8-hydroxy-2--deoxyguanosine and Neoplasms

Oxidative stress is associated with the development and progression of numerous diseases. However, targeting oxidative stress has not been established in the clinical management of any disease. Several methods and markers are available to measure oxidative stress, including direct measurement of free radicals, antioxidants, redox balance, and oxidative modifications of cellular macromolecules. Oxidatively generated nucleic acid modifications have attracted much interest due to the pre-mutagenic oxidative modification of DNA into 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), associated with cancer development. During the last decade, the perception of RNA has changed from that of a 'silent messenger' to an 'active contributor', and, parallelly oxidatively generated RNA modifications measured as 8-oxo-7,8-dihydro-guanosine (8-oxoGuo), has been demonstrated as a prognostic factor for all-caused and cardiovascular related mortality in patients with type 2 diabetes. Several attempts have been made to modify the amount of oxidative nucleic acid modifications. Thus, this review aims to introduce researchers to the measurement of oxidatively generated nucleic acid modifications as well as critically review previous attempts and provide future directions for targeting oxidatively generated nucleic acid modifications.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers; DNA Damage; Humans; Neoplasms; Nucleic Acids; Oxidative Stress

The oxidized guanine nucleosides, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), derived from DNA and RNA, respectively, were used to investigate the importance of oxidative stress to nucleic acids in vivo. High urinary excretion of 8-oxodG is associated with cancer development, whereas high urinary excretion of 8-oxoGuo is associated with mortality in type 2 diabetes. Like creatinine, these small water-soluble molecules are not reabsorbed in the kidney. Therefore, 8-oxo nucleoside/creatinine reciprocal concentration ratios are identical in plasma and urine. The total amount of 8-oxo guanine nucleosides excreted by the kidneys is the product of plasma concentration and glomerular filtration rate.. With relevant equations and an estimated glomerular filtration rate, the 24-h urinary excretion of 8-oxodG and 8-oxoGuo was calculated in 2679 subjects with type 2 diabetes, displaying good correlation with the measured urinary 8-oxo nucleoside/creatinine ratio: DNA oxidation r = 0.86 and RNA oxidation r = 0.84 (p < 0.05 for both).. Survival analyses based on the quartiles of the 8-oxodG/creatinine ratio and the quartiles of calculated 24-h urinary excretion rate of the 2679 subjects gave similar hazard ratio estimates for death due to all causes. This finding was similar for the 8-oxoGuo hazard ratio estimates.. This study shows that oxidatively generated modifications to DNA and RNA in vivo can be measured using 1) a spot urine sample, normalized to urinary creatinine, 2) 24-h urine, or 3) a single plasma sample based on concentrations of 8-oxo nucleoside and creatinine and glomerular filtration rate.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers; DNA Damage; Humans; Neoplasms; Nucleic Acids; Oxidative Stress; Proportional Hazards Models

High level of reactive oxygen species (ROS) has been detected in almost all cancers, which make it become one of the best-characterized phenotypes in cancers. Though ROS plays an important role in tumors, the degree of oxidative stress can be better evaluated by assessing stable metabolites of oxidative reactions because of its high instability. 8-hydroxy-2'-deoxyguanosine (8-OHdG), a product of oxidative damage to 2'-deoxyguanosine, is known as a useful marker for assessing oxidative DNA damage and has been a feature of carcinogenesis in several researches. But the exact prognostic value of 8-OHdG expression in patients with cancer is still unclear.. A comprehensive search was performed in PubMed, Web of Science, EMBASE. Eligible studies were included based on defined exclusion and inclusion criteria to perform a meta-analysis. STATA 14.0 was used to estimate pooled hazard ratios (HRs) with 95% confidence interval (95% CI), the heterogeneity among studies and publication bias to judge the prognostic value.. A total of 2121 patients from 21 eligible studies were included in the meta-analysis. A significant association was found between elevated 8-OHdG expression and poor OS (overall survival) in cancer patients (pooled HR 1.921, 95% CI: 1.437-2.570); In the subgroup analysis, race of sample, cancer types, detection method of 8-OHdG, sample classification, detection location of 8-OHdG and paper quality (score more or less than 7) did not alter the association between 8-OHdG expression and cancer prognosis. Furthermore, 8-OHdG expression was an independent prognostic marker for overall survival in patients with cancer (pooled HR 2.110, 95% CI: 1.482-3.005) using Cox multivariate analyses.. This meta-analysis found that highly expressed 8-OHdG in tumor tissues may be a predictor of prognosis in most solid tumors. However, especially in breast cancer, low 8-OHdG expression is associated with poor prognosis, which is partly because of the increased antioxidant mechanisms in breast cancer tissues. This study demonstrates for the first time that 8-OHdG expression is associated with the prognosis of cancer patients. In the future, whether the expression level of 8-OHdG can be used as a biomarker for the prognosis of all human cancers requires more research.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers, Tumor; Disease-Free Survival; DNA Damage; Humans; Neoplasms; Oxidative Stress; Prognosis; Proportional Hazards Models; Reactive Oxygen Species

Inflammation can be induced by chronic infection, inflammatory diseases and physicochemical factors. Chronic inflammation is estimated to contribute to approximately 25% of human cancers. Under inflammatory conditions, inflammatory and epithelial cells release reactive oxygen (ROS) and nitrogen species (RNS), which are capable of causing DNA damage, including the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine and 8-nitroguanine. We reported that 8-nitroguanine was clearly formed at the sites of cancer induced by infectious agents including

Topics: 8-Hydroxy-2'-Deoxyguanosine; Carcinogenesis; Deoxyguanosine; DNA Damage; Guanine; Humans; Inflammation; Mutation; Neoplasms; Nitric Oxide Synthase Type II; Reactive Nitrogen Species; Reactive Oxygen Species; Tumor Hypoxia

Most arylamines are pro-carcinogens, and require metabolic activation to yield ultimate carcinogen metabolites. O-Acetylation of the N-hydroxy form of an arylamine yields an acetoxyarylamine, which can form a highly reactive arylnitrenium ion, the ultimate metabolite responsible for DNA adduct formation. However, we demonstrate here that the N-hydroxy and nitroso forms of arylamines can also induce DNA damage, including 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodG) lesions, via reactive oxygen species formation. The N-hydroxy and nitroso derivatives of carcinogenic arylamines may contribute to the carcinogenic process through H2O2 formation. N-Hydroxy derivatives induce metal-mediated DNA damage, with remarkable enhancement by NADH. Nitroso derivatives induce NADH-dependent DNA damage in the presence of metal ions. Hydroxy derivatives of arylamines formed by enzymatic hydroxylation or as o- or p-aminophenols can also induce DNA damage in the presence of metal ions. The autoxidation of o-phenylenediamine and several arylamine metabolites is accelerated in the presence of SOD or manganese, resulting in the enhancement of metal-mediated DNA damage. The oxidative DNA damage induced by arylamine compounds may participate in chemical carcinogenesis, in addition to DNA adduct formation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aminobiphenyl Compounds; Animals; Benzidines; Carcinogens; Deoxyguanosine; DNA Adducts; DNA Damage; Humans; Neoplasms; Oxidation-Reduction

Oxidative stress refers to the imbalance between the generation of reactive oxygen species (ROS) and their scavenging by the inherent antioxidant defenses of the cell. The abnormal accumulation of ROS is the underlying pathology in a variety of human diseases such as neurodegenerative phenomena, inflammatory diseases, metabolic disorders, and cancer. The mechanism by which abnormal accumulation of ROS contributes to pathological conditions involves damage or oxidative modification of biomolecules, such as nucleotides, lipids, and proteins. One of the most common targets of ROS is DNA, modifications of which have been associated with cellular transformation and genome instability. There are a number of experimental strategies to assess oxidative modification of DNA bases, such as chromatography-based assays and indirect immunofluorescence. While the former provide quantitative assessment of oxidative modification, the latter is a much simpler assay for qualitative determination of DNA base modification in very small sample sizes. Here, we present a brief background of the various methodologies for the assessment of a specific oxidative DNA modification, 8oxodG, and present a more detailed account of the indirect immunofluorescence assay.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Antibodies, Monoclonal; Biomarkers; Cell Line, Tumor; Colorectal Neoplasms; Deoxyguanosine; DNA; DNA Damage; Fluorescent Antibody Technique; Humans; Hydrogen Peroxide; Microscopy, Confocal; Neoplasms; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species

Oxidative damage DNA is aninevitable, natural consequence of cellular metabolism resulting from formation of reactive oxygen species (ROS) including free oxygen radicals. However, the level ofthe damage may increase under conditions of oxidative stress, arising from exposure to a variety of physical or chemical insults. In this review we present the mechanisms by which oxidative damage to DNA may lead to pathological processes involved in the development of cancer, cardiovascular diseases and ageing. Furthermore, we describe mechanisms of DNA repair which play a key role in maintaining cellular function upon DNA insult. Among over 20 identified and described oxidative modifications of DNA bases only one derivative, namely 8-oxo-2'-deoxyguanosine (8-oxo-dG), has become a subject of intense research. Therefore, we are presenting methods of 8-oxo-dG detection as a marker of oxidatively damaged DNA.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Autoimmune Diseases; Biomarkers; Deoxyguanosine; DNA Damage; DNA Repair; Hepatitis B; HIV Infections; Humans; Inflammation; Mass Spectrometry; Neoplasms; Oxidative Stress; Reactive Oxygen Species

There is extensive experimental evidence that oxidative damage permanently occurs to lipids of cellular membranes, proteins, and DNA. In nuclear and mitochondrial DNA, 8-hydroxy-2' -deoxyguanosine (8-OHdG) or 8-oxo-7,8-dihydro-2' -deoxyguanosine (8-oxodG) is one of the predominant forms of free radical-induced oxidative lesions, and has therefore been widely used as a biomarker for oxidative stress and carcinogenesis. Studies showed that urinary 8-OHdG is a good biomarker for risk assessment of various cancers and degenerative diseases. The most widely used method of quantitative analysis is high-performance liquid chromatography (HPLC) with electrochemical detection (EC), gas chromatography-mass spectrometry (GC-MS), and HPLC tandem mass spectrometry. In order to resolve the methodological problems encountered in measuring quantitatively 8-OHdG, the European Standards Committee for Oxidative DNA Damage was set up in 1997 to resolve the artifactual oxidation problems during the procedures of isolation and purification of oxidative DNA products. The biomarker 8-OHdG or 8-oxodG has been a pivotal marker for measuring the effect of endogenous oxidative damage to DNA and as a factor of initiation and promotion of carcinogenesis. The biomarker has been used to estimate the DNA damage in humans after exposure to cancer-causing agents, such as tobacco smoke, asbestos fibers, heavy metals, and polycyclic aromatic hydrocarbons. In recent years, 8-OHdG has been used widely in many studies not only as a biomarker for the measurement of endogenous oxidative DNA damage but also as a risk factor for many diseases including cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers; Carcinogens, Environmental; Cocarcinogenesis; Deoxyguanosine; DNA Damage; Environmental Exposure; Humans; Mutagenesis; Neoplasms; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species; Risk Factors

Oxidative damage to DNA is regarded as an important step in carcinogenesis. These lesions may arise as a consequence of exposure to xenobiotics, but are also generated as a consequence of endogenous generation of oxidizing compounds. Measurements of oxidative damage to guanines, such as 8-oxo-7, 8-dihydroguanine (8-oxodG) are increasingly being regarded as reliable biomarkers of oxidative stress and they may have a predictive value of cancer risk, although this needs to be established independently in several cohort studies. A survey of intervention studies of the ingestion of antioxidant-containing foods or tablets of antioxidants indicate that about one-third of the studies reported a protective effect in terms of lower levels of oxidative damage to DNA in white blood cells or decreased urinary excretion of 8-oxodG. Although firm conclusions cannot be reached, there appears to be links between ingestion of antioxidants, oxidative damage to DNA, and risk of cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Antioxidants; Biomarkers, Tumor; Comet Assay; Deoxyguanosine; Diet; DNA Damage; DNA Repair; Humans; Neoplasms; Nutritional Physiological Phenomena; Oxidation-Reduction; Oxidative Stress; Predictive Value of Tests; Reactive Oxygen Species; Risk Factors; Vitamins

Reactive oxygen species (ROS) produced either endogenously or exogenously can attack lipid, protein and nucleic acid simultaneously in the living cells. In nuclear and mitochondrial DNA, 8-hydroxydeoxyguanosine (8-OHdG), an oxidized nucleoside of DNA, is the most frequently detected and studied DNA lesion. Upon DNA repair, 8-OHdG is excreted in the urine. Numerous evidences have indicated that urinary 8-OHdG not only is a biomarker of generalized, cellular oxidative stress but might also be a risk factor for cancer, atherosclerosis and diabetes. For example, elevated level of urinary 8-OHdG has been detected in patients with various cancers. In human atherosclerotic plaques, there were increased amounts of oxidatively modified DNA and 8-OHdG. Elevated urinary 8-OHdG and leukocyte DNA were also detected in diabetic patients with hyperglycemia, and the level of urinary 8-OHdG in diabetes correlated with the severity of diabetic nephropathy and retinopathy. We have discussed various methods for determining 8-OHdG in the tissue and urine, including HPLC with and without extraction, and ELISA. Using the ELISA we developed, we found that the normal range of urinary 8-OHdG for females was 43.9 +/- 42.1 ng/mg creatinine and 29.6 +/- 24.5 ng/mg creatinine for males, respectively. We found that the normal value between females and males is significantly different (p < 0.001).

Topics: 8-Hydroxy-2'-Deoxyguanosine; Arteriosclerosis; Deoxyguanosine; Diabetes Mellitus; DNA Damage; Humans; Neoplasms; Oxidative Stress; Risk Factors

Adducts arise from the chemical modification of bases in DNA or amino acids in proteins by toxic chemicals. Many chemicals known to be carcinogenic in humans have been shown to form adducts or to cause oxidative damage to genomic DNA in model systems. Biomarkers of carcinogenesis reflect biological events that take place between exposure to external or endogenous carcinogens and the subsequent development of cancer. Therapeutic intervention for the purpose of cancer chemoprevention may modify these biomarkers. In this article, the potential efficacy of DNA adducts as biomarkers of carcinogenesis and chemoprevention is discussed using criteria defined for phases of biomarker development. The sensitivity of adduct detection in histologically normal tissue offers opportunities for the early detection of carcinogenesis. Extensive evidence for aflatoxin B(1) adducts as biomarkers of risk and progression of hepatic carcinogenesis and for oxidative DNA adducts as biomarkers of the development of prostate carcinogenesis is reviewed together with the clinical trials measuring these adducts as biomarkers of the efficacy of chemoprevention. Favorable modification of oxidative DNA adducts by dietary intervention and chemoprevention has been demonstrated in preclinical and clinical studies. Protein adducts and DNA adducts in blood constituents or urine may act as useful surrogates for the target organ. Additional information regarding reliability, reproducibility, specificity, and confounding variables are required at the clinical level to validate adducts as suitable biomarkers of chemoprevention. "We do not administer antihypertensive drugs to patients in clinical trials without checking their blood pressure, so why should we give antioxidants without checking that they have decreased oxidant status.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aflatoxin B1; Anticarcinogenic Agents; Antioxidants; Biomarkers, Tumor; Carcinogens; Carcinoma, Hepatocellular; Cell Transformation, Neoplastic; Clinical Trials as Topic; Deoxyguanosine; Diet; DNA; DNA Adducts; DNA Damage; DNA Repair; Humans; Immunochemistry; Male; Mass Spectrometry; Models, Chemical; Neoplasms; Oxidative Stress; Oxygen; Prostatic Neoplasms; Proteins; Risk; Sensitivity and Specificity

Free radicals and other reactive species are constantly generated in vivo and cause oxidative damage to DNA at a rate that is probably a significant contributor to the age-related development of cancer. Agents that decrease oxidative DNA damage should thus decrease the risk of cancer development. That is, oxidative DNA damage is a "biomarker" for identifying persons at risk (for dietary or genetic reasons, or both) of developing cancer and for suggesting how the diets of these persons could be modified to decrease that risk. This biomarker concept presupposes that we can measure oxidative damage accurately in DNA from relevant tissues. Little information is available on whether oxidative DNA damage in blood cells mirrors such damage in tissues at risk of cancer development. Measurement of 8-hydroxylated guanine (eg, as 8-hydroxy-2'-deoxyguanosine; 8OHdG) is the commonest method of assessing DNA damage, but there is no consensus on what the true levels are in human DNA. If the lowest levels reported are correct, 8OHdG may be only a minor product of oxidative DNA damage. Indeed, 8OHdG may be difficult to measure because of the ease with which it is formed artifactually during isolation, hydrolysis, and analysis of DNA. Mass spectrometry can accurately measure a wide spectrum of DNA base damage products, but the development of liquid chromatography-mass spectrometry techniques and improved DNA hydrolysis procedures is urgently required. The available evidence suggests that in Western populations, intake of certain fruit and vegetables can decrease oxidative DNA damage, whereas ascorbate, vitamin E, and beta-carotene cannot.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers, Tumor; Deoxyguanosine; DNA; DNA Damage; Humans; Neoplasms; Nutritional Physiological Phenomena; Oxidative Stress

8-hydroxy-2'-deoxyguanosine (8-OH-dG) was first reported in 1984 as a major form of oxidative DNA damage product by heated sugar, Fenton-type reagents and X-irradiation in vitro. 8-OH-dG has been detected in cellular DNA using an HPLC-ECD method in many laboratories. Analyses of 8-OH-dG in animal organ DNA after the administration of oxygen radical-forming chemicals will be useful for assessments of their carcinogenic risk. Its analysis in human leucocyte DNA and in urine is a new approach to the assessment of an individual's cancer risk due to oxidative stress. The increase of the 8-OH-dG level in the cellular DNA, detected by HPLC-ECD method, was supported by its immunochemical detection and its enhanced repair activity. The validity of the general use of 8-OH-dG as a marker of cellular oxidative stress is discussed.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Biomarkers; Carcinogens; Deoxyguanosine; DNA Damage; DNA Repair; Humans; Neoplasms; Oxidative Stress; Reproducibility of Results

In living cells reactive oxygen species (ROS) are formed continuously as a consequence of metabolic and other biochemical reactions as well as external factors. Some ROS have important physiological functions. Thus, antioxidant defense systems cannot provide complete protection from noxious effects of ROS. These include oxidative damage to DNA, which experimental studies in animals and in vitro have suggested are an important factor in carcinogenesis. Despite extensive repair oxidatively modified DNA is abundant in human tissues, in particular in tumors, i.e., in terms of 1-200 modified nucleosides per 10(5) intact nucleosides. The damaged nucleosides accumulate with age in both nuclear and mitochondrial DNA. The products of repair of these lesions are excreted into the urine in amounts corresponding to a damage rate of up to 10(4) modifications in each cell every day. The most abundant of these lesions, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), is also the most mutagenic, resulting in GT transversions which are frequently found in tumor relevant genes. A series of other oxidative modifications of base and sugar residues occur frequently in DNA, but they are less well studied and their biological significance less apparent. The biomarkers for study of oxidative DNA damage in humans include urinary excretion of oxidized nucleosides and bases as repair products and modifications in DNA isolated from target tissue or surrogate cells, such as lymphocytes. These biomarkers reflect the rate of damage and the balance between the damage and repair rate, respectively. By means of biomarkers a number of important factors have been studied in humans. Ionizing radiation, a carcinogenic and pure source of ROS, induced both urinary and leukocyte biomarkers of oxidative DNA damage. Tobacco smoking, another carcinogenic source of ROS, increased the oxidative DNA damage rate by 35-50% estimated from the urinary excretion of 8-oxodG, and the level of 8-oxodG in leukocytes by 20-50%. The main endogenous source of ROS, the oxygen consumption, showed a close correlation with the 8-oxodG excretion rate although moderate exercise appeared to have no immediate effect. So far, cross-sectional study of diet composition and intervention studies, including energy restriction and antioxidant supplements, have generally failed to show an influence on the oxidative DNA modification. However, a diet rich of Brussels sprouts reduced the oxidative DNA damage rate, estimated by the ur

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Animals; Antioxidants; Biomarkers; Carcinogens, Environmental; Cell Transformation, Neoplastic; Cocarcinogenesis; Cross-Sectional Studies; Deoxyguanosine; Diet; DNA Damage; DNA Repair; Female; Humans; Male; Middle Aged; Mutagenesis; Neoplasms; Nucleosides; Oxidation-Reduction; Oxidative Stress; Prospective Studies; Reactive Oxygen Species; Risk Factors; Smoking

On the basis of our recent investigations by a DNA sequencing technique, mechanisms of photoinduced DNA damage in the presence of various endogenous molecules are summarized with special reference to UV carcinogenesis. In particular, riboflavin and pterin derivatives have been shown to induce DNA damage, mainly 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodG) formation, specifically at the 5' site of 5'-GG-3' sequences through electron transfer reaction. The involvement of 8-oxodG formation in ras mutation is discussed. In addition, recent works concerning the mechanism of photodynamic therapy and the properties of photoactivatable DNA-cleaving molecules are described.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Deoxyguanosine; DNA Damage; Electron Transport; Humans; Mutation; Neoplasms; Photochemotherapy; Pterins; ras Proteins; Riboflavin; Sequence Analysis, DNA; Ultraviolet Rays

DNA of cancers such as renal cell carcinoma and mammary invasive ductal carcinoma, is persistently exposed to more oxidative stress than that of adjacent normal tissue. We suggest that the concept of 'persistent oxidative stress in cancer' may open up a new research area, explaining part of the characteristic tumor biology of cancer such as activated transcription factors and proto-oncogenes, genomic instability, chemotherapy-resistance, invasion and metastasis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Deoxyguanosine; DNA, Neoplasm; Humans; Models, Biological; Neoplasms; Oxidative Stress; Reactive Oxygen Species

Progress in identifying the important endogenous processes damaging DNA and developing methods to assay this damage in individuals is presented. This approach may aid studies on modulation of cancer and aging. The endogenous background level of oxidant-induced DNA damage in vivo has been assayed by measuring 8-hydroxydeoxyguanosine (oh8dG), thymine glycol and thymidine glycol in urine and oh8dG in DNA. oh8dG is one of about 20 adducts found on oxidizing DNA, e.g., by radiation. The level of oxidative DNA damage as measured by oh8dG in normal rat liver is shown to be extensive, especially in mtDNA (1/130,000 bases in nuclear DNA and 1/8,000 bases in mitochondrial DNA). We also discuss three hitherto unrecognized antioxidants in man.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Animals; Deoxyguanosine; DNA Damage; Humans; Neoplasms; Oxidation-Reduction

DNA is constantly exposed to reactive oxygen species (ROS), spontaneously arising during the normal oxygen metabolism. ROS may result in temporary as well as permanent modifications in various cellular components such as lipids, proteins and DNA, which may have deleterious consequences. Demonstrating that a dietary supplementation of antioxidants can reduce oxidative DNA damage may provide evidence for the value of such supplementation in prevention of cancer and age related diseases.. The present study was conducted to address whether tomato juice protects against ROS induced by extensive physical exercise in untrained individuals. As a marker of oxidative stress, serum levels of 8-oxodG were monitored using a modified ELISA. An intervention was performed involving 15 untrained healthy subjects who performed a 20 min physical exercise at 80% of maximum pulse using an ergometer bicycle. Blood samples were taken before and one hour after the exercise. The procedure was repeated after 5 weeks with a daily intake of 150 ml tomato juice and followed by a 5 weeks wash-out period and another 5 weeks with a daily intake of tomato juice. The results indicated that a daily intake of tomato juice, equal to 15 mg lycopene per day, for 5 weeks significantly reduced the serum levels of 8-oxodG after an extensive physical exercise.. These data strongly suggest that tomato juice has a potential antioxidant effect and may reduce the elevated level of ROS induced by oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Antioxidants; Beverages; Biomarkers; Carotenoids; Deoxyguanosine; DNA Damage; Enzyme-Linked Immunosorbent Assay; Exercise Test; Female; Fruit; Humans; Lycopene; Male; Motor Activity; Neoplasms; Oxidative Stress; Solanum lycopersicum; Young Adult

High consumption of olive oil in the Mediterranean diet has been suggested to protect DNA against oxidative damage and to reduce cancer incidence. We investigated the impact of the phenolic compounds in olive oil, and the oil proper, on DNA and RNA oxidation in North, Central, and South European populations. In a multicenter, double-blind, randomized, controlled crossover intervention trial, the effect of olive oil phenolic content on urinary oxidation products of guanine (8-oxo-guanine, 8-oxo-guanosine and 8-oxo-deoxyguanosine) was investigated. Twenty-five milliliters of three olive oils with low, medium, and high phenolic content were administered to healthy males (n=182) daily for 3 wk. At study baseline the urinary excretion of 8-oxo-guanosine (RNA oxidation) and 8-oxo-deoxyguanosine (DNA oxidation) was higher in the Northern regions of Europe compared with Central and Southern European regions (P=0.035). Urinary excretion of the 8 hydroxylated forms of guanine, guanosine, deoxyguanosine and their nonoxidized forms were not different when comparing olive oils with low, medium, and high phenolic content given for 2 wk. Testing the effect of oil from urinary 8-oxo-deoxyguanosine changes from baseline to post-treatment showed a reduction of DNA oxidation by 13% (P=0.008). These findings support the idea that ingestion of olive oil is beneficial and can reduce the rate of oxidation of DNA. This effect is not due to the phenolic content in the olive oil. The higher DNA and RNA oxidation in Northern European regions compared with that in Central and Southern regions supports the contention that olive oil consumption may explain some of the North-South differences in cancer incidences in Europe.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Cross-Over Studies; Deoxyguanosine; DNA; DNA Damage; Double-Blind Method; Europe; Humans; Incidence; Male; Neoplasms; Olive Oil; Oxidation-Reduction; Oxidative Stress; Plant Oils; RNA

The 'antioxidant hypothesis' proposes that vitamin C, vitamin E, carotenoids, and other antioxidants occurring in fruit and vegetables afford protection against heart disease and cancer by preventing oxidative damage to lipids and to DNA, respectively. To test elements of this hypothesis, we have measured blood levels of dietary antioxidants, and 8-oxodeoxyguanosine (8-oxo-dG) concentrations in lymphocyte DNA, in healthy men and women from five European countries: France, Ireland, The Netherlands, Spain, and the U.K. Volunteers, aged 25 45, all nonsmokers, gave blood samples before and after a 12-wk carotenoid supplementation regime. Vitamin C was measured in plasma and vitamin E and carotenoids were measured in serum by high-performance liquid chromatography (HPLC). 8-oxo-dG was assayed by HPLC (with coulometric detection) in DNA isolated from lymphocytes from the same blood samples. Mean values were calculated for groups of volunteers at each sampling time according to country, sex, and supplementation (between 9 and 24 individual samples contributing to each mean). We found that 8-oxo-dG levels in lymphocyte DNA vary significantly according to sex and country. A low mean 8-oxo-dG concentration is seen in DNA of women from all five countries, and of men from France and Spain. 8-oxo-dG is significantly higher (up to about threefold) in lymphocyte DNA from men in Ireland and the U.K. Oxidative DNA damage is not significantly affected by carotenoid supplementation; nor is there any association with mean baseline levels of antioxidants, which are generally similar in the five countries. The five countries sampled lie on an axis from northern to southern Europe with a steep gradient in terms of premature heart disease. There is a strong association between premature coronary heart disease mortality in men and the mean levels of 8-oxo-dG for the five countries (r = 0.95, P < 0.01). Women have low coronary heart disease mortality rates, which do not correlate with 8-oxo-dG. In terms of cancer deaths, only colorectal cancer in men shows a significant positive correlation (r = 0.91, P < 0.05), and stomach cancer in women is negatively correlated with DNA oxidation (r = -0.92, P = 0.01).

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Antioxidants; Ascorbic Acid; Carotenoids; Chemoprevention; Deoxyguanosine; DNA Damage; Ethnicity; Europe; Female; Heart Diseases; Humans; Lutein; Lycopene; Lymphocytes; Male; Middle Aged; Neoplasms; Oxidation-Reduction; Palm Oil; Plant Oils; Reactive Oxygen Species; Sex Factors; Single-Blind Method; Vitamin E

Impaired DNA repair activity has been shown to greatly increase rates of cancer clinically. It has been hypothesized that upregulating repair activity in susceptible individuals may be a useful strategy for inhibiting tumorigenesis. Here, we report that selected tyrosine kinase (TK) inhibitors including nilotinib, employed clinically in the treatment of chronic myeloid leukemia, are activators of the repair enzyme Human MutT Homolog 1 (MTH1). MTH1 cleanses the oxidatively damaged cellular nucleotide pool by hydrolyzing the oxidized nucleotide 8-oxo-2'-deoxyguanosine (8-oxo-dG)TP, which is a highly mutagenic lesion when incorporated into DNA. Structural optimization of analogues of TK inhibitors resulted in compounds such as SU0448, which induces 1000 ± 100% activation of MTH1 at 10 μM and 410 ± 60% at 5 μM. The compounds are found to increase the activity of the endogenous enzyme, and at least one (SU0448) decreases levels of 8-oxo-dG in cellular DNA. The results suggest the possibility of using MTH1 activators to decrease the frequency of mutagenic nucleotides entering DNA, which may be a promising strategy to suppress tumorigenesis in individuals with elevated cancer risks.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Carcinogenesis; DNA; DNA Damage; DNA Repair Enzymes; Humans; Neoplasms; Nucleotides; Oxidative Stress; Phosphoric Monoester Hydrolases

The consequences of aging and disease conditions in tissues involve reactive oxygen species (ROS) and related molecular alterations of different cellular compartments. We compared a murine model of immunodeficient (SCID) xenografted young (4 weeks old) and old (17 weeks old) mice with corresponding controls without tumor implantation and carried out a compositional evaluation of brain tissue for changes in parallel DNA and lipids compartments. DNA damage was measured by four purine 5',8-cyclo-2'-deoxynucleosides, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), and 8-oxo-7,8-dihydro-2'-deoxyadenosine (8-oxo-dA). In brain lipids, the twelve most representative fatty acid levels, which were mostly obtained from the transformation of glycerophospholipids, were followed up during the aging and disease progressions. The progressive DNA damage due to age and tumoral conditions was confirmed by raised levels of 5'

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Animals; Brain; DNA; DNA Damage; Fatty Acids; Mice; Mice, SCID; Neoplasms; Purines

Three stochastic microsensors based on graphite powder modified with three different oleamides: N-(2-piperidin-1-ylethyl)oleamide, N-(3,4-dihydroxyphenethyl)oleamide and N-(2-morpholinoethyl)oleamide, were designed, characterized, and used to assess DNA damage in cancer by assaying two biomarkers namely 8-nitroguanine and 8-hydroxy-2'-deoxyguanosine. The two biomarkers were determined from urine and whole blood samples. The characterization of the microsensors was done at two pHs 7.40 and 3.00. The best microsensor for the simultaneous determination of biomarkers in whole blood and urine samples was the one based on the graphite paste modified with N-(3,4-dihydroxyphenethyl)oleamide. The results indicated that the proposed microsensors can be reliably used for pattern recognition and quantitative determination of 8-nitroguanine and 8-hydroxy-2'-deoxyguanosine in whole blood and urine, and accordingly, for the assessment of DNA damage in cancer patients.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers, Tumor; Biosensing Techniques; DNA Damage; Graphite; Guanine; Humans; Neoplasms

Exploiting universal cancer vulnerabilities has been used as an approach for developing targeted therapies. In this issue of

Topics: 8-Hydroxy-2'-Deoxyguanosine; Genomics; Humans; Mitosis; Neoplasms; Reactive Oxygen Species

The determination of the concentrations of urinary biomarkers of oxidative damage to DNA and RNA is difficult due to the low content of targets and the complex matrix of urine. A method using polystyrene/polypyrrole (PS/PPY) electronspun nanofibers as the adsorbent was introduced to the routine urinary treatment and determination of 8-OHdG and 8-oxoG for the first time. And 2-aminoethyl diphenylborate (DPBA) solution was creatively used in the loading and rinsing steps in order to promote the retention of the analytes as well as remove impurities. Under optimal conditions, 8-OHdG, 8-oxoG and IS were separated very well and exhibited a good linearity in the range of 0.5-50 ng mL

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Biomarkers; Chromatography, High Pressure Liquid; DNA; DNA Damage; Guanine; Humans; Limit of Detection; Linear Models; Neoplasms; Oxidative Stress; Reproducibility of Results; RNA; Solid Phase Extraction

Telomeres are capped at the end of the chromosome and gradually shorten when the cell divides. When there is an oxidative stress, it can cause the DNA to be damaged. Hence, 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been shown to be an indicator for oxidative DNA damage. This study aimed to determine the relative telomere length (RTL) and 8-OHdG levels in neoplastic tissues, adjacent non-neoplastic tissues, and blood leukocytes of musculoskeletal (MS) tumor patients. Neoplastic tissues were compared to adjacent non-neoplastic tissues in MS tumor patients (n = 46). Peripheral blood leukocytes (PBLs) of MS tumor subjects were compared to those of age-matched healthy controls (n = 107). RTL was evaluated by quantitative real-time polymerase chain reaction and 8-OHdG levels were quantified by enzyme-linked immunosorbent assay. The RTL in neoplastic tissues was significantly shorter than that in non-neoplastic tissues [1.12 (0.86-1.46) vs 1.45 (1.25-1.65), P = 0.001]. PBLs had lower RTL than non-neoplastic tissues in MS tumor patients [1.04 (0.85-1.13) vs 1.45 (1.25-1.65), P < 0.001]. However, there was no significant difference between RTL in PBLs and in neoplastic tissues. In addition, PBLs of MS tumor patients had higher RTL than those of the controls [1.04 (0.85-1.13) versus 0.78 (0.68-0.90), P < 0.001]. The 8-OHdG levels in neoplastic tissues were remarkably higher than those in non-neoplastic tissues [8.14 (6.81-11.37) nM/μg/μl vs. 3.79 (2.53-6.17) nM/μg/μl, P < 0.001]. Furthermore, plasma 8-OHdG levels in MS tumor patients were markedly greater than those in the controls [102.50 (73.16-133.50) nM vs. 41.09 (6.81-11.37) nM, P < 0.001]. Area under the curve (AUC) was 0.7536 (95% confident interval (CI) 0.6602-0.8469) when the cut-off value of RTL in PBLs was 0.97. Also, plasma 8-OHdG levels depicted that when the cut-off value was 38.67 nM, the AUC was 0.7723 (95% CI 0.6920-0.8527). Moreover, ROC curve analysis showed that both RTL and 8-OHdG appeared to improve the sensitivity (85.68%) and specificity (70.91%) with the AUC 0.8639 (95% CI 0.7500-0.9500). This study suggested that blood leukocyte RTL and plasma 8-OHdG could serve as promising non-invasive biomarkers to differentiate between MS tumor patients and healthy controls. Additionally, telomere attrition and increased oxidative DNA damage might play contributory roles in the pathogenesis of MS tumors.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Biomarkers, Tumor; Bone Neoplasms; Female; Humans; Leukocytes; Male; Middle Aged; Musculoskeletal System; Neoplasms; Neoplasms, Muscle Tissue; Oxidative Stress; Prognosis; Risk Factors; Telomere; Telomere Homeostasis

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Biomarkers; Chromatography, High Pressure Liquid; Creatine; Deoxyguanosine; DNA; Female; Guanosine; Humans; Limit of Detection; Male; Neoplasms; Neurodegenerative Diseases; Oxidative Stress; RNA; Solid Phase Extraction; Tandem Mass Spectrometry; Young Adult

Previously, we showed cancer cells rely on the MTH1 protein to prevent incorporation of otherwise deadly oxidised nucleotides into DNA and we developed MTH1 inhibitors which selectively kill cancer cells. Recently, several new and potent inhibitors of MTH1 were demonstrated to be non-toxic to cancer cells, challenging the utility of MTH1 inhibition as a target for cancer treatment.. Human cancer cell lines were exposed in vitro to MTH1 inhibitors or depleted of MTH1 by siRNA or shRNA. 8-oxodG was measured by immunostaining and modified comet assay. Thermal Proteome profiling, proteomics, cellular thermal shift assays, kinase and CEREP panel were used for target engagement, mode of action and selectivity investigations of MTH1 inhibitors. Effect of MTH1 inhibition on tumour growth was explored in BRAF V600E-mutated malignant melanoma patient derived xenograft and human colon cancer SW480 and HCT116 xenograft models.. Here, we demonstrate that recently described MTH1 inhibitors, which fail to kill cancer cells, also fail to introduce the toxic oxidized nucleotides into DNA. We also describe a new MTH1 inhibitor TH1579, (Karonudib), an analogue of TH588, which is a potent, selective MTH1 inhibitor with good oral availability and demonstrates excellent pharmacokinetic and anti-cancer properties in vivo.. We demonstrate that in order to kill cancer cells MTH1 inhibitors must also introduce oxidized nucleotides into DNA. Furthermore, we describe TH1579 as a best-in-class MTH1 inhibitor, which we expect to be useful in order to further validate the MTH1 inhibitor concept.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cell Line, Tumor; Deoxyguanosine; DNA; DNA Repair Enzymes; Enzyme Inhibitors; Humans; Mice; Neoplasms; Nucleotides; Oxidation-Reduction; Phosphoric Monoester Hydrolases; Proto-Oncogene Proteins B-raf; Pyrimidines; RNA, Small Interfering; Xenograft Model Antitumor Assays

Due to the importance of the identification of chemotherapy outcome prognostic factors, we attempted to establish the potential of oxidative stress/DNA damage parameters such as prognostic markers. The aim of the study was to determine whether platinum derivative-based chemotherapy in cancer patients (n = 66) is responsible for systemic oxidatively damaged DNA and whether damage biomarkers, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and the modified base 8-oxo-7,8-dihydroguanine (8-oxo-Gua), in urine and DNA may be used as a prognostic factor for the outcome of chemotherapy. All the aforementioned modifications were analyzed using techniques involving high-performance liquid chromatography/electrochemical detection (HPLC/EC) or HPLC/gas chromatography-mass spectrometry (GC-MS). Among all the analyzed parameters, the significantly decreased levels of 8-oxo-Gua in urine collected from a subgroup of patients 24 h after the first infusion of the drug, as compared with the baseline levels, correlated with a significantly longer overall survival (OS) (60 months after therapy) than in the subgroup without any decrease of this parameter after therapy (median OS = 24 months, p = 0.007). Moreover, a significantly longer OS was also observed in a group with increased urine levels of 8-oxo-dG after chemotherapy (38.6 vs. 20.5 months, p = 0.03). The results of our study suggest that patients with decreased 8-oxo-Gua levels and increased 8-oxo-dG levels in urine 24 h after the first dose should be considered as better responders to the administered chemotherapy, with a lower risk of death. The conclusion may permit the use of these parameters as markers for predicting the clinical outcome of platinum derivative-based chemotherapy.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Antineoplastic Agents; Biomarkers; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Drug Monitoring; Drug Therapy; Female; Gas Chromatography-Mass Spectrometry; Guanine; Humans; Male; Middle Aged; Neoplasms; Oxidative Stress; Prognosis; Treatment Outcome

Nanoparticles (NPs) are considered to influence the inflammatory process; however, the precise mechanism and the significance in tumors are still not clear. In this study, when CT26 and LL2 mouse cancer cells were treated with 6-nm anatase titanium dioxide NPs (TDNPs) without ultraviolet irradiation, oxidative stress and induction of inflammatory cytokines were observed. Oxidative stress was further increased by disease-associated conditions such as high glucose concentrations and hypoxia. Inhaled or orally administered TDNPs generated granulomatous lesions in the lungs and colon of the rodent models tested, with increased oxidative stress and inflammatory cytokines. Oxidative stress and inflammatory cytokines were also found in cancer cells treated with gold or carbon black NPs. Treatment of CT26 cells with 10- to 70-nm rutile TDNPs showed that smaller NPs produced more oxidative stress and inflammatory cytokines than larger ones did. To avoid diffusion of TDNPs and to minimize toxicity, 10-nm TDNPs were suspended in a collagen gel inserted into a subcutaneous tumor in a CT26 mouse. A single TDNP treatment via this method inhibited tumor growth in a size- and dose-dependent manner, and resulted in lower levels of urinary 8-OHdG when compared to systemically administered TDNPs. These findings suggest that TDNPs might be useful for the local treatment of tumors.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cell Hypoxia; Cell Line, Tumor; Colon; Cytokines; Deoxyguanosine; Disease Models, Animal; Drug Administration Routes; Gold; Lung; Metal Nanoparticles; Mice; Neoplasms; Oxidative Stress; Rats; Soot; Titanium; Ultraviolet Rays

This work proposes a novel approach for a suitable orientation of antibodies (Ab) on an immunosensing platform, applied here to the determination of 8-hydroxy-2'-deoxyguanosine (8OHdG), a biomarker of oxidative stress that has been associated to chronic diseases, such as cancer. The anti-8OHdG was bound to an amine modified gold support through its Fc region after activation of its carboxylic functions. Non-oriented approaches of Ab binding to the platform were tested in parallel, in order to show that the presented methodology favored Ab/Ag affinity and immunodetection of the antigen. The immunosensor design was evaluated by quartz-crystal microbalance with dissipation, atomic force microscopy, electrochemical impedance spectroscopy (EIS) and square-wave voltammetry. EIS was also a suitable technique to follow the analytical behavior of the device against 8OHdG. The affinity binding between 8OHdG and the antibody immobilized in the gold modified platform increased the charge transfer resistance across the electrochemical set-up. The observed behavior was linear from 0.02 to 7.0 ng/mL of 8OHdG concentrations. The interference from glucose, urea and creatinine was found negligible. An attempt of application to synthetic samples was also successfully conducted. Overall, the presented approach enabled the production of suitably oriented Abs over a gold platform by means of a much simpler process than other oriented-Ab binding approaches described in the literature, as far as we know, and was successful in terms of analytical features and sample application.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Antibodies, Immobilized; Biomarkers, Tumor; Biosensing Techniques; Deoxyguanosine; Dielectric Spectroscopy; Gold; Humans; Microscopy, Atomic Force; Neoplasms; Oxidative Stress

Kinetic exclusion analysis (KinExA)-based immunosensors and enzyme-linked immunosorbent assays (ELISA) have been developed and validated for measurement of five different cancer markers in biological specimens. These markers were: 2'-deoxycytidine (dCyd), 8-hydroxy-2'-deoxyguanosine (8HdG), carbohydrate antigen (CA15-3), α-fetoprotein (AFP), and β-subunit of human chorionic gonadotropin (β-HCG). The KinExA-based assays were conducted on the KinExA™ 3200 instrument. The ELISA assays employed the competitive immunoassay format for dCyd and 8HdG, however they employed the direct sandwich-type format for CA15-3, AFP, and β-HCG. Each assay was validated in terms of its limit of detection, working range, precision profile, and accuracy. The analytical performances of the KinExA-based sensors were found to be superior to the ELISA for the five markers. The data demonstrated that the format of the assay may influence its performance characteristics (sensitivity, precision, etc.), even when exactly the same reagents are employed. The superior performance of the KinExA format is most likely due to: (1) the high surface area of beads containing the immobilized capture in the flow cell of the instrument, (2) the high flow rate of the reagents passing through the beads, which minimizes the diffusion limitations at the reaction surface, and (3) the limited time that the antibody is in contact with the capture reagent. The KinExA-based assays exhibited three noteworthy properties compared with ELISA: (1) avoiding the problems of mass transport limitations, and mobility effects, (2) KinExA analysis with automated sampling increase the assay convenience; and (3) providing high sensitivity with a lower limit of detection and better precision than ELISA. The proposed KinExA-based immunosensors are anticipated to have a great value in measurement of the cancer markers where more confident results are needed.

Topics: 8-Hydroxy-2'-Deoxyguanosine; alpha-Fetoproteins; Biomarkers, Tumor; Biosensing Techniques; Calibration; Chorionic Gonadotropin, beta Subunit, Human; Deoxycytidine; Deoxyguanosine; Enzyme-Linked Immunosorbent Assay; Humans; Mucin-1; Neoplasms; Reproducibility of Results; Sensitivity and Specificity

Because of the importance to identify prognostic indicator for radiotherapy, herein we decided to check whether the parameters which describe oxidative stress/DNA damage may be used as a marker of the therapy. The aim of this work was to investigate whether fractionated radiotherapy of patients with cancer (n = 99) is responsible for oxidative DNA damage on the level of the whole organism and whether the biomarkers of the damage such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and its modified base 8-oxo-7,8-dihydroguanine (8-oxo-Gua) in urine and DNA may be used as a predictor of radiotherapy success.. All the aforementioned modifications were analyzed using techniques which involve high-performance liquid chromatography/electrochemical detection (HPLC/EC) or HPLC/gas chromatography-mass spectroscopy (GC-MS).. Of all analyzed parameters only patients with significantly elevated urinary excretion of the 8-oxo-Gua with concomitant unchanged level of 8-oxo-dG in leukocytes DNA in the samples collected 24 hours after the first fraction in comparison to the initial level have significantly increased survival time (60 months after the treatment, survival of 50% of the patients who fulfill the above mentioned criteria, in comparison with 10% of the patients who did not).. Results of our work suggest that patients with higher urinary 8-oxo-Gua and concomitant stable level of 8-oxo-dG in leukocytes DNA, after 24 hours of the first dose should be regarded as better responder to radiotherapy as being at lower risk of mortality.. The above mentioned statement could make it possible to use these parameters as markers to predict the clinical success.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Female; Guanine; Humans; Leukocytes; Male; Middle Aged; Neoplasms; Oxidation-Reduction; Oxidative Stress; Prognosis; Radiation Oncology; Survival Rate

Some industrial hygiene studies have assessed occupational exposure to antineoplastic drugs; other epidemiological investigations have detected various toxicological effects in exposure groups labeled with the job title. In no research has the same population been studied both environmentally and epidemiologically. The protocol of the epidemiological study presented here uses an integrated environmental and biological monitoring approach. The aim is to assess in hospital nurses preparing and/or administering therapy to cancer patients the current level of occupational exposure to antineoplastic drugs, DNA and chromosome damage as cancer predictive effects, and the association between the two.. About 80 healthy non-smoking female nurses, who job it is to prepare or handle antineoplastic drugs, and a reference group of about 80 healthy non-smoking female nurses not occupationally exposed to chemicals will be examined simultaneously in a cross-sectional study. All the workers will be recruited from five hospitals in northern and central Italy after their informed consent has been obtained.Evaluation of surface contamination and dermal exposure to antineoplastic drugs will be assessed by determining cyclophosphamide on selected surfaces (wipes) and on the exposed nurses' clothes (pads). The concentration of unmetabolized cyclophosphamide as a biomarker of internal dose will be measured in end-shift urine samples from exposed nurses. Biomarkers of effect and susceptibility will be assessed in exposed and unexposed nurses: urinary concentration of 8-hydroxy-2-deoxyguanosine; DNA damage detected using the single-cell microgel electrophoresis (comet) assay in peripheral white blood cells; micronuclei and chromosome aberrations in peripheral blood lymphocytes. Genetic polymorphisms for enzymes involved in metabolic detoxification (i.e. glutathione S-transferases) will also be analysed.Using standardized questionnaires, occupational exposure will be determined in exposed nurses only, whereas potential confounders (medicine consumption, lifestyle habits, diet and other non-occupational exposures) will be assessed in both groups of hospital workers.Statistical analysis will be performed to ascertain the association between occupational exposure to antineoplastic drugs and biomarkers of DNA and chromosome damage, after taking into account the effects of individual genetic susceptibility, and the presence of confounding exposures.. The findings of the study will be useful in updating prevention procedures for handling antineoplastic drugs.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Antineoplastic Agents; Biomarkers; Chromosome Aberrations; Cross-Sectional Studies; Cyclophosphamide; Deoxyguanosine; DNA Damage; Environmental Monitoring; Female; Humans; Italy; Neoplasms; Nursing Staff, Hospital; Occupational Diseases; Occupational Exposure; Oncology Nursing; Risk

The broad spectrum of oxidative damage DNA biomarkers: urinary excretion of 8-oxodG (8-oxo-7,8-dihydro-2'-deoxyguanosine), 8-oxoGua (8-oxo-7,8-dihydroguanine) as well as the level of oxidative damage DNA in leukocytes, was analyzed in cancer patients and healthy subjects.. 222 cancer patients and 134 healthy volunteers were included in the analysis, using methodologies which involve HPLC (high-performance liquid chromatography) prepurification followed by gas chromatography with isotope dilution mass spectrometry detection and HPLC/EC.. For the whole patient population (n=222) the median values of 8-oxoGua and 8-oxodG in urine samples were 12.44 (interquartile range: 8.14-20.33) [nmol/24 hr] and 6.05 (3.12-15.38) [nmol/24 hr], respectively. The median values of 8-oxoGua and 8-oxodG in urine samples of the control group (n=85) were 7.7 (4.65-10.15) [nmol/24 hr] and 2.2 (1.7-2.8) [nmol/24 hr], respectively. The level of 8-oxodG in DNA isolated from leukocytes of the patient population (n=179) and of the control group (n=134) was 4.93 (3.46-9.27) per 10'6 dG and 4.46 (3.82-5.31) per 10'6 dG, respectively.. The results suggest that oxidative stress in cancer patients, demonstrated by augmented amounts of these modifications in urine, could be typical not only for affected tissue but also for other tissues and even the whole organism. An assay that enables the determination of levels of basic markers of oxidative stress might be applied in clinical practice as an additional, helpful marker to diagnose cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers, Tumor; Case-Control Studies; Deoxyguanosine; DNA Damage; DNA, Neoplasm; Guanine; Humans; Leukocytes; Neoplasms; Oxidative Stress

Carcinogen-mediated labilization of lysosomal enzymes such as β-glucuronidase (βG) is often associated with the general process of inflammation. Therefore, the primary goal of this study was to demonstrate that exposing the skin of SENCAR mice to the natural βG inhibitor D-glucaro-1,4-lactone (1,4-GL) and its precursor D-glucuronic acid-γ-lactone (GUL), prior to and during 7,12-dimethylbenz[α]anthracene (DMBA) treatment inhibits not only epidermal hyperplasia but also inflammation in the mouse skin complete carcinogenesis model, i.e., the 4-week inflammatory-hyperplasia assay. Topical administration of 1,4-GL or GUL prior to repetitive, high-dose DMBA treatment markedly and in a dose-related manner inhibited DMBA-induced epidermal hyperplasia (i.e., up to 57%). DMBA-mediated Ha-ras mutations in codon 61 were reduced by up to 78% by 1,4-GL. DMBA-induced inflammation, as measured by dermal leukocyte counts and immunologically, was inhibited by up to 37% by topical 1,4-GL but not by GUL. The inhibition of cellular proliferation and inflammation coincided with the inhibition of βG expression. Thus, the present study suggests that in the DMBA-induced complete skin carcinogenesis model, 1,4-GL when applied topically had both anti-proliferative properties as well as anti-inflammatory properties, whereas GUL had only anti-proliferative when applied topically. However, the number of inflammatory cells in the dermal portion of the skin of mice was significantly reduced by dietary treatment of GUL, whereas both topical and dietary treatments with 1,4-GL were very effective.

Topics: 8-Hydroxy-2'-Deoxyguanosine; 9,10-Dimethyl-1,2-benzanthracene; Administration, Oral; Administration, Topical; Animals; Anticarcinogenic Agents; Biomarkers; Carcinogens; Deoxyguanosine; Dermatitis, Contact; Female; Glucaric Acid; Glucuronates; Glucuronidase; HSP90 Heat-Shock Proteins; Hyperplasia; Inflammation Mediators; Interleukin-1alpha; Leukocyte Count; Mice; Mice, Inbred SENCAR; Neoplasms; Skin

Colitis-associated cancer (CAC) is one of clear examples of inflammation-carcinogenesis sequence, by which the strict control of colitis with potent anti-inflammatory or antioxidative agent offers the chance of cancer prevention. Supported with the facts that Rac1 binds and activates STAT3, which are significantly upregulated in inflammatory bowel disease (IBD) as well as CAC, but 8-hydroxydeoxyguanosine (8-oxo-7,8-dihydrodeoxyguanosine or 8-OHdG) paradoxically can block Rac1 activation and subsequent NADPH oxidase (NOX) inactivation in various inflammation models, we hypothesized that attenuated Rac1-STAT3 and COX-NF-κB pathway by exogenous 8-OHdG administration may ameliorate inflammatory signaling in dextran sodium sulfate (DSS)-induced colitis and can prevent CAC. Before commencing carcinogenesis model, we checked whether exogenous 8-OHdG can alleviate IBD, for which interleukin (IL)-10 knockout mice were designed to ingest 5% DSS for 1 week, and 8-OHdG is given through intraperitoneal route daily. 8-OHdG treatment groups significantly reduced pathologic grade of DSS-induced colitis as well as various inflammatory mediators such as TNF-α, IL-6, COX-2, and iNOS in a dose-dependent manner. To document the cancer prevention effects of 8-OHdG, mice were injected azoxymethane followed by drinking 2.5% DSS for 1 week, after which 8-OHdG-containing diets were given for 20 weeks. As results, mice that consumed 8-OHdG-containing diet significantly reduced both tumor incidence and multiplicity. Rac1 activity and phosphorylated STAT3 level were significantly attenuated in the 8-OHdG-treated group. Significantly decreased levels of malondialdehyde, monocyte chemotactic protein-1, matrix metalloproteinasess, COX-2, NOX4, and β-catenin nuclear accumulation were responsible for cancer prevention effects of exogenous 8-OHdG. In conclusion, we clearly showed cancer-preventive effect of exogenous 8-OHdG against CAC.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anticarcinogenic Agents; Azoxymethane; Colitis; Colorectal Neoplasms; Deoxyguanosine; Dextrans; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Inflammation; Interleukin-10; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Neoplasms; STAT3 Transcription Factor; Sulfates

A sensitive and low-cost analytical method has been developed to determine 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-nitroguanine (8-NO(2)Gua) based on capillary electrophoresis with amperometric detection (CE-AD) after solid phase extraction (SPE). Under optimized condition, these two markers were well separated from other components coexisting in urine, exhibiting a linear calibration over the concentration range of 0.1-50.0 μg/mL with the detection limits ranging from 0.02 to 0.06 μg/mL. The relative standard deviations (RSDs) were in the range of 0.1-2.1% for peak area, 0.1-1.5% for migration time, respectively. The average recovery and RSD were within the range of 100.0-108.0% and 0.1-1.7%, respectively. It was found that the urinary contents of 8-OHdG and 8-NO(2)Gua in cancer patients were significantly higher than those in healthy ones.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Biomarkers; Deoxyguanosine; DNA Damage; Electrophoresis, Capillary; Female; Guanine; Humans; Hydrogen-Ion Concentration; Limit of Detection; Male; Middle Aged; Neoplasms; Reproducibility of Results; Solid Phase Extraction

Curcumin (diferuloylmethane), a biologically active ingredient derived from rhizome of the plant Curcuma longa, has potent anticancer properties as demonstrated in a plethora of human cancer cell lines/animal carcinogenesis model and also acts as a biological response modifier in various disorders. We have reported previously that dietary supplementation of curcumin suppresses renal ornithine decarboxylase (Okazaki et al. Biochim Biophys Acta 1740:357-366, 2005) and enhances activities of antioxidant and phase II metabolizing enzymes in mice (Iqbal et al. Pharmacol Toxicol 92:33-38, 2003) and also inhibits Fe-NTA-induced oxidative injury of lipids and DNA in vitro (Iqbal et al. Teratog Carcinog Mutagen 1:151-160, 2003). This study was designed to examine whether curcumin possess the potential to suppress the oxidative damage caused by kidney-specific carcinogen, Fe-NTA, in animals. In accord with previous report, at 1 h after Fe-NTA treatment (9.0 mg Fe/kg body weight intraperitoneally), a substantial increased formation of 4-hydroxy-2-nonenal (HNE)-modified protein adducts in renal proximal tubules of animals was observed. Likewise, the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and protein reactive carbonyl, an indicator of protein oxidation, were also increased at 1 h after Fe-NTA treatment in the kidneys of animals. The prophylactic feeding of animals with 1.0% curcumin in diet for 4 weeks completely abolished the formation of (i) HNE-modified protein adducts, (ii) 8-OHdG, and (iii) protein reactive carbonyl in the kidneys of Fe-NTA-treated animals. Taken together, our results suggest that curcumin may afford substantial protection against oxidative damage caused by Fe-NTA, and these protective effects may be mediated via its antioxidant properties. These properties of curcumin strongly suggest that it could be used as a cancer chemopreventive agent.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Antioxidants; Carcinogens; Chemoprevention; Curcumin; Deoxyguanosine; Ferric Compounds; Kidney; Kidney Tubules, Proximal; Male; Mice; Neoplasms; Nitrilotriacetic Acid; Oxidative Stress; Proteins

Chronic inflammation is induced by various infectious/infected agents and by many physical, chemical and immunological factors. Many malignancies arise from areas of infection and inflammation. Reactive oxygen species and reactive nitrogen species are considered to play the key role in inflammation-associated carcinogenesis by causing oxidative and nitrative DNA damage. 8-Nitroguanine is a mutagenic nitrative DNA lesion formed during inflammation. Development of a detection method for 8-nitroguanine would provide an insight into the mechanism of inflammation-associated carcinogenesis and the assessment of carcinogenic risk in patients with inflammatory diseases. We established the method to produce highly sensitive and specific anti-8-nitroguanine rabbit polyclonal antibody, and detect 8-nitroguanine formation in biopsy specimens and animal tissues by immunohistochemistry. We have found that 8-nitroguanine is formed at the sites of carcinogenesis regardless of etiology, and proposed the possibility that 8-nitroguanine is a potential biomarker to evaluate the risk of inflammation-associated carcinogenesis. In this paper, we describe the procedures of these experiments and the application to clinical specimens and animal tissues.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Biomarkers, Tumor; Deoxyguanosine; DNA Damage; Fluorescent Antibody Technique, Indirect; Guanine; Humans; Inflammation; Neoplasms; Rabbits; Reactive Nitrogen Species

Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been widely used as a biomarker of oxidative DNA damage. Measurements of 8-OHdG in urinary samples are challenging owing to the low level of 8-OHdG and the complex matrix. In this study, a novel molecularly imprinted polymer (MIP) monolithic column was synthesized with guanosine as a dummy template which was used as the medium for in-tube solid-phase microextraction (SPME). In-tube SPME coupled with HPLC/UV detection for extraction and determination of urinary 8-OHdG was developed. The synthesized MIP monolithic column exhibited high extraction efficiency owing to its greater phase ratio with convective mass transfer and inherent selectivity. The enrichment factor for 8-OHdG was found to be 76 and the limits of detection and quantification of the method for urinary samples were 3.2 nmol/L (signal-to-noise ratio 3) and 11 nmol/L (signal-to-noise ratio 10), respectively. The MIP(')s selectivity also made the sample preparation procedure and chromatographic separation much easier. The linear range of the proposed method was from 0.010 to 5.30 micromol/L (r = 0.9997), with a relative standard deviation of 1.1-6.8%, and the recovery for spiked urine samples was 84 +/- 3%. The newly developed method was successfully applied to determine urinary samples of healthy volunteers, coking plant workers, and cancer patients. The 8-OHdG level in cancer patients was significantly higher than that in healthy people.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Chromatography, High Pressure Liquid; Deoxyguanosine; Equipment Design; Guanosine; Humans; Middle Aged; Molecular Imprinting; Neoplasms; Sensitivity and Specificity; Solid Phase Microextraction; Young Adult

A number of epidemiological studies suggest that the consumption of green tea reduces the incidence of prostate cancer. As the major catechins present in green tea are potent antioxidants, we hypothesized that genetic and cellular damage induced by oxygen free radicals could be significantly reduced by potent antioxidants in green tea, thus reducing the cumulative genetic and cellular damage with age, and slowing or preventing tumour formation. Long-term administration of a decaffeinated green tea extract to Lobund-Wistar rats for periods up to 26 months almost halved the incidence of primary tumours in the genitourinary tract when compared with an age-matched cohort receiving just water. We observed no inhibition of DNA adduct formation or lipid peroxidation in animals consuming green tea compared with animals consuming deionized water. The decrease in tumour formation was associated with an increase in 8-hydroxy-2'deoxyguanosine and 4-hydroxynonenal content (markers of DNA adduct formation and lipid peroxidation, respectively) in the epithelium of the ventral prostate in aging animals. In addition, there was an increase in 8-hydroxy-2'deoxyguanosine expression, but no change in 4-hydroxynonenal expression in the seminal vesicles of older animals. An age-associated increase in expression of the antioxidant enzymes manganese superoxide dismutase and catalase in the epithelium of the ventral prostate of aging animals was observed. Furthermore, there was also an increase in manganese superoxide dismutase expression, but no change in catalase expression in the seminal vesicles of older animals. These data demonstrate that consumption of green tea decreases the incidence of genitourinary tract tumours in the Lobund-Wistar rat, but has no effect on age-associated DNA adduct formation and lipid peroxidation in the ventral prostate and seminal vesicles of the aging rat.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Catalase; Deoxyguanosine; DNA Damage; Incidence; Lipid Peroxidation; Male; Neoplasms; Oxidative Stress; Plant Extracts; Prostate; Rats; Rats, Wistar; Seminal Vesicles; Superoxide Dismutase; Tea; Urogenital Neoplasms

Urinary 8-hydroxy-2'-deoxyguanosine (8OHdG) is an excellent marker of oxidative DNA damage. Until now, urinary 8OHdG has been measured by high-performance liquid chromatography with electrochemical detection. A simple and sensitive method for the analysis of urinary 8OHdG by capillary electrophoresis with end-column amperometric detection has been developed and is described in this chapter. A single-step solid-phase extraction procedure was optimized and used for extracting 8OHdG from human urine. To improve the sensitivity of this method, a new focusing technique based on a dynamic pH junction was used. In the end, the urinary concentration of 8OHdG in healthy persons, patients with cancer, patients with diabetic nephropathy, and smokers was determined. Emphasis is focused on the establishment and application of the methods.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Deoxyguanosine; Diabetic Nephropathies; DNA Damage; Electrolytes; Electrophoresis, Capillary; Humans; Hydrogen-Ion Concentration; Neoplasms; Oxidative Stress; Reproducibility of Results; Smoking

Vitamins A, E and C, and uric acid, which can scavenge free radicals should also protect DNA from the damage. It is reasonable to assume that agents that decrease oxidative DNA damage should also decrease subsequent cancer development.. A relationship between basal level of antioxidants (vitamins A, C and E and uric acid) and oxidative DNA damage was assessed. For the first time, the broad spectrum of oxidative DNA damage biomarkers: urinary excretion of 8-oxodG, 8-oxoGua and 5HMUra as well as the level of oxidative DNA damage in leukocytes was analyzed in healthy subjects (n = 158).. Using HPLC prepurification/isotope dilution GC/MS methodology, we examined the amount of oxidative DNA damage products excreted into urine and the amount of 8-oxodG in leukocytes' DNA (with HPLC/EC technique). The level of antioxidant vitamins and uric acid was estimated by HPLC technique with fluorimetric and UV detection.. Analyses of relationship between the most common antioxidants (vitamins A, C, E and uric acid) and oxidative DNA damage products reveal weak, statistically significant negative correlation between retinol and all the measured parameters except 5HMUra. Vitamin C negatively correlates with urinary excretion of 8-oxodG and 8-oxoGua. Uric acid revealed statistically significant negative correlation with 8-oxodG in cellular DNA and urinary excretion of 5HMUra, while alpha-tocopherol correlates negatively only with 8-oxodG in cellular DNA. Good, significant (P < 0.0001), positive correlation (r = 0.61) was noted between urinary levels of the base, 8-oxoGua and the deoxynucleoside, 8-oxodG.. Our results suggest that oxidative DNA damage shows limited but significant response to antioxidants analyzed in this study and is more affected by many other cellular functions like antioxidant enzymes or DNA repair enzymes as well as genetics.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Aged, 80 and over; Antioxidants; Biomarkers; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Female; Free Radical Scavengers; Guanine; Humans; Leukocytes; Male; Middle Aged; Neoplasms; Oxidation-Reduction; Oxidative Stress; Uric Acid; Vitamins

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers, Tumor; Deoxyguanosine; DNA; DNA Damage; Humans; Neoplasms; Oxidative Stress; Risk Assessment

Intracellular oxidative stress from mitochondria is thought to be important in carcinogenesis and tumorigenesis, but direct experimental proof is limited. In this study, a transgenic mouse cell line (SDHC E69) with a mutated SDHC gene (a subunit of complex II in the electron transport chain) was constructed to test this question. The SDHC E69 cells overproduced superoxide anion (O(2)(-)) from mitochondria, had elevated cytoplasmic carbonyl proteins and 8-OH-deoxyguanine in their DNA as well as significantly higher mutation frequencies than wild type. There were many apoptotic cells in this cell line, as predicted by the observed increase in caspase 3 activity, decrease in mitochondrial membrane potential, and structural changes in their mitochondria. In addition, some cells that escaped from apoptosis underwent transformation, as evidenced by the fact that SDHC E69 cells caused benign tumors when injected under the epithelium of nude mice. These results underscore the notion that mitochondrially generated oxidative stress can contribute to nuclear DNA damage, mutagenesis, and ultimately, tumorigenesis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Amino Acid Sequence; Animals; Apoptosis; Bacterial Proteins; Base Sequence; Caspase 3; Caspases; Cloning, Molecular; Deoxyguanosine; DNA Primers; Gene Frequency; Humans; Membrane Proteins; Mice; Mice, Transgenic; Molecular Sequence Data; Neoplasms; Oxidative Stress; Polymerase Chain Reaction; Sequence Alignment; Sequence Homology, Amino Acid; Succinate Dehydrogenase; Superoxides

The potential link between depression and cancer is an important unsolved question. To clarify this, we compared a cancer-related oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OH-dG), in peripheral leukocytes between 30 patients with depression and 60 age- and gender-matched healthy controls, and examined the 8-OH-dG-related factors. The degree of depression was assessed by the scores of the Center for Epidemiologic Studies Depression scale (CES-D) and the Profile of Mood States (POMS). The patients showed significantly higher 8-OH-dG levels than the controls. There was a significant positive correlation between the CES-D scores and the 8-OH-dG levels in depressive, particularly female, patients. Multiple regression analysis indicated that whether the subjects were patients or controls was a significant predictor of the 8-OH-dG levels in male and total subjects, as was the CES-D score or the Depression-Rejection score of the POMS in female subjects. This study suggests that clinical depression is a risk factor for cancer initiation in view of oxidative DNA damage.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Case-Control Studies; Deoxyguanosine; Depression; DNA Damage; Female; Humans; Male; Middle Aged; Neoplasms; Oxidative Stress; Risk Factors

8-Hydroxy-2'-deoxyguanosine (8OHdG) has been considered as an excellent marker of oxidative DNA damage associated with age-related diseases such as cancer. In this paper, two sensitive methods-capillary electrophoresis with electrochemical detection (CE-ECD) and gas chromatography/mass spectrometry (GC/MS) were developed for urinary 8OHdG analysis. The R.S.D. of the spiked recovery of the two methods for determining urinary 8OHdG was 4.03% and 8.25%, respectively, and the results from the two methods have a good consistency (r=0.999, P<0.01). The developed CE-ECD method was applied to investigate the urinary 8OHdG levels in different cancer patients and follow up the response of therapy. It was found that the excretion levels of urinary 8OHdG in cancer patients were significantly higher than those in healthy persons (35.26+/-27.96 nM versus 13.51+/-5.08 nM, P<0.05), and cancer patients receiving surgical therapy and chemotherapy showed a significant decrease in urinary 8OHdG.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Antineoplastic Agents; Deoxyguanosine; DNA Damage; Electrochemistry; Electrophoresis, Capillary; Female; Gas Chromatography-Mass Spectrometry; Humans; Male; Middle Aged; Neoplasms; Reproducibility of Results

In mammalian cells, more than one genome in a single cell has to be maintained throughout the entire life of the cell, namely, one in the nucleus and the other in the mitochondria. The genomes and their precursor nucleotides are highly exposed to reactive oxygen species, which are inevitably generated as a result of the respiratory function in mitochondria. To counteract such oxidative damage in nucleic acids, cells are equipped with several defense mechanisms. Modified nucleotides in the nucleotide pools are hydrolyzed, thus avoiding their incorporation into DNA or RNA. Damaged bases in DNA with relatively small chemical alterations are mainly repaired by the base excision repair (BER) system, which is initiated by the excision of damaged bases by specific DNA glycosylases. MTH1 protein hydrolyzes oxidized purine nucleoside triphosphates, such as 8-oxo-dGTP, 8-oxo-dATP, and 2-hydroxy (OH)-dATP to the monophosphates, and MTH1 are located in the cytoplasm, mitochondria, and nucleus. We observed an increased susceptibility to spontaneous carcinogenesis in Mth1-deficient mice and an alteration of MTH1 expression along with the accumulation of 8-oxo-dG in patients with various neurodegenerative diseases. Enzymes for the BER pathway, namely, 8-oxoG DNA glycosylase (OGG1), 2-OH-A/adenine DNA glycosylase (MUTYH), and AP endonuclease (APEX2) are also located both in the mitochondria and in the nuclei, and the expression of mitochondrial OGG1 is altered in patients with various neurodegenerative diseases. We also observed increased susceptibilities to spontaneous carcinogenesis in OGG1 and MUTYH-deficient mice. The increased occurrence of lung tumor in OGG1-deficient mice was completely abolished by the concomitant disruption of the Mth1 gene.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cell Line; Deoxyguanosine; DNA Damage; DNA Glycosylases; DNA Repair; DNA-(Apurinic or Apyrimidinic Site) Lyase; Endonucleases; Genetic Predisposition to Disease; Humans; Mice; Multifunctional Enzymes; N-Glycosyl Hydrolases; Neoplasms; Neurodegenerative Diseases; Nucleic Acids; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Biomarkers; Deoxyguanosine; DNA; DNA Damage; Humans; Neoplasms; Oxidation-Reduction

A capillary electrophoresis method with UV detection was developed for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in untreated urine samples. The calibration graph for 8-OHdG in urine is linear in the concentration range 10-500 mg/l. and the detection limit is 5 mg/l (17 microM). 8-OHdG was determined in urine from oncological patients treated by radiation therapy. Its concentrations relative to creatinine were found to be in the range 10-47 microg 8-OHdG/l mg creatinine (4-19 micromol 8-OHdG/mmol creatinine). The overall time of the analysis of a urine sample was less than 15 min.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Calibration; Deoxyguanosine; Electrophoresis, Capillary; Humans; Neoplasms; Spectrophotometry, Ultraviolet

Increased risks of cancers and oxidative DNA damage have been observed in diabetic patients. Many endogenous aldehydes such as 3-deoxyglucosone and glyceraldehyde (GA) increase under hyperglycemic conditions. We showed that these aldehydes induced Cu(II)-mediated DNA damage, including 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation. GA had the strongest ability to damage DNA, and addition of low concentrations of H2O2 markedly enhanced the DNA damage. GA significantly increased 8-oxodG formation in human cultured cells (HL-60), and H2O2 enhanced it. We conclude that oxidative DNA damage by hyperglycemia-related aldehydes, especially GA, and marked enhancement of DNA damage by H2O2 may participate in diabetes-associated carcinogenesis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Copper; Deoxyglucose; Deoxyguanosine; Diabetes Complications; DNA Damage; Drug Synergism; Glyceraldehyde; HL-60 Cells; Humans; Hydrogen Peroxide; Hyperglycemia; Neoplasms; Oxidation-Reduction

Hypohalites (OCl-, OBr-) are formed at inflammation sites as antimicrobial agents. OCl- is also used for the disinfection of water supplies and the association of drinking chlorinated water with cancer risk is pointed out. In this study, OCl- itself induced 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation, while OBr- damaged DNA only when glutathione (GSH) was added. OCl- caused oxidative DNA damage more efficiently than OBr-/GSH. In experiment with 32P-labeled DNA fragments, OCl- strongly caused piperidine-labile sites at guanine residues than piperidine-inert 8-oxodG, whereas OBr-/GSH caused no piperidine-labile sites. Endogenous OCl- may play a role in genotoxicity close to the site of inflammation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Bromates; Carcinogens; Cattle; Cell Line; Deoxyguanosine; Dimethyl Sulfoxide; DNA; DNA Damage; Electron Spin Resonance Spectroscopy; Genes, p53; Genes, ras; Genes, Tumor Suppressor; Glutathione; Humans; Inflammation; Neoplasms; Oxidation-Reduction; Phosphorus Isotopes; Piperidines; Sodium Hypochlorite

The present study was performed to investigate the relationship between work-related factors, including psychological stress, and the formation of a type of oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OH-dG), in order to examine their possible risk factor for occupational carcinogenesis.. A total of 54 healthy workers (27 male and 27 female, aged 41.2 +/- 12.5 years) in a company were investigated for 8-OH-dG levels in the peripheral blood leukocytes at the time of a questionnaire survey regarding several factors, such as working hours, workload, fatigue, sleep, psychological stress and the prospect of alleviating it. Subjects were limited to non-smoking and non-drinking workers to exclude the influence of cigarette smoking and alcohol drinking, which have been reported to have associations with the formation of 8-OH-dG.. The levels of 8-OH-dG in female subjects were significantly related to the perceived workload (F = 5.56, P = 0.010), the perceived psychological stress (F = 6.15, P = 0.007), and the impossibility of alleviating stress (F = 3.82, P = 0.048). No associations were observed in male subjects.. Psychological stress and perceived over-work appear to be related to the pathogenesis of cancer via the formation of 8-OH-dG, particularly in female workers.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Analysis of Variance; Biomarkers; Deoxyguanosine; DNA Damage; Female; Humans; Male; Middle Aged; Neoplasms; Occupational Diseases; Oxidative Stress; Risk; Statistics, Nonparametric; Stress, Psychological; Workload

Estrogens exert pro-oxidative effects and have been shown to damage DNA, potentially leading to cancer. Melatonin is a well-known antioxidant, free radical scavenger, and oncostatic agent. Changes in the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), an index of DNA damage, and the levels of malondialdehyde + 4-hydroxyalkenals, an index of lipid peroxidation, were measured in kidneys, liver, and testes from hamsters treated with E2 (75 mg/kg body wt) and were collected 3 or 5 hr later. Other animals were treated with melatonin (15 mg/kg body wt, 30 min before and 120 min after E2 treatment) or were given both compounds. Additionally, lipid peroxidation was measured in liver homogenates exposed to ferrous sulfate (15 microM) in vitro. E2 treatment caused an increase in 8-oxodGuo levels in kidneys collected 5 hr after E2 administration, and in liver 3 hr after estrogen treatment. Melatonin completely prevented E2-induced DNA damage in both organs. Melatonin alone or when given with E2 and examined 3 hr later decreased the base level of 8-oxodGuo in testes. A tendency for a reduction in in vivo lipid peroxidation was observed after treatment of hamsters with either melatonin, E2, or both compounds, with a statistically significant decrease being measured in the liver following E2 administration. In vitro exposure to iron significantly enhanced lipid peroxidation in hepatic homogenates from untreated, melatonin-treated, or E2-injected hamsters; in the hepatic homogenates of hamsters given both E2 and melatonin, ferrous sulfate failed to augment lipid peroxidation. Our results confirm the dual actions of estrogens relative to oxidative damage, i.e., estrogen increases oxidative destruction of DNA while reducing lipid peroxidation. Melatonin had antioxidative actions in reducing oxidative damage to both DNA and to membrane lipids. Melatonin completely prevented the damaging action of E2 on DNA and synergized with the steroid to reduce lipid peroxidation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cricetinae; Deoxyguanosine; DNA Damage; Estradiol; Kidney; Lipid Peroxidation; Liver; Male; Malondialdehyde; Melatonin; Mesocricetus; Neoplasms; Oxidants; Testis

In the preceding paper [B. Marczynski, P. Rozynek, T. Kraus, St. Schlösser, H.J. Raithel, X. Baur, Levels of 8-hydroxy-2'-deoxyguanosine in DNA of white blood cells from workers highly exposed to asbestos in Germany, Mutat. Res. (2000) submitted] we described significant increases (p<0.001) in the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) adducts in the DNA of white blood cells (WBC) of workers highly exposed to asbestos fibers at the workplace relative to those found in the control group in all three study years (period between 1994 and 1997). The results show that the oxidative DNA damage in exposed individuals is between 1.7 times and twice that found in control samples for all 3 years of the study (p<0.001). The aim of this study was to examine the association between the 8-OHdG levels in WBC DNA of workers highly exposed to asbestos fibers at the workplace and clinical data, occupational and non-occupational confounding factors, and cancer. There is no obvious correlation between the steady-state levels of 8-OHdG in the circulating WBC DNA of asbestos workers and possible confounding factors, such as the presence of benign asbestos-associated diseases, the duration of asbestos exposure, the latency period, the fixed cumulative fibrous dust dose ("fiber years"), age, smoking status, acute febrile infections, medicines, aspirin, calcium (Ca(2+)), magnesium (Mg(2+)), and the hormone and vitamin intake. This indicates that previous inhalation of asbestos fibers is the major factor responsible for the difference observed in oxidative DNA damage between asbestos workers and controls. For patients suffering from respiratory cancer, cancer of the gastrointestinal tract, mouth/pharynx/larynx, and urogenital tract the mean DNA-adduct level was significantly higher (p<0.01) than that found in controls, but not significantly higher (p>0.05) than that for asbestos-exposed patients without tumours. The formation of 8-OHdG adduct levels in WBC DNA of patients with hematopoietic cancer, chondrosarcomas and multiform glioblastomas was not significantly higher than that found in the control group (p>0.05). Our results support the hypothesis that oxidative DNA damage in man caused by asbestos fibers plays a role in the formation of malignant tumours.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adolescent; Adult; Aged; Asbestos; Asbestos, Serpentine; Biomarkers; Calcium, Dietary; Confounding Factors, Epidemiologic; Deoxyguanosine; DNA Adducts; DNA Damage; Dust; Female; Germany; Hormones; Humans; Infections; Leukocytes; Magnesium; Male; Middle Aged; Neoplasms; Occupational Diseases; Occupational Exposure; Organ Specificity; Oxidative Stress; Pharmaceutical Preparations; Reactive Oxygen Species; Risk Factors; Smoking; Vitamins

Arsenic is widely distributed in nature in the form of either metalloids or chemical compounds, which cause a variety of pathologic conditions including cutaneous and visceral malignancies. Recently, reactive oxygen species have been hypothesized to be one of the causes of arsenic-induced carcinogenesis. 8-Hydroxy-2'-deoxyguanosine is one of the major reactive oxygen species-induced DNA base-modified products that is widely accepted as a sensitive marker of oxidative DNA damage. We studied the presence of 8-hydroxy-2'-deoxyguanosine by immunohistochemistry using N45.1 monoclonal antibody in 28 cases of arsenic-related skin neoplasms and arsenic keratosis as well as in 11 cases of arsenic-unrelated Bowen's diseases. The frequency of 8-hydroxy-2'-deoxyguanosine positive cases was significantly higher in arsenic-related skin neoplasms (22 of 28; 78%) than in arsenic-unrelated Bowen's disease (one of 11; 9%) (p < 0.001 by chi2 test). 8-Hydroxy-2'-deoxyguanosine was also detected in normal tissue adjacent to the arsenic-related Bowen's disease lesions. Furthermore, arsenic was detected by neutron activation analysis in the deparaffined skin tumor samples of arsenic-related disease (four of five; 80%), whereas arsenic was not detected in control samples. Our results strongly suggest the involvement of reactive oxygen species in arsenic-induced human skin cancer. Key word: neutron activation analysis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Aged, 80 and over; Arsenic; Bowen's Disease; Deoxyguanosine; DNA Damage; Female; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasms; Neutron Activation Analysis; Oxidative Stress; Poisons; Reactive Oxygen Species; Skin; Skin Neoplasms

Various markers of radiation-induced DNA damage including DNA oxidation were investigated in peripheral lymphocytes of 23 cancer patients prior to and one week after receiving radiotherapy with a cumulative dose of 54-70 Gy. Exposure to ionizing radiation nonsignificantly increased the ratio 2'deoxy-7-dihydro-8-oxoguanosine/2'deoxyguanosine (8-oxodG/dG) from 1.73 x 10(-5) to 3.33 x 10(-5). Frequencies of micronuclei significantly (p = 0.0003) increased from 6.4 to 38.9 per 1000 cells. The frequency of hypoxanthine-guanine-phosphoribosyltransferase (HPRT) mutant lymphocytes measured as 6-thioguanine resistant variant cells by 5-bromodeoxyuridine labeling, was elevated eight-fold, from 4.7 x 10(-6) to 36.2 x 10(-6) (p = 0.008) after termination of the radiotherapy, thus showing a clear response to the radiation treatment. No correlation between levels of oxidative DNA damage and frequencies of HPRT mutant lymphocytes or micronuclei could be established.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Aged, 80 and over; Antioxidants; Biomarkers; Breast Neoplasms; Bromodeoxyuridine; Deoxyguanosine; DNA Damage; Female; Head and Neck Neoplasms; Humans; Hypoxanthine Phosphoribosyltransferase; Male; Micronucleus Tests; Middle Aged; Neoplasms; Oxidation-Reduction; Prostatic Neoplasms; Smoking

Environmental tobacco smoke (ETS) is a pervasive contaminant in the workplace. Our objective was to determine the oxidative stress effects of ETS on employees who are exposed. The results provide information that is useful to the resolution of risk assessment questions associated with ETS. We analyzed two blood draws from volunteers in our control and exposed groups. The level of exposure to ETS was determined through plasma cotinine measurements, which showed a 65% increase from the control group to the exposed group. Exposure to ETS resulted in a statistically significant increase of 63% of the oxidative DNA mutagen 8-hydroxy-2'-deoxyguanosine in the blood of exposed subjects. This oxidative DNA damage has been linked to an increased risk of developing several degenerative chronic diseases, including coronary heart disease and cancer. The exposed subjects also had increased levels of superoxide dismutase, catalase, glutathione peroxidase (GPOX), and glutathione reductase. However, these increases were only statistically significant in catalase and GPOX. Catalase levels were 13% higher in the exposed group, and GPOX levels were 37% higher in exposed volunteers. The biochemical evidence suggests that exposure to ETS causes oxidative stress, resulting in DNA damage that may increase the risk of certain diseases.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Air Pollution, Indoor; Ascorbic Acid; beta Carotene; Catalase; Coronary Disease; Cotinine; Deoxyguanosine; Female; Glutathione Reductase; Humans; Male; Middle Aged; Neoplasms; Oxidative Stress; Risk Factors; Superoxide Dismutase; Tobacco Smoke Pollution; Vitamin E; Workplace

We measured the base 5-(hydroxymethyl) uracil (HMUra) and the nucleoside 8-oxo-7,8-dehydro-2'-deoxyguanosine (8-oxo-dGuo) in urine of adriamycin-treated cancer patients. Adriamycin has been shown to generate oxygen free radicals by various mechanisms. HMUra and 8-oxo-dGuo are two known lesions of DNA, produced by oxygen free reaction on thymine and 2'-deoxyguanosine, respectively. HMUra was measured by GC-MS/isotopic dilution and 8-oxo-dGuo by HPLC/EC, both after prepurification by semipreparative HPLC. Here we report the results of a study involving 20 cancer patients treated with flash doses of ADR. We found that urine HMUra is significantly increased (HMUra (nmol/24h): 80.8 8.44 vs. 98.7+/-6.87; p < 0.01) 24h after administration of the drug, while 8-oxo-dGuo did not show any significant variation. Urine HMUra seems to be a suitable short-term marker of DNA alterations by oxygen free radicals.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Antibiotics, Antineoplastic; Deoxyguanosine; DNA; Doxorubicin; Female; Humans; Male; Neoplasms; Oxidation-Reduction; Pentoxyl; Thiobarbituric Acid Reactive Substances

Extreme exercise increases oxygen uptake with a potential for increased formation of reactive oxygen species. Damage to biomolecules may occur if such an increase exceeds the protective capacity of antioxidant defence mechanisms. Vigorous exercise amounting to approximately 10 h a day for 30 days increased the rate of oxidative DNA modification by 33% (95% confidence limits, 3-67%; P < 0.02) in 20 men owing to the urinary excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine, an oxidatively modified deoxynucleoside originating from nuclear DNA repair, oxidation of the nucleotide pool from mitochondrial DNA and/or from cell turnover. Oxidative stress to DNA points to a risk for the development of cancer and premature ageing from extreme exercise.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aging; Antioxidants; Creatinine; Deoxyguanosine; DNA; DNA Damage; DNA Repair; DNA, Mitochondrial; Exercise; Humans; Male; Neoplasms; Oxidation-Reduction; Oxidative Stress; Oxygen Consumption; Reactive Oxygen Species; Risk Factors

Mutators are cells that have a higher mutation rate than the wild type. Such mutators have been extensively studied in bacteria, and this has led to the elucidation of a number of important DNA repair pathways, as well as revealing new pathways of mutagenesis. Repair defects in humans that lead to mutator phenotypes are responsible for a number of cancer susceptibilities. In some cases, these repair systems are the close counterparts of the equivalent bacterial repair system. Therefore, characterizing bacterial mutators and the repair systems that are deficient can aid in discovering the human homolog of these systems.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Deoxyguanosine; DNA Repair; Enterobacteriaceae; Genes, Bacterial; Humans; Mutagenesis; Neoplasms; Oxidation-Reduction; Reactive Oxygen Species; RNA, Transfer

Previous epidemiological studies have indicated that industrial art glass workers have increased mortality risks for certain types of cancer and for cardio- and cerebrovascular disease. To test the hypothesis that increased oxidative stress might contribute to these increased mortality risks, the urinary levels of the lipid peroxidation product, malondialdehyde (MDA), and the oxidative DNA adduct, 8-hydroxydeoxyguanosine (8OHdG) were determined in 343 workers (230 men and 113 women) from the art glass industry in the southeast of Sweden. Of the study subjects, 199 (181 men and 18 women) were engaged in the process of glass production and were regarded as exposed, whereas the remainders performed clerical, warehouse and other service work and were regarded as unexposed. One hundred and sixteen were smokers (75 men and 41 women) and 215 were non-smokers (142 men and 73 women). The findings indicate that (a) exposure to industrial art glass work per se does not cause any major oxidative stress as measured by urinary levels of MDA and 8OHdG, (b) the effects from smoking per se are limited to increased lipid peroxidation among men, and (c) joint exposure to industrial art glass work and smoking may cause increased lipid peroxidation among men and increased DNA hydroxylation among both men and women. While these findings provide no evidence for increased oxidative stress due to industrial art glass work per se, the increased 8OHdG excretion, in workers who smoke may be associated with a higher risk of developing free radical-dependent degenerative diseases including cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Art; Biomarkers; Case-Control Studies; Deoxyguanosine; Environmental Monitoring; Female; Glass; Humans; Male; Malondialdehyde; Middle Aged; Neoplasms; Occupational Diseases; Oxidative Stress; Smoking

An automated analytical method has been developed for determination of the oxidative DNA adduct, 8-hydroxydeoxyguanosine (8OHdG) in human urine, based on coupled-column high performance liquid chromatography with electrochemical detection. Urine is concentrated on Bondelut CH by means of an automated sample processor, and the enriched sample injected on to a polymeric reversed phase column coupled in line with an electrochemical detector and a C18 reversed phase column. By use of the electrochemical detector, a suitable retention time interval is set for collection of the fraction containing 8OHdG from the chromatography on the first column; this fraction is collected in a 2 mL loop and injected onto the C18 column. The system is operated by an automatic valve station controlled by an integrator. The method has a large sample capacity and measures 31.1, 15.7, and 7.43 nmol 8OHdG/L urine with variation coefficients of 8, 8 and 24% within series and 8, 11 and 23% between series. Normal healthy individuals were found to excrete 14.9 +/- 7.8 nmol 8OHdG/24 h, or 1.11 +/- 0.62 mumol 8OHdG per mol creatinine, in their urine, whereas increased levels of 8OHdG were found in 24 h collections from a variety of cancer patients, both in samples taken before onset of oncological therapy (1.84 +/- 1.12 mumol/mol creatinine, P < 0.01 versus healthy individuals) and after therapy onset (2.18 +/- 1.44 mumol/mol creatinine, P < 0.001 versus healthy individuals). Moreover, mean values of 8OHdG in random urinary samples from cancer patients were significantly higher than from healthy individuals (2.42 +/- 2.28 versus 1.19 +/- 0.48 mumol/mol creatinine, P < 0.001), both in samples taken before therapy onset (1.91 +/- 0.96, P < 0.001 versus healthy individuals) and after (2.57 +/- 2.46, P < 0.001 versus healthy individuals). High levels of urinary 8OHdG were found in patients subjected to whole body irradiation, and in patients receiving chemotherapy with various cytostatic agents. The potential use of the method for detecting increased urinary 8OHdG excretion and conditions associated with increased oxidative DNA damage in humans is discussed.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Antineoplastic Agents; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Electrochemistry; Female; Humans; Male; Middle Aged; Neoplasms; Random Allocation; Sensitivity and Specificity; Whole-Body Irradiation

Oxidative damage to DNA has been suggested to contribute to a number of diseases including cancer. In order to study the relationship between oxidative damage to DNA and occupational exposures, urinary excretion of the oxidative DNA adduct, 8-hydroxydeoxyguanosine (8-OHdG), was determined in asbestos workers, rubber workers, azo-dye workers and controls. Levels of 8-OHdG in urinary samples were quantified by automated coupled-column high-performance liquid chromatography with electrochemical detection (HPLC-EC). The registered 8-OHdG levels were 1.40 +/- 0.56 mumol/mol creatinine in asbestos workers, 1.48 +/- 0.57 in rubber workers, 1.92 +/- 0.85 in azo-dye workers and 1.07 +/- 0.41 in controls (means +/- SD). Thus, 8-OHdG levels appeared to be significantly higher (p < 0.05) in each of the exposed groups than in the control group. Regression analysis revealed no important association between 8-OHdG excretion, age and smoking. These findings suggest that occupational exposures may contribute to an increased oxidative damage to human DNA and point to the possible use of urinary 8-OHdG assays in biomonitoring of biological effects of chemicals in selected industrial workplaces.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Asbestos; Biomarkers; Chemical Industry; Deoxyguanosine; Female; Humans; Industry; Male; Middle Aged; Neoplasms; Occupational Exposure; Rubber

Many uncertainties remain about the free-radical theory of ageing and the role of oxidative damage to DNA in cancer. The chemistry and biochemistry of radical-induced DNA damage are now well characterized in vitro, but the complexity of in-vivo systems leaves this area still largely unexplored. Measurement of thymine and thymidine glycols in urine may be a means of assaying background levels of radical-induced DNA damage in live organisms. Similar approaches may prove useful for testing some of the predictions of the free-radical theory of ageing and of the contribution of free radicals to cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Antioxidants; Deoxyguanosine; DNA Damage; Free Radicals; Humans; Lipid Peroxides; Neoplasms; Oxidation-Reduction