1 6126 185 THE EPIGENETIC MODIFIER PBRM1 RESTRICTS THE BASAL ACTIVITY OF THE INNATE IMMUNE SYSTEM BY REPRESSING RETINOIC ACID-INDUCIBLE GENE-I-LIKE RECEPTOR SIGNALLING AND IS A POTENTIAL PROGNOSTIC BIOMARKER FOR COLON CANCER. IT HAS LONG BEEN KNOWN THAT PATIENTS SUFFERING FROM INFLAMMATORY BOWEL DISEASE (IBD) HAVE AN INCREASED RISK OF DEVELOPING COLORECTAL CANCER (CRC). THE INNATE IMMUNE SYSTEM OF HOST CELLS PROVIDES A FIRST-LINE DEFENCE AGAINST PATHOGENIC INFECTION, WHEREAS AN UNCONTROLLED INFLAMMATORY RESPONSE UNDER HOMEOSTATIC CONDITIONS USUALLY LEADS TO PATHOLOGICAL CONSEQUENCES, AS EXEMPLIFIED BY THE CHRONIC INFLAMMATION OF IBD. THE KEY MOLECULES AND PATHWAYS KEEPING INNATE IMMUNITY IN CHECK ARE STILL POORLY DEFINED. HERE, WE REPORT THAT THE CHROMATIN REMODELLER POLYBROMO-1 (PBRM1) IS A REPRESSOR OF INNATE IMMUNE SIGNALLING MEDIATED BY RETINOIC ACID-INDUCIBLE GENE-I (RIG-I)-LIKE RECEPTORS (RLRS). KNOCKDOWN OF PBRM1 IN COLON CANCER CELLS INCREASED THE EXPRESSION OF TWO RECEPTOR GENES (RIG-I AND MDA5) AND UPREGULATED INTERFERON (IFN)-RELATED AND INFLAMMATION-RELATED GENE SIGNATURES. THE INNATE IMMUNE SIGNAL STIMULATED BY A DOUBLE-STRANDED RNA VIRAL MIMIC WAS EXAGGERATED BY PBRM1 SUPPRESSION. PBRM1 COOPERATED WITH POLYCOMB PROTEIN EZH2 TO DIRECTLY BIND THE CIS-REGULATORY ELEMENTS OF RIG-I AND MDA5, THEREBY SUPPRESSING THEIR TRANSCRIPTION. MOREOVER, UPREGULATION OF RIG-I AND MDA5 IS REQUIRED FOR IFN RESPONSE ACTIVATION INDUCED BY PBRM1 SILENCING. TRIM25, A PROTEIN STIMULATED BY THE RLR PATHWAY AND IFN PRODUCTION, PHYSICALLY INTERACTED WITH PBRM1 AND INDUCED PBRM1 PROTEIN DESTABILIZATION BY PROMOTING ITS UBIQUITINATION. THESE FINDINGS REVEAL A PBRM1-RLR REGULATORY CIRCUIT THAT CAN KEEP INNATE IMMUNE ACTIVITY AT A MINIMAL LEVEL IN RESTING CELLS, AND ALSO ENSURE A ROBUST INFLAMMATORY RESPONSE IN THE CASE OF PATHOGEN INVASION. PBRM1 WAS FOUND TO BE DOWNREGULATED IN PRIMARY TISSUES FROM PATIENTS WITH CRC OR IBD, AND ITS EXPRESSION CORRELATED NEGATIVELY WITH THAT OF RLR GENES AND INTERFERON-STIMULATED GENES IN CRC SAMPLES. LOWER PBRM1 EXPRESSION WAS ASSOCIATED WITH ADVANCED PATHOLOGICAL GRADE AND POORER SURVIVAL OF CRC PATIENTS, INDICATING THAT PBRM1 COULD SERVE AS A POTENTIAL PROGNOSTIC BIOMARKER FOR CRC. COPYRIGHT (C) 2017 PATHOLOGICAL SOCIETY OF GREAT BRITAIN AND IRELAND. PUBLISHED BY JOHN WILEY & SONS, LTD. 2018 2 4284 33 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 3 4099 55 MBD2 ENABLES TUMOURIGENESIS WITHIN THE INTESTINE WHILE PREVENTING TUMOUR-PROMOTING INFLAMMATION. EPIGENETIC REGULATION PLAYS A KEY ROLE IN THE LINK BETWEEN INFLAMMATION AND CANCER. HERE WE EXAMINE MBD2, WHICH MEDIATES EPIGENETIC TRANSCRIPTIONAL SILENCING BY BINDING TO METHYLATED DNA. IN SEPARATE STUDIES THE MBD2(-/-) MOUSE HAS BEEN SHOWN (1) TO BE RESISTANT TO INTESTINAL TUMOURIGENESIS AND (2) TO HAVE AN ENHANCED INFLAMMATORY/IMMUNE RESPONSE, OBSERVATIONS THAT ARE INCONSISTENT WITH THE LINKS BETWEEN INFLAMMATION AND CANCER. TO CLARIFY ITS ROLE IN TUMOURIGENESIS AND INFLAMMATION, WE USED CONSTITUTIVE AND CONDITIONAL MODELS OF MBD2 DELETION TO EXPLORE ITS EPITHELIAL AND NON-EPITHELIAL ROLES IN THE INTESTINE. USING A CONDITIONAL MODEL, WE FOUND THAT SUPPRESSION OF INTESTINAL TUMOURIGENESIS IS DUE PRIMARILY TO THE ABSENCE OF MBD2 WITHIN THE EPITHELIA. NEXT, WE DEMONSTRATED, USING THE DSS COLITIS MODEL, THAT NON-EPITHELIAL ROLES OF MBD2 ARE KEY IN PREVENTING THE TRANSITION FROM ACUTE TO TUMOUR-PROMOTING CHRONIC INFLAMMATION. COMBINING MODELS REVEALED THAT PRIOR TO INFLAMMATION THE ALTERED MBD2(-/-) IMMUNE RESPONSE PLAYS A ROLE IN INTESTINAL TUMOUR SUPPRESSION. HOWEVER, FOLLOWING INFLAMMATION THE INTESTINE CONVERTS FROM TUMOUR SUPPRESSIVE TO TUMOUR PROMOTING. TO SUMMARISE, IN THE INTESTINE THE NORMAL FUNCTION OF MBD2 IS EXPLOITED BY CANCER CELLS TO ENABLE TUMOURIGENESIS, WHILE IN THE IMMUNE SYSTEM IT PLAYS A KEY ROLE IN PREVENTING TUMOUR-ENABLING INFLAMMATION. WHICH ROLE IS DOMINANT DEPENDS ON THE INFLAMMATION STATUS OF THE INTESTINE. AS ENVIRONMENTAL INTERACTIONS WITHIN THE INTESTINE CAN ALTER DNA METHYLATION PATTERNS, WE PROPOSE THAT MBD2 PLAYS A KEY ROLE IN DETERMINING WHETHER THESE INTERACTIONS ARE ANTI- OR PRO-TUMOURIGENIC AND THIS MAKES IT A USEFUL NEW EPIGENETIC MODEL FOR INFLAMMATION-ASSOCIATED CARCINOGENESIS. (C) 2018 THE AUTHORS. THE JOURNAL OF PATHOLOGY PUBLISHED BY JOHN WILEY & SONS LTD ON BEHALF OF PATHOLOGICAL SOCIETY OF GREAT BRITAIN AND IRELAND. 2018 4 5566 45 ROLE OF INFLAMMATION IN THE DEVELOPMENT OF COLORECTAL CANCER. CHRONIC INFLAMMATION CAN LEAD TO THE DEVELOPMENT OF MANY DISEASES, INCLUDING CANCER. INFLAMMATORY BOWEL DISEASE (IBD) THAT INCLUDES BOTH ULCERATIVE COLITIS (UC) AND CROHNMP'S DISEASE (CD) ARE RISK FACTORS FOR THE DEVELOPMENT OF COLORECTAL CANCER (CRC). MANY CYTOKINES PRODUCED PRIMARILY BY THE GUT IMMUNE CELLS EITHER DURING OR IN RESPONSE TO LOCALIZED INFLAMMATION IN THE COLON AND RECTUM ARE KNOWN TO STIMULATE THE COMPLEX INTERACTIONS BETWEEN THE DIFFERENT CELL TYPES IN THE GUT ENVIRONMENT RESULTING IN ACUTE INFLAMMATION. SUBSEQUENTLY, CHRONIC INFLAMMATION, TOGETHER WITH GENETIC AND EPIGENETIC CHANGES, HAVE BEEN SHOWN TO LEAD TO THE DEVELOPMENT AND PROGRESSION OF CRC. VARIOUS CELL TYPES PRESENT IN THE COLON, SUCH AS ENTEROCYTES, PANETH CELLS, GOBLET CELLS, AND MACROPHAGES, EXPRESS RECEPTORS FOR INFLAMMATORY CYTOKINES AND RESPOND TO TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA), INTERLEUKIN-1 BETA (IL-1BETA), IL-6, AND OTHER CYTOKINES. AMONG THE SEVERAL CYTOKINES PRODUCED, TNF-ALPHA AND IL-1BETA ARE THE KEY PRO-INFLAMMATORY MOLECULES THAT PLAY CRITICAL ROLES IN THE DEVELOPMENT OF CRC. THE CURRENT REVIEW IS INTENDED TO CONSOLIDATE THE PUBLISHED FINDINGS TO FOCUS ON THE ROLE OF PRO-INFLAMMATORY CYTOKINES, NAMELY TNF-ALPHA AND IL-1BETA, ON INFLAMMATION (AND THE ALTERED IMMUNE RESPONSE) IN THE GUT, TO BETTER UNDERSTAND THE DEVELOPMENT OF CRC IN IBD, USING VARIOUS EXPERIMENTAL MODEL SYSTEMS, PRECLINICAL AND CLINICAL STUDIES. MOREOVER, THIS REVIEW ALSO HIGHLIGHTS THE CURRENT THERAPEUTIC STRATEGIES AVAILABLE (MONOTHERAPY AND COMBINATION THERAPY) TO ALLEVIATE THE SYMPTOMS OR TREAT INFLAMMATION-ASSOCIATED CRC BY USING MONOCLONAL ANTIBODIES OR APTAMERS TO BLOCK PRO-INFLAMMATORY MOLECULES, INHIBITORS OF TYROSINE KINASES IN THE INFLAMMATORY SIGNALING CASCADE, COMPETITIVE INHIBITORS OF PRO-INFLAMMATORY MOLECULES, AND THE NUCLEIC ACID DRUGS LIKE SMALL ACTIVATING RNAS (SARNAS) OR MICRORNA (MIRNA) MIMICS TO ACTIVATE TUMOR SUPPRESSOR OR REPRESS ONCOGENE/PRO-INFLAMMATORY CYTOKINE GENE EXPRESSION. 2021 5 1479 33 DIVERSE TARGETS OF THE TRANSCRIPTION FACTOR STAT3 CONTRIBUTE TO T CELL PATHOGENICITY AND HOMEOSTASIS. STAT3, AN ESSENTIAL TRANSCRIPTION FACTOR WITH PLEIOTROPIC FUNCTIONS, PLAYS CRITICAL ROLES IN THE PATHOGENESIS OF AUTOIMMUNITY. DESPITE RECENT DATA LINKING STAT3 WITH INFLAMMATORY BOWEL DISEASE, EXACTLY HOW IT CONTRIBUTES TO CHRONIC INTESTINAL INFLAMMATION IS NOT KNOWN. USING A T CELL TRANSFER MODEL OF COLITIS, WE FOUND THAT STAT3 EXPRESSION IN T CELLS WAS ESSENTIAL FOR THE INDUCTION OF BOTH COLITIS AND SYSTEMIC INFLAMMATION. STAT3 WAS CRITICAL IN MODULATING THE BALANCE OF T HELPER 17 (TH17) AND REGULATORY T (TREG) CELLS, AS WELL AS IN PROMOTING CD4(+) T CELL PROLIFERATION. WE USED CHROMATIN IMMUNOPRECIPITATION AND MASSIVE PARALLEL SEQUENCING (CHIP-SEQ) TO DEFINE THE GENOME-WIDE TARGETS OF STAT3 IN CD4(+) T CELLS. WE FOUND THAT STAT3 BOUND TO MULTIPLE GENES INVOLVED IN TH17 CELL DIFFERENTIATION, CELL ACTIVATION, PROLIFERATION, AND SURVIVAL, REGULATING BOTH EXPRESSION AND EPIGENETIC MODIFICATIONS. THUS, STAT3 ORCHESTRATES MULTIPLE CRITICAL ASPECTS OF T CELL FUNCTION IN INFLAMMATION AND HOMEOSTASIS. 2010 6 4732 51 NOVEL BIOMARKERS FOR INFLAMMATORY BOWEL DISEASE AND COLORECTAL CANCER: AN INTERPLAY BETWEEN METABOLIC DYSREGULATION AND EXCESSIVE INFLAMMATION. PERSISTENT INFLAMMATION CAN TRIGGER ALTERED EPIGENETIC, INFLAMMATORY, AND BIOENERGETIC STATES. INFLAMMATORY BOWEL DISEASE (IBD) IS AN IDIOPATHIC DISEASE CHARACTERIZED BY CHRONIC INFLAMMATION OF THE GASTROINTESTINAL TRACT, WITH EVIDENCE OF SUBSEQUENT METABOLIC SYNDROME DISORDER. STUDIES HAVE DEMONSTRATED THAT AS MANY AS 42% OF PATIENTS WITH ULCERATIVE COLITIS (UC) WHO ARE FOUND TO HAVE HIGH-GRADE DYSPLASIA, EITHER ALREADY HAD COLORECTAL CANCER (CRC) OR DEVELOP IT WITHIN A SHORT TIME. THE PRESENCE OF LOW-GRADE DYSPLASIA IS ALSO PREDICTIVE OF CRC. MANY SIGNALING PATHWAYS ARE SHARED AMONG IBD AND CRC, INCLUDING CELL SURVIVAL, CELL PROLIFERATION, ANGIOGENESIS, AND INFLAMMATORY SIGNALING PATHWAYS. CURRENT IBD THERAPEUTICS TARGET A SMALL SUBSET OF MOLECULAR DRIVERS OF IBD, WITH MANY FOCUSED ON THE INFLAMMATORY ASPECT OF THE PATHWAYS. THUS, THERE IS A GREAT NEED TO IDENTIFY BIOMARKERS OF BOTH IBD AND CRC, THAT CAN BE PREDICTIVE OF THERAPEUTIC EFFICACY, DISEASE SEVERITY, AND PREDISPOSITION TO CRC. IN THIS STUDY, WE EXPLORED THE CHANGES IN BIOMARKERS SPECIFIC FOR INFLAMMATORY, METABOLIC, AND PROLIFERATIVE PATHWAYS, TO HELP DETERMINE THE RELEVANCE TO BOTH IBD AND CRC. OUR ANALYSIS DEMONSTRATED, FOR THE FIRST TIME IN IBD, THE LOSS OF THE TUMOR SUPPRESSOR PROTEIN RAS ASSOCIATED FAMILY PROTEIN 1A (RASSF1A), VIA EPIGENETIC CHANGES, THE HYPERACTIVATION OF THE OBLIGATE KINASE OF THE NOD2 PATHOGEN RECOGNITION RECEPTOR (RECEPTOR INTERACTING PROTEIN KINASE 2 [RIPK2]), THE LOSS OF ACTIVATION OF THE METABOLIC KINASE, AMP ACTIVATED PROTEIN KINASE (AMPKALPHA1), AND, LASTLY, THE ACTIVATION OF THE TRANSCRIPTION FACTOR AND KINASE YES ASSOCIATED PROTEIN (YAP) KINASE, THAT IS INVOLVED IN PROLIFERATION OF CELLS. THE EXPRESSION AND ACTIVATION STATUS OF THESE FOUR ELEMENTS ARE MIRRORED IN IBD, CRC, AND IBD-CRC PATIENTS AND, IMPORTANTLY, IN MATCHED BLOOD AND BIOPSY SAMPLES. THE LATTER WOULD SUGGEST THAT BIOMARKER ANALYSIS CAN BE PERFORMED NON-INVASIVELY, TO UNDERSTAND IBD AND CRC, WITHOUT THE NEED FOR INVASIVE AND COSTLY ENDOSCOPIC ANALYSIS. THIS STUDY, FOR THE FIRST TIME, ILLUSTRATES THE NEED TO UNDERSTAND IBD OR CRC BEYOND AN INFLAMMATORY PERSPECTIVE AND THE VALUE OF THERAPEUTICS DIRECTED TO RESET ALTERED PROLIFERATIVE AND METABOLIC STATES WITHIN THE COLON. THE USE OF SUCH THERAPEUTICS MAY TRULY DRIVE PATIENTS INTO REMISSION. 2023 7 925 35 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 8 2055 35 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 9 3218 45 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 10 6764 34 ZINC DEFICIENCY ENHANCED INFLAMMATORY RESPONSE BY INCREASING IMMUNE CELL ACTIVATION AND INDUCING IL6 PROMOTER DEMETHYLATION. SCOPE: ZINC DEFICIENCY RESULTS IN IMMUNE DYSFUNCTION AND PROMOTES SYSTEMIC INFLAMMATION. THE OBJECTIVE OF THIS STUDY WAS TO EXAMINE THE EFFECTS OF ZINC DEFICIENCY ON CELLULAR IMMUNE ACTIVATION AND EPIGENETIC MECHANISMS THAT PROMOTE INFLAMMATION. THIS WORK IS POTENTIALLY RELEVANT TO THE AGING POPULATION GIVEN THAT AGE-RELATED IMMUNE DEFECTS, INCLUDING CHRONIC INFLAMMATION, COINCIDE WITH DECLINING ZINC STATUS. METHODS AND RESULTS: AN IN VITRO CELL CULTURE SYSTEM AND THE AGED MOUSE MODEL WERE USED TO CHARACTERIZE IMMUNE ACTIVATION AND DNA METHYLATION PROFILES THAT MAY CONTRIBUTE TO THE ENHANCED PROINFLAMMATORY RESPONSE MEDIATED BY ZINC DEFICIENCY. ZINC DEFICIENCY UPREGULATED CELL ACTIVATION MARKERS ICAM1, MHC CLASS II, AND CD86 IN THP1 CELLS, WHICH COINCIDED WITH INCREASED IL1BETA AND IL6 RESPONSES FOLLOWING LPS STIMULATION. A DECREASED ZINC STATUS IN AGED MICE WAS SIMILARLY ASSOCIATED WITH INCREASED ICAM1 AND IL6 GENE EXPRESSION. REDUCED IL6 PROMOTER METHYLATION WAS OBSERVED IN ZINC-DEFICIENT THP1 CELLS, AS WELL AS IN AGED MICE AND HUMAN LYMPHOBLASTOID CELL LINES DERIVED FROM AGED INDIVIDUALS. CONCLUSION: ZINC DEFICIENCY INDUCED INFLAMMATORY RESPONSE IN PART BY ELICITING ABERRANT IMMUNE CELL ACTIVATION AND ALTERED PROMOTER METHYLATION. OUR RESULTS SUGGESTED POTENTIAL INTERACTIONS BETWEEN ZINC STATUS, EPIGENETICS, AND IMMUNE FUNCTION, AND HOW THEIR DYSREGULATION COULD CONTRIBUTE TO CHRONIC INFLAMMATION. 2015 11 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 12 3799 29 INTERPLAY BETWEEN INFLAMMATION AND EPIGENETIC CHANGES IN CANCER. IMMUNE RESPONSES CAN SUPPRESS TUMORIGENESIS, BUT ALSO CONTRIBUTE TO CANCER INITIATION AND PROGRESSION SUGGESTING A COMPLEX INTERACTION BETWEEN THE IMMUNE SYSTEM AND CANCER. EPIGENETIC ALTERATIONS, WHICH ARE HERITABLE CHANGES IN GENE EXPRESSION WITHOUT CHANGES TO THE DNA SEQUENCE, ALSO PLAY A ROLE IN CARCINOGENESIS THROUGH SILENCING EXPRESSION OF TUMOR SUPPRESSOR GENES AND ACTIVATING ONCOGENIC SIGNALING. INTERESTINGLY, EPITHELIAL CELLS AT SITES OF CHRONIC INFLAMMATION UNDERGO DNA METHYLATION ALTERATIONS THAT ARE SIMILAR TO THOSE PRESENT IN CANCER CELLS, SUGGESTING THAT INFLAMMATION MAY INITIATE CANCER-SPECIFIC EPIGENETIC CHANGES IN EPITHELIAL CELLS. FURTHERMORE, EPIGENETIC CHANGES OCCUR DURING IMMUNE CELL DIFFERENTIATION AND PARTICIPATE IN REGULATING THE IMMUNE RESPONSE, INCLUDING THE REGULATION OF INFLAMMATORY CYTOKINES. CANCER CELLS UTILIZE EPIGENETIC SILENCING OF IMMUNE-RELATED GENES TO EVADE THE IMMUNE RESPONSE. THIS CHAPTER WILL DETAIL THE INTERACTIONS BETWEEN INFLAMMATION AND EPIGENETICS IN TUMOR INITIATION, PROMOTION, AND IMMUNE EVASION AND HOW THESE CONNECTIONS ARE BEING LEVERAGED IN CANCER PREVENTION AND TREATMENT. 2016 13 2228 36 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 14 3791 40 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 15 5292 34 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 16 5872 36 SUSTAINED TNF-ALPHA STIMULATION LEADS TO TRANSCRIPTIONAL MEMORY THAT GREATLY ENHANCES SIGNAL SENSITIVITY AND ROBUSTNESS. TRANSCRIPTIONAL MEMORY ALLOWS CERTAIN GENES TO RESPOND TO PREVIOUSLY EXPERIENCED SIGNALS MORE ROBUSTLY. HOWEVER, WHETHER AND HOW THE KEY PROINFLAMMATORY CYTOKINE TNF-ALPHA MEDIATES TRANSCRIPTIONAL MEMORY ARE POORLY UNDERSTOOD. USING HEK293F CELLS AS A MODEL SYSTEM, WE REPORT THAT SUSTAINED TNF-ALPHA STIMULATION INDUCES TRANSCRIPTIONAL MEMORY DEPENDENT ON TET ENZYMES. THE HYPOMETHYLATED STATUS OF TRANSCRIPTIONAL REGULATORY REGIONS CAN BE INHERITED, FACILITATING NF-KAPPAB BINDING AND MORE ROBUST SUBSEQUENT ACTIVATION. A HIGH INITIAL METHYLATION LEVEL AND CPG DENSITY AROUND KAPPAB SITES ARE CORRELATED WITH THE FUNCTIONAL POTENTIAL OF TRANSCRIPTIONAL MEMORY MODULES. INTERESTINGLY, THE CALCB GENE, ENCODING THE PROVEN MIGRAINE THERAPEUTIC TARGET CGRP, EXHIBITS THE BEST TRANSCRIPTIONAL MEMORY. A NEIGHBORING PRIMATE-SPECIFIC ENDOGENOUS RETROVIRUS STIMULATES MORE RAPID, MORE STRONG, AND AT LEAST 100-FOLD MORE SENSITIVE CALCB INDUCTION IN SUBSEQUENT TNF-ALPHA STIMULATION. OUR STUDY REVEALS THAT TNF-ALPHA-MEDIATED TRANSCRIPTIONAL MEMORY IS GOVERNED BY ACTIVE DNA DEMETHYLATION AND GREATLY SENSITIZES MEMORY GENES TO MUCH LOWER DOSES OF INFLAMMATORY CUES. 2020 17 2036 30 EPIGENETIC CHANGES OF THE IMMUNE SYSTEM WITH ROLE IN TUMOR DEVELOPMENT. TUMOR DEVELOPMENT IS CLOSELY RELATED TO CHRONIC INFLAMMATION AND TO EVASION OF IMMUNE DEFENSE MECHANISMS BY NEOPLASTIC CELLS. THE MEDIATORS OF THE INFLAMMATORY PROCESS AS WELL AS PROTEINS INVOLVED IN IMMUNE RESPONSE OR IMMUNE RESPONSE EVASION CAN BE SUBJECT TO VARIOUS EPIGENETIC CHANGES SUCH AS METHYLATION, ACETYLATION, OR PHOSPHORYLATION. SOME OF THESE, SUCH AS CYTOKINE SUPPRESSORS, ARE UNDERGOING REPRESSION THROUGH EPIGENETIC CHANGES, AND OTHERS SUCH AS CYTOKINES OR CHEMOKINES ARE UNDERGOING ACTIVATION THROUGH EPIGENETIC CHANGES, BOTH MODIFICATIONS HAVING AS A RESULT TUMOR PROGRESSION. THE ACTIVATING CHANGES CAN AFFECT THE RECEPTOR MOLECULES INVOLVED IN IMMUNE RESPONSE AND THESE PROMOTE INFLAMMATION AND SUBSEQUENTLY TUMOR DEVELOPMENT WHILE THE INACTIVATING CHANGES SEEM TO BE RELATED TO THE TUMOR REGRESSION PROCESS. THE PROTEINS INVOLVED IN ANTIGEN PRESENTATION, AND, THEREFORE IN IMMUNE RESPONSE ESCAPE, SUCH AS CLASSICAL HLA PROTEINS AND RELATED APM (ANTIGEN PRESENTATION MACHINERY) WITH THEIR EPIGENETIC CHANGES CONTRIBUTE TO THE TUMOR DEVELOPMENT PROCESS, EITHER TO TUMOR PROGRESSION OR REGRESSION, DEPENDING ON THE IMMUNE EFFECTOR CELLS THAT ARE IN PLAY. 2018 18 2065 32 EPIGENETIC CONTROL OF INTESTINAL BARRIER FUNCTION AND INFLAMMATION IN ZEBRAFISH. THE INTESTINAL EPITHELIUM FORMS A BARRIER PROTECTING THE ORGANISM FROM MICROBES AND OTHER PROINFLAMMATORY STIMULI. THE INTEGRITY OF THIS BARRIER AND THE PROPER RESPONSE TO INFECTION REQUIRES PRECISE REGULATION OF POWERFUL IMMUNE HOMING SIGNALS SUCH AS TUMOR NECROSIS FACTOR (TNF). DYSREGULATION OF TNF LEADS TO INFLAMMATORY BOWEL DISEASES (IBD), BUT THE MECHANISM CONTROLLING THE EXPRESSION OF THIS POTENT CYTOKINE AND THE EVENTS THAT TRIGGER THE ONSET OF CHRONIC INFLAMMATION ARE UNKNOWN. HERE, WE SHOW THAT LOSS OF FUNCTION OF THE EPIGENETIC REGULATOR UBIQUITIN-LIKE PROTEIN CONTAINING PHD AND RING FINGER DOMAINS 1 (UHRF1) IN ZEBRAFISH LEADS TO A REDUCTION IN TNFA PROMOTER METHYLATION AND THE INDUCTION OF TNFA EXPRESSION IN INTESTINAL EPITHELIAL CELLS (IECS). THE INCREASE IN IEC TNFA LEVELS IS MICROBE-DEPENDENT AND RESULTS IN IEC SHEDDING AND APOPTOSIS, IMMUNE CELL RECRUITMENT, AND BARRIER DYSFUNCTION, CONSISTENT WITH CHRONIC INFLAMMATION. IMPORTANTLY, TNFA KNOCKDOWN IN UHRF1 MUTANTS RESTORES IEC MORPHOLOGY, REDUCES CELL SHEDDING, AND IMPROVES BARRIER FUNCTION. WE PROPOSE THAT LOSS OF EPIGENETIC REPRESSION AND TNF INDUCTION IN THE INTESTINAL EPITHELIUM CAN LEAD TO IBD ONSET. 2015 19 2233 42 EPIGENETIC MODIFICATIONS OF THE NUCLEAR FACTOR KAPPA B SIGNALLING PATHWAY AND ITS IMPACT ON INFLAMMATORY BOWEL DISEASE. BACKGROUND: INFLAMMATORY BOWEL DISEASE (IBD) IS A MULTIFACTORIAL CONDITION INFLUENCED BY THE IMMUNE SYSTEM, THE INTESTINAL MICROBIOTA, ENVIRONMENTAL FACTORS, GENETIC AND EPIGENETIC FACTORS. GENETIC- AND ENVIRONMENT- INDUCED DYSREGULATION OF THE NUCLEAR FACTOR-KAPPA B (NF-KAPPAB) TRANSCRIPTION FACTOR PATHWAY HAS BEEN LINKED TO IBD PATHOGENESIS. OBJECTIVE: TO ASSESS THE CURRENT EVIDENCE IN RELATION TO THE CONTRIBUTION OF THE CLASSICAL AND ALTERNATIVE NF-KAPPAB PATHWAYS IN IBD AND TO DISCUSS THE EPIGENETIC MECHANISMS THAT IMPACT ON NF-KAPPAB FUNCTION. METHODS: A MEDLINE SEARCH FOR 'NF-KAPPAB/NF-KAPPAB', IN COMBINATION WITH TERMS INCLUDING 'INFLAMMATORY BOWEL DISEASE/IBD', 'INTESTINAL INFLAMMATION', 'CROHN'S DISEASE', 'ULCERATIVE COLITIS', 'COLITIS'; 'EPIGENETICS', 'DNA METHYLATION', 'HISTONES', 'MICRORNAS/MIRNAS' AND 'SHORT NON-CODING/LONG NON-CODING RNAS' WAS PERFORMED. RESULTS: BOTH NF-KAPPAB PATHWAYS CONTRIBUTE TO THE CHRONIC INFLAMMATION UNDERLYING IBD BY REGULATING THE INFLAMMATORY IMMUNE RESPONSES AND HOMEOSTASIS OF THE INTESTINAL EPITHELIUM (CLASSICAL PATHWAY) OR REGULATING BOWEL INFLAMMATION AND EPITHELIAL MICROFOLD (M) CELL FUNCTION (ALTERNATIVE PATHWAY). DNA METHYLATION IS A COMMON EPIGENETIC MODIFICATION IN INTESTINAL INFLAMMATION, INCLUDING NFKB1 AND RELA LOCI. CONVERSELY, LITTLE IS UNDERSTOOD REGARDING EPIGENETIC EFFECTS ON GENES ENCODING OTHER NF-KAPPAB SUBUNITS, PARTICULARLY THOSE OF THE ALTERNATIVE PATHWAY, AND IN THE CONTEXT OF IBD. HOWEVER, NF-KAPPAB INTERACTION WITH CHROMATIN MODIFIERS IS ALSO SEEN TO BE AN ESSENTIAL MECHANISM OF REGULATION OF DOWNSTREAM TARGET GENES RELEVANT TO NF-KAPPAB-MEDIATED INFLAMMATORY RESPONSES. CONCLUSION: FURTHER RESEARCH IS CLEARLY WARRANTED IN THIS AREA, AS UNDERSTANDING THE CELL-SPECIFIC REGULATION OF THE NF-KAPPAB PATHWAYS WILL BRING RESEARCHERS INTO A POSITION TO ACHIEVE MORE EFFICIENT STRATIFICATION OF IBD PATIENTS, AND MORE TARGETED AND EFFECTIVE CHOICE OF TREATMENT. 2021 20 4951 33 PATHOGENESIS OF CHOLANGIOCARCINOMA: FROM GENETICS TO SIGNALLING PATHWAYS. CHOLANGIOCARCINOMA (CCA) IS A MALIGNANT TUMOUR OF BILE DUCT EPITHELIAL CELLS WITH DISMAL PROGNOSIS AND RISING INCIDENCE. CHRONIC INFLAMMATION RESULTING FROM LIVER FLUKE INFECTION, HEPATITIS AND OTHER INFLAMMATORY BOWEL DISEASES IS A MAJOR CONTRIBUTING FACTOR TO CHOLANGIOCARCINOGENESIS, LIKELY THROUGH ACCUMULATION OF SERIAL GENETIC AND EPIGENETIC ALTERATIONS RESULTING IN ABERRATION OF ONCOGENES AND TUMOUR SUPPRESSORS. RECENT STUDIES MAKING USE OF ADVANCES IN HIGH-THROUGHPUT GENOMICS HAVE REVEALED THE GENETIC LANDSCAPE OF CCA, GREATLY INCREASING OUR UNDERSTANDING OF ITS UNDERLYING BIOLOGY. A SERIES OF HIGHLY RECURRENT MUTATIONS IN GENES SUCH AS TP53, KRAS, SMAD4, BRAF, MLL3, ARID1A, PBRM1 AND BAP1, WHICH ARE KNOWN TO BE INVOLVED IN CELL CYCLE CONTROL, CELL SIGNALLING PATHWAYS AND CHROMATIN DYNAMICS, HAVE LED TO INVESTIGATIONS OF THEIR ROLES, THROUGH MOLECULAR TO MOUSE MODELLING STUDIES, IN CHOLANGIOCARCINOGENESIS. THIS REVIEW FOCUSES ON THE LANDSCAPE GENETIC ALTERATIONS IN CCA AND ITS FUNCTIONAL RELEVANCE TO THE FORMATION AND PROGRESSION OF CCA. 2015