8-nitroguanine and Inflammation

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

Topics: Animals; Bacteria; Guanine; Humans; Immunity, Innate; Inflammation; Mutation; Neoplasms; Nitric Oxide; Reactive Nitrogen Species; Signal Transduction; Viruses

Infection and chronic inflammation are proposed to contribute to carcinogenesis through inflammation-related mechanisms. Infection with hepatitis C virus, Helicobacter pylori and the liver fluke, Opisthorchis viverrini (OV), are important risk factors for hepatocellular carcinoma (HCC), gastric cancer and cholangiocarcinoma, respectively. Inflammatory bowel diseases (IBDs) and oral diseases, such as oral lichen planus (OLP) and leukoplakia, are associated with colon carcinogenesis and oral squamous cell carcinoma (OSCC), respectively. We performed a double immunofluorescence labeling study and found that nitrative and oxidative DNA lesion products, 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), were formed and inducible nitric oxide synthase (iNOS) was expressed in epithelial cells and inflammatory cells at the site of carcinogenesis in humans and animal models. Antibacterial, antiviral and antiparasitic drugs dramatically diminished the formation of these DNA lesion markers and iNOS expression. These results suggest that oxidative and nitrative DNA damage occurs at the sites of carcinogenesis, regardless of etiology. Therefore, it is considered that excessive amounts of reactive nitrogen species produced via iNOS during chronic inflammation may play a key role in carcinogenesis by causing DNA damage. On the basis of our results, we propose that 8-nitroguanine is a promising biomarker to evaluate the potential risk of inflammation-mediated carcinogenesis.

Topics: Animals; Cholangiocarcinoma; Colonic Neoplasms; DNA Damage; Guanine; Humans; Infections; Inflammation; Inflammatory Bowel Diseases; Liver Neoplasms; Mice; Mouth Neoplasms; Neoplasms; Oxidative Stress

Nitric oxide (NO) and superoxide rapidly react to yield peroxynitrite. Peroxynitrite is a potent oxidant which reacts with proteins, lipids, and DNA. The present paper overviews the various DNA modifications induced by exposure to peroxynitrite or NO and superoxide concurrently, with special reference to the formation of 8-nitroguanine and 8-oxoguanine as well as the induction of DNA single strand breakage. In addition, we review the secondary processes that may follow the process of DNA damage, such as activation of the nuclear enzyme, poly(ADP-ribose) synthetase, apoptosis, and carcinogenesis.

Topics: Animals; Apoptosis; Cell Transformation, Neoplastic; DNA; DNA Damage; Guanine; Humans; Inflammation; Nitrates; Nitric Oxide; Oxidants; Poly(ADP-ribose) Polymerases; Superoxides

Nitrative and oxidative DNA damage plays an important role in inflammation-related carcinogenesis. Chronic inflammation such as parasite infection and primary sclerosing cholangitis can be an etiological factor of cholangiocarcinoma. Using a proteomic approach and double-fluorescent staining, we identified high expression and colocalization of albumin and cytokeratin-19 in liver fluke-associated cholangiocarcinoma tissues, compared with normal livers from cholangiocarcinoma patients and cadaveric donors, respectively. Albumin was detected not only in cells of hyperplastic bile ducts and cholangiocarcinoma, but also in liver stem/progenitor cell origin, such as canal of Hering, ductules, and ductular reactions, suggesting the involvement of stem/progenitor cells in cholangiocarcinoma development. To clarify the involvement of liver stem/progenitor cells in cholangiocarcinoma, we examined several stem/progenitor cell markers (CD133, CD44, OV6, and Oct3/4) in cholangiocarcinoma tissues analyzed by immunohistochemical staining, and measured 8-oxodG levels by using HPLC-ECD as an inflammation-related DNA lesion. In addition, a stem/progenitor cell factor Bmi1, 8-nitroguanine (formed during nitrative DNA damage), DNA damage response (DDR) proteins (phosphorylated ATM and γ-H2AX), and manganese-SOD (Mn-SOD) were analyzed by immunohistochemistry. Stem/progenitor cell markers (CD133, OV6, CD44, and Oct3/4) were positively stained in 56, 38, 47, and 56% of 34 cholangiocarcinoma cases, respectively. Quantitative analysis of 8-oxodG revealed significantly increased levels in CD133- and/or Oct3/4-positive tumor tissues compared to negative tumor tissues, as well as 8-nitroguanine formation detected by immunohistochemistry. In the cases of CD44- and/or OV6-positive tissue, no significant difference was observed. Cholangiocarcinoma patients with CD133- and/or Oct3/4-positive tumor tissues showed significantly lower expression of Mn-SOD and higher DDR protein, γ-H2AX. Moreover, CD133- and/or Oct3/4-positive cholangiocarcinoma patients had significant associations with tumor histology types, tumor stage, and poor prognoses. Our results suggest that CD133 and Oct3/4 in cholangiocarcinoma are associated with increased formation of DNA lesions and the DDR protein, which may be involved in genetic instability and lead to cholangiocarcinoma development with aggressive clinical features.

Topics: 8-Hydroxy-2'-Deoxyguanosine; AC133 Antigen; Albumins; Antigens, CD; Antigens, Differentiation; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cell Transformation, Neoplastic; Cholangiocarcinoma; Cholangitis, Sclerosing; Deoxyguanosine; DNA Damage; DNA Repair; Female; Genomic Instability; Glycoproteins; Guanine; Histones; Humans; Hyaluronan Receptors; Inflammation; Keratin-19; Liver; Male; Middle Aged; Octamer Transcription Factor-3; Oxidation-Reduction; Peptides; Polycomb Repressive Complex 1; Prognosis; Stem Cells; Superoxide Dismutase

Carbon nanotube (CNT) has a promising usage in the field of material science for industrial purposes because of its unique physicochemical property. However, intraperitoneal administration of CNT was reported to cause mesothelioma in experimental animals. Chronic inflammation may contribute to carcinogenesis induced by fibrous materials. 8-Nitroguanine is a mutagenic DNA lesion formed during inflammation and may play a role in CNT-induced carcinogenesis. In this study, we examined 8-nitroguanine formation in A549 human lung alveolar epithelial cells treated with multi-walled CNT (MWCNT) by fluorescent immunocytochemistry. Both MWCNTs with diameter of 20-30 nm (CNT20) and 40-70 nm (CNT40) significantly induced 8-nitroguanine formation at 5 and 10 μg/ml (p<0.05), which persisted for 24h, although there was no significant difference in DNA-damaging abilities of these MWCNTs. MWCNTs significantly induced the expression of inducible nitric oxide synthase (iNOS) for 24 h (p<0.05). MWCNTs also significantly increased the level of nitrite, a hydrolysis product of oxidized NO, in the culture supernatant at 4 and 8 h (p<0.05). MWCNT-induced 8-nitroguanine formation and iNOS expression were largely suppressed by inhibitors of iNOS (1400 W), nuclear factor-κB (Bay11-7082), actin polymerization (cytochalasin D), caveolae-mediated endocytosis (methyl-β-cyclodextrin, MBCD) and clathrin-mediated endocytosis (monodansylcadaverine, MDC). Electron microscopy revealed that MWCNT was mainly located in vesicular structures in the cytoplasm, and its cellular internalization was reduced by MBCD and MDC. These results suggest that MWCNT is internalized into cells via clathrin- and caveolae-mediated endocytosis, leading to inflammatory reactions including iNOS expression and resulting nitrative DNA damage, which may contribute to carcinogenesis.

Topics: Caveolae; Cell Line, Tumor; Cell Survival; Clathrin; DNA Damage; Endocytosis; Epithelial Cells; Flow Cytometry; Guanine; Humans; Immunohistochemistry; Inflammation; Lung; Microscopy, Electron, Transmission; Nanotubes, Carbon; NF-kappa B; Nitric Oxide Synthase Type II

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

Chronic inflammation is a recognized risk factor for human cancer at various sites because of persistent oxidative and nitrative tissue damage. Trp53+/- mice show the predisposition to tumor development, such as sarcomas and lymphomas, compared with Trp53+/+ mice. We investigated the effects of chronic inflammation, especially oxidative and nitrative stress, induced by subcutaneous implantation of a plastic plate (10 x 5 x 1 mm) as a foreign body on tumorigenesis in Trp53+/- and Trp53+/+ mice. The plastic plates were implanted at the age of about 11 weeks. Thirty out of 38 Trp53+/- mice (79%) developed sarcomas around the implant (mean time of tumor appearance was 45.8 +/- 12.0 weeks of age), whereas only one of 10 Trp53+/+ mice with an implant (10%) developed a tumor, at 56 weeks. No sarcomas developed at a sham-operation site. Two of 10 Trp53+/- mice with no implant (20%) also developed three sarcomas spontaneously at 77, 81 and 84 weeks. Increased immunostaining for markers of oxidative and nitrative stress (8-oxo-7,8-dihydro-2'-deoxyguanosine, 8-nitroguanine and 3-nitrotyrosine) and expression of inducible nitric oxide synthase in tumor cells and inflammatory cells were detected in implant-induced sarcomas compared with spontaneous sarcomas in Trp53+/- mice. Furthermore, p53 loss of heterozygosity was observed in 26 out of 29 implant-induced sarcomas (90%). These results indicate that implanted foreign bodies significantly enhanced sarcoma development in Trp53+/- mice, and this may be associated with increased oxidaive and nitrative stress. Loss of the remaining wild-type p53 allele and loss of p53 function appears to be, at least in part, underlying molecular mechanisms during the development of sarcomas at the implantation site in Trp53+/- mice. Such implant-induced sarcoma development in Trp53+/- mice could be useful for studying molecular mechanisms and developing new strategies for chemoprevention in human carcinogenesis induced by chronic inflammation and/or foreign bodies.

Topics: Animals; Foreign Bodies; Guanine; Humans; Inflammation; Loss of Heterozygosity; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide Synthase Type II; Oxidation-Reduction; Oxidative Stress; Sarcoma, Experimental; Tumor Suppressor Protein p53

Chronic inflammation is a critical component of carcinogenesis and tumor progression. Reactive nitrogen and oxygen species generated by inflammatory cells form mutagenic DNA lesions, such as 8-nitroguanine, which may play an integral role in inflammation-related carcinogenesis. Hypoxia-inducible factor (HIF)-1alpha has been established as a prognostic biomarker in various tumors, including malignant fibrous histiocytoma (MFH). The aim of this study was to evaluate the impact of 8-nitroguanine formation and HIF-1alpha expression on the prognosis of patients with inflammation-related cancer. Immunohistochemical analyses were employed to examine the distribution of 8-nitroguanine and HIF-1alpha, using clinical specimens from 36 patients with MFH as a model of inflammation-related cancer. 8-Nitroguanine formation was predominantly observed in the nuclei of tumor cells and inflammatory cells in tumor tissues, while HIF-1alpha was expressed in the cytoplasm and nuclei of tumor cells. Little or no immunoreactivity of 8-nitroguanine and HIF-1alpha was observed in adjacent non-tumor tissues. Significantly higher levels of both 8-nitroguanine and HIF-1alpha were observed in the tissue specimens of deceased patients than in those of living subjects. Survival curves analyzed by the Kaplan-Meier method differed significantly between the high- and low-staining groups of 8-nitroguanine (p=0.00003) as well as HIF-1alpha (p=0.01104). These results suggest a significant role of the pathway of iNOS-dependent 8-nitroguanine formation via HIF-1alpha and NF-kappaB on the progression of inflammation-related cancer. In conclusion, 8-nitroguanine is an excellent candidate prognostic and predictive biomarker together with HIF-1alpha in inflammation-related tumor progression.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Disease Progression; Female; Guanine; Histiocytoma, Malignant Fibrous; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Inflammation; Inflammation Mediators; Male; Middle Aged; NF-kappa B; Prognosis; Survival Rate

Nucleic acid damage by reactive nitrogen and oxygen species may contribute to inflammation-related carcinogenesis. To investigate the extent of nucleic acid damage in hepatitis C virus infection and its change after interferon treatment, we measured 8-nitroguanine and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the liver of patients with chronic hepatitis C (CHC) before and after interferon therapy.. Hepatic accumulation of 8-nitroguanine and 8-OHdG was immunohistochemically evaluated in 20 CHC patients and 7 control patients with non-alcoholic fatty liver.. Immunoreactivities of 8-nitroguanine and 8-OHdG were strongly detected in the liver from patients with CHC, but not in control livers. 8-Nitroguanine accumulation was found not only in infiltrating inflammatory cells, but also hepatocytes particularly in the periportal area. The accumulation of 8-nitroguanine and 8-OHdG increased with inflammatory grade (8-nitroguanine; P = 0.0019, 8-OHdG; P = 0.0009). In the sustained virological responder group after interferon therapy, 8-nitroguanine and 8-OHdG accumulation were markedly decreased in the liver (8-nitroguanine; P = 0.018, 8-OHdG; P = 0.018).. In this study, we demonstrated for the first time that 8-nitroguanine accumulated in the liver of patients with CHC. 8-Nitroguanine is a useful biomarker to evaluate the severity of HCV-induced chronic inflammation in relation to hepatocellular carcinoma.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Biomarkers; Carcinoma, Hepatocellular; Deoxyguanosine; DNA Damage; Female; Guanine; Hepatitis C, Chronic; Humans; Inflammation; Liver; Liver Neoplasms; Male; Middle Aged; Reactive Oxygen Species

NOx causes DNA damage due to an inflammatory effect of gouty arthritis. We investigated the concentration of 8-nitroguanine (8-NO(2)-G) in the blood of patients with arthritis.. Subjects were divided into 3 groups: (1) high inflammatory (HI) group (n = 21) with hyperuricemia (mean, 8.9 mg/dl) and leukocytosis, (2) low inflammatory (LI) group (n = 14) with mild hyperuricemia (mean, 7.6 mg/dl) but normal leukocyte count, (3) non-inflammatory (NI) healthy control (n = 19) with mean serum uric acid concentration 5.3 mg/dl and normal leukocyte count. Serum C-reactive protein (CRP) concentrations were measured by a visual agglutination method. The blood concentrations of 8-NO(2)-G were determined by high performance liquid chromatography-electrochemical detection and were compared between groups.. There was significant difference in percentage of positive CRP (NI: 55.6%, LI: 64.3%, HI: 100%, p = 0.003) between the 3 groups. The leukocyte count (mean +/- S.E., NI: 7400 +/- 528, LI: 7686 +/- 433, HI: 10952 +/- 691/mm(3), p < 0.001), uric acid (NI: 5.3 +/- 0.24, LI: 7.6 +/- 0.4, HI: 8.9 +/- 0.36 mg/dl, p < 0.001), NO(2) (NI: 6.5 +/- 1.2, LI: 11.1 +/- 2.9, HI: 35.6 +/- 5.1 microg/ml, p < 0.001) and the 8-NO(2)-G (NI: 0.08 +/- 0.03; LI: 0.34 +/- 0.13; HI: 0.59 +/- 0.09 ng/microg DNA, p = 0.002) were significantly increased by inflammation.. Gouty inflammation induces DNA damage by increasing 8-NO(2)-G through endogenous NO and ROS formation.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Arthritis, Gouty; C-Reactive Protein; Chromatography, High Pressure Liquid; DNA; Female; Guanine; Humans; Inflammation; Leukocyte Count; Male; Middle Aged; Nitrates; Uric Acid

Inflammation mediated by infection is an important factor causing carcinogenesis. Opisthorchis viverrini (OV) infection is a risk factor of cholangiocarcinoma (CHCA), probably through chronic inflammation. Formation of 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), and expression of inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1) were assessed in the liver of hamsters infected with OV. We newly produced specific anti-8-nitroguanine antibody without cross-reaction. Double immunofluorescence staining revealed that 8-oxodG and 8-nitroguanine were formed mainly in the same inflammatory cells and epithelium of bile ducts from day 7 and showed the strongest immunoreactivity on days 21 and 30, respectively. It is noteworthy that 8-oxodG and 8-nitroguanine still remained in epithelium of bile ducts on day 180, although amount of alanine aminotransferase activity returned to normal level. A time course of 8-nitroguanine was associated with iNOS expression. Furthermore, this study demonstrated that HO-1 expression and subsequent iron accumulation may be involved in enhancement of oxidative DNA damage in epithelium of small bile ducts. In conclusion, nitrative and oxidative DNA damage via iNOS expression in hamsters infected with OV may participate in CHCA carcinogenesis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cholangiocarcinoma; Cricetinae; Deoxyguanosine; Disease Models, Animal; DNA Damage; Gene Expression Regulation; Guanine; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Inflammation; Liver; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Opisthorchiasis; Opisthorchis; Oxidation-Reduction