1 2938 76 GENETIC AND EPIGENETIC ALTERATIONS IN BARRETT'S ESOPHAGUS AND ESOPHAGEAL ADENOCARCINOMA. ESOPHAGEAL ADENOCARCINOMA (EAC) DEVELOPS FROM BARRETT'S ESOPHAGUS (BE), WHEREIN NORMAL SQUAMOUS EPITHELIA IS REPLACED BY SPECIALIZED INTESTINAL METAPLASIA IN RESPONSE TO CHRONIC GASTROESOPHAGEAL ACID REFLUX. BE CAN PROGRESS TO LOW- AND HIGH-GRADE DYSPLASIA, INTRAMUCOSAL, AND INVASIVE CARCINOMA. BOTH BE AND EAC ARE CHARACTERIZED BY LOSS OF HETEROZYGOSITY, ANEUPLOIDY, SPECIFIC GENETIC MUTATIONS, AND CLONAL DIVERSITY. GIVEN THE LIMITATIONS OF HISTOPATHOLOGY, GENOMIC AND EPIGENOMIC ANALYSES MAY IMPROVE THE PRECISION OF RISK STRATIFICATION. ASSAYS TO DETECT MOLECULAR ALTERATIONS ASSOCIATED WITH NEOPLASTIC PROGRESSION COULD BE USED TO IMPROVE THE PATHOLOGIC ASSESSMENT OF BE/EAC AND TO SELECT HIGH-RISK PATIENTS FOR MORE INTENSIVE SURVEILLANCE. 2015 2 1975 27 EPIGENETIC ALTERATIONS FROM BARRETT'S ESOPHAGUS TO ESOPHAGEAL ADENOCARCINOMA. BARRETT'S ESOPHAGUS (BE) IS A DISEASE ENTITY THAT IS A SEQUELA OF CHRONIC GASTROESOPHAGEAL REFLUX DISEASE THAT MAY RESULT IN ESOPHAGEAL ADENOCARCINOMA (EAC) DUE TO COLUMNAR EPITHELIAL DYSPLASIA. THE HISTOLOGICAL DEGREE OF DYSPLASIA IS THE SOLE BIOMARKER FREQUENTLY UTILIZED BY CLINICIANS. HOWEVER, THE COST OF ENDOSCOPY AND THE FACT THAT THE DEGREE OF DYSPLASIA DOES NOT PROGRESS IN MANY PATIENTS WITH BE DIMINISH THE EFFECTIVENESS OF HISTOLOGICAL GRADING AS A PERFECT BIOMARKER. MULTIPLE OR MORE QUANTITATIVE BIOMARKERS ARE REQUIRED BY CLINICIANS SINCE EARLY DIAGNOSIS IS CRUCIAL IN ESOPHAGEAL ADENOCANCERS, WHICH HAVE A HIGH MORTALITY RATE. THE PRESENCE OF EPIGENETIC FACTORS IN THE EARLY STAGES OF THIS NEOPLASTIC TRANSFORMATION HOLDS PROMISE AS A PREDICTIVE BIOMARKER. IN THIS REVIEW, CURRENT STUDIES ON DNA METHYLATIONS, HISTONE MODIFICATIONS, AND NONCODING RNAS (MIRNAS) THAT HAVE BEEN DISCOVERED DURING THE PROGRESSION FROM BE DYSPLASIA TO EAC WERE COLLATED. 2023 3 563 42 BARRETT'S ESOPHAGUS: CAN BIOMARKERS PREDICT PROGRESSION TO MALIGNANCY? BARRETT'S ESOPHAGUS (BE) IS ONE OF THE MOST COMMON PREMALIGNANT LESIONS AND CAN PROGRESS TO ESOPHAGEAL ADENOCARCINOMA. IT IS CHARACTERIZED HISTOLOGICALLY BY A SPECIALIZED INTESTINAL METAPLASIA THAT REPLACES THE SQUAMOUS EPITHELIUM OF THE DISTAL ESOPHAGUS, AND IS ASSOCIATED WITH CHRONIC GASTROESOPHAGEAL REFLUX DISEASE AND OBESITY. SIMILAR TO THE ADENOMA-CARCINOMA SEQUENCE OF COLORECTAL CARCINOMAS, ESOPHAGEAL ADENOCARCINOMA DEVELOPS THROUGH PROGRESSION FROM BE TO LOW- AND HIGH-GRADE DYSPLASIA, THEN TO ADENOCARCINOMA WITH ACCUMULATION OF GENETIC AND EPIGENETIC ABNORMALITIES. THE EXACT MALIGNANCY POTENTIAL OF BE IS UNCERTAIN. DYSPLASIA IS THE MOST PREDICTIVE MARKER FOR RISK OF ESOPHAGEAL ADENOCARCINOMA, WHEREAS ENDOSCOPIC AND HISTOLOGICAL DIAGNOSES ARE STILL THE GOLD STANDARD FOR SURVEILLANCE OF PATIENTS WITH BE. HOWEVER, BOTH ARE LIMITED, EITHER BY SAMPLING ERRORS IN BIOPSIES OR BY DIFFERENCES IN HISTOLOGICAL INTERPRETATION. SEVERAL STUDIES HAVE IDENTIFIED CANDIDATE BIOMARKERS THAT MAY HAVE PREDICTIVE VALUE AND MAY SERVE AS ADDITIONAL FACTORS FOR THE RISK ASSESSMENT OF ESOPHAGEAL ADENOCARCINOMA. THIS REVIEW DISCUSSES THE ROLE OF BIOMARKERS IN THE PROGRESSION FROM BE TO ADENOCARCINOMA, FOCUSING ON CLINICAL AND MOLECULAR MARKERS. 2008 4 4437 50 MOLECULAR EVOLUTION OF METAPLASIA TO ADENOCARCINOMA IN THE ESOPHAGUS. ESOPHAGEAL ADENOCARCINOMA (EAC) DEVELOPS FROM BARRETT'S ESOPHAGUS (BE), A CONDITION WHERE THE NORMAL SQUAMOUS EPITHELIA IS REPLACED BY SPECIALIZED INTESTINAL METAPLASIA IN RESPONSE TO CHRONIC GASTROESOPHAGEAL ACID REFLUX. IN A MINORITY OF INDIVIDUALS, BE CAN PROGRESS TO LOW- AND HIGH-GRADE DYSPLASIA AND EVENTUALLY TO INTRA-MUCOSAL AND THEN INVASIVE CARCINOMA. BE PROVIDES RESEARCHERS WITH A UNIQUE MODEL TO CHARACTERIZE THE PROCESS BY WHICH A CARCINOMA ARISES FROM ITS PRECURSOR LESION. MOLECULAR STUDIES OF BE HAVE DEMONSTRATED THAT IT IS NOT SIMPLY A METAPLASTIC TISSUE, BUT RATHER IT HARBORS FREQUENT ALTERATIONS THAT ARE ALSO PRESENT IN DYSPLASTIC BE AND IN EAC. BOTH BE AND EAC ARE CHARACTERIZED BY LOSS OF HETEROZYGOSITY, ANEUPLOIDY, SPECIFIC GENETIC MUTATIONS, AND CLONAL DIVERSITY. EPIGENETIC ABNORMALITIES, PRIMARY ALTERATIONS IN DNA METHYLATION, ARE ALSO FREQUENTLY SEEN IN BE AND EAC. CANDIDATE GENE AND ARRAY-BASED APPROACHES HAVE DEMONSTRATED THAT NUMEROUS TUMOR SUPPRESSOR GENES EXHIBIT ABERRANT PROMOTER METHYLATION, AND SOME OF THESE ALTERED GENES ARE ASSOCIATED WITH THE NEOPLASTIC PROGRESSION OF BE. IT HAS ALSO BEEN SHOWN THAT THE BE AND EAC EPIGENOMES ARE CHARACTERIZED BY HYPOMETHYLATION OF INTRAGENIC AND NON-CODING REGIONS RECENT STUDIES HAVE ALSO PROVIDED NEW INSIGHT INTO THE EVOLUTIONARY FORCES UNDERLYING THE MOLECULAR ALTERATIONS SEEN IN BE AND EAC AND INTO THE MOLECULAR PATHOGENESIS OF EAC. 2018 5 2015 32 EPIGENETIC BIOMARKERS IN ESOPHAGEAL CANCER. THE ABERRANT DNA METHYLATION OF TUMOR SUPPRESSOR GENES IS WELL DOCUMENTED IN ESOPHAGEAL CANCER, INCLUDING ADENOCARCINOMA (EAC) AND SQUAMOUS CELL CARCINOMA (ESCC) AS WELL AS IN BARRETT'S ESOPHAGUS (BE), A PRE-MALIGNANT CONDITION THAT IS ASSOCIATED WITH CHRONIC ACID REFLUX. BE IS A WELL-RECOGNIZED RISK FACTOR FOR THE DEVELOPMENT OF EAC, AND CONSEQUENTLY THE STANDARD OF CARE IS FOR INDIVIDUALS WITH BE TO BE PLACED IN ENDOSCOPIC SURVEILLANCE PROGRAMS AIMED AT DETECTING EARLY HISTOLOGIC CHANGES THAT ASSOCIATE WITH AN INCREASED RISK OF DEVELOPING EAC. YET BECAUSE THE ABSOLUTE RISK OF EAC IN INDIVIDUALS WITH BE IS MINIMAL, A CLINICAL NEED IN THE MANAGEMENT OF BE IS THE IDENTIFICATION OF ADDITIONAL RISK MARKERS THAT WILL INDICATE INDIVIDUALS WHO ARE AT A SIGNIFICANT ABSOLUTE RISK OF EAC SO THAT THEY MAY BE SUBJECTED TO MORE INTENSIVE SURVEILLANCE. THE BEST CURRENTLY AVAILABLE RISK MARKER IS THE DEGREE OF DYSPLASIA IN ENDOSCOPIC BIOPSIES FROM THE ESOPHAGUS; HOWEVER, THIS MARKER IS SUBOPTIMAL FOR A VARIETY OF REASONS. TO DATE, THERE ARE NO MOLECULAR BIOMARKERS THAT HAVE BEEN TRANSLATED TO WIDESPREAD CLINICAL PRACTICE. THE SEARCH FOR BIOMARKERS, INCLUDING HYPERMETHYLATED GENES, FOR EITHER THE DIAGNOSIS OF BE, EAC, OR ESCC OR FOR RISK STRATIFICATION FOR THE DEVELOPMENT OF EAC IN THOSE WITH BE IS CURRENTLY AN AREA OF ACTIVE RESEARCH. IN THIS REVIEW, WE SUMMARIZE THE STATUS OF IDENTIFIED CANDIDATE EPIGENETIC BIOMARKERS FOR BE, EAC, AND ESCC. MOST OF THESE ABERRANTLY METHYLATED GENES HAVE BEEN DESCRIBED IN THE CONTEXT OF EARLY DETECTION OR DIAGNOSTIC MARKERS; OTHERS MIGHT PROVE USEFUL FOR ESTIMATING PROGNOSIS OR PREDICTING RESPONSE TO TREATMENT. FINALLY, SPECIAL ATTENTION WILL BE PAID TO SOME OF THE CHALLENGES THAT MUST BE OVERCOME IN ORDER TO DEVELOP CLINICALLY USEFUL ESOPHAGEAL CANCER BIOMARKERS. 2014 6 562 28 BARRETT ESOPHAGUS: HISTORY, DEFINITION AND ETIOPATHOGENY. THE INJURY OF THE ESOPHAGEAL EPITHELIUM MAY BE DETERMINED BY THE REFLUX OF THE GASTRIC ACID IN THE ESOPHAGUS. BARRETT'S ESOPHAGUS (BE) IS CHARACTERIZED BY THE REPLACEMENT OF THE NORMAL SQUAMOUS EPITHELIUM WITH THE COLUMNAR EPITHELIUM, WHEN THE HEALING OF THE LESION OCCURS. ACCORDING TO SOME STUDIES, THE INCIDENCE OF THE ESOPHAGEAL ADENOCARCINOMA IN PATIENTS WITH BE IS OF ABOUT 0,5% PER YEAR. THE TERM BARRETT'S ESOPHAGUS IS SUBJECTED TO INTERPRETATION NOWADAYS, SO IT LACKS THE CLARITY NEEDED FOR THE CLINICAL AND SCIENTIFIC COMMUNICATION ON THE SUBJECT OF COLUMNAR METAPLASIA OF THE ESOPHAGEAL MUCOSA. THE MAJOR PATHOGENETIC FACTOR IN THE DEVELOPMENT OF BE IS REPRESENTED BY THE REFLUX DISEASE. THE CELLULAR ORIGIN OF BE IS CONTROVERSIAL AND IT REPRESENTS AN ISSUE THAT NEEDS TO BE RESOLVED BECAUSE IT WILL HAVE IMPLICATIONS IN THE PUTATIVE MOLECULAR MECHANISMS UNDERLYING THE METAPLASTIC PROCESS. THE EPIGENETIC OR GENETIC CHANGES, WHICH ALTER PROTEIN EXPRESSION, FUNCTION, AND/ OR ACTIVITY, IN POST-MITOTIC CELLS TO DRIVE TRANSDIFFERENTIATION OR IN STEM/ PROGENITOR CELLS SUCH THAT THEY ARE REPROGRAMMED TO DIFFERENTIATE INTO COLUMNAR RATHER THAN SQUAMOUS CELLS, ARE DRIVEN BY THE INFLAMMATORY ENVIRONMENT CREATED BY CHRONIC REFLUX. IN ORDER TO BE ABLE TO DEVELOP BETTER THERAPEUTIC STRATEGIES FOR THE PATIENTS WITH THIS DISEASE, AN INCREASING INTEREST IN UNDERSTANDING THE PATHOGENESIS OF BE AT THE CELLULAR AND MOLECULAR LEVEL PRESENTS THESE DAYS. 2014 7 720 23 CALPAIN-14 AND ITS ASSOCIATION WITH EOSINOPHILIC ESOPHAGITIS. CALPAINS ARE A FAMILY OF INTRACELLULAR, CALCIUM-DEPENDENT CYSTEINE PROTEASES INVOLVED IN A VARIETY OF REGULATORY PROCESSES, INCLUDING CYTOSKELETAL DYNAMICS, CELL-CYCLE PROGRESSION, SIGNAL TRANSDUCTION, GENE EXPRESSION, AND APOPTOSIS. THESE ENZYMES HAVE BEEN IMPLICATED IN A NUMBER OF DISEASE PROCESSES, NOTABLY FOR THIS REVIEW INVOLVING EOSINOPHILIC TISSUE INFLAMMATION, SUCH AS EOSINOPHILIC ESOPHAGITIS (EOE), A CHRONIC INFLAMMATORY DISORDER TRIGGERED BY ALLERGIC HYPERSENSITIVITY TO FOOD AND ASSOCIATED WITH GENETIC VARIANTS IN CALPAIN 14 (CAPN14). HEREIN WE REVIEW THE GENETIC, STRUCTURAL, AND BIOCHEMICAL PROPERTIES OF CAPN14 AND ITS GENE PRODUCT CAPN14, AND ITS EMERGING ROLE IN PATIENTS WITH EOE. THE CAPN14 GENE IS LOCALIZED AT CHROMOSOME 2P23.1-P21 AND IS MOST HOMOLOGOUS TO CAPN13 (36% SEQUENCE IDENTITY), WHICH IS LOCATED 365 KB DOWNSTREAM OF CAPN14. STRUCTURALLY, CAPN14 HAS CLASSICAL CALPAIN MOTIFS, INCLUDING A CYSTEINE PROTEASE CORE. IN COMPARISON WITH OTHER HUMAN CALPAINS, CAPN14 HAS A UNIQUE EXPRESSION PATTERN, WITH THE HIGHEST LEVELS IN THE UPPER GASTROINTESTINAL TRACT, PARTICULARLY IN THE SQUAMOUS EPITHELIUM OF THE ESOPHAGUS. THE CAPN14 GENE IS POSITIONED IN AN EPIGENETIC HOTSPOT REGULATED BY IL-13, A T(H)2 CYTOKINE WITH INCREASED LEVELS IN PATIENTS WITH EOE THAT HAS BEEN SHOWN TO BE A MEDIATOR OF THE DISEASE. CAPN14 INDUCES DISRUPTIVE EFFECTS ON THE ESOPHAGEAL EPITHELIUM BY IMPAIRING EPITHELIAL BARRIER FUNCTION IN ASSOCIATION WITH LOSS OF DESMOGLEIN-1 EXPRESSION AND HAS A REGULATORY ROLE IN REPAIRING EPITHELIAL CHANGES INDUCED BY IL-13. THUS CAPN14 IS A UNIQUE PROTEASE WITH DISTINCT TISSUE-SPECIFIC EXPRESSION AND FUNCTION IN PATIENTS WITH EOE AND IS A POTENTIAL THERAPEUTIC TARGET FOR EOE AND RELATED EOSINOPHILIC AND ALLERGIC DISEASES. 2017 8 2996 14 GENETIC PROFILE AND MICROSATELLITE INSTABILITY IN A CASE OF SECONDARY ESOPHAGEAL SQUAMOUS CELL CARCINOMA 12 YEARS AFTER ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION FOR APLASTIC ANEMIA. WE REPORT ON A 16-YEAR-OLD JAPANESE BOY IN WHOM AN ESOPHAGEAL SQUAMOUS CELL CARCINOMA (ESCC) DEVELOPED 12 YEARS AFTER ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION WAS PERFORMED FOR APLASTIC ANEMIA. A HIGH FREQUENCY OF MICROSATELLITE INSTABILITY WAS DETECTED IN SAMPLES OF ESCC. MOREOVER, THE DETECTION OF PATHOGENIC VARIANTS, INCLUDING SINGLE NUCLEOTIDE SUBSTITUTION OF TP53 (C.346C>T) AND BRCA2 (C.6952C>T) AND SPLICING OF KDM6A (C.1194+2T>G), SUGGEST THAT THE DEVELOPMENT OF ESCC IN THE PATIENT WAS TRIGGERED BY IMPAIRMENT OF CHECKPOINT AND REPAIR FOR DNA DAMAGE AND EPIGENETIC MODIFICATION THROUGH ACCUMULATION OF GENE MUTATIONS INDUCED BY CHRONIC GRAFT-VERSUS-HOST DISEASE AND PROLONGED ADMINISTRATION OF TACROLIMUS. 2020 9 196 24 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 10 5181 26 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 11 3232 17 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 12 5180 20 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 13 3170 22 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 14 3671 26 INFLAMMATION AND CANCER. INFECTION AND INFLAMMATION ACCOUNT FOR APPROXIMATELY 25% OF CANCER-CAUSING FACTORS. INFLAMMATION-RELATED CANCERS ARE CHARACTERIZED BY MUTAGENIC DNA LESIONS, SUCH AS 8-OXO-7,8-DIHYDRO-2'-DEOXYGUANOSINE (8-OXODG) AND 8-NITROGUANINE. OUR PREVIOUS STUDIES DEMONSTRATED THE FORMATION OF 8-OXODG AND 8-NITROGUANINE IN THE TISSUES OF CANCER AND PRECANCEROUS LESIONS DUE TO INFECTION (E.G., OPISTHORCHIS VIVERRINI-RELATED CHOLANGIOCARCINOMA, SCHISTOSOMA HAEMATOBIUM-ASSOCIATED BLADDER CANCER, HELICOBACTER PYLORI-INFECTED GASTRIC CANCER, HUMAN PAPILLOMAVIRUS-RELATED CERVICAL CANCER, EPSTEIN-BARR VIRUS-INFECTED NASOPHARYNGEAL CARCINOMA) AND PRO-INFLAMMATORY FACTORS (E.G., ASBESTOS, NANOMATERIALS, AND INFLAMMATORY DISEASES SUCH AS BARRETT'S ESOPHAGUS AND ORAL LEUKOPLAKIA). INTERESTINGLY, SEVERAL OF OUR STUDIES SUGGESTED THAT INFLAMMATION-ASSOCIATED DNA DAMAGE IN CANCER STEM-LIKE CELLS LEADS TO CANCER DEVELOPMENT WITH AGGRESSIVE CLINICAL FEATURES. REACTIVE OXYGEN/NITROGEN SPECIES FROM INFLAMMATION DAMAGE NOT ONLY DNA BUT ALSO OTHER BIOMACROMOLECULES, SUCH AS PROTEINS AND LIPIDS, RESULTING IN THEIR DYSFUNCTION. WE IDENTIFIED OXIDATIVELY DAMAGED PROTEINS IN CANCER TISSUES BY 2D OXYBLOT FOLLOWED BY MALDI-TOF/TOF. AS AN EXAMPLE, OXIDATIVELY DAMAGED TRANSFERRIN RELEASED IRON ION, WHICH MAY MEDIATE FENTON REACTIONS AND GENERATE ADDITIONAL REACTIVE OXYGEN SPECIES. DYSFUNCTION OF ANTI-OXIDATIVE PROTEINS DUE TO THIS DAMAGE MIGHT INCREASE OXIDATIVE STRESS. SUCH DAMAGE IN BIOMACROMOLECULES MAY FORM A VICIOUS CYCLE OF OXIDATIVE STRESS, LEADING TO CANCER DEVELOPMENT. EPIGENETIC ALTERATIONS SUCH AS DNA METHYLATION AND MICRORNA DYSREGULATION PLAY VITAL ROLES IN CARCINOGENESIS, ESPECIALLY IN INFLAMMATION-RELATED CANCERS. WE EXAMINED EPIGENETIC ALTERATIONS, DNA METHYLATION AND MICRORNA DYSREGULATION, IN EPSTEIN-BARR VIRUS-RELATED NASOPHARYNGEAL CARCINOMA IN THE ENDEMIC AREA OF SOUTHERN CHINA AND FOUND SEVERAL DIFFERENTIALLY METHYLATED TUMOR SUPPRESSOR GENE CANDIDATES BY USING A NEXT-GENERATION SEQUENCER. AMONG THESE CANDIDATES, WE REVEALED HIGHER METHYLATION RATES OF RAS-LIKE ESTROGEN-REGULATED GROWTH INHIBITOR (RERG) IN BIOPSY SPECIMENS OF NASOPHARYNGEAL CARCINOMA MORE CONVENIENTLY BY USING RESTRICTION ENZYME-BASED REAL-TIME PCR. THIS RESULT MAY HELP TO IMPROVE CANCER SCREENING STRATEGIES. WE PROFILED MICRORNAS OF NASOPHARYNGEAL CARCINOMA TISSUES USING MICROARRAYS. QUANTITATIVE RT-PCR ANALYSIS CONFIRMED THE CONCORDANT DOWNREGULATION OF MIR-497 IN CANCER TISSUES AND PLASMA, SUGGESTING THAT PLASMA MIR-497 COULD BE USED AS A DIAGNOSTIC BIOMARKER FOR NASOPHARYNGEAL CARCINOMA. CHRONIC INFLAMMATION PROMOTES GENETIC AND EPIGENETIC ABERRATIONS, WITH VARIOUS PATHOGENESES. THESE CHANGES MAY BE USEFUL BIOMARKERS IN LIQUID BIOPSY FOR EARLY DETECTION AND PREVENTION OF CANCER. 2018 15 2994 28 GENETIC PATHOGENESIS OF INFLAMMATION-ASSOCIATED CANCERS IN DIGESTIVE ORGANS. EPIDEMIOLOGICAL, CLINICAL, AND BIOLOGICAL STUDIES CONVINCINGLY DEMONSTRATE THAT CHRONIC INFLAMMATION PREDISPOSES TO THE DEVELOPMENT OF HUMAN CANCERS. IN DIGESTIVE ORGANS, INFLAMMATION-ASSOCIATED CANCERS INCLUDE COLITIS-ASSOCIATED COLORECTAL CANCERS, HELICOBACTER PYLORI-ASSOCIATED GASTRIC CANCER, AS WELL AS BARRETT'S ESOPHAGUS AND ESOPHAGEAL ADENOCARCINOMA ASSOCIATED WITH CHRONIC DUODENOGASTRIC-ESOPHAGEAL REFLUX. CANCER IS A GENOMIC DISEASE, AND STEPWISE ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS OF TUMOR-RELATED GENES LEADS TO THE DEVELOPMENT OF TUMOR CELLS. RECENT GENOME ANALYSES SHOW THAT GENETIC ALTERATIONS, WHICH ARE EVOKED BY INFLAMMATION, ARE LATENTLY ACCUMULATED IN INFLAMED EPITHELIAL CELLS OF DIGESTIVE ORGANS. PRODUCTION OF REACTIVE OXYGEN AND ABERRANT EXPRESSION OF ACTIVATION-INDUCED CYTIDINE DEAMINASE, A NUCLEOTIDE-EDITING ENZYME, COULD BE INDUCED IN INFLAMED GASTROINTESTINAL EPITHELIAL CELLS AND PLAY A ROLE AS A GENOMIC MODULATOR OF INFLAMMATION-ASSOCIATED CARCINOGENESIS. UNDERSTANDING THE MOLECULAR LINKAGE BETWEEN INFLAMMATION AND GENETIC ALTERATIONS WILL OPEN UP A NEW FIELD OF TUMOR BIOLOGY AND PROVIDE A NOVEL STRATEGY FOR THE PREVENTION OF INFLAMMATION-ASSOCIATED TUMORIGENESIS. 2021 16 740 26 CANCER/TESTIS ANTIGENS: EXPRESSION, REGULATION, TUMOR INVASION, AND USE IN IMMUNOTHERAPY OF CANCERS. CANCER/TESTIS ANTIGENS (CTAS) ARE NAMED BASED ON THEIR EXPRESSION PATTERN THAT IS RESTRICTED IN A NUMBER OF NORMAL AND ABNORMAL TISSUES. TUMOR CELLS FREQUENTLY EXPRESS ANTIGENS WHOSE EXPRESSION IS TYPICALLY RESTRICTED TO GERM CELLS. THEIR UNIQUE EXPRESSION PATTERN IS GUARANTEED BY PRECISE EPIGENETIC REGULATORY MECHANISMS. BECAUSE OF THEIR TUMOR-LIMITED, HIGH IMMUNOGENICITY, AND BIASED EXPRESSION, DISCOVERY OF THESE MOLECULES PROVIDES UNPRECEDENTED OPPORTUNITIES FOR FURTHER RESEARCH AND CLINICAL DEVELOPMENT IN THE FIELD OF CANCER DIAGNOSIS AND IMMUNOTHERAPY. EVOLVING EVIDENCE REVEALS THAT A NUMBER OF CTAS STIMULATE EPITHELIAL MESENCHYMAL TRANSITION (EMT) AND GENERATION OF CANCER STEM-LIKE CELLS, INTENSIFYING METASTASIS, INVASION, AND TUMORIGENESIS. BASED ON THESE FEATURES, CTAS ATTRACT ATTENTION TO BE CONSIDERED AS IDEAL TARGETS FOR DEVELOPING SEVERAL CLINICAL TRIALS, MANY OF THEM CONCENTRATING ON CTA VACCINE THERAPY. ACCORDING TO RECENT PRACTICAL CLINICAL INTEREST, MORE CHARACTERIZATIONS OF CTA REGULATION ARE IDENTIFIED. CTA EXPRESSION HAS BEEN DEMONSTRATED IN A VARIETY OF HUMAN CANCER TISSUES, AND SOME OF THEM HAVE BEEN FOUND TO ELICIT HUMORAL AND/OR CELLULAR IMMUNE RESPONSES IN CANCER PATIENTS. CTAS ARE BRILLIANT TARGETS FOR ANTICANCER DRUG DISCOVERY, TARGETED TUMOR THERAPY, AND DIAGNOSTIC BIOMARKERS, FURTHERMORE, VALUED GENES IN THE STUDY OF IMMUNOTHERAPY, PROMOTING TUMORIGENESIS, AND MALIGNANT PROGRESSION. THIS REVIEW OUTLINES AND CATEGORIZES OUR CURRENT UNDERSTANDING OF THE COMPLEX AND BIASED PROCESS OF CTAS MRNA AND PROTEIN EXPRESSION IN CANCER, AND SUPPLIES THE MOST RECENT INFORMATION ON THEIR REGULATION AND FUNCTION. BESIDES, A CONCISE SYNOPSIS OF THE MAJOR CLINICAL TRIALS INVOLVING CTAS, AS THERAPEUTIC AVENUES, IS DISCUSSED. ABBREVIATIONS: AIRE: AUTOIMMUNE REGULATOR; CAMP: CYCLIC ADENOSINE 3',5'-CYCLIC MONOPHOSPHATE; CEA: CARCINOEMBRYONIC ANTIGEN; CML: CHRONIC MYELOID LEUKEMIA; CREB: CYCLICAMP RESPONSE ELEMENT BINDING; CSCS: CANCER STEM CELLS; CTAS: CANCER/TESTIS ANTIGENS; CTL: CYTOTOXIC T LYMPHOCYTE; DCS: DENDRITIC CELLS; EMT: EPITHELIAL-MESENCHYMAL TRANSITION; ERK: EXTRACELLULAR SIGNAL-REGULATED KINASE; ESCC: ESOPHAGEAL SQUAMOUS CELL CARCINOMA; ETS: E26 TRANSFORMATION-SPECIFIC; HIS: HISTIDINE; HLA: HUMAN LEUKOCYTE ANTIGEN; HNSCC: HEAD AND NECK SQUAMOUS CELL CARCINOMA; IFN-GAMMA: INTERFERON-GAMMA; IHC: IMMUNOHISTOCHEMISTRY; IL-7: INTERLEUKIN7; MHC: MAJOR HISTOCOMPATIBILITY COMPLEX; MMP2: MATRIX METALLOPROTEINASE 2; MTECS: MEDULLARY THYMUS EPITHELIAL CELLS; MUC1: MUCIN 1; NSCLC: NON-SMALL CELL LUNG CANCER; PRAME: PREFERENTIALLY EXPRESSED ANTIGEN IN MELANOMA; RDA: REPRESENTATIONAL DIFFERENCE ANALYSIS; SEREX: SEROLOGICAL ANALYSIS OF CDNA EXPRESSION; SSX: SYNOVIAL SARCOMA X CHROMOSOME; TAAS: TUMOR-ASSOCIATED ANTIGENS; TCR: T-CELL RECEPTOR; TCGA: THE CANCER GENOME ATLAS; TGF-BETA: TRANSFORMING GROWTH FACTOR-BETA. 2016 17 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 18 3439 27 HYPERMETHYLATION AND LOSS OF EXPRESSION OF GLUTATHIONE PEROXIDASE-3 IN BARRETT'S TUMORIGENESIS. CHRONIC GASTROESOPHAGEAL REFLUX DISEASE IS A KNOWN RISK FACTOR FOR BARRETT'S ESOPHAGUS (BE), WHICH INDUCES OXIDATIVE MUCOSAL DAMAGE. GLUTATHIONE PEROXIDASE-3 (GPX3) IS A SECRETORY PROTEIN WITH POTENT EXTRACELLULAR ANTIOXIDANT ACTIVITY. IN THIS STUDY, WE HAVE INVESTIGATED THE MRNA AND PROTEIN EXPRESSION OF GPX3, AND EXPLORED PROMOTER HYPERMETHYLATION AS AN EPIGENETIC MECHANISM FOR GPX3 GENE INACTIVATION DURING BARRETT'S CARCINOGENESIS. QUANTITATIVE REAL-TIME REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION ON 42 BARRETT'S ADENOCARCINOMAS (BAS) REVEALED CONSISTENTLY REDUCED LEVELS OF GPX3 MRNA IN 91% OF TUMOR SAMPLES. GPX3 PROMOTER HYPERMETHYLATION WAS DETECTED IN 62% OF BARRETT'S METAPLASIA, 82% OF DYSPLASIA, AND 88% OF BA SAMPLES. HYPERMETHYLATION OF BOTH ALLELES OF GPX3 WAS MOST FREQUENTLY SEEN IN BAS (P = .001). IMMUNOHISTOCHEMICAL STAINING OF GPX3 IN MATCHING TISSUE SECTIONS (NORMAL, BE, BARRETT'S DYSPLASIA, AND BA) REVEALED STRONG IMMUNOSTAINING FOR GPX3 IN NORMAL ESOPHAGEAL AND GASTRIC TISSUES. HOWEVER, WEAK TO ABSENT GPX3 STAINING WAS OBSERVED IN BARRETT'S DYSPLASIA AND ADENOCARCINOMA SAMPLES WHERE THE PROMOTER WAS HYPERMETHYLATED. THE DEGREE OF LOSS OF IMMUNOHISTOCHEMISTRY CORRELATED WITH THE HYPERMETHYLATION PATTERN (MONOALLELIC VERSUS BIALLELIC). THE OBSERVED HIGH FREQUENCY OF PROMOTER HYPERMETHYLATION AND PROGRESSIVE LOSS OF GPX3 EXPRESSION IN BA AND ITS ASSOCIATED LESIONS, TOGETHER WITH ITS KNOWN FUNCTION AS A POTENT ANTIOXIDANT, SUGGEST THAT EPIGENETIC INACTIVATION AND REGULATION OF GLUTATHIONE PATHWAY MAY BE CRITICAL IN THE DEVELOPMENT AND PROGRESSION OF BE. 2005 19 4438 28 MOLECULAR FINDINGS IN BARRETT'S EPITHELIUM. BARRETT'S METAPLASIA IS A PREMALIGNANT CONDITION AND REMAINS THE NUMBER ONE RISK FACTOR FOR DEVELOPING ADENOCARCINOMA. THE HISTOLOGIC CHANGES LEADING TO ADENOCARCINOMA ARE ACCOMPANIED BY GENETIC DISTURBANCES OF THE EPITHELIAL CELLS ITSELF AS WELL AS THE SURROUNDING STROMA. GENETIC AND EPIGENETIC EVENTS AFFECT THE CELL CYCLE, LEADING TO GROWTH SELF-SUFFICIENCY AND IGNORATION OF ANTIGROWTH SIGNALS. THE BALANCE OF CELL TURNOVER IS INSTABLE BY AVOIDANCE OF APOPTOSIS AND A GENERAL LIMITLESS OF THE REPLICATIVE POTENTIAL OF THE (MUTATED) STEM CELLS. SUSTAINED ANGIOGENESIS, NOT ONLY A CONSEQUENCE OF CHRONIC INFLAMMATION, MAY PRECEDE INVASION OF GENETICALLY INSTABLE (ANEUPLOID) CELLS. THE PRINCIPAL GENETIC CHANGES IN BARRETT'S CARCINOGENESIS ARE COMPARABLE TO THOSE KNOWN FROM OTHER EPITHELIAL MALIGNANCIES. LOSS OF P16 GENE EXPRESSION (BY DELETION OR HYPERMETHYLATION), THE LOSS OF P53 EXPRESSION (BY MUTATION AND DELETION), THE INCREASE IN CYCLIN EXPRESSION, AND THE LOSSES OF RB, APC AS WELL AS VARIOUS CHROMOSOMAL LOCI HAVE BEEN REPORTED. SINCE THESE GENETIC OR EPIGENETIC ALTERATIONS ARE NEITHER TUMOR NOR STAGE SPECIFIC, THEY COULD NOT GAIN DIAGNOSTIC SIGNIFICANCE AS BIOMARKERS UNTIL NOW. 2004 20 4960 16 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