eventually leading to 1.6 times higher adduct levels under hypoxic conditions. These data indicate that the metabolism has shifted towards increased activation of BaP instead of detoxification under hypoxic conditions. These data support the idea that modulation of carcinogen metabolism may be an important additional mechanism for the observed HIF1 mediated genetic instability. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4118. doi:1538-7445.AM2012-4118
Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Background: Polycyc... more Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Background: Polycyclic aromatic hydrocarbons (PAHs) play a role in esophageal squamous cell carcinoma in high risk areas where even non-smokers are highly exposed to these compounds. Their early biological effect is the formation of DNA adducts, mediated by phase 1 and 2 pathways and nucleotide excision repair (NER). We aimed at finding a genetic model to explain inter-individual variations in PAH-DNA adduct level among people with similar exposures. Methods: In 111 randomly-selected female non-smokers from the Golestan Cohort Study in Iran, 21 SNPs in 14 genes related to xenobiotic metabolism and 13 SNPs in 9 DNA repair genes were studied (Table). NER capacity was evaluated by a comet assay, and DNA adduct level was measured by 32p-postlabelling. Multivariate regression was used to assess the effects of the number of risk alleles, NER capacity, and environmental exposures on the log-transformed PAH-DNA adduct levels. Models were compared by Akaike's information criterion (AIC). Results: Mean PAH-DNA adduct level was 5.76+3.13 per 108 nucleotides (range: 1.71 - 18.57). The level of PAH-DNA adducts was significantly lower in homozygotes for N-acetyltransferase 2 (NAT2) slow alleles and excision repair cross-complementing (ERCC)-5 T/T genotype, and higher in individuals with myeloperoxidase (MPO) G/G genotype. The sum of risk alleles in these genes had a significant correlation with the log-adduct level (r=0.4, p<0.001). The table shows gene level coefficients for multivariate analysis. The model including environmental exposures, phase 1 SNPs and NER capacity had the best fit (AIC=93.7). NER capacity itself was affected by a polymorphism in the methylenetetrahydrofolate reductase gene. Conclusion: We observed a high level of PAH-DNA adducts with great inter-individual variation, which could be best explained by a combination of environmental factors, number of polymorphisms in phase 1 genes and DNA repair capacity. ![Figure][1] Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2646. doi:1538-7445.AM2012-2646 [1]: pending:yes
Background Benzo [a]pyrene (B[a]P) exposure induces DNA adducts at all stages of spermatogenesis ... more Background Benzo [a]pyrene (B[a]P) exposure induces DNA adducts at all stages of spermatogenesis and in testis, and removal of these lesions is less efficient in nucleotide excision repair deficient Xpc -/- mice than in wild type mice. In this study, we investigated by using microarray technology whether compromised DNA repair in Xpc -/- mice may lead to a transcriptional reaction of the testis to cope with increased levels of B[a]P induced DNA damage. Results Two-Way ANOVA revealed only 4 genes differentially expressed between wild type and Xpc -/- mice, and 984 genes between testes of B[a]P treated and untreated mice irrespective of the mouse genotype. However, the level in which these B[a]P regulated genes are expressed differs between Wt and Xpc -/- mice (p = 0.000000141), and were predominantly involved in the regulation of cell cycle, translation, chromatin structure and spermatogenesis, indicating a general stress response. In addition, analysis of cell cycle phase dependent ...
Gene–environment interactions determine inter-individual variations in nucleotide excision repair... more Gene–environment interactions determine inter-individual variations in nucleotide excision repair (NER) capacity. Oxidative stress was previously found to inhibit NER, thus supplementation with dietary antioxidants could prevent this inhibition, especially in genetically susceptible subjects. To study the effects of genetic polymorphisms in NER-related genes and dietary intake of antioxidants on an individual's NER capacity, lymphocytes of 168 subjects were isolated before and after a 4-week blueberry and apple juice intervention. Twelve genetic polymorphisms in NER genes XPA, XPC, ERCC1, ERCC2, ERCC5, ERCC6 and RAD23B were assessed by multiplex PCR with single base extension. Based on specific genotype combinations, a subset of individuals (n 36) was selected for phenotypical assessment of NER capacity, which was significantly affected by the total sum of low-activity alleles (P = 0·027). The single polymorphism XPA G23A was the strongest predictor of NER capacity (P = 0·002); ...
Studies have suggested a possible role of polycyclic aromatic hydrocarbons (PAHs) in the etiology... more Studies have suggested a possible role of polycyclic aromatic hydrocarbons (PAHs) in the etiology of esophageal cancer in Golestan Province, Iran, where incidence of this cancer is very high. In order to investigate the patterns of non-smoking related exposure to PAHs in Golestan, we conducted a cross-sectional study collecting questionnaire data, genotyping polymorphisms related to PAH metabolism, and measuring levels of 1-hydroxypyrene glucuronide (1-OHPG), a PAH metabolite, in urine samples collected in two seasons from the same group of 111 randomly selected never-smoking women. Beta-coefficients for correlations between 1-OHPG as dependent variable and other variables were calculated using linear regression models. The creatinine-adjusted 1-OHPG levels in both winter and summer samples were approximately 110 μmol/molCr (P for seasonal difference = 0.40). In winter, red meat intake (β = 0.208; P = 0.03), processed meat intake (β = 0.218; P = 0.02), and GSTT1-02 polymorphism (“nu...
Islami, Farhad; Boffetta, Paolo; van Schooten, Frederik J; Strickland, Paul; Phillips, David H; P... more Islami, Farhad; Boffetta, Paolo; van Schooten, Frederik J; Strickland, Paul; Phillips, David H; Pourshams, Akram; Fazel-Tabar Malekshah, Akbar; Godschalk, Roger; Jafari, Elham; Etemadi, Arash; +6 more... Abubaker, Salahadin; Kamangar, Farin; Straif, Kurt; Møller, Henrik; Schüz, Joachim; Malekzadeh, Reza; (2012) Exposure to Polycyclic Aromatic Hydrocarbons Among Never Smokers in Golestan Province, Iran, an Area of High Incidence of Esophageal Cancer a Cross-Sectional Study with Repeated Measurement of Urinary 1-OHPG in Two Seasons. Front Oncol, 2. 14-. ISSN 2234943X DOI: https://doi.org/10.3389/fonc.2012.00014 Downloaded from: http://researchonline.lshtm.ac.uk/id/eprint/56926/
The comet assay or single cell gel electrophoresis, is the most common method used to measure str... more The comet assay or single cell gel electrophoresis, is the most common method used to measure strand breaks and a variety of other DNA lesions in human populations. To estimate the risk of overall mortality, mortality by cause, and cancer incidence associated to DNA damage, a cohort of 2,403 healthy individuals (25,978 person-years) screened in 16 laboratories using the comet assay between 1996 and 2016 was followed-up. Kaplan–Meier analysis indicated a worse overall survival in the medium and high tertile of DNA damage (p
Molecular mechanisms underlying Hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC)... more Molecular mechanisms underlying Hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) pathogenesis are still unclear. Therefore, we analyzed the levels of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and other oxidative lesions at codon 176 of the p53 gene, as well as the generation of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M1dG), in a cohort of HCV-related HCC patients from Italy. Detection of 8-oxodG and 5-hydroxycytosine (5-OHC) was performed by ligation mediated-polymerase chain reaction assay, whereas the levels of M1dG were measured by chromatography and mass-spectrometry. Results indicated a significant 130% excess of 8-oxodG at –TGC– position of p53 codon 176 in HCV-HCC cases as compared to controls, after correction for age and gender, whereas a not significant increment of 5-OHC at –TGC– position was found. Then, regression models showed an 87% significant excess of M1dG in HCV-HCC cases relative to controls. Our ...
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Papers by Roger Godschalk