8-hydroxy-2--deoxyguanosine and Hepatitis-C

Oxidative DNA damage occurs as an early event in hepatitis C virus (HCV) infection and is an indication of the potential for carcinogenesis. The aim of this study was to test a novel antioxidant/immunomodulator in patients with HCV-related cirrhosis.. The study group consisted of 50 patients with HCV-related cirrhosis with transaminase values less than twofold increased (alanine aminotransferase [ALT] < 80 IU/L). Patients underwent a standardized food-vitamin composition assessment and were assessed for dietary intake, nutritional status and iron level. Patients were randomly allocated into two groups and then given either alpha-tocopherol 900 IU/day or 9 g/day of a fermented papaya preparation (FPP, Immun-Age, Osato Research Institute, Gifu, Japan) at bedtime for 6 months. Ten healthy subjects served as controls. Patients were checked monthly for: routine tests, redox status (reduced glutathione, glutathione peroxidase, oxidized glutathione, malondialdehyde), plasma alpha-tocopherol, 8-hydroxy-deoxy-guanidine (8-OHdG) level in circulating leukocyte DNA and serum levels of cytokines.. Patients with cirrhosis showed a significant imbalance of redox status (low antioxidants/high oxidative stress markers) (P < 0.005 vs controls). Neither treatment regimen affected transaminases as a whole. However, vitamin E supplementation almost normalized ALT only in the limited vitamin-E-deficient subgroup. A significant improvement of redox status was obtained by both regimens. However, only FPP significantly decreased 8-OHdG and the improvement of cytokine balance with FPP was significantly better than with vitamin E treatment (P < 0.05).. Although the present data seem to suggest a potential supportive role of antioxidants/immunomodulators as FPP in HCV patients, more studies are needed to substantiate their effect on the natural history of the disease.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Alanine Transaminase; alpha-Tocopherol; Antioxidants; Carica; Deoxyguanosine; DNA Damage; Female; Fermentation; Fruit; Glutathione; Glutathione Peroxidase; Hepatitis C; Humans; Immunologic Factors; Liver Cirrhosis; Male; Middle Aged; Oxidation-Reduction; Oxidative Stress; Plant Preparations; Receptors, Tumor Necrosis Factor, Type II; Severity of Illness Index; Treatment Outcome; Tumor Necrosis Factor-alpha

Molecular mechanisms underlying Hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) pathogenesis are still unclear. Therefore, we analyzed the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and other oxidative lesions at codon 176 of the p53 gene, as well as the generation of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M

Topics: 8-Hydroxy-2'-Deoxyguanosine; Carcinoma, Hepatocellular; Cell Line, Tumor; Codon; Cytosine; DNA Adducts; Genes, p53; Hep G2 Cells; Hepacivirus; Hepatitis C; Humans; Lipid Peroxidation; Liver Neoplasms; Polymerase Chain Reaction; Reactive Oxygen Species

In viral hepatitis, inflammation is correlated with chronic oxidative stress, one of the biological events leading to DNA damage and hepatocellular carcinoma (HCC) development. Aim of this study was to investigate the complex molecular network linking oxidative damage to telomere length and telomerase activity and regulation in hepatitis C and B virus-related liver carcinogenesis. We investigated 142 patients: 21 with HCC (in both tumor and peritumor tissues) and 121 with chronic viral hepatitis in different stages. We evaluated 8-hydroxydeoxyguanosine (8-OHdG), marker of oxidative DNA damage, OGG1 gene polymorphism, telomere length, telomerase activity, TERT promoter methylation, and mitochondrial TERT localization. In hepatitis C-related damage, 8-OHdG levels increased since the early disease stages, whereas hepatitis B-related liver disease was characterized by a later and sharper 8-OHdG accumulation (P = 0.005). In C virus-infected patients, telomeres were shorter (P = 0.03), whereas telomerase activity was higher in tumors than that in the less advanced stages of disease in both groups (P = 0.0001, P = 0.05), with an earlier increase in hepatitis C. Similarly, TERT promoter methylation was higher in tumor and peritumor tissues in both groups (P = 0.02, P = 0.0001). Finally, TERT was localized in mitochondria in tumor and peritumor samples, with 8-OHdG levels significantly lower in mitochondrial than those in genomic DNA (P = 0.0003). These data describe a pathway in which oxidative DNA damage accumulates in correspondence with telomere shortening, telomerase activation, and TERT promoter methylation with a different time course in hepatitis B and C virus-related liver carcinogenesis. Finally, TERT localizes in mitochondria in HCC, where it lacks a canonical function.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Carcinogenesis; Deoxyguanosine; DNA Damage; DNA Glycosylases; DNA, Mitochondrial; Gene Expression Regulation, Neoplastic; Hepacivirus; Hepatitis B; Hepatitis B virus; Hepatitis C; Humans; Liver Neoplasms; Oxidation-Reduction; Polymorphism, Genetic; Telomerase; Telomere Shortening

This study evaluated the relationship between inflammation, intra-hepatic oxidative stress, oxidative DNA damage and the progression of liver carcinogenesis in hepatitis C virus (HCV)-infected humans.. Non-cancerous liver tissues were collected from 30 patients with an HCV-associated solitary hepatocellular carcinoma (HCC) who received curative tumor removal. After surgery, the patients were followed at monthly intervals at the outpatient clinic. Distribution of the inflammatory cells (CD68+), the number of 8-hydroxydeoxyguanosine (8-OHdG) DNA adducts and 4-hydroxynonenal (HNE) protein adducts and the expression of apurinic/apyrimidinic endonuclease (APE) were determined by immunohistochemical analysis in serial liver sections from tumor-free parenchyma at the surgical margin around the tumor.. Significant positive correlations were observed between the number of CD68+ cells, the amount of HNE protein adducts, and the number of 8-OHdG adducts in liver tissue of patients with HCC and HCV. The cumulative disease-free survival was significantly shorter in patients with the highest percentage of 8-OHdG-positive hepatocytes. Using a Cox proportional hazard model, 8-OHdG, HNE and CD68 were determined to be good biomarkers for predicting disease-free survival in patients with HCC and HCV.. These results support the hypothesis that HCV-induced inflammation causes oxidative DNA damage and promotes hepatocarcinogenesis which directly affects the clinical outcome. Since patients with greater intra-hepatic oxidative stress had a higher incidence of HCC recurrence, we suggest that oxidative stress biomarkers could potentially be used as a useful clinical diagnostic tool to predict the duration of disease-free survival in patients with HCV-associated HCC.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Alanine Transaminase; Aldehydes; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Biomarkers, Tumor; Carcinoma, Hepatocellular; Deoxyguanosine; DNA Adducts; DNA Damage; Female; Follow-Up Studies; Hepacivirus; Hepatectomy; Hepatitis C; Humans; Inflammation; Lipid Peroxidation; Liver Neoplasms; Male; Microfilament Proteins; Middle Aged; Neoplasm Recurrence, Local; Oxidative Stress; Prognosis; Reactive Oxygen Species; Risk Factors; Survival Rate; Vesicular Transport Proteins

Posttransplant diabetes mellitus (PTDM) is common after liver transplantation and was recently identified as a risk factor for hepatitis C progression. Increased levels of oxidative stress have been identified in diabetes and hepatitis C. The aim of this study was to evaluate the relationship among PTDM, oxidative damage in liver biopsy specimens, and fibrosis progression posttransplant.. Subjects consisted of 27 hepatitis C-infected liver transplant recipients who had liver biopsy specimens available from 49 protocol liver biopsies. Paraffin embedded liver tissue sections were stained for 8-hydroxy-2' deoxyguanosine (8-OHdG), an indicator of hydroxyl radical mediated tissue damage. The percentage of cells staining for 8-OHdG in a histologic section was categorized as high (>66%) versus low score (< or =66%). Fibrosis index was calculated as fibrosis score (0-4)/ years posttransplant. Time to bridging fibrosis or cirrhosis (F3-4) was compared as a function of PTDM and 8-OHdG score.. Considering all 49 biopsies, fibrosis index was higher in cases with PTDM (P<0.001) and high 8-OHdG score (P=0.004). High 8-OHdG score was associated with PTDM (P=0.012). In time to event analyses, time to F3-4 was more rapid in patients with PTDM (P=0.02) and in those with high 8-OHdG scores (P<0.001).. This study confirmed a relationship between PTDM and hepatitis C fibrosis progression and found that oxidative damage in liver biopsy specimens was associated with PTDM and more rapid development of advanced fibrosis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biopsy; Deoxyguanosine; Diabetes Mellitus; Disease Progression; Female; Hepatitis C; Humans; Liver Cirrhosis; Liver Transplantation; Male; Middle Aged; Oxidative Stress; Survival Rate; Time Factors

Oxidative DNA damage, identifiable in the formation of 8-hydroxydeoxyguanosine (8-OHdG), is relevant in the mutagenesis/carcinogenesis process. The aim of this study was to assess 8-OHdG levels in patients with hepatitis C virus (HCV) infection in relation to extent of liver damage and HCV genotype.. 8-OHdG levels were measured in DNA from circulating leukocytes of 110 anti-HCV positive subjects belonging to the population of the Dionysos study, subgrouped in: 50 anti-HCV+ with persistently normal ALT, 48 with chronic hepatitis and 12 with cirrhosis. Twenty normal subjects served as Controls. 8-OHdG levels were assayed by HPLC/electrochemical detector.. 8-OHdG levels rose (P < 0.00001) from Controls to HCV+; chronic hepatitis and cirrhosis were associated with a further increase (P < 0.02 versus HCV+). Genotype 1 was associated with higher levels of 8-OHdG (P < 0.04). Multiple logistic regression analysis showed that, after correction for potential confoundings, 8-OHdG levels correlated (P < 0.02) with presence and extent of liver damage.. An accumulation of 8-OHdG in circulating leukocytes is a reliable marker of the extent of liver damage in HCV+ patients and is present in particular in genotype 1 infection. This genomic damage may contribute to liver carcinogenesis by causing persistent DNA changes.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adolescent; Adult; Child; Deoxyguanosine; DNA; Female; Genotype; Hepacivirus; Hepatitis C; Humans; Leukocytes; Liver; Male; Middle Aged; Oxidative Stress; Reference Values; Severity of Illness Index