1 3222 112 HELICOBACTER PYLORI ASSOCIATED CHRONIC GASTRITIS, CLINICAL SYNDROMES, PRECANCEROUS LESIONS, AND PATHOGENESIS OF GASTRIC CANCER DEVELOPMENT. HELICOBACTER PYLORI (H. PYLORI) INFECTION IS WELL KNOWN TO BE ASSOCIATED WITH THE DEVELOPMENT OF PRECANCEROUS LESIONS SUCH AS CHRONIC ATROPHIC GASTRITIS (AG), OR GASTRIC INTESTINAL METAPLASIA (GIM), AND CANCER. VARIOUS MOLECULAR ALTERATIONS ARE IDENTIFIED NOT ONLY IN GASTRIC CANCER (GC) BUT ALSO IN PRECANCEROUS LESIONS. H. PYLORI TREATMENT SEEMS TO IMPROVE AG AND GIM, BUT STILL REMAINS CONTROVERSIAL. IN CONTRAST, MANY STUDIES, INCLUDING META-ANALYSIS, SHOW THAT H. PYLORI ERADICATION REDUCES GC. MOLECULAR MARKERS DETECTED BY GENETIC AND EPIGENETIC ALTERATIONS RELATED TO CARCINOGENESIS REVERSE FOLLOWING H. PYLORI ERADICATION. THIS INDICATES THAT THESE CHANGES MAY BE AN IMPORTANT FACTOR IN THE IDENTIFICATION OF HIGH RISK PATIENTS FOR CANCER DEVELOPMENT. PATIENTS WHO UNDERWENT ENDOSCOPIC TREATMENT OF GC ARE AT HIGH RISK FOR DEVELOPMENT OF METACHRONOUS GC. A RANDOMIZED CONTROLLED TRIAL FROM JAPAN CONCLUDED THAT PROPHYLACTIC ERADICATION OF H. PYLORI AFTER ENDOSCOPIC RESECTION SHOULD BE USED TO PREVENT THE DEVELOPMENT OF METACHRONOUS GC, BUT RECENT RETROSPECTIVE STUDIES DID NOT SHOW THE TENDENCY. PATIENTS WITH PRECANCEROUS LESIONS (MOLECULAR ALTERATIONS) THAT DO NOT REVERSE AFTER H. PYLORI TREATMENT, REPRESENT THE "POINT OF NO RETURN" AND MAY BE AT HIGH RISK FOR THE DEVELOPMENT OF GC. THEREFORE, EARLIER H. PYLORI ERADICATION SHOULD BE CONSIDERED FOR PREVENTING GC DEVELOPMENT PRIOR TO THE APPEARANCE OF PRECANCEROUS LESIONS. 2014 2 3232 30 HELICOBACTER PYLORI-INDUCED SIGNALING PATHWAYS CONTRIBUTE TO INTESTINAL METAPLASIA AND GASTRIC CARCINOGENESIS. HELICOBACTER PYLORI (H. PYLORI) INDUCES CHRONIC GASTRIC INFLAMMATION, ATROPHIC GASTRITIS, INTESTINAL METAPLASIA, AND CANCER. ALTHOUGH THE RISK OF GASTRIC CANCER INCREASES EXPONENTIALLY WITH THE EXTENT OF ATROPHIC GASTRITIS, THE PRECISE MECHANISMS OF GASTRIC CARCINOGENESIS HAVE NOT BEEN FULLY ELUCIDATED. H. PYLORI INDUCES GENETIC AND EPIGENETIC CHANGES IN GASTRIC EPITHELIAL CELLS THROUGH ACTIVATING INTRACELLULAR SIGNALING PATHWAYS IN A CAGPAI-DEPENDENT MANNER. H. PYLORI EVENTUALLY INDUCES GASTRIC CANCER WITH CHROMOSOMAL INSTABILITY (CIN) OR MICROSATELLITE INSTABILITY (MSI), WHICH ARE CLASSIFIED AS TWO MAJOR SUBTYPES OF GASTRIC CANCER. ELUCIDATION OF THE PRECISE MECHANISMS OF GASTRIC CARCINOGENESIS WILL ALSO BE IMPORTANT FOR CANCER THERAPY. 2015 3 2895 38 GASTRIC CANCER DEVELOPMENT AFTER THE SUCCESSFUL ERADICATION OF HELICOBACTER PYLORI. GASTRIC CANCER (GC) DEVELOPS AS A RESULT OF INFLAMMATION-ASSOCIATED CARCINOGENESIS DUE TO HELICOBACTER PYLORI (H. PYLORI) INFECTION AND SUBSEQUENT DEFECTS IN GENETIC/EPIGENETIC EVENTS. ALTHOUGH THE INDICATION FOR ERADICATION THERAPY HAS BECOME WIDESPREAD, CLINICAL STUDIES HAVE REVEALED ITS LIMITED EFFECTS IN DECREASING THE INCIDENCE OF GC. MOREOVER, RESEARCH ON BIOPSY SPECIMENS OBTAINED BY CONVENTIONAL ENDOSCOPY HAS DEMONSTRATED THE FEASIBILITY OF THE RESTORATION OF SOME GENETIC/EPIGENETIC ALTERATIONS IN THE GASTRIC MUCOSA. PRACTICALLY, THE NUMBER OF SPORADIC CASES OF PRIMARY/METACHRONOUS GC THAT EMERGE AFTER SUCCESSFUL ERADICATION HAS INCREASED, WHILE ON-GOING GUIDELINES RECOMMEND ERADICATION THERAPY FOR PATIENTS WITH CHRONIC GASTRITIS AND THOSE WITH BACKGROUND MUCOSA AFTER ENDOSCOPIC RESECTION FOR GC. ACCORDINGLY, REGULAR SURVEILLANCE OF NUMEROUS INDIVIDUALS WHO HAVE RECEIVED ERADICATION THERAPY IS RECOMMENDED DESPITE THE LACK OF BIOMARKERS. RECENTLY, THE FOCUS HAS BEEN ON FUNCTIONAL REVERSIBILITY AFTER SUCCESSFUL ERADICATION AS ANOTHER CUE TO ELUCIDATE THE MECHANISMS OF RESTORATION AS WELL AS THOSE OF CARCINOGENESIS IN THE GASTRIC MUCOSA AFTER H. PYLORI ERADICATION. WE DEMONSTRATED THAT CONGO-RED CHROMOENDOSCOPY ENABLED THE IDENTIFICATION OF THE MULTI-FOCAL DISTRIBUTION OF FUNCTIONALLY IRREVERSIBLE MUCOSA COMPARED WITH THAT OF RESTORED MUCOSA AFTER SUCCESSFUL ERADICATION IN INDIVIDUALS AT EXTREMELY HIGH RISK FOR GC. FURTHER RESEARCH THAT USES FUNCTIONAL IMAGING MAY PROVIDE NEW INSIGHTS INTO THE MECHANISMS OF REGENERATION AND CARCINOGENESIS IN THE GASTRIC MUCOSA POST-ERADICATION AND MAY ALLOW FOR THE DEVELOPMENT OF USEFUL BIOMARKERS. 2016 4 762 44 CAUSAL ROLE OF HELICOBACTER PYLORI INFECTION AND ERADICATION THERAPY IN GASTRIC CARCINOGENESIS. MANY EPIDEMIOLOGICAL REPORTS INDICATE THAT HELICOBACTER PYLORI (H PYLORI) INFECTION PLAYS AN IMPORTANT ROLE IN GASTRIC CARCINOGENESIS. SEVERAL GENETIC AND EPIGENETIC ALTERATIONS CONTRIBUTE TO THE INITIATION, PROMOTION, AND PROGRESSION OF THE CANCER CELLS IN A MULTI-STEP MANNER. H PYLORI IS KNOWN TO INDUCE CHRONIC INFLAMMATION IN THE GASTRIC MUCOSA. ITS PRODUCTS, INCLUDING SUPEROXIDES, PARTICIPATE IN THE DNA DAMAGE FOLLOWED BY INITIATION, AND THE INFLAMMATION-DERIVED CYTOKINES AND GROWTH FACTORS CONTRIBUTE TO THE PROMOTION OF GASTRIC CARCINOGENESIS. BY ERADICATING H PYLORI, GASTRIC INFLAMMATION CAN BE CURED; THE THERAPY DIMINISHES THE LEVELS NOT ONLY OF INFLAMMATORY CELL INFILTRATION, BUT ALSO ATROPHY/INTESTINAL METAPLASIA IN PART. A RANDOMIZED CONTROLLED TRIAL REVEALED THAT THE ERADICATION THERAPY DIMINISHED THE GASTRIC CANCER PREVALENCE IN CASES WITHOUT PRE-CANCEROUS CONDITIONS. IN ADDITION, RECENT EPIDEMIOLOGICAL STUDIES FROM JAPANESE GROUPS DEMONSTRATED THAT THE DEVELOPMENT OF GASTRIC CANCER, ESPECIALLY OF THE INTESTINAL TYPE, WAS DECREASED BY SUCCESSFUL ERADICATION THERAPY, ALTHOUGH THESE WERE DESIGNED IN A NON-RANDOMIZED MANNER. HOWEVER, IT SHOULD BE MENTIONED THAT ENDOSCOPIC DETECTION IS THE ONLY WAY TO EVALUATE THE DEGREE OF GASTRIC CARCINOGENESIS. WE HAVE REPORTED THAT THE ENDOSCOPIC AND HISTOLOGICAL MORPHOLOGIES COULD BE MODIFIED BY ERADICATION THERAPY AND IT MIGHT CONTRIBUTE TO THE PREVALENCE OF GASTRIC CANCER DEVELOPMENT. CONSIDERING THE BIOLOGICAL NATURE OF CANCER CELL PROLIFERATION, IT IS CONSIDERED THAT A SUFFICIENTLY LONG-TERM FOLLOW-UP WOULD BE ESSENTIAL TO DISCUSS THE ANTICANCER EFFECT OF ERADICATION THERAPY. 2006 5 3229 32 HELICOBACTER PYLORI-INDUCED GASTRIC INFLAMMATION AND GASTRIC CANCER. HELICOBACTER PYLORI (H. PYLORI) INFECT OVER HALF OF THE WORLD'S POPULATION. THE PREVALENCE OF H. PYLORI INFECTION AND THE PREDOMINANT GENOTYPE OF H. PYLORI VIRULENCE FACTORS VARY CONSIDERABLY ACROSS DIFFERENT GEOGRAPHICAL REGIONS. H. PYLORI COULD UNIQUELY PERSIST FOR DECADES IN THE HARSH STOMACH ENVIRONMENT, WHERE IT DAMAGES THE GASTRIC MUCOSA AND CHANGES THE PATTERN OF GASTRIC HORMONE RELEASE, THEREBY AFFECTS GASTRIC PHYSIOLOGY. BY UTILIZING VARIOUS VIRULENCE FACTORS, H. PYLORI TARGETS DIFFERENT CELLULAR PROTEINS TO MODULATE THE HOST INFLAMMATORY RESPONSE AND INITIATE MULTIPLE "HITS" ON THE GASTRIC MUCOSA, RESULTING IN CHRONIC GASTRITIS AND PEPTIC ULCERATION. AMONG THE LONG-TERM CONSEQUENCES OF H. PYLORI INFECTION IS GASTRIC MALIGNANCIES, PARTICULARLY GASTRIC CANCER (GC) AND GASTRIC MUCOSA-ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMA. AS SUCH, H. PYLORI HAS BEEN RECOGNIZED AS A CLASS I CARCINOGEN BY THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER. DESPITE A CLOSE CAUSAL LINK BETWEEN H. PYLORI INFECTION AND THE DEVELOPMENT OF GASTRIC MALIGNANCIES, THE PRECISE MECHANISMS INVOLVED IN THIS PROCESS ARE STILL OBSCURE. STUDIES OVER THE PAST TWO DECADES HAVE REVEALED THAT H. PYLORI EXERT ONCOGENIC EFFECTS ON GASTRIC MUCOSA THROUGH A COMPLEX INTERACTION BETWEEN BACTERIAL FACTORS, HOST FACTORS, AND ENVIRONMENTAL FACTORS. NUMEROUS SIGNALING PATHWAYS CAN BE ACTIVATED BY H. PYLORI. IN THIS REVIEW, WE AIM TO ELABORATE ON THE RECENT DEVELOPMENTS IN THE PATHOPHYSIOLOGICAL MECHANISMS OF H. PYLORI-INDUCED GASTRIC INFLAMMATION AND GASTRIC CANCER. 2014 6 4984 37 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 7 5181 38 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 8 3230 42 HELICOBACTER PYLORI-INDUCED INFLAMMATION AND EPIGENETIC CHANGES DURING GASTRIC CARCINOGENESIS. THE SEQUENCE OF EVENTS ASSOCIATED WITH THE DEVELOPMENT OF GASTRIC CANCER HAS BEEN DESCRIBED AS "THE GASTRIC PRECANCEROUS CASCADE". THIS CASCADE IS A DYNAMIC PROCESS THAT INCLUDES LESIONS, SUCH AS ATROPHIC GASTRITIS, INTESTINAL METAPLASIA AND DYSPLASIA. ACCORDING TO THIS MODEL, HELICOBACTER PYLORI (H. PYLORI) INFECTION TARGETS THE NORMAL GASTRIC MUCOSA CAUSING NON-ATROPHIC GASTRITIS, AN INITIATING LESION THAT CAN BE CURED BY CLEARING H. PYLORI WITH ANTIBIOTICS OR THAT MAY THEN LINGER IN THE CASE OF CHRONIC INFECTION AND PROGRESS TO ATROPHIC GASTRITIS. THE PRESENCE OF VIRULENCE FACTORS IN THE INFECTING H. PYLORI DRIVES THE CARCINOGENESIS PROCESS. INDEPENDENT EPIDEMIOLOGICAL AND ANIMAL STUDIES HAVE CONFIRMED THE SEQUENTIAL PROGRESSION OF THESE PRECANCEROUS LESIONS. PARTICULARLY LONG-TERM FOLLOW-UP STUDIES ESTIMATED A RISK OF 0.1% FOR ATROPHIC GASTRITIS/INTESTINAL METAPLASIA AND 6% IN CASE OF DYSPLASIA FOR THE LONG-TERM DEVELOPMENT OF GASTRIC CANCER. WITH THIS IN MIND, A BETTER UNDERSTANDING OF THE GENETIC AND EPIGENETIC CHANGES ASSOCIATED WITH PROGRESSION OF THE CASCADE IS CRITICAL IN DETERMINING THE RISK OF GASTRIC CANCER ASSOCIATED WITH H. PYLORI INFECTION. IN THIS REVIEW, WE WILL SUMMARIZE SOME OF THE MOST RELEVANT MECHANISMS AND FOCUS PREDOMINANTLY BUT NOT EXCLUSIVELY ON THE DISCUSSION OF GENE PROMOTER METHYLATION AND MIRNAS IN THIS CONTEXT. 2015 9 4436 22 MOLECULAR EVOLUTION OF CHRONIC MYELOID LEUKAEMIA. CHRONIC MYELOID LEUKAEMIA (CML) IS A CLONAL DISORDER OF THE PLURIPOTENT HAEMATOPOIETIC STEM CELL. THE TYPICAL TRIPHASIC COURSE OF CML STARTS WITH THE PREMALIGNANT CHRONIC PHASE INITIATED BY BCR-ABL HYBRID ONCOGENE FORMATION. SECONDARY GENETIC AND EPIGENETIC ABERRATIONS ACCOMPANY THE PROGRESSION TO THE ACCELERATED PHASE AND FATAL BLASTIC CRISIS. PROPERLY TIMED BONE MARROW TRANSPLANTATION IN ELIGIBLE PATIENTS CAN RESULT IN DURABLE REMISSIONS OR CURE. BOTH OF THESE STATES ARE OFTEN ACCOMPANIED BY A LONG-TERM PERSISTENCE OF QUIESCENT LEUKAEMIC CELLS. ACCORDINGLY, A "FUNCTIONAL CURE" (I.E. TUMOUR DORMANCY INDUCTION), RATHER THAN COMPLETE ERADICATION OF THE MALIGNANT CELLS, IS AN ADEQUATE THERAPEUTICAL GOAL. THE LEVEL OF THE RESIDUAL BCR-ABL-POSITIVE CLONES SHOULD BE MONITORED AND SALVAGE TREATMENT INITIATED WHENEVER THESE QUIESCENT LEUKAEMIC CELLS EXIT THEIR DORMANT STATE. 2001 10 4960 44 PATHOGENESIS OF PRE-NEOPLASTIC LESIONS OF THE STOMACH: TARGETS FOR PREVENTION. GASTRIC ATROPHY AND INTESTINAL METAPLASIA ARE GENERALLY CONSIDERED TO BE PRECANCEROUS LESIONS OF THE STOMACH. CHRONIC HELICOBACTER PYLORI INFECTION IS ONE THE MOST IMPORTANT FACTORS IN THE DEVELOPMENT OF THESE PRE-MALIGNANT GASTRIC LESIONS. IN ADDITION TO BACTERIAL FACTORS, POLYMORPHISMS IN THE CYTOKINE GENES OF THE HOST THAT MODULATE INFLAMMATORY RESPONSES ARE FOUND TO HAVE A SYNERGISTIC EFFECT IN THE DEVELOPMENT OF GASTRIC CANCER AS WELL AS PRE-NEOPLASTIC LESIONS. RECENTLY, INAPPROPRIATE ACTIVATION OF THE INTESTINE-SPECIFIC TRANSCRIPTION FACTOR LIKE THE HOMEOBOX GENE COMPLEX CDX1 AND CDX2 ARE FOUND TO BE AN IMPORTANT CONTRIBUTING FACTOR IN THE INDUCTION OF INTESTINAL METAPLASIA IN THE STOMACH. ABERRANT EXPRESSION OF CYCLOOXYGENASE-2 AND EPIGENETIC CHANGES ARE ALSO FREQUENTLY DETECTED IN PRE-NEOPLASTIC GASTRIC LESIONS. ONE OF THE MOST IMPORTANT QUESTIONS RELATING TO THESE PRE-NEOPLASTIC GASTRIC LESIONS IS THAT WHETHER H. PYLORI ERADICATION COULD REVERSE THESE CHANGES. HOWEVER, MOST CONTROLLED STUDIES SHOWED NO OR JUST MODEST IMPROVEMENT IN INTESTINAL METAPLASIA AFTER H. PYLORI ERADICATION. FURTHER STUDIES SHOULD EVALUATE THE ROLE OF OTHER CHEMOPREVENTIVE AGENTS, PARTICULARLY CYCLOOXYGENASE-2 INHIBITOR, ON REGRESSION OF PRE-NEOPLASTIC LESIONS. 2004 11 5180 30 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 12 1042 28 CLINICAL AND MOLECULAR BASIS OF HEPATOCELLULAR CARCINOMA AFTER HEPATITIS C VIRUS ERADICATION. HEPATOCELLULAR CARCINOMA (HCC) ARISES IN THE BACKGROUND OF CHRONIC LIVER DISEASES, INCLUDING HEPATITIS AND LIVER CIRRHOSIS CAUSED BY HEPATITIS C VIRUS (HCV) INFECTION. IT IS WELL KNOWN THAT HCV ERADICATION USING ANTIVIRAL DRUGS CAN EFFICIENTLY INHIBIT HEPATOCARCINOGENESIS. RECENT ADVANCES IN AND DEVELOPMENT OF DIRECT-ACTING ANTIVIRAL (DAA) DRUGS HAS REVOLUTIONIZED THE TREATMENT OF HCV INFECTION, AND THE VAST MAJORITY OF HCV PATIENTS CAN ACHIEVE HCV ERADICATION USING DAAS. HOWEVER, MOUNTING EVIDENCE CLEARLY INDICATES THAT HCC INEVITABLY OCCURS IN A SUBSET OF PATIENTS AFTER SUCCESSFUL VIRAL ERADICATION USING DAA THERAPY. CANCER IS A GENETIC DISEASE, AND THE ACCUMULATION OF GENETIC AND EPIGENETIC ABERRATIONS MAY CAUSE HEPATOCARCINOGENESIS IN CHRONICALLY DAMAGED LIVER, EVEN AFTER VIRUS ELIMINATION. IN THIS REVIEW, WE HIGHLIGHT HCC DEVELOPMENT AFTER HCV ERADICATION AND DISCUSS THE CURRENT UNDERSTANDING OF THE MOLECULAR MECHANISMS OF TUMORIGENESIS AFTER VIRUS ELIMINATION, FOCUSING ON THE GENETIC AND EPIGENETIC BACKGROUND OF CHRONICALLY DAMAGED LIVER TISSUES. 2022 13 3134 47 GLOBAL DNA HYPOMETHYLATION IS AN EARLY EVENT IN HELICOBACTER PYLORI-RELATED GASTRIC CARCINOGENESIS. AIM: CANCER, PARTICULARLY GASTRIC CANCER (GC), IS PREVALENTLY AN EPIGENETIC PHENOMENON THAT IS DEPENDENT ON AN ALTERED DNA METHYLATION PATTERN. IN GASTRIC CARCINOGENESIS, MANY GENES SHOW ABERRANT METHYLATION; HOWEVER, NONE OF THEM MAY BE USED AS A BIOMARKER OF CANCER RISK AND PROGRESSION. THE AUTHORS AIMED TO EVALUATE THE GLOBAL DNA METHYLATION OF GASTRIC MUCOSA IN HELICOBACTER PYLORI (HP)-RELATED CHRONIC GASTRITIS, IN GC AND IN 10 PATIENTS WITH PRENEOPLASTIC LESIONS (IE, ATROPHY AND INTESTINAL METAPLASIA) FOLLOWED UP FOR 10 YEARS. METHODS: THE AUTHORS ANALYSED 93 DYSPEPTIC PATIENTS WHO UNDERWENT UPPER ENDOSCOPY, 41 SURGICAL GC SAMPLES AND 10 PATIENTS WITH PRENEOPLASTIC GASTRIC LESIONS FOLLOWED UP FOR 10 YEARS AFTER SUCCESSFUL HP ERADICATION THERAPY. GLOBAL DNA METHYLATION STATUS AND SURROGATE MARKERS OF CELL PROLIFERATION AND APOPTOSIS WERE EVALUATED BY IMMUNOHISTOCHEMISTRY USING THE ANTI-5-METHYLCYTOSINE (5-MC), ANTI-KI-67 AND ANTI-P53 (ANTI-APOPTOTIC MARKER)-SPECIFIC ANTIBODIES, RESPECTIVELY. RESULTS: GLOBAL DNA METHYLATION OF GASTRIC MUCOSA GRADUALLY DECREASED FROM NORMAL MUCOSA TO HP-POSITIVE GASTRITIS, HP-POSITIVE CHRONIC ATROPHIC GASTRITIS, INDEPENDENT OF CAG-A STATUS AND GC; HOWEVER, THE VARIATION WAS SIGNIFICANT (P<0.05) ONLY BETWEEN HP-NEGATIVE SUBJECTS AND HP-POSITIVE CHRONIC GASTRITIS. INTERESTINGLY, THE 5-MC IMMUNOSTAINING WAS ABSENT IN AREAS OF INTESTINAL METAPLASIA. IN THE 10 PATIENTS WITH PRENEOPLASTIC LESIONS, GLOBAL DNA METHYLATION DECREASED OVER TIME DESPITE THE ERADICATION OF HP INFECTION, BUT REACHED SIGNIFICANCE ONLY AT 10 YEARS VERSUS BASELINE. THE 5-MC IMMUNOSTAINING NEGATIVELY CORRELATED WITH KI-67 AND P53 EXPRESSION IN ALL GROUPS. CONCLUSION: GLOBAL DNA HYPOMETHYLATION IS AN EARLY MOLECULAR EVENT IN HP-RELATED GASTRIC CARCINOGENESIS. FURTHER STUDIES WITH MORE CASES AND A LONGER FOLLOW-UP ARE NEEDED TO ESTABLISH THE POTENTIAL GC PREDICTIVE ROLE OF DNA HYPOMETHYLATION. 2011 14 3226 33 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 15 1830 45 EFFECTS OF LONG-TERM ASPIRIN USE ON MOLECULAR ALTERATIONS IN PRECANCEROUS GASTRIC MUCOSA IN PATIENTS WITH AND WITHOUT GASTRIC CANCER. THE RISK OF GASTRIC CANCER (GC) REMAINS EVEN AFTER H. PYLORI ERADICATION; THUS, OTHER COMBINATION TREATMENTS, SUCH AS CHEMOPREVENTIVE DRUGS, ARE NEEDED. WE EVALUATED THE EFFECTS OF ASPIRIN ON GENETIC/EPIGENETIC ALTERATIONS IN PRECANCEROUS CONDITIONS, I.E., ATROPHIC MUCOSA (AM) AND INTESTINAL METAPLASIA (IM), IN PATIENTS WITH CHRONIC GASTRITIS WHO HAD TAKEN ASPIRIN FOR MORE THAN 3 YEARS. A TOTAL OF 221 BIOPSY SPECIMENS FROM 74 PATIENTS, INCLUDING ATROPHIC GASTRITIS (AG) CASES WITHOUT ASPIRIN USE (CONTROL), AG CASES WITH ASPIRIN USE (AG GROUP), AND GC CASES WITH ASPIRIN USE (GC GROUP), WERE ANALYZED. ASPIRIN USE WAS ASSOCIATED WITH A SIGNIFICANT REDUCTION OF CDH1 METHYLATION IN AM (OR: 0.15, 95% CI: 0.06-0.41, P = 0.0002), BUT WAS LESS EFFECTIVE IN REVERSING THE METHYLATION THAT OCCURRED IN IM. FREQUENT HYPERMETHYLATION INCLUDING THAT OF CDH1 IN AM INCREASED IN THE GC GROUP COMPARED TO THE AG GROUP, AND CDH1 METHYLATION WAS AN INDEPENDENT PREDICTIVE MARKER OF GC (OR: 8.50, 95% CI: 2.64-25.33, P = 0.0003). IN PATIENTS WITH LONG-TERM ASPIRIN USE, THE CHANGES OF MOLECULAR EVENTS IN AM BUT NOT IM MAY BE AN IMPORTANT FACTOR IN THE REDUCTION OF CANCER INCIDENCE. IN ADDITION, METHYLATION OF THE CDH1 GENE IN AM MAY BE A SURROGATE OF GC. 2017 16 1056 37 CLINICAL MANIFESTATIONS AND EPIGENETIC MECHANISMS OF GASTRIC MUCOSA ASSOCIATED LYMPHOID TISSUE LYMPHOMA AND LONG-TERM FOLLOW-UP FOLLOWING HELICOBACTER PYLORI ERADICATION. THE CURRENT STUDY AIMED TO SUMMARIZE THE CLINICAL MANIFESTATIONS AND IDENTIFY THE EPIGENETIC MECHANISMS OF GASTRIC MUCOSA ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMA, AS WELL AS EVALUATE THE LONG-TERM EFFECTS OF HELICOBACTER PYLORI (H. PYLORI) ERADICATION. A TOTAL OF 122 PATIENTS WITH MARGINAL ZONE B-CELL LYMPHOMA OF PRIMARY GASTRIC MALT LYMPHOMA WERE ENROLLED IN THE PRESENT STUDY. THE CLINICAL MANIFESTATIONS OF GASTRIC MALT LYMPHOMA, INCLUDING SYMPTOMS, H. PYLORI STATE AND ENDOSCOPIC TYPE, WERE SUMMARIZED. THE RESPONSE TO THERAPY WAS EVALUATED IN PATIENTS THAT UNDERWENT H. PYLORI ERADICATION. SURVIVAL ANALYSIS WAS ESTIMATED USING THE KAPLAN-MEIER METHOD. THE EXPRESSION OF MICRORNA-383 (MIR-383) IN TUMOR TISSUES AND CELL LINES WAS DETERMINED USING REVERSE TRANSCRIPTION QUANTITATIVE POLYMERASE CHAIN REACTION. FURTHERMORE, BIOINFORMATIC ANALYSES, LUCIFERASE REPORTER ASSAYS. AND WESTERN BLOT ANALYSIS IDENTIFIED ZINC FINGER E-BOX BINDING HOMEOBOX 2 (ZEB2) AS A DIRECT TARGET GENE OF MIR-383. AN MTT ASSAY WAS USED TO EXAMINE THE FUNCTION OF MIR-383 AND ZEB2 IN MALT LYMPHOMA. THE CLINICAL SYMPTOMS OF PATIENTS WITH GASTRIC MALT LYMPHOMA WERE NON-SPECIFIC AND INCLUDED EPIGASTRIC PAIN, ABDOMINAL DISCOMFORT AND BLEEDING. THE MAJORITY OF ENDOSCOPIC TYPES WERE CLASSIFIED AS ULCER, EROSION AND MUCOSA EDEMA. THE H. PYLORI INFECTION RATE WAS 79.5% (97/122) AND A TOTAL OF 47 PATIENTS UNDERWENT ERADICATION THERAPY. LYMPHOMA REMISSION WAS ACHIEVED IN 93.6% (44/47) OF PATIENTS AND COMPLETE REMISSION (CR) WAS ACHIEVED IN 74.4% (35/47). THE MEDIAN FOLLOW-UP TIME WAS 38 MONTHS (RANGE, 10-132 MONTHS) AND THE MEDIAN TIME TAKEN TO ACHIEVE CR WAS 4 MONTHS (RANGE, 3-7 MONTHS). THE ESTIMATED 3-YEAR SURVIVAL RATE WAS 90.3% AND THE 5-YEAR SURVIVAL RATE WAS 76.2%. THEREFORE, IT WAS DETERMINED THAT PATIENTS WITH STAGE I OR II GASTRIC MALT LYMPHOMA ARE ABLE TO UNDERGO H. PYLORI ERADICATION AS A FIRST-LINE TREATMENT AND THAT THE SURVIVAL RATE OF PATIENTS UNDERGOING THIS TREATMENT IS HIGH. FURTHERMORE, IT WAS DETERMINED THAT THE MECHANISM BY WHICH MIR-383 AND ZEB2 CONTRIBUTE TO MALT LYMPHOMA PROGRESSION IS BY THE TARGETING OF ZEB2 BY MIR-383, WHICH INHIBITS THE PROLIFERATION OF CANCER CELLS. 2018 17 6841 39 [MECHANISMS OF H. PYLORI INFECTION-INDUCED GASTRIC CARCINOGENESIS]. MANY EPIDEMIOLOGICAL STUDIES HAVE DEMONSTRATED A STRONG ASSOCIATION BETWEEN H. PYLORI (HELICOBACTER PYLORI) INFECTION AND HUMAN GASTRIC CANCER DEVELOPMENT. THE PRECISE MECHANISMS ACCOUNTING FOR GASTRIC CANCER DEVELOPMENT INDUCED BY H. PYLORI INFECTION ARE STILL NOT COMPLETELY UNDERSTOOD. HOWEVER, IT SHOULD BE REASONABLE TO ASSUME THAT THERE ARE TWO DISTINCT MOLECULAR PATHWAYS FOR GASTRIC CARCINOGENESIS BY H. PYLORI INFECTION; THE DIRECT ACTION OF THE BACTERIA ITSELF ON GASTRIC EPITHELIAL CELLS, AND THE ACCUMULATION OF GENETIC CHANGES CAUSED BY PROLONGED BACTERIAL INFECTION AND CHRONIC INFLAMMATION. AS A DIRECT ACTION OF H. PYLORI, BACTERIAL PROTEINS SUCH AS CAGA COULD BE DELIVERED INTO GASTRIC EPITHELIAL CELLS VIA THE TYPE IV SECRETION APPARATUS AND MODIFY THE HOST CELL FUNCTIONS RELATED TO CELL PROLIFERATION. IN ADDITION TO THE DIRECT BACTERIAL ACTION, H. PYLORI INFECTION AND THE RESULTANT INFLAMMATORY RESPONSE CAUSE VARIOUS GENETIC AND EPIGENETIC CHANGES IN TUMOR-RELATED GENES OF THE GASTRIC EPITHELIAL CELLS. NOTABLY, EXPRESSION OF AID (ACTIVATION-INDUCED CYTIDINE DEAMINASE), A DNA EDITING ENZYME THAT UNDERGOES SOMATIC HYPERMUTATION ON HUMAN GENES, IS INDUCED IN RESPONSE TO H. PYLORI INFECTION AND PROINFLAMMATORY CYTOKINE STIMULATION IN HUMAN GASTRIC EPITHELIAL CELLS. AS A RESULT, THE ACCUMULATION OF GENETIC ALTERATIONS WOULD PERSIST UNTIL THE CLINICAL STAGE OF ATROPHIC GASTRITIS AND EVENTUALLY TRIGGER THE MALIGNANT TRANSFORMATION OF GASTRIC CELLS. 2010 18 4751 45 NOVEL RISK MARKERS FOR GASTRIC CANCER SCREENING: PRESENT STATUS AND FUTURE PROSPECTS. INITIAL IDENTIFICATION OF POPULATIONS AT HIGH RISK OF GASTRIC CANCER (GC) IS IMPORTANT FOR ENDOSCOPIC SCREENING OF GC. AS SERUM PEPSINOGEN (PG) TEST-POSITIVE SUBJECTS WITH PROGRESSION OF CHRONIC ATROPHIC GASTRITIS (CAG) SHOW A HIGH LIKELIHOOD OF FUTURE CANCER DEVELOPMENT, THIS POPULATION WARRANTS CAREFUL FOLLOW-UP OBSERVATION AS A HIGH-RISK GC GROUP. BY COMBINING THE PG TEST WITH HELICOBACTER PYLORI (HP) ANTIBODY TITERS, THE HP-RELATED CHRONIC GASTRITIS STAGE CAN BE CLASSIFIED, THUS IDENTIFYING NOT ONLY A GC HIGH-RISK GROUP BUT ALSO A LOW-RISK GROUP. AMONG PG TEST-NEGATIVE PATIENTS WITHOUT CAG, THOSE WITH HIGH SERUM PG II LEVELS AND HP ANTIBODY TITERS ARE THOUGHT TO HAVE SEVERE GASTRIC MUCOSAL INFLAMMATION AND THE RISK OF DIFFUSE-TYPE GC IS ALSO HIGH. MEANWHILE, IN GASTRIC MUCOSAE OBTAINED BY ENDOSCOPIC BIOPSY, HP INFECTION INDUCES ABERRANT DNA METHYLATION IN CPG ISLANDS IN MULTIPLE GENE REGIONS AND THE EXTENT OF METHYLATION CLEARLY CORRELATES WITH GC RISK. BY QUANTIFYING ABERRANT DNA METHYLATION IN SUITABLE GENE MARKERS, WE CAN DETERMINE THE EXTENT OF THE EPIGENETIC FIELD FOR CANCERIZATION. THESE NOVEL CONCEPTS AND RISK MARKERS WILL HAVE MANY CLINICAL APPLICATIONS IN GASTROINTESTINAL ENDOSCOPY, INCLUDING MORE EFFICIENT ENDOSCOPIC GC SCREENING AND A STRATEGIC APPROACH TO METACHRONOUS MULTIPLE GCS AFTER ENDOSCOPIC TREATMENT. 2010 19 3221 29 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 20 1797 46 EFFECT OF HELICOBACTER PYLORI ERADICATION ON GASTRIC PRECANCEROUS LESIONS: A SYSTEMATIC REVIEW AND META-ANALYSIS. BACKGROUND: THE QUESTION OF WHETHER ERADICATION OF HELICOBACTER PYLORI (HP) CAN REVERSE GASTRIC PRECANCEROUS LESIONS, INCLUDING INTESTINAL METAPLASIA, REMAINS UNCERTAIN, LEADING TO ONGOING DEBATE. THEREFORE, A META-ANALYSIS WAS PERFORMED TO EVALUATE THE EFFECT OF HP ERADICATION ON GASTRIC PRECANCEROUS LESIONS. MATERIALS AND METHODS: PUBMED, EMBASE, COCHRANE LIBRARY, WEB OF SCIENCE, SCOPUS DATABASE, AND CLINICALTRIALS.GOV WERE SYSTEMATICALLY SEARCHED FROM INCEPTION TO APRIL 2023 FOR STUDIES THAT EXPLORED THE IMPACT OF HP ERADICATION ON GASTRIC PRECANCEROUS LESIONS. RISK RATIOS (RRS) AND THEIR 95% CONFIDENCE INTERVALS (95% CIS) WERE SELECTED AS THE EFFECT SIZE. WE USED THE RANDOM-EFFECTS MODEL TO ASSESS POOLED DATA. WE ALSO PERFORMED QUALITY ASSESSMENTS, SUBGROUP ANALYSES, AND SENSITIVITY ANALYSES. RESULTS: FIFTEEN STUDIES WERE INCLUDED. COMPARED WITH PLACEBO, HP ERADICATION COULD SIGNIFICANTLY PREVENT THE PROGRESSION OF GASTRIC PRECANCEROUS LESIONS (RR = 0.87, 95% CI: 0.81-0.94, P < 0.01) AND REVERSE THEM (RR = 1.32, 95% CI: 1.17-1.50, P < 0.01). THEN, SPECIFIC PRECANCEROUS LESIONS WERE FURTHER EXPLORED. THE PROGRESSION OF INTESTINAL METAPLASIA WAS SIGNIFICANTLY PREVENTED BY HP ERADICATION COMPARED TO PLACEBO OR NO TREATMENT (RR = 0.80, 95% CI: 0.69-0.94, P < 0.01). MOREOVER, COMPARED WITH PLACEBO OR NO TREATMENT, HP ERADICATION ALSO IMPROVED CHRONIC ATROPHIC GASTRITIS (RR = 1.84, 95% CI: 1.30-2.61, P < 0.01) AND INTESTINAL METAPLASIA (RR = 1.41, 95% CI: 1.15-1.73, P < 0.01). HOWEVER, IN TERMS OF PREVENTING DYSPLASIA PROGRESSION (RR = 0.86, 95% CI: 0.37-2.00) AND IMPROVING DYSPLASIA (RR = 0.89, 95% CI: 0.47-1.70), HP ERADICATION HAD NO ADVANTAGE COMPARED TO PLACEBO OR NO TREATMENT. CONCLUSIONS: HP ERADICATION THERAPY COULD PREVENT THE PROGRESSION OF GASTRIC PRECANCEROUS LESIONS AND REVERSE THEM. NOTABLY, INTESTINAL METAPLASIA CAN BE REVERSED, BUT THIS MAY ONLY BE APPROPRIATE FOR PATIENTS WITH EPIGENETIC ALTERATIONS AND MILDER LESIONS. 2023