1 1353 147 DEVELOPMENT AND CHARACTERIZATION OF A HYDROGEN PEROXIDE-RESISTANT CHOLANGIOCYTE CELL LINE: A NOVEL MODEL OF OXIDATIVE STRESS-RELATED CHOLANGIOCARCINOMA GENESIS. OXIDATIVE STRESS IS A CAUSE OF INFLAMMATION-RELATED DISEASES, INCLUDING CANCERS. CHOLANGIOCARCINOMA IS A LIVER CANCER WITH BILE DUCT EPITHELIAL CELL PHENOTYPES. OUR PREVIOUS STUDIES IN ANIMAL AND HUMAN MODELS INDICATED THAT OXIDATIVE STRESS IS A MAJOR CAUSE OF CHOLANGIOCARCINOMA DEVELOPMENT. HYDROGEN PEROXIDE (H2O2) CAN GENERATE HYDROXYL RADICALS, WHICH DAMAGE LIPIDS, PROTEINS, AND NUCLEIC ACIDS, LEADING TO CELL DEATH. HOWEVER, SOME CELLS CAN SURVIVE BY ADAPTING TO OXIDATIVE STRESS CONDITIONS, AND SELECTIVE CLONAL EXPANSION OF THESE RESISTANT CELLS WOULD BE INVOLVED IN OXIDATIVE STRESS-RELATED CARCINOGENESIS. THE PRESENT STUDY AIMED TO ESTABLISH H2O2-RESISTANT CELL LINE FROM AN IMMORTAL CHOLANGIOCYTE CELL LINE (MMNK1) BY CHRONIC TREATMENT WITH LOW-CONCENTRATION H2O2 (25 MUM). AFTER 72 DAYS OF INDUCTION, H2O2-RESISTANT CELL LINES (OX-MMNK1-L) WERE OBTAINED. THE OX-MMNK1-L CELL LINE SHOWED H2O2-RESISTANT PROPERTIES, INCREASING THE EXPRESSION OF THE ANTI-OXIDANT GENES CATALASE (CAT), SUPEROXIDE DISMUTASE-1 (SOD1), SUPEROXIDE DISMUTASE-2 (SOD2), AND SUPEROXIDE DISMUTASE-3 (SOD3) AND THE ENZYME ACTIVITIES OF CAT AND INTRACELLULAR SODS. FURTHERMORE, THE RESISTANT CELLS SHOWED INCREASED EXPRESSION LEVELS OF AN EPIGENETICS-RELATED GENE, DNA METHYLTRANSFERASE-1 (DNMT1), WHEN COMPARED TO THE PARENTAL CELLS. INTERESTINGLY, THE OX-MMNK1-L CELL LINE HAD A SIGNIFICANTLY HIGHER CELL PROLIFERATION RATE THAN THE MMNK1 NORMAL CELL LINE. MOREOVER, OX-MMNK1-L CELLS SHOWED PSEUDOPODIA FORMATION AND THE LOSS OF CELL-TO-CELL ADHESION (MULTI-LAYERS) UNDER ADDITIONAL OXIDATIVE STRESS (100 MUM H2O2). THESE FINDINGS SUGGEST THAT H2O2-RESISTANT CELLS CAN BE USED AS A MODEL OF OXIDATIVE STRESS-RELATED CHOLANGIOCARCINOMA GENESIS THROUGH MOLECULAR CHANGES SUCH AS ALTERATION OF GENE EXPRESSION AND EPIGENETIC CHANGES. 2015 2 3468 40 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 3 222 32 ACUTE LIVER STEATOSIS TRANSLATIONALLY CONTROLS THE EPIGENETIC REGULATOR MIER1 TO PROMOTE LIVER REGENERATION IN A STUDY WITH MALE MICE. THE EARLY PHASE LIPID ACCUMULATION IS ESSENTIAL FOR LIVER REGENERATION. HOWEVER, WHETHER THIS ACUTE LIPID ACCUMULATION CAN SERVE AS SIGNALS TO DIRECT LIVER REGENERATION RATHER THAN SIMPLY PROVIDING BUILDING BLOCKS FOR CELL PROLIFERATION REMAINS UNCLEAR. THROUGH IN VIVO CRISPR SCREENING, WE IDENTIFY MIER1 (MESODERM INDUCTION EARLY RESPONSE 1) AS A KEY EPIGENETIC REGULATOR THAT BRIDGES THE ACUTE LIPID ACCUMULATION AND CELL CYCLE GENE EXPRESSION DURING LIVER REGENERATION IN MALE ANIMALS. PHYSIOLOGICALLY, LIVER ACUTE LIPID ACCUMULATION INDUCES THE PHOSPHORYLATION OF EIF2S1(EUKARYOTIC TRANSLATION INITIATION FACTOR 2), WHICH CONSEQUENTLY ATTENUATED MIER1 TRANSLATION. MIER1 DOWNREGULATION IN TURN PROMOTES CELL CYCLE GENE EXPRESSION AND REGENERATION THROUGH CHROMATIN REMODELING. IMPORTANTLY, THE LIPIDS-EIF2S1-MIER1 PATHWAY IS IMPAIRED IN ANIMALS WITH CHRONIC LIVER STEATOSIS; WHEREAS MIER1 DEPLETION SIGNIFICANTLY IMPROVES REGENERATION IN THESE ANIMALS. TAKEN TOGETHER, OUR STUDIES IDENTIFY AN EPIGENETIC MECHANISM BY WHICH THE EARLY PHASE LIPID REDISTRIBUTION FROM ADIPOSE TISSUE TO LIVER DURING REGENERATION IMPACTS HEPATOCYTE PROLIFERATION, AND SUGGEST A POTENTIAL STRATEGY TO BOOST LIVER REGENERATION. 2023 4 3723 39 INHIBITION OF DNA METHYLTRANSFERASE OR HISTONE DEACETYLASE PROTECTS RETINAL PIGMENT EPITHELIAL CELLS FROM DNA DAMAGE INDUCED BY OXIDATIVE STRESS BY THE STIMULATION OF ANTIOXIDANT ENZYMES. EPIGENETIC MODIFICATIONS INFLUENCE DNA DAMAGE RESPONSE (DDR). IN THIS STUDY WE EXPLORED THE ROLE OF DNA METHYLATION AND HISTONE ACETYLATION IN DDR IN CELLS CHALLENGED WITH ACUTE OR CHRONIC OXIDATIVE STRESS. WE USED RETINAL PIGMENT EPITHELIAL CELLS (ARPE-19), WHICH NATIVELY ARE EXPOSED TO OXIDATIVE STRESS DUE TO PERMANENT EXPOSURE TO LIGHT AND HIGH BLOOD FLOW. WE EMPLOYED A DNA METHYLTRANSFERASE INHIBITOR - RG108 (RG), OR A HISTONE DEACETYLASE INHIBITOR - VALPROIC ACID (VA). ARPE-19 CELLS WERE EXPOSED TO TERT-BUTYL HYDROPEROXIDE, AN ACUTE OXIDATIVE STRESS INDUCER, OR GLUCOSE OXIDASE, WHICH SLOWLY LIBERATES LOW-DOSES OF HYDROGEN PEROXIDE IN THE PRESENCE OF GLUCOSE, CREATING CHRONIC CONDITIONS. VA AND RG REDUCED LEVEL OF INTRACELLULAR REACTIVE OXYGEN SPECIES AND DNA DAMAGE IN ARPE-19 CELLS IN NORMAL CONDITION AND IN OXIDATIVE STRESS. THIS PROTECTIVE EFFECT OF VA AND RG WAS ASSOCIATED WITH THE UP-REGULATED EXPRESSION OF ANTIOXIDANT ENZYME GENES: CAT, GPX1, GPX4, SOD1 AND SOD2. RG DECREASED THE NUMBER OF CELLS IN G2/M CHECKPOINT IN RESPONSE TO CHRONIC OXIDATIVE STRESS. NEITHER RG NOR VA CHANGED THE DNA REPAIR OR APOPTOSIS INDUCED BY OXIDATIVE STRESS. THEREFORE, CERTAIN EPIGENETIC MANIPULATIONS MAY PROTECT ARPE-19 CELLS FROM DETRIMENTAL EFFECTS OF OXIDATIVE STRESS BY MODULATION OF ANTIOXIDATIVE ENZYME GENE EXPRESSION, WHICH MAY BE FURTHER EXPLORED IN PHARMACOLOGICAL STUDIES ON OXIDATIVE STRESS-RELATED EYE DISEASES. 2016 5 1966 31 EPIGENETIC ALTERATION OF PRKCDBP IN COLORECTAL CANCERS AND ITS IMPLICATION IN TUMOR CELL RESISTANCE TO TNFALPHA-INDUCED APOPTOSIS. PURPOSE: PRKCDBP IS A PUTATIVE TUMOR SUPPRESSOR IN WHICH ALTERATION HAS BEEN OBSERVED IN SEVERAL HUMAN CANCERS. WE INVESTIGATED EXPRESSION AND FUNCTION OF PRKCDBP IN COLORECTAL CELLS AND TISSUES TO EXPLORE ITS CANDIDACY AS A SUPPRESSOR IN COLORECTAL TUMORIGENESIS. EXPERIMENTAL DESIGN: EXPRESSION AND METHYLATION STATUS OF PRKCDBP AND ITS EFFECT ON TUMOR GROWTH WERE EVALUATED. TRANSCRIPTIONAL REGULATION BY NF-KAPPAB SIGNALING WAS DEFINED BY LUCIFERASE REPORTER AND CHROMATIN IMMUNOPRECIPITATION ASSAYS. RESULTS: PRKCDBP EXPRESSION WAS HARDLY DETECTABLE IN 29 OF 80 (36%) PRIMARY TUMORS AND 11 OF 19 (58%) CELL LINES, AND ITS ALTERATION CORRELATED WITH TUMOR STAGE AND GRADE. PROMOTER HYPERMETHYLATION WAS COMMONLY FOUND IN CANCERS. PRKCDBP EXPRESSION INDUCED THE G(1) CELL-CYCLE ARREST AND INCREASED CELLULAR SENSITIVITY TO VARIOUS APOPTOTIC STRESSES. PRKCDBP WAS INDUCED BY TNFALPHA, AND ITS LEVEL CORRELATED WITH TUMOR CELL SENSITIVITY TO TNFALPHA-INDUCED APOPTOSIS. PRKCDBP INDUCTION BY TNFALPHA WAS DISRUPTED BY BLOCKING NF-KAPPAB SIGNALING WHILE IT WAS ENHANCED BY RELA TRANSFECTION. THE PRKCDBP PROMOTER ACTIVITY WAS INCREASED IN RESPONSE TO TNFALPHA, AND THIS RESPONSE WAS ABOLISHED BY DISRUPTION OF A KAPPAB SITE IN THE PROMOTER. PRKCDBP DELAYED THE FORMATION AND GROWTH OF XENOGRAFT TUMORS AND IMPROVED TUMOR RESPONSE TO TNFALPHA-INDUCED APOPTOSIS. CONCLUSIONS: PRKCDBP IS A PROAPOPTOTIC TUMOR SUPPRESSOR WHICH IS COMMONLY ALTERED IN COLORECTAL CANCER BY PROMOTER HYPERMETHYLATION, AND ITS GENE TRANSCRIPTION IS DIRECTLY ACTIVATED BY NF-KAPPAB IN RESPONSE TO TNFALPHA. THIS SUGGESTS THAT PRKCDBP INACTIVATION MAY CONTRIBUTE TO TUMOR PROGRESSION BY REDUCING CELLULAR SENSITIVITY TO TNFALPHA AND OTHER STRESSES, PARTICULARLY UNDER CHRONIC INFLAMMATORY MICROENVIRONMENT. 2011 6 5785 36 SPONTANEOUS NEOPLASTIC TRANSFORMATION OF WB-F344 RAT LIVER EPITHELIAL CELLS. SEVERAL STUDIES HAVE SHOWN THAT CULTURED RAT LIVER EPITHELIAL CELLS TRANSFORM SPONTANEOUSLY AFTER CHRONIC MAINTENANCE IN A CONFLUENT STATE IN VITRO. IN THE PRESENT STUDY, MULTIPLE INDEPENDENT LINEAGES OF LOW-PASSAGE WB-F344 RAT LIVER EPITHELIAL STEM-LIKE CELLS WERE INITIATED AND SUBJECTED IN PARALLEL TO SELECTION FOR SPONTANEOUS TRANSFORMATION TO DETERMINE WHETHER SPONTANEOUS ACQUISITION OF TUMORIGENICITY WAS THE RESULT OF EVENTS (GENETIC OR EPIGENETIC) THAT OCCURRED INDEPENDENTLY AND STOCHASTICALLY, OR REFLECTED THE EXPRESSION OF A PRE-EXISTING ALTERATION WITHIN THE PARENTAL WB-F344 CELL LINE. TEMPORAL ANALYSIS OF THE SPONTANEOUS ACQUISITION OF TUMORIGENICITY BY WB-F344 CELLS DEMONSTRATED LINEAGE-SPECIFIC DIFFERENCES IN THE TIME OF FIRST EXPRESSION OF THE TUMORIGENIC PHENOTYPE, FREQUENCIES AND LATENCIES OF TUMOR FORMATION, AND TUMOR DIFFERENTIATIONS. ALTHOUGH SPONTANEOUSLY TRANSFORMED WB-F344 CELLS PRODUCED DIVERSE TUMOR TYPES (INCLUDING HEPATOCELLULAR CARCINOMAS, CHOLANGIOCARCINOMAS, HEPATOBLASTOMAS, AND OSTEOGENIC SARCOMAS), INDIVIDUAL LINEAGES YIELDED TUMORS WITH CONSISTENT AND SPECIFIC PATTERNS OF DIFFERENTIATION. THESE RESULTS PROVIDE SUBSTANTIAL EVIDENCE THAT THE STOCHASTIC ACCUMULATION OF INDEPENDENT TRANSFORMING EVENTS DURING THE SELECTION REGIMEN IN VITRO WERE RESPONSIBLE FOR SPONTANEOUS NEOPLASTIC TRANSFORMATION OF WB-F344 CELLS. FURTHERMORE, CELL LINEAGE COMMITMENT TO A SPECIFIC DIFFERENTIATION PROGRAM WAS STABLE WITH TIME IN CULTURE AND WITH SITE OF TRANSPLANTATION. THIS IS THE FIRST REPORT OF A COHORT OF RELATED, BUT INDEPENDENT, RAT LIVER EPITHELIAL CELL LINES THAT COLLECTIVELY PRODUCE A SPECTRUM OF TUMOR TYPES BUT INDIVIDUALLY REPRODUCE A SPECIFIC TUMOR TYPE. THESE CELL LINES WILL PROVIDE VALUABLE REAGENTS FOR INVESTIGATION OF THE MOLECULAR MECHANISMS INVOLVED IN THE DIFFERENTIATION OF HEPATIC STEM-LIKE CELLS AND FOR EXAMINATION OF POTENTIAL CAUSAL RELATIONSHIPS IN SPONTANEOUSLY TRANSFORMED RAT LIVER EPITHELIAL CELL LINES BETWEEN MOLECULAR/CELLULAR ALTERATIONS AND THE ABILITY TO PRODUCE TUMORS IN SYNGENEIC ANIMALS. 1998 7 19 37 5-AZACYTYDINE AND RESVERATROL REVERSE SENESCENCE AND AGEING OF ADIPOSE STEM CELLS VIA MODULATION OF MITOCHONDRIAL DYNAMICS AND AUTOPHAGY. OBESITY AND ENDOCRINE DISORDERS HAVE BECOME PREVALENT ISSUES IN THE FIELD OF BOTH HUMAN AND VETERINARY MEDICINE. EQUINE METABOLIC SYNDROME IS A COMPLEX DISORDER INVOLVING ALTERNATION IN METABOLISM AND CHRONIC SYSTEMIC INFLAMMATION. IT HAS BEEN SHOWN THAT UNFAVOURABLE MICROENVIRONMENT OF INFLAMED ADIPOSE TISSUE NEGATIVELY AFFECTS ADIPOSE STEM CELL POPULATION (ASC) RESIDING WITHIN, MARKEDLY LIMITING THEIR THERAPEUTIC POTENTIAL. ASCS(EMS) ARE CHARACTERIZED BY INCREASED SENESCENCE APOPTOSIS, EXCESSIVE ACCUMULATION OF REACTIVE OXYGEN SPECIES (ROS), MITOCHONDRIA DETERIORATION AND "AUTOPHAGIC FLUX." THE AIM OF THE PRESENT STUDY WAS TO EVALUATE WHETHER TREATMENT OF ASCS(EMS) WITH A COMBINATION OF 5-AZACYTYDINE (AZA) AND RESVERATROL (RES) WOULD REVERSE AGED PHENOTYPE OF THESE CELLS. FOR THIS REASON, WE PERFORMED THE FOLLOWING ANALYZES: MOLECULAR BIOLOGY (RT-PCR), MICROSCOPIC (IMMUNOFLUORESCENCE, TEM) AND FLOW CYTOMETRY (JC-1, ROS, KI67). WE EVALUATED THE MITOCHONDRIAL STATUS, DYNAMICS AND CLEARANCE AS WELL AS AUTOPHAGIC PATHWAYS. FURTHERMORE, WE INVESTIGATED EPIGENETIC ALTERNATIONS IN TREATED CELLS BY MEASURING THE EXPRESSION OF TET GENES AND ANALYSIS OF DNA METHYLATION STATUS. WE HAVE DEMONSTRATED THAT AZA/RES TREATMENT OF ASCS(EMS) IS ABLE TO REJUVENATE THESE CELLS BY MODULATING MITOCHONDRIAL DYNAMICS, IN PARTICULAR BY PROMOTING MITOCHONDRIAL FUSION OVER FISSION. AFTER AZA/RES TREATMENT, ASCS(EMS) WERE CHARACTERIZED BY INCREASED PROLIFERATION RATE, DECREASED APOPTOSIS AND SENESCENCE AND LOWER ROS ACCUMULATION. OUR FINDINGS OFFER A NOVEL APPROACH AND POTENTIAL TARGETS FOR THE BENEFICIAL EFFECTS OF AZA/RES IN AMELIORATING STEM CELL DYSFUNCTIONS. 2019 8 194 34 ACETYLSHIKONIN SUPPRESSES INVASION OF PORPHYROMONAS GINGIVALIS?INFECTED YD10B ORAL CANCER CELLS BY MODULATING THE INTERLEUKIN-8/MATRIX METALLOPROTEINASE AXIS. THE DEVELOPMENT OF PHARMACEUTICAL AGENTS POSSESSING ANTI?INVASIVE AND ANTI?METASTATIC ABILITIES, AS WELL AS APOPTOTIC ACTIVITY, IS IMPORTANT IN DECREASING THE INCIDENCE AND RECURRENCE OF ORAL CANCER. CANCER CELLS ARE KNOWN TO ACQUIRE INVASIVENESS NOT ONLY THROUGH EPIGENETIC CHANGES, BUT ALSO FROM INFLAMMATORY STIMULI WITHIN THE TUMOR MICROENVIRONMENT. ACCORDINGLY, THE IDENTIFICATION OF AGENTS THAT CAN SUPPRESS THE INFLAMMATION?PROMOTED INVASIVENESS OF CANCER CELLS MAY BE IMPORTANT IN TREATING CANCER AND IMPROVING THE PROGNOSIS OF PATIENTS WITH CANCER. ACETYLSHIKONIN, A FLAVONOID WITH ANTI?INFLAMMATORY ACTIVITY, INHIBITS PROLIFERATION AND INDUCES APOPTOSIS OF ORAL CANCER CELLS. IN THE PRESENT STUDY, THE ANTI?INVASIVE EFFECT OF ACETYLSHIKONIN ON YD10B ORAL CANCER CELLS INFECTED WITH PORPHYROMONAS GINGIVALIS, A MAJOR PATHOGEN OF CHRONIC PERIODONTITIS, AND THE MECHANISMS INVOLVED WERE INVESTIGATED. FIRSTLY, WE EXAMINED WHETHER P. GINGIVALIS INFECTION INCREASED THE INVASIVENESS OF YD10B CELLS. RESULTS SUGGESTED THAT YD10B ORAL CANCER CELLS BECOME MORE AGGRESSIVE WHEN THEY ARE INFECTED WITH P. GINGIVALIS. SECONDLY, ACETYLSHIKONIN SIGNIFICANTLY INHIBITED THE INVASION OF P. GINGIVALIS?INFECTED YD10B CELLS BY SUPPRESSING IL?8 RELEASE AND IL?8?DEPENDENT MMP RELEASE. THESE DATA SUGGEST THAT ACETYLSHIKONIN MAY BE A USEFUL PREVENTIVE AND THERAPEUTIC CANDIDATE FOR ORAL CANCER THAT IS CHRONICALLY INFECTED WITH PERIODONTAL PATHOGENS. 2018 9 1965 34 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 10 402 31 ANALYSIS OF APOPTOSOME DYSREGULATION IN PANCREATIC CANCER AND OF ITS ROLE IN CHEMORESISTANCE. THE APOPTOSOME IS A MULTIPROTEIN COMPLEX MEDIATING THE MITOCHONDRIAL PATHWAY OF CELL DEATH. ITS IMPORTANCE DURING DEVELOPMENT HAS BEEN CLEARLY DEMONSTRATED BY KNOCKING OUT KEY GENES IN MOUSE. APAF1 IS THE CORE PROTEIN OF THE APOPTOSOME AND ITS DOSAGE IS ALSO CRITICAL IN VARIOUS CANCER TYPES, I.E., MELANOMA, GERM LINE TUMOR, GASTROINTESTINAL CANCER AND B-TYPE CHRONIC LYMPHOCYTIC LEUKEMIA. THIS IS GENERALLY DUE TO INACTIVATION OF THE APAF1 LOCUS BY EPIGENETIC PHENOMENA OR BY ACTIVITY OF PROMOTER REGULATORS. WE INVESTIGATED THE PUTATIVE ROLES OF THE APOPTOSOME IN PANCREATIC DUCTAL ADENOCARCINOMA (PDAC). WE FOUND THAT BOTH APAF1 MRNA AND PROTEIN ARE DYSREGULATED IN HUMAN PDAC SAMPLES. SIMILARLY, SEVERAL PDAC CELL LINES EXHIBITED VARIABLE LEVELS OF BOTH APAF1 PROTEIN AND MRNA. THE RESPONSE TO CELL DEATH INDUCTION AND ITS BIOCHEMICAL FEATURES WERE ASSESSED BY TREATMENT OF EACH LINE WITH COMMONLY USED CHEMOTHERAPEUTIC AGENTS. WE FOUND THAT THE APOPTOSOME PATHWAY WAS NOT FUNCTIONAL IN MOST CELL LINES UPON CYTOCHROME C RELEASE FROM MITOCHONDRIA. IN ADDITION, WE RESTORED APAF1 AND CASPASE-9 DOSAGE IN PANC-1 CELLS, WHERE THE APOPTOSOME IS DOWNREGULATED, BY OVEREXPRESSING THE MURINE CDNA OF THE TWO MOLECULES, AND WE IMPROVED THE DEATH RESPONSE TO CHEMOTHERAPEUTIC AGENTS. 2007 11 3243 33 HEPATIC STEATOSIS IN HEPATITIS C IS A STORAGE DISEASE DUE TO HCV INTERACTION WITH MICROSOMAL TRIGLYCERIDE TRANSFER PROTEIN (MTP). LIVER STEATOSIS IS A FREQUENT HISTOLOGICAL FEATURE IN PATIENTS CHRONICALLY INFECTED WITH HEPATITIS C VIRUS (HCV). THE RELATIONSHIP BETWEEN HCV AND HEPATIC STEATOSIS SEEMS TO BE THE RESULT OF BOTH EPIGENETIC AND GENETIC FACTORS. IN VIVO AND IN VITRO STUDIES HAVE SHOWN THAT HCV CAN ALTER INTRAHEPATIC LIPID METABOLISM BY AFFECTING LIPID SYNTHESIS, OXIDATIVE STRESS, LIPID PEROXIDATION, INSULIN RESISTANCE AND THE ASSEMBLY AND SECRETION OF VLDL. MANY STUDIES SUGGEST THAT HCV-RELATED STEATOSIS MIGHT BE THE RESULT OF A DIRECT INTERACTION BETWEEN THE VIRUS AND MTP. IT HAS BEEN DEMONSTRATED THAT MTP IS CRITICAL FOR THE SECRETION OF HCV PARTICLES AND THAT INHIBITION OF ITS LIPID TRANSFER ACTIVITY REDUCES HCV PRODUCTION. HOWEVER, HIGHER DEGREES OF HEPATIC STEATOSIS WERE FOUND IN CHRONIC HEPATITIS C PATIENTS CARRYING THE T ALLELE OF MTP -493G/T POLYMORPHISM THAT SEEMS TO BE ASSOCIATED WITH INCREASED MTP TRANSCRIPTION. WE PROPOSE HERE THAT LIVER STEATOSIS IN HEPATITIS C COULD BE A STORAGE DISEASE INDUCED BY THE EFFECTS OF THE VIRUS AND OF ITS PROTEINS ON THE INTRACELLULAR LIPID MACHINERY AND ON MTP. AVAILABLE DATA SUPPORT THE HYPOTHESIS THAT HCV MAY MODULATE MTP EXPRESSION AND ACTIVITY THROUGH A NUMBER OF MECHANISMS SUCH AS INHIBITION OF ITS ACTIVITY AND TRANSCRIPTIONAL CONTROL. INITIAL UP REGULATION COULD FAVOUR PROPAGATION OF HCV WHILE DOWN REGULATION IN CHRONIC PHASE COULD CAUSE IMPAIRMENT OF TRIGLYCERIDE SECRETION AND EXCESSIVE LIPID ACCUMULATION, WITH ABNORMAL LIPID DROPLETS FACILITATING THE "STORAGE" OF VIRUS PARTICLES FOR PERSISTENT INFECTION. 2010 12 5491 39 REVIEW ARTICLE: INFLAMMATION-RELATED PROMOTION OF GASTROINTESTINAL CARCINOGENESIS--A PERIGENETIC PATHWAY. CHRONIC INFLAMMATION HAS BEEN REPORTED TO ACCELERATE NEOPLASMAS IN GASTROINTESTINAL TRACT. CERTAIN BACTERIA INCLUDING HELICOBACTER PYLORI DIRECTLY INTERACT WITH HOST CELLS, INDUCE PROINFLAMMATORY CYTOKINES AND STIMULATE PRODUCTION OF FREE RADICALS. FREE RADICALS CAUSE MUTATIONS IN TARGET CELLS SO THAT NEOPLASTIC CLONES ARE ESTABLISHED. ACCUMULATION OF SUCH GENETIC ALTERATIONS MAY CAUSE MALIGNANT TRANSFORMATION OF SOME ESTABLISHED CLONES. IN ADDITION, INFLAMMATORY ALTERATIONS MAY PROMOTE GROWTH, EXPANSION AND INVASION OF GASTROINTESTINAL EPITHELIAL CELLS. THE LATTER CHANGES CAUSED BY INFLAMMATION MAY OCCUR EVEN WITHOUT FURTHER GENETIC MUTATIONS OR EPIGENETIC ALTERATIONS, AND THEREFORE MAY BE CATEGORIZED AS 'PERIGENETIC ALTERATIONS' OF NEOPLASTIC CELLS. FOR AN EXAMPLE, TUMOUR NECROSIS FACTOR ALPHA (TNF-ALPHA) PLAYS PIVOTAL ROLES NOT ONLY IN THE REDUCTION BUT ALSO IN THE GROWTH, INVASION AND METASTASES OF CERTAIN NEOPLASMAS. OUR STUDIES SHOW THAT TNF-ALPHA INCREASES INTRACELLULAR RADICAL PRODUCTION, DEGRADATES E-CADHERIN / BETA-CATENIN COMPLEX AND PROMOTES DISPERSION AND MIGRATION IN EPITHELIAL CELLS TRANSFORMED WITH AN ACTIVATED SRC ONCOGENE (V-SRC). THESE DATA INDICATE THAT AN INFLAMMATORY CYTOKINE INDUCES THE MALIGNANT POTENTIAL OF SRC-ACTIVATED NEOPLASTIC CELLS. INTERESTINGLY, TNF-ALPHA ALSO INDUCED THESE PHENOTYPIC CHANGES IN NONMUTATED CELLS WHOSE C-SRC WAS ACTIVATED BY TGF-ALPHA, SUGGESTING THAT THE INVASIVE PROPERTIES OF THE CELL WERE NOT NECESSARILY RELATED TO GENE MUTATION. FURTHERMORE, CERTAIN RADICAL SCAVENGERS SUPPRESSED THE INVASIVE PHENOTYPE OF THE CELLS. THESE RESULTS INDICATE THAT PERIGENETIC ALTERATIONS ARE AN IMPORTANT TARGET OF PHARMACOLOGICAL INTERVENTION OF CARCINOGENESIS. 2003 13 984 36 CHRONIC PSYCHOLOGICAL STRESS ALTERS GENE EXPRESSION IN RAT COLON EPITHELIAL CELLS PROMOTING CHROMATIN REMODELING, BARRIER DYSFUNCTION AND INFLAMMATION. CHRONIC STRESS IS COMMONLY ASSOCIATED WITH ENHANCED ABDOMINAL PAIN (VISCERAL HYPERSENSITIVITY), BUT THE CELLULAR MECHANISMS UNDERLYING HOW CHRONIC STRESS INDUCES VISCERAL HYPERSENSITIVITY ARE POORLY UNDERSTOOD. IN THIS STUDY, WE EXAMINED CHANGES IN GENE EXPRESSION IN COLON EPITHELIAL CELLS FROM A RAT MODEL USING RNA-SEQUENCING TO EXAMINE STRESS-INDUCED CHANGES TO THE TRANSCRIPTOME. FOLLOWING CHRONIC STRESS, THE MOST SIGNIFICANTLY UP-REGULATED GENES INCLUDED ATG16L1, COQ10B, DCAF13, NAT2, PTBP2, RRAS2, SPINK4 AND DOWN-REGULATED GENES INCLUDING ABAT, CITED2, CNNM2, DAB2IP, PLEKHM1, SCD2, AND TAB2. THE PRIMARY ALTERED BIOLOGICAL PROCESSES REVEALED BY NETWORK ENRICHMENT ANALYSIS WERE INFLAMMATION/IMMUNE RESPONSE, TISSUE MORPHOGENESIS AND DEVELOPMENT, AND NUCLEOSOME/CHROMATIN ASSEMBLY. THE MOST SIGNIFICANTLY DOWN-REGULATED PROCESS WAS THE DIGESTIVE SYSTEM DEVELOPMENT/FUNCTION, WHEREAS THE MOST SIGNIFICANTLY UP-REGULATED PROCESSES WERE INFLAMMATORY RESPONSE, ORGANISMAL INJURY, AND CHROMATIN REMODELING MEDIATED BY H3K9 METHYLATION. FURTHERMORE, A SUBPOPULATION OF STRESSED RATS DEMONSTRATED VERY SIGNIFICANTLY ALTERED GENE EXPRESSION AND TRANSCRIPT ISOFORMS, ENRICHED FOR THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN THE INFLAMMATORY RESPONSE, INCLUDING UPREGULATION OF CYTOKINE AND CHEMOKINE RECEPTOR GENE EXPRESSION COUPLED WITH DOWNREGULATION OF EPITHELIAL ADHERENS AND TIGHT JUNCTION MRNAS. IN SUMMARY, THESE FINDINGS SUPPORT THAT CHRONIC STRESS IS ASSOCIATED WITH INCREASED LEVELS OF CYTOKINES AND CHEMOKINES, THEIR DOWNSTREAM SIGNALING PATHWAYS COUPLED TO DYSREGULATION OF INTESTINAL CELL DEVELOPMENT AND FUNCTION. EPIGENETIC REGULATION OF CHROMATIN REMODELING LIKELY PLAYS A PROMINENT ROLE IN THIS PROCESS. RESULTS ALSO SUGGEST THAT SUPER ENHANCERS PLAY A PRIMARY ROLE IN CHRONIC STRESS-ASSOCIATED INTESTINAL BARRIER DYSFUNCTION. 2022 14 1615 36 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 15 6421 32 THE THERAPEUTIC PROPERTIES OF RESMINOSTAT FOR HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON FORM OF PRIMARY LIVER CANCER WITH INCREASES IN NEW CASES BEING REPORTED ANNUALLY. HISTOPATHOLOGISTS HAVE IDENTIFIED HEPATIC STEATOSIS AS A CHARACTERISTIC OF A BROAD RANGE OF CHRONIC LIVER DISEASES THAT ARE ASSOCIATED WITH THE ONSET AND DEVELOPMENT OF HCC. IN THIS CONTEXT, EPIGENETIC MODIFICATIONS MAY SERVE AS PRECANCEROUS FACTORS PREDISPOSING NORMAL CELLS TO THE INITIATION OF CARCINOGENESIS. THIS STUDY DEMONSTRATED THAT HEPATIC TUMORIGENESIS AND DIFFERENTIATED ADIPOCYTES MAY MODULATE BOTH GLOBAL HISTONE DEACETYLASE (HDAC) EXPRESSION AND SPECIFIC CLASS I HDAC GENES IN THE TUMOUR MICROENVIRONMENT. THE NOVEL CLASS I HDAC INHIBITOR RESMINOSTAT WAS SHOWN TO REDUCE THE PROLIFERATION OF HCC CELLS ALONG WITH ITS SPECIFICITY IN TARGETING CLASS I HDACS AND ONCOGENES. THE COMBINED EFFECT OF RESMINOSTAT WITH SEVERAL PHARMACEUTICAL AGENTS SUCH AS SORAFENIB, CISPLATIN AND DOXORUBICIN WAS ALSO DEMONSTRATED. THE INHIBITION OF HEAT SHOCK PROTEIN 90 (HSP90) HAS BEEN DEMONSTRATED AS A POTENTIAL THERAPEUTIC OPTION FOR HCC. IN LINE WITH THIS, THE SPECIFIC HSP90 INHIBITOR 17-(ALLYLAMINO)-17-DEMETHOXYGELDANAMYCIN (17-AAG) WAS SELECTED AND IT WAS FOUND THAT THE COMBINATION OF RESMINOSTAT AND 17-AAG MAY PROVIDE A "SMART" CLINICAL STRATEGY FOR HCC PATIENTS BY TARGETING CELLULAR COMMUNICATION WITHIN THE TUMOUR MICROENVIRONMENT. THIS STUDY PROVIDES AN INSIGHT INTO THE USE OF RESMINOSTAT AS AN EPIGENETIC BASED THERAPEUTIC FOR HCC ALONG WITH OTHER PHARMACEUTICAL OPTIONS, IN PARTICULAR BY TARGETING THE CELL-TO-CELL COMMUNICATION THAT OCCURS BETWEEN HEPATOMA AND ADIPOCYTES. 2018 16 5468 37 RESISTANCE TRAINING AND REDOX HOMEOSTASIS: CORRELATION WITH AGE-ASSOCIATED GENOMIC CHANGES. REGULAR PHYSICAL ACTIVITY IS EFFECTIVE AS PREVENTION AND TREATMENT FOR DIFFERENT CHRONIC CONDITIONS RELATED TO THE AGEING PROCESSES. IN FACT, A SEDENTARY LIFESTYLE HAS BEEN LINKED TO A WORSENING OF CELLULAR AGEING BIOMARKERS SUCH AS TELOMERE LENGTH (TL) AND/OR SPECIFIC EPIGENETIC CHANGES (E.G. DNA METHYLATION), WITH INCREASE OF THE PROPENSITY TO AGING-RELATED DISEASES AND PREMATURE DEATH. EXTENDING OUR PREVIOUS FINDINGS, WE AIMED TO TEST THE HYPOTHESIS THAT 12 WEEKS OF LOW FREQUENCY, MODERATE INTENSITY, EXPLOSIVE-TYPE RESISTANCE TRAINING (EMRT) MAY ATTENUATE AGE-ASSOCIATED GENOMIC CHANGES. TO THIS AIM, TL, GLOBAL DNA METHYLATION, TRF2, KU80, SIRT1, SIRT2 AND GLOBAL PROTEIN ACETYLATION, AS WELL AS OTHER PROTEINS INVOLVED IN APOPTOTIC PATHWAY (BCL-2, BAX AND CASPASE-3), ANTIOXIDANT RESPONSE (TRXR1 AND MNSOD) AND OXIDATIVE DAMAGE (MYELOPEROXIDASE) WERE EVALUATED BEFORE AND AFTER EMRT IN WHOLE BLOOD OR PERIPHERAL MONONUCLEAR CELLS (PBMCS) OF ELDERLY SUBJECTS. OUR FINDINGS CONFIRM THE POTENTIAL OF EMRT TO INDUCE AN ADAPTIVE CHANGE IN THE ANTIOXIDANT PROTEIN SYSTEMS AT SYSTEMIC LEVEL AND SUGGEST A PUTATIVE ROLE OF RESISTANCE TRAINING IN THE REDUCTION OF GLOBAL DNA METHYLATION. MOREOVER, WE OBSERVED THAT EMRT COUNTERACTS THE TELOMERES' SHORTENING IN A MANNER THAT PROVED TO BE DIRECTLY CORRELATED WITH THE AMELIORATION OF REDOX HOMEOSTASIS AND EFFICACY OF TRAINING REGIME, EVALUATED AS IMPROVEMENT OF BOTH MUSCLE'S POWER/STRENGTH AND FUNCTIONAL PARAMETERS. 2016 17 2395 37 EPIGENETIC REPROGRAMMING IN MIST1(-/-) MICE PREDICTS THE MOLECULAR RESPONSE TO CERULEIN-INDUCED PANCREATITIS. GENE EXPRESSION IS AFFECTED BY MODIFICATIONS TO HISTONE CORE PROTEINS WITHIN CHROMATIN. CHANGES IN THESE MODIFICATIONS, OR EPIGENETIC REPROGRAMMING, CAN DICTATE CELL FATE AND PROMOTE SUSCEPTIBILITY TO DISEASE. THE GOAL OF THIS STUDY WAS TO DETERMINE THE EXTENT OF EPIGENETIC REPROGRAMMING IN RESPONSE TO CHRONIC STRESS THAT OCCURS FOLLOWING ABLATION OF MIST1 (MIST1(-/-) ), WHICH IS REPRESSED IN PANCREATIC DISEASE. CHROMATIN IMMUNOPRECIPITATION FOR TRIMETHYLATION OF LYSINE RESIDUE 4 ON HISTONE 3 (H3K4ME3) IN PURIFIED ACINAR CELLS FROM WILD TYPE AND MIST1(-/-) MICE WAS FOLLOWED BY NEXT GENERATION SEQUENCING (CHIP-SEQ) OR CHIP-QPCR. H3K4ME3-ENRICHED GENES WERE ASSESSED FOR EXPRESSION BY QRT-PCR IN PANCREATIC TISSUE BEFORE AND AFTER INDUCTION OF CERULEIN-INDUCED PANCREATITIS. WHILE MOST OF H3K4ME3-ENRICHMENT IS RESTRICTED TO TRANSCRIPTIONAL START SITES, >25% OF ENRICHMENT SITES ARE FOUND WITHIN, DOWNSTREAM OR BETWEEN ANNOTATED GENES. LESS THAN 10% OF THESE SITES WERE ALTERED IN MIST1(-/-) ACINI, WITH MOST CHANGES IN H3K4ME3 ENRICHMENT NOT REFLECTING ALTERED GENE EXPRESSION. INGENUITY PATHWAY ANALYSIS OF GENES DIFFERENTIALLY-ENRICHED FOR H3K4ME3 REVEALED AN ASSOCIATION WITH PANCREATITIS AND PANCREATIC DUCTAL ADENOCARCINOMA IN MIST1(-/-) TISSUE. MOST OF THESE GENES WERE NOT DIFFERENTIALLY EXPRESSED BUT SEVERAL WERE READILY INDUCED BY ACUTE EXPERIMENTAL PANCREATITIS, WITH SIGNIFICANTLY INCREASED EXPRESSION IN MIST1(-/-) TISSUE RELATIVE TO WILD TYPE MICE. WE SUGGEST THAT THE CHRONIC CELL STRESS OBSERVED IN THE ABSENCE OF MIST1 RESULTS IN EPIGENETIC REPROGRAMMING OF GENES INVOLVED IN PROMOTING PANCREATITIS TO A POISED STATE, THEREBY INCREASING THE SENSITIVITY TO EVENTS THAT PROMOTE DISEASE. 2014 18 3693 46 INFLAMMATORY CELLS CAN ALTER THE LEVELS OF H3K9AC AND GAMMAH2AX IN DYSPLASTIC CELLS AND FAVOR TUMOR PHENOTYPE. ORAL POTENTIALLY MALIGNANT DISORDERS (OPMD) ARE CLINICAL PRESENTATIONS THAT CARRY AN INCREASED RISK OF CANCER DEVELOPMENT. CURRENTLY, EPITHELIAL DYSPLASIA GRADE IS BASED ON ARCHITECTURAL AND CYTOLOGICAL EPITHELIAL CHANGES AND IS USED TO PREDICT THE MALIGNANT TRANSFORMATION OF THESE LESIONS. HOWEVER, PREDICTING WHICH OPMD WILL PROGRESS TO A MALIGNANT TUMOR IS VERY CHALLENGING. INFLAMMATORY INFILTRATES CAN FAVOR CANCER DEVELOPMENT, AND RECENT STUDIES SUGGEST THAT THIS ASSOCIATION WITH OPMD LESIONS MAY BE RELATED TO THE ETIOLOGY AND/OR AGGRESSIVE CLINICAL BEHAVIOR OF THESE LESIONS. EPIGENETIC CHANGES SUCH AS HISTONE MODIFICATIONS MAY MEDIATE CHRONIC INFLAMMATION AND ALSO FAVOR TUMOR CELLS IN IMMUNE RESISTANCE AND EVASION. THIS STUDY AIMED TO EVALUATE THE RELATIONSHIP BETWEEN HISTONE ACETYLATION (H3K9AC) AND DNA DAMAGE IN THE CONTEXT OF DYSPLASTIC LESIONS WITH PROMINENT CHRONIC INFLAMMATION. IMMUNOFLUORESCENCE OF "LOW-RISK" AND "HIGH-RISK" OPMD LESIONS (N = 24) AND INFLAMMATORY FIBROUS HYPERPLASIA (N = 10) AS THE CONTROL GROUP WAS PERFORMED TO ASSESS HISTONE ACETYLATION LEVELS AND DNA DAMAGE THROUGH THE PHOSPHORYLATION OF H2AX (GAMMAH2AX). CELL CO-CULTURE ASSAYS WITH PBMCS AND ORAL KERATINOCYTE CELL LINES (NOK-SI, DOK, AND SCC-25) WERE PERFORMED TO ASSESS PROLIFERATION, ADHESION, MIGRATION, AND EPITHELIAL-MESENCHYMAL TRANSITION (EMT). ORAL DYSPLASTIC LESIONS SHOWED A HYPOACETYLATION OF H3K9 AND LOW LEVELS OF GAMMAH2AX COMPARED TO CONTROL. THE CONTACT OF DYSPLASTIC ORAL KERATINOCYTES WITH PBMCS FAVORED EMT AND THE LOSS OF CELL-CELL ADHESION. ON THE OTHER HAND, P27 LEVELS INCREASED AND CYCLIN E DECREASED IN DOK, INDICATING CELL CYCLE ARREST. WE CONCLUDE THAT THE PRESENCE OF CHRONIC INFLAMMATION ASSOCIATED TO DYSPLASTIC LESIONS IS CAPABLE OF PROMOTING EPIGENETIC ALTERATIONS, WHICH IN TURN CAN FAVOR THE PROCESS OF MALIGNANT TRANSFORMATION. 2023 19 5688 30 SILENCING EFFECTS OF MUTANT RAS SIGNALLING ON TRANSCRIPTOMES. MUTATED GENES OF THE RAS FAMILY ENCODING SMALL GTP-BINDING PROTEINS DRIVE NUMEROUS CANCERS, INCLUDING PANCREATIC, COLON AND LUNG TUMORS. BESIDES THE NUMEROUS EFFECTS OF MUTANT RAS GENE EXPRESSION ON ABERRANT PROLIFERATION, TRANSFORMED PHENOTYPES, METABOLISM, AND THERAPY RESISTANCE, THE MOST STRIKING CONSEQUENCES OF CHRONIC RAS ACTIVATION ARE CHANGES OF THE GENETIC PROGRAM. BY PERFORMING SYSTEMATIC GENE EXPRESSION STUDIES IN CELLULAR MODELS THAT ALLOW COMPARISONS OF PRE-NEOPLASTIC WITH RAS-TRANSFORMED CELLS, WE AND OTHERS HAVE ESTIMATED THAT 7 PERCENT OR MORE OF ALL TRANSCRIPTS ARE ALTERED IN CONJUNCTION WITH THE EXPRESSION OF THE ONCOGENE. IN THIS CONTEXT, THE NUMBER OF UP-REGULATED TRANSCRIPTS APPROXIMATES THAT OF DOWN-REGULATED TRANSCRIPTS. WHILE UP-REGULATED TRANSCRIPTION FACTORS SUCH AS MYC, FOSL1, AND HMGA2 HAVE BEEN IDENTIFIED AND CHARACTERIZED AS RAS-RESPONSIVE DRIVERS OF THE ALTERED TRANSCRIPTOME, THE SUPPRESSED FACTORS HAVE BEEN LESS WELL STUDIED AS POTENTIAL REGULATORS OF THE GENETIC PROGRAM AND TRANSFORMED PHENOTYPE IN THE BREADTH OF THEIR OCCURRENCE. WE THEREFORE HAVE COLLECTED INFORMATION ON DOWNREGULATED RAS-RESPONSIVE FACTORS AND DISCUSS THEIR POTENTIAL ROLE AS TUMOR SUPPRESSORS THAT ARE LIKELY TO ANTAGONIZE ACTIVE CANCER DRIVERS. TO BETTER UNDERSTAND THE ACTIVE MECHANISMS THAT ENTAIL ANTI-RAS FUNCTION AND THOSE THAT LEAD TO LOSS OF TUMOR SUPPRESSOR ACTIVITY, WE FOCUS ON THE TUMOR SUPPRESSOR HREV107 (ALIAS PLAAT3 [PHOSPHOLIPASE A AND ACYLTRANSFERASE 3], PLA2G16 [PHOSPHOLIPASE A2, GROUP XVI] AND HRASLS3 [HRAS-LIKE SUPPRESSOR 3]). INACTIVATING HREV107 MUTATIONS IN TUMORS ARE EXTREMELY RARE, HENCE EPIGENETIC CAUSES MODULATED BY THE RAS PATHWAY ARE LIKELY TO LEAD TO DOWN-REGULATION AND LOSS OF FUNCTION. 2023 20 1584 26 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