1 5949 101 TARGETING THE PRC2-DEPENDENT EPIGENETIC PROGRAM ALLEVIATES URINARY TRACT INFECTIONS. URINARY TRACT INFECTION (UTI) IS A PERVASIVE HEALTH PROBLEM WORLDWIDE. PATIENTS WITH A HISTORY OF UTIS SUFFER INCREASED RISK OF RECURRENT INFECTIONS, A MAJOR RISK OF ANTIBIOTIC RESISTANCE. HERE, WE SHOW THAT BLADDER INFECTIONS INDUCE EXPRESSION OF EZH2 IN BLADDER UROTHELIAL CELLS. EZH2 IS THE METHYLTRANSFERASE OF POLYCOMB REPRESSOR COMPLEX 2 (PRC2)-A POTENT EPIGENETIC REGULATOR. UROTHELIUM-SPECIFIC INACTIVATION OF PRC2 RESULTS IN REDUCED URINE BACTERIAL BURDEN, MUTED INFLAMMATORY RESPONSE, AND DECREASED ACTIVITY OF THE NF-KAPPAB SIGNALING PATHWAY. PRC2 INACTIVATION ALSO FACILITATES PROPER REGENERATION AFTER UROTHELIAL DAMAGE FROM UTIS, BY ATTENUATING BASAL CELL HYPERPLASIA AND INCREASING UROTHELIAL DIFFERENTIATION. IN ADDITION, TREATMENT WITH EZH2-SPECIFIC SMALL-MOLECULE INHIBITORS IMPROVES OUTCOMES OF THE CHRONIC AND SEVERE BLADDER INFECTIONS IN MICE. THESE FINDINGS COLLECTIVELY SUGGEST THAT THE PRC2-DEPENDENT EPIGENETIC REPROGRAMING CONTROLS THE AMPLITUDE OF INFLAMMATION AND SEVERITY OF UTIS AND THAT EZH2 INHIBITORS MAY BE A VIABLE NON-ANTIBIOTIC STRATEGY TO MANAGE CHRONIC AND SEVERE UTIS. 2023 2 473 25 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 3 2403 32 EPIGENETIC REPROGRAMMING: A POSSIBLE ETIOLOGICAL FACTOR IN BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS? PURPOSE: THE ETIOLOGY OF BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS IS POORLY UNDERSTOOD. THE POSSIBILITY THAT EPIGENETIC REPROGRAMMING MAY HAVE A ROLE IS DISCUSSED. MATERIALS AND METHODS: A LITERATURE SEARCH WAS PERFORMED WITH THE ENTREZ-PUBMED(R) DATABASE USING THE KEY WORDS URINARY BLADDER, EPIGENETICS, EPIGENETIC MECHANISMS, INTERSTITIAL CYSTITIS, DIAGNOSIS, ETIOLOGY, UROTHELIAL CELLS, MAST CELLS, NERVE FIBERS, NERVES, NERVE GROWTH FACTOR, RECURRENT INJURY, STEM CELLS, INFLAMMATORY MEDIATORS AND DEMETHYLASES. RESULTS: THE UROEPITHELIUM IS INTIMATELY ASSOCIATED WITH THE NERVOUS SYSTEM. SENSORY INPUT AT THE APICAL SURFACE OF UMBRELLA CELLS REGULATES BLADDER FUNCTION VIA A TRANSMURAL SIGNALING PATHWAY. WHEN UMBRELLA CELLS ARE SHED IN RESPONSE TO NOXIOUS STIMULI, STEM CELLS IN THE BASAL LAYER BECOME EXPOSED. THE POLYCOMB GROUP GENES ARE KEY IN THE MAINTENANCE OF ADULT STEM CELLS. THE POLYCOMB GROUP GENES MEDIATE GENE SILENCING AND REPRESS TRANSDIFFERENTIATION BY METHYLATING LYSINE 27 OF HISTONE H3 (H3K27ME3). JMJD3, AN ENZYME DEMETHYLATING H3K27ME3, ANTAGONIZES POLYCOMB GROUP GENES MEDIATED SILENCING. INFLAMMATORY STIMULI ARE STRONG INDUCERS OF JMJD3 AND MAY REVERSE GENE SILENCING IN STEM CELLS, MODIFYING THE DIFFERENTIATION PATTERN. EPIGENETIC PROCESSES INVOLVING H3K27 METHYLATION ARE MULTISTABLE PROCESSES. TRANSIENT SIGNALING, EG BY LIPOPOLYSACCHARIDE, TRIGGERS EPIGENETIC REPROGRAMMING AND ESTABLISHES ONE OF THE ALTERNATIVE REGULATORY STATES. ONCE ESTABLISHED SUCH STATES CAN BE MAINTAINED AND PROPAGATED EVEN IN THE ABSENCE OF THE INITIAL SIGNAL. CONCLUSIONS: WE POSTULATE THAT SIMILAR EPIGENETIC REPROGRAMMING MECHANISMS IN THE BLADDER MAY PROVIDE AN EXPLANATION FOR UROEPITHELIAL, MAST CELLS AND NERVE CELL ABNORMALITIES IN BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS, AS WELL AS PROPAGATION OF THIS ALTERED STATE IN THE ABSENCE OF THE SIGNAL THAT MAY HAVE TRIGGERED IT. IT ALSO PROVIDES A NEW EXPERIMENTAL PARADIGM FOR EXPLORING THE ETIOLOGY OF BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS. DATA SUPPORTING THIS HYPOTHESIS WOULD PROVIDE A RATIONALE FOR NEW DIAGNOSTIC AS WELL AS TREATMENT OPTIONS FOR BLADDER PAIN SYNDROME/INTERSTITIAL CYSTITIS. 2009 4 926 29 CHRONIC INFLAMMATION PATHWAY NF-KAPPAB COOPERATES WITH EPIGENETIC REPROGRAMMING TO DRIVE THE MALIGNANT PROGRESSION OF GLIOBLASTOMA. WITHOUT AN EFFECTIVE STRATEGY FOR TARGETED THERAPY, GLIOBLASTOMA IS STILL INCURABLE WITH A MEDIAN SURVIVAL OF ONLY 15 MONTHS. BOTH CHRONIC INFLAMMATION AND EPIGENETIC REPROGRAMMING ARE HALLMARKS OF CANCER. HOWEVER, THE MECHANISMS AND CONSEQUENCES OF THEIR COOPERATION IN GLIOBLASTOMA REMAIN UNKNOWN. HERE, WE DISCOVER THAT CHRONIC INFLAMMATION GOVERNS H3K27ME3 REPROGRAMMING IN GLIOBLASTOMA THROUGH THE CANONICAL NF-KAPPAB PATHWAY TO TARGET EZH2. BEING A CRUCIAL MEDIATOR OF CHRONIC INFLAMMATION, THE CANONICAL NF-KAPPAB SIGNALLING SPECIFICALLY DIRECTS THE EXPRESSION AND REDISTRIBUTION OF H3K27ME3 BUT NOT H3K4ME3, H3K9ME3 AND H3K36ME3. USING RNA-SEQ SCREENING TO FOCUS ON GENES ENCODING METHYLTRANSFERASES AND DEMETHYLASES OF HISTONE, WE IDENTIFY EZH2 AS A KEY METHYLTRANSFERASE TO CONTROL INFLAMMATION-TRIGGERED EPIGENETIC REPROGRAMMING IN GLIOMAGENESIS. MECHANISTICALLY, NF-KAPPAB SELECTIVELY DRIVES THE EXPRESSION OF EZH2 BY ACTIVATING ITS TRANSCRIPTION, CONSEQUENTLY RESULTING IN A GLOBAL CHANGE IN H3K27ME3 EXPRESSION AND DISTRIBUTION. FURTHERMORE, WE FIND THAT CO-ACTIVATION OF NF-KAPPAB AND EZH2 CONFERS THE POOREST CLINICAL OUTCOME, AND THAT THE RISK FOR GLIOBLASTOMA CAN BE ACCURATELY MOLECULARLY STRATIFIED BY NF-KAPPAB AND EZH2. IT IS NOTABLE THAT NF-KAPPAB CAN POTENTIALLY COOPERATE WITH EZH2 IN MORE THAN ONE WAY, AND MOST IMPORTANTLY, WE DEMONSTRATE A SYNERGISTIC EFFECT OF CANCER CELLS INDUCED BY COMBINATORY INHIBITION OF NF-KAPPAB AND EZH2, WHICH BOTH ARE FREQUENTLY OVER-ACTIVATED IN GLIOBLASTOMA. IN SUMMARY, WE UNCOVER A FUNCTIONAL COOPERATION BETWEEN CHRONIC INFLAMMATION AND EPIGENETIC REPROGRAMMING IN GLIOBLASTOMA, COMBINED TARGETING OF WHICH BY INHIBITORS GUARANTEED IN SAFETY AND AVAILABILITY FURNISHES A POTENT STRATEGY FOR EFFECTIVE TREATMENT OF THIS FATAL DISEASE. 2022 5 5292 26 PROSTATIC INFLAMMATION ENHANCES BASAL-TO-LUMINAL DIFFERENTIATION AND ACCELERATES INITIATION OF PROSTATE CANCER WITH A BASAL CELL ORIGIN. CHRONIC INFLAMMATION HAS BEEN SHOWN TO PROMOTE THE INITIATION AND PROGRESSION OF DIVERSE MALIGNANCIES BY INDUCING GENETIC AND EPIGENETIC ALTERATIONS. IN THIS STUDY, WE INVESTIGATE AN ALTERNATIVE MECHANISM THROUGH WHICH INFLAMMATION PROMOTES THE INITIATION OF PROSTATE CANCER. ADULT MURINE PROSTATE EPITHELIA ARE COMPOSED PREDOMINANTLY OF BASAL AND LUMINAL CELLS. PREVIOUS STUDIES REVEALED THAT THE TWO LINEAGES ARE LARGELY SELF-SUSTAINED WHEN RESIDING IN THEIR NATIVE MICROENVIRONMENT. TO INTERROGATE WHETHER TISSUE INFLAMMATION ALTERS THE DIFFERENTIATION PROGRAM OF BASAL CELLS, WE CONDUCTED LINEAGE TRACING OF BASAL CELLS USING A K14-CREER;MTMG MODEL IN CONCERT WITH A MURINE MODEL OF PROSTATITIS INDUCED BY INFECTION FROM THE UROPATHOGENIC BACTERIA CP9. WE SHOW THAT ACUTE PROSTATITIS CAUSES TISSUE DAMAGE AND CREATES A TISSUE MICROENVIRONMENT THAT INDUCES THE DIFFERENTIATION OF BASAL CELLS INTO LUMINAL CELLS, AN ALTERATION THAT RARELY OCCURS UNDER NORMAL PHYSIOLOGICAL CONDITIONS. PREVIOUSLY WE SHOWED THAT A MOUSE MODEL WITH PROSTATE BASAL CELL-SPECIFIC DELETION OF PHOSPHATASE AND TENSIN HOMOLOG (K14-CREER;PTEN(FL/FL)) DEVELOPS PROSTATE CANCER WITH A LONG LATENCY, BECAUSE DISEASE INITIATION IN THIS MODEL REQUIRES AND IS LIMITED BY THE DIFFERENTIATION OF TRANSFORMATION-RESISTANT BASAL CELLS INTO TRANSFORMATION-COMPETENT LUMINAL CELLS. HERE, WE SHOW THAT CP9-INDUCED PROSTATITIS SIGNIFICANTLY ACCELERATES THE INITIATION OF PROSTATIC INTRAEPITHELIAL NEOPLASIA IN THIS MODEL. OUR RESULTS DEMONSTRATE THAT INFLAMMATION RESULTS IN A TISSUE MICROENVIRONMENT THAT ALTERS THE NORMAL PROSTATE EPITHELIAL CELL DIFFERENTIATION PROGRAM AND THAT THROUGH THIS CELLULAR PROCESS INFLAMMATION ACCELERATES THE INITIATION OF PROSTATE CANCER WITH A BASAL CELL ORIGIN. 2014 6 2228 25 EPIGENETIC MODIFICATIONS OF HISTONES IN PERIODONTAL DISEASE. PERIODONTITIS IS A CHRONIC INFECTIOUS DISEASE DRIVEN BY DYSBIOSIS, AN IMBALANCE BETWEEN COMMENSAL BACTERIA AND THE HOST ORGANISM. PERIODONTITIS IS A LEADING CAUSE OF TOOTH LOSS IN ADULTS AND OCCURS IN ABOUT 50% OF THE US POPULATION. IN ADDITION TO THE CLINICAL CHALLENGES ASSOCIATED WITH TREATING PERIODONTITIS, THE PROGRESSION AND CHRONIC NATURE OF THIS DISEASE SERIOUSLY AFFECT HUMAN HEALTH. EMERGING EVIDENCE SUGGESTS THAT PERIODONTITIS IS ASSOCIATED WITH MECHANISMS BEYOND BACTERIA-INDUCED PROTEIN AND TISSUE DEGRADATION. HERE, WE HYPOTHESIZE THAT BACTERIA ARE ABLE TO INDUCE EPIGENETIC MODIFICATIONS IN ORAL EPITHELIAL CELLS MEDIATED BY HISTONE MODIFICATIONS. IN THIS STUDY, WE FOUND THAT DYSBIOSIS IN VIVO LED TO EPIGENETIC MODIFICATIONS, INCLUDING ACETYLATION OF HISTONES AND DOWNREGULATION OF DNA METHYLTRANSFERASE 1. IN ADDITION, IN VITRO EXPOSURE OF ORAL EPITHELIAL CELLS TO LIPOPOLYSACCHARIDES RESULTED IN HISTONE MODIFICATIONS, ACTIVATION OF TRANSCRIPTIONAL COACTIVATORS, SUCH AS P300/CBP, AND ACCUMULATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB). GIVEN THAT ORAL EPITHELIAL CELLS ARE THE FIRST LINE OF DEFENSE FOR THE PERIODONTIUM AGAINST BACTERIA, WE ALSO EVALUATED WHETHER ACTIVATION OF PATHOGEN RECOGNITION RECEPTORS INDUCED HISTONE MODIFICATIONS. WE FOUND THAT ACTIVATION OF THE TOLL-LIKE RECEPTORS 1, 2, AND 4 AND THE NUCLEOTIDE-BINDING OLIGOMERIZATION DOMAIN PROTEIN 1 INDUCED HISTONE ACETYLATION IN ORAL EPITHELIAL CELLS. OUR FINDINGS CORROBORATE THE EMERGING CONCEPT THAT EPIGENETIC MODIFICATIONS PLAY A ROLE IN THE DEVELOPMENT OF PERIODONTITIS. 2016 7 4497 28 MORPHINE LEADS TO GLOBAL GENOME CHANGES IN H3K27ME3 LEVELS VIA A POLYCOMB REPRESSIVE COMPLEX 2 (PRC2) SELF-REGULATORY MECHANISM IN MESCS. BACKGROUND: ENVIRONMENTALLY INDUCED EPIGENETIC CHANGES CAN LEAD TO HEALTH PROBLEMS OR DISEASE, BUT THE MECHANISMS INVOLVED REMAIN UNCLEAR. MORPHINE CAN PASS THROUGH THE PLACENTAL BARRIER LEADING TO ABNORMAL EMBRYO DEVELOPMENT. HOWEVER, THE MECHANISM BY WHICH MORPHINE CAUSES THESE EFFECTS AND HOW THEY SOMETIMES PERSIST INTO ADULTHOOD IS NOT WELL KNOWN. TO UNRAVEL THE MORPHINE-INDUCED CHROMATIN ALTERATIONS INVOLVED IN ABERRANT EMBRYO DEVELOPMENT, WE EXPLORED THE ROLE OF THE H3K27ME3/PRC2 REPRESSIVE COMPLEX IN GENE EXPRESSION AND ITS TRANSMISSION ACROSS CELLULAR GENERATIONS IN RESPONSE TO MORPHINE. RESULTS: USING MOUSE EMBRYONIC STEM CELLS AS A MODEL SYSTEM, WE FOUND THAT CHRONIC MORPHINE TREATMENT INDUCES A GLOBAL DOWNREGULATION OF THE HISTONE MODIFICATION H3K27ME3. CONVERSELY, CHIP-SEQ SHOWED A REMARKABLE INCREASE IN H3K27ME3 LEVELS AT SPECIFIC GENOMIC SITES, PARTICULARLY PROMOTERS, DISRUPTING SELECTIVE TARGET GENES RELATED TO EMBRYO DEVELOPMENT, CELL CYCLE AND METABOLISM. THROUGH A SELF-REGULATORY MECHANISM, MORPHINE DOWNREGULATED THE TRANSCRIPTION OF PRC2 COMPONENTS RESPONSIBLE FOR H3K27ME3 BY ENRICHING HIGH H3K27ME3 LEVELS AT THE PROMOTER REGION. DOWNREGULATION OF PRC2 COMPONENTS PERSISTED FOR AT LEAST 48 H (4 CELL CYCLES) FOLLOWING MORPHINE REMOVAL, THOUGH PROMOTER H3K27ME3 LEVELS RETURNED TO CONTROL LEVELS. CONCLUSIONS: MORPHINE INDUCES TARGETING OF THE PRC2 COMPLEX TO SELECTED PROMOTERS, INCLUDING THOSE OF PRC2 COMPONENTS, LEADING TO CHARACTERISTIC CHANGES IN GENE EXPRESSION AND A GLOBAL REDUCTION IN H3K27ME3. FOLLOWING MORPHINE REMOVAL, ENHANCED PROMOTER H3K27ME3 LEVELS REVERT TO NORMAL SOONER THAN GLOBAL H3K27ME3 OR PRC2 COMPONENT TRANSCRIPT LEVELS. WE SUGGEST THAT H3K27ME3 IS INVOLVED IN INITIATING MORPHINE-INDUCED CHANGES IN GENE EXPRESSION, BUT NOT IN THEIR MAINTENANCE. MODEL OF POLYCOMB REPRESSIVE COMPLEX 2 (PRC2) AND H3K27ME3 ALTERATIONS INDUCED BY CHRONIC MORPHINE EXPOSURE. MORPHINE INDUCES H3K27ME3 ENRICHMENT AT PROMOTERS OF GENES ENCODING CORE MEMBERS OF THE PRC2 COMPLEX AND IS ASSOCIATED WITH THEIR TRANSCRIPTIONAL DOWNREGULATION. 2020 8 4745 25 NOVEL INSIGHTS OF EZH2-MEDIATED EPIGENETIC MODIFICATIONS IN DEGENERATIVE MUSCULOSKELETAL DISEASES. DEGENERATIVE MUSCULOSKELETAL DISEASES (OSTEOPOROSIS, OSTEOARTHRITIS, DEGENERATIVE SPINAL DISEASE AND SARCOPENIA) ARE PATHOLOGICAL CONDITIONS THAT AFFECT THE FUNCTION AND PAIN OF TISSUES SUCH AS BONE, CARTILAGE, AND MUSCLES, AND ARE CLOSELY ASSOCIATED WITH AGEING AND LONG-TERM DEGENERATION. ENHANCER OF ZESTE HOMOLOG 2 (EZH2), AN IMPORTANT EPIGENETIC REGULATOR, REGULATES GENE EXPRESSION MAINLY THROUGH THE PRC2-DEPENDENT TRIMETHYLATION OF HISTONE H3 AT LYSINE 27 (H3K27ME3). INCREASING EVIDENCE SUGGESTS THAT EZH2 IS INVOLVED IN SEVERAL BIOLOGICAL PROCESSES CLOSELY RELATED TO DEGENERATIVE MUSCULOSKELETAL DISEASES, SUCH AS OSTEOGENIC-ADIPOGENIC DIFFERENTIATION OF BONE MARROW MESENCHYMAL STEM CELLS, OSTEOCLAST ACTIVATION, CHONDROCYTE FUNCTIONAL STATUS, AND SATELLITE CELL PROLIFERATION AND DIFFERENTIATION, MAINLY THROUGH EPIGENETIC REGULATION (H3K27ME3). THEREFORE, THE SYNTHESIS AND ELUCIDATION OF THE ROLE OF EZH2 IN DEGENERATIVE MUSCULOSKELETAL DISEASES HAVE ATTRACTED INCREASING ATTENTION. IN ADDITION, ALTHOUGH EZH2 INHIBITORS HAVE BEEN APPROVED FOR CLINICAL USE, WHETHER THEY CAN BE REPURPOSED FOR THE TREATMENT OF DEGENERATIVE MUSCULOSKELETAL DISEASES NEEDS TO BE CONSIDERED. HERE, WE REVIEWED THE ROLE OF EZH2 IN THE DEVELOPMENT OF DEGENERATIVE MUSCULOSKELETAL DISEASES AND BROUGHT FORWARD PROSPECTS OF ITS PHARMACOLOGICAL INHIBITORS IN THE IMPROVEMENT OF THE TREATMENT OF THE DISEASES. 2023 9 3527 28 IL-6 ENHANCES THE NUCLEAR TRANSLOCATION OF DNA CYTOSINE-5-METHYLTRANSFERASE 1 (DNMT1) VIA PHOSPHORYLATION OF THE NUCLEAR LOCALIZATION SEQUENCE BY THE AKT KINASE. THE EPIGENETIC PROGRAMMING OF GENOMIC DNA IS ACCOMPLISHED, IN PART, BY SEVERAL DNA CYTOSINE-5-METHYLTRANSFERASES THAT ACT BY COVALENTLY MODIFYING CYTOSINES WITH THE ADDITION OF A METHYL GROUP. THIS COVALENT MODIFICATION IS MAINTAINED BY THE DNA CYTOSINE-5-METHYLTRANSFERASE-1 ENZYME (DNMT1), WHICH IS CAPABLE OF ACTING IN CONCERT WITH OTHER SIMILAR ENZYMES TO SILENCE IMPORTANT TUMOR SUPPRESSOR GENES. IL-6 IS A MULTIFUNCTIONAL MEDIATOR OF INFLAMMATION, ACTING THROUGH SEVERAL MAJOR SIGNALING CASCADES, INCLUDING THE PHOSPHATIDYLINOSITOL-3-KINASE PATHWAY (PI-3-K), WHICH ACTIVATES PROTEIN KINASE B (AKT/PKB) DOWNSTREAM. HERE, WE SHOW THAT THE SUBCELLULAR LOCALIZATION OF DNMT1 CAN BE ALTERED BY THE ADDITION OF IL-6, INCREASING THE RATE OF NUCLEAR TRANSLOCATION OF THE ENZYME FROM THE CYTOSOLIC COMPARTMENT. THE MECHANISM OF NUCLEAR TRANSLOCATION OF DNMT1 IS GREATLY ENHANCED BY PHOSPHORYLATION OF THE DNMT1 NUCLEAR LOCALIZATION SIGNAL (NLS) BY PKB/AKT KINASE. MUTAGENIC ALTERATION OF THE TWO AKT TARGET AMINO ACIDS WITHIN THE NLS RESULTS IN A MAJOR LOSS OF DNMT1 NUCLEAR TRANSLOCATION, WHILE THE CREATION OF A "PHOSPHO-MIMIC" AMINO ACID (MUTATION TO ACIDIC RESIDUES) RESTORES THIS COMPARTMENTATION ABILITY. THESE OBSERVATIONS SUGGEST AN INTERESTING HYPOTHESIS REGARDING HOW MEDIATORS OF CHRONIC INFLAMMATION MAY DISTURB THE DELICATE BALANCE OF CELLULAR COMPARTMENTALIZATION OF IMPORTANT PROTEINS, AND REVEALS A POTENTIAL MECHANISM FOR THE INDUCTION OR ENHANCEMENT OF TUMOR GROWTH VIA ALTERATION OF THE COMPONENTS INVOLVED IN THE EPIGENETIC PROGRAMMING OF A CELL. 2007 10 3791 31 INTERLEUKIN 6 SUPPORTS THE MAINTENANCE OF P53 TUMOR SUPPRESSOR GENE PROMOTER METHYLATION. A STRONG ASSOCIATION EXISTS BETWEEN STATES OF CHRONIC INFLAMMATION AND CANCER, AND IT IS BELIEVED THAT MEDIATORS OF INFLAMMATION MAY BE RESPONSIBLE FOR THIS PHENOMENON. INTERLEUKIN 6 (IL-6) IS AN INFLAMMATORY CYTOKINE KNOWN TO PLAY A ROLE IN THE GROWTH AND SURVIVAL OF MANY TYPES OF TUMORS, YET THE MECHANISMS EMPLOYED BY THIS PLEOMORPHIC CYTOKINE TO ACCOMPLISH THIS FEAT ARE STILL POORLY UNDERSTOOD. ANOTHER IMPORTANT FACTOR IN TUMOR DEVELOPMENT SEEMS TO BE THE HYPERMETHYLATION OF CPG ISLANDS LOCATED WITHIN THE PROMOTER REGIONS OF TUMOR SUPPRESSOR GENES. THIS COMMON EPIGENETIC ALTERATION ENABLES TUMOR CELLS TO REDUCE OR INACTIVATE THE EXPRESSION OF IMPORTANT TUMOR SUPPRESSOR AND CELL CYCLE REGULATORY GENES. HERE WE SHOW THAT IN THE IL-6-RESPONSIVE HUMAN MULTIPLE MYELOMA CELL LINE KAS 6/1, THE PROMOTER REGION OF P53 IS EPIGENETICALLY MODIFIED BY METHYLTRANSFERASES, RESULTING IN DECREASED LEVELS OF EXPRESSION. FURTHERMORE, CELLS TREATED WITH IL-6 EXHIBIT AN INCREASE IN THE EXPRESSION OF THE DNA MAINTENANCE METHYLATION ENZYME, DNMT-1. THE DNA METHYLTRANSFERASE INHIBITOR ZEBULARINE REVERSES THE METHYLATION OF THE P53 PROMOTER, ALLOWING THE RESUMPTION OF ITS EXPRESSION. HOWEVER, WHEN ZEBULARINE IS WITHDRAWN FROM THE CELLS, THE REESTABLISHMENT OF THE ORIGINAL CPG ISLAND METHYLATION WITHIN THE P53 PROMOTER DOES NOT OCCUR IN THE ABSENCE OF IL-6, AND CELLS WHICH DO NOT RECEIVE IL-6 EVENTUALLY DIE, AS P53 EXPRESSION CONTINUES UNCHECKED BY REMETHYLATION. INTERESTINGLY, THIS LOSS OF VIABILITY SEEMS TO INVOLVE NOT THE WITHDRAWAL OF CYTOKINE, BUT THE INABILITY OF THE CELL TO RESILENCE THE PROMOTER. CONSISTENT WITH THIS MODEL, WHEN CELLS THAT EXPRESS IL-6 IN AN AUTOCRINE FASHION ARE SUBJECTED TO IDENTICAL TREATMENT, P53 EXPRESSION IS REDUCED SHORTLY AFTER WITHDRAWAL OF ZEBULARINE. THEREFORE, IT SEEMS IL-6 IS CAPABLE OF MAINTAINING PROMOTER METHYLATION THUS REPRESENTING ONE OF THE POSSIBLE MECHANISMS USED BY INFLAMMATORY MEDIATORS IN THE GROWTH AND SURVIVAL OF TUMORS. 2005 11 925 21 CHRONIC INFLAMMATION INDUCES A NOVEL EPIGENETIC PROGRAM THAT IS CONSERVED IN INTESTINAL ADENOMAS AND IN COLORECTAL CANCER. CHRONIC INFLAMMATION REPRESENTS A MAJOR RISK FACTOR FOR TUMOR FORMATION, BUT THE UNDERLYING MECHANISMS HAVE REMAINED LARGELY UNKNOWN. EPIGENETIC MECHANISMS CAN RECORD THE EFFECTS OF ENVIRONMENTAL CHALLENGES ON THE GENOME LEVEL AND COULD THEREFORE PLAY AN IMPORTANT ROLE IN THE PATHOGENESIS OF INFLAMMATION-ASSOCIATED TUMORS. USING SINGLE-BASE METHYLATION MAPS AND TRANSCRIPTOME ANALYSES OF A COLITIS-INDUCED MOUSE COLON CANCER MODEL, WE IDENTIFIED A NOVEL EPIGENETIC PROGRAM THAT IS CHARACTERIZED BY HYPERMETHYLATION OF DNA METHYLATION VALLEYS THAT ARE CHARACTERIZED BY LOW CPG DENSITY AND ACTIVE CHROMATIN MARKS. THIS PROGRAM IS CONSERVED AND FUNCTIONAL IN MOUSE INTESTINAL ADENOMAS AND RESULTS IN SILENCING OF ACTIVE INTESTINAL GENES THAT ARE INVOLVED IN GASTROINTESTINAL HOMEOSTASIS AND INJURY RESPONSE. FURTHER ANALYSES REVEAL THAT THE PROGRAM REPRESENTS A PROMINENT FEATURE OF HUMAN COLORECTAL CANCER AND CAN BE USED TO CORRECTLY CLASSIFY COLORECTAL CANCER SAMPLES WITH HIGH ACCURACY. TOGETHER, OUR RESULTS SHOW THAT INFLAMMATORY SIGNALS ESTABLISH A NOVEL EPIGENETIC PROGRAM THAT SILENCES A SPECIFIC SET OF GENES THAT CONTRIBUTE TO INFLAMMATION-INDUCED CELLULAR TRANSFORMATION. 2015 12 3658 25 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 13 2055 21 EPIGENETIC CONTROL DURING LYMPHOID DEVELOPMENT AND IMMUNE RESPONSES: ABERRANT REGULATION, VIRUSES, AND CANCER. METHYLATION OF CYTOSINES CONTROLS A NUMBER OF BIOLOGIC PROCESSES SUCH AS IMPRINTING AND X CHROMOSOMAL INACTIVATION. DNA HYPERMETHYLATION IS CLOSELY ASSOCIATED WITH TRANSCRIPTIONAL SILENCING, WHILE DNA HYPOMETHYLATION IS ASSOCIATED WITH TRANSCRIPTIONAL ACTIVATION. HYPOACETYLATION OF HISTONES LEADS TO COMPACT CHROMATIN WITH REDUCED ACCESSIBILITY TO THE TRANSCRIPTIONAL MACHINERY. METHYL-CPG BINDING PROTEINS CAN RECRUIT COREPRESSORS AND HISTONE DEACETYLASES; THUS, THE INTERPLAY BETWEEN THESE EPIGENETIC MECHANISMS REGULATES GENE ACTIVATION. METHYLATION HAS BEEN IMPLICATED AS AN IMPORTANT MECHANISM DURING IMMUNE DEVELOPMENT, CONTROLLING VDJ RECOMBINATION, LINEAGE-SPECIFIC EXPRESSION OF CELL SURFACE ANTIGENS, AND TRANSCRIPTIONAL REGULATION OF CYTOKINE GENES DURING IMMUNE RESPONSES. ABERRATIONS IN EPIGENETIC MACHINERY, EITHER BY GENETIC MUTATIONS OR BY SOMATIC CHANGES SUCH AS VIRAL INFECTIONS, ARE ASSOCIATED WITH EARLY ALTERATIONS IN CHRONIC DISEASES SUCH AS IMMUNODEFICIENCY AND CANCER. 2003 14 3795 26 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 15 4284 20 MICRORNA CIRCUITS REGULATE THE CANCER-INFLAMMATION LINK. GENETIC AND EPIGENETIC PERTURBATIONS ARE REQUIRED TO TRANSFORM NORMAL CELLS INTO CANCER CELLS. INFLAMMATORY SIGNALING PATHWAYS ARE ACTIVATED IN VARIOUS CANCERS, LINKING CHRONIC INFLAMMATION TO ONCOGENESIS. HOWEVER, THE MOLECULAR CIRCUITS THAT RESULT IN SUSTAINED ACTIVATION OF THESE INFLAMMATORY FACTORS ARE NOT YET WELL UNDERSTOOD. IN THE 28 JANUARY 2014 ISSUE OF SCIENCE SIGNALING, XIANG ET AL. IDENTIFIED A MICRORNA-MEDIATED ANTI-INFLAMMATORY CIRCUIT THAT IS REPRESSED EPIGENETICALLY IN RECEPTOR-NEGATIVE BREAST CANCERS. A HIGH-THROUGHPUT SCREEN FOR SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3)-REGULATED MICRORNAS REVEALED MICRORNA MIR-146B AS A DIRECT STAT3 TARGET IN MAMMARY EPITHELIAL CELLS, BUT DNA METHYLATION IN ITS PROMOTER AREA SUPPRESSED MIR-146B EXPRESSION IN CANCER CELLS. OVEREXPRESSION OF MIR-146B SUPPRESSED NUCLEAR FACTOR KAPPAB (NF-KAPPAB)-DEPENDENT EXPRESSION OF IL6 AND SUBSEQUENT STAT3 ACTIVATION AND DECREASED THE STAT3-INDUCED INVASIVENESS AND MESENCHYMAL PHENOTYPE OF BREAST CANCER CELLS. OVERALL, THIS STUDY CONTRIBUTES TO OUR UNDERSTANDING OF HOW INFLAMMATION IS INVOLVED IN ONCOGENIC TRANSFORMATION. FURTHER STUDIES COULD EVALUATE THE THERAPEUTIC POTENTIAL OF TARGETING THIS CIRCUIT IN ESTROGEN RECEPTOR-NEGATIVE BREAST CANCERS. 2014 16 3659 22 INDUCTION OF EPIGENETIC ALTERATIONS BY CHRONIC INFLAMMATION AND ITS SIGNIFICANCE ON CARCINOGENESIS. CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN DEVELOPMENT OF HUMAN CANCERS, SUCH AS GASTRIC AND LIVER CANCERS. INDUCTION OF CELL PROLIFERATION, PRODUCTION OF REACTIVE OXYGEN SPECIES, AND DIRECT STIMULATION OF EPITHELIAL CELLS BY INFLAMMATION-INDUCING FACTORS HAVE BEEN CONSIDERED AS MECHANISMS INVOLVED. INFLAMMATION-RELATED CANCERS ARE KNOWN FOR THEIR MULTIPLE OCCURRENCES, AND ABERRANT DNA METHYLATION IS KNOWN TO BE PRESENT EVEN IN NONCANCEROUS TISSUES. IMPORTANTLY, FOR SOME CANCERS, THE DEGREE OF ACCUMULATION HAS BEEN DEMONSTRATED TO BE CORRELATED WITH RISK OF DEVELOPING CANCERS. THIS INDICATES THAT INFLAMMATION INDUCES ABERRANT EPIGENETIC ALTERATIONS IN A TISSUE EARLY IN THE PROCESS OF CARCINOGENESIS, AND ACCUMULATION OF SUCH ALTERATIONS FORMS "AN EPIGENETIC FIELD FOR CANCERIZATION." THIS ALSO SUGGESTS THAT INHIBITION OF INDUCTION OF EPIGENETIC ALTERATIONS AND REMOVAL OF THE ACCUMULATED ALTERATIONS ARE NOVEL APPROACHES TO CANCER PREVENTION. DISTURBANCES IN CYTOKINE AND CHEMOKINE SIGNALS AND INDUCTION OF CELL PROLIFERATIONS ARE IMPORTANT MECHANISMS OF HOW INFLAMMATION INDUCES ABERRANT DNA METHYLATION. ABERRANT DNA METHYLATION IS INDUCED IN SPECIFIC GENES, AND GENE EXPRESSION LEVELS, THE PRESENCE OF RNA POLYMERASE II (ACTIVE OR STALLED), AND TRIMETHYLATION OF H3K4 ARE INVOLVED IN THE SPECIFICITY. EXPRESSION OF DNA METHYLTRANSFERASES (DNMTS) IS NOT NECESSARILY INDUCED BY INFLAMMATION, AND LOCAL IMBALANCE BETWEEN DNMTS AND FACTORS THAT PROTECT GENES FROM DNA METHYLATION SEEMS TO BE IMPORTANT. 2010 17 2493 31 EPIGENETICS AND CHROMATIN REMODELING PLAY A ROLE IN LUNG DISEASE. EPIGENETICS IS DEFINED AS HERITABLE CHANGES THAT AFFECT GENE EXPRESSION WITHOUT ALTERING THE DNA SEQUENCE. EPIGENETIC REGULATION OF GENE EXPRESSION IS FACILITATED THROUGH DIFFERENT MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND RNA-ASSOCIATED SILENCING BY SMALL NON-CODING RNAS. ALL THESE MECHANISMS ARE CRUCIAL FOR NORMAL DEVELOPMENT, DIFFERENTIATION AND TISSUE-SPECIFIC GENE EXPRESSION. THESE THREE SYSTEMS INTERACT AND STABILIZE ONE ANOTHER AND CAN INITIATE AND SUSTAIN EPIGENETIC SILENCING, THUS DETERMINING HERITABLE CHANGES IN GENE EXPRESSION. HISTONE ACETYLATION REGULATES DIVERSE CELLULAR FUNCTIONS INCLUDING INFLAMMATORY GENE EXPRESSION, DNA REPAIR AND CELL PROLIFERATION. TRANSCRIPTIONAL COACTIVATORS POSSESS INTRINSIC HISTONE ACETYLTRANSFERASE ACTIVITY AND THIS ACTIVITY DRIVES INFLAMMATORY GENE EXPRESSION. ELEVEN CLASSICAL HISTONE DEACETYLASES (HDACS) ACT TO REGULATE THE EXPRESSION OF DISTINCT SUBSETS OF INFLAMMATORY/IMMUNE GENES. THUS, LOSS OF HDAC ACTIVITY OR THE PRESENCE OF HDAC INHIBITORS CAN FURTHER ENHANCE INFLAMMATORY GENE EXPRESSION BY PRODUCING A GENE-SPECIFIC CHANGE IN HAT ACTIVITY. FOR EXAMPLE, HDAC2 EXPRESSION AND ACTIVITY ARE REDUCED IN LUNG MACROPHAGES, BIOPSY SPECIMENS, AND BLOOD CELLS FROM PATIENTS WITH SEVERE ASTHMA AND SMOKING ASTHMATICS, AS WELL AS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THIS MAY ACCOUNT, AT LEAST IN PART, FOR THE ENHANCED INFLAMMATION AND REDUCED STEROID RESPONSIVENESS SEEN IN THESE PATIENTS. OTHER PROTEINS, PARTICULARLY TRANSCRIPTION FACTORS, ARE ALSO ACETYLATED AND ARE TARGETS FOR DEACETYLATION BY HDACS AND SIRTUINS, A RELATED FAMILY OF 7 PREDOMINANTLY PROTEIN DEACETYLASES. THUS THE ACETYLATION/DEACETYLATION STATUS OF NF-KAPPAB AND THE GLUCOCORTICOID RECEPTOR CAN ALSO AFFECT THE OVERALL EXPRESSION PATTERN OF INFLAMMATORY GENES AND REGULATE THE INFLAMMATORY RESPONSE. UNDERSTANDING AND TARGETING SPECIFIC ENZYMES INVOLVED IN THIS PROCESS MIGHT LEAD TO NEW THERAPEUTIC AGENTS, PARTICULARLY IN SITUATIONS IN WHICH CURRENT ANTI-INFLAMMATORY THERAPIES ARE SUBOPTIMAL. 2011 18 4004 24 LOSS OF THE POLYCOMB MARK FROM BIVALENT PROMOTERS LEADS TO ACTIVATION OF CANCER-PROMOTING GENES IN COLORECTAL TUMORS. IN COLON TUMORS, THE TRANSCRIPTION OF MANY GENES BECOMES DEREGULATED BY POORLY DEFINED EPIGENETIC MECHANISMS THAT HAVE BEEN STUDIED MAINLY IN ESTABLISHED CELL LINES. IN THIS STUDY, WE USED FROZEN HUMAN COLON TISSUES TO ANALYZE PATTERNS OF HISTONE MODIFICATION AND DNA CYTOSINE METHYLATION IN CANCER AND MATCHED NORMAL MUCOSA SPECIMENS. DNA METHYLATION IS STRONGLY TARGETED TO BIVALENT H3K4ME3- AND H3K27ME3-ASSOCIATED PROMOTERS, WHICH LOSE BOTH HISTONE MARKS AND ACQUIRE DNA METHYLATION. HOWEVER, WE FOUND THAT LOSS OF THE POLYCOMB MARK H3K27ME3 FROM BIVALENT PROMOTERS WAS ACCOMPANIED OFTEN BY ACTIVATION OF GENES ASSOCIATED WITH CANCER PROGRESSION, INCLUDING NUMEROUS STEM CELL REGULATORS, ONCOGENES, AND PROLIFERATION-ASSOCIATED GENES. INDEED, WE FOUND MANY OF THESE SAME GENES WERE ALSO ACTIVATED IN PATIENTS WITH ULCERATIVE COLITIS WHERE CHRONIC INFLAMMATION PREDISPOSES THEM TO COLON CANCER. BASED ON OUR FINDINGS, WE PROPOSE THAT A LOSS OF POLYCOMB REPRESSION AT BIVALENT GENES COMBINED WITH AN ENSUING SELECTION FOR TUMOR-DRIVING EVENTS PLAYS A MAJOR ROLE IN CANCER PROGRESSION. 2014 19 3218 29 HELICOBACTER INFECTION IS REQUIRED FOR INFLAMMATION AND COLON CANCER IN SMAD3-DEFICIENT MICE. ACCUMULATING EVIDENCE SUGGESTS THAT INTESTINAL MICROBIAL ORGANISMS MAY PLAY AN IMPORTANT ROLE IN TRIGGERING AND SUSTAINING INFLAMMATION IN INDIVIDUALS AFFLICTED WITH INFLAMMATORY BOWEL DISEASE (IBD). MOREOVER, INDIVIDUALS WITH IBD ARE AT INCREASED RISK FOR DEVELOPING COLORECTAL CANCER, SUGGESTING THAT CHRONIC INFLAMMATION MAY INITIATE GENETIC OR EPIGENETIC CHANGES ASSOCIATED WITH CANCER DEVELOPMENT. WE TESTED THE HYPOTHESIS THAT BACTERIA MAY CONTRIBUTE TO THE DEVELOPMENT OF COLON CANCER BY SYNERGIZING WITH DEFECTIVE TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) SIGNALING, A PATHWAY COMMONLY MUTATED IN HUMAN COLON CANCER. ALTHOUGH OTHERS HAVE REPORTED THAT MICE DEFICIENT IN THE TGF-BETA SIGNALING MOLECULE SMAD3 DEVELOP COLON CANCER, WE FOUND THAT SMAD3-DEFICIENT MICE MAINTAINED FREE OF THE GRAM-NEGATIVE ENTEROHEPATIC BACTERIA HELICOBACTER SPP. FOR UP TO 9 MONTHS DO NOT DEVELOP COLON CANCER. FURTHERMORE, INFECTION OF SMAD3(-/-) MICE WITH HELICOBACTER TRIGGERS COLON CANCER IN 50% TO 66% OF THE ANIMALS. USING REAL-TIME PCR, WE FOUND THAT HELICOBACTER ORGANISMS CONCENTRATE IN THE CECUM, THE PREFERRED SITE OF TUMOR DEVELOPMENT. MUCINOUS ADENOCARCINOMAS DEVELOP 5 TO 30 WEEKS AFTER INFECTION AND ARE PRECEDED BY AN EARLY INFLAMMATORY PHASE, CONSISTING OF INCREASED PROLIFERATION OF EPITHELIAL CELLS; INCREASED NUMBERS OF CYCLOOXYGENASE-2-POSITIVE CELLS, CD4(+) T CELLS, MACROPHAGES; AND INCREASED MHC CLASS II EXPRESSION. COLONIC TISSUE REVEALED INCREASED TRANSCRIPTS FOR THE ONCOGENE C-MYC AND THE PROINFLAMMATORY CYTOKINES INTERLEUKIN-1ALPHA (IL-1ALPHA), IL-1BETA, IL-6, IFN-GAMMA, AND TUMOR NECROSIS FACTOR-ALPHA, SOME OF WHICH HAVE BEEN IMPLICATED IN COLON CANCER. THESE RESULTS SUGGEST THAT BACTERIA MAY BE IMPORTANT IN TRIGGERING COLORECTAL CANCER, NOTABLY IN THE CONTEXT OF GENE MUTATIONS IN THE TGF-BETA SIGNALING PATHWAY, ONE OF THE MOST COMMONLY AFFECTED CELLULAR PATHWAYS IN COLORECTAL CANCER IN HUMANS. 2006 20 6100 26 THE EMERGING ROLE OF EPIGENETIC MODIFIERS IN REPAIR OF DNA DAMAGE ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES. AT SITES OF CHRONIC INFLAMMATION EPITHELIAL CELLS ARE EXPOSED TO HIGH LEVELS OF REACTIVE OXYGEN SPECIES (ROS), WHICH CAN CONTRIBUTE TO THE INITIATION AND DEVELOPMENT OF MANY DIFFERENT HUMAN CANCERS. ABERRANT EPIGENETIC ALTERATIONS THAT CAUSE TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES ARE ALSO IMPLICATED IN MANY DISEASES ASSOCIATED WITH INFLAMMATION, INCLUDING CANCER. HOWEVER, IT IS NOT CLEAR HOW ALTERED EPIGENETIC GENE SILENCING IS INITIATED DURING CHRONIC INFLAMMATION. THE HIGH LEVEL OF ROS AT SITES OF INFLAMMATION IS KNOWN TO INDUCE OXIDATIVE DNA DAMAGE IN SURROUNDING EPITHELIAL CELLS. FURTHERMORE, DNA DAMAGE IS KNOWN TO TRIGGER SEVERAL RESPONSES, INCLUDING RECRUITMENT OF DNA REPAIR PROTEINS, TRANSCRIPTIONAL REPRESSION, CHROMATIN MODIFICATIONS AND OTHER CELL SIGNALING EVENTS. RECRUITMENT OF EPIGENETIC MODIFIERS TO CHROMATIN IN RESPONSE TO DNA DAMAGE RESULTS IN TRANSIENT COVALENT MODIFICATIONS TO CHROMATIN SUCH AS HISTONE UBIQUITINATION, ACETYLATION AND METHYLATION AND DNA METHYLATION. DNA DAMAGE ALSO ALTERS NON-CODING RNA EXPRESSION. ALL OF THESE ALTERATIONS HAVE THE POTENTIAL TO ALTER GENE EXPRESSION AT SITES OF DAMAGE. TYPICALLY, THESE MODIFICATIONS AND GENE TRANSCRIPTION ARE RESTORED BACK TO NORMAL ONCE THE REPAIR OF THE DNA DAMAGE IS COMPLETED. HOWEVER, CHRONIC INFLAMMATION MAY INDUCE SUSTAINED DNA DAMAGE AND DNA DAMAGE RESPONSES THAT RESULT IN THESE TRANSIENT COVALENT CHROMATIN MODIFICATIONS BECOMING MITOTICALLY STABLE EPIGENETIC ALTERATIONS. UNDERSTANDING HOW EPIGENETIC ALTERATIONS ARE INITIATED DURING CHRONIC INFLAMMATION WILL ALLOW US TO DEVELOP PHARMACEUTICAL STRATEGIES TO PREVENT OR TREAT CHRONIC INFLAMMATION-INDUCED CANCER. THIS REVIEW WILL FOCUS ON TYPES OF DNA DAMAGE AND EPIGENETIC ALTERATIONS ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES, THE TYPES OF DNA DAMAGE AND TRANSIENT COVALENT CHROMATIN MODIFICATIONS INDUCED BY INFLAMMATION AND OXIDATIVE DNA DAMAGE AND HOW THESE MODIFICATIONS MAY RESULT IN EPIGENETIC ALTERATIONS. 2019