1 3645 133 INCREASED PRESENCE AND DIFFERENTIAL MOLECULAR IMPRINTING OF TRANSIT AMPLIFYING CELLS IN PSORIASIS. PSORIASIS IS A VERY COMMON CHRONIC INFLAMMATORY SKIN DISEASE CHARACTERIZED BY EPIDERMAL THICKENING AND SCALING RESULTING FROM KERATINOCYTE HYPERPROLIFERATION AND IMPAIRED DIFFERENTIATION. PATHOMECHANISTIC STUDIES IN PSORIASIS ARE OFTEN LIMITED BY USING WHOLE SKIN TISSUE BIOPSIES, NEGLECTING THEIR STRATIFICATION AND CELLULAR DIVERSITY. THIS STUDY AIMED AT CHARACTERIZING EPIDERMAL ALTERATIONS IN PSORIASIS AT THE LEVEL OF KERATINOCYTE POPULATIONS. EPIDERMAL CELL POPULATIONS WERE PURIFIED FROM SKIN BIOPSIES OF PSORIASIS PATIENTS AND HEALTHY DONORS USING A NOVEL CELL TYPE-SPECIFIC APPROACH. MOLECULAR CHARACTERIZATION OF THE TRANSIT-AMPLIFYING CELLS (TAC), THE KEY PLAYERS OF EPIDERMAL RENEWAL, WAS PERFORMED USING IMMUNOCYTOFLUORESCENCE-TECHNIQUE AND INTEGRATED MULTISCALE-OMICS ANALYSES. ALREADY TAC FROM NON-LESIONAL PSORIATIC SKIN SHOWED ALTERED METHYLATION AND DIFFERENTIAL EXPRESSION IN 1.7% AND 1.0% OF ALL PROTEIN-CODING GENES, RESPECTIVELY. IN PSORIATIC LESIONS, TAC WERE STRONGLY EXPANDED SHOWING FURTHER INCREASED DIFFERENTIALLY METHYLATED (10-FOLD) AND EXPRESSED (22-FOLD) GENES NUMBERS. IMPORTANTLY, 17.2% OF DIFFERENTIALLY EXPRESSED GENES WERE ASSOCIATED WITH RESPECTIVE GENE METHYLATIONS. COMPARED WITH NON-LESIONAL TAC, PATHWAY ANALYSES REVEALED METABOLIC ALTERATIONS AS ONE FEATURE PREDOMINANTLY CHANGED IN TAC DERIVED FROM ACTIVE PSORIATIC LESIONS. OVERALL, OUR STUDY SHOWED STAGE-SPECIFIC MOLECULAR ALTERATIONS, ALLOWS NEW INSIGHTS INTO THE PATHOGENESIS, AND IMPLIES THE INVOLVEMENT OF EPIGENETIC MECHANISMS IN LESION DEVELOPMENT IN PSORIASIS. KEY MESSAGES: TRANSIT AMPLIFYING CELL (TAC) NUMBERS ARE HIGHLY INCREASED IN PSORIATIC LESIONS PSORIATIC TAC SHOW PROFOUND MOLECULAR ALTERATIONS & STAGE-SPECIFIC IDENTITY TAC FROM UNAFFECTED AREAS ALREADY SHOW FIRST SIGNS OF MOLECULAR ALTERATIONS LESIONAL TAC SHOW A PREFERENCE IN METABOLIC-RELATED ALTERATIONS. 2020 2 3666 25 INFECTION, STEM CELLS AND CANCER SIGNALS. THE ASSOCIATION OF CANCER WITH PRECEDING PARASITIC INFECTIONS HAS BEEN OBSERVED FOR OVER 200 YEARS. SOME SUCH CANCERS ARISE FROM INFECTION OF TISSUE STEM CELLS BY VIRUSES WITH INSERTION OF VIRAL ONCOGENES INTO THE HOST DNA (MOUSE POLYOMA VIRUS, MOUSE MAMMARY TUMOR VIRUS). IN OTHER CASES THE VIRUS DOES NOT INSERT ITS DNA INTO THE HOST CELLS, BUT RATHER COMMANDEERS THE METABOLISM OF THE INFECTED CELLS, SO THAT THE CELLS CONTINUE TO PROLIFERATE AND DO NOT DIFFERENTIATE (HUMAN PAPILLOMA VIRUS AND CERVICAL CANCER). CYTOPLASMIC EPSTEIN BARR VIRUS INFECTION IS ASSOCIATED WITH A SPECIFIC GENE TRANSLOCATION (IG/C-MYC) THAT ACTIVATES PROLIFERATION OF AFFECTED CELLS (BURKITT LYMPHOMA). IN CHRONIC OSTEOMYELITIS AN INFLAMMATORY REACTION TO THE INFECTION APPEARS TO ACT THROUGH PRODUCTION OF INFLAMMATORY CYTOKINES AND OXYGEN RADICAL FORMATION TO INDUCE EPITHELIAL CANCERS. INFECTION WITH HELICOBACTER PYLORI LEADS TO EPIGENETIC CHANGES IN METHYLATION AND INFECTION BY A PARASITE. CLONORCHIS SINENSIS ALSO ACTS AS A PROMOTER OF CANCER OF THE BILE DUCTS OF THE LIVER (CHOLANIOCARCINOMA). THE COMMON THREAD AMONG THESE DIVERSE PATHWAYS IS THAT THE INFECTIONS ACT TO ALTER TISSUE STEM CELL SIGNALING WITH CONTINUED PROLIFERATION OF TUMOR TRANSIT AMPLIFYING CELLS. 2011 3 4605 30 NEGATIVE REGULATORS OF TGF-BETA1 SIGNALING IN RENAL FIBROSIS; PATHOLOGICAL MECHANISMS AND NOVEL THERAPEUTIC OPPORTUNITIES. ELEVATED EXPRESSION OF THE MULTIFUNCTIONAL CYTOKINE TRANSFORMING GROWTH FACTOR BETA1 (TGF-BETA1) IS CAUSATIVELY LINKED TO KIDNEY FIBROSIS PROGRESSION INITIATED BY DIABETIC, HYPERTENSIVE, OBSTRUCTIVE, ISCHEMIC AND TOXIN-INDUCED INJURY. THERAPEUTICALLY RELEVANT APPROACHES TO DIRECTLY TARGET THE TGF-BETA1 PATHWAY (E.G., NEUTRALIZING ANTIBODIES AGAINST TGF-BETA1), HOWEVER, REMAIN ELUSIVE IN HUMANS. TGF-BETA1 SIGNALING IS SUBJECTED TO EXTENSIVE NEGATIVE CONTROL AT THE LEVEL OF TGF-BETA1 RECEPTOR, SMAD2/3 ACTIVATION, COMPLEX ASSEMBLY AND PROMOTER ENGAGEMENT DUE TO ITS CRITICAL ROLE IN TISSUE HOMEOSTASIS AND NUMEROUS PATHOLOGIES. PROGRESSIVE KIDNEY INJURY IS ACCOMPANIED BY THE DEREGULATION (LOSS OR GAIN OF EXPRESSION) OF SEVERAL NEGATIVE REGULATORS OF THE TGF-BETA1 SIGNALING CASCADE BY MECHANISMS INVOLVING PROTEIN AND MRNA STABILITY OR EPIGENETIC SILENCING, FURTHER AMPLIFYING TGF-BETA1/SMAD3 SIGNALING AND FIBROSIS. EXPRESSION OF BONE MORPHOGENETIC PROTEINS 6 AND 7 (BMP6/7), SMAD7, SLOAN-KETTERING INSTITUTE PROTO-ONCOGENE (SKI) AND SKI-RELATED NOVEL GENE (SNON), PHOSPHATE TENSIN HOMOLOG ON CHROMOSOME 10 (PTEN), PROTEIN PHOSPHATASE MAGNESIUM/MANGANESE DEPENDENT 1A (PPM1A) AND KLOTHO ARE DRAMATICALLY DECREASED IN VARIOUS NEPHROPATHIES IN ANIMALS AND HUMANS ALBEIT WITH DIFFERENT KINETICS WHILE THE EXPRESSION OF SMURF1/2 E3 LIGASES ARE INCREASED. SUCH DEREGULATIONS FREQUENTLY INITIATE MALADAPTIVE RENAL REPAIR INCLUDING RENAL EPITHELIAL CELL DEDIFFERENTIATION AND GROWTH ARREST, FIBROTIC FACTOR (CONNECTIVE TISSUE GROWTH FACTOR (CTGF/CCN2), PLASMINOGEN ACTIVATOR INHIBITOR TYPE-1 (PAI-1), TGF-BETA1) SYNTHESIS/SECRETION, FIBROPROLIFERATIVE RESPONSES AND INFLAMMATION. THIS REVIEW ADDRESSES HOW LOSS OF THESE NEGATIVE REGULATORS OF TGF-BETA1 PATHWAY EXACERBATES RENAL LESION FORMATION AND DISCUSSES THE THERAPEUTIC VALUE IN RESTORING THE EXPRESSION OF THESE MOLECULES IN AMELIORATING FIBROSIS, THUS, PRESENTING NOVEL APPROACHES TO SUPPRESS TGF-BETA1 HYPERACTIVATION DURING CHRONIC KIDNEY DISEASE (CKD) PROGRESSION. 2021 4 2894 28 GASTRIC CANCER AS A STEM-CELL DISEASE: DATA AND HYPOTHESES. THE MAIN FUNCTION OF GASTRIC STEM CELLS IS TO MAINTAIN THE INTEGRITY OF THE GASTROINTESTINAL EPITHELIUM AND REPLENISH ALL THE MATURE CELL LINEAGES. IN ORDER TO ACCOMPLISH THIS, GASTRIC STEM CELLS PROLIFERATE AND SELF-RENEW, GIVING RISE TO TRANSIENT AMPLIFYING CELLS WHICH REPLACE THE CONSTANTLY RENEWING EPITHELIUM, ESPECIALLY AFTER INJURY INDUCED BY LONG-TERM INFLAMMATION. GASTRIC CANCER (GC) REMAINS THE FOURTH MOST COMMON CANCER AND THE SECOND LEADING CAUSE OF DEATH FOR CANCER IN THE WORLD. THE MOST ACCEPTED MODEL OF GASTRIC CARCINOGENESIS PROVIDES A MULTIFACTORIAL AND MULTISTEP PATHOGENESIS, INVOLVING A NUMBER OF INITIATORS AND OTHER CONTINUATOR AGENTS. HELICOBACTER PYLORI INFECTION IS RECOGNIZED AS A NECESSARY BUT INSUFFICIENT CAUSE OF GC. RECENT ADVANCES IN GASTRIC STEM CELL BIOLOGY POINT OUT TO TWO HYPOTHESES. IN THE FIRST, IT IS POSTULATED THAT RESIDENT STEM CELLS MAY, IN A CHRONICALLY INFLAMED ENVIRONMENT, AS IN THE CASE OF HELICOBACTER PYLORI-INDUCED GASTRITIS, ACCUMULATE OVER TIME A SERIES OF GENETIC AND EPIGENETIC CHANGES THAT LEAD TO THE EMERGENCE OF GC STEM CELLS. ALTERNATIVELY, THE SETTING OF CHRONIC INFLAMMATORY STRESS MAY LEAD TO LOSS OF THE INDIGENOUS GASTRIC STEM CELLS FROM THEIR NICHES, FOLLOWED BY RECRUITMENT AND ENGRAFTMENT OF BONE MARROW DERIVED STEM CELLS (BMDCS) INTO THE GASTRIC EPITHELIUM. IN THE MOUSE MODEL, INCREASING EVIDENCE SUPPORTS THE HYPOTHESIS THAT BMDCS ARE IMPORTANT CELLULAR SOURCE OF HELICOBACTER-INDUCED GC. THIS REVIEW HIGHLIGHTS DATA AND HYPOTHESES ABOUT GC AS A MODEL OF STEM-CELL DISEASE. 2014 5 2308 22 EPIGENETIC REGULATION OF CHEMOKINE (CC-MOTIF) LIGAND 2 IN INFLAMMATORY DISEASES. APPROPRIATE RESPONSES TO INFLAMMATION ARE CONDUCIVE TO PATHOGEN ELIMINATION AND TISSUE REPAIR, WHILE UNCONTROLLED INFLAMMATORY REACTIONS ARE LIKELY TO RESULT IN THE DAMAGE OF TISSUES. CHEMOKINE (CC-MOTIF) LIGAND 2 (CCL2) IS THE MAIN CHEMOKINE AND ACTIVATOR OF MONOCYTES, MACROPHAGES, AND NEUTROPHILS. CCL2 PLAYED A KEY ROLE IN AMPLIFYING AND ACCELERATING THE INFLAMMATORY CASCADE AND IS CLOSELY RELATED TO CHRONIC NON-CONTROLLABLE INFLAMMATION (CIRRHOSIS, NEUROPATHIC PAIN, INSULIN RESISTANCE, ATHEROSCLEROSIS, DEFORMING ARTHRITIS, ISCHEMIC INJURY, CANCER, ETC.). THE CRUCIAL REGULATORY ROLES OF CCL2 MAY PROVIDE POTENTIAL TARGETS FOR THE TREATMENT OF INFLAMMATORY DISEASES. THEREFORE, WE PRESENTED A REVIEW OF THE REGULATORY MECHANISMS OF CCL2. GENE EXPRESSION IS LARGELY AFFECTED BY THE STATE OF CHROMATIN. DIFFERENT EPIGENETIC MODIFICATIONS, INCLUDING DNA METHYLATION, POST-TRANSLATIONAL MODIFICATION OF HISTONES, HISTONE VARIANTS, ATP-DEPENDENT CHROMATIN REMODELLING, AND NON-CODING RNA, COULD AFFECT THE 'OPEN' OR 'CLOSED' STATE OF DNA, AND THEN SIGNIFICANTLY AFFECT THE EXPRESSION OF TARGET GENES. SINCE MOST EPIGENETIC MODIFICATIONS ARE PROVEN TO BE REVERSIBLE, TARGETING THE EPIGENETIC MECHANISMS OF CCL2 IS EXPECTED TO BE A PROMISING THERAPEUTIC STRATEGY FOR INFLAMMATORY DISEASES. THIS REVIEW FOCUSES ON THE EPIGENETIC REGULATION OF CCL2 IN INFLAMMATORY DISEASES. 2023 6 3226 26 HELICOBACTER PYLORI INFECTION, ONCOGENIC PATHWAYS AND EPIGENETIC MECHANISMS IN GASTRIC CARCINOGENESIS. CHRONIC COLONIZATION OF THE HUMAN STOMACH BY HELICOBACTER PYLORI, A GRAM-NEGATIVE BACTERIUM, IS THE MAJOR CAUSE OF CHRONIC GASTRITIS, PEPTIC ULCERS AND GASTRIC CANCER. RECENT PROGRESS HAS ELUCIDATED IMPORTANT BACTERIAL AND HOST FACTORS THAT ARE RESPONSIBLE FOR H. PYLORI-INDUCED GASTRIC INFLAMMATION AND GASTRIC MALIGNANCY. H. PYLORI CYTOTOXIN-ASSOCIATED ANTIGEN A IS THE MAJOR ONCOGENIC FACTOR INJECTED INTO HOST CELLS FROM BACTERIA AND IT DISRUPTS EPITHELIAL CELL FUNCTIONS. TOGETHER WITH H. PYLORI CAG PATHOGENICITY ISLAND, IT CAUSES GENERAL INFLAMMATORY STRESS WITHIN GASTRIC MUCOSA AND ACTIVATES MULTIPLE ONCOGENIC PATHWAYS IN EPITHELIAL CELLS. A GROWING LIST OF THESE PATHWAYS INCLUDES NF-KAPPAB, ACTIVATOR PROTEIN-1, PI3K, SIGNAL TRANSDUCERS AND ACTIVATORS OF TRANSCRIPTION 3, WNT/BETA-CATENIN AND CYCLOOXYGENASE 2. H. PYLORI INDUCES EPIGENETIC ALTERATIONS, SUCH AS DNA METHYLATION AND HISTONE MODIFICATION, WHICH PLAY CRITICAL ROLES IN ONCOGENIC TRANSFORMATION. IN ADDITION, INVESTIGATIONS INTO GASTRIC STEM CELL OR PROGENITOR CELL BIOLOGY HAVE SHED LIGHT ON THE MECHANISMS THROUGH WHICH GASTRIC CANCER MAY ORIGINATE. CONTINUED INVESTIGATION IN THESE AREAS WILL YIELD NOVEL INSIGHTS AND HELP TO ELUCIDATE THE MECHANISMS OF BACTERIA-INDUCED CARCINOGENESIS. 2010 7 1606 22 DNA METHYLATION, BACTERIA AND AIRWAY INFLAMMATION: LATEST INSIGHTS. PURPOSE OF REVIEW: DNA METHYLATION IS AN EPIGENETIC MECHANISM THAT HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC INFLAMMATORY DISEASES BY REGULATING DIFFERENTIATION, PROLIFERATION, APOPTOSIS, AND ACTIVATION OF IMMUNE CELLS. CHANGES IN THE METHYLATION STATUS OF RELEVANT GENES HAVE BEEN LINKED TO THE ORIGIN, PERPETUATION, AND SEVERITY OF AIRWAY DISEASES. THE DNA METHYLATION PROFILE CAN BE ALSO MODIFIED BY THE ACTION OF VIRAL AND BACTERIAL COLONIZATION. BACTERIA AND SPECIALLY STAPHYLOCOCCUS AUREUS TOXINS ARE RECOGNIZED INFLAMMATORY AMPLIFYING FACTORS IN BOTH LOWER AND UPPER AIRWAY CHRONIC DISEASES. THIS REVIEW SUMMARIZES THE EXISTENT KNOWLEDGE ABOUT THE ROLE OF DNA METHYLATION CHANGES IN CHRONIC AIRWAY DISEASES AND THE CONTRIBUTION OF BACTERIAL INFECTION ON THIS EVENT. RECENT FINDINGS: IT HAS BEEN DEMONSTRATED THAT CHANGES IN DNA METHYLATION, EITHER INTRINSIC OR INDUCED BY ALLERGEN OR INFECTION, MAY BE LINKED TO THE PATHOGENESIS OF ASTHMA AND ALLERGY. THESE CHANGES IN METHYLATION MAY SUPPRESS THE PRODUCTION OF ANTI-INFLAMMATORY MEDIATORS AND INCREASE THE SURVIVAL AND ACTIVATION OF PRO-INFLAMMATORY CELLS, AS WELL AS MODIFY THE IMMUNE RESPONSE IN RESPONSE TO BACTERIAL INFECTION, INCREASING THEIR SURVIVAL AND PATHOGENICITY WITHIN THE INFECTED ORGANISM. SUMMARY: UNDERSTANDING THE INTRINSIC EPIGENETIC MECHANISMS, AS WELL AS THE EFFECT OF ENVIRONMENT -FOR EXAMPLE, BACTERIAL INFECTION IN THE PATHOGENESIS OF AIRWAYS DISEASES - WILL GREATLY IMPROVE THE MANAGEMENT AND THE DIAGNOSIS OF THESE DISEASES. 2015 8 6273 24 THE ORIGINS OF GASTRIC CANCER FROM GASTRIC STEM CELLS: LESSONS FROM MOUSE MODELS. THE CELLULAR ORIGIN OF DIGESTIVE CANCERS HAS BEEN A LONG-STANDING QUESTION IN THE CANCER FIELD. MOUSE MODELS HAVE IDENTIFIED LONG-LIVED STEM CELLS IN MOST ORGAN SYSTEMS, INCLUDING THE LUMINAL GASTROINTESTINAL TRACT, AND NUMEROUS STUDIES HAVE POINTED TO TISSUE RESIDENT STEM CELLS AS THE MAIN CELLULAR ORIGIN OF CANCER. DURING GASTRIC CARCINOGENESIS, CHRONIC INFLAMMATION INDUCES GENETIC AND EPIGENETIC ALTERATIONS IN LONG-LIVED STEM CELLS, ALONG WITH EXPANSION OF STEM CELL NICHES, EVENTUALLY LEADING TO INVASIVE CANCER. THE GASTRIC CORPUS AND ANTRUM HAVE DISTINCT STEM CELLS AND STEM CELL NICHES, SUGGESTING DIFFERENTIAL REGULATION OF CANCER INITIATION AT THE 2 SITES. IN THIS SHORT REVIEW, WE DISCUSS RECENT EXPERIMENTAL MODELS AND HUMAN STUDIES, WHICH PROVIDE IMPORTANT INSIGHTS INTO THE PATHOGENESIS OF GASTRIC CANCER. 2017 9 2853 18 FROM HELICOBACTER PYLORI INFECTION TO GASTRIC CANCER: CURRENT EVIDENCE ON THE IMMUNE RESPONSE. GASTRIC CANCER (GC) IS THE RESULT OF A MULTIFACTORIAL PROCESS WHOSE MAIN COMPONENTS ARE INFECTION BY HELICOBACTER PYLORI (H. PYLORI), BACTERIAL VIRULENCE FACTORS, HOST IMMUNE RESPONSE AND ENVIRONMENTAL FACTORS. THE DEVELOPMENT OF THE NEOPLASTIC MICROENVIRONMENT ALSO DEPENDS ON GENETIC AND EPIGENETIC CHANGES IN ONCOGENES AND TUMOR SUPPRESSOR GENES, WHICH RESULTS IN DEREGULATION OF CELL SIGNALING PATHWAYS AND APOPTOSIS PROCESS. THIS REVIEW SUMMARIZES THE MAIN ASPECTS OF THE PATHOGENESIS OF GC AND THE IMMUNE RESPONSE INVOLVED IN CHRONIC INFLAMMATION GENERATED BY H. PYLORI. 2022 10 3224 26 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 11 4116 27 MECHANISMS OF AIRWAY EPITHELIAL INJURY AND ABNORMAL REPAIR IN ASTHMA AND COPD. THE AIRWAY EPITHELIUM COMPRISES OF DIFFERENT CELL TYPES AND ACTS AS A PHYSICAL BARRIER PREVENTING PATHOGENS, INCLUDING INHALED PARTICLES AND MICROBES, FROM ENTERING THE LUNGS. GOBLET CELLS AND SUBMUCOSAL GLANDS PRODUCE MUCUS THAT TRAPS PATHOGENS, WHICH ARE EXPELLED FROM THE RESPIRATORY TRACT BY CILIATED CELLS. BASAL CELLS ACT AS PROGENITOR CELLS, DIFFERENTIATING INTO DIFFERENT EPITHELIAL CELL TYPES, TO MAINTAIN HOMEOSTASIS FOLLOWING INJURY. ADHERENS AND TIGHT JUNCTIONS BETWEEN CELLS MAINTAIN THE EPITHELIAL BARRIER FUNCTION AND REGULATE THE MOVEMENT OF MOLECULES ACROSS IT. IN THIS REVIEW WE DISCUSS HOW ABNORMAL EPITHELIAL STRUCTURE AND FUNCTION, CAUSED BY CHRONIC INJURY AND ABNORMAL REPAIR, DRIVES AIRWAY DISEASE AND SPECIFICALLY ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). IN BOTH DISEASES, INHALED ALLERGENS, POLLUTANTS AND MICROBES DISRUPT JUNCTIONAL COMPLEXES AND PROMOTE CELL DEATH, IMPAIRING THE BARRIER FUNCTION AND LEADING TO INCREASED PENETRATION OF PATHOGENS AND A CONSTANT AIRWAY IMMUNE RESPONSE. IN ASTHMA, THE INFLAMMATORY RESPONSE PRECIPITATES THE EPITHELIAL INJURY AND DRIVES ABNORMAL BASAL CELL DIFFERENTIATION. THIS LEADS TO REDUCED CILIATED CELLS, GOBLET CELL HYPERPLASIA AND INCREASED EPITHELIAL MESENCHYMAL TRANSITION, WHICH CONTRIBUTE TO IMPAIRED MUCOCILIARY CLEARANCE AND AIRWAY REMODELLING. IN COPD, CHRONIC OXIDATIVE STRESS AND INFLAMMATION TRIGGER PREMATURE EPITHELIAL CELL SENESCENCE, WHICH CONTRIBUTES TO LOSS OF EPITHELIAL INTEGRITY AND AIRWAY INFLAMMATION AND REMODELLING. INCREASED NUMBERS OF BASAL CELLS SHOWING DEREGULATED DIFFERENTIATION, CONTRIBUTES TO CILIARY DYSFUNCTION AND MUCOUS HYPERPRODUCTION IN COPD AIRWAYS. DEFECTIVE ANTIOXIDANT, ANTIVIRAL AND DAMAGE REPAIR MECHANISMS, POSSIBLY DUE TO GENETIC OR EPIGENETIC FACTORS, MAY CONFER SUSCEPTIBILITY TO AIRWAY EPITHELIAL DYSFUNCTION IN THESE DISEASES. THE CURRENT EVIDENCE SUGGESTS THAT A CONSTANT CYCLE OF INJURY AND ABNORMAL REPAIR OF THE EPITHELIUM DRIVES CHRONIC AIRWAY INFLAMMATION AND REMODELLING IN ASTHMA AND COPD. MECHANISTIC UNDERSTANDING OF INJURY SUSCEPTIBILITY AND DAMAGE RESPONSE MAY LEAD TO IMPROVED THERAPIES FOR THESE DISEASES. 2023 12 6210 23 THE INTERPLAY BETWEEN KERATINOCYTES AND IMMUNE CELLS IN THE PATHOGENESIS OF PSORIASIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE RESULTING FROM GENETIC, EPIGENETIC, ENVIRONMENTAL, AND LIFESTYLE FACTORS. TO DATE, SEVERAL IMMUNOPATHOGENIC MECHANISMS OF PSORIASIS HAVE BEEN ELUCIDATED, AND, IN THE CURRENT MODEL, THE CROSS TALK BETWEEN AUTOREACTIVE T CELLS AND RESIDENT KERATINOCYTES GENERATES INFLAMMATORY AND IMMUNE CIRCUITS RESPONSIBLE FOR THE INITIATION, PROGRESSION, AND PERSISTENCE OF THE DISEASE. SEVERAL AUTOANTIGENS DERIVED FROM KERATINOCYTES (I.E., LL37 CATHELECIDIN/NUCLEIC ACID COMPLEXES, NEWLY GENERATED LIPID ANTIGENS) HAVE BEEN IDENTIFIED, WHICH MAY TRIGGER INITIAL ACTIVATION OF T CELLS, PARTICULARLY IL-17-PRODUCING T CELLS, T HELPER (TH)1 AND TH22 CELLS. HENCE, LYMPHOKINES RELEASED IN SKIN LESIONS ARE PIVOTAL FOR KERATINOCYTE ACTIVATION AND PRODUCTION OF INFLAMMATORY MOLECULES, WHICH IN TURN LEAD TO AMPLIFICATION OF THE LOCAL IMMUNE RESPONSES. INTRINSIC GENETIC ALTERATIONS OF KERATINOCYTES IN THE ACTIVATION OF SIGNAL TRANSDUCTION PATHWAYS DEPENDENT ON T-CELL-DERIVED CYTOKINES ARE ALSO FUNDAMENTAL. THE CURRENT REVIEW EMPHASIZES THE ABERRANT INTERPLAY OF IMMUNE CELLS AND SKIN-RESIDENT KERATINOCYTES IN ESTABLISHING AND SUSTAINING INFLAMMATORY AND IMMUNE RESPONSES IN PSORIASIS. 2018 13 1300 18 DEDIFFERENTIATION AND IN VIVO REPROGRAMMING OF COMMITTED CELLS IN WOUND REPAIR (REVIEW). ACCUMULATING EVIDENCE HAS SHOWN THAT CELL DEDIFFERENTIATION OR REPROGRAMMING IS A PIVOTAL PROCEDURE FOR ANIMALS TO DEAL WITH INJURY AND PROMOTE ENDOGENOUS TISSUE REPAIR. TISSUE DAMAGE IS A CRITICAL FACTOR THAT TRIGGERS CELL DEDIFFERENTIATION OR REPROGRAMMING IN VIVO. BY CONTRAST, MICROENVIRONMENTAL CHANGES, INCLUDING THE LOSS OF STEM CELLS, HYPOXIA, CELL SENESCENCE, INFLAMMATION AND IMMUNITY, CAUSED BY TISSUE DAMAGE CAN RETURN CELLS TO AN UNSTABLE STATE. IF THE WOUND PERSISTS IN THE LONG?TERM DUE TO CHRONIC DAMAGE, THEN DEDIFFERENTIATION OR REPROGRAMMING OF THE SURROUNDING CELLS MAY LEAD TO CARCINOGENESIS. IN RECENT YEARS, EXTENSIVE RESEARCH HAS BEEN PERFORMED INVESTIGATING CELL DEDIFFERENTIATION OR REPROGRAMMING IN VIVO, WHICH CAN HAVE SIGNIFICANT IMPLICATIONS FOR WOUND REPAIR, TREATMENT AND PREVENTION OF CANCER IN THE FUTURE. THE CURRENT REVIEW SUMMARIZES THE MOLECULAR EVENTS THAT ARE KNOWN TO DRIVE CELL DEDIFFERENTIATION DIRECTLY FOLLOWING TISSUE INJURY AND THE EFFECTS OF EPIGENETIC MODIFICATION ON DEDIFFERENTIATION OR REPROGRAMMING IN VIVO. IN ADDITION, THE PRESENT REVIEW EXPLORES THE INTRACELLULAR MECHANISM OF ENDOGENOUS TISSUE REPAIR AND ITS RELATIONSHIP WITH CANCER, WHICH IS ESSENTIAL FOR BALANCING THE RISK BETWEEN TISSUE REPAIR AND MALIGNANT TRANSFORMATION AFTER INJURY. 2022 14 3233 20 HELICOBACTER, INFLAMMATION, AND GASTRIC CANCER. HELICOBACTER PYLORI INFECTION LEADS TO LONG-LASTING CHRONIC INFLAMMATION AND REPRESENTS THE MOST COMMON RISK FACTOR UNDERLYING GASTRIC CANCER. RECENTLY, NEW INSIGHTS INTO THE MECHANISMS THROUGH WHICH H. PYLORI AND MUCOSAL INFLAMMATION LEAD TO CANCER DEVELOPMENT HAVE EMERGED. H. PYLORI VIRULENCE FACTORS, IN PARTICULAR SPECIFIC CAGA GENOTYPES, REPRESENT MAIN FACTORS IN GASTRIC CANCER, INDUCING ALTERED INTRACELLULAR SIGNALING IN EPITHELIAL CELLS. THE CHRONIC NATURE OF H. PYLORI INFECTION APPEARS TO RELATE TO THE VACA VIRULENCE FACTOR AND TH17/TREG MECHANISMS. A ROLE OF H. PYLORI INFECTION IN EPIGENETIC AND MICRORNA DEREGULATION HAS BEEN SHOWN. MUTATION OF THE EPITHELIAL CELL GENOME, A HALLMARK OF CANCER, WAS DEMONSTRATED TO ACCUMULATE IN H. PYLORI INFECTED STOMACH PARTLY DUE TO INADEQUATE DNA REPAIR. GASTRIC STEM CELLS WERE SHOWN TO BE TARGETS OF OXIDATIVE INJURY IN THE HELICOBACTER-INFLAMMATORY MILIEU. RECENT ADVANCES EMPHASIZING THE CONTRIBUTION OF BACTERIAL FACTORS, INFLAMMATORY MEDIATORS, AND THE HOST EPITHELIAL RESPONSE IN GASTRIC CARCINOGENESIS ARE REVIEWED. 2013 15 4430 29 MOLECULAR BIOLOGY OF ONCOGENIC INFLAMMATORY PROCESSES. I. NON-ONCOGENIC AND ONCOGENIC PATHOGENS, INTRINSIC INFLAMMATORY REACTIONS WITHOUT PATHOGENS, AND MICRORNA/DNA INTERACTIONS (REVIEW). IN SOME INFLAMMASOMES TUMOR CELLS ARE GENERATED. THE INTERNAL ENVIRONMENT OF THE INFLAMMASOME IS CONDUCIVE TO THE INDUCTION OF MALIGNANT TRANSFORMATION. EPIGENETIC CHANGES INITIATE THIS PROCESS. THE SUBVERTED STROMAL CONNECTIVE TISSUE CELLS ACT TO PROMOTE AND SUSTAIN THE PROCESS OF MALIGNANT TRANS-FORMATION. IN ITS EARLY STAGES, THE PREMALIGNANT CELLS DEPEND ON PARACRINE CIRCUITRIES FOR THE RECEPTION OF GROWTH FACTORS. THE LIGANDS ARE DERIVED FROM THE CONNECTIVE TISSUE, AND THE RECEPTORS ARE EXPRESSED ON THE RECIPIENT PREMALIGNANT CELLS. THE INITIAL EVENTS ARE NOT A DIRECT ATTACK ON THE PROTO-ONCOGENES, AND THUS IT MAY BE ENTIRELY REVERSIBLE. EPIGENETIC PROCESSES OF HYPERMETHYLATION OF THE GENES AT THE PROMOTERS OF TUMOR SUPPRESSOR GENES (TO SILENCE THEM), AND DEACETYLATION OF THE HISTONES AIMED AT THE PROMOTERS OF PROTO-ONCOGENES (TO ACTIVATE THEM) ARE ON-GOING. A LARGE NUMBER OF SHORT RNA SEQUENCES (INTERFERING, MICRO-, SHORT HAIRPIN, NON-CODING RNAS) SILENCE TUMOR SUPPRESSOR GENES, BY NEUTRALIZING THEIR MRNAS. IN A SERIAL SEQUENCE ONCOGENES UNDERGO AMPLIFICATIONS, POINT-MUTATIONS, TRANSLOCATIONS AND FUSIONS. IN ITS EARLIEST STAGE, THE PROCESS IS REVERSIBLE BY DEMETHYLATION OF THE SILENCED SUPPRESSOR GENE PROMOTERS (TO REACTIVATE THEM), OR RE-ACETYLATION OF THE HISTONES OF THE ONCOGENE PROMOTERS, THUS DE-ACTIVATING THEM. THE EXTERNAL ADMINISTRATION OF HISTONE DEACETYLASE INHIBITORS USUALLY LEADS TO THE RESTORATION OF HISTONE ACETYLATION. IN TIME, THE UNCORRECTED PROCESSES SOLIDIFY INTO CONSTITUTIVE AND IRREVERSIBLE GENE MUTATIONS. SOME OF THE PATHOGENS INDUCING INFLAMMATIONS WITH CONSQUENTIAL MALIGNANT TRANSFORMATION CONTAIN ONCOGENIC GENE SEQUENCES (PAPILLOMA VIRUSES, EPSTEIN-BARR VIRUS, KAPOSI'S SARCOMA-ASSOCIATED HERPESVIRUS, HEPATITIS B AND C VIRUSES, MERKEL CELL POLYOMA VIRUS, HELICOBACTER PYLORI, ENTEROTOXIGENIC BACTEROIDES FRAGILIS). THESE INDUCED MALIGNANCIES MAY BE MULTIFOCAL. OTHER PATHOGENS ARE DEVOID OF ANY KNOWN ONCOGENIC GENOMIC SEQUENCES (MYCOPLASMA VAV-CARCINOGENESIS, CHLAMYDIA MALT-LYMPHOMA GENESIS). IN THESE CASES THE HOST'S INFLAMMATORY REACTIONS INDUCE THE MALIGNANT TRANSFORMATION IN SERIAL SEQUENCES OF GENE ALTERATIONS INITIATED BY HYPOXIA AND REACTIVE OXYGEN AND NITROGEN SPECIES GENERATION. CARCINOGENIC INTRINSIC INFLAMMATORY PROCESSES ENDOGENOUSLY INITIATED WITHOUT A PATHOGEN ARE RECOGNIZED. CHRONIC INFLAMMATORY PROCESSES SIGNAL THE RNA/DNA COMPLEX. IN RESPONSE, THE DNA MAY REVERT INTO ITS ANCIENT PRIMORDIAL 'IMMORTAL' FORMAT, WHICH THE CLINICS RECOGNIZE AS 'ONCOGENESIS'. THE DNA REMAINS THE ULTIMATE MASTER OF BIOENGINEERING IN ORDER TO SUSTAIN LIFE. A DISCUSSION ON THE MOST VERSATILE AND RESISTANT PRIMORDIAL RNA/DNA COMPLEX AND THE PRE-, PROTO-, AND UNICELLULAR WORLD IN WHICH THEY CO-EXISTED IS INCLUDED. 2012 16 6202 35 THE INFLAMMATORY RESPONSE IN PSORIASIS: A COMPREHENSIVE REVIEW. PSORIASIS IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE CHARACTERIZED BY AN EXCESSIVELY ABERRANT HYPERPROLIFERATION OF KERATINOCYTES. THE PATHOGENESIS OF PSORIASIS IS COMPLEX AND THE EXACT MECHANISM REMAINS ELUSIVE. HOWEVER, PSORIASIS IS THOUGHT TO RESULT FROM A COMBINATION OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL INFLUENCES. RECENT STUDIES HAVE IDENTIFIED THAT EPIGENETIC FACTORS INCLUDING DYSREGULATED DNA METHYLATION LEVELS, ABNORMAL HISTONE MODIFICATION AND MICRORNAS EXPRESSIONS ARE INVOLVED IN THE DEVELOPMENT OF PSORIASIS. THE INTERPLAY OF IMMUNE CELLS AND CYTOKINES IS ANOTHER CRITICAL FACTOR IN THE PATHOGENESIS OF PSORIASIS. THESE FACTORS OR PATHWAYS INCLUDE TH1/TH2 HOMEOSTASIS, THE TH17/TREG BALANCE AND THE IL-23/TH17 AXIS. TH17 IS BELIEVED PARTICULARLY IMPORTANT IN PSORIASIS DUE TO ITS PRO-INFLAMMATORY EFFECTS AND ITS INVOLVEMENT IN AN INTEGRATED INFLAMMATORY LOOP WITH DENDRITIC CELLS AND KERATINOCYTES, CONTRIBUTING TO AN OVERPRODUCTION OF ANTIMICROBIAL PEPTIDES, INFLAMMATORY CYTOKINES, AND CHEMOKINES THAT LEADS TO AMPLIFICATION OF THE IMMUNE RESPONSE. IN ADDITION, OTHER PATHWAYS AND SIGNALING MOLECULES HAVE BEEN FOUND TO BE INVOLVED, INCLUDING TH9, TH22, REGULATORY T CELLS, GAMMADELTA T CELLS, CD8(+) T CELLS, AND THEIR RELATED CYTOKINES. UNDERSTANDING THE PATHOGENESIS OF PSORIASIS WILL ALLOW US TO DEVELOP INCREASINGLY EFFICIENT TARGETED TREATMENT BY BLOCKING RELEVANT INFLAMMATORY SIGNALING PATHWAYS AND MOLECULES. THERE IS NO CURE FOR PSORIASIS AT THE PRESENT TIME, AND MUCH OF THE TREATMENT INVOLVES MANAGING THE SYMPTOMS. THE BIOLOGICS, WHILE LACKING THE ADVERSE EFFECTS ASSOCIATED WITH SOME OF THE TRADITIONAL MEDICATIONS SUCH AS CORTICOSTEROIDS AND METHOTREXATE, HAVE THEIR OWN SET OF SIDE EFFECTS, WHICH MAY INCLUDE REACTIVATION OF LATENT INFECTIONS. SIGNIFICANT CHALLENGES REMAIN IN DEVELOPING SAFE AND EFFICACIOUS NOVEL TARGETED THERAPIES THAT DEPEND ON A BETTER UNDERSTANDING OF THE IMMUNOLOGICAL DYSFUNCTION IN PSORIASIS. 2016 17 2124 21 EPIGENETIC IMPLICATION OF GENE-ADJACENT RETROELEMENTS IN HELICOBACTER PYLORI-INFECTED ADULTS. A CHRONIC INFLAMMATORY CONDITION OF GASTRIC MUCOSA CAN FACILITATE THE INFLUX OF NEW STEM CELLS INTO THE STOMACH. EPIGENETIC CODES, SUCH AS DNA METHYLATION, MAY BE RESPONSIBLE FOR THE STABLE MAINTENANCE OF EPIGENETIC PHENOTYPES ESTABLISHED IN THE NEW STOMACH-ADAPTED STEM CELLS. A NUMBER OF HYPOTHESES HAVE BEEN MADE FOR THE ROLE OF CPG-ISLAND METHYLATION, WHICH IS COMMON IN THE HELICOBACTER PYLORI-INFECTED STOMACH. HOWEVER, THEY COULD NOT EXPLAIN THE PLAUSIBLE ROLE OF CPG-ISLAND METHYLATION IN THE RE-ESTABLISHMENT OF EPIGENETIC PHENOTYPES. THESE ISLANDS ARE HIGHLY REPETITIVE SEQUENCES DENSELY METHYLATED THROUGHOUT THE HUMAN GENOME, THE SO-CALLED PARASITIC RETROELEMENTS, WHICH EXPAND A NUMBER OF CDNA COPIES WITH REVERSE TRANSCRIPTASE. THE DENSELY METHYLATED RETROELEMENTS ADJACENT TO THE HOST GENES CAN FORM THE TRANSITIONAL-CPG SITES AROUND GENE-CONTROL REGIONS THAT ARE BARELY METHYLATED. THIS REVIEW FOCUSES ON THE PUTATIVE ROLE OF TRANSITIONAL CPG METHYLATION IN THE ADAPTIVE DIFFERENTIATION OF NEW STEM CELLS IN THE H. PYLORI-INFECTED STOMACH. 2012 18 6687 20 VALIDATION OF THE EPIGENETIC READER BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) AS A THERAPEUTIC TARGET FOR TREATMENT OF AIRWAY REMODELING. STRUCTURAL REMODELING IS CENTRAL TO THE INITIATION AND PROGRESSION OF MANY CHRONIC LUNG DISEASES, REPRESENTING AN IMPORTANT UNMET NEED. WE EXAMINE THE EVIDENCE SUPPORTING BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) AS A VALIDATED BIOLOGICAL TARGET FOR TREATMENT OF AIRWAY REMODELING. IN EPITHELIAL CELLS AND FIBROBLASTS, BRD4 SERVES AS A SCAFFOLD FOR CHROMATIN REMODELING COMPLEXES IN ACTIVE SUPER-ENHANCERS. IN RESPONSE TO INFLAMMATORY STIMULI, BRD4 IS REPOSITIONED TO INNATE AND MESENCHYMAL GENES ACTIVATING THEIR PRODUCTION. PROOF-OF-CONCEPT STUDIES SHOW PROMISING BENEFIT OF SELECTIVE BRD4 INHIBITORS IN DISRUPTING EPITHELIAL MESENCHYMAL TRANSITION AND MYOFIBROBLAST TRANSITION IN DIVERSE MODELS OF LUNG INJURY. RECENT IDENTIFICATION OF BIOMARKERS OF BRD4 PROVIDES A BASIS FOR FURTHER DRUG DEVELOPMENT FOR APPLICATION IN VIRAL-INDUCED AIRWAY INFLAMMATION, COPD AND INTERSTITIAL LUNG DISEASES. 2020 19 6841 24 [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 20 3221 15 HELICOBACTER PYLORI AND THE MOLECULAR PATHOGENESIS OF INTESTINAL-TYPE GASTRIC CARCINOMA. GASTRIC CARCINOMA IS AN INFLAMMATION-RELATED CANCER CAUSED BY LONG-TERM INFECTION WITH THE HUMAN BACTERIAL PATHOGEN, HELICOBACTER PYLORI. THE PATTERN OF ACUTE-ON-CHRONIC INFLAMMATION CAUSES PROGRESSIVE MUCOSAL DAMAGE WHICH MAY RESULT IN ATROPHY WITH METAPLASTIC EPITHELIA AND EVENTUALLY GASTRIC CANCER. RECENTLY, IT HAS BEEN RECOGNIZED THAT H. PYLORI CAN ALSO CAUSE GENETIC INSTABILITY SUCH AS DOUBLE-STRANDED DNA BREAKS AND CAN PRODUCE GENE ACTIVATION AND SILENCING VIA EPIGENETIC PATHWAYS. AS GENETIC INSTABILITY IS THE HALLMARK OF CANCER, WE HIGHLIGHT RECENT PROGRESS IN UNDERSTANDING THE GASTRIC CARCINOGENESIS IN RELATION TO H. PYLORI-RELATED INFLAMMATION, H. PYLORI-INDUCED DOUBLE-STRANDED DNA BREAKAGE AND ABERRANT GENE EXPRESSION AS WELL AS THE MECHANISMS AND ROLE OF H. PYLORI-ASSOCIATED EPIGENETIC CHANGE IN GENE EXPRESSION. 2014