1 1987 137 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 2 6663 46 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 3 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 4 6661 39 UPREGULATION OF DNA METHYLTRANSFERASE-MEDIATED GENE SILENCING, ANCHORAGE-INDEPENDENT GROWTH, AND MIGRATION OF COLON CANCER CELLS BY INTERLEUKIN-6. INFLAMMATORY BOWEL DISEASE IS CHARACTERIZED BY CHRONIC INFLAMMATION WHICH PREDISPOSES TO COLORECTAL CANCER. THE MECHANISMS BY WHICH INFLAMMATION PROMOTES TUMORIGENESIS ARE NOT FULLY KNOWN. WE AIMED TO INVESTIGATE THE LINKS BETWEEN COLONIC INFLAMMATION AND TUMORIGENESIS VIA EPIGENETIC GENE SILENCING. COLON CANCER SPECIMENS WERE ASSESSED FOR THE EXPRESSION OF DNA METHYLTRANSFERASE-1 (DNMT-1) USING IMMUNOHISTOCHEMISTRY. COLORECTAL CARCINOMA CELL LINES WERE ASSESSED FOR DNMT1 EXPRESSION, METHYLCYTOSINE CONTENT, PROMOTER METHYLATION, GENE EXPRESSION, AND TUMORIGENESIS IN RESPONSE TO INTERLEUKIN (IL)-6. DNMT1 WAS EXPRESSED AT HIGHER LEVELS IN BOTH THE PERITUMORAL STROMA AND TUMOR IN INFLAMMATORY BOWEL DISEASE-ASSOCIATED CANCERS COMPARED WITH SPORADIC COLON CANCERS. IL-6 TREATMENT OF COLON CANCER CELLS RESULTED IN AN INCREASE IN DNMT1 EXPRESSION, INDEPENDENT OF DE NOVO GENE EXPRESSION. IL-6 INCREASED THE METHYLATION OF PROMOTER REGIONS OF GENES ASSOCIATED WITH TUMOR SUPPRESSION, ADHESION, AND APOPTOSIS RESISTANCE. EXPRESSION OF A SUBSET OF THESE GENES WAS DOWNREGULATED BY IL-6, AN EFFECT THAT WAS PREVENTED BY PREINCUBATION WITH 5-AZADEOXYCYTIDINE, A DNMT1 INHIBITOR. ANCHORAGE-INDEPENDENT GROWTH AND MIGRATION OF COLON CANCER CELLS WAS ALSO INCREASED BY IL-6 IN A 5-AZADEOXYCYTIDINE-SENSITIVE MANNER. OUR RESULTS INDICATE THAT DNMT-MEDIATED GENE SILENCING MAY PLAY A ROLE IN INFLAMMATION-ASSOCIATED COLON TUMORIGENESIS. 2010 5 1993 40 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 6 3795 36 INTERLEUKIN-6 CONTRIBUTES TO GROWTH IN CHOLANGIOCARCINOMA CELLS BY ABERRANT PROMOTER METHYLATION AND GENE EXPRESSION. THE ASSOCIATION BETWEEN CHRONIC INFLAMMATION AND THE DEVELOPMENT AND PROGRESSION OF MALIGNANCY IS EXEMPLIFIED IN THE BILIARY TRACT WHERE PERSISTENT INFLAMMATION STRONGLY PREDISPOSES TO CHOLANGIOCARCINOMA. THE INFLAMMATORY CYTOKINE INTERLEUKIN-6 (IL-6) ENHANCES TUMOR GROWTH IN CHOLANGIOCARCINOMA BY ALTERED GENE EXPRESSION VIA AUTOCRINE MECHANISMS. IL-6 CAN REGULATE THE ACTIVITY OF DNA METHYLTRANSFERASES, AND MOREOVER, ABERRANT DNA METHYLATION CAN CONTRIBUTE TO CARCINOGENESIS. WE THEREFORE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO IL-6 ON METHYLATION-DEPENDENT GENE EXPRESSION AND TRANSFORMED CELL GROWTH IN HUMAN CHOLANGIOCARCINOMA. THE RELATIONSHIP BETWEEN AUTOCRINE IL-6 PATHWAYS, DNA METHYLATION, AND TRANSFORMED CELL GROWTH WAS ASSESSED USING MALIGNANT CHOLANGIOCYTES STABLY TRANSFECTED TO OVEREXPRESS IL-6. TREATMENT WITH THE DNA METHYLATION INHIBITOR 5-AZA-2'-DEOXYCYTIDINE DECREASED CELL PROLIFERATION, GROWTH IN SOFT AGAR, AND METHYLCYTOSINE CONTENT OF MALIGNANT CHOLANGIOCYTES. HOWEVER, THIS EFFECT WAS NOT OBSERVED IN IL-6-OVEREXPRESSING CELLS. IL-6 OVEREXPRESSION RESULTED IN THE ALTERED EXPRESSION AND PROMOTER METHYLATION OF SEVERAL GENES, INCLUDING THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR). EGFR PROMOTER METHYLATION WAS DECREASED AND GENE AND PROTEIN EXPRESSION WAS INCREASED BY IL-6. THUS, EPIGENETIC REGULATION OF GENE EXPRESSION BY IL-6 CAN CONTRIBUTE TO TUMOR PROGRESSION BY ALTERING PROMOTER METHYLATION AND GENE EXPRESSION OF GROWTH-REGULATORY PATHWAYS, SUCH AS THOSE INVOLVING EGFR. MOREOVER, ENHANCED IL-6 EXPRESSION MAY DECREASE THE SENSITIVITY OF TUMOR CELLS TO THERAPEUTIC TREATMENTS USING METHYLATION INHIBITORS. THESE OBSERVATIONS HAVE IMPORTANT IMPLICATIONS FOR CANCER TREATMENT AND PROVIDE A MECHANISM BY WHICH PERSISTENT CYTOKINE STIMULATION CAN PROMOTE TUMOR GROWTH. 2006 7 975 40 CHRONIC OCCUPATIONAL EXPOSURE TO ARSENIC INDUCES CARCINOGENIC GENE SIGNALING NETWORKS AND NEOPLASTIC TRANSFORMATION IN HUMAN LUNG EPITHELIAL CELLS. CHRONIC ARSENIC EXPOSURE REMAINS A HUMAN HEALTH RISK; HOWEVER A CLEAR MODE OF ACTION TO UNDERSTAND GENE SIGNALING-DRIVEN ARSENIC CARCINOGENESIS IS CURRENTLY LACKING. THIS STUDY CHRONICALLY EXPOSED HUMAN LUNG EPITHELIAL BEAS-2B CELLS TO LOW-DOSE ARSENIC TRIOXIDE TO ELUCIDATE CANCER PROMOTING GENE SIGNALING NETWORKS ASSOCIATED WITH ARSENIC-TRANSFORMED (B-AS) CELLS. FOLLOWING A 6MONTH EXPOSURE, EXPOSED CELLS WERE ASSESSED FOR ENHANCED CELL PROLIFERATION, COLONY FORMATION, INVASION ABILITY AND IN VIVO TUMOR FORMATION COMPARED TO CONTROL CELL LINES. COLLECTED MRNA WAS SUBJECTED TO WHOLE GENOME EXPRESSION MICROARRAY PROFILING FOLLOWED BY IN SILICO INGENUITY PATHWAY ANALYSIS (IPA) TO IDENTIFY LUNG CARCINOGENESIS MODES OF ACTION. B-AS CELLS DISPLAYED SIGNIFICANT INCREASES IN PROLIFERATION, COLONY FORMATION AND INVASION ABILITY COMPARED TO BEAS-2B CELLS. B-AS INJECTIONS INTO NUDE MICE RESULTED IN DEVELOPMENT OF PRIMARY AND SECONDARY METASTATIC TUMORS. ARSENIC EXPOSURE RESULTED IN WIDESPREAD UP-REGULATION OF GENES ASSOCIATED WITH MITOCHONDRIAL METABOLISM AND INCREASED REACTIVE OXYGEN SPECIES PROTECTION SUGGESTING MITOCHONDRIAL DYSFUNCTION. CARCINOGENIC INITIATION VIA REACTIVE OXYGEN SPECIES AND EPIGENETIC MECHANISMS WAS FURTHER SUPPORTED BY ALTERED DNA REPAIR, HISTONE, AND ROS-SENSITIVE SIGNALING. NF-KAPPAB, MAPK AND NCOR1 SIGNALING DISRUPTED PPARALPHA/DELTA-MEDIATED LIPID HOMEOSTASIS. A 'PRO-CANCER' GENE SIGNALING NETWORK IDENTIFIED INCREASED SURVIVAL, PROLIFERATION, INFLAMMATION, METABOLISM, ANTI-APOPTOSIS AND MOBILITY SIGNALING. IPA-RANKED SIGNALING NETWORKS IDENTIFIED ALTERED P21, EF1ALPHA, AKT, MAPK, AND NF-KAPPAB SIGNALING NETWORKS PROMOTING GENETIC DISORDER, ALTERED CELL CYCLE, CANCER AND CHANGES IN NUCLEIC ACID AND ENERGY METABOLISM. IN CONCLUSION, TRANSFORMED B-AS CELLS WITH THEIR WHOLE GENOME EXPRESSION PROFILE PROVIDE AN IN VITRO ARSENIC MODEL FOR FUTURE LUNG CANCER SIGNALING RESEARCH AND DATA FOR CHRONIC ARSENIC EXPOSURE RISK ASSESSMENT. 2012 8 3658 37 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 9 1557 26 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 10 1500 38 DNA METHYLATION ANALYSIS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE THAT IS CHARACTERIZED BY ABERRANT CROSS-TALK BETWEEN KERATINOCYTES AND IMMUNE CELLS SUCH AS CD4+ T CELLS, RESULTING IN KERATINOCYTE HYPERPROLIFERATION IN THE EPIDERMIS. DNA METHYLATION, ONE OF SEVERAL EPIGENETIC MECHANISMS, PLAYS AN IMPORTANT ROLE IN GENE EXPRESSION WITHOUT CHANGING THE DNA SEQUENCE. SEVERAL STUDIES HAVE SUGGESTED THE INVOLVEMENT OF EPIGENETIC REGULATION IN SKIN LESIONS FROM PATIENTS WITH PSORIASIS. IN THIS STUDY, WE INVESTIGATED THE GENOME-WIDE DNA METHYLATION STATUS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS COMPARED WITH HEALTHY SUBJECTS USING METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING (MEDIP-SEQ). THE RESULTS OF MEDIP-SEQ SHOWED THAT THE GLOBAL METHYLATION VALUES OF CD4+ T CELLS ARE HIGHER IN PATIENTS WITH PSORIASIS THAN IN HEALTHY CONTROLS, PARTICULARLY IN THE PROMOTER REGIONS. AMONG THE MOST HYPERMETHYLATED GENES IN THE PROMOTER REGIONS, WE SELECTED THE GENES WHOSE EXPRESSION IS SIGNIFICANTLY REDUCED IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. STUDIES USING THE METHYLATION INHIBITOR 5-AZACYTIDINE IN VITRO METHYLATION ASSAYS HAVE SHOWN THAT THE DIFFERENTIAL EXPRESSION LEVELS WERE ASSOCIATED WITH THE METHYLATION STATUS OF EACH GENE. BISULFITE SEQUENCING OF THE TRANSCRIPTION START REGION OF PHOSPHATIDIC ACID PHOSPHATASE TYPE 2 DOMAIN CONTAINING 3 (PPAPDC3), ONE OF THE SELECTED GENES, SHOWED HYPERMETHYLATION IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. THESE RESULTS SUGGESTED THAT THE METHYLATION STATUS, WHICH IS IDENTIFIED BY MEDIP-SEQ OF THE GENES, WAS CORRELATED WITH THE MRNA EXPRESSION LEVEL OF THE GENES. COLLECTIVELY, THE DNA METHYLATION STATUS IN CD4+ T CELLS MIGHT BE ASSOCIATED WITH THE PATHOGENESIS OF PSORIASIS. 2014 11 902 36 CHRONIC EXPOSURE TO ARSENIC, ESTROGEN, AND THEIR COMBINATION CAUSES INCREASED GROWTH AND TRANSFORMATION IN HUMAN PROSTATE EPITHELIAL CELLS POTENTIALLY BY HYPERMETHYLATION-MEDIATED SILENCING OF MLH1. BACKGROUND: CHRONIC EXPOSURE TO ARSENIC AND ESTROGEN IS ASSOCIATED WITH RISK OF PROSTATE CANCER, BUT THEIR MECHANISM IS NOT FULLY UNDERSTOOD. ADDITIONALLY, THE CARCINOGENIC EFFECTS OF THEIR CO-EXPOSURE ARE NOT KNOWN. THEREFORE, THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE EFFECTS OF CHRONIC EXPOSURE TO ARSENIC, ESTROGEN, AND THEIR COMBINATION, ON CELL GROWTH AND TRANSFORMATION, AND IDENTIFY THE MECHANISM BEHIND THESE EFFECTS. METHODS: RWPE-1 HUMAN PROSTATE EPITHELIAL CELLS WERE CHRONICALLY EXPOSED TO ARSENIC AND ESTROGEN ALONE AND IN COMBINATION. CELL GROWTH WAS MEASURED BY CELL COUNT AND CELL CYCLE, WHEREAS CELL TRANSFORMATION WAS EVALUATED BY COLONY FORMATION ASSAY. GENE EXPRESSION WAS MEASURED BY QUANTITATIVE REAL-TIME PCR AND CONFIRMED AT PROTEIN LEVEL BY WESTERN BLOT ANALYSIS. MLH1 PROMOTER METHYLATION WAS DETERMINED BY PYROSEQUENCING METHOD. RESULTS: EXPOSURE TO ARSENIC, ESTROGEN, AND THEIR COMBINATIONS INCREASES CELL GROWTH AND TRANSFORMATION IN RWPE-1 CELLS. INCREASED EXPRESSION OF CYCLIN D1 AND BCL2, WHEREAS DECREASED EXPRESSION OF MISMATCH REPAIR GENES MSH4, MSH6, AND MLH1 WAS ALSO OBSERVED. HYPERMETHYLATION OF MLH1 PROMOTER FURTHER SUGGESTED THE EPIGENETIC INACTIVATION OF MLH1 EXPRESSION IN ARSENIC AND ESTROGEN TREATED CELLS. ARSENIC AND ESTROGEN COMBINATION CAUSED GREATER CHANGES THAN THEIR INDIVIDUAL TREATMENTS. CONCLUSIONS: FINDINGS OF THIS STUDY FOR THE FIRST TIME SUGGEST THAT ARSENIC AND ESTROGEN EXPOSURES CAUSE INCREASED CELL GROWTH AND SURVIVAL POTENTIALLY THROUGH EPIGENETIC INACTIVATION OF MLH1 RESULTING IN DECREASED MLH1-MEDIATED APOPTOTIC RESPONSE, AND CONSEQUENTLY INCREASED CELLULAR TRANSFORMATION. 2013 12 2747 36 EXPRESSION ANALYSIS OF THE EPIGENETIC METHYLTRANSFERASES AND METHYL-CPG BINDING PROTEIN FAMILIES IN THE NORMAL B-CELL AND B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). THE IMPORTANCE OF EPIGENETIC MODIFICATIONS IN CARCINOGENESIS HAS BEEN A SOURCE OF CONTROVERSY FOR SOME TIME. THERE IS LITTLE DOUBT THAT CHANGES IN GENOMIC HYPERMETHYLATION CONTRIBUTE TO THE SILENCING OF TUMOR SUPPRESSOR GENES. FURTHERMORE, RECENT STUDIES HAVE ALSO IDENTIFIED THE SIGNIFICANCE OF GENOMIC HYPOMETHYLATION ASSOCIATED WITH CHROMOSOMAL INSTABILITY AND TUMORIGENESIS. ONE OF THE MOST PERPLEXING QUESTIONS REGARDING EPIGENETIC MODIFICATIONS AND LEUKEMOGENESIS IS THE RELATIONSHIP WITH DNA METHYLTRANSFERASES (DNMT'S). THE PRIMARY FUNCTION OF THE DNMT ENZYMES IS TO METHYLATE GENOMIC DNA, WHEREAS THE METHYL-CPG BINDING DOMAIN PROTEINS (MBD) INTERPRET THIS METHYLATION SIGNAL AND REGULATE GENE EXPRESSION AND CHROMATIN BEHAVIOR. IN THIS STUDY WE ANALYSE THESE GENE FAMILIES BY QUANTITATIVE REAL-TIME PCR TO INVESTIGATE WHETHER EXPRESSION LEVELS AND THE B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL) PHENOTYPE ARE ASSOCIATED. FURTHERMORE, GIVEN THE EPIGENETIC CROSSTALK BETWEEN GENOME STABILITY AND THE HISTONE CHROMATIN CODE WE HAVE ANALYSED EUKARYOTIC HISTONE METHYLTRANSFERASE (EU-HMTASEI). SURPRISINGLY, WE DID NOT OBSERVE SIGNIFICANT CHANGES IN DNMT1 EXPRESSION IN B-CLL CASES WHEN COMPARED TO NORMAL LYMPHOCYTES, REGARDLESS OF WHETHER WE NORMALISE AGAINST GAPDH OR PCNA AS REFERENCE STANDARDS. INDEED, EXPRESSION OF THE MAINTENANCE AND DE NOVO METHYLASES WERE INDEPENDENTLY REGULATED. OF PARTICULAR NOTE WAS THE SIGNIFICANT DOWN REGULATION OF DNMT3B. FURTHERMORE, WE OBSERVED A POSITIVE CORRELATION BETWEEN HMTASEI EXPRESSION LEVELS AND STAGE OF LEUKEMIA SUGGESTING THAT CHANGES IN THE METHYLATION PATTERNS IN B-CLL MAY REPRESENT DEREGULATION OF THE EPIGENETIC REPERTOIRE THAT ALSO INCLUDE THE METHYLATION DEPENDENT BINDING PROTEINS, MBD2 AND MECP2. WE ENVISAGE CHANGES IN THE EPIGENETIC PROGRAM ARE MULTIFACTORIAL IN NATURE AND POSTULATE THAT THE PREVALENT GENOMIC METHYLASES JUST ONE COMPONENT OF A LARGER EPIGENETIC REPERTOIRE. 2004 13 6562 33 TRANSIENT AND PERMANENT CHANGES IN DNA METHYLATION PATTERNS IN INORGANIC ARSENIC-MEDIATED EPITHELIAL-TO-MESENCHYMAL TRANSITION. CHRONIC LOW DOSE INORGANIC ARSENIC EXPOSURE CAUSES CELLS TO TAKE ON AN EPITHELIAL-TO-MESENCHYMAL PHENOTYPE, WHICH IS A CRUCIAL PROCESS IN CARCINOGENESIS. INORGANIC ARSENIC IS NOT A MUTAGEN AND THUS EPIGENETIC ALTERATIONS HAVE BEEN IMPLICATED IN THIS PROCESS. INDEED, DURING THE EPITHELIAL-TO-MESENCHYMAL TRANSITION, MORPHOLOGIC CHANGES TO CELLS CORRELATE WITH CHANGES IN CHROMATIN STRUCTURE AND GENE EXPRESSION, ULTIMATELY DRIVING THIS PROCESS. HOWEVER, STUDIES ON THE EFFECTS OF INORGANIC ARSENIC EXPOSURE/WITHDRAWAL ON THE EPITHELIAL-TO-MESENCHYMAL TRANSITION AND THE IMPACT OF EPIGENETIC ALTERATIONS IN THIS PROCESS ARE LIMITED. IN THIS STUDY WE USED HIGH-RESOLUTION MICROARRAY ANALYSIS TO MEASURE THE CHANGES IN DNA METHYLATION IN CELLS UNDERGOING INORGANIC ARSENIC-INDUCED EPITHELIAL-TO-MESENCHYMAL TRANSITION, AND ON THE REVERSAL OF THIS PROCESS, AFTER REMOVAL OF THE INORGANIC ARSENIC EXPOSURE. WE FOUND THAT CELLS EXPOSED TO CHRONIC, LOW-DOSE INORGANIC ARSENIC EXPOSURE SHOWED 30,530 SITES WERE DIFFERENTIALLY METHYLATED, AND WITH INORGANIC ARSENIC WITHDRAWAL SEVERAL DIFFERENTIAL METHYLATED SITES WERE REVERSED, ALBEIT NOT COMPLETELY. FURTHERMORE, THESE CHANGES IN DNA METHYLATION MAINLY CORRELATED WITH CHANGES IN GENE EXPRESSION AT MOST SITES TESTED BUT NOT AT ALL. THIS STUDY SUGGESTS THAT DNA METHYLATION CHANGES ON GENE EXPRESSION ARE NOT CLEAR-CUT AND PROVIDE A PLATFORM TO BEGIN TO UNCOVER THE RELATIONSHIP BETWEEN DNA METHYLATION AND GENE EXPRESSION, SPECIFICALLY WITHIN THE CONTEXT OF INORGANIC ARSENIC TREATMENT. 2017 14 141 36 ABERRANT DNA METHYLATION OF MTOR PATHWAY GENES PROMOTES INFLAMMATORY ACTIVATION OF IMMUNE CELLS IN DIABETIC KIDNEY DISEASE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF DIABETIC KIDNEY DISEASE (DKD), BUT THE UNDERLYING MECHANISMS REMAIN UNCLEAR. IN THIS STUDY, WE TESTED THE HYPOTHESIS THAT ABERRANT DNA METHYLATION IN PERIPHERAL IMMUNE CELLS CONTRIBUTES TO DKD PROGRESSION. WE SHOWED THAT LEVELS OF DNA METHYLTRANSFERASE 1 (DNMT1), A KEY ENZYME FOR DNA METHYLATION, WERE INCREASED ALONG WITH INFLAMMATORY ACTIVITY OF PERIPHERAL BLOOD MONONUCLEAR CELLS IN DKD PATIENTS. INHIBITION OF DNMT1 WITH 5-AZA-2'-DEOXYCYTIDINE (5-AZA) MARKEDLY INCREASED THE PROPORTION OF CD4(+)CD25(+) REGULATORY T CELLS IN PERIPHERAL BLOOD MONONUCLEAR CELLS IN CULTURE AND IN DIABETIC ANIMALS. ADOPTIVE TRANSFER OF IMMUNE CELLS FROM 5-AZA-TREATED ANIMALS SHOWED BENEFICIAL EFFECTS ON THE HOST IMMUNE SYSTEM, RESULTING IN A SIGNIFICANT IMPROVEMENT OF DKD. USING GENOME-WIDE DNA METHYLATION ASSAYS, WE IDENTIFIED THE DIFFERENTIALLY METHYLATED CYTOSINES IN THE PROMOTER REGIONS OF MAMMALIAN TARGET OF RAPAMYCIN (MTOR) REGULATORS IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF DIABETIC PATIENTS. FURTHER, MRNA ARRAYS CONFIRMED THE CONSISTENT INDUCTION OF GENES EXPRESSED IN THE MTOR PATHWAY. IMPORTANTLY, DOWN-REGULATION OF DNMT1 EXPRESSION VIA RNA INTERFERENCE RESULTED IN PROMINENT CYTOSINE DEMETHYLATION OF MTOR NEGATIVE REGULATORS AND SUBSEQUENT DECREASE OF MTOR ACTIVITY. LASTLY, MODULATION OF MTOR RESULTED IN CHANGES IN THE EFFECT OF 5-AZA ON DIABETIC IMMUNE CELLS. THUS, UP-REGULATION OF DNMT1 IN DIABETIC IMMUNE CELLS INDUCES ABERRANT CYTOSINE METHYLATION OF THE UPSTREAM REGULATORS OF MTOR, LEADING TO PATHOGENIC ACTIVATION OF THE MTOR PATHWAY AND CONSEQUENT INFLAMMATION IN DIABETIC KIDNEYS. HENCE, THIS STUDY HIGHLIGHTS THERAPEUTIC POTENTIAL OF TARGETING EPIGENETIC EVENTS IN IMMUNE SYSTEM FOR TREATING DKD. 2019 15 922 36 CHRONIC IL-1BETA-INDUCED INFLAMMATION REGULATES EPITHELIAL-TO-MESENCHYMAL TRANSITION MEMORY PHENOTYPES VIA EPIGENETIC MODIFICATIONS IN NON-SMALL CELL LUNG CANCER. CHRONIC INFLAMMATION FACILITATES TUMOR PROGRESSION. WE DISCOVERED THAT A SUBSET OF NON-SMALL CELL LUNG CANCER CELLS UNDERWENT A GRADUALLY PROGRESSING EPITHELIAL-TO-MESENCHYMAL (EMT) PHENOTYPE FOLLOWING A 21-DAY EXPOSURE TO IL-1BETA, AN ABUNDANT PROINFLAMMATORY CYTOKINE IN THE AT-RISK FOR LUNG CANCER PULMONARY AND THE LUNG TUMOR MICROENVIRONMENTS. PATHWAY ANALYSIS OF THE GENE EXPRESSION PROFILE AND IN VITRO FUNCTIONAL STUDIES REVEALED THAT THE EMT AND EMT-ASSOCIATED PHENOTYPES, INCLUDING ENHANCED CELL INVASION, PD-L1 UPREGULATION, AND CHEMORESISTANCE, WERE SUSTAINED IN THE ABSENCE OF CONTINUOUS IL-1BETA EXPOSURE. WE REFERRED TO THIS PHENOMENON AS EMT MEMORY. UTILIZING A DOXYCYCLINE-CONTROLLED SLUG EXPRESSION SYSTEM, WE FOUND THAT HIGH EXPRESSION OF THE TRANSCRIPTION FACTOR SLUG WAS INDISPENSABLE FOR THE ESTABLISHMENT OF EMT MEMORY. HIGH SLUG EXPRESSION IN TUMORS OF LUNG CANCER PATIENTS WAS ASSOCIATED WITH POOR SURVIVAL. CHEMICAL OR GENETIC INHIBITION OF SLUG UPREGULATION PREVENTED EMT FOLLOWING THE ACUTE IL-1BETA EXPOSURE BUT DID NOT REVERSE EMT MEMORY. CHROMATIN IMMUNOPRECIPITATION AND METHYLATION-SPECIFIC PCR FURTHER REVEALED A SLUG-MEDIATED TEMPORAL REGULATION OF EPIGENETIC MODIFICATIONS, INCLUDING ACCUMULATION OF H3K27, H3K9, AND DNA METHYLATION, IN THE CDH1 (E-CADHERIN) PROMOTER FOLLOWING THE CHRONIC IL-1BETA EXPOSURE. CHEMICAL INHIBITION OF DNA METHYLATION NOT ONLY RESTORED E-CADHERIN EXPRESSION IN EMT MEMORY, BUT ALSO PRIMED CELLS FOR CHEMOTHERAPY-INDUCED APOPTOSIS. 2020 16 482 40 ARSENITE BINDS TO THE ZINC FINGER MOTIF OF TIP60 HISTONE ACETYLTRANSFERASE AND INDUCES ITS DEGRADATION VIA THE 26S PROTEASOME. ARSENIC IS A UBIQUITOUS ENVIRONMENTAL CONTAMINANT WITH WIDESPREAD PUBLIC HEALTH CONCERN. EPIDEMIOLOGICAL STUDIES HAVE REVEALED THAT CHRONIC HUMAN EXPOSURE TO ARSENIC IN DRINKING WATER IS ASSOCIATED WITH THE PREVALENCE OF SKIN, LUNG, AND BLADDER CANCERS. ABERRANT HISTONE MODIFICATIONS (E.G., METHYLATION, ACETYLATION, AND UBIQUITINATION) WERE PREVIOUSLY FOUND TO BE ACCOMPANIED BY ARSENIC EXPOSURE; THUS, PERTURBATION OF EPIGENETIC PATHWAYS IS THOUGHT TO CONTRIBUTE TO ARSENIC CARCINOGENESIS. ARSENITE IS KNOWN TO INTERACT WITH ZINC FINGER MOTIFS OF PROTEINS, AND ZINC FINGER MOTIF IS PRESENT IN AND INDISPENSABLE FOR THE ENZYMATIC ACTIVITIES OF CRUCIAL HISTONE-MODIFYING ENZYMES ESPECIALLY THE MYST FAMILY OF HISTONE ACETYLTRANSFERASES (E.G., TIP60). HENCE, WE REASONED THAT TRIVALENT ARSENIC MAY TARGET THE ZINC FINGER MOTIF OF THESE ENZYMES, DISTURB THEIR ENZYMATIC ACTIVITIES, AND ALTER HISTONE ACETYLATION. HEREIN, WE FOUND THAT AS(3+) COULD BIND DIRECTLY TO THE ZINC-FINGER MOTIF OF TIP60 IN VITRO AND IN CELLS. IN ADDITION, EXPOSURE TO AS(3+) COULD LEAD TO A DOSE-DEPENDENT DECREASE IN TIP60 PROTEIN LEVEL VIA THE UBIQUITIN-PROTEASOME PATHWAY. THUS, THE RESULTS FROM THE PRESENT STUDY REVEALED, FOR THE FIRST TIME, THAT ARSENITE MAY TARGET CYSTEINE RESIDUES IN THE ZINC-FINGER MOTIF OF THE TIP60 HISTONE ACETYLTRANSFERASE, THEREBY ALTERING THE H4K16AC HISTONE EPIGENETIC MARK. OUR RESULTS ALSO SHED SOME NEW LIGHT ON THE MECHANISMS UNDERLYING THE ARSENIC-INDUCED EPIGENOTOXICITY AND CARCINOGENESIS IN HUMANS. 2017 17 473 32 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 4014 38 LOW-DOSE CD INDUCES HEPATIC GENE HYPERMETHYLATION, ALONG WITH THE PERSISTENT REDUCTION OF CELL DEATH AND INCREASE OF CELL PROLIFERATION IN RATS AND MICE. BACKGROUND: CADMIUM (CD) IS CLASSIFIED AS A HUMAN CARCINOGEN PROBABLY ASSOCIATED WITH EPIGENETIC CHANGES. DNA METHYLATION IS ONE OF EPIGENETIC MECHANISMS BY WHICH CELLS CONTROL GENE EXPRESSION. THEREFORE, THE PRESENT STUDY GENOME-WIDELY SCREENED THE METHYLATION-ALTERED GENES IN THE LIVER OF RATS PREVIOUSLY EXPOSED TO LOW-DOSE CD. METHODOLOGY PRINCIPAL FINDINGS: RATS WERE EXPOSED TO CD AT 20 NMOL/KG EVERY OTHER DAY FOR 4 WEEKS AND GENE METHYLATION WAS ANALYZED AT THE 48(TH) WEEK WITH METHYLATED DNA IMMUNOPRECIPITATION-CPG ISLAND MICROARRAY. AMONG THE 1629 ALTERED GENES, THERE WERE 675 GENES WHOSE PROMOTER CPG ISLANDS (CGIS) WERE HYPERMETHYLATED, 899 GENES WHOSE PROMOTER CGIS WERE HYPOMETHYLATED, AND 55 GENES WHOSE PROMOTER CGIS WERE MIXED WITH HYPER- AND HYPO-METHYLATION. CASPASE-8 GENE PROMOTER CGIS AND TNF GENE PROMOTER CGIS WERE HYPERMETHYLATED AND HYPOMETHYLATED, RESPECTIVELY, ALONG WITH A LOW APOPTOSIS RATE IN CD-TREATED RAT LIVERS. TO LINK THE ABERRANT METHYLATION OF CASPASE-8 AND TNF GENES TO THE LOW APOPTOSIS INDUCED BY LOW-DOSE CD, MICE WERE GIVEN CHRONIC EXPOSURE TO LOW-DOSE CD WITH AND WITHOUT METHYLATION INHIBITOR (5-AZA-2'-DEOXYCTIDENE, 5-AZA). AT THE 48(TH) WEEK AFTER CD EXPOSURE, LIVERS FROM CD-TREATED MICE DISPLAYED THE INCREASED CASPASE-8 CGI METHYLATION AND DECREASED CASPASE-8 PROTEIN EXPRESSION, ALONG WITH SIGNIFICANT INCREASES IN CELL PROLIFERATION AND OVEREXPRESSION OF TGF-BETA1 AND CYTOKERATIN 8/18 (THE LATTER IS A NEW MARKER OF MOUSE LIVER PRENEOPLASTIC LESIONS), ALL WHICH WERE PREVENTED BY 5-AZA TREATMENT. CONCLUSION/SIGNIFICANCE: THESE RESULTS SUGGEST THAT CD-INDUCED GLOBAL GENE HYPERMETHYLATION, MOST LIKELY CASPASE-8 GENE PROMOTER HYPERMETHYLATION THAT DOWN-REGULATED ITS EXPRESSION, LEADING TO THE DECREASED HEPATIC APOPTOSIS AND INCREASED PRENEOPLASTIC LESIONS. 2012 19 1723 38 DYSREGULATION OF C-X-C MOTIF LIGAND 10 DURING AGING AND ASSOCIATION WITH COGNITIVE PERFORMANCE. CHRONIC LOW-GRADE INFLAMMATION DURING AGING (INFLAMMAGING) IS ASSOCIATED WITH COGNITIVE DECLINE AND NEURODEGENERATION; HOWEVER, THE MECHANISMS UNDERLYING INFLAMMAGING ARE UNCLEAR. WE STUDIED A POPULATION (N = 361) OF HEALTHY YOUNG AND OLD ADULTS FROM THE MYOAGE COHORT. PERIPHERAL LEVELS OF C-X-C MOTIF CHEMOKINE LIGAND 10 (CXCL10) WAS FOUND TO BE HIGHER IN OLDER ADULTS, COMPARED WITH YOUNG, AND NEGATIVELY ASSOCIATED WITH WORKING MEMORY PERFORMANCE. THIS COINCIDED WITH AN AGE-RELATED REDUCTION IN BLOOD DNA METHYLATION AT SPECIFIC CPGS WITHIN THE CXCL10 GENE PROMOTER. IN VITRO ANALYSIS SUPPORTED THE ROLE OF DNA METHYLATION IN REGULATING CXCL10 TRANSCRIPTION. A POLYMORPHISM (RS56061981) THAT ALTERED METHYLATION AT ONE OF THESE CPG SITES FURTHER ASSOCIATED WITH WORKING MEMORY PERFORMANCE IN 2 INDEPENDENT AGING COHORTS. STUDYING PREFRONTAL CORTEX SAMPLES, WE FOUND HIGHER CXCL10 PROTEIN LEVELS IN THOSE WITH ALZHEIMER'S DISEASE, COMPARED WITH AGED CONTROLS. THESE FINDINGS SUPPORT THE ASSOCIATION OF PERIPHERAL INFLAMMATION, AS DEMONSTRATED BY CXCL10, IN AGING AND COGNITIVE DECLINE. WE REVEAL AGE-RELATED EPIGENETIC AND GENETIC FACTORS WHICH CONTRIBUTE TO THE DYSREGULATION OF CXCL10. 2018 20 2297 30 EPIGENETIC REGULATION OF ACUTE INFLAMMATORY PAIN. ACUTE PAIN IS ASSOCIATED WITH TISSUE DAMAGE, WHICH RESULTS IN THE RELEASE OF INFLAMMATORY MEDIATORS. RECENT STUDIES POINT TO THE INVOLVEMENT OF EPIGENETIC MECHANISMS (DNA METHYLATION) IN THE DEVELOPMENT OF PAIN. WE HAVE FOUND THAT DURING ACUTE INFLAMMATORY PAIN INDUCED BY THE APPLICATION OF 10% MUSTARD OIL ON THE TONGUES OF RATS, LEVELS OF DNMT3A AND 3B WERE ELEVATED MARKEDLY (36 AND 42 % RESPECTIVELY), WHEREAS THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY. PREVIOUS INJECTION OF XEFOCAM WITH 0,4 MG/KG DOSE DECREASED LEVELS OF DNMT3A AND 3B (25 AND 24% RESPECTIVELY). THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY COMPARED TO THE CONTROL GROUP. THE FINDINGS SUPPORT THE IDEA THAT INHIBITORS OF DNA-METHYLTRANSFERASES COULD BE USEFUL FOR PAIN MANAGEMENT. OUR DATA SUGGEST THAT NSAIDS (ALONE OR IN COMBINATION WITH DNMT INHIBITORS) MAY BE PROPOSED AS POSSIBLE EPIGENETIC REGULATORY AGENTS, WHICH MAY PLAY A ROLE IN EPIGENETIC MECHANISMS INDIRECTLY THROUGH ALTERING THE ACTIVITY OF INFLAMMATORY MEDIATORS INVOLVED IN PAIN DEVELOPMENT. 2014