1 6663 121 UPREGULATION OF HISTONE-LYSINE METHYLTRANSFERASES PLAYS A CAUSAL ROLE IN HEXAVALENT CHROMIUM-INDUCED CANCER STEM CELL-LIKE PROPERTY AND CELL TRANSFORMATION. WHILE HEXAVALENT CHROMIUM [CR(VI)] IS GENERALLY CONSIDERED AS A GENOTOXIC ENVIRONMENTAL CARCINOGEN, STUDIES SHOWED THAT CR(VI) EXPOSURE ALSO CAUSES EPIGENETIC CHANGES. HOWEVER, WHETHER CR(VI)-CAUSED EPIGENETIC DYSREGULATIONS PLAYS AN IMPORTANT ROLE IN CR(VI) CARCINOGENICITY REMAIN LARGELY UNKNOWN. THE AIM OF THIS STUDY WAS TO DETERMINE IF CHRONIC LOW DOSE CR(VI) EXPOSURE CAUSES EPIGENETIC CHANGES, THE UNDERLYING MECHANISM AND WHETHER CHRONIC LOW DOSE CR(VI) EXPOSURE-CAUSED EPIGENETIC DYSREGULATION CONTRIBUTES CAUSALLY TO CR(VI)-INDUCED CANCER STEM CELL (CSC)-LIKE PROPERTY AND CELL TRANSFORMATION. TWO IMMORTALIZED HUMAN BRONCHIAL EPITHELIAL CELL LINES (BEAS-2B AND 16HBE) WERE EXPOSED TO 0.25 MUM OF K(2)CR(2)O(7) FOR 20 AND 40 WEEKS TO INDUCE CELL TRANSFORMATION, RESPECTIVELY. CR(VI)-INDUCED EPIGENETIC CHANGES WERE EXAMINED IN CR(VI)-TRANSFORMED CELLS AND CR(VI) EXPOSURE-CAUSED HUMAN LUNG CANCER TISSUES. PHARMACOLOGICAL INHIBITORS AND GENE KNOCKDOWN EXPERIMENTS WERE USED TO DETERMINE THE ROLE OF EPIGENETIC DYSREGULATION IN CR(VI) CARCINOGENICITY. WE FOUND THAT CHRONIC CR(VI) EXPOSURE CAUSES EPIGENETIC DYSREGULATION AS EVIDENCED BY THE INCREASED LEVELS OF HISTONE H3 REPRESSIVE METHYLATION MARKS (H3K9ME2 AND H3K27ME3) AND THE RELATED HISTONE-LYSING METHYLTRANSFERASES (HMTASES). PHARMACOLOGICAL INHIBITION OR KNOCKDOWN OF HMTASES REDUCES H3 REPRESSIVE METHYLATION MARKS AND MALIGNANT PHENOTYPES OF CR(VI)-TRANSFORMED CELLS. MOREOVER, KNOCKDOWN OF HMTASES IN PARENTAL CELLS SIGNIFICANTLY REDUCES CHRONIC CR(VI) EXPOSURE-INDUCED CSC-LIKE PROPERTY AND CELL TRANSFORMATION. FURTHER MECHANISTIC STUDY REVEALED THAT KNOCKDOWN OF HMTASES DECREASES CR(VI) EXPOSURE-CAUSED DNA DAMAGE. OUR FINDINGS INDICATE THAT CHRONIC CR(VI) EXPOSURE INCREASES H3 REPRESSIVE METHYLATION MARKS BY INCREASING THE RELATED HMTASES EXPRESSION; AND THAT INCREASED EXPRESSION OF HMTASES PLAYS A CAUSAL ROLE IN CR(VI)-INDUCED CSC-LIKE PROPERTY AND CELL TRANSFORMATION. 2018 2 1987 46 EPIGENETIC ALTERATIONS OF CXCL5 IN CR(VI)-INDUCED CARCINOGENESIS. CHRONIC EXPOSURE TO HEXAVALENT CHROMIUM COMPOUNDS [CR(VI)] IS ASSOCIATED WITH AN INCREASED RISK OF CANCERS, BUT THE MOLECULAR MECHANISMS REMAIN TO BE ELUCIDATED. IN THIS STUDY, WE FOUND THAT CXCL5 LEVELS IN PERIPHERAL BLOOD MONOCYTES (PBMCS) AND PLASMA FROM WORKERS WITH OCCUPATIONAL EXPOSURE TO CR(VI) WERE DRAMATICALLY UPREGULATED COMPARED TO NON-EXPOSURE HEALTHY SUBJECTS, AND PLASMA C-X-C MOTIF CHEMOKINE LIGAND 5 (CXCL5) CXCL5 LEVELS WERE POSITIVELY CORRELATED WITH CR CONCENTRATIONS IN SUBJECTS' TOENAILS. ZINC CHROMATE EXPOSED MICE SHOWED HIGHER LEVELS OF CXCL5 AND ITS RECEPTOR CXCR2 IN LUNG TISSUES, AND IN PBMCS. SIMILAR CXCL5 UPREGULATION WAS EVIDENT IN CR(VI)-INDUCED TRANSFORMED (CR-T) CELLS WITH LONG-TERM CR(VI) TREATMENT. MECHANISTIC STUDIES SHOWED THAT ELEVATED CXCL5 EXPRESSION LEVELS WERE REGULATED BY CR(VI)-INDUCED HISTONE MODIFICATIONS AND DNA HYPOMETHYLATION, AND THAT THE C-MYC/P300 COMPLEX WAS A KEY UPSTREAM REGULATOR OF HISTONE H3 ACETYLATION. CXCL5 OVEREXPRESSION PROMOTED CR(VI)-INDUCED THE EPITHELIAL TO MESENCHYME TRANSITION (EMT) BY UPREGULATING ZINC FINGER E-BOX BINDING HOMEOBOX 1 (ZEB1) TO PROMOTE TUMOR DEVELOPMENT. OUR FINDINGS IDENTIFY A NOVEL MECHANISM BY WHICH CXCL5 IS UPREGULATED AND PROMOTES EMT AND CARCINOGENESIS UPON CHRONIC CR(VI) EXPOSURE. OUR WORK ALSO IMPLIES THAT CXCL5 MRNA AND PROTEIN LEVELS WILL ELEVATE IN PBMCS AND SERUM AFTER OCCUPATIONAL CR(VI) EXPOSURE, WHICH MAY BE A POTENTIAL TARGET AND BIOMARKER FOR CANCER PREVENTION AND HEALTH SURVEILLANCE AMONG POPULATIONS EXPOSED TO CR(VI). 2022 3 1557 29 DNA METHYLATION MODIFICATIONS INDUCED BY HEXAVALENT CHROMIUM. HEXAVALENT CHROMIUM [CR (VI)] CONTRIBUTES A SIGNIFICANT HEALTH RISK AND CAUSES A NUMBER OF CHRONIC DISEASES AND CANCERS. WHILE THE GENOTOXIC AND CARCINOGENIC EFFECTS OF HEXAVALENT CHROMIUM EXPOSURE ARE EXPLICIT AND BETTER-CHARACTERIZED, THE EXACT MECHANISM UNDERLYING THE CARCINOGENIC PROCESS OF CR (VI) IS STILL A MATTER OF DEBATE. IN RECENT YEARS, STUDIES HAVE SHOWN THAT EPIGENETIC MODIFICATIONS, ESPECIALLY DNA METHYLATION, MAY PLAY A SIGNIFICANT ROLE IN CR (VI)-INDUCED CARCINOGENESIS. THE AIM OF THIS REVIEW IS TO SUMMARIZE OUR UNDERSTANDING REGARDING THE EFFECTS OF CR (VI) ON GLOBAL AND GENE-SPECIFIC DNA METHYLATION. 2019 4 3942 52 LNCRNA DUXAP10 UPREGULATION AND THE HEDGEHOG PATHWAY ACTIVATION ARE CRITICALLY INVOLVED IN CHRONIC CADMIUM EXPOSURE-INDUCED CANCER STEM CELL-LIKE PROPERTY. CADMIUM (CD) IS A WELL-KNOWN LUNG CARCINOGEN. HOWEVER, THE MECHANISM OF CD CARCINOGENESIS REMAINS TO BE CLEARLY DEFINED. CD HAS BEEN SHOWN TO ACT AS A WEAK MUTAGEN, SUGGESTING THAT IT MAY EXERT TUMORIGENIC EFFECT THROUGH NONGENOTOXIC WAYS, SUCH AS EPIGENETIC MECHANISMS. LONG NONCODING RNAS (LNCRNAS) REFER TO RNA MOLECULES THAT ARE LONGER THAN 200 NUCLEOTIDES IN LENGTH BUT LACK PROTEIN-CODING CAPACITIES. REGULATION OF GENE EXPRESSIONS BY LNCRNAS IS CONSIDERED AS ONE OF IMPORTANT EPIGENETIC MECHANISMS. THE GOAL OF THIS STUDY IS TO INVESTIGATE THE MECHANISM OF CD CARCINOGENESIS FOCUSING ON THE ROLE OF LNCRNA DYSREGULATIONS. CD-INDUCED MALIGNANT TRANSFORMATION OF HUMAN BRONCHIAL EPITHELIA BEAS-2B CELLS WAS ACCOMPLISHED BY A 9-MONTH LOW-DOSE CD (CDCL2, 2.5 MICROM) EXPOSURE. THE CD-EXPOSED CELLS FORMED SIGNIFICANTLY MORE COLONIES IN SOFT AGAR, DISPLAYED CANCER STEM CELL (CSC)-LIKE PROPERTY, AND FORMED TUMORS IN NUDE MICE. MECHANISTICALLY, CHRONIC LOW-DOSE CD EXPOSURE DID NOT CAUSE SIGNIFICANT GENOTOXIC EFFECTS BUT DYSREGULATED LNCRNA EXPRESSIONS. FURTHER Q-PCR ANALYSIS CONFIRMED THE SIGNIFICANT UPREGULATION OF THE ONCOGENIC LNCRNA DUXAP10 IN CD-TRANSFORMED CELLS. DUXAP10 KNOCKDOWN IN CD-TRANSFORMED CELLS SIGNIFICANTLY REDUCED THEIR CSC-LIKE PROPERTY. FURTHER MECHANISTIC STUDIES SHOWED THAT THE HEDGEHOG PATHWAY IS ACTIVATED IN CD-TRANSFORMED CELLS AND INHIBITION OF THIS PATHWAY REDUCES CD-INDUCED CSC-LIKE PROPERTY. DUXAP10 KNOCKDOWN CAUSED THE HEDGEHOG PATHWAY INACTIVATION IN CD-TRANSFORMED CELLS. FURTHERMORE, PAX6 EXPRESSION WAS UPREGULATED IN CD-TRANSFORMED CELLS AND PAX6 KNOCKDOWN SIGNIFICANTLY REDUCED THEIR DUXAP10 LEVELS AND CSC-LIKE PROPERTY. IN SUMMARY, THESE FINDINGS SUGGEST THAT THE LNCRNA DUXAP10 UPREGULATION MAY PLAY AN IMPORTANT ROLE IN CD CARCINOGENESIS. 2021 5 1122 50 COMPARISON OF GENE EXPRESSION PROFILES IN CHROMATE TRANSFORMED BEAS-2B CELLS. BACKGROUND: HEXAVALENT CHROMIUM [CR(VI)] IS A POTENT HUMAN CARCINOGEN. OCCUPATIONAL EXPOSURE HAS BEEN ASSOCIATED WITH INCREASED RISK OF RESPIRATORY CANCER. MULTIPLE MECHANISMS HAVE BEEN SHOWN TO CONTRIBUTE TO CR(VI) INDUCED CARCINOGENESIS, INCLUDING DNA DAMAGE, GENOMIC INSTABILITY, AND EPIGENETIC MODULATION, HOWEVER, THE MOLECULAR MECHANISM AND DOWNSTREAM GENES MEDIATING CHROMIUM'S CARCINOGENICITY REMAIN TO BE ELUCIDATED. METHODS/RESULTS: WE ESTABLISHED CHROMATE TRANSFORMED CELL LINES BY CHRONIC EXPOSURE OF NORMAL HUMAN BRONCHIAL EPITHELIAL BEAS-2B CELLS TO LOW DOSES OF CR(VI) FOLLOWED BY ANCHORAGE-INDEPENDENT GROWTH. THESE TRANSFORMED CELL LINES NOT ONLY EXHIBITED CONSISTENT MORPHOLOGICAL CHANGES BUT ALSO ACQUIRED ALTERED AND DISTINCT GENE EXPRESSION PATTERNS COMPARED WITH NORMAL BEAS-2B CELLS AND CONTROL CELL LINES (UNTREATED) THAT AROSE SPONTANEOUSLY IN SOFT AGAR. INTERESTINGLY, THE GENE EXPRESSION PROFILES OF SIX CR(VI) TRANSFORMED CELL LINES WERE REMARKABLY SIMILAR TO EACH OTHER YET DIFFERED SIGNIFICANTLY FROM THAT OF EITHER CONTROL CELL LINES OR NORMAL BEAS-2B CELLS. A TOTAL OF 409 DIFFERENTIALLY EXPRESSED GENES WERE IDENTIFIED IN CR(VI) TRANSFORMED CELLS COMPARED TO CONTROL CELLS. GENES RELATED TO CELL-TO-CELL JUNCTION WERE UPREGULATED IN ALL CR(VI) TRANSFORMED CELLS, WHILE GENES ASSOCIATED WITH THE INTERACTION BETWEEN CELLS AND THEIR EXTRACELLULAR MATRICES WERE DOWN-REGULATED. ADDITIONALLY, EXPRESSION OF GENES INVOLVED IN CELL PROLIFERATION AND APOPTOSIS WERE ALSO CHANGED. CONCLUSION: THIS STUDY IS THE FIRST TO REPORT GENE EXPRESSION PROFILING OF CR(VI) TRANSFORMED CELLS. THE GENE EXPRESSION CHANGES ACROSS INDIVIDUAL CHROMATE EXPOSED CLONES WERE REMARKABLY SIMILAR TO EACH OTHER BUT DIFFERED SIGNIFICANTLY FROM THE GENE EXPRESSION FOUND IN ANCHORAGE-INDEPENDENT CLONES THAT AROSE SPONTANEOUSLY. OUR ANALYSIS IDENTIFIED MANY NOVEL GENE EXPRESSION CHANGES THAT MAY CONTRIBUTE TO CHROMATE INDUCED CELL TRANSFORMATION, AND COLLECTIVELY THIS TYPE OF INFORMATION WILL PROVIDE A BETTER UNDERSTANDING OF THE MECHANISM UNDERLYING CHROMATE CARCINOGENICITY. 2011 6 1993 44 EPIGENETIC AND EPITRANSCRIPTOMIC MECHANISMS OF CHROMIUM CARCINOGENESIS. HEXAVALENT CHROMIUM [CR(VI)], A GROUP I CARCINOGEN CLASSIFIED BY THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER (IARC), REPRESENTS ONE OF THE MOST COMMON OCCUPATIONAL AND ENVIRONMENTAL POLLUTANTS. THE FINDINGS FROM HUMAN EPIDEMIOLOGICAL AND LABORATORY ANIMAL STUDIES SHOW THAT LONG-TERM EXPOSURE TO CR(VI) CAUSES LUNG CANCER AND OTHER CANCER. ALTHOUGH CR(VI) IS A WELL-RECOGNIZED CARCINOGEN, THE MECHANISM OF CR(VI) CARCINOGENESIS HAS NOT BEEN WELL UNDERSTOOD. DUE TO THE FACT THAT CR(VI) UNDERGOES A SERIES OF METABOLIC REDUCTIONS ONCE ENTERING CELLS TO GENERATE REACTIVE CR METABOLITES AND REACTIVE OXYGEN SPECIES (ROS) CAUSING GENOTOXICITY, CR(VI) IS GENERALLY CONSIDERED AS A GENOTOXIC CARCINOGEN. HOWEVER, MORE AND MORE STUDIES HAVE DEMONSTRATED THAT ACUTE OR CHRONIC CR(VI) EXPOSURE ALSO CAUSES EPIGENETIC DYSREGULATIONS INCLUDING CHANGING DNA METHYLATION, HISTONE POSTTRANSLATIONAL MODIFICATIONS AND REGULATORY NON-CODING RNA (MICRORNA AND LONG NON-CODING RNA) EXPRESSIONS. MOREOVER, EMERGING EVIDENCE SHOWS THAT CR(VI) EXPOSURE IS ALSO CAPABLE OF ALTERING CELLULAR EPITRANSCRIPTOME. GIVEN THE INCREASINGLY RECOGNIZED IMPORTANCE OF EPIGENETIC AND EPITRANSCRIPTOMIC DYSREGULATIONS IN CANCER INITIATION AND PROGRESSION, IT IS BELIEVED THAT CR(VI) EXPOSURE-CAUSED EPIGENETIC AND EPITRANSCRIPTOMIC CHANGES COULD PLAY IMPORTANT ROLES IN CR(VI) CARCINOGENESIS. THE GOAL OF THIS CHAPTER IS TO REVIEW THE EPIGENETIC AND EPITRANSCRIPTOMIC EFFECTS OF CR(VI) EXPOSURE AND DISCUSS THEIR ROLES IN CR(VI) CARCINOGENESIS. BETTER UNDERSTANDING THE MECHANISM OF CR(VI) CARCINOGENESIS MAY IDENTIFY NEW MOLECULAR TARGETS FOR MORE EFFICIENT PREVENTION AND TREATMENT OF CANCER RESULTING FROM CR(VI) EXPOSURE. 2023 7 3658 39 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 8 323 39 ALKBH4 STABILIZATION IS REQUIRED FOR ARSENIC-INDUCED 6MA DNA METHYLATION INHIBITION, KERATINOCYTE MALIGNANT TRANSFORMATION, AND TUMORIGENICITY. INORGANIC ARSENIC IS ONE OF THE WELL-KNOWN HUMAN SKIN CARCINOGENS. HOWEVER, THE MOLECULAR MECHANISM BY WHICH ARSENIC PROMOTES CARCINOGENESIS REMAINS UNCLEAR. PREVIOUS STUDIES HAVE ESTABLISHED THAT EPIGENETIC CHANGES, INCLUDING CHANGES IN DNA METHYLATION, ARE AMONG THE CRITICAL MECHANISMS THAT DRIVE CARCINOGENESIS. N(6)-METHYLADENINE (6MA) METHYLATION ON DNA IS A WIDESPREAD EPIGENETIC MODIFICATION THAT WAS INITIALLY FOUND ON BACTERIAL AND PHAGE DNA. ONLY RECENTLY HAS 6MA BEEN IDENTIFIED IN MAMMALIAN GENOMES. HOWEVER, THE FUNCTION OF 6MA IN GENE EXPRESSION AND CANCER DEVELOPMENT IS NOT WELL UNDERSTOOD. HERE, WE SHOW THAT CHRONIC LOW DOSES OF ARSENIC INDUCE MALIGNANT TRANSFORMATION AND TUMORIGENESIS IN KERATINOCYTES AND LEAD TO THE UPREGULATION OF ALKBH4 AND DOWNREGULATION OF 6MA ON DNA. WE FOUND THAT REDUCED 6MA LEVELS IN RESPONSE TO LOW LEVELS OF ARSENIC WERE MEDIATED BY THE UPREGULATION OF THE 6MA DNA DEMETHYLASE ALKBH4. MOREOVER, WE FOUND THAT ARSENIC INCREASED ALKBH4 PROTEIN LEVELS AND THAT ALKBH4 DELETION IMPAIRED ARSENIC-INDUCED TUMORIGENICITY IN VITRO AND IN MICE. MECHANISTICALLY, WE FOUND THAT ARSENIC PROMOTED ALKBH4 PROTEIN STABILITY THROUGH REDUCED AUTOPHAGY. TOGETHER, OUR FINDINGS REVEAL THAT THE DNA 6MA DEMETHYLASEALKBH4 PROMOTES ARSENIC TUMORIGENICITY AND ESTABLISHES ALKBH4 AS A PROMISING TARGET FOR ARSENIC-INDUCED TUMORIGENESIS. 2022 9 1011 33 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 10 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 11 5972 33 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 12 979 37 CHRONIC OXIDATIVE STRESS INCREASES RESISTANCE TO DOXORUBICIN-INDUCED CYTOTOXICITY IN RENAL CARCINOMA CELLS POTENTIALLY THROUGH EPIGENETIC MECHANISM. RENAL CELL CARCINOMA IS THE MOST COMMON FORM OF KIDNEY CANCER AND IS HIGHLY RESISTANT TO CHEMOTHERAPY. ALTHOUGH THE ROLE OF OXIDATIVE STRESS IN KIDNEY CANCER IS KNOWN, THE CHEMOTHERAPEUTIC RESPONSE OF CANCER CELLS ADAPTED TO CHRONIC OXIDATIVE STRESS IS NOT CLEAR. HENCE, THE EFFECT OF OXIDATIVE STRESS ON SENSITIVITY TO DOXORUBICIN-INDUCED CYTOTOXICITY WAS EVALUATED USING AN IN VITRO MODEL OF HUMAN KIDNEY CANCER CELLS ADAPTED TO CHRONIC OXIDATIVE STRESS. RESULTS OF MTT- AND ANCHORAGE-INDEPENDENT GROWTH ASSAYS AND CELL CYCLE ANALYSIS REVEALED SIGNIFICANT DECREASE IN SENSITIVITY TO DOXORUBICIN IN CAKI-1 CELLS ADAPTED TO OXIDATIVE STRESS. CHANGES IN THE EXPRESSION OF GENES INVOLVED IN DRUG TRANSPORT, CELL SURVIVAL, AND DNA REPAIR-DEPENDENT APOPTOSIS FURTHER CONFIRMED INCREASED RESISTANCE TO DOXORUBICIN-INDUCED CYTOTOXICITY IN THESE CELLS. DECREASED EXPRESSION OF MISMATCH REPAIR (MMR) GENE MSH2 IN CELLS EXPOSED TO OXIDATIVE STRESS SUGGESTS THAT LOSS OF MMR-DEPENDENT APOPTOSIS COULD BE A POTENTIAL MECHANISM FOR INCREASED RESISTANCE TO DOXORUBICIN-INDUCED CYTOTOXICITY. ADDITIONALLY, DOWNREGULATION OF HDAC1, AN INCREASE IN THE LEVEL OF HISTONE H3 ACETYLATION, AND HYPERMETHYLATION OF MSH2 PROMOTER WERE ALSO OBSERVED IN CAKI-1 CELLS ADAPTED TO CHRONIC OXIDATIVE STRESS. DNA-DEMETHYLATING AGENT 5-AZA-2DC SIGNIFICANTLY RESTORED THE EXPRESSION OF MSH2 AND DOXORUBICIN-INDUCED CYTOTOXICITY IN CAKI-1 CELLS ADAPTED TO CHRONIC OXIDATIVE STRESS, SUGGESTING THE ROLE OF DNA HYPERMETHYLATION IN INACTIVATION OF MSH2 EXPRESSION AND CONSEQUENTLY MMR-DEPENDENT APOPTOSIS IN THESE CELLS. IN SUMMARY, THIS STUDY FOR THE FIRST TIME PROVIDES DIRECT EVIDENCE FOR THE ROLE OF OXIDATIVE STRESS IN CHEMOTHERAPEUTIC RESISTANCE IN RENAL CARCINOMA CELLS POTENTIALLY THROUGH EPIGENETIC MECHANISM. 2016 13 1615 30 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 3468 44 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 15 2395 34 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 16 1117 32 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 17 473 24 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 18 164 34 ABNORMAL HISTONE METHYLATION IS RESPONSIBLE FOR INCREASED VASCULAR ENDOTHELIAL GROWTH FACTOR 165A SECRETION FROM AIRWAY SMOOTH MUSCLE CELLS IN ASTHMA. VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF), A KEY ANGIOGENIC MOLECULE, IS ABERRANTLY EXPRESSED IN SEVERAL DISEASES INCLUDING ASTHMA WHERE IT CONTRIBUTES TO BRONCHIAL VASCULAR REMODELING AND CHRONIC INFLAMMATION. ASTHMATIC HUMAN AIRWAY SMOOTH MUSCLE CELLS HYPERSECRETE VEGF, BUT THE MECHANISM IS UNCLEAR. IN THIS STUDY, WE DEFINED THE MECHANISM IN HUMAN AIRWAY SMOOTH MUSCLE CELLS FROM NONASTHMATIC AND ASTHMATIC PATIENTS. WE FOUND THAT ASTHMATIC CELLS LACKED A REPRESSION COMPLEX AT THE VEGF PROMOTER, WHICH WAS PRESENT IN NONASTHMATIC CELLS. RECRUITMENT OF G9A, TRIMETHYLATION OF HISTONE H3 AT LYSINE 9 (H3K9ME3), AND A RESULTANT DECREASE IN RNA POLYMERASE II AT THE VEGF PROMOTER WAS CRITICAL TO REPRESSION OF VEGF SECRETION IN NONASTHMATIC CELLS. AT THE ASTHMATIC PROMOTER, H3K9ME3 WAS ABSENT BECAUSE OF FAILED RECRUITMENT OF G9A; RNA POLYMERASE II BINDING, IN ASSOCIATION WITH TATA-BINDING PROTEIN-ASSOCIATED FACTOR 1, WAS INCREASED; H3K4ME3 WAS PRESENT; AND SP1 BINDING WAS EXAGGERATED AND SUSTAINED. IN CONTRAST, DNA METHYLATION AND HISTONE ACETYLATION WERE SIMILAR IN ASTHMATIC AND NONASTHMATIC CELLS. THIS IS THE FIRST STUDY, TO OUR KNOWLEDGE, TO SHOW THAT AIRWAY CELLS IN ASTHMA HAVE ALTERED EPIGENETIC REGULATION OF REMODELING GENE(S). HISTONE METHYLATION AT GENES SUCH AS VEGF MAY BE AN IMPORTANT NEW THERAPEUTIC TARGET. 2012 19 2926 32 GENERATION OF AN EPIGENETIC SIGNATURE BY CHRONIC HYPOXIA IN PROSTATE CELLS. INCREASING LEVELS OF TISSUE HYPOXIA HAVE BEEN REPORTED AS A NATURAL FEATURE OF THE AGING PROSTATE GLAND AND MAY BE A RISK FACTOR FOR THE DEVELOPMENT OF PROSTATE CANCER. IN THIS STUDY, WE HAVE USED PWR-1E BENIGN PROSTATE EPITHELIAL CELLS AND AN EQUIVALENTLY AGED HYPOXIA-ADAPTED PWR-1E SUB-LINE TO IDENTIFY PHENOTYPIC AND EPIGENETIC CONSEQUENCES OF CHRONIC HYPOXIA IN PROSTATE CELLS. WE HAVE IDENTIFIED A SIGNIFICANTLY ALTERED CELLULAR PHENOTYPE IN RESPONSE TO CHRONIC HYPOXIA AS CHARACTERIZED BY INCREASED RECEPTOR-MEDIATED APOPTOTIC RESISTANCE, THE INDUCTION OF CELLULAR SENESCENCE, INCREASED INVASION AND THE INCREASED SECRETION OF IL-1 BETA, IL6, IL8 AND TNFALPHA CYTOKINES. IN ASSOCIATION WITH THESE PHENOTYPIC CHANGES AND THE ABSENCE OF HIF-1 ALPHA PROTEIN EXPRESSION, WE HAVE DEMONSTRATED SIGNIFICANT INCREASES IN GLOBAL LEVELS OF DNA METHYLATION AND H3K9 HISTONE ACETYLATION IN THESE CELLS, CONCOMITANT WITH THE INCREASED EXPRESSION OF DNA METHYLTRANSFERASE DMNT3B AND GENE-SPECIFIC CHANGES IN DNA METHYLATION AT KEY IMPRINTING LOCI. IN CONCLUSION, WE HAVE DEMONSTRATED A GENOME-WIDE ADJUSTMENT OF DNA METHYLATION AND HISTONE ACETYLATION UNDER CHRONIC HYPOXIC CONDITIONS IN THE PROSTATE. THESE EPIGENETIC SIGNATURES MAY REPRESENT AN ADDITIONAL MECHANISM TO PROMOTE AND MAINTAIN A HYPOXIC-ADAPTED CELLULAR PHENOTYPE WITH A POTENTIAL ROLE IN TUMOUR DEVELOPMENT. 2009 20 2673 45 ETHANOL-INDUCED MODULATION OF GPR55 EXPRESSION IN HUMAN MONOCYTE-DERIVED DENDRITIC CELLS IS ACCOMPANIED BY H4K12 ACETYLATION. INFLAMMATION SUPPORTS THE PROGRESSION OF ALCOHOL-RELATED ORGAN INJURY. RECENT RESEARCH FINDINGS HAVE LINKED ETHANOL EXPOSURE TO CHANGES IN HISTONE ACETYLATION AND DEACETYLATION IN THE BRAIN AND IN PERIPHERAL TISSUES, LEADING TO ETHANOL-DEPENDENCE RELATED DAMAGE. ONE OF THE MECHANISMS THAT HAS BEEN SHOWN TO PLAY A MAJOR ROLE DURING INFLAMMATION IS THE CANNABINOID SYSTEM. PREVIOUS RESEARCH HAS DEMONSTRATED THAT ETHANOL CAN MODULATE CANNABINOID RECEPTORS' FUNCTIONS. OUR LAB HAS SHOWN THAT THE G PROTEIN-COUPLED RECEPTOR (GPR55), A NOVEL CANNABINOID RECEPTOR, IS UPREGULATED IN BINGE DRINKERS AND IN CELLS TREATED ACUTELY WITH ETHANOL. ADDITIONALLY, OUR GROUP HAS ALSO UNCOVERED THAT CHRONIC ETHANOL EXPOSURE LEADS TO AN INCREASE IN HISTONE MODIFICATIONS, SUCH AS ACETYLATION. HOWEVER, THE REGULATORY MECHANISM OF GPR55 WITHIN THE IMMUNE SYSTEM UNDER THE INFLUENCE OF ETHANOL IS POORLY UNDERSTOOD. SINCE CHANGES IN HISTONE MODIFICATIONS MIGHT LEAD TO CHANGES IN GENE EXPRESSION, WE HYPOTHESIZE THAT THE MECHANISM OF ETHANOL-INDUCED UPREGULATION OF GPR55 IS LINKED TO EPIGENETIC CHANGES ON HISTONE PROTEINS. TAKING INTO ACCOUNT PREVIOUS FINDINGS FROM OUR LAB, THE GOAL OF THE PRESENT STUDY WAS TO DETERMINE WHETHER THERE IS ANY RELEVANT ASSOCIATION BETWEEN HISTONE HYPERACETYLATION AND THE REGULATION OF THE NOVEL CANNABINOID RECEPTOR GPR55 IN MONOCYTE-DERIVED DENDRITIC CELLS (MDDCS) OF HUMAN ORIGIN TREATED ACUTELY WITH ETHANOL. THEREFORE, MONOCYTES WERE ISOLATED FROM BUFFY COATS AND ALLOWED TO DIFFERENTIATE INTO MDDCS. THE CELLS WERE TREATED WITH ETHANOL FOR 24 H, HARVESTED, FIXED, AND STAINED WITH ANTIBODIES AGAINST GPR55. AS EXPECTED, BASED ON PREVIOUS FINDINGS, CONFOCAL MICROSCOPY SHOWED THAT ETHANOL EXPOSURE INCREASES GPR55 EXPRESSION. IN ORDER TO DEMONSTRATE THE CORRELATION BETWEEN HISTONE ACETYLATION AND GPR55 EXPRESSION REGULATION, THE CELLS WERE TREATED WITH ETHANOL, HARVESTED, AND THEN THE CHROMATIN WAS EXTRACTED AND FRACTIONATED FOR CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY, FOLLOWED BY REAL-TIME QPCR FOR THE ANALYSIS OF DNA FRAGMENTS. THE RESULTS SHOWED AN ENRICHMENT OF THE HISTONE MODIFICATION H4K12AC IN THE GPR55 GENE OF MDDCS TREATED WITH ETHANOL. FURTHERMORE, SIRNA AGAINST THE HISTONE ACETYLTRANSFERASE TIP60 (RESPONSIBLE FOR THE ACETYLATION OF H4K12) RESULTED IN A DOWNREGULATION OF GPR55. IN CONJUNCTION, THESE RESULTS INDICATE THAT IN THE PRESENCE OF ETHANOL, THE UPREGULATION OF GPR55 EXPRESSION IS ACCOMPANIED BY H4K12 ACETYLATION, WHICH MIGHT HAVE A SIGNIFICANT EFFECT IN THE ABILITY OF THIS INNATE IMMUNE SYSTEM'S CELLS TO COPE WITH CELLULAR STRESS INDUCED BY ETHANOL. HOWEVER, THE CAUSALITY OF ETHANOL REGULATION OF H4K12AC IN GPR55 EXPRESSION CHANGES STILL LACKS FURTHER ELUCIDATION; THEREFORE, ADDITIONAL EXPERIMENTAL APPROACHES TO CONFIRM A SIGNIFICANT CAUSALITY BETWEEN H4K12 ACETYLATION AND ETHANOL REGULATION OF GPR55 ARE CURRENTLY UNDERGOING IN OUR LAB. 2018