Background & Aims: Cells of tumors associated with chronic inflammation frequently have altered patterns of DNA methylation, including hepatocellular carcinomas. Chronic hepatitis has also been associated with aberrant DNA methylation, but little is known about their relationship.
Methods: Pyrosequencing was used to determine the methylation status of cultured Huh7.5.1 hepatoma cells after hepatitis C virus (HCV) infection. We also studied mice with severe combined immunodeficiency carrying the urokinase-type plasminogen activator transgene controlled by an albumin promoter (urokinase-type plasminogen activator/severe combined immunodeficient mice), in which up to 85% of hepatocytes were replaced by human hepatocytes (chimeric mice). Mice were given intravenous injections of hepatitis B virus (HBV) or HCV, liver tissues were collected, and DNA methylation profiles were determined at different time points after infection. We also compared methylation patterns between paired samples of hepatocellular carcinomas and adjacent nontumor liver tissues from patients.
Results: No reproducible changes in DNA methylation were observed after infection of Huh7.5.1 cells with HCV. Livers from HBV- and HCV-infected mice had genome-wide, time-dependent changes in DNA methylation, compared with uninfected urokinase-type plasminogen activator/severe combined immunodeficient mice. There were changes in 160 ± 63 genes in HBV-infected and 237 ± 110 genes in HCV-infected mice. Methylation of 149 common genes increased in HBV- and HCV-infected mice; methylation of some of these genes also increased in hepatocellular carcinoma samples from patients compared with nontumor tissues. Expression of Ifng, which is expressed by natural killer cells, increased significantly in chimeric livers, in concordance with induction of DNA methylation, after infection with HBV or HCV. Induction of Ifng was reduced after administration of an inhibitor of natural killer cell function (anti-asialo GM1).
Conclusions: In chimeric mice with humanized livers, infection with HBV and HCV appears to activate a natural kill cell-dependent innate immune response. This contributes to the induction and accumulation of aberrant DNA methylation in human hepatocytes.
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http://dx.doi.org/10.1053/j.gastro.2013.10.056 | DOI Listing |
Sci Rep
January 2025
Office of Research and Development, United States Environmental Protection Agency, 104 Mason Farm Rd., Chapel Hill, NC, 27514, USA.
Potential pathways linking urban green spaces to improved health include relaxation, stress alleviation, and improved immune system functioning. Epigenetic age acceleration (EAA) is a composite biomarker of biological aging based on DNA methylation measurements; it is predictive of morbidity and mortality. This cross-sectional study of 116 adult residents of a metropolitan area in central North Carolina investigated associations between exposure to residential green spaces and EAA using four previously developed epigenetic age formulas.
View Article and Find Full Text PDFCell Death Discov
January 2025
Laboratory of Genome Stress Signaling, National Cancer Center Research Institute, Chuo-ku, Tokyo, 104-0045, Japan.
DNA replication stress (RS), a prevalent feature of various malignancies, arises from both genetic mutations and genotoxic exposure. Elevated RS levels increase the vulnerability of cancer cells to ataxia telangiectasia and Rad3-related kinase inhibitors (ATRis). Here, we screened for DNA damage response inhibitors that enhance ATRi-induced cytotoxicity using SWI/SNF complex-deficient cells and identified a potent synergy between ATRi and poly(ADP-ribose) polymerase inhibitor (PARPi), particularly in SMARCA4-deficient cells.
View Article and Find Full Text PDFClin Chim Acta
January 2025
Department of Urology, The People's Hospital of Qingyang City/Qingyang Hospital of the Second Hospital of Lanzhou University, Qingyang 745000 China. Electronic address:
Background: Urothelial carcinoma (UC) is a common malignancy worldwide. Aberrant DNA methylation is implicated in UC carcinogenesis. This study sought to delineate the DNA methylation landscape in UC and identify DNA methylation-based biomarkers for early detection of UC.
View Article and Find Full Text PDFGene
January 2025
Department of Maternal and Child Health School of Public Health Tongji Medical College Huazhong University of Science and Technology Wuhan China; Key Laboratory of Environment and Health, Ministry of Education and Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, Hubei 430030, China. Electronic address:
Background: Existing epigenome-wide association study (EWAS) investigating the association between DNA methylation (DNAm) and child neurodevelopment have been predominantly conducted within Western populations, and yielded inconsistent results, leading to a significant gap within non-Western setting, particularly in resource-limited rural areas of Central China.
Objectives: To investigate the association between altered epigenome-wide DNAm and neurodevelopment in preschool children from resource-limited rural areas of Central China.
Methods: This case-control study involved 64 preschoolers.
DNA Repair (Amst)
January 2025
Cancer Cytogenomic Laboratory, Center for Research and Drug Development (NPDM), Federal University of Ceara, Fortaleza, Ceara, Brazil; Post-Graduate Program in Medical Science, Federal University of Ceara, Fortaleza, Ceara, Brazil; Post-Graduate Program of Pathology, Federal University of Ceara, Fortaleza, Ceara, Fortaleza, Ceara, Brazil; Post-Graduate Program of Translational Medicine, Federal University of Ceara, Fortaleza, Ceara, Brazil.
Myelodysplastic Neoplasm (MDS) is a cancer associated with aging, often leading to acute myeloid leukemia (AML). One of its hallmarks is hypermethylation, particularly in genes responsible for DNA repair. This study aimed to evaluate the methylation and mutation status of DNA repair genes (single-strand - XPA, XPC, XPG, CSA, CSB and double-strand - ATM, BRCA1, BRCA2, LIG4, RAD51) in MDS across three patient cohorts (Cohort A-56, Cohort B-100, Cohort C-76), using methods like pyrosequencing, real-time PCR, immunohistochemistry, and mutation screening.
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