1 5329 148 PURINERGIC SIGNALING IN THE LUMEN OF A NORMAL NEPHRON AND IN REMODELED PKD ENCAPSULATED CYSTS. THE NEPHRON IS THE FUNCTIONAL UNIT OF THE KIDNEY. BLOOD AND PLASMA ARE CONTINUALLY FILTERED WITHIN THE GLOMERULI THAT BEGIN EACH NEPHRON. ADENOSINE 5' TRIPHOSPHATE (ATP) AND ITS METABOLITES ARE FREELY FILTERED BY EACH GLOMERULUS AND ENTER THE LUMEN OF EACH NEPHRON BEGINNING AT THE PROXIMAL CONVOLUTED TUBULE (PCT). FLOW RATE, OSMOLALITY, AND OTHER MECHANICAL OR CHEMICAL STIMULI FOR ATP SECRETION ARE PRESENT IN EACH NEPHRON SEGMENT. THESE ATP-RELEASE STIMULI ARE ALSO DIFFERENT IN EACH NEPHRON SEGMENT DUE TO WATER OR SALT PERMEABILITY OR IMPERMEABILITY ALONG DIFFERENT LUMINAL MEMBRANES OF THE CELLS THAT LINE EACH NEPHRON SEGMENT. EACH OF THE ABOVE STIMULI CAN TRIGGER ADDITIONAL ATP RELEASE INTO THE LUMEN OF A NEPHRON SEGMENT. EACH NEPHRON-LINING EPITHELIAL CELL IS A POTENTIAL SOURCE OF SECRETED ATP. TOGETHER WITH FILTERED ATP AND ITS METABOLITES DERIVED FROM THE GLOMERULUS, SECRETED ATP AND ADENOSINE DERIVED FROM CELLS ALONG THE NEPHRON ARE LIKELY THE PRINCIPAL TWO OF SEVERAL NUCLEOTIDE AND NUCLEOSIDE CANDIDATES FOR RENAL AUTOCRINE AND PARACRINE LIGANDS WITHIN THE TUBULAR FLUID OF THE NEPHRON. THIS MINIREVIEW DISCUSSES THE FIRST PRINCIPLES OF PURINERGIC SIGNALING AS THEY RELATE TO THE NEPHRON AND THE URINARY BLADDER. THE REVIEW DISCUSSES HOW THE LUMEN OF A RENAL TUBULE PRESENTS AN IDEAL PURINERGIC SIGNALING MICROENVIRONMENT. THE REVIEW ALSO ILLUSTRATES HOW REMODELED AND ENCAPSULATED CYSTS IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE (ADPKD) AND REMODELED PSEUDOCYSTS IN AUTOSOMAL RECESSIVE PKD (ARPKD) OF THE RENAL COLLECTING DUCT LIKELY CREATE AN EVEN MORE IDEAL MICROENVIRONMENT FOR PURINERGIC SIGNALING. ONCE TRAPPED IN THESE CLOSED MICROENVIRONMENTS, PURINERGIC SIGNALING BECOMES CHRONIC AND LIKELY PLAYS A SIGNIFICANT EPIGENETIC AND DETRIMENTAL ROLE IN THE SECONDARY PROGRESSION OF PKD, ONCE THE REMODELING OF THE RENAL TISSUE HAS BEGUN. IN PKD CYSTIC MICROENVIRONMENTS, WE ARGUE THAT NORMAL PURINERGIC SIGNALING WITHIN THE LUMEN OF THE NEPHRON PROVIDES DETRIMENTAL ACCELERATION OF ADPKD ONCE REMODELING IS COMPLETE. 2008 2 5292 33 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 3 3847 24 IS CHRONIC LONG-TERM INHIBITION OF GASTRIC SECRETION REALLY DANGEROUS? POWERFUL GASTRIC SECRETION INHIBITORS PRODUCE CANCER IN THEIR TARGET ORGAN, THE STOMACH, IN EXPERIMENTAL ANIMALS. THE POSSIBLE MECHANISMS OF THE CARCINOGENIC EFFECT ARE DISCUSSED UNDER THE HEADINGS OF THE POTENTIAL NOXIOUS CHANGE IN THE GASTRIC LUMINAL CONTENTS, AS IS THE POSSIBILITY THAT THE DRUGS ACT AS EPIGENETIC OR GENOTOXIC CARCINOGENS. WHATEVER THE MECHANISMS OF THE DRUG-INDUCED CARCINOGENESIS, IT IS CLEAR THAT THERE IS A TOXICOLOGIC HAZARD, WHICH MUST BE ASSESSED RATIONALLY AND NOT BY MEANS OF SOPHISTRY. UNTIL THE DANGERS POSED BY POWERFUL GASTRIC SECRETORY INHIBITORS TO MAN HAVE BEEN BETTER EVALUATED, THESE DRUGS MUST NOT BE USED FOR TREATMENT OTHER THAN OF PATIENTS WITH GASTRINOMAS. 1988 4 3553 29 IMMUNOTOLERANCE OF DAIRY HEIFERS IN RESPONSE TO REPEATED EXPOSURE TO BACTERIAL LIPOPOLYSACCHARIDE ENDOTOXIN. DAIRY CATTLE FACE A VARIETY OF STRESSFUL EVENTS ON A DAILY BASIS. MORE SPECIFICALLY, CLIMATE CHANGE HAS RESULTED IN MORE FREQUENT HEAT STRESS EVENTS THAT INCREASE THE INCIDENCE OF CHRONIC BACTERIAL INFECTIONS BY INDUCING CONDITIONS LIKE LEAKY GUT SYNDROME, WHEREBY THE INTEGRITY OF THE INTESTINAL EPITHELIUM IS COMPROMISED ALLOWING FOR LUMINAL BACTERIAL LIPOPOLYSACCHARIDE (LPS) ENDOTOXIN TO INFILTRATE THE HOST'S BLOODSTREAM RESULTING IN ACUTE OR CHRONIC SYSTEMIC STIMULATION OF THE INNATE IMMUNE SYSTEM. REPEATED EXPOSURE TO LPS OVER A SHORT PERIOD OF TIME IS REPORTED TO INDUCE IMMUNOTOLERANCE WITHIN THE HOST. THIS LPS TOLERANCE IS AN ESSENTIAL IMMUNOHOMEOSTATIC RESPONSE THAT CAN PROTECT AGAINST OVER ACTIVATION OF THE INFLAMMATORY RESPONSE DURING SUBSEQUENT EXPOSURE TO LPS. IN THE PRESENT STUDY, HOLSTEIN CALVES (N = 20) WERE INITIALLY STRESS CHALLENGED WITH EITHER SALINE, OR 100, 200 OR 400 NG/KG OF LPS ADMINISTERED INTRAMUSCULAR, AND AGAIN RE-CHALLENGED WITH 200 NG/KG OF LPS 2-WEEKS LATER. SERUM WAS COLLECTED EVERY 2 HR FOR 6 HR TO PROFILE CHANGES IN CIRCULATORY STRESS BIOMARKERS AFTER THE REPEATED LPS EXPOSURES. HEIFERS THAT WERE INITIALLY CHALLENGED WITH 100, 200 AND 400 NG/KG OF LPS DEMONSTRATED SIGNIFICANTLY ATTENUATED CORTISOL RESPONSES IN THE SECOND CHALLENGE (P < 0.01, 0.01 AND 0.05, RESPECTIVELY), WHEREAS CONTROL ANIMALS WHO PREVIOUSLY RECEIVED SALINE DEMONSTRATED A STRONG CORTISOL RESPONSE AT 2 HR AFTER RECEIVING 200 NG/KG OF LPS (P < 0.05). THE CYTOKINE/CHEMOKINE (IL-6, CCL2, CCL3 AND CCL4) RESPONSES WERE ALSO ATTENUATED DURING THE LPS RECHALLENGE (P < 0.05). FINALLY, MICRORNA EXPRESSION PROFILES WERE DETERMINED TO ASSESS THE EPIGENETIC RESPONSE TO REPEATED LPS EXPOSURE. INTERESTINGLY, MIR-31 AND MIR-223 WERE DOWNREGULATED IN RESPONSE TO THE SECOND LPS CHALLENGE. THE PRESENT STUDY DEMONSTRATES THE DYNAMIC NATURE OF THE STRESS RESPONSE IN DAIRY CATTLE AS IT RELATES TO THE DEVELOPMENT OF LPS TOLERANCE. UNDERSTANDING THE ROLES OF VARIOUS STRESS BIOMARKERS IN THE CONTEXT OF INNATE IMMUNE CELL TOLERANCE IS ESSENTIAL FOR EVALUATING THEIR IMPACT ON IMMUNE SYSTEM HOMEOSTASIS. 2023 5 6273 23 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 6 3159 25 GLYPHOSATE PRIMES MAMMARY CELLS FOR TUMORIGENESIS BY REPROGRAMMING THE EPIGENOME IN A TET3-DEPENDENT MANNER. THE ACKNOWLEDGMENT THAT POLLUTANTS MIGHT INFLUENCE THE EPIGENOME RAISES SERIOUS CONCERNS REGARDING THEIR LONG-TERM IMPACT ON THE DEVELOPMENT OF CHRONIC DISEASES. THE HERBICIDE GLYPHOSATE HAS BEEN SCRUTINIZED FOR AN IMPACT ON CANCER INCIDENCE, BUT REPORTS DEMONSTRATE THE DIFFICULTY OF LINKING ESTIMATES OF EXPOSURE AND RESPONSE ANALYSIS. AN APPROACH TO BETTER APPREHEND A POTENTIAL RISK IMPACT FOR CANCER IS TO FOLLOW A SYNERGISTIC APPROACH, AS CANCER RARELY OCCURS IN RESPONSE TO ONE RISK FACTOR. THE KNOWN INFLUENCE OF GLYPHOSATE ON ESTROGEN-REGULATED PATHWAY MAKES IT A LOGICAL TARGET OF INVESTIGATION IN BREAST CANCER RESEARCH. WE HAVE USED NONNEOPLASTIC MCF10A CELLS IN A REPEATED GLYPHOSATE EXPOSURE PATTERN OVER 21 DAYS. GLYPHOSATE TRIGGERED A SIGNIFICANT REDUCTION IN DNA METHYLATION, AS SHOWN BY THE LEVEL OF 5-METHYLCYTOSINE DNA; HOWEVER, IN CONTRAST TO STRONG DEMETHYLATING AGENT AND CANCER PROMOTER UP PEPTIDE, GLYPHOSATE-TREATED CELLS DID NOT LEAD TO TUMOR DEVELOPMENT. WHEREAS UP ACTS THROUGH A DNMT1/PCNA/UHRF1 PATHWAY, GLYPHOSATE TRIGGERED INCREASED ACTIVITY OF TEN-ELEVEN TRANSLOCATION (TET)3. COMBINING GLYPHOSATE WITH ENHANCED EXPRESSION OF MICRORNA (MIR) 182-5P ASSOCIATED WITH BREAST CANCER INDUCED TUMOR DEVELOPMENT IN 50% OF MICE. CULTURE OF PRIMARY CELLS FROM RESECTED TUMORS REVEALED A LUMINAL B (ER+/PR-/HER2-) PHENOTYPE IN RESPONSE TO GLYPHOSATE-MIR182-5P EXPOSURE WITH SENSITIVITY TO TAMOXIFEN AND INVASIVE AND MIGRATORY POTENTIALS. TUMOR DEVELOPMENT COULD BE PREVENTED EITHER BY SPECIFICALLY INHIBITING MIR 182-5P OR BY TREATING GLYPHOSATE-MIR 182-5P-CELLS WITH DIMETHYLOXALLYL GLYCINE, AN INHIBITOR OF TET PATHWAY. LOOKING FOR POTENTIAL EPIGENETIC MARKS OF TET-MEDIATED GENE REGULATION UNDER GLYPHOSATE EXPOSURE, WE IDENTIFIED MTRNR2L2 AND DUX4 GENES, THE HYPOMETHYLATION OF WHICH WAS SUSTAINED EVEN AFTER STOPPING GLYPHOSATE EXPOSURE FOR 6 WEEKS. OUR FINDINGS REVEAL THAT LOW PRESSURE BUT SUSTAINED DNA HYPOMETHYLATION OCCURRING VIA THE TET PATHWAY PRIMES CELLS FOR ONCOGENIC RESPONSE IN THE PRESENCE OF ANOTHER POTENTIAL RISK FACTOR. THESE RESULTS WARRANT FURTHER INVESTIGATION OF GLYPHOSATE-MEDIATED BREAST CANCER RISK. 2019 7 6201 26 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 8 1395 33 DIET AND MICROBIOME IN THE BEGINNING OF THE SEQUENCE OF GUT INFLAMMATION. INFLAMMATORY BOWEL DISEASE (IBD) IS A CHRONIC INFLAMMATORY CONDITION OF THE GASTROINTESTINAL TRACT DUE, AT LEAST PARTIALLY, TO AN ABERRANT AND EXCESSIVE MUCOSAL IMMUNE RESPONSE TO GUT BACTERIA IN GENETICALLY-PREDISPOSED INDIVIDUALS UNDER CERTAIN ENVIRONMENTAL FACTORS. THE INCIDENCE OF IBD IS RISING IN WESTERN AND NEWLY INDUSTRIALIZED COUNTRIES, PARALLELING THE INCREASE OF WESTERNIZED DIETARY PATTERNS, THROUGH NEW ANTIGENS, EPITHELIAL FUNCTION AND PERMEABILITY, EPIGENETIC MECHANISMS (E.G., DNA METHYLATION), AND ALTERATION OF THE GUT MICROBIOME. ALTERATION IN THE COMPOSITION AND FUNCTIONALITY OF THE GUT MICROBIOME (INCLUDING BACTERIA, VIRUSES AND FUNGI) SEEMS TO BE A NUCLEAR PATHOGENIC FACTOR. THE MICROBIOME ITSELF IS DYNAMIC, AND THE CHANGES IN FOOD QUALITY, DIETARY HABITS, LIVING CONDITIONS AND HYGIENE OF THESE WESTERN SOCIETIES, COULD INTERACT IN A COMPLEX MANNER AS MODULATORS OF DYSBIOSIS, THEREBY INFLUENCING THE ACTIVATION OF IMMUNE CELLS' PROMOTING INFLAMMATION. THE MICROBIOME PRODUCES DIVERSE SMALL MOLECULES VIA SEVERAL METABOLIC WAYS, WITH THE FIBER-DERIVED SHORT-CHAIN FATTY ACIDS (I.E., BUTYRATE) AS MAIN ELEMENTS AND HAVING ANTI-INFLAMMATORY EFFECTS. THESE METABOLITES AND SOME MICRONUTRIENTS OF THE DIET (I.E., VITAMINS, FOLIC ACID, BETA CAROTENE AND TRACE ELEMENTS) ARE REGULATORS OF INNATE AND ADAPTIVE INTESTINAL IMMUNE HOMEOSTASIS. AN EXCESSIVE AND UNHEALTHY CONSUMPTION OF SUGAR, ANIMAL FAT AND A LOW-VEGETABLE AND -FIBER DIET ARE RISK FACTORS FOR IBD APPEARANCE. FURTHERMORE, METABOLISM OF NUTRIENTS IN INTESTINAL EPITHELIUM AND IN GUT MICROBIOTA IS ALTERED BY INFLAMMATION, CHANGING THE DEMAND FOR NUTRIENTS NEEDED FOR HOMEOSTASIS. THIS ROLE OF FOOD AND A REDUCED GUT MICROBIAL DIVERSITY IN CAUSING IBD MIGHT ALSO HAVE A PROPHYLACTIC OR THERAPEUTIC ROLE FOR IBD. THE RELATIONSHIP BETWEEN DIETARY INTAKE, SYMPTOMS, AND BOWEL INFLAMMATION COULD LEAD TO DIETARY AND LIFESTYLE RECOMMENDATIONS, INCLUDING DIETS WITH ABUNDANT FRUITS, VEGETABLES, OLIVE OIL AND OILY FISH, WHICH HAVE ANTI-INFLAMMATORY EFFECTS AND COULD PREVENT DYSBIOSIS AND IBD. DIETARY MODULATION AND APPROPRIATE EXCLUSION DIETS MIGHT BE A NEW COMPLEMENTARY MANAGEMENT FOR TREATMENT AT DISEASE FLARES AND IN REFRACTORY PATIENTS, EVEN REDUCING COMPLICATIONS, HOSPITALIZATIONS AND SURGERY, THROUGH MODIFYING THE LUMINAL INTESTINAL ENVIRONMENT. 2021 9 6671 26 UROPATHOGENIC ESCHERICHIA COLI INFECTION-INDUCED EPITHELIAL TRAINED IMMUNITY IMPACTS URINARY TRACT DISEASE OUTCOME. PREVIOUS URINARY TRACT INFECTIONS (UTIS) CAN PREDISPOSE ONE TO FUTURE INFECTIONS; HOWEVER, THE UNDERLYING MECHANISMS AFFECTING RECURRENCE ARE POORLY UNDERSTOOD. WE PREVIOUSLY FOUND THAT UTIS IN MICE CAUSE DIFFERENTIAL BLADDER EPITHELIAL (UROTHELIAL) REMODELLING, DEPENDING ON DISEASE OUTCOME, THAT IMPACTS SUSCEPTIBILITY TO RECURRENT UTI. HERE WE COMPARED UROTHELIAL STEM CELL (USC) LINES ISOLATED FROM MICE WITH A HISTORY OF EITHER RESOLVED OR CHRONIC UROPATHOGENIC ESCHERICHIA COLI (UPEC) INFECTION, ELUCIDATING EVIDENCE OF MOLECULAR IMPRINTING THAT INVOLVED EPIGENETIC CHANGES, INCLUDING DIFFERENCES IN CHROMATIN ACCESSIBILITY, DNA METHYLATION AND HISTONE MODIFICATION. EPIGENETIC MARKS IN USCS FROM CHRONICALLY INFECTED MICE ENHANCED CASPASE-1-MEDIATED CELL DEATH UPON UPEC INFECTION, PROMOTING BACTERIAL CLEARANCE. INCREASED PTGS2OS2 EXPRESSION ALSO OCCURRED, POTENTIALLY CONTRIBUTING TO SUSTAINED CYCLOOXYGENASE-2 EXPRESSION, BLADDER INFLAMMATION AND MUCOSAL WOUNDING-RESPONSES ASSOCIATED WITH SEVERE RECURRENT CYSTITIS. THUS, UPEC INFECTION ACTS AS AN EPI-MUTAGEN REPROGRAMMING THE UROTHELIAL EPIGENOME, LEADING TO UROTHELIAL-INTRINSIC REMODELLING AND TRAINING OF THE INNATE RESPONSE TO SUBSEQUENT INFECTION. 2023 10 3170 26 GUT INFLAMMATION AND TUMORIGENESIS: EVERY SITE HAS A DIFFERENT TALE TO TELL. GUT INFLAMMATION HAS BEEN CORRELATED WITH CANCEROGENESIS BY DISRUPTING GASTROINTESTINAL HOMEOSTASIS. NUMEROUS CHRONIC INFLAMMATORY DISORDERS OF THE TUBULAR GASTROINTESTINAL TRACT (E.G., GASTROESOPHAGEAL REFLUX DISEASE, HELICOBACTER PYLORI-INDUCED AND AUTOIMMUNE CHRONIC GASTRITIS, CELIAC DISEASE, AND INFLAMMATORY BOWEL DISEASES) HAVE BEEN VARIABLY ASSOCIATED WITH AN INCREASED NEOPLASTIC RISK. GASTROINTESTINAL INFLAMMATION-INDUCED NEOPLASMS INCLUDE EPITHELIAL TUMORS (ESOPHAGEAL SQUAMOUS CELL CARCINOMA AND ADENOCARCINOMA, GASTRIC ADENOCARCINOMA AND NEUROENDOCRINE TUMORS, SMALL BOWEL ADENOCARCINOMA AND NEUROENDOCRINE TUMORS, AND COLORECTAL CANCER) AND LYMPHOMAS (SUCH AS GASTRIC MARGINAL ZONE LYMPHOMAS AND ENTEROPATHY-ASSOCIATED T CELL LYMPHOMA). IN THE LAST DECADES, NUMEROUS STUDIES HAVE INVESTIGATED THE PATHOGENETIC MECHANISMS AND THE MICROENVIRONMENTAL/MICROBIOME CHANGES THAT TRIGGER GENETIC AND/OR EPIGENETIC ALTERATIONS EVENTUALLY LEADING TO TUMORIGENESIS, OFTEN THROUGH A HISTOLOGICALLY RECOGNIZABLE INFLAMMATION-DYSPLASIA-CARCINOMA CANCEROGENIC SEQUENCE. IN THE PRESENT REVIEW, AN OVERVIEW OF THE CURRENT KNOWLEDGE ON THE LINKS BETWEEN INFLAMMATORY DISEASES AND NEOPLASMS OF THE TUBULAR GI TRACT, APPLYING A SITE-BY-SITE APPROACH, IS PROVIDED. 2023 11 1863 29 EMERGENCE OF MUC1 IN MAMMALS FOR ADAPTATION OF BARRIER EPITHELIA. THE MUCIN 1 (MUC1) GENE WAS DISCOVERED BASED ON ITS OVEREXPRESSION IN HUMAN BREAST CANCERS. SUBSEQUENT WORK DEMONSTRATED THAT MUC1 IS ABERRANTLY EXPRESSED IN CANCERS ORIGINATING FROM OTHER DIVERSE ORGANS, INCLUDING SKIN AND IMMUNE CELLS. THESE FINDINGS SUPPORTED A ROLE FOR MUC1 IN THE ADAPTATION OF BARRIER TISSUES TO INFECTION AND ENVIRONMENTAL STRESS. OF FUNDAMENTAL IMPORTANCE FOR THIS EVOLUTIONARY ADAPTATION WAS INCLUSION OF A SEA DOMAIN, WHICH CATALYZES AUTOPROTEOLYSIS OF THE MUC1 PROTEIN AND FORMATION OF A NON-COVALENT HETERODIMERIC COMPLEX. THE RESULTING MUC1 HETERODIMER IS POISED AT THE APICAL CELL MEMBRANE TO RESPOND TO LOSS OF HOMEOSTASIS. DISRUPTION OF THE COMPLEX RELEASES THE MUC1 N-TERMINAL (MUC1-N) SUBUNIT INTO A PROTECTIVE MUCOUS GEL. CONVERSELY, THE TRANSMEMBRANE C-TERMINAL (MUC1-C) SUBUNIT ACTIVATES A PROGRAM OF LINEAGE PLASTICITY, EPIGENETIC REPROGRAMMING AND REPAIR. THIS MUC1-C-ACTIVATED PROGRAM APPARENTLY EVOLVED FOR BARRIER TISSUES TO MOUNT SELF-REGULATING PROLIFERATIVE, INFLAMMATORY AND REMODELING RESPONSES ASSOCIATED WITH WOUND HEALING. EMERGING EVIDENCE INDICATES THAT MUC1-C UNDERPINS INFLAMMATORY ADAPTATION OF TISSUE STEM CELLS AND IMMUNE CELLS IN THE BARRIER NICHE. THIS REVIEW FOCUSES ON HOW PROLONGED ACTIVATION OF MUC1-C BY CHRONIC INFLAMMATION IN THESE NICHES PROMOTES THE CANCER STEM CELL (CSC) STATE BY ESTABLISHING AUTO-INDUCTIVE NODES THAT DRIVE SELF-RENEWAL AND TUMORIGENICITY. 2022 12 3803 30 INTESTINAL METAPLASIA OF THE STOMACH. A STATUS REPORT. INTESTINAL METAPLASIA IN THE STOMACH INCREASES THE RISK OF GASTRIC CANCER, AND THE INCREASED RISK IS PROPORTIONAL TO THE EXTENT OF THE METAPLASIA. THIS RISK COULD BE GENERATED BY ONE OR MORE MECHANISMS: (1) THE METAPLASTIC TISSUE IS AN EARLY STEP IN A MULTISTEP INDUCTION PROCESS; (2) THE METAPLASTIC TISSUE IS AN EPIGENETIC CHANGE THAT RAISES THE PH OF GASTRIC JUICE BY REPLACING OXYNTIC MUCOSA, FAVORING THE GROWTH OF A BACTERIA CAPABLE OF GENERATING ENDOGENOUS MUTAGENS; AND/OR (3) THE METAPLASIA IS ONLY A MARKER FOR CHRONIC GASTRITIS DUE TO H. PYLORI INFECTION OR PERNICIOUS ANEMIA. WITH THE LAST MECHANISM, THE INFLAMMATORY RESPONSE FAVORS INTRAMURAL MUTAGENESIS THAT MIGHT RESULT IN METAPLASIA OR NEOPLASIA AS INDEPENDENT EVENTS. FINDING GENE REARRANGEMENTS COMMON TO BOTH METAPLASTIC AND NEOPLASTIC TISSUE MAY ESTABLISH A DIRECT LINK BETWEEN THEM, BUT TOO FEW HAVE BEEN IDENTIFIED TO ACCOUNT FOR THE LARGE NUMBER OF STOMACH CANCERS THAT DEVELOP IN HIGH RISK POPULATIONS. HISTOCHEMICAL AND IMMUNOCHEMICAL STAINS THAT IDENTIFY ENZYMES OR MUCOSUBSTANCES MAY SUGGEST THAT METAPLASTIC EPITHELIAL CELLS RESEMBLE SMALL OR LARGE INTESTINAL CELLS, BUT THEY ARE DISTINCTLY DIFFERENT FROM BOTH. MOREOVER, THESE STAINS DO NOT INDICATE WHETHER A GIVEN CYTOLOGIC CHANGE IS GENETIC OR EPIGENETIC; THEREFORE, THEY CANNOT BE USED TO DEFINE THE RELATIONSHIP BETWEEN METAPLASIA AND NEOPLASIA. IT IS UNNECESSARY FOR PRACTICING PHYSICIANS TO AWAIT RESOLUTION OF THIS QUESTION. IT CAN BE ASSUMED THAT ANY PERSON WITH EXTENSIVE METAPLASIA IS AT HIGH RISK FOR GASTRIC CANCER AND SHOULD BE SUBJECT TO PERIODIC SCREENING. THE EXTENT OF THE METAPLASTIC PROCESS IS PROBABLY MORE IMPORTANT THAN THE METAPLASTIC SUBTYPE. 1994 13 3804 22 INTESTINAL MICROBIOTA, CHRONIC INFLAMMATION, AND COLORECTAL CANCER. IN ADDITION TO GENETIC AND EPIGENETIC FACTORS, VARIOUS ENVIRONMENTAL FACTORS, INCLUDING DIET, PLAY IMPORTANT ROLES IN THE DEVELOPMENT OF COLORECTAL CANCER (CRC). RECENTLY, THERE IS INCREASING INTEREST IN THE INTESTINAL MICROBIOTA AS AN ENVIRONMENTAL RISK FACTOR FOR CRC, BECAUSE DIET ALSO INFLUENCES THE COMPOSITION OF THE INTESTINAL MICROBIOTA. THE HUMAN INTESTINAL MICROBIOTA COMPRISES ABOUT 100 TRILLION MICROBES. THIS MICROBIOME THRIVES ON UNDIGESTED DIETARY RESIDUES IN THE INTESTINAL LUMEN AND PRODUCES VARIOUS METABOLITES. IT IS WELL KNOWN THAT THE DIETARY RISK FACTORS FOR CRC ARE MEDIATED BY DYSBIOSIS OF THE INTESTINAL MICROBIOTA AND THEIR METABOLITES. IN THIS REVIEW, WE DESCRIBE THE BACTERIAL TAXA ASSOCIATED WITH CRC, INCLUDING FUSOBACTERIUM NUCLEATUM, ENTEROTOXIGENIC BACTEROIDES FRAGILIS, ESCHERICHIA COLI, AND BUTYRATE-PRODUCING BACTERIA. WE ALSO DISCUSS THE HOST-DIET INTERACTION IN COLORECTAL CARCINOGENESIS. 2018 14 6068 28 THE DIET AS A CAUSE OF HUMAN PROSTATE CANCER. ASYMPTOMATIC PROSTATE INFLAMMATION AND PROSTATE CANCER HAVE REACHED EPIDEMIC PROPORTIONS AMONG MEN IN THE DEVELOPED WORLD. ANIMAL MODEL STUDIES IMPLICATE DIETARY CARCINOGENS, SUCH AS THE HETEROCYCLIC AMINES FROM OVER-COOKED MEATS AND SEX STEROID HORMONES, PARTICULARLY ESTROGENS, AS CANDIDATE ETIOLOGIES FOR PROSTATE CANCER. EACH ACTS BY CAUSING EPITHELIAL CELL DAMAGE, TRIGGERING AN INFLAMMATORY RESPONSE THAT CAN EVOLVE INTO A CHRONIC OR RECURRENT CONDITION. THIS MILIEU APPEARS TO SPAWN PROLIFERATIVE INFLAMMATORY ATROPHY (PIA) LESIONS, A TYPE OF FOCAL ATROPHY THAT REPRESENTS THE EARLIEST OF PROSTATE CANCER PRECURSOR LESIONS. RARE PIA LESIONS CONTAIN CELLS WHICH EXHIBIT HIGH C-MYC EXPRESSION, SHORTENED TELOMERE SEGMENTS, AND EPIGENETIC SILENCING OF GENES SUCH AS GSTP1, ENCODING THE PI-CLASS GLUTATHIONE S-TRANSFERASE, ALL CHARACTERISTIC OF PROSTATIC INTRAEPITHELIAL NEOPLASIA (PIN) AND PROSTATE CANCER. SUBSEQUENT GENETIC CHANGES, SUCH AS THE GENE TRANSLOCATIONS/DELETIONS THAT GENERATE FUSION TRANSCRIPTS BETWEEN ANDROGEN-REGULATED GENES (SUCH AS TMPRSS2) AND GENES ENCODING ETS FAMILY TRANSCRIPTION FACTORS (SUCH AS ERG1), ARISE IN PIN LESIONS AND MAY PROMOTE INVASIVENESS CHARACTERISTIC OF PROSTATIC ADENOCARCINOMA CELLS. LETHAL PROSTATE CANCERS CONTAIN MARKEDLY CORRUPTED GENOMES AND EPIGENOMES. EPIGENETIC SILENCING, WHICH SEEMS TO ARISE IN RESPONSE TO THE INFLAMED MICROENVIRONMENT GENERATED BY DIETARY CARCINOGENS AND/OR ESTROGENS AS PART OF AN EPIGENETIC "CATASTROPHE" AFFECTING HUNDREDS OF GENES, PERSISTS TO DRIVE CLONAL EVOLUTION THROUGH METASTATIC DISSEMINATION. THE CAUSE OF THE INITIAL EPIGENETIC "CATASTROPHE" HAS NOT BEEN DETERMINED BUT LIKELY INVOLVES DEFECTIVE CHROMATIN STRUCTURE MAINTENANCE BY OVER-EXUBERANT DNA METHYLATION OR HISTONE MODIFICATION. WITH DIETARY CARCINOGENS AND ESTROGENS DRIVING PRO-CARCINOGENIC INFLAMMATION IN THE DEVELOPED WORLD, IT IS TEMPTING TO SPECULATE THAT DIETARY COMPONENTS ASSOCIATED WITH DECREASED PROSTATE CANCER RISK, SUCH AS INTAKE OF FRUITS AND VEGETABLES, ESPECIALLY TOMATOES AND CRUCIFERS, MIGHT ACT TO ATTENUATE THE RAVAGES OF THE CHRONIC OR RECURRENT INFLAMMATORY PROCESSES. SPECIFICALLY, NUTRITIONAL AGENTS MIGHT PREVENT PIA LESIONS OR REDUCE THE PROPENSITY OF PIA LESIONS TO SUFFER "CATASTROPHIC" EPIGENOME CORRUPTION. 2014 15 5181 18 PREMALIGNANT LESIONS IN GASTRIC CANCER. DESPITE A PLATEAU IN INCIDENCE, GASTRIC CANCER IS ONE OF THE MOST COMMON CANCERS WORLDWIDE AND CAUSES CONSIDERABLE MORBIDITY AND MORTALITY. PREMALIGNANT GASTRIC LESIONS ARE WELL KNOWN RISK FACTORS FOR THE DEVELOPMENT OF INTESTINAL-TYPE GASTRIC ADENOCARCINOMAS. IN THIS MULTISTEP MODEL OF GASTRIC CARCINOGENESIS, HELICOBACTER PYLORI CAUSES CHRONIC ACTIVE INFLAMMATION OF THE GASTRIC MUCOSA, WHICH SLOWLY PROGRESSES THROUGH THE PREMALIGNANT STAGES OF ATROPHIC GASTRITIS, INTESTINAL METAPLASIA, AND ADENOMA/DYSPLASIA TO GASTRIC CARCINOMA. THIS PROGRESSION IS PARALLELED BY A STEPWISE ACCUMULATION OF MULTIPLE GENETIC AND EPIGENETIC ABNORMALITIES. DETECTION, TREATMENT, AND MOLECULAR ANALYSES OF PREMALIGNANT LESIONS MAY THUS PROVIDE A BASIS FOR GASTRIC CANCER PREVENTION. THIS REVIEW DESCRIBES AN OVERVIEW OF CURRENT KNOWLEDGE ON PREMALIGNANT GASTRIC LESIONS. IT ALSO REVIEWS THE ISSUE OF SURVEILLANCE OF PATIENTS WITH PREMALIGNANT LESIONS IN ORDER TO IMPROVE THE SURVIVAL OF PATIENTS WITH GASTRIC CANCER. 2010 16 2894 30 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 17 5180 18 PREMALIGNANT CONDITIONS OF GASTRIC CANCER. PREMALIGNANT LESIONS OF GASTRIC CANCER ENCOMPASS A VARIETY OF CONDITIONS SUCH AS CHRONIC GASTRITIS, INTESTINAL METAPLASIA AND DYSPLASIA, IN WHICH ELEVATED RISK OF DEVELOPING GASTRIC CANCER HAVE BEEN DOCUMENTED. AMONG THEM, INTESTINAL METAPLASIA IS FREQUENTLY ENCOUNTERED IN OUR DAILY ENDOSCOPIC EXAMINATION, YET ITS CLINICAL SIGNIFICANCE IS OFTEN UNDERESTIMATED DESPITE OF A NUMBER OF REPORTS DEMONSTRATING GENETIC AND EPIGENETIC ALTERATIONS IN THE INTESTINAL METAPLASTIC MUCOSA. IN THIS REVIEW, I WILL DESCRIBE THE MOLECULAR MECHANISMS OF PHENOTYPIC CHANGES FROM GASTRIC MUCOSA TO INTESTINAL METAPLASIA BASED ON OUR ANALYSIS OF MOUSE MODEL OF INTESTINAL METAPLASIA GENERATED BY ECTOPIC EXPRESSION OF CDX2 IN CONJUNCTION WITH THE STUDIES WITH HUMAN INTESTINAL METAPLASIA. 2013 18 4512 21 MUC1-C IN CHRONIC INFLAMMATION AND CARCINOGENESIS; EMERGENCE AS A TARGET FOR CANCER TREATMENT. CHRONIC INFLAMMATION IS A HIGHLY PREVALENT CONSEQUENCE OF CHANGES IN ENVIRONMENTAL AND LIFESTYLE FACTORS THAT CONTRIBUTE TO THE DEVELOPMENT OF CANCER. THE BASIS FOR THIS CRITICAL ASSOCIATION HAS LARGELY REMAINED UNCLEAR. THE MUC1 GENE EVOLVED IN MAMMALS TO PROTECT EPITHELIA FROM THE EXTERNAL ENVIRONMENT. THE MUC1-C SUBUNIT PROMOTES RESPONSES FOUND IN WOUND HEALING AND CANCER. MUC1-C INDUCES EMT, EPIGENETIC REPROGRAMMING, DEDIFFERENTIATION AND PLURIPOTENCY FACTOR EXPRESSION, WHICH WHEN PROLONGED IN CHRONIC INFLAMMATION PROMOTE CANCER PROGRESSION. AS DISCUSSED IN THIS REVIEW, MUC1-C ALSO DRIVES DRUG RESISTANCE AND IMMUNE EVASION, AND IS AN IMPORTANT TARGET FOR CANCER THERAPEUTICS NOW UNDER DEVELOPMENT. 2020 19 196 23 ACID REFLUX AND OESOPHAGEAL CANCER. BARRETT'S METAPLASIA IS ONE OF THE COMMONEST PREMALIGNANT LESIONS IN THE WESTERN WORLD FOLLOWING COLORECTAL ADENOMAS. ONE IN 50 OF THE ADULT POPULATION DEVELOPS BARRETT'S AS A CONSEQUENCE OF CHRONIC GASTRO-OESOPHAGEAL REFLUX. THE MUCOSAL INFLAMMATION SEEN WITHIN PATIENTS WITH GASTRO-OESOPHAGEAL REFLUX SEEMS LIKELY TO DRIVE THE GROWTH OF THE METAPLASTIC MUCOSA AND ALSO HELP DIRECT FURTHER ONCOLOGICAL CHANGE, YET THE MOLECULAR EVENTS THAT CHARACTERIZE THE PATHWAY FROM INFLAMMATION TO METAPLASIA TO DYSPLASIA AND ADENOCARCINOMA ARE POORLY UNDERSTOOD. THERE IS HOPE THAT UNDERSTANDING THE ROLE OF OESOPHAGEAL INFLAMMATION WILL PROVIDE IMPORTANT INSIGHT INTO THE DEVELOPMENT OF BARRETT'S METAPLASIA AND OESOPHAGEAL CANCER. THIS CHAPTER WILL DISCUSS THE INFLAMMATION SEEN WITHIN CONTEXT OF BARRETT'S OESOPHAGUS AND ALSO CLINICAL TRIALS WHICH HOPE TO ADDRESS THIS COMMON PREMALIGNANT DISEASE. THERE ARE SEVERAL ONGOING CLINICAL TRIALS WHICH ARE AIMING TO PROVIDE DATA USING ANTI-INFLAMMATORY THERAPIES TO TACKLE THIS IMPORTANT PREMALIGNANT CONDITION. THERE IS NEW DATA PRESENTED WHICH SUGGESTS THAT DATA FROM THE ASPIRIN ESOMEPRAZOLE CHEMOPREVENTION TRIAL (ASPECT) MAY HOLD THE CLUE TO DISEASE TREATMENT AND THAT THE CYTOKINE TNF-ALPHA SEEMS TO BE A KEY SIGNALLING MOLECULE IN THE METAPLASIA-DYSPLASIA-CARCINOMA SEQUENCE. SPECIFICALLY IT APPEARS THAT BOTH EPIGENETIC AND INHERITED GENETICS COOPERATE TO MODULATE THE PROGNOSIS. 2011 20 4984 25 PATHWAYS OF GASTRIC CARCINOGENESIS, HELICOBACTER PYLORI VIRULENCE AND INTERACTIONS WITH ANTIOXIDANT SYSTEMS, VITAMIN C AND PHYTOCHEMICALS. HELICOBACTER PYLORI IS A CLASS ONE CARCINOGEN WHICH CAUSES CHRONIC ATROPHIC GASTRITIS, GASTRIC INTESTINAL METAPLASIA, DYSPLASIA AND ADENOCARCINOMA. THE MECHANISMS BY WHICH H. PYLORI INTERACTS WITH OTHER RISK AND PROTECTIVE FACTORS, PARTICULARLY VITAMIN C IN GASTRIC CARCINOGENESIS ARE COMPLEX. GASTRIC CARCINOGENESIS INCLUDES METABOLIC, ENVIRONMENTAL, EPIGENETIC, GENOMIC, INFECTIVE, INFLAMMATORY AND ONCOGENIC PATHWAYS. THE MOLECULAR CLASSIFICATION OF GASTRIC CANCER SUBTYPES HAS REVOLUTIONIZED THE UNDERSTANDING OF GASTRIC CARCINOGENESIS. THIS INCLUDES THE TUMOUR MICROENVIRONMENT, GERMLINE MUTATIONS, AND THE ROLE OF HELICOBACTER PYLORI BACTERIA, EPSTEIN BARR VIRUS AND EPIGENETICS IN SOMATIC MUTATIONS. THERE IS EVIDENCE THAT ASCORBIC ACID, PHYTOCHEMICALS AND ENDOGENOUS ANTIOXIDANT SYSTEMS CAN MODIFY THE RISK OF GASTRIC CANCER. GASTRIC JUICE ASCORBATE LEVELS DEPEND ON DIETARY INTAKE OF ASCORBIC ACID BUT CAN ALSO BE DECREASED BY H. PYLORI INFECTION, H. PYLORI CAGA SECRETION, TOBACCO SMOKING, ACHLORHYDRIA AND CHRONIC ATROPHIC GASTRITIS. ASCORBIC ACID MAY BE PROTECTIVE AGAINST GASTRIC CANCER BY ITS ANTIOXIDANT EFFECT IN GASTRIC CYTOPROTECTION, REGENERATING ACTIVE VITAMIN E AND GLUTATHIONE, INHIBITING ENDOGENOUS N-NITROSATION, REDUCING TOXIC EFFECTS OF INGESTED NITROSODIMETHYLAMINES AND HETEROCYCLIC AMINES, AND PREVENTING H. PYLORI INFECTION. THE EFFECTIVENESS OF SUCH CYTOPROTECTION IS RELATED TO H. PYLORI STRAIN VIRULENCE, PARTICULARLY CAGA EXPRESSION. THE ROLE OF VITAMIN C IN EPIGENETIC REPROGRAMMING IN GASTRIC CANCER IS STILL EVOLVING. OTHER FACTORS IN CONJUNCTION WITH VITAMIN C ALSO PLAY A ROLE IN GASTRIC CARCINOGENESIS. ERADICATION OF H. PYLORI MAY LEAD TO RECOVERY OF VITAMIN C SECRETION BY GASTRIC EPITHELIUM AND ENABLE REGRESSION OF PREMALIGNANT GASTRIC LESIONS, THEREBY INTERRUPTING THE CORREA CASCADE OF GASTRIC CARCINOGENESIS. 2020