1 1470 138 DISTINCT GENE EXPRESSION PROFILES IN IMMORTALIZED HUMAN UROTHELIAL CELLS EXPOSED TO INORGANIC ARSENITE AND ITS METHYLATED TRIVALENT METABOLITES. INORGANIC ARSENIC IS AN ENVIRONMENTAL CARCINOGEN. THE GENERATION OF TOXIC TRIVALENT METHYLATED METABOLITES COMPLICATES THE STUDY OF ARSENIC-MEDIATED CARCINOGENESIS. THIS STUDY SYSTEMATICALLY EVALUATED THE EFFECT OF CHRONIC TREATMENT WITH SODIUM ARSENITE (IAS(III)), MONOMETHYLARSONOUS ACID (MMA(III)), AND DIMETHYLARSINOUS ACID (DMA(III)) ON IMMORTALIZED HUMAN UROEPITHELIAL CELLS (SV-HUC-1 CELLS) USING CDNA MICROARRAY. AFTER EXPOSURE FOR 25 PASSAGES TO IAS(III) (0.5 MICROM), MMA(III) (0.05, 0.1, OR 0.2 MICROM), OR DMA(III) (0.2 OR 0.5 MICROM), SIGNIFICANT COMPOUND-SPECIFIC MORPHOLOGIC CHANGES WERE OBSERVED. A SET OF 114 GENES (5.7% OF THE EXAMINED GENES) WAS DIFFERENTIALLY EXPRESSED IN ONE OR MORE SETS OF ARSENICAL-TREATED CELLS COMPARED WITH UNTREATED CONTROLS. EXPRESSION ANALYSIS SHOWED THAT EXPOSURE OF CELLS TO DMA(III) RESULTED IN A GENE PROFILE DIFFERENT FROM THAT IN CELLS EXPOSED TO IAS(III) OR MMA(III), AND THAT THE IAS(III)-INDUCED GENE PROFILE WAS CLOSEST TO THAT IN THE TUMORIGENIC HUC-1-DERIVED 3-METHYLCHOLANTHRENE-INDUCED TUMORIGENIC CELL LINE MC-SV-HUC T2, WHICH WAS DERIVED FROM SV-HUC-1 CELLS BY METHYLCHOLANTHRENE TREATMENT. OF THE GENES AFFECTED BY ALL THREE ARSENICALS, ONLY ONE, THAT CODING FOR INTERLEUKIN-1 RECEPTOR, TYPE II, SHOWED ENHANCED EXPRESSION, A FINDING CONFIRMED BY THE REDUCED INCREASE IN NF-KAPPAB (NUCLEAR FACTOR KAPPA B) ACTIVITY SEEN IN RESPONSE TO INTERLEUKIN-1BETA IN IAS(III)-EXPOSED CELLS. THE EXPRESSION OF 11 GENES WAS SUPPRESSED BY ALL THREE ARSENICALS. 5-AZA-DEOXYCYTIDINE PARTIALLY RESTORED THE TRANSCRIPTION OF SEVERAL SUPPRESSED GENES, SHOWING THAT EPIGENETIC DNA METHYLATION WAS PROBABLY INVOLVED IN ARSENICAL-INDUCED GENE REPRESSION. OUR DATA DEMONSTRATE THAT CHRONIC EXPOSURE TO IAS(III), MMA(III), OR DMA(III) HAS DIFFERENT EPIGENETIC EFFECTS ON UROTHELIAL CELLS AND REPRESSES NF-KAPPAB ACTIVITY. 2006 2 977 43 CHRONIC ORAL EXPOSURE TO INORGANIC ARSENATE INTERFERES WITH METHYLATION STATUS OF P16INK4A AND RASSF1A AND INDUCES LUNG CANCER IN A/J MICE. ALTHOUGH INORGANIC ARSENATE (IAS(V)) OR ARSENITE (IAS(III)) IS CLEARLY A HUMAN CARCINOGEN, IT HAS BEEN DIFFICULT TO PRODUCE TUMORS IN RODENTS. IN THE PRESENT STUDY, WE ORALLY ADMINISTERED IAS(V) TO A/J MICE TO EXAMINE ARSENIC CARCINOGENICITY IN RODENT. A/J MICE (MALE, N = 120) ASSIGNED TO FOUR GROUPS WERE GIVEN DRINKING WATER CONTAINING 0, 1, 10, AND 100 PPM IAS(V) FOR 18 MONTHS. AT THE END OF EXPERIMENT, THE COMPLETE LUNGS WERE REMOVED AND USED FOR EXAMINING HISTOPATHOLOGY AND EXTRACTING RNA AND DNA. EPIGENETIC EFFECTS OF IAS(V) ON DNA METHYLATION PATTERNS OF P16INK4A AND RASSF1A GENES WERE DETERMINED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. CHANGES OF P16INK4A AND RASSF1A AT MRNA AND PROTEIN LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION AND IMMUNOHISTOCHEMISTRY. ARSENIC WAS ACCUMULATED DOSE DEPENDENTLY IN THE LUNG TISSUES OF IAS(V)-EXPOSED MICE. INCREASE IN LUNG TUMOR NUMBER AND LUNG TUMOR SIZE WAS OBSERVED IN IAS(V)-EXPOSED MICE COMPARED TO THE CONTROL. HISTOPATHOLOGICAL EXAMINATION SHOWED THAT THE RATE OF POORLY DIFFERENTIATED LUNG ADENOCARCINOMA WAS MUCH HIGHER IN IAS(V)-EXPOSED MICE THAN IN THE CONTROL. METHYLATION RATES APPEARED TO BE HIGHER IN A DOSE-RELATED TENDENCY IN LUNG TUMORS FROM IAS(V)-EXPOSED MICE COMPARED TO THE CONTROL. LOWER OR LOSS OF P16INK4A AND RASSF1A EXPRESSION WAS FOUND IN LUNG TUMORS FROM IAS(V)-EXPOSED MICE, COMPARED TO THAT IN NONTUMOR LUNG TISSUES FROM BOTH CONTROL AND IAS(V)-EXPOSED MICE, AND THIS REDUCED OR LOST EXPRESSION WAS IN ACCORDANCE WITH HYPERMETHYLATION OF THE GENES. IN CONCLUSION, IAS(V) EXPOSURE INCREASED LUNG TUMOR INCIDENCE AND MULTIPLICITY IN A/J MICE. EPIGENETIC CHANGES OF TUMOR SUPPRESSOR GENES SUCH AS P16INK4A AND RASSF1A ARE INVOLVED IN THE IAS(V)-INDUCED LUNG CARCINOGENESIS. 2006 3 473 35 ARSENIC AND URINARY BLADDER CELL PROLIFERATION. EPIDEMIOLOGIC STUDIES HAVE DEMONSTRATED THAT A CLOSE ASSOCIATION EXISTS BETWEEN THE ELEVATED LEVELS OF ARSENIC IN DRINKING WATER AND THE INCIDENCE OF CERTAIN CANCERS, INCLUDING TRANSITIONAL CELL CARCINOMAS OF THE URINARY BLADDER. WE HAVE EMPLOYED IN VITRO AND IN VIVO MODELS TO EXAMINE THE EFFECTS OF SODIUM ARSENITE ON THE URINARY BLADDER EPITHELIUM. MICE EXPOSED TO 0.01% SODIUM ARSENITE IN DRINKING WATER DEMONSTRATED HYPERPROLIFERATION OF THE BLADDER UROEPITHELIUM WITHIN 4 WEEKS AFTER INITIATING TREATMENT. THIS OCCURRED IN THE ABSENCE OF AMORPHOUS PRECIPITATES AND WAS ACCOMPANIED BY THE ACCUMULATION OF TRIVALENT ARSENITE (IAS(3+)), AND TO A LESSER EXTENT DIMETHYLARSENIC (DMA), ARSENATE (IAS(5+)), AND MONOMETHYLARSENIC (MMA) IN BLADDER TISSUE. IN CONTRAST TO THE BLADDER, URINARY SECRETION WAS PRIMARILY IN THE FORM OF DMA AND MMA. ARSENIC-INDUCED CELL PROLIFERATION IN THE BLADDER EPITHELIUM WAS CORRELATED WITH ACTIVATION OF THE MAP KINASE PATHWAY, LEADING TO EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK) KINASE ACTIVITY, AP-1 ACTIVATION, AND EXPRESSION OF AP-1-ASSOCIATED GENES INVOLVED IN CELL PROLIFERATION. ACTIVATION OF THE MAP KINASE PATHWAY INVOLVED BOTH EPIDERMAL GROWTH FACTOR (EGF) RECEPTOR-DEPENDENT AND -INDEPENDENT EVENTS, THE LATTER INVOLVING SRC ACTIVATION. STUDIES SUMMARIZED IN THIS REVIEW SUGGEST THAT ARSENIC ACCUMULATES IN URINARY BLADDER EPITHELIUM CAUSING ACTIVATION OF SPECIFIC SIGNALING PATHWAYS THAT LEAD TO CHRONIC INCREASED CELL PROLIFERATION. THIS MAY PLAY A NON-EPIGENETIC ROLE IN CARCINOGENESIS BY INCREASING THE PROLIFERATION OF INITIATED CELLS OR INCREASING THE MUTATIONAL RATE. 2004 4 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 5 1011 39 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 6 489 37 ASSESSING POTENTIAL MECHANISMS OF ARSENIC-INDUCED SKIN LESIONS AND CANCERS: HUMAN AND IN VITRO EVIDENCE. ENVIRONMENTAL EXPOSURE TO ARSENIC IS A MAJOR PUBLIC HEALTH CHALLENGE WORLDWIDE. IN DETAILING THE HALLMARK SIGNS OF CHRONIC ARSENIC EXPOSURE, PREVIOUS STUDIES HAVE SHOWN THAT EPIGENETIC AND IMMUNE DYSFUNCTION ARE ASSOCIATED WITH ARSENIC-INDUCED SKIN LESIONS; HOWEVER, KNOWLEDGE REGARDING INTERACTIONS BETWEEN THE MECHANISMS LISTED ABOVE IS LIMITED. IN THIS STUDY, A TOTAL OF 106 SKIN SAMPLES WERE COLLECTED OVER THE PAST 20 YEARS. BASED ON THE PRESENCE OR ABSENCE OF HIGH ARSENIC EXPOSURE, THE PARTICIPANTS WERE DIVIDED INTO ARSENIC EXPOSURE (72) AND REFERENCE (34) GROUPS. ADDITIONALLY, THE ARSENIC EXPOSURE GROUP WAS FURTHER DIVIDED INTO THE NON-CANCER GROUP (31, INCLUDING SKIN HYPERPIGMENTATION AND HYPERKERATOSIS) AND THE SKIN CANCER GROUP (41, INCLUDING BOWEN'S DISEASE, BASAL CELL CARCINOMA AND SQUAMOUS CELL CARCINOMA) ACCORDING TO A SKIN HISTOPATHOLOGICAL EXAMINATION. FIRST, THE ASSOCIATIONS AMONG MIR-155, NF-AT1 WITH IMMUNOLOGICAL DYSFUNCTION AND ARSENIC-INDUCED SKIN LESIONS AND CARCINOGENESIS WERE CONFIRMED USING THESE SKIN SAMPLES. IN THE ARSENIC-EXPOSED GROUP, MIR-155-5P, KERATIN 1(KRT1), KERATIN 10 (KRT10), AND KERATIN 6C (KRT6C) WERE SIGNIFICANTLY INCREASED IN THE SKIN (P < 0.05), WHILE NF-AT1, INTERLEUKIN-2 (IL-2), AND INTERFERON-GAMMA (IFN-GAMMA) WERE SIGNIFICANTLY DECREASED (P < 0.05). CLEAR CORRELATIONS WERE OBSERVED AMONG THESE FACTORS (P < 0.05). IN IMMORTALIZED HUMAN KERATINOCYTES, SILENCING AND OVEREXPRESSION OF NF-AT1 COULD ALTER THE EXPRESSION AND SECRETION OF IMMUNOLOGICAL DYSFUNCTION INDICATORS (IL-2 AND IFN-GAMMA) THAT ARE INDUCED BY ARSENIC EXPOSURE (P < 0.05); HOWEVER, MIR-155-5P LEVELS DID NOT CHANGE SIGNIFICANTLY (P > 0.05). THE MIR-155-5P MIMIC AND INHIBITOR COULD REGULATE THE NF-AT1-MEDIATED IMMUNOLOGICAL DYSFUNCTION CAUSED BY ARSENIC (P < 0.05). OUR STUDY PROVIDES SOME LIMITED EVIDENCE THAT MIR-155-5P REGULATES THE NF-AT1-MEDIATED IMMUNOLOGICAL DYSFUNCTION THAT IS INVOLVED IN THE PATHOGENESIS AND CARCINOGENESIS OF ARSENIC. THE SECOND MAJOR FINDING WAS THAT KRT1 AND KRT10 ARE MARKERS OF HYPERKERATOSIS CAUSED BY ARSENIC, AND KRT6C IS A POTENTIAL BIOMARKER THAT CAN REFLECT ARSENIC CARCINOGENESIS. 2020 7 2395 43 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 8 3468 39 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 9 1545 39 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 10 6794 33 [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 11 1966 37 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 12 1117 41 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 13 884 41 CHRONIC COEXPOSURE TO ARSENIC AND ESTROGEN POTENTIATES GENOTOXIC ESTROGEN METABOLIC PATHWAY AND HYPERMETHYLATION OF DNA GLYCOSYLASE MBD4 IN HUMAN PROSTATE EPITHELIAL CELLS. BACKGROUND: PREVIOUSLY WE REPORTED THAT ARSENIC AND ESTROGEN CAUSE SYNERGISTIC EFFECTS IN THE NEOPLASTIC TRANSFORMATION OF HUMAN PROSTATE EPITHELIAL CELLS. IN ADDITION TO RECEPTOR-MEDIATED PATHWAYS, DNA-REACTIVE ESTROGEN METABOLITES HAVE ALSO BEEN SHOWN TO PLAY A CRITICAL ROLE IN MUTAGENICITY AND CARCINOGENICITY. BOTH ESTROGEN AND ARSENIC ARE KNOWN PROSTATE CARCINOGENS, HOWEVER, THE EFFECT OF COEXPOSURE TO THESE TWO CHEMICALS ON GENES INVOLVED IN ESTROGEN METABOLISM IS NOT KNOWN. THEREFORE, THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE ROLE OF ARSENIC AND ESTROGEN COEXPOSURE ON THE EXPRESSION OF ESTROGEN RECEPTORS AND ESTROGEN METABOLISM-ASSOCIATED GENES. EARLIER, WE ALSO REPORTED THE SYNERGISTIC EFFECT OF ARSENIC AND ESTROGEN ON DECREASED EXPRESSION OF MBD4 GENES THAT PLAY AN IMPORTANT ROLE IN DNA REPAIR THROUGH ITS DNA GLYCOSYLASE ACTIVITY. TO FURTHER UNDERSTAND THE MECHANISM, THE PROMOTER METHYLATION OF THIS GENE WAS ALSO ANALYZED. METHODS: TOTAL RNA AND PROTEIN WERE ISOLATED FROM RWPE-1 HUMAN PROSTATE EPITHELIAL CELLS THAT WERE COEXPOSED TO ARSENIC AND ESTROGEN FOR A CHRONIC DURATION (6 MONTHS). THE EXPRESSION OF ESTROGEN RECEPTORS, ESTROGEN METABOLISM ASSOCIATED PHASE I GENES (CYP 1A1, 1A2, 3A4, AND 1B1) AND PHASE II GENE CATECHOL-O-METHYLTRANSFERASE (COMT), AS WELL AS ANTIOXIDANT MNSOD, WERE ANALYZED EITHER AT THE RNA LEVEL BY QUANTITATIVE REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION OR AT THE PROTEIN LEVEL BY WESTERN BLOT. PROMOTER METHYLATION OF MBD4 WAS ANALYZED BY PYROSEQUENCING. RESULTS: EXPRESSION OF MNSOD AND PHASE I GENES THAT CONVERT E(2) INTO GENOTOXIC METABOLITES 2-OH-E(2) AND 4-OH-E(2) WERE SIGNIFICANTLY INCREASED, WHEREAS THE EXPRESSION OF PHASE II GENE COMT THAT DETOXIFIES ESTROGEN METABOLITES WAS SIGNIFICANTLY DECREASED IN ARSENIC AND ESTROGEN COEXPOSED CELLS. MBD4 PROMOTER WAS HYPERMETHYLATED IN ARSENIC AND ESTROGEN COEXPOSED CELLS. COEXPOSURE TO ARSENIC AND ESTROGEN HAS SYNERGISTIC EFFECTS ON THE EXPRESSION OF THESE GENES AS WELL AS IN MBD4 PROMOTER HYPERMETHYLATION. CONCLUSIONS: THESE NOVEL FINDINGS SUGGEST THAT COEXPOSURE TO ARSENIC AND ESTROGEN ACTS SYNERGISTICALLY IN THE ACTIVATION OF NOT ONLY THE ESTROGEN RECEPTORS BUT ALSO THE GENES ASSOCIATED WITH GENOTOXIC ESTROGEN METABOLISM AND EPIGENETIC INACTIVATION OF DNA GLYCOSYLASE MBD4. TOGETHER, THESE GENETIC AND EPIGENETIC ABERRATIONS PROVIDE THE MOLECULAR BASIS FOR THE POTENTIATION OF CARCINOGENICITY OF ARSENIC AND ESTROGEN COEXPOSURE IN PROSTATE EPITHELIAL CELLS. 2022 14 1144 37 CONCOMITANT HETEROCHROMATINISATION AND DOWN-REGULATION OF GENE EXPRESSION UNVEILS EPIGENETIC SILENCING OF RELB IN AN AGGRESSIVE SUBSET OF CHRONIC LYMPHOCYTIC LEUKEMIA IN MALES. BACKGROUND: THE SENSITIVITY OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS TO CURRENT TREATMENTS, BOTH IN VITRO AND IN VIVO, RELIES ON THEIR ABILITY TO ACTIVATE APOPTOTIC DEATH. CLL CELLS RESISTANT TO DNA DAMAGE-INDUCED APOPTOSIS DISPLAY DEREGULATION OF A SPECIFIC SET OF GENES. METHODS: MICROARRAY HYBRIDIZATION (HUMAN GENECHIP, AFFYMETRIX), IMMUNOFLUORESCENT IN SITU LABELING COUPLED WITH VIDEO-MICROSCOPY RECORDING/ANALYSES, CHROMATIN-IMMUNOPRECIPITATION (CHIP), POLYMERASE CHAIN REACTIONS (PCR), REAL-TIME QUANTITATIVE PCR (RT-QPCR) AND BISULFITE GENOME SEQUENCING WERE THE MAIN METHODS APPLIED. STATISTICAL ANALYSES WERE PERFORMED BY APPLYING GCRMA AND SAM ANALYSIS (MICROARRAY DATA) AND STUDENT'S T-TEST OR MANN & WHITNEY'S U-TEST. RESULTS: HEREIN WE SHOW THAT, REMARKABLY, IN A RESISTANT MALE CLL CELLS THE VAST MAJORITY OF GENES WERE DOWN-REGULATED COMPARED WITH SENSITIVE CELLS, WHEREAS THIS WAS NOT THE CASE IN CELLS DERIVED FROM FEMALES. THIS GENE DOWN-REGULATION WAS FOUND TO BE ASSOCIATED WITH AN OVERALL GAIN OF HETEROCHROMATIN AS EVIDENCED BY IMMUNOFLUORESCENT LABELING OF HETEROCHROMATIN PROTEIN 1ALPHA (HP-1), TRIMETHYLATED HISTONE 3 LYSINE 9 (3METH3K9), AND 5-METHYLCYTIDINE (5METC). NOTABLY, 17 GENES WERE FOUND TO BE COMMONLY DEREGULATED IN RESISTANT MALE AND FEMALE CELL SAMPLES. AMONG THESE, RELB WAS IDENTIFIED AS A DISCRIMINATORY CANDIDATE GENE REPRESSED IN THE MALE AND UPREGULATED IN THE FEMALE RESISTANT CELLS. CONCLUSION: THE MOLECULAR DEFECTS IN THE SILENCING OF RELB INVOLVE AN INCREASE IN H3K9- BUT NOT CPG-ISLAND METHYLATION IN THE PROMOTER REGIONS. INCREASE IN ACETYL-H3 IN RESISTANT FEMALE BUT NOT MALE CLL SAMPLES AS WELL AS A DECREASE OF TOTAL CELLULAR LEVEL OF RELB AFTER AN INHIBITION OF HISTONE DEACETYLASE (HDAC) BY TRICHOSTATIN A (TSA), FURTHER EMPHASIZE THE ROLE OF EPIGENETIC MODIFICATIONS WHICH COULD DISCRIMINATE TWO CLL SUBSETS. TOGETHER, THESE RESULTS HIGHLIGHTED THE EPIGENETIC RELB SILENCING AS A NEW MARKER OF THE PROGRESSIVE DISEASE IN MALES. 2010 15 6411 37 THE SITE SPECIFIC DEMETHYLATION IN THE 5'-REGULATORY AREA OF NMDA RECEPTOR 2B SUBUNIT GENE ASSOCIATED WITH CIE-INDUCED UP-REGULATION OF TRANSCRIPTION. BACKGROUND: THE NMDA RECEPTOR REPRESENTS A PARTICULARLY IMPORTANT SITE OF ETHANOL ACTION IN THE CNS. WE RECENTLY REPORTED THAT NMDA RECEPTOR 2B (NR2B) GENE EXPRESSION WAS PERSISTENTLY UP-REGULATED FOLLOWING CHRONIC INTERMITTENT ETHANOL (CIE) TREATMENT. INCREASING EVIDENCE THAT EPIGENETIC MECHANISMS ARE INVOLVED IN DYNAMIC AND LONG-LASTING REGULATION OF GENE EXPRESSION IN MULTIPLE NEUROADAPTIVE PROCESSES PROMPTED US TO INVESTIGATE THE ROLE OF DNA METHYLATION IN MEDIATING CIE-INDUCED UP-REGULATION OF NR2B GENE TRANSCRIPTION. TO DISSECT THE CHANGES OF DNA METHYLATION IN THE NR2B GENE, WE HAVE SCREENED A LARGE NUMBER OF CPG SITES WITHIN ITS 5'-REGULATORY AREA FOLLOWING CIE TREATMENT. METHODS: PRIMARY CORTICAL CULTURED NEURONS WERE SUBJECTED TO ETHANOL TREATMENT IN A CIE PARADIGM. BISULFITE CONVERSION FOLLOWED BY PYROSEQUENCING WAS USED FOR QUANTITATIVE MEASUREMENT AND ANALYSIS OF CPG METHYLATION STATUS WITHIN THE 5'-REGULATORY AREA OF THE NR2B GENE; CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY WAS USED TO EXAMINE DNA LEVELS ASSOCIATED WITH METHYLATION AND TRANSCRIPTION FACTOR BINDING. ELECTROPHORETIC MOBILITY SHIFT ASSAY (EMSA) AND IN VITRO DNA METHYLATION ASSAYS WERE PERFORMED TO DETERMINE THE DIRECT IMPACT OF DNA METHYLATION ON THE INTERACTION BETWEEN DNA AND TRANSCRIPTION FACTOR AND PROMOTER ACTIVITY. RESULTS: ANALYSIS OF INDIVIDUAL CPG METHYLATION SITES WITHIN THE NR2B 5'REGULATORY AREA REVEALED THREE REGIONS WITH CLUSTERS OF SITE-SPECIFIC CPG DEMETHYLATION FOLLOWING CIE TREATMENT AND WITHDRAWAL. THIS WAS CONFIRMED BY CHIP SHOWING SIMILAR DECREASES OF METHYLATED DNA IN THE SAME REGIONS. THE CIE-INDUCED DEMETHYLATION IS CHARACTERIZED BY BEING LOCATED NEAR CERTAIN TRANSCRIPTION FACTOR BINDING SEQUENCES, AP-1 AND CRE, AND OCCURRED DURING TREATMENT AS WELL AS AFTER ETHANOL WITHDRAWAL. FURTHERMORE, THE INCREASE IN VITRO OF METHYLATED DNA DECREASED TRANSCRIPTION FACTOR BINDING ACTIVITY AND PROMOTER ACTIVITY. AN ADDITIONAL CHIP ASSAY INDICATED THAT THE CIE-INDUCED DNA DEMETHYLATION IS ACCOMPANIED BY INCREASED OCCUPATION BY TRANSCRIPTION FACTORS. CONCLUSIONS: THESE RESULTS SUGGEST AN IMPORTANT ROLE OF DNA DEMETHYLATION IN MEDIATING CIE-INDUCED NR2B GENE UP-REGULATION, THUS IMPLICATING A NOVEL MOLECULAR SITE OF ALCOHOL ACTION. 2010 16 5785 33 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 17 3658 38 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 18 6294 32 THE PROINFLAMMATORY CYTOKINE TNFALPHA INDUCES DNA DEMETHYLATION-DEPENDENT AND -INDEPENDENT ACTIVATION OF INTERLEUKIN-32 EXPRESSION. IL-32 IS A CYTOKINE INVOLVED IN PROINFLAMMATORY IMMUNE RESPONSES TO BACTERIAL AND VIRAL INFECTIONS. HOWEVER, THE ROLE OF EPIGENETIC EVENTS IN THE REGULATION OF IL-32 GENE EXPRESSION IS UNDERSTUDIED. HERE WE SHOW THAT IL-32 IS REPRESSED BY DNA METHYLATION IN HEK293 CELLS. USING CHIP SEQUENCING, LOCUS-SPECIFIC METHYLATION ANALYSIS, CRISPR/CAS9-MEDIATED GENOME EDITING, AND RT-QPCR (QUANTITATIVE RT-PCR) AND IMMUNOBLOT ASSAYS, WE FOUND THAT SHORT-TERM TREATMENT (A FEW HOURS) WITH THE PROINFLAMMATORY CYTOKINE TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) ACTIVATES IL-32 IN A DNA DEMETHYLATION-INDEPENDENT MANNER. IN CONTRAST, PROLONGED TNFALPHA TREATMENT (SEVERAL DAYS) INDUCED DNA DEMETHYLATION AT THE PROMOTER AND A CPG ISLAND IN THE IL-32 GENE IN A TET (TEN-ELEVEN TRANSLOCATION) FAMILY ENZYME- AND NF-KAPPAB-DEPENDENT MANNER. NOTABLY, THE HYPOMETHYLATION STATUS OF TRANSCRIPTIONAL REGULATORY ELEMENTS IN IL-32 WAS MAINTAINED FOR A LONG TIME (SEVERAL WEEKS), CAUSING ELEVATED IL-32 EXPRESSION EVEN IN THE ABSENCE OF TNFALPHA. CONSIDERING THAT IL-32 CAN, IN TURN, INDUCE TNFALPHA EXPRESSION, WE SPECULATE THAT SUCH FEEDFORWARD EVENTS MAY CONTRIBUTE TO THE TRANSITION FROM AN ACUTE INFLAMMATORY RESPONSE TO CHRONIC INFLAMMATION. 2019 19 155 24 ABERRANT METHYLATION OF POLO-LIKE KINASE CPG ISLANDS IN PLK4 HETEROZYGOUS MICE. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC), ONE OF THE MOST COMMON CANCERS WORLD-WIDE OCCURS TWICE AS OFTEN IN MEN COMPARED TO WOMEN. PREDISPOSING CONDITIONS SUCH AS ALCOHOLISM, CHRONIC VIRAL HEPATITIS, AFLATOXIN B1 INGESTION, AND CIRRHOSIS ALL CONTRIBUTE TO THE DEVELOPMENT OF HCC. METHODS: WE USED A COMBINATION OF METHYLATION SPECIFIC PCR AND BISULFITE SEQUENCING, QREAL-TIME PCR (QPCR), AND WESTERN BLOT ANALYSIS TO EXAMINE EPIGENETIC CHANGES FOR THE POLO-LIKE KINASES (PLKS) DURING THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC) IN PLK4 HETEROZYGOUS MICE AND MURINE EMBRYONIC FIBROBLASTS (MEFS). RESULTS: HERE WE REPORT THAT THE PROMOTER METHYLATION OF PLK4 CPG ISLANDS INCREASES WITH AGE, WAS MORE PREVALENT IN MALES AND THAT PLK4 EPIGENETIC MODIFICATION AND SUBSEQUENT DOWNREGULATION OF EXPRESSION WAS ASSOCIATED WITH THE DEVELOPMENT OF HCC IN PLK4 MUTANT MICE. INTERESTINGLY, THE OPPOSITE OCCURS WITH ANOTHER PLK FAMILY MEMBER, PLK1 WHICH WAS TYPICALLY HYPERMETHYLATED IN NORMAL LIVER TISSUE BUT BECAME HYPOMETHYLATED AND UPREGULATED IN LIVER TUMOURS. FURTHERMORE, UPON ALCOHOL EXPOSURE MURINE EMBRYONIC FIBROBLASTS EXHIBITED INCREASED PLK4 HYPERMETHYLATION AND DOWNREGULATION ALONG WITH INCREASED CENTROSOME NUMBERS AND MULTINUCLEATION. CONCLUSIONS: THESE RESULTS SUGGEST THAT ABERRANT PLK METHYLATION IS CORRELATED WITH THE DEVELOPMENT OF HCC IN MICE. 2011 20 4221 41 METHYLATION AND SILENCING OF PROTEIN TYROSINE PHOSPHATASE RECEPTOR TYPE O IN CHRONIC LYMPHOCYTIC LEUKEMIA. PURPOSE: PREVIOUS STUDIES IN OUR LABORATORY HAVE SHOWN THE PROGRESSIVE METHYLATION AND SUPPRESSION OF THE GENE ENCODING PROTEIN TYROSINE PHOSPHATASE, PTPRO, IN THE LIVERS OF RATS FED A METHYL-DEFICIENT DIET THAT INDUCES HEPATOCARCINOGENESIS. SUBSEQUENTLY, WE OBSERVED THE METHYLATION OF PTPRO IN PRIMARY HUMAN LUNG TUMORS AND ALSO SHOWED ITS POTENTIAL TUMOR SUPPRESSOR CHARACTERISTICS. THE PRESENT STUDY WAS UNDERTAKEN TO INVESTIGATE WHETHER THE TRUNCATED FORM OF PTPRO (PTPROT), SPECIFICALLY EXPRESSED IN NAIVE B LYMPHOCYTES, WAS ALSO METHYLATED AND SUPPRESSED IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), A DISEASE GENERALLY AFFECTING B LYMPHOCYTES. EXPERIMENTAL DESIGN AND RESULTS: INITIAL SCREENING SHOWED THAT 60% OF THE 52 CLL SAMPLES ANALYZED USING METHYLATION-SPECIFIC PCR ASSAY WERE METHYLATED COMPARED WITH B LYMPHOCYTES FROM NORMAL INDIVIDUALS, WHICH WERE NOT METHYLATED. THE EXPRESSION OF PTPROT, AS MEASURED BY SEMIQUANTITATIVE REVERSE TRANSCRIPTION-PCR, INVERSELY CORRELATED WITH METHYLATION IN THE FEW SAMPLES TESTED. ANALYSIS OF ADDITIONAL SAMPLES (N = 50) BY COMBINED BISULFITE RESTRICTION ANALYSIS SHOWED THAT THE PTPRO CPG ISLAND WAS METHYLATED IN 82% OF PATIENTS WITH CLL COMPARED WITH B LYMPHOCYTES FROM NORMAL INDIVIDUALS. FURTHERMORE, OVERALL EXPRESSION OF PTPRO WAS REDUCED IN CLL RELATIVE TO NORMAL LYMPHOCYTES. THE PTPRO GENE WAS ALSO SUPPRESSED BY METHYLATION IN THE CLL CELL LINE WAC3CD5, WHERE IT COULD BE REACTIVATED UPON TREATMENT WITH THE DNA HYPOMETHYLATING AGENT 5-AZAC. ECTOPIC EXPRESSION OF PTPROT IN A NONEXPRESSING CELL LINE INCREASED GROWTH INHIBITION WITH FLUDARABINE TREATMENT, A THERAPY COMMONLY USED FOR CLL. CONCLUSION: THIS STUDY REVEALS THE POTENTIAL ROLE OF PTPRO METHYLATION AND SILENCING IN CLL TUMORIGENESIS AND ALSO PROVIDES A NOVEL MOLECULAR TARGET IN THE EPIGENETIC THERAPY. 2007