1 188 177 ACETYL TRANSFERASE EP300 DEFICIENCY LEADS TO CHRONIC REPLICATION STRESS MEDIATED BY DEFECTIVE FORK PROTECTION AT STALLED REPLICATION FORKS. MUTATIONS IN THE EPIGENETIC REGULATOR AND GLOBAL TRANSCRIPTIONAL ACTIVATOR, E1A BINDING PROTEIN (EP300), IS BEING INCREASINGLY REPORTED IN AGGRESSIVE HEMATOLOGICAL MALIGNANCIES INCLUDING ADULT T-CELL LEUKEMIA/LYMPHOMA (ATLL). HOWEVER, THE MECHANISTIC CONTRIBUTION OF EP300 DYSREGULATION TO CANCER INITIATION AND PROGRESSION ARE CURRENTLY UNKNOWN. INDEPENDENT INHIBITION OF EP300 IN HUMAN CELLS RESULTS IN THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN REGULATING THE CELL CYCLE, DNA REPLICATION AND DNA DAMAGE RESPONSE. NEVERTHELESS, SPECIFIC FUNCTION PLAYED BY EP300 IN DNA REPLICATION INITIATION, PROGRESSION AND REPLICATION FORK INTEGRITY HAS NOT BEEN STUDIED. HERE, USING ATLL CELLS AS A MODEL TO STUDY EP300 DEFICIENCY AND AN P300-SELECTIVE PROTAC DEGRADER, DEGRADER AS A PHARMACOLOGIC TOOL, WE REVEAL THAT EP300-MUTATED CELLS DISPLAY PROLONGED CELL CYCLE KINETICS, DUE TO PRONOUNCED DYSREGULATIONS IN DNA REPLICATION DYNAMICS LEADING TO PERSISTENT GENOMIC INSTABILITY. ABERRANT DNA REPLICATION IN EP300-MUTATED CELLS IS CHARACTERIZED BY ELEVATED REPLICATION ORIGIN FIRING DUE TO INCREASED REPLISOME PAUSING GENOME-WIDE. WE DEMONSTRATE THAT EP300 DEFICIENCY RESULTS IN NUCLEOLYTIC DEGRADATION OF NASCENTLY SYNTHESIZED DNA AT STALLED FORKS DUE TO A PROMINENT DEFECT IN FORK STABILIZATION AND PROTECTION. THIS IN TURN RESULTS IN THE ACCUMULATION OF SINGLE STRANDED DNA GAPS AT COLLAPSED REPLICATION FORKS, IN EP300-DEFICIENT CELLS. INHIBITION OF MRE11 NUCLEASE RESCUES THE SSDNA ACCUMULATION INDICATING A DYSREGULATION IN DOWNSTREAM MECHANISMS THAT RESTRAIN NUCLEASE ACTIVITY AT STALLED FORKS. IMPORTANTLY, WE FIND THAT THE ABSENCE OF EP300 RESULTS IN DECREASED EXPRESSION OF BRCA2 PROTEIN EXPRESSION AND A DEPENDENCY ON POLD3-MEDIATED ERROR-PRONE REPLICATION RESTART MECHANISMS. THE OVERALL S-PHASE ABNORMALITIES OBSERVED LEAD TO UNDER-REPLICATED DNA IN G2/M THAT INSTIGATES MITOTIC DNA SYNTHESIS. THIS IN TURN IS ASSOCIATED WITH MITOTIC SEGREGATION DEFECTS CHARACTERIZED BY ELEVATED MICRONUCLEI FORMATION, ACCUMULATION OF CYTOSOLIC DNA AND TRANSMISSION OF UNREPAIRED INHERITED DNA LESIONS IN THE SUBSEQUENT G1-PHASE IN EP300-DEFICIENT CELLS. WE DEMONSTRATE THAT THE DNA REPLICATION DYNAMICS OF EP300-MUTATED CELLS ATLL CELLS RECAPITULATE FEATURES OF BRCA-DEFICIENT CANCERS. ALTOGETHER THESE RESULTS SUGGEST THAT MUTATIONS IN EP300 CAUSE CHRONIC DNA REPLICATION STRESS AND DEFECTIVE REPLICATION FORK RESTART RESULTS IN PERSISTENT GENOMIC INSTABILITY THAT UNDERLIE AGGRESSIVE CHEMO-RESISTANT TUMORIGENESIS IN HUMANS. 2023 2 3729 40 INHIBITION OF TET1 PREVENTS THE DEVELOPMENT OF OSTEOARTHRITIS AND REVEALS THE 5HMC LANDSCAPE THAT ORCHESTRATES PATHOGENESIS. OSTEOARTHRITIS (OA) IS A DEGENERATIVE DISEASE OF THE JOINT, WHICH RESULTS IN PAIN, LOSS OF MOBILITY, AND, EVENTUALLY, JOINT REPLACEMENT. CURRENTLY, NO DISEASE-MODIFYING DRUGS EXIST, PARTLY BECAUSE OF THE MULTIPLE LEVELS AT WHICH CARTILAGE HOMEOSTASIS IS DISRUPTED. RECENT STUDIES HAVE HIGHLIGHTED THE IMPORTANCE OF EPIGENETIC DYSREGULATION IN OA, SPARKING INTEREST IN THE EPIGENETIC MODULATION FOR THIS DISEASE. IN OUR PREVIOUS WORK, WE CHARACTERIZED A FIVEFOLD INCREASE IN CYTOSINE HYDROXYMETHYLATION (5HMC), AN OXIDIZED DERIVATIVE OF CYTOSINE METHYLATION (5MC) ASSOCIATED WITH GENE ACTIVATION, ACCUMULATING AT OA-ASSOCIATED GENES. TO TEST THE ROLE OF 5HMC IN OA, HERE, WE USED A MOUSE MODEL OF SURGICALLY INDUCED OA AND FOUND THAT OA ONSET WAS ACCOMPANIED BY A GAIN OF ~40,000 DIFFERENTIALLY HYDROXYMETHYLATED SITES BEFORE THE NOTABLE HISTOLOGICAL APPEARANCE OF DISEASE. WE DEMONSTRATED THAT TEN-ELEVEN-TRANSLOCATION ENZYME 1 (TET1) MEDIATES THE 5HMC DEPOSITION BECAUSE 98% OF SITES ENRICHED FOR 5HMC IN OA WERE LOST IN TET1(-/-) MICE. LOSS OF TET1-MEDIATED 5HMC PROTECTED THE TET1(-/-) MICE FROM OA DEVELOPMENT, INCLUDING DEGENERATION OF THE CARTILAGE SURFACE AND OSTEOPHYTE FORMATION, BY DIRECTLY PREVENTING THE ACTIVATION OF MULTIPLE OA PATHWAYS. LOSS OF TET1 IN HUMAN OA CHONDROCYTES REDUCED THE EXPRESSION OF THE MATRIX METALLOPROTEINASES MMP3 AND MMP13 AND MULTIPLE INFLAMMATORY CYTOKINES. INTRA-ARTICULAR INJECTIONS OF A DIOXYGENASES INHIBITOR, 2-HYDROXYGLUTARATE, ON MICE AFTER SURGICAL INDUCTION OF OA STALLED DISEASE PROGRESSION. TREATMENT OF HUMAN OA CHONDROCYTES WITH THE SAME INHIBITOR ALSO PHENOCOPIED TET1 LOSS. COLLECTIVELY, THESE DATA DEMONSTRATE THAT TET1-MEDIATED 5HMC DEPOSITION REGULATES MULTIPLE OA PATHWAYS AND CAN BE MODULATED FOR THERAPEUTIC INTERVENTION. 2020 3 372 24 AN EMERGING EPIDEMIC OF NONCOMMUNICABLE DISEASES IN DEVELOPING POPULATIONS DUE TO A TRIPLE EVOLUTIONARY MISMATCH. WITH THEIR TRANSITION FROM ADVERSE TO AFFLUENT ENVIRONMENTS, DEVELOPING POPULATIONS EXPERIENCE A RAPID INCREASE IN THE NUMBER OF INDIVIDUALS WITH NONCOMMUNICABLE DISEASES. HERE, WE EMPHASIZE THAT DEVELOPING POPULATIONS ARE MORE SUSCEPTIBLE THAN WESTERN POPULATIONS TO ACQUIRE THESE CHRONIC DISEASES, BECAUSE THEIR GENETIC, CULTURAL, AND EPIGENETIC CHARACTERISTICS DO NOT MATCH WITH THE EAGERLY AWAITED AFFLUENT ENVIRONMENTS. IN REGARD TO THIS, THERE IS AN URGENT NEED FOR PUBLIC HEALTH ORGANIZATIONS TO REORGANIZE CURRENT ENVIRONMENTS IN DEVELOPING POPULATIONS SO AS TO FIT THEIR INHERITED CHARACTERISTICS. UNFORTUNATELY, THIS NEED IS NEGLECTED AS AN ESSENTIAL PART OF THE SUSTAINABLE DEVELOPMENT GOALS THAT FORM THE CORE OF THE UNITED NATIONS' POST-2015 DEVELOPMENT AGENDA. ONLY THROUGH GLOBAL COLLABORATIVE EFFORTS CAN THE ENVIRONMENTS IN DEVELOPING POPULATIONS BE REORGANIZED AND, THEREBY, THE EMERGING EPIDEMIC OF NONCOMMUNICABLE DISEASES BE STALLED. 2016 4 3659 37 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 5 6590 40 TUMOR SUPPRESSOR INACTIVATION IN THE PATHOGENESIS OF ADULT T-CELL LEUKEMIA. TUMOR SUPPRESSOR FUNCTIONS ARE ESSENTIAL TO CONTROL CELLULAR PROLIFERATION, TO ACTIVATE THE APOPTOSIS OR SENESCENCE PATHWAY TO ELIMINATE UNWANTED CELLS, TO LINK DNA DAMAGE SIGNALS TO CELL CYCLE ARREST CHECKPOINTS, TO ACTIVATE APPROPRIATE DNA REPAIR PATHWAYS, AND TO PREVENT THE LOSS OF ADHESION TO INHIBIT INITIATION OF METASTASES. THEREFORE, TUMOR SUPPRESSOR GENES ARE INDISPENSABLE TO MAINTAINING GENETIC AND GENOMIC INTEGRITY. CONSEQUENTLY, INACTIVATION OF TUMOR SUPPRESSORS BY SOMATIC MUTATIONS OR EPIGENETIC MECHANISMS IS FREQUENTLY ASSOCIATED WITH TUMOR INITIATION AND DEVELOPMENT. IN CONTRAST, REACTIVATION OF TUMOR SUPPRESSOR FUNCTIONS CAN EFFECTIVELY REVERSE THE TRANSFORMED PHENOTYPE AND LEAD TO CELL CYCLE ARREST OR DEATH OF CANCEROUS CELLS AND BE USED AS A THERAPEUTIC STRATEGY. ADULT T-CELL LEUKEMIA/LYMPHOMA (ATLL) IS AN AGGRESSIVE LYMPHOPROLIFERATIVE DISEASE ASSOCIATED WITH INFECTION OF CD4 T CELLS BY THE HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 (HTLV-I). HTLV-I-ASSOCIATED T-CELL TRANSFORMATION IS THE RESULT OF A MULTISTEP ONCOGENIC PROCESS IN WHICH THE VIRUS INITIALLY INDUCES CHRONIC T-CELL PROLIFERATION AND ALTERS CELLULAR PATHWAYS RESULTING IN THE ACCUMULATION OF GENETIC DEFECTS AND THE DEREGULATED GROWTH OF VIRALLY INFECTED CELLS. THIS REVIEW WILL FOCUS ON THE CURRENT KNOWLEDGE OF THE GENETIC AND EPIGENETIC MECHANISMS REGULATING THE INACTIVATION OF TUMOR SUPPRESSORS IN THE PATHOGENESIS OF HTLV-I. 2015 6 4506 34 MRTF-A MEDIATES LPS-INDUCED PRO-INFLAMMATORY TRANSCRIPTION BY INTERACTING WITH THE COMPASS COMPLEX. CHRONIC INFLAMMATION UNDERSCORES THE PATHOGENESIS OF A RANGE OF HUMAN DISEASES. LIPOPOLYSACCHARIDE (LPS) ELICITS STRONG PRO-INFLAMMATORY RESPONSES IN MACROPHAGES THROUGH THE TRANSCRIPTION FACTOR NF-KAPPAB. THE EPIGENETIC MECHANISM UNDERLYING LPS-INDUCED PRO-INFLAMMATORY TRANSCRIPTION IS NOT FULLY UNDERSTOOD. HEREIN, WE DESCRIBE A ROLE FOR MYOCARDIN-RELATED TRANSCRIPTION FACTOR A (MRTF-A, ALSO KNOWN AS MKL1) IN THIS PROCESS. MRTF-A OVEREXPRESSION ENHANCED NF-KAPPAB-DEPENDENT PRO-INFLAMMATORY TRANSCRIPTION, WHEREAS MRTF-A SILENCING INHIBITED THIS PROCESS. MRTF-A DEFICIENCY ALSO REDUCED THE SYNTHESIS OF PRO-INFLAMMATORY MEDIATORS IN A MOUSE MODEL OF COLITIS. LPS PROMOTED THE RECRUITMENT OF MRTF-A TO THE PROMOTERS OF PRO-INFLAMMATORY GENES IN AN NF-KAPPAB-DEPENDENT MANNER. RECIPROCALLY, MRTF-A INFLUENCED THE NUCLEAR ENRICHMENT AND TARGET BINDING OF NF-KAPPAB. MECHANISTICALLY, MRTF-A WAS NECESSARY FOR THE ACCUMULATION OF ACTIVE HISTONE MODIFICATIONS ON NF-KAPPAB TARGET PROMOTERS BY COMMUNICATING WITH THE HISTONE H3K4 METHYLTRANSFERASE COMPLEX (COMPASS). SILENCING OF INDIVIDUAL MEMBERS OF COMPASS, INCLUDING ASH2, WDR5 AND SET1 (ALSO KNOWN AS SETD1A), DOWNREGULATED THE PRODUCTION OF PRO-INFLAMMATORY MEDIATORS AND IMPAIRED THE NF-KAPPAB KINETICS. IN SUMMARY, OUR WORK HAS UNCOVERED A PREVIOUSLY UNKNOWN FUNCTION FOR MRTF-A AND PROVIDED INSIGHTS INTO THE RATIONALIZED DEVELOPMENT OF ANTI-INFLAMMATORY THERAPEUTIC STRATEGIES. 2014 7 482 30 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 8 4374 33 MISMATCH REPAIR PROTEINS RECRUIT DNA METHYLTRANSFERASE 1 TO SITES OF OXIDATIVE DNA DAMAGE. AT SITES OF CHRONIC INFLAMMATION, EPITHELIAL CELLS ARE EXPOSED TO HIGH LEVELS OF REACTIVE OXYGEN SPECIES AND UNDERGO CANCER-ASSOCIATED DNA METHYLATION CHANGES, SUGGESTING THAT INFLAMMATION MAY INITIATE EPIGENETIC ALTERATIONS. PREVIOUSLY, WE DEMONSTRATED THAT OXIDATIVE DAMAGE CAUSES EPIGENETIC SILENCING PROTEINS TO BECOME PART OF A LARGE COMPLEX THAT IS LOCALIZED TO GC-RICH REGIONS OF THE GENOME, INCLUDING PROMOTER CPG ISLANDS THAT ARE EPIGENETICALLY SILENCED IN CANCER. HOWEVER, WHETHER THESE PROTEINS WERE RECRUITED DIRECTLY TO DAMAGED DNA OR DURING THE DNA REPAIR PROCESS WAS UNKNOWN. HERE WE DEMONSTRATE THAT THE MISMATCH REPAIR PROTEIN HETERODIMER MSH2-MSH6 PARTICIPATES IN THE OXIDATIVE DAMAGE-INDUCED RECRUITMENT OF DNA METHYLTRANSFERASE 1 (DNMT1) TO CHROMATIN. HYDROGEN PEROXIDE TREATMENT INDUCES THE INTERACTION OF MSH2-MSH6 WITH DNMT1, SUGGESTING THAT THE RECRUITMENT IS THROUGH A PROTEIN-PROTEIN INTERACTION. IMPORTANTLY, THE REDUCTION IN TRANSCRIPTION FOR GENES WITH CPG ISLAND-CONTAINING PROMOTERS CAUSED BY OXIDATIVE DAMAGE IS ABROGATED BY KNOCKDOWN OF MSH6 AND/OR DNMT1. OUR FINDINGS PROVIDE EVIDENCE THAT THE ROLE OF DNMT1 AT SITES OF OXIDATIVE DAMAGE IS TO REDUCE TRANSCRIPTION, POTENTIALLY PREVENTING TRANSCRIPTION FROM INTERFERING WITH THE REPAIR PROCESS. THIS STUDY UNIQUELY BRINGS TOGETHER SEVERAL FACTORS THAT ARE KNOWN TO CONTRIBUTE TO COLON CANCER, NAMELY INFLAMMATION, MISMATCH REPAIR PROTEINS, AND EPIGENETIC CHANGES. 2016 9 5973 29 TET-CATALYZED 5-HYDROXYMETHYLATION PRECEDES HNF4A PROMOTER CHOICE DURING DIFFERENTIATION OF BIPOTENT LIVER PROGENITORS. UNDERSTANDING THE PROCESSES THAT GOVERN LIVER PROGENITOR CELL DIFFERENTIATION HAS IMPORTANT IMPLICATIONS FOR THE DESIGN OF STRATEGIES TARGETING CHRONIC LIVER DISEASES, WHEREBY REGENERATION OF LIVER TISSUE IS CRITICAL. ALTHOUGH DNA METHYLATION (5MC) AND HYDROXYMETHYLATION (5HMC) ARE HIGHLY DYNAMIC DURING EARLY EMBRYONIC DEVELOPMENT, LESS IS KNOWN ABOUT THEIR ROLES AT LATER STAGES OF DIFFERENTIATION. USING AN IN VITRO MODEL OF HEPATOCYTE DIFFERENTIATION, WE SHOW HERE THAT 5HMC PRECEDES THE EXPRESSION OF PROMOTER 1 (P1)-DEPENDENT ISOFORMS OF HNF4A, A MASTER TRANSCRIPTION FACTOR OF HEPATOCYTE IDENTITY. 5HMC AND HNF4A EXPRESSION FROM P1 ARE DEPENDENT ON TEN-ELEVEN TRANSLOCATION (TET) DIOXYGENASES. IN TURN, THE LIVER PIONEER FACTOR FOXA2 IS NECESSARY FOR TET1 BINDING TO THE P1 LOCUS. BOTH FOXA2 AND TETS ARE REQUIRED FOR THE 5HMC-RELATED SWITCH IN HNF4A EXPRESSION. THE EPIGENETIC EVENT IDENTIFIED HERE MAY BE A KEY STEP FOR THE ESTABLISHMENT OF THE HEPATOCYTE PROGRAM BY HNF4A. 2017 10 3685 30 INFLAMMATION-ASSOCIATED CANCER DEVELOPMENT IN DIGESTIVE ORGANS: MECHANISMS AND ROLES FOR GENETIC AND EPIGENETIC MODULATION. CHRONIC INFLAMMATION, REGARDLESS OF INFECTIOUS AGENTS, PLAYS IMPORTANT ROLES IN THE DEVELOPMENT OF VARIOUS CANCERS, PARTICULARLY IN DIGESTIVE ORGANS, INCLUDING HELICOBACTER PYLORI-ASSOCIATED GASTRIC CANCER, HEPATITIS C VIRUS-POSITIVE HEPATOCELLULAR CARCINOMA, AND COLITIS-ASSOCIATED COLON CANCERS. CANCER DEVELOPMENT IS CHARACTERIZED BY STEPWISE ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS OF VARIOUS PROTO-ONCOGENES AND TUMOR-SUPPRESSOR GENES. DURING CHRONIC INFLAMMATION, INFECTIOUS AGENTS SUCH AS H PYLORI AND HEPATITIS C VIRUS AS WELL AS INTRINSIC MEDIATORS OF INFLAMMATORY RESPONSES, INCLUDING PROINFLAMMATORY CYTOKINES AND REACTIVE OXYGEN AND NITROGEN SPECIES, CAN INDUCE GENETIC AND EPIGENETIC CHANGES, INCLUDING POINT MUTATIONS, DELETIONS, DUPLICATIONS, RECOMBINATIONS, AND METHYLATION OF VARIOUS TUMOR-RELATED GENES THROUGH VARIOUS MECHANISMS. FURTHERMORE, INFLAMMATION ALSO MODULATES THE EXPRESSIONS OF MICRORNAS THAT INFLUENCE THE PRODUCTION OF SEVERAL TUMOR-RELATED MESSENGER RNAS OR PROTEINS. THESE MOLECULAR EVENTS INDUCED BY CHRONIC INFLAMMATION WORK IN CONCERT TO ALTER IMPORTANT PATHWAYS INVOLVED IN NORMAL CELLULAR FUNCTION, AND HENCE ACCELERATE INFLAMMATION-ASSOCIATED CANCER DEVELOPMENT. AMONG THESE, RECENT STUDIES HIGHLIGHTED AN IMPORTANT ROLE OF ACTIVATION-INDUCED CYTIDINE DEAMINASE, A NUCLEOTIDE-EDITING ENZYME ESSENTIAL FOR SOMATIC HYPERMUTATION AND CLASS-SWITCH RECOMBINATION OF THE IMMUNOGLOBULIN GENE, AS A GENOMIC MODULATOR IN INFLAMMATION-ASSOCIATED CANCER DEVELOPMENT. 2012 11 5492 32 REVIEW OF ARSENIC TOXICITY, SPECIATION AND POLYADENYLATION OF CANONICAL HISTONES. ARSENIC CONTAMINATION IMPACTS HUNDREDS OF MILLIONS OF PEOPLE IN THE WORLD. ARSENIC IS A WELL-ESTABLISHED HUMAN CARCINOGEN AND HAS BEEN SHOWN TO CAUSE SKIN, LUNG, BLADDER, LIVER, PROSTATE AND KIDNEY CANCERS, IN HUMANS. MECHANISMS THAT UNDERLIE ARSENIC-MEDIATED CARCINOGENESIS, INCLUDING EPIGENETIC ALTERATIONS, REMAIN LARGELY UNKNOWN. HUMAN EXPOSURE TO ARSENIC IS REVIEWED, AND THE MECHANISMS OF ITS ACUTE AND CHRONIC TOXICITY AND MECHANISMS OF ITS CARCINOGENESIS IN HUMANS ARE DISCUSSED. ARSENIC IS ONE OF THE FEW METALS THAT IS METABOLIZED IN VIVO, AND ARSENIC METHYLATION AND HOW THIS RESULTS IN A SHORTER HALF-LIFE IN VIVO ARE DISCUSSED. A REVIEW OF RECENT FINDINGS THAT ARSENIC CAUSES LOSS IN THE CELLULAR LEVELS OF STEM LOOP BINDING PROTEIN (SLBP) RESULTING IN POLYADENYLATION OF CANONICAL HISTONES (H3.1) AS A DEFAULT, INCREASING LEVELS OF H3.1 PROTEIN OUTSIDE OF S-PHASE. MALIGNANT CELL TRANSFORMATION IS INDUCED BY KNOCKDOWN OF SLBP AND BY OVEREXPRESSION OF POLYADENYLATED H3.1. ARSENIC INDUCED POLYADENYLATION OF H3.1 CAUSES ENHANCED LEVELS OF H3.1 PROTEIN DISPLACING H3.3 PROTEIN FROM ITS CELLULAR BINDING SITES, SINCE THE TWO PROTEINS DIFFER BY ONLY 5 AMINO ACIDS. KNOCKDOWN OF H3.3 ALONE CAN INDUCE CARCINOGENESIS, AND THEREFORE DISPLACEMENT OF FUNCTIONAL H3.3 PROTEIN BY INCREASED H3.1 PROTEIN, IS LIKELY A MECHANISM OF ARSENIC CARCINOGENESIS. 2019 12 2950 23 GENETIC AND EPIGENETIC DAMAGE INDUCED BY REACTIVE NITROGEN SPECIES: IMPLICATIONS IN CARCINOGENESIS. CHRONIC INFECTION AND INFLAMMATION ARE RECOGNIZED RISK FACTORS FOR HUMAN CANCER AT VARIOUS SITES. INFECTION AND INFLAMMATION CAN ACTIVATE AND INDUCE A VARIETY OF OXIDANT-GENERATING ENZYMES, INCLUDING NADPH OXIDASE AND INDUCIBLE NITRIC OXIDE SYNTHASE. REACTIVE OXYGEN AND NITROGEN SPECIES PRODUCED BY SUCH ENZYMES REACT WITH EACH OTHER TO GENERATE NEW AND MORE POTENT REACTIVE SPECIES. THESE OXIDANTS NOT ONLY CAN DAMAGE DNA AND INDUCE MUTATIONS, BUT ALSO CAN ACTIVATE ONCOGENE PRODUCTS AND/OR INACTIVATE TUMOR-SUPPRESSOR PROTEINS, THUS CONTRIBUTING TO MOST PROCESSES OF CARCINOGENESIS. APPROPRIATE TREATMENT OF INFLAMMATION SHOULD BE FURTHER EXPLORED FOR CHEMOPREVENTION OF HUMAN CANCERS, ESPECIALLY THOSE ASSOCIATED WITH CHRONIC INFLAMMATION. 2003 13 1945 31 EPIGALLOCATECHIN-3-GALLATE, A HISTONE ACETYLTRANSFERASE INHIBITOR, INHIBITS EBV-INDUCED B LYMPHOCYTE TRANSFORMATION VIA SUPPRESSION OF RELA ACETYLATION. BECAUSE THE P300/CBP-MEDIATED HYPERACETYLATION OF RELA (P65) IS CRITICAL FOR NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) ACTIVATION, THE ATTENUATION OF P65 ACETYLATION IS A POTENTIAL MOLECULAR TARGET FOR THE PREVENTION OF CHRONIC INFLAMMATION. DURING OUR ONGOING SCREENING STUDY TO IDENTIFY NATURAL COMPOUNDS WITH HISTONE ACETYLTRANSFERASE INHIBITOR (HATI) ACTIVITY, WE IDENTIFIED EPIGALLOCATECHIN-3-GALLATE (EGCG) AS A NOVEL HATI WITH GLOBAL SPECIFICITY FOR THE MAJORITY OF HAT ENZYMES BUT WITH NO ACTIVITY TOWARD EPIGENETIC ENZYMES INCLUDING HDAC, SIRT1, AND HMTASE. AT A DOSE OF 100 MICROMOL/L, EGCG ABROGATES P300-INDUCED P65 ACETYLATION IN VITRO AND IN VIVO, INCREASES THE LEVEL OF CYTOSOLIC IKAPPABALPHA, AND SUPPRESSES TUMOR NECROSIS FACTOR ALPHA (TNFALPHA)-INDUCED NF-KAPPAB ACTIVATION. WE ALSO SHOWED THAT EGCG PREVENTS TNFALPHA-INDUCED P65 TRANSLOCATION TO THE NUCLEUS, CONFIRMING THAT HYPERACETYLATION IS CRITICAL FOR NF-KAPPAB TRANSLOCATION AS WELL AS ACTIVITY. FURTHERMORE, EGCG TREATMENT INHIBITED THE ACETYLATION OF P65 AND THE EXPRESSION OF NF-KAPPAB TARGET GENES IN RESPONSE TO DIVERSE STIMULI. FINALLY, EGCG REDUCED THE BINDING OF P300 TO THE PROMOTER REGION OF INTERLEUKIN-6 GENE WITH AN INCREASED RECRUITMENT OF HDAC3, WHICH HIGHLIGHTS THE IMPORTANCE OF THE BALANCE BETWEEN HATS AND HISTONE DEACETYLASES IN THE NF-KAPPAB-MEDIATED INFLAMMATORY SIGNALING PATHWAY. IMPORTANTLY, EGCG AT 50 MICROMOL/L DOSE COMPLETELY BLOCKS EBV INFECTION-INDUCED CYTOKINE EXPRESSION AND SUBSEQUENTLY THE EBV-INDUCED B LYMPHOCYTE TRANSFORMATION. THESE RESULTS SHOW THE CRUCIAL ROLE OF ACETYLATION IN THE DEVELOPMENT OF INFLAMMATORY-RELATED DISEASES. 2009 14 2656 32 EPIMUTATION AND CANCER: A NEW CARCINOGENIC MECHANISM OF LYNCH SYNDROME (REVIEW). EPIMUTATION IS DEFINED AS ABNORMAL TRANSCRIPTIONAL REPRESSION OF ACTIVE GENES AND/OR ABNORMAL ACTIVATION OF USUALLY REPRESSED GENES CAUSED BY ERRORS IN EPIGENETIC GENE REPRESSION. EPIMUTATION ARISES IN SOMATIC CELLS AND THE GERMLINE, AND CONSTITUTIONAL EPIMUTATION MAY ALSO OCCUR. EPIMUTATION IS THE FIRST STEP OF TUMORIGENESIS AND CAN BE A DIRECT CAUSE OF CARCINOGENESIS. CANCERS ASSOCIATED WITH EPIMUTATION INCLUDE LYNCH SYNDROME (HEREDITARY NON-POLYPOSIS COLORECTAL CANCER, HNPCC), CHRONIC LYMPHOCYTIC LEUKEMIA, BREAST CANCER AND OVARIAN CANCER. EPIMUTATION HAS BEEN SHOWN FOR MANY TUMOR SUPPRESSOR GENES, INCLUDING RB, VHL, HMLH1, APC AND BRCA1, IN SPORADIC CANCERS. METHYLATION HAS RECENTLY BEEN SHOWN IN DNA FROM NORMAL TISSUES AND PERIPHERAL BLOOD IN CASES OF SPORADIC COLORECTAL CANCER AND MANY STUDIES SHOW CONSTITUTIVE EPIMUTATION IN CANCERS. EPIMUTATION OF DNA MISMATCH REPAIR (MMR) GENES (BRCA1, HMLH1 AND HMSH2) INVOLVED IN DEVELOPMENT FAMILIAL CANCERS HAS ALSO BEEN FOUND. THESE RESULTS HAVE LED TO A FOCUS ON EPIMUTATION AS A NOVEL ONCOGENIC MECHANISM. 2012 15 4114 34 MECHANISMS FOR THE INDUCTION OF GASTRIC CANCER BY HELICOBACTER PYLORI INFECTION: ABERRANT DNA METHYLATION PATHWAY. MULTIPLE PATHOGENIC MECHANISMS BY WHICH HELICOBACTER PYLORI INFECTION INDUCES GASTRIC CANCER HAVE BEEN ESTABLISHED IN THE LAST TWO DECADES. IN PARTICULAR, ABERRANT DNA METHYLATION IS INDUCED IN MULTIPLE DRIVER GENES, WHICH INACTIVATES THEM. METHYLATION PROFILES IN GASTRIC CANCER ARE ASSOCIATED WITH SPECIFIC SUBTYPES, SUCH AS MICROSATELLITE INSTABILITY. RECENT COMPREHENSIVE AND INTEGRATED ANALYSES SHOWED THAT MANY CANCER-RELATED PATHWAYS ARE MORE FREQUENTLY ALTERED BY ABERRANT DNA METHYLATION THAN BY MUTATIONS. ABERRANT DNA METHYLATION CAN EVEN BE PRESENT IN NONCANCEROUS GASTRIC MUCOSAE, PRODUCING AN "EPIGENETIC FIELD FOR CANCERIZATION." MECHANISTICALLY, H. PYLORI-INDUCED CHRONIC INFLAMMATION, BUT NOT H. PYLORI ITSELF, PLAYS A DIRECT ROLE IN THE INDUCTION OF ABERRANT DNA METHYLATION. THE EXPRESSION OF THREE INFLAMMATION-RELATED GENES, IL1B, NOS2, AND TNF, IS HIGHLY ASSOCIATED WITH THE INDUCTION OF ABERRANT DNA METHYLATION. IMPORTANTLY, THE DEGREE OF ACCUMULATED ABERRANT DNA METHYLATION IS STRONGLY CORRELATED WITH GASTRIC CANCER RISK. A RECENT MULTICENTER PROSPECTIVE COHORT STUDY DEMONSTRATED THE UTILITY OF EPIGENETIC CANCER RISK DIAGNOSIS FOR METACHRONOUS GASTRIC CANCER. SUPPRESSION OF ABERRANT DNA METHYLATION BY A DEMETHYLATING AGENT WAS SHOWN TO INHIBIT GASTRIC CANCER DEVELOPMENT IN AN ANIMAL MODEL. INDUCTION OF ABERRANT DNA METHYLATION IS THE MAJOR PATHWAY BY WHICH H. PYLORI INFECTION INDUCES GASTRIC CANCER, AND THIS CAN BE UTILIZED FOR TRANSLATIONAL OPPORTUNITIES. 2017 16 4044 25 MACROPHAGES IN OXIDATIVE STRESS AND MODELS TO EVALUATE THE ANTIOXIDANT FUNCTION OF DIETARY NATURAL COMPOUNDS. ANTIOXIDANT TESTING OF NATURAL PRODUCTS HAS ATTRACTED INCREASING INTEREST IN RECENT YEARS, MAINLY DUE TO THE FACT THAT AN ANTIOXIDANT-RICH DIET MIGHT PROVIDE HEALTH BENEFITS. ACTIVATED MACROPHAGES ARE A MAJOR SOURCE OF REACTIVE OXYGEN SPECIES, REACTIVE NITROGEN SPECIES, AND PEROXYNITRITE GENERATED THROUGH THE SO-CALLED RESPIRATORY BURST. CONSTITUTIVELY RELEASED PROINFLAMMATORY CYTOKINE, ESPECIALLY TUMOR NECROSIS FACTOR-ALPHA, TRIGGERS NUCLEAR FACTOR-KAPPAB, AND ACTIVATOR PROTEIN-1 TRANSLOCATION LEADING TO THE OVER PRODUCTION OF REACTIVE OXYGEN SPECIES AND REACTIVE NITROGEN SPECIES IN MACROPHAGES. ACTIVATION OF TRANSCRIPTION FACTORS IN THE LONG-LIVED TISSUE-RESIDENT MACROPHAGES AND/OR MONOCYTE-DERIVED MACROPHAGES, TRIGGER EPIGENETIC MODIFICATIONS LEADING TO THE PATHOGENESIS OF CHRONIC DISEASES. NUTRACEUTICALS INCLUDING LIPID RAFT STRUCTURE DISRUPTION AGENT, CHOLESTEROL DEPLETION AGENT, FARNESYLTRANSFERASE INHIBITOR, NUCLEAR FACTOR-KAPPAB BLOCKER (ALPHA,BETA-UNSATURATED CARBONYL COMPOUNDS), GLUCOCORTICOID RECEPTOR AGONIST, AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AGONIST HAVE LONG BEEN USED TO INACTIVE MACROPHAGE. THE INHIBITION EFFECTS ON THE FORMATION OF NITRIC OXIDE, SUPEROXIDE, AND NITRITE PEROXIDE MAY BE RESPONSIBLE FOR THE ANTI-INFLAMMATORY FUNCTIONALITIES. ACTIVATED MACROPHAGE MODELS COULD BE USED TO IDENTIFY THE ACTIVE COMPONENTS FOR FUNCTIONAL DIETS DEVELOPMENT THROUGH A MULTIPLE TARGETS STRATEGY. 2017 17 6841 33 [MECHANISMS OF H. PYLORI INFECTION-INDUCED GASTRIC CARCINOGENESIS]. MANY EPIDEMIOLOGICAL STUDIES HAVE DEMONSTRATED A STRONG ASSOCIATION BETWEEN H. PYLORI (HELICOBACTER PYLORI) INFECTION AND HUMAN GASTRIC CANCER DEVELOPMENT. THE PRECISE MECHANISMS ACCOUNTING FOR GASTRIC CANCER DEVELOPMENT INDUCED BY H. PYLORI INFECTION ARE STILL NOT COMPLETELY UNDERSTOOD. HOWEVER, IT SHOULD BE REASONABLE TO ASSUME THAT THERE ARE TWO DISTINCT MOLECULAR PATHWAYS FOR GASTRIC CARCINOGENESIS BY H. PYLORI INFECTION; THE DIRECT ACTION OF THE BACTERIA ITSELF ON GASTRIC EPITHELIAL CELLS, AND THE ACCUMULATION OF GENETIC CHANGES CAUSED BY PROLONGED BACTERIAL INFECTION AND CHRONIC INFLAMMATION. AS A DIRECT ACTION OF H. PYLORI, BACTERIAL PROTEINS SUCH AS CAGA COULD BE DELIVERED INTO GASTRIC EPITHELIAL CELLS VIA THE TYPE IV SECRETION APPARATUS AND MODIFY THE HOST CELL FUNCTIONS RELATED TO CELL PROLIFERATION. IN ADDITION TO THE DIRECT BACTERIAL ACTION, H. PYLORI INFECTION AND THE RESULTANT INFLAMMATORY RESPONSE CAUSE VARIOUS GENETIC AND EPIGENETIC CHANGES IN TUMOR-RELATED GENES OF THE GASTRIC EPITHELIAL CELLS. NOTABLY, EXPRESSION OF AID (ACTIVATION-INDUCED CYTIDINE DEAMINASE), A DNA EDITING ENZYME THAT UNDERGOES SOMATIC HYPERMUTATION ON HUMAN GENES, IS INDUCED IN RESPONSE TO H. PYLORI INFECTION AND PROINFLAMMATORY CYTOKINE STIMULATION IN HUMAN GASTRIC EPITHELIAL CELLS. AS A RESULT, THE ACCUMULATION OF GENETIC ALTERATIONS WOULD PERSIST UNTIL THE CLINICAL STAGE OF ATROPHIC GASTRITIS AND EVENTUALLY TRIGGER THE MALIGNANT TRANSFORMATION OF GASTRIC CELLS. 2010 18 3224 34 HELICOBACTER PYLORI INFECTION AND STEM CELLS AT THE ORIGIN OF GASTRIC CANCER. HELICOBACTER PYLORI INFECTION IS NOW RECOGNIZED AS THE MAIN AND SPECIFIC INFECTIOUS CAUSE OF CANCER IN THE WORLD. IT IS RESPONSIBLE FOR GASTRIC ADENOCARCINOMAS OF BOTH INTESTINAL AND DIFFUSE TYPES, WHICH ARE THE LONG-TERM CONSEQUENCES OF THE CHRONIC INFECTION OF THE GASTRIC MUCOSA. CASE-CONTROL STUDIES HAVE SHOWN AN ASSOCIATION BETWEEN THE TWO, RECOGNIZED AS EARLY AS 1994 AND FURTHER SUBSTANTIATED BY INTERVENTIONAL STUDIES IN WHICH H. PYLORI ERADICATION HAS LED TO THE PREVENTION OF AT LEAST PART OF THE GASTRIC CANCERS. EXPERIMENTAL STUDIES HAVE HIGHLIGHTED THE ROLE OF BONE MARROW-DERIVED CELLS (BMDCS) AND PARTICULARLY MESENCHYMAL STEM CELLS, IN THE NEOPLASTIC PROCESS IN ABOUT A QUARTER OF THE CASES AND POSSIBLY AN EPITHELIAL-MESENCHYMAL TRANSITION (EMT) IN THE OTHER CASES. DIFFERENT STUDIES HAVE CONFIRMED THAT CHRONIC INFECTION WITH H. PYLORI INDUCES A CHRONIC INFLAMMATION AND SUBSEQUENT DAMAGE OF THE GASTRIC EPITHELIAL MUCOSA, LEADING TO BMDC RECRUITMENT. ONCE RECRUITED, THESE CELLS HOME AND DIFFERENTIATE BY CELL-CELL FUSION WITH LOCAL GASTRIC EPITHELIAL CELLS, BEARING LOCAL STEM CELL FAILURE AND PARTICIPATING IN TISSUE REGENERATION. THE CONTEXT OF CHRONIC INFECTION AND INFLAMMATION LEADS TO AN EMT AND ALTERED TISSUE REGENERATION AND DIFFERENTIATION FROM BOTH LOCAL EPITHELIAL STEM CELLS AND BMDC. EMT INDUCES THE EMERGENCE OF CD44+ CELLS POSSESSING MESENCHYMAL AND STEM CELL PROPERTIES, RESULTING IN METAPLASTIC AND DYSPLASTIC LESIONS TO GIVE RISE, AFTER ADDITIONAL EPIGENETIC AND MUTATIONAL EVENTS, TO THE EMERGENCE OF CANCER STEM CELLS (CSCS) AND ADENOCARCINOMA. 2015 19 2334 31 EPIGENETIC REGULATION OF INFLAMMATORY CYTOKINE-INDUCED EPITHELIAL-TO-MESENCHYMAL CELL TRANSITION AND CANCER STEM CELL GENERATION. THE NEOPLASTIC TRANSFORMATION OF NORMAL TO METASTATIC CANCER CELLS IS A COMPLEX MULTISTEP PROCESS INVOLVING THE PROGRESSIVE ACCUMULATION OF INTERACTING GENETIC AND EPIGENETIC CHANGES THAT ALTER GENE FUNCTION AND AFFECT CELL PHYSIOLOGY AND HOMEOSTASIS. EPIGENETIC CHANGES INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND CHANGES IN NONCODING RNA EXPRESSION, AND DEREGULATION OF EPIGENETIC PROCESSES CAN ALTER GENE EXPRESSION DURING THE MULTISTEP PROCESS OF CARCINOGENESIS. CANCER PROGRESSION AND METASTASIS THROUGH AN 'INVASION-METASTASIS CASCADE' INVOLVING AN EPITHELIAL-TO-MESENCHYMAL CELL TRANSITION (EMT), THE GENERATION OF CANCER STEM CELLS (CSCS), INVASION OF ADJACENT TISSUES, AND DISSEMINATION ARE FUELED BY INFLAMMATION, WHICH IS CONSIDERED A HALLMARK OF CANCER. CHRONIC INFLAMMATION IS GENERATED BY INFLAMMATORY CYTOKINES SECRETED BY THE TUMOR AND THE TUMOR-ASSOCIATED CELLS WITHIN THE TUMOR MICROENVIRONMENT. INFLAMMATORY CYTOKINE SIGNALING INITIATES SIGNALING PATHWAYS LEADING TO THE ACTIVATION OF MASTER TRANSCRIPTION FACTORS (TFS) SUCH AS SMADS, STAT3, AND NF-KAPPAB. MOREOVER, THE SAME INFLAMMATORY RESPONSES ALSO ACTIVATE EMT-INDUCING TF (EMT-TF) FAMILIES SUCH AS SNAIL, TWIST, AND ZEB, AND EPIGENETIC REGULATORS INCLUDING DNA AND HISTONE MODIFYING ENZYMES AND MICORNAS, THROUGH COMPLEX INTERCONNECTED POSITIVE AND NEGATIVE FEEDBACK LOOPS TO REGULATE EMT AND CSC GENERATION. HERE, WE REVIEW THE MOLECULAR REGULATORY FEEDBACK LOOPS AND NETWORKS INVOLVED IN INFLAMMATORY CYTOKINE-INDUCED EMT AND CSC GENERATION. 2019 20 6201 30 THE INFLAMMATORY MICROENVIRONMENT AND MICROBIOME IN PROSTATE CANCER DEVELOPMENT. CHRONIC INFLAMMATION PROMOTES THE DEVELOPMENT OF SEVERAL TYPES OF SOLID CANCERS AND MIGHT CONTRIBUTE TO PROSTATE CARCINOGENESIS. THIS HYPOTHESIS PARTLY ORIGINATES IN THE FREQUENT OBSERVATION OF INFLAMMATORY CELLS IN THE PROSTATE MICROENVIRONMENT OF ADULT MEN. INFLAMMATION IS ASSOCIATED WITH PUTATIVE PROSTATE CANCER PRECURSOR LESIONS, TERMED PROLIFERATIVE INFLAMMATORY ATROPHY. INFLAMMATION MIGHT DRIVE PROSTATE CARCINOGENESIS VIA OXIDATIVE STRESS AND GENERATION OF REACTIVE OXYGEN SPECIES THAT INDUCE MUTAGENESIS. ADDITIONALLY, INFLAMMATORY STRESS MIGHT CAUSE EPIGENETIC ALTERATIONS THAT PROMOTE NEOPLASTIC TRANSFORMATION. PROLIFERATIVE INFLAMMATORY ATROPHY IS ENRICHED FOR PROLIFERATIVE LUMINAL EPITHELIAL CELLS OF INTERMEDIATE PHENOTYPE THAT MIGHT BE PRONE TO GENOMIC ALTERATIONS LEADING TO PROSTATIC INTRAEPITHELIAL NEOPLASIA AND PROSTATE CANCER. STUDIES IN ANIMALS SUGGEST THAT INFLAMMATORY CHANGES IN THE PROSTATE MICROENVIRONMENT CONTRIBUTE TO REPROGRAMMING OF PROSTATE EPITHELIAL CELLS, A POSSIBLE STEP IN TUMOUR INITIATION. PROSTATIC INFECTION, CONCURRENT WITH EPITHELIAL BARRIER DISRUPTION, MIGHT BE A KEY DRIVER OF AN INFLAMMATORY MICROENVIRONMENT; THE DISCOVERY OF A URINARY MICROBIOME INDICATES A POTENTIAL SOURCE OF FREQUENT EXPOSURE OF THE PROSTATE TO A DIVERSE NUMBER OF MICROORGANISMS. HENCE, CURRENT EVIDENCE SUGGESTS THAT INFLAMMATION AND ATROPHY ARE INVOLVED IN PROSTATE CARCINOGENESIS AND SUGGESTS A ROLE FOR THE MICROBIOME IN ESTABLISHING AN INFLAMMATORY PROSTATE MICROENVIRONMENT THAT MIGHT PROMOTE PROSTATE CANCER DEVELOPMENT AND PROGRESSION. 2018