1 5555 124 ROLE OF FLUORIDE INDUCED EPIGENETIC ALTERATIONS IN THE DEVELOPMENT OF SKELETAL FLUOROSIS. FLUORIDE IS AN ESSENTIAL TRACE ELEMENT REQUIRED FOR PROPER BONE AND TOOTH DEVELOPMENT. SYSTEMIC HIGH EXPOSURE TO FLUORIDE THROUGH ENVIRONMENTAL EXPOSURE (DRINKING WATER AND FOOD) MAY RESULT IN TOXICITY CAUSING A DISORDER CALLED FLUOROSIS. IN THE PRESENT STUDY, WE INVESTIGATED THE ALTERATION IN DNA METHYLATION PROFILE WITH CHRONIC EXPOSURE (30 DAYS) TO FLUORIDE (8 MG/L) AND ITS RELEVANCE IN THE DEVELOPMENT OF FLUOROSIS. WHOLE GENOME BISULFITE SEQUENCING (WGBS) WAS CARRIED OUT IN HUMAN OSTEOSARCOMA CELLS (HOS) EXPOSED TO FLUORIDE. WHOLE GENOME BISULFITE SEQUENCING (WGBS) AND FUNCTIONAL ANNOTATION OF DIFFERENTIALLY METHYLATED GENES INDICATE ALTERATIONS IN METHYLATION STATUS OF GENES INVOLVED IN BIOLOGICAL PROCESSES ASSOCIATED WITH BONE DEVELOPMENT PATHWAYS. COMBINED ANALYSIS OF PROMOTER DNA HYPER METHYLATION, STRING: FUNCTIONAL PROTEIN ASSOCIATION NETWORKS AND GENE EXPRESSION ANALYSIS REVEALED EPIGENETIC ALTERATIONS IN BMP1, METAP2, MMP11 AND BACH1 GENES, WHICH PLAYS A ROLE IN THE EXTRACELLULAR MATRIX DISASSEMBLY, COLLAGEN CATABOLIC/ORGANIZATION PROCESS, SKELETAL MORPHOGENESIS/DEVELOPMENT, OSSIFICATION AND OSTEOBLAST DEVELOPMENT. THE PRESENT STUDY SHOWS THAT FLUORIDE CAUSES PROMOTER DNA HYPERMETHYLATION IN BMP1, METAP2, MMP11 AND BACH1 GENES WITH SUBSEQUENT DOWN-REGULATION IN THEIR EXPRESSION LEVEL (RNA LEVEL). THE RESULTS IMPLIES THAT FLUORIDE INDUCED DNA HYPERMETHYLATION OF THESE GENES MAY HAMPER EXTRACELLULAR MATRIX DEPOSITION, CARTILAGE FORMATION, ANGIOGENESIS, VASCULAR SYSTEM DEVELOPMENT AND POROSITY OF BONE, THUS PROMOTE SKELETAL FLUOROSIS. 2019 2 5556 47 ROLE OF FLUORIDE INDUCED HISTONE TRIMETHYLATION IN DEVELOPMENT OF SKELETAL FLUOROSIS. CHRONIC EXPOSURE TO FLUORIDE HAS BEEN ASSOCIATED WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. LIMITED REPORTS ARE AVAILABLE ON FLUORIDE INDUCED HISTONE MODIFICATION. HOWEVER, THE ROLE OF HISTONE MODIFICATION IN THE PATHOGENESIS OF SKELETAL FLUOROSIS IS NOT INVESTIGATED. IN THE PRESENT STUDY, WE HAVE INVESTIGATED THE ROLE OF FLUORIDE INDUCED HISTONE MODIFICATION ON FLUOROSIS DEVELOPMENT USING HUMAN OSTEOSARCOMA (HOS) CELL LINE. THE EXPRESSION OF HISTONE METHYLTRANSFERASES (EHMT1 AND EHZ2) AND LEVEL OF GLOBAL HISTONE TRIMETHYLATION (H3K9 AND H3K27) HAVE BEEN ASSESSED AND OBSERVED TO BE INCREASED SIGNIFICANTLY AFTER FLUORIDE EXPOSURE (8 MG/L). EPITECT CHROMATIN IMMUNOPRECIPITATION (CHIP) QPCR ARRAY (HUMAN TGFBETA/BMP SIGNALING PATHWAY) WAS PERFORMED TO ASSESS THE H3K9 TRIMETHYLATION AT PROMOTER REGIONS OF PATHWAY-SPECIFIC GENES. H3K9 CHIP PCR ARRAY ANALYSIS IDENTIFIED HYPER H3K9 TRIMETHYLATION IN PROMOTER REGIONS OF TGFBR2 AND SMAD3. QPCR AND STRING ANALYSIS WAS CARRIED OUT TO DETERMINE THE REPRESSIVE EPIGENETIC EFFECT OF H3K9 TRIMETHYLATION ON EXPRESSION PATTERN AND FUNCTIONAL ASSOCIATION OF IDENTIFIED GENES. IDENTIFIED GENES (TGFBR2 AND SMAD3) SHOWED DOWN-REGULATION WHICH CONFIRMS THE REPRESSIVE EPIGENETIC EFFECT OF PROMOTER H3K9 HYPER TRIMETHYLATION. EXPRESSION OF TWO OTHER VITAL GENES COL1A1 AND MMP13 INVOLVED IN TGFBR2-SMAD SIGNALING PATHWAY WAS ALSO FOUND TO BE DOWN-REGULATED WITH A DECREASE IN EXPRESSION OF TGFBR2 AND SMAD3. STRING ANALYSIS REVEALED FUNCTIONAL ASSOCIATION AND INVOLVEMENT OF IDENTIFIED GENES TGFBR2, SMAD3, COL1A1 AND MMP13 IN THE COLLAGEN AND CARTILAGE DEVELOPMENT/MORPHOGENESIS, CONNECTIVE TISSUE FORMATION, BIO-MINERAL TISSUE DEVELOPMENT, ENDOCHONDRAL BONE FORMATION, BONE AND SKELETAL MORPHOGENESIS. IN CONCLUSION, PRESENT INVESTIGATION IS A FIRST ATTEMPT TO LINK FLUORIDE INDUCED HYPER H3K9 TRI-METHYLATION MEDIATED REPRESSION OF TGFBR2 AND SMAD3 WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. 2018 3 908 43 CHRONIC EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATION OF FLUORIDE IMPAIRS OSTEOBLAST'S COLLAGEN SYNTHESIS AND MATRIX MINERALIZATION: INVOLVEMENT OF EPIGENETIC REGULATION IN SKELETAL FLUOROSIS. GLOBALLY, 200 MILLION PEOPLE ARE SUFFERING FROM TOXIC MANIFESTATIONS OF FLUORIDE(F), DENTAL AND SKELETAL FLUOROSIS; UNFORTUNATELY, THERE IS NO TREATMENT. TO UNRAVEL THE PATHOGENESIS OF SKELETAL FLUOROSIS, WE ESTABLISHED FLUOROSIS MICE BY TREATING ENVIRONMENTALLY RELEVANT CONCENTRATION OF F (15 PPM NAF) THROUGH DRINKING WATER FOR 4 MONTHS. AS IN SKELETAL FLUOROSIS, LOCOMOTOR DISABILITY, CRIPPLING DEFORMITIES OCCUR AND THUS, OUR HYPOTHESIS WAS F MIGHT ADVERSELY AFFECTS COLLAGEN WHICH GIVES THE BONE TENSILE STRENGTH. THIS WORK INEVITABLY HAD TO BE CARRIED OUT ON OSTEOBLAST CELLS, RESPONSIBLE FOR SYNTHESIS, DEPOSITION, AND MINERALIZATION OF BONE MATRIX. ISOLATED OSTEOBLAST CELLS WERE CONFIRMED BY ALP ACTIVITY AND MINERALIZED NODULES FORMATION. EXPRESSION OF COLLAGEN COL1A1, COL1A2, COL1A1 WAS SIGNIFICANTLY REDUCED IN TREATED MICE. FURTHER, A STUDY REVEALED THE INVOLVEMENT OF EPIGENETIC REGULATION BY PROMOTER HYPERMETHYLATION OF COL1A1; EXPRESSIONAL ALTERATIONS OF TRANSCRIPTION FACTORS, CALCIUM CHANNELS AND OTHER GENES E.G., CBFA-1, TGF-BETA1, BMP1, SP1, SP7, NF-(K)B P65, BMP-2, BGLAP, GPRC6A AND CAV(1.2) ARE ASSOCIATED WITH IMPAIRMENT OF COLLAGEN SYNTHESIS, DEPOSITION AND DECREASED MINERALIZATION THUS, ENFEEBLING BONE HEALTH. THIS STUDY INDICATES THE POSSIBLE ASSOCIATION OF EPIGENETIC REGULATION IN SKELETAL FLUOROSIS. HOWEVER, NO ASSOCIATION WAS FOUND BETWEEN POLYMORPHISMS IN THE COL1A1 (RSAI, HINDIII) AND COL1A2 (RSAI, HINDIII) GENES WITH FLUOROSIS IN MICE. 2023 4 122 27 A SYSTEMATIC REVIEW ON FLUORIDE-INDUCED EPIGENETIC TOXICITY IN MAMMALS. FLUORIDE, ONE OF THE GLOBAL GROUNDWATER CONTAMINANTS, IS UBIQUITOUS IN OUR DAY-TO-DAY LIFE FROM VARIOUS NATURAL AND ANTHROPOGENIC SOURCES. NUMEROUS IN VITRO, IN VIVO, AND EPIDEMIOLOGICAL STUDIES ARE CONDUCTED TO UNDERSTAND THE EFFECT OF FLUORIDE ON BIOLOGICAL SYSTEMS. A LOW CONCENTRATION OF FLUORIDE IS REPORTED TO INCREASE ORAL HEALTH, WHEREAS CHRONIC EXPOSURE TO HIGHER CONCENTRATIONS CAUSES FLUORIDE TOXICITY (FLUOROSIS). IT INCLUDES DENTAL FLUOROSIS, SKELETAL FLUOROSIS, AND FLUORIDE TOXICITY IN SOFT TISSUES. THE MECHANISM OF FLUORIDE TOXICITY HAS BEEN REVIEWED EXTENSIVELY. HOWEVER, EPIGENETIC REGULATION IN FLUORIDE TOXICITY HAS NOT BEEN REVIEWED. THIS SYSTEMATIC REVIEW SUMMARIZES THE CURRENT KNOWLEDGE REGARDING FLUORIDE-INDUCED EPIGENETIC TOXICITY IN THE IN VITRO, IN VIVO, AND EPIDEMIOLOGICAL STUDIES IN MAMMALIAN SYSTEMS. WE EXAMINED FOUR DATABASES FOR THE ASSOCIATION BETWEEN EPIGENETICS AND FLUORIDE EXPOSURE. OUT OF 932 ARTICLES (AS OF 31 MARCH 2022), 39 MET OUR INCLUSION CRITERIA. MOST OF THE STUDIES FOCUSED ON DIFFERENT GENES, AND OVERALL, PRELIMINARY EVIDENCE FOR EPIGENETIC REGULATION OF FLUORIDE TOXICITY WAS IDENTIFIED. WE FURTHER HIGHLIGHT THE NEED FOR EPIGENOME STUDIES RATHER THAN CANDIDATE GENES AND PROVIDE RECOMMENDATIONS FOR FUTURE RESEARCH. OUR RESULTS INDICATE A CORRELATION BETWEEN FLUORIDE EXPOSURE AND EPIGENETIC PROCESSES. FURTHER STUDIES ARE WARRANTED TO ELUCIDATE AND CONFIRM THE MECHANISM OF EPIGENETIC ALTERATIONS MEDIATED FLUORIDE TOXICITY. 2022 5 907 35 CHRONIC EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATION OF FLUORIDE ALTERS OGG1 AND RAD51 EXPRESSIONS IN MICE: INVOLVEMENT OF EPIGENETIC REGULATION. CHRONIC EXPOSURE TO FLUORIDE (F) BEYOND THE PERMISSIBLE LIMIT (1.5 PPM) IS KNOWN TO CAUSE DETRIMENTAL HEALTH EFFECTS BY INDUCTION OF OXIDATIVE STRESS-MEDIATED DNA DAMAGE OVERPOWERING THE DNA REPAIR MACHINERY. IN THE PRESENT STUDY, WE ASSESSED F INDUCED OXIDATIVE STRESS THROUGH MONITORING BIOCHEMICAL PARAMETERS AND LOOKED INTO THE EFFECT OF CHRONIC F EXPOSURE ON TWO CRUCIAL DNA REPAIR GENES OGG1 AND RAD51 HAVING IMPORTANT ROLE AGAINST ROS INDUCED DNA DAMAGES. TO ADDRESS THIS ISSUE, WE EXPOSED SWISS ALBINO MICE TO AN ENVIRONMENTALLY RELEVANT CONCENTRATION OF FLUORIDE (15 PPM NAF) FOR 8 MONTHS. RESULTS REVEALED HISTOARCHITECTURAL DAMAGES IN LIVER, BRAIN, KIDNEY AND SPLEEN. DEPLETION OF GSH, INCREASE IN LIPID PEROXIDATION AND CATALASE ACTIVITY IN LIVER AND BRAIN CONFIRMED THE GENERATION OF OXIDATIVE STRESS. QRT-PCR RESULT SHOWED THAT EXPRESSIONS OF OGG1 AND RAD51 WERE ALTERED AFTER F EXPOSURE IN THE AFFECTED ORGANS. PROMOTER HYPERMETHYLATION WAS ASSOCIATED WITH THE DOWNREGULATION OF RAD51. F-INDUCED DNA DAMAGE AND THE COMPROMISED DNA REPAIR MACHINERY TRIGGERED INTRINSIC PATHWAY OF APOPTOSIS IN LIVER AND BRAIN. THE PRESENT STUDY INDICATES THE POSSIBLE ASSOCIATION OF EPIGENETIC REGULATION WITH F INDUCED NEUROTOXICITY. 2020 6 1545 31 DNA METHYLATION IN LIVER TUMORIGENESIS IN FISH FROM THE ENVIRONMENT. THE LINK BETWEEN ENVIRONMENT, ALTERATION IN DNA METHYLATION AND CANCER HAS BEEN WELL ESTABLISHED IN HUMANS; YET, IT IS UNDER-STUDIED IN UNSEQUENCED NON-MODEL ORGANISMS. THE OCCURRENCE OF LIVER TUMORS IN THE FLATFISH DAB COLLECTED AT CERTAIN UK SAMPLING SITES EXCEEDS 20%, YET THE CAUSATIVE AGENTS AND THE MOLECULAR MECHANISMS OF TUMOR FORMATION ARE NOT KNOWN, ESPECIALLY REGARDING THE BALANCE BETWEEN EPIGENETIC AND GENETIC FACTORS. METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) COMBINED WITH DE NOVO HIGH-THROUGHPUT DNA SEQUENCING WERE USED TO INVESTIGATE DNA METHYLATION CHANGES IN DAB HEPATOCELLULAR ADENOMA TUMORS FOR THE FIRST TIME IN AN UNSEQUENCED SPECIES. NOVEL CUSTOM-MADE DAB GENE EXPRESSION ARRAYS WERE DESIGNED AND USED TO DETERMINE THE RELATIONSHIP BETWEEN DNA METHYLATION AND GENE EXPRESSION. IN ADDITION, THE CONFIRMATORY TECHNIQUES OF BISULFITE SEQUENCING PCR (BSP) AND RT-PCR WERE APPLIED. GENES INVOLVED IN PATHWAYS RELATED TO CANCER, INCLUDING APOPTOSIS, WNT/BETA-CATENIN SIGNALING AND GENOMIC AND NON-GENOMIC ESTROGEN RESPONSES, WERE ALTERED BOTH IN METHYLATION AND TRANSCRIPTION. GLOBAL METHYLATION WAS STATISTICALLY SIGNIFICANTLY 1.8-FOLD REDUCED IN HEPATOCELLULAR ADENOMA AND NON-CANCEROUS SURROUNDING TISSUES COMPARED WITH LIVER FROM NON-CANCER BEARING DAB. BASED ON THE IDENTIFIED CHANGES AND CHEMICAL EXPOSURE DATA, OUR STUDY SUPPORTS THE EPIGENETIC MODEL OF CANCER. WE HYPOTHESIZE THAT CHRONIC EXPOSURE TO A MIXTURE OF ENVIRONMENTAL CONTAMINANTS CONTRIBUTES TO A GLOBAL HYPOMETHYLATION FOLLOWED BY FURTHER EPIGENETIC AND GENOMIC CHANGES. THE FINDINGS SUGGEST A LINK BETWEEN ENVIRONMENT, EPIGENETICS AND CANCER IN FISH TUMORS IN THE WILD AND SHOW THE UTILITY OF THIS METHODOLOGY FOR STUDIES IN NON-MODEL ORGANISMS. 2011 7 1965 36 EPIGENETIC ALTERATION OF MITOCHONDRIAL BIOGENESIS REGULATORY GENES IN ARSENIC EXPOSED INDIVIDUALS (WITH AND WITHOUT SKIN LESIONS) AND IN SKIN CANCER TISSUES: A CASE CONTROL STUDY. CHRONIC ARSENIC TOXICITY HAS BECOME A GLOBAL CONCERN DUE TO ITS ADVERSE PATHOPHYSIOLOGICAL OUTCOME AND CARCINOGENIC POTENTIAL. IT IS ALREADY ESTABLISHED THAT ARSENIC INDUCED REACTIVE OXYGEN SPECIES ALTERS MITOCHONDRIAL FUNCTIONALITY. MAJOR REGULATORY GENES FOR MITOCHONDRIAL BIOGENESIS, I.E., PGC1ALPHA, TFAM, NRF1AND NRF2 ARE LOCATED IN THE NUCLEUS. AS A RESULT, MITOCHONDRIA-NUCLEUS CROSSTALK IS CRUCIAL FOR PROPER MITOCHONDRIAL FUNCTION. THIS PREVIOUS HYPOTHESIS LED US TO INVESTIGATEINVOLVEMENT OF EPIGENETIC ALTERATION BEHINDENHANCED MITOCHONDRIAL BIOGENESIS IN CHRONIC ARSENIC EXPOSURE. AN EXTENSIVE CASE-CONTROL STUDY WAS CONDUCTED WITH 390 STUDY PARTICIPANTS (UNEXPOSED, EXPOSED WITHOUT SKIN LESION, EXPOSED WITH SKIN LESION AND EXPOSED SKIN TUMOUR) FROM HIGHLY ARSENIC EXPOSED AREAS OFWEST BENGAL, INDIA. METHYLATION SPECIFIC PCRREVEALED SIGNIFICANT PROMOTER HYPOMETHYLATION OFTWO KEY BIOGENESIS REGULATORY GENES, PGC1ALPHAANDTFAM IN ARSENIC EXPOSED INDIVIDUALS AND ALSO IN SKIN TUMOUR TISSUES. LINEAR REGRESSION ANALYSIS INDICATED SIGNIFICANT NEGATIVE CORRELATION BETWEEN URINARY ARSENIC CONCENTRATION AND PROMOTER METHYLATION STATUS. INCREASED EXPRESSION OF BIOGENESIS REGULATORY GENES WASOBTAINED BY QUANTITATIVE REAL-TIME PCR ANALYSIS. MOREOVER, ALTERED MITOCHONDRIAL FUSION-FISSION REGULATORY GENE EXPRESSION WAS ALSO OBSERVED IN SKIN TUMOUR TISSUES. MIR663, HAVING TUMOUR SUPPRESSOR GENE LIKE FUNCTION WAS KNOWN TO BE EPIGENETICALLY REGULATED THROUGH MITOCHONDRIAL RETROGRADE SIGNAL. PROMOTER HYPERMETHYLATION WITH SIGNIFICANTLY DECREASED EXPRESSION OF MIR663 WAS FOUND IN SKIN CANCER TISSUES COMPARED TO NON-CANCEROUS CONTROL TISSUE. IN CONCLUSION, RESULTS INDICATED CRUCIAL ROLE OF EPIGENETIC ALTERATION IN ARSENIC INDUCED MITOCHONDRIAL BIOGENESIS AND ARSENICAL SKIN CARCINOGENESIS FOR THE FIRST TIME. HOWEVER, FURTHER MECHANISTIC STUDIES ARE NECESSARY FOR DETAILED UNDERSTANDING OF MITOCHONDRIA-NUCLEUS CROSSTALK IN ARSENIC PERTURBATION. 2020 8 1567 31 DNA METHYLATION OF THE KLF14 GENE REGION IN WHOLE BLOOD CELLS PROVIDES PREDICTION FOR THE CHRONIC INFLAMMATION IN THE ADIPOSE TISSUE. KRUPPEL-LIKE FACTOR 14 (KLF14) GENE, WHICH APPEARS TO BE A MASTER REGULATOR OF GENE EXPRESSION IN THE ADIPOSE TISSUE AND HAVE PREVIOUSLY BEEN ASSOCIATED WITH BMI AND TYPE 2 DIABETES (T2D) BY LARGE GENOME-WIDE ASSOCIATION STUDIES. IN ORDER TO FIND PREDICTIVE BIOMARKERS FOR THE DEVELOPMENT OF T2D, IT IS NECESSARY TO TAKE EPIGENOMIC CHANGES AFFECTED BY ENVIRONMENTAL FACTORS INTO ACCOUNT. THIS STUDY FOCUSES ON AGEING AND OBESITY, WHICH ARE T2D RISK FACTORS, AND EXAMINES EPIGENETIC CHANGES AND INFLAMMATORY CHANGES. WE INVESTIGATED DNA METHYLATION CHANGES IN THE KLF14 PROMOTER REGION IN DIFFERENT ORGANS OF MICE FOR COMPARING AGING AND WEIGHT. WE FOUND THAT METHYLATION LEVELS OF THESE SITES WERE INCREASED WITH AGING AND WEIGHT IN THE SPLEEN, THE ADIPOSE TISSUE, THE KIDNEY, THE LUNG, THE COLON AND THE WHOLE BLOOD CELLS. IN ADDITION, IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD, THESE EPIGENETIC CHANGES WERE ALSO SIGNIFICANTLY ASSOCIATED WITH INFLAMMATORY LEVELS. MOREOVER, NOT ONLY KLF14, BUT ALSO EXPRESSION LEVELS OF SOME DOWNSTREAM GENES WERE DECREASED WITH METHYLATION IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD CELLS. TAKEN TOGETHER, OUR RESULTS SUGGEST THAT METHYLATION CHANGES OF KLF14 IN THOSE TISSUES MAY BE ASSOCIATED WITH CHANGES IN GENE EXPRESSION AND INFLAMMATION ON THE ADIPOSE TISSUE OF OBESITY AND T2D. IN ADDITION, THE METHYLATION CHANGES IN THE WHOLE BLOOD CELLS MAY SERVE AS A PREDICTIVE EPIGENETIC BIOMARKER FOR THE DEVELOPMENT OF T2D. 2018 9 3473 30 IDENTIFICATION OF A NOVEL, METHYLATION-DEPENDENT, RUNX2 REGULATORY REGION ASSOCIATED WITH OSTEOARTHRITIS RISK. OSTEOARTHRITIS (OA) IS A COMMON, MULTIFACTORIAL AND POLYGENIC SKELETAL DISEASE THAT, IN ITS SEVEREST FORM, REQUIRES JOINT REPLACEMENT SURGERY TO RESTORE MOBILITY AND TO RELIEVE CHRONIC PAIN. USING TISSUES FROM THE ARTICULATING JOINTS OF 260 PATIENTS WITH OA AND A RANGE OF IN VITRO EXPERIMENTS, INCLUDING CRISPR-CAS9, WE HAVE CHARACTERIZED AN INTERGENIC REGULATORY ELEMENT. HERE, GENOTYPE AT AN OA RISK LOCUS CORRELATES WITH DIFFERENTIAL DNA METHYLATION, WITH ALTERED GENE EXPRESSION OF BOTH A TRANSCRIPTIONAL REGULATOR (RUNX2), AND A CHROMATIN REMODELLING PROTEIN (SUPT3H). RUNX2 IS A STRONG CANDIDATE FOR OA SUSCEPTIBILITY, WITH ITS ENCODED PROTEIN BEING ESSENTIAL FOR SKELETOGENESIS AND HEALTHY JOINT FUNCTION. THE OA RISK LOCUS INCLUDES SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) LOCATED WITHIN AND FLANKING THE DIFFERENTIALLY METHYLATED REGION (DMR). THE OA ASSOCIATION SNP, RS10948172, DEMONSTRATES PARTICULARLY STRONG CORRELATION WITH METHYLATION, AND TWO INTERGENIC SNPS FALLING WITHIN THE DMR (RS62435998 AND RS62435999) DEMONSTRATE GENETIC AND EPIGENETIC EFFECTS ON THE REGULATORY ACTIVITY OF THIS REGION. WE THEREFORE POSIT THAT THE OA SIGNAL MEDIATES ITS EFFECT BY MODULATING THE METHYLATION OF THE REGULATORY ELEMENT, WHICH THEN IMPACTS ON GENE EXPRESSION, WITH RUNX2 BEING THE PRINCIPAL TARGET. OUR STUDY HIGHLIGHTS THE INTERPLAY BETWEEN DNA METHYLATION, OA GENETIC RISK AND THE DOWNSTREAM REGULATION OF GENES CRITICAL TO NORMAL JOINT FUNCTION. 2018 10 1584 23 DNA METHYLATION PROFILES OF SELECTED PRO-INFLAMMATORY CYTOKINES IN ALZHEIMER DISEASE. BY MEANS OF FUNCTIONAL GENOMICS ANALYSIS, WE RECENTLY DESCRIBED THE MRNA EXPRESSION PROFILES OF VARIOUS GENES INVOLVED IN THE NEUROINFLAMMATORY RESPONSE IN THE BRAINS OF SUBJECTS WITH LATE-ONSET ALZHEIMER DISEASE (LOAD). SOME OF THESE GENES, NAMELY INTERLEUKIN (IL)-1BETA AND IL-6, SHOWED DISTINCT EXPRESSION PROFILES WITH PEAK EXPRESSION DURING THE FIRST STAGES OF THE DISEASE AND CONTROL-LIKE LEVELS AT LATER STAGES. IL-1BETA AND IL-6 GENES ARE MODULATED BY DNA METHYLATION IN DIFFERENT CHRONIC AND DEGENERATIVE DISEASES; IT IS ALSO WELL KNOWN THAT LOAD MAY HAVE AN EPIGENETIC BASIS. INDEED, WE AND OTHERS HAVE PREVIOUSLY REPORTED GENE-SPECIFIC DNA METHYLATION ALTERATIONS IN LOAD AND IN RELATED ANIMAL MODELS. BASED ON THESE DATA, WE STUDIED THE DNA METHYLATION PROFILES, AT SINGLE CYTOSINE RESOLUTION, OF IL-1BETA AND IL-6 5'-FLANKING REGION BY BISULPHITE MODIFICATION IN THE CORTEX OF HEALTHY CONTROLS AND LOAD PATIENTS AT 2 DIFFERENT DISEASE STAGES: BRAAK I-II/A AND BRAAK V-VI/C. OUR ANALYSIS PROVIDES EVIDENCE THAT NEUROINFLAMMATION IN LOAD IS ASSOCIATED WITH (AND POSSIBLY MEDIATED BY) EPIGENETIC MODIFICATIONS. 2017 11 1117 25 COMPARATIVE AND EXPERIMENTAL STUDIES ON THE GENES ALTERED BY CHRONIC HYPOXIA IN HUMAN BRAIN MICROENDOTHELIAL CELLS. BACKGROUND : HYPOXIA INDUCIBLE FACTOR 1 ALPHA (HIF1A) IS A MASTER REGULATOR OF ACUTE HYPOXIA; HOWEVER, WITH CHRONIC HYPOXIA, HIF1A LEVELS RETURN TO THE NORMOXIC LEVELS. IMPORTANTLY, THE GENES THAT ARE INVOLVED IN THE CELL SURVIVAL AND VIABILITY UNDER CHRONIC HYPOXIA ARE NOT KNOWN. THEREFORE, WE TESTED THE HYPOTHESIS THAT CHRONIC HYPOXIA LEADS TO THE UPREGULATION OF A CORE GROUP OF GENES WITH ASSOCIATED CHANGES IN THE PROMOTER DNA METHYLATION THAT MEDIATES THE CELL SURVIVAL UNDER HYPOXIA. RESULTS : WE EXAMINED THE EFFECT OF CHRONIC HYPOXIA (3 DAYS; 0.5% OXYGEN) ON HUMAN BRAIN MICRO ENDOTHELIAL CELLS (HBMEC) VIABILITY AND APOPTOSIS. HYPOXIA CAUSED A SIGNIFICANT REDUCTION IN CELL VIABILITY AND AN INCREASE IN APOPTOSIS. NEXT, WE EXAMINED CHRONIC HYPOXIA ASSOCIATED CHANGES IN TRANSCRIPTOME AND GENOME-WIDE PROMOTER METHYLATION. THE DATA OBTAINED WAS COMPARED WITH 16 OTHER MICROARRAY STUDIES ON CHRONIC HYPOXIA. NINE GENES WERE ALTERED IN RESPONSE TO CHRONIC HYPOXIA IN ALL 17 STUDIES. INTERESTINGLY, HIF1A WAS NOT ALTERED WITH CHRONIC HYPOXIA IN ANY OF THE STUDIES. FURTHERMORE, WE COMPARED OUR DATA TO THREE OTHER STUDIES THAT IDENTIFIED HIF-RESPONSIVE GENES BY VARIOUS APPROACHES. ONLY TWO GENES WERE FOUND TO BE HIF DEPENDENT. WE SILENCED EACH OF THESE 9 GENES USING CRISPR/CAS9 SYSTEM. DOWNREGULATION OF EGLN3 SIGNIFICANTLY INCREASED THE CELL DEATH UNDER CHRONIC HYPOXIA, WHEREAS DOWNREGULATION OF ERO1L, ENO2, ADRENOMEDULLIN, AND SPAG4 REDUCED THE CELL DEATH UNDER HYPOXIA. CONCLUSIONS : WE PROVIDE A CORE GROUP OF GENES THAT REGULATES CELLULAR ACCLIMATIZATION UNDER CHRONIC HYPOXIC STRESS, AND MOST OF THEM ARE HIF INDEPENDENT. 2017 12 3468 41 HYPOXIA-INDUCED DNA HYPERMETHYLATION IN HUMAN PULMONARY FIBROBLASTS IS ASSOCIATED WITH THY-1 PROMOTER METHYLATION AND THE DEVELOPMENT OF A PRO-FIBROTIC PHENOTYPE. BACKGROUND: PULMONARY FIBROSIS IS A DEBILITATING AND LETHAL DISEASE WITH NO EFFECTIVE TREATMENT OPTIONS. UNDERSTANDING THE PATHOLOGICAL PROCESSES AT PLAY WILL DIRECT THE APPLICATION OF NOVEL THERAPEUTIC AVENUES. HYPOXIA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF PULMONARY FIBROSIS YET THE PRECISE MECHANISM BY WHICH IT CONTRIBUTES TO DISEASE PROGRESSION REMAINS TO BE FULLY ELUCIDATED. IT HAS BEEN SHOWN THAT CHRONIC HYPOXIA CAN ALTER DNA METHYLATION PATTERNS IN TUMOUR-DERIVED CELL LINES. THIS EPIGENETIC ALTERATION CAN INDUCE CHANGES IN CELLULAR PHENOTYPE WITH PROMOTER METHYLATION BEING ASSOCIATED WITH GENE SILENCING. OF PARTICULAR RELEVANCE TO IDIOPATHIC PULMONARY FIBROSIS (IPF) IS THE OBSERVATION THAT THY-1 PROMOTER METHYLATION IS ASSOCIATED WITH A MYOFIBROBLAST PHENOTYPE WHERE LOSS OF THY-1 OCCURS ALONGSIDE INCREASED ALPHA SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION. THE INITIAL AIM OF THIS STUDY WAS TO DETERMINE WHETHER HYPOXIA REGULATES DNA METHYLATION IN NORMAL HUMAN LUNG FIBROBLASTS (CCD19LU). AS IT HAS BEEN REPORTED THAT HYPOXIA SUPPRESSES THY-1 EXPRESSION DURING LUNG DEVELOPMENT WE ALSO STUDIED THE EFFECT OF HYPOXIA ON THY-1 PROMOTER METHYLATION AND GENE EXPRESSION. METHODS: CCD19LU WERE GROWN FOR UP TO 8 DAYS IN HYPOXIA AND ASSESSED FOR GLOBAL CHANGES IN DNA METHYLATION USING FLOW CYTOMETRY. REAL-TIME PCR WAS USED TO QUANTIFY EXPRESSION OF THY-1, ALPHA-SMA, COLLAGEN I AND III. GENOMIC DNA WAS BISULPHITE TREATED AND METHYLATION SPECIFIC PCR (MSPCR) WAS USED TO EXAMINE THE METHYLATION STATUS OF THE THY-1 PROMOTER. RESULTS: SIGNIFICANT GLOBAL HYPERMETHYLATION WAS DETECTED IN HYPOXIC FIBROBLASTS RELATIVE TO NORMOXIC CONTROLS AND WAS ACCOMPANIED BY INCREASED EXPRESSION OF MYOFIBROBLAST MARKERS. THY-1 MRNA EXPRESSION WAS SUPPRESSED IN HYPOXIC CELLS, WHICH WAS RESTORED WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE. MSPCR REVEALED THAT THY-1 BECAME METHYLATED FOLLOWING FIBROBLAST EXPOSURE TO 1% O2. CONCLUSION: THESE DATA SUGGEST THAT GLOBAL AND GENE-SPECIFIC CHANGES IN DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN FIBROBLAST FUNCTION IN HYPOXIA. 2012 13 1615 28 DNA METHYLTRANSFERASE 3B PLAYS A PROTECTIVE ROLE AGAINST HEPATOCARCINOGENESIS CAUSED BY CHRONIC INFLAMMATION VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. MOST HEPATOCELLULAR CARCINOMAS (HCCS) DEVELOP ON THE BASIS OF CHRONIC HEPATITIS, BUT THE MECHANISM OF EPIGENETIC REGULATION IN INFLAMMATORY HEPATOCARCINOGENESIS HAS YET TO BE ELUCIDATED. AMONG DE NOVO DNA METHYLTRANSFERASES (DNMTS), DNMT3B HAS LATELY BEEN REPORTED TO ACT SPECIFICALLY ON ACTIVELY TRANSCRIBED GENES, SUGGESTING THE POSSIBILITY THAT IT PLAYS A ROLE IN THE PATHOGENESIS OF CANCER. WE CONFIRMED THAT DNMT3B ISOFORMS LACKING ITS CATALYTIC DOMAIN WERE HIGHLY EXPRESSED IN HCCS COMPARED WITH NON-TUMOROUS LIVER TISSUE. TO ELUCIDATE THE ROLE OF DNMT3B IN HEPATOCARCINOGENESIS, WE GENERATED A GENETICALLY ENGINEERED MOUSE MODEL WITH HEPATOCYTE-SPECIFIC DNMT3B DELETION. THE LIVER OF THE DNMT3B-DEFICIENT MICE EXHIBITED AN EXACERBATION OF THIOACETAMIDE-INDUCED HEPATITIS, PROGRESSION OF LIVER FIBROSIS AND A HIGHER INCIDENCE OF HCC COMPARED WITH THE LIVER OF THE CONTROL MICE. WHOLE-GENOME BISULFITE SEQUENCING VERIFIED A LOWER CG METHYLATION LEVEL IN THE DNMT3B-DEFICIENT LIVER, DEMONSTRATING DIFFERENTIALLY METHYLATED REGIONS THROUGHOUT THE GENOME. TRANSCRIPTOME ANALYSIS REVEALED DECREASED EXPRESSION OF GENES RELATED TO OXIDATIVE PHOSPHORYLATION IN THE DNMT3B-DEFICIENT LIVER. MOREOVER, PRIMARY HEPATOCYTES ISOLATED FROM THE DNMT3B-DEFICIENT MICE SHOWED REDUCED MITOCHONDRIAL RESPIRATORY CAPACITY, LEADING TO THE ENHANCEMENT OF OXIDATIVE STRESS IN THE LIVER TISSUE. OUR FINDINGS SUGGEST THE PROTECTIVE ROLE OF DNMT3B AGAINST CHRONIC INFLAMMATION AND HCC DEVELOPMENT VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. 2020 14 6794 26 [EFFECT OF BENZO(A)PYRENE ON THE EXPRESSION OF AHR-REGULATED MICRORNA IN FEMALE AND MALE RAT LUNGS]. SMOKING IS THE MAIN RISK FACTOR FOR LUNG CANCER, MAINLY DUE TO PRESENCE OF NITROSAMINES AND POLYCYCLIC AROMATIC HYDROCARBONS, INCLUDING BENZO[A]PYRENE (BP) IN TOBACCO SMOKE COMPOSITION. THE GENOTOXIC EFFECT OF BP IS BASED ON THE HIGH DNA-BINDING ABILITY OF ITS METABOLITES, WHILE THE EPIGENETIC EFFECTS ARE MEDIATED BY A CHANGE IN THE EXPRESSION OF CANCER RELATED GENES OR REGULATORY RNAS. IT HAS BEEN SHOWN THAT WOMEN HAVE A HIGHER RISK TO DEVELOP LUNG CANCER UPON SMOKING RATHER THAN MEN. WE HYPOTHESIZED THAT CROSSTALK BETWEEN SIGNALING PATHWAYS ACTIVATED BY BP AND ESTROGENS COULD UNDERLIE THE SEX-DEPENDENT DIFFERENCES IN MIRNAS EXPRESSION. TO TEST THIS HYPOTHESIS, MALE AND FEMALE RATS WERE SUBJECTED TO SHORT-TERM OR LONG-TERM BP EXPOSURE. USING IN SILICO ANALYSIS, MIRNAS CONTAINING THE ER- AND AHR-BINDING SITES IN THE PROMOTERS OF THE GENES (OR HOST GENES) WERE SELECTED. DURING CHRONIC EXPOSURE OF BP THE EXPRESSION OF MIR-22-3P, -29A-3P, -126A-3P, -193B-5P IN THE LUNGS OF MALE RATS WERE SIGNIFICANTLY INCREASED, WHILE THE LEVEL OF MIRNA-483-3P WERE DECREASED. EXPRESSION OF MIRNA-483-3P WAS UP-REGULATED DURING CHRONIC BP EXPOSURE IN THE LUNGS OF FEMALE RATS AND THE LEVELS OF OTHER STUDIED MIRNAS WERE UNCHANGED. IN TURN, CHANGES IN THE EXPRESSION OF MIRNAS WERE FOLLOWED BY CHANGES IN THE EXPRESSION OF THEIR TARGET GENES, INCLUDING PTEN, EMP2, IGF1, ITGA6, SLC34A2, AND THE OBSERVED CHANGES IN FEMALE AND MALE RAT LUNGS WERE VARIED. THUS, OUR RESULTS SUGGEST THAT SEX-DEPENDENT EPIGENETIC EFFECTS OF BP MAY BE BASED ON DIFFERENT EXPRESSION OF AHR- AND ER- REGULATED MIRNAS. 2020 15 4528 21 MULTIGENERATIONAL EFFECTS OF CADMIUM ON THE LIFESPAN AND FERTILITY OF DROSOPHILA MELANOGASTER. ALTHOUGH THE DAMAGE AND TOLERANCE MECHANISMS OF CD STRESS ARE KNOWN, THE DATA ON GENETIC RISK ARE LIMITED. THE AIM OF THIS STUDY WAS TO ASSESS THE CHRONIC TOXICITY OF CD, GENETIC RESPONSES, AND MULTIGENERATIONAL EFFECTS IN FIVE GENERATIONS OF DROSOPHILA MELANOGASTER. FOR EACH GENERATION, LIFESPAN AND FERTILITY WERE STATISTICALLY ANALYSED AND THE EXPRESSION OF APOPTOSIS- (P53 AND CASPASE-3) AND EPIGENESIS-RELATED (DDNMT2 AND DMBD2/3) GENES WAS EXAMINED. LIFESPAN AND FERTILITY SIGNIFICANTLY DECLINED UNDER CD STRESS AND THESE EFFECTS WERE MAINTAINED FOR TWO GENERATIONS AND ONE GENERATION, RESPECTIVELY, WHEN CD STRESS WAS REMOVED. THE EXPRESSION OF P53 AND CASPASE-3 WAS SIGNIFICANTLY UP-REGULATED AFTER EXPOSURE, SUGGESTING THAT APOPTOSIS CONTRIBUTES TO THE RESISTANCE MECHANISM. THEIR ALTERED EXPRESSION WAS RETAINED FOR TWO GENERATIONS. FURTHERMORE, HIGH EXPRESSION OF DDNMT2 AND DMBD2/3 ACCOMPANIED CD EXPOSURE, WHICH WAS PASSED ON TO THREE GENERATIONS, SUGGESTING THAT GENETIC MODIFICATIONS IN APOPTOSIS-RELATED GENES ARE CARRIED TO THE OFFSPRING THROUGH EPIGENETIC REGULATION. 2020 16 5972 24 TET REPRESSION AND INCREASED DNMT ACTIVITY SYNERGISTICALLY INDUCE ABERRANT DNA METHYLATION. CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN VARIOUS HUMAN DISORDERS, SUCH AS CANCER, NEURODEGENERATIVE DISORDERS, AND METABOLIC DISORDERS. INDUCTION OF EPIGENETIC ALTERATIONS, ESPECIALLY ABERRANT DNA METHYLATION, IS ONE OF THE MAJOR MECHANISMS, BUT HOW IT IS INDUCED IS STILL UNCLEAR. HERE, WE FOUND THAT EXPRESSION OF TET GENES, METHYLATION ERASERS, WAS DOWNREGULATED IN INFLAMED MOUSE AND HUMAN TISSUES, AND THAT THIS WAS CAUSED BY UPREGULATION OF TET-TARGETING MIRNAS SUCH AS MIR20A, MIR26B, AND MIR29C, LIKELY DUE TO ACTIVATION OF NF-KAPPAB SIGNALING DOWNSTREAM OF IL-1BETA AND TNF-ALPHA. HOWEVER, TET KNOCKDOWN INDUCED ONLY MILD ABERRANT METHYLATION. NITRIC OXIDE (NO), PRODUCED BY NOS2, ENHANCED ENZYMATIC ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), METHYLATION WRITERS, AND NO EXPOSURE INDUCED MINIMAL ABERRANT METHYLATION. IN CONTRAST, A COMBINATION OF TET KNOCKDOWN AND NO EXPOSURE SYNERGISTICALLY INDUCED ABERRANT METHYLATION, INVOLVING GENOMIC REGIONS NOT METHYLATED BY EITHER ALONE. THE RESULTS SHOWED THAT A VICIOUS COMBINATION OF TET REPRESSION, DUE TO NF-KAPPAB ACTIVATION, AND DNMT ACTIVATION, DUE TO NO PRODUCTION, IS RESPONSIBLE FOR ABERRANT METHYLATION INDUCTION IN HUMAN TISSUES. 2020 17 1011 28 CIGARETTE SMOKE CONDENSATE INDUCES DIFFERENTIAL EXPRESSION AND PROMOTER METHYLATION PROFILES OF CRITICAL GENES INVOLVED IN LUNG CANCER IN NL-20 LUNG CELLS IN VITRO: SHORT-TERM AND CHRONIC EXPOSURE. ESTABLISHING EARLY DIAGNOSTIC MARKERS OF HARM IS CRITICAL FOR EFFECTIVE PREVENTION PROGRAMS AND REGULATION OF TOBACCO PRODUCTS. THIS STUDY EXAMINED EFFECTS OF CIGARETTE SMOKE CONDENSATE (CSC) ON EXPRESSION AND PROMOTER METHYLATION PROFILE OF CRITICAL GENES (DAPK, ECAD, MGMT, AND RASSF1A) INVOLVED IN LUNG CANCER DEVELOPMENT IN DIFFERENT HUMAN LUNG CELL LINES. NL-20 CELLS WERE TREATED WITH 0.1-100 MUG/ML OF CSC FOR 24 TO 72 HRS FOR SHORT-TERM EXPOSURES. DAPK EXPRESSION OR METHYLATION STATUS WAS NOT SIGNIFICANTLY AFFECTED. HOWEVER, CSC TREATMENT RESULTED IN CHANGES IN EXPRESSION AND PROMOTER METHYLATION PROFILE OF ECAD, MGMT, AND RASSF1A. FOR CHRONIC STUDIES, CELLS WERE EXPOSED TO 1 OR 10 MUG/ML CSC UP TO 28 DAYS. CELLS SHOWED MORPHOLOGICAL CHANGES ASSOCIATED WITH TRANSFORMATION AND CHANGES IN INVASION CAPACITIES AND GLOBAL METHYLATION STATUS. THIS STUDY PROVIDES CRITICAL DATA SUGGESTING THAT EPIGENETIC CHANGES COULD SERVE AS AN EARLY BIOMARKER OF HARM DUE TO EXPOSURE TO CIGARETTE SMOKE. 2013 18 1579 33 DNA METHYLATION PROFILE OF LIVER OF MICE CONCEIVED BY IN VITRO FERTILIZATION. OFFSPRING GENERATED BY IN VITRO FERTILIZATION (IVF) ARE BELIEVED TO BE HEALTHY BUT DISPLAY A POSSIBLE PREDISPOSITION TO CHRONIC DISEASES, LIKE HYPERTENSION AND GLUCOSE INTOLERANCE. SINCE EPIGENETIC CHANGES ARE BELIEVED TO UNDERLIE SUCH PHENOTYPE, THIS STUDY AIMED AT DESCRIBING GLOBAL DNA METHYLATION CHANGES IN THE LIVER OF ADULT MICE GENERATED BY NATURAL MATING (FB GROUP) OR BY IVF. EMBRYOS WERE GENERATED BY IVF OR NATURAL MATING. AT 30 WEEKS OF AGE, MICE WERE SACRIFICED. THE LIVER WAS REMOVED, AND GLOBAL DNA METHYLATION WAS ASSESSED USING WHOLE-GENOME BISULFITE SEQUENCING (WGBS). GENOMIC REGIONS FOR ENRICHMENT ANALYSIS TOOL (GREAT) AND G:PROFILERBETA WERE USED TO IDENTIFY DIFFERENTIALLY METHYLATED REGIONS (DMRS) AND FOR FUNCTIONAL ENRICHMENT ANALYSIS. OVERREPRESENTED GENE ONTOLOGY TERMS WERE SUMMARIZED WITH REVIGO, WHILE CANONICAL PATHWAYS (CPS) WERE IDENTIFIED WITH INGENUITY(R) PATHWAY ANALYSIS. OVERALL, 2692 DMRS (4.91%) WERE DIFFERENT BETWEEN THE GROUPS. THE MAJORITY OF DMRS (84.92%) WERE HYPOMETHYLATED IN THE IVF GROUP. SURPRISINGLY, ONLY 0.16% OF CPG ISLANDS WERE DIFFERENTIALLY METHYLATED AND ONLY A FEW DMRS WERE LOCATED ON KNOWN GENE PROMOTERS (N = 283) OR ENHANCERS (N = 190). NOTABLY, THE LONG-INTERSPERSED ELEMENT (LINE), SHORT-INTERSPERSED ELEMENT (SINE), AND LONG TERMINAL REPEAT (LTR1) TRANSPOSABLE ELEMENTS SHOWED REDUCED METHYLATION (P < 0.05) IN IVF LIVERS. CELLULAR METABOLIC PROCESS, HEPATIC FIBROSIS, AND INSULIN RECEPTOR SIGNALING WERE SOME OF THE PRINCIPAL BIOLOGICAL PROCESSES AND CPS MODIFIED BY IVF. IN SUMMARY, IVF MODIFIES THE DNA METHYLATION SIGNATURE IN THE ADULT LIVER, RESULTING IN HYPOMETHYLATION OF GENES INVOLVED IN METABOLISM AND GENE TRANSCRIPTION REGULATION. THESE FINDINGS MAY SHED LIGHT ON THE MECHANISMS UNDERLYING THE DEVELOPMENTAL ORIGIN OF HEALTH AND DISEASE. 2022 19 3658 35 INDUCTION OF ABERRANT TRIMETHYLATION OF HISTONE H3 LYSINE 27 BY INFLAMMATION IN MOUSE COLONIC EPITHELIAL CELLS. A FIELD FOR CANCERIZATION (FIELD DEFECT), WHERE GENETIC AND EPIGENETIC ALTERATIONS ARE ACCUMULATED IN NORMAL-APPEARING TISSUES, IS INVOLVED IN HUMAN CARCINOGENESIS, ESPECIALLY CANCERS ASSOCIATED WITH CHRONIC INFLAMMATION. ALTHOUGH ABERRANT DNA METHYLATION IS INVOLVED IN THE FIELD DEFECT AND INDUCED BY CHRONIC INFLAMMATION, IT IS STILL UNCLEAR FOR TRIMETHYLATION OF HISTONE H3 LYSINE 27 (H3K27ME3), WHICH IS INVOLVED IN GENE REPRESSION INDEPENDENT OF DNA METHYLATION AND FUNCTIONS AS A PRE-MARK FOR ABERRANT DNA METHYLATION. IN THIS STUDY, USING A MOUSE COLITIS MODEL INDUCED BY DEXTRAN SULFATE SODIUM (DSS), WE AIMED TO CLARIFY WHETHER ABERRANT H3K27ME3 IS INDUCED BY INFLAMMATION AND INVOLVED IN A FIELD DEFECT. CHIP-ON-CHIP ANALYSIS OF COLONIC EPITHELIAL CELLS REVEALED THAT H3K27ME3 LEVELS WERE INCREASED OR DECREASED FOR 266 GENOMIC REGIONS BY AGING, AND MORE EXTENSIVELY (23 INCREASED AND 3574 DECREASED REGIONS) BY COLITIS. SUCH INCREASE OR DECREASE OF H3K27ME3 WAS INDUCED AS EARLY AS 2 WEEKS AFTER THE INITIATION OF DSS TREATMENT, AND PERSISTED AT LEAST FOR 16 WEEKS EVEN AFTER THE INFLAMMATION DISAPPEARED. SOME OF THE ABERRANT H3K27ME3 IN COLONIC EPITHELIAL CELLS WAS CARRIED OVER INTO COLON TUMORS. FURTHERMORE, H3K27ME3 ACQUIRED AT DAPK1 BY COLITIS WAS FOLLOWED BY INCREASED DNA METHYLATION, SUPPORTING ITS FUNCTION AS A PRE-MARK FOR ABERRANT DNA METHYLATION. THESE RESULTS DEMONSTRATED THAT ABERRANT H3K27ME3 CAN BE INDUCED BY EXPOSURE TO A SPECIFIC ENVIRONMENT, SUCH AS COLITIS, AND SUGGESTED THAT ABERRANT HISTONE MODIFICATION, IN ADDITION TO ABERRANT DNA METHYLATION, IS INVOLVED IN THE FORMATION OF A FIELD DEFECT. 2012 20 2957 23 GENETIC AND EPIGENETIC IMPACT OF CHRONIC INFLAMMATION ON COLON MUCOSA CELLS. CHRONIC INFLAMMATION INCREASES CANCER RISK, AND CANCER DEVELOPMENT IS CHARACTERIZED BY STEPWISE ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS. DURING CHRONIC INFLAMMATION, INFECTIOUS AGENTS AND INTRINSIC MEDIATORS OF INFLAMMATORY RESPONSES CAN INDUCE GENETIC AND EPIGENETIC CHANGES. THIS STUDY TRIED TO EVALUATE BOTH THE GENETIC AND EPIGENETIC INFLUENCE OF CHRONIC INFLAMMATION ON COLON MUCOSA CELLS. REPETITIVE DEXTRAN SULFATE SODIUM (DSS) TREATMENT INDUCED CHRONIC COLITIS MODEL. WHOLE-EXOME SEQUENCING (WES) (200X COVERAGE) WAS PERFORMED TO DETECT SOMATIC VARIATIONS IN COLON MUCOSA CELLS. WITH THE USE OF WHOLE-GENOME BISULFITE SEQUENCING (BS) AT 34-FOLD COVERAGE (17-FOLD PER STRAND), THE METHYLOME OF BOTH THE COLITIS AND CONTROL TISSUE WAS COMPARATIVELY ANALYZED. BIOINFORMATICS ASSAY SHOWED THAT THERE WAS NO SIGNIFICANT SINGLE-NUCLEOTIDE POLYMORPHISM/INSERTION OR DELETION (SNP/INDEL) MUTATION ACCUMULATION IN COLITIS TISSUE, WHILE IT ACCUMULATED IN AGED MICE. FORTY-EIGHT GENES WITH SNP/INDEL MUTATION WERE OVERLAPPED IN THE THREE COLITIS TISSUES, TWO (WNT3A AND LAMA2) OF WHICH ARE IN THE CANCER DEVELOPMENT-RELATED SIGNALING PATHWAY. DIFFERENTIALLY METHYLATED REGION (DMR) ASSAY SHOWED THAT MANY GENES IN THE COLITIS TISSUE ARE ENRICHED IN THE CANCER DEVELOPMENT-RELATED SIGNALING PATHWAY, SUCH AS PI3K-AKT, RAS, WNT, TGF-BETA, AND MAPK SIGNALING PATHWAY. TOGETHER, THESE DATA SUGGESTED THAT EVEN THOUGH CHRONIC INFLAMMATION DID NOT OBVIOUSLY INCREASE GENETIC MUTATION ACCUMULATION, IT COULD BOTH GENETICALLY AND EPIGENETICALLY ALTER SOME GENES RELATED TO CANCER DEVELOPMENT. 2021