1  3232 66 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
2  3413 21 HSA-MIR-29C AND HSA-MIR-135B DIFFERENTIAL EXPRESSION AS POTENTIAL BIOMARKER OF GASTRIC CARCINOGENESIS. AIM: TO INVESTIGATE THE EXPRESSION PROFILES OF HSA-MIR-29C AND HSA-MIR-135B IN GASTRIC MUCOSAL SAMPLES AND THEIR VALUES AS GASTRIC CARCINOGENESIS BIOMARKERS. METHODS: THE EXPRESSION LEVELS OF HSA-MIR-29C AND HSA-MIR-135B IN NORMAL GASTRIC MUCOSA, NON-ATROPHIC CHRONIC GASTRITIS, INTESTINAL METAPLASIA AND INTESTINAL-TYPE GASTRIC ADENOCARCINOMA WERE ANALYSED USING QUANTITATIVE REAL-TIME PCR. THE DIFFERENCE BETWEEN HSA-MIR-29C AND HSA-MIR-135B EXPRESSION PROFILES IN THE GROUPED SAMPLES WAS EVALUATED BY ANOVA AND STUDENT'S T-TEST TESTS. THE RESULTS WERE ADJUSTED FOR MULTIPLE TESTING BY USING BONFERRONI'S CORRECTION. P VALUES </= 0.05 WERE CONSIDERED STATISTICALLY SIGNIFICANT. TO EVALUATE HSA-MIR-29C AND HSA-MIR-135B EXPRESSIONS AS POTENTIAL BIOMARKERS OF GASTRIC CARCINOGENESIS, WE PERFORMED A RECEIVER OPERATING CHARACTERISTIC CURVE ANALYSIS AND THE DERIVED AREA UNDER THE CURVE, AND A CATEGORICAL PRINCIPAL COMPONENTS ANALYSIS. IN SILICO IDENTIFICATION OF THE GENETIC TARGETS OF HSA-MIR-29C AND HSA-MIR-135B WAS PERFORMED USING DIFFERENT PREDICTION TOOLS, IN ORDER TO IDENTIFY POSSIBLE GENES INVOLVED IN GASTRIC CARCINOGENESIS. RESULTS: THE EXPRESSION LEVELS OF HSA-MIR-29C WERE HIGHER IN NORMAL GASTRIC MUCOSAL SAMPLES, AND DECREASED PROGRESSIVELY IN NON-ATROPHIC CHRONIC GASTRITIS SAMPLES, INTESTINAL METAPLASIA SAMPLES AND INTESTINAL-TYPE GASTRIC ADENOCARCINOMA SAMPLES. THE EXPRESSION OF HSA-MIR-29C IN THE GASTRIC LESIONS SHOWED THAT NON-ATROPHIC GASTRITIS HAVE AN INTERMEDIATE PROFILE TO GASTRIC NORMAL MUCOSA AND INTESTINAL-TYPE GASTRIC ADENOCARCINOMA, AND THAT INTESTINAL METAPLASIA SAMPLES PRESENTED AN EXPRESSION PATTERN SIMILAR TO THAT IN INTESTINAL-TYPE GASTRIC ADENOCARCINOMA. THIS MICRORNA (MIRNA) HAS A GOOD DISCRIMINATORY ACCURACY BETWEEN NORMAL GASTRIC SAMPLES AND (1) INTESTINAL-TYPE GASTRIC ADENOCARCINOMA; AND (2) INTESTINAL METAPLASIA, AND REGULATES THE DMNT3A ONCOGENE. HSA-MIR-135B IS UP-REGULATED IN NON-ATROPHIC CHRONIC GASTRITIS AND INTESTINAL METAPLASIA SAMPLES AND DOWN-REGULATED IN NORMAL GASTRIC MUCOSA AND INTESTINAL-TYPE GASTRIC ADENOCARCINOMA SAMPLES. NON-ATROPHIC CHRONIC GASTRITIS AND INTESTINAL METAPLASIA ARE SIGNIFICANTLY DIFFERENT FROM NORMAL GASTRIC MUCOSA SAMPLES. HSA-MIR-135B EXPRESSION PRESENTED A GREATER DISCRIMINATORY ACCURACY BETWEEN NORMAL SAMPLES AND GASTRIC LESIONS. THIS MIRNA WAS ASSOCIATED WITH HELICOBACTER PYLORI PRESENCE IN NON-ATROPHIC CHRONIC GASTRITIS SAMPLES AND REGULATES THE APC AND KLF4 TUMOUR SUPPRESSOR GENES. CONCLUSION: OUR RESULTS PROVIDE EVIDENCE OF EPIGENETIC ALTERATIONS IN NON-ATROPHIC CHRONIC GASTRITIS AND INTESTINAL METAPLASIA AND SUGGEST THAT HSA-MIR-29C AND HSA-MIR-135B ARE PROMISING BIOMARKERS OF GASTRIC CARCINOGENESIS.	2016	
                                                                                                                                                                             
3  3227 27 HELICOBACTER PYLORI INFECTION-INDUCED H3SER10 PHOSPHORYLATION IN STEPWISE GASTRIC CARCINOGENESIS AND ITS CLINICAL IMPLICATIONS. BACKGROUND: OUR PREVIOUS WORKS HAVE DEMONSTRATED THAT HELICOBACTER PYLORI (HP) INFECTION CAN ALTER HISTONE H3 SERINE 10 PHOSPHORYLATION STATUS IN GASTRIC EPITHELIAL CELLS. HOWEVER, WHETHER HELICOBACTER PYLORI-INDUCED HISTONE H3 SERINE 10 PHOSPHORYLATION PARTICIPATES IN GASTRIC CARCINOGENESIS IS UNKNOWN. WE INVESTIGATE THE EXPRESSION OF HISTONE H3 SERINE 10 PHOSPHORYLATION IN VARIOUS STAGES OF GASTRIC DISEASE AND EXPLORE ITS CLINICAL IMPLICATION. MATERIALS AND METHODS: STOMACH BIOPSY SAMPLES FROM 129 PATIENTS WERE COLLECTED AND STAINED WITH HISTONE H3 SERINE 10 PHOSPHORYLATION, KI67, AND HELICOBACTER PYLORI BY IMMUNOHISTOCHEMISTRY STAINING, EXPRESSED AS LABELING INDEX. THEY WERE CATEGORIZED INTO NONATROPHIC GASTRITIS, CHRONIC ATROPHIC GASTRITIS, INTESTINAL METAPLASIA, LOW-GRADE INTRAEPITHELIAL NEOPLASIA, HIGH-GRADE INTRAEPITHELIAL NEOPLASIA, AND INTESTINAL-TYPE GASTRIC CANCER GROUPS. HELICOBACTER PYLORI INFECTION WAS DETERMINED BY EITHER (13) C-UREA BREATH TEST OR IMMUNOHISTOCHEMISTRY STAINING. RESULTS: IN HELICOBACTER PYLORI-NEGATIVE PATIENTS, LABELING INDEX OF HISTONE H3 SERINE 10 PHOSPHORYLATION WAS GRADUALLY INCREASED IN NONATROPHIC GASTRITIS, CHRONIC ATROPHIC GASTRITIS, INTESTINAL METAPLASIA GROUPS, PEAKED AT LOW-GRADE INTRAEPITHELIAL NEOPLASIA, AND DECLINED IN HIGH-GRADE INTRAEPITHELIAL NEOPLASIA AND GASTRIC CANCER GROUPS. IN HELICOBACTER PYLORI-INFECTED PATIENTS, LABELING INDEX OF HISTONE H3 SERINE 10 PHOSPHORYLATION FOLLOWED THE SIMILAR PATTERN AS ABOVE, WITH INCREASED EXPRESSION OVER THE CORRESPONDING HELICOBACTER PYLORI-NEGATIVE CONTROLS EXCEPT IN NONATROPHIC GASTRITIS PATIENT WHOSE LABELING INDEX WAS DECREASED WHEN COMPARED WITH HELICOBACTER PYLORI-NEGATIVE CONTROL. LABELING INDEX OF KI67 IN HELICOBACTER PYLORI-NEGATIVE GROUPS WAS HIGHER IN GASTRIC CANCER THAN CHRONIC ATROPHIC GASTRITIS AND LOW-GRADE INTRAEPITHELIAL NEOPLASIA GROUPS, AND HIGHER IN INTESTINAL METAPLASIA GROUP COMPARED WITH CHRONIC ATROPHIC GASTRITIS GROUP. IN HELICOBACTER PYLORI-POSITIVE GROUPS, KI67 LABELING INDEX WAS INCREASED STEPWISE FROM NONATROPHIC GASTRITIS TO GASTRIC CANCER EXCEPT SLIGHTLY DECREASE IN CHRONIC ATROPHIC GASTRITIS GROUP. IN ADDITION, WE NOTED THAT HISTONE H3 SERINE 10 PHOSPHORYLATION STAINING IS ACCOMPANIED WITH ITS LOCATION CHANGES FROM GASTRIC GLAND BOTTOM EXPANDED TO WHOLE GLAND AS DISEASE STAGE PROGRESS. CONCLUSIONS: THESE RESULTS INDICATE THAT STEPWISE GASTRIC CARCINOGENESIS IS ASSOCIATED WITH ALTERED HISTONE H3 SERINE 10 PHOSPHORYLATION, HELICOBACTER PYLORI INFECTION ENHANCES HISTONE H3 SERINE 10 PHOSPHORYLATION EXPRESSION IN THESE PROCESSES; IT IS ALSO ACCOMPANIED WITH HISTONE H3 SERINE 10 PHOSPHORYLATION LOCATION CHANGE FROM GLAND BOTTOM STAINING EXPAND TO WHOLE GLAND EXPRESSION. THE RESULTS SUGGEST THAT EPIGENETIC DYSREGULATION MAY PLAY IMPORTANT ROLES IN HELICOBACTER PYLORI-INDUCED GASTRIC CANCER.	2018	

4  3231 19 HELICOBACTER PYLORI-INDUCED MODULATION OF THE PROMOTER METHYLATION OF WNT ANTAGONIST GENES IN GASTRIC CARCINOGENESIS. BACKGROUND: THIS STUDY AIMED TO INVESTIGATE THE CHANGES IN THE PROMOTER METHYLATION AND GENE EXPRESSION OF MULTIPLE WNT ANTAGONISTS BETWEEN THE CHRONIC INFECTION AND ERADICATION OF HELICOBACTER PYLORI (H. PYLORI) IN GASTRIC CARCINOGENESIS. METHODS: THE LEVELS OF METHYLATION AND CORRESPONDING MRNA EXPRESSION OF SEVEN WNT ANTAGONIST GENES (SFRP1, -2, -5, DKK1, -2, -3, WIF1) WERE COMPARED AMONG THE PATIENTS WITH H. PYLORI-POSITIVE GASTRIC CANCERS (GCS), AND H. PYLORI-POSITIVE AND H. PYLORI-NEGATIVE CONTROLS, BY QUANTITATIVE METHYLIGHT ASSAY AND REAL-TIME REVERSE TRANSCRIPTION (RT)-POLYMERASE CHAIN REACTION (PCR), RESPECTIVELY. THE CHANGES OF THE METHYLATION AND EXPRESSION LEVELS OF THE GENES WERE ALSO COMPARED BETWEEN THE H. PYLORI ERADICATION AND H. PYLORI-PERSISTENT GROUPS 1 YEAR AFTER ENDOSCOPIC RESECTION OF GCS. RESULTS: THE METHYLATION LEVELS OF SFRP AND DKK FAMILY GENES WERE SIGNIFICANTLY INCREASED IN THE PATIENTS WITH H. PYLORI-POSITIVE GCS AND FOLLOWED BY H. PYLORI-POSITIVE CONTROLS COMPARED WITH H. PYLORI-NEGATIVE CONTROLS (P < 0.001). SFRP1, -2, AND DKK3 GENE EXPRESSION WAS STEPWISE DOWNREGULATED FROM H. PYLORI-NEGATIVE CONTROLS, H. PYLORI-POSITIVE CONTROLS, AND TO H. PYLORI-POSITIVE GCS (P < 0.05). AMONG THE WNT ANTAGONISTS, ONLY THE DEGREES OF METHYLATION AND DOWNREGULATION OF DKK3 WERE SIGNIFICANTLY REDUCED AFTER H. PYLORI ERADICATION (P < 0.05). CONCLUSION: EPIGENETIC SILENCING OF SFRP AND DKK FAMILY GENES MAY FACILITATE THE FORMATION OF AN EPIGENETIC FIELD DURING H. PYLORI-ASSOCIATED GASTRIC CARCINOGENESIS. THE EPIGENETIC FIELD MAY NOT BE REVERSED EVEN AFTER H. PYLORI ERADICATION EXCEPT BY DKK3 METHYLATION.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
5  4725 24 NORMAL GASTRIC TISSUE HELICOBACTER PYLORI INFECTION IS ASSOCIATED WITH EPIGENETIC AGE ACCELERATION, INCREASED MITOTIC TICK RATE, TISSUE CELL COMPOSITION, AND NATURAL KILLER CELL METHYLATION ALTERATIONS. BACKGROUND: GASTRIC ADENOCARCINOMAS ARE A LEADING CAUSE OF GLOBAL MORTALITY, ASSOCIATED WITH CHRONIC INFECTION WITH HELICOBACTER PYLORI . THE MECHANISMS BY WHICH INFECTION WITH H. PYLORI CONTRIBUTES TO CARCINOGENESIS ARE NOT WELL UNDERSTOOD. RECENT STUDIES FROM SUBJECTS WITH AND WITHOUT GASTRIC CANCER HAVE IDENTIFIED SIGNIFICANT DNA METHYLATION ALTERATIONS IN NORMAL GASTRIC MUCOSA ASSOCIATED WITH H. PYLORI INFECTION AND GASTRIC CANCER RISK. HERE WE FURTHER INVESTIGATED DNA METHYLATION ALTERATIONS IN NORMAL GASTRIC MUCOSA IN GASTRIC CANCER CASES (N = 42) AND CONTROL SUBJECTS (N = 42) WITH H. PYLORI INFECTION DATA. WE ASSESSED TISSUE CELL TYPE COMPOSITION, DNA METHYLATION ALTERATIONS WITHIN CELL POPULATIONS, EPIGENETIC AGING, AND REPETITIVE ELEMENT METHYLATION. RESULTS: IN NORMAL GASTRIC MUCOSA OF BOTH GASTRIC CANCER CASES AND CONTROL SUBJECTS, WE OBSERVED INCREASED EPIGENETIC AGE ACCELERATION ASSOCIATED WITH H. PYLORI INFECTION. WE ALSO OBSERVED AN INCREASED MITOTIC TICK RATE ASSOCIATED WITH H. PYLORI INFECTION IN BOTH GASTRIC CANCER CASES AND CONTROLS. SIGNIFICANT DIFFERENCES IN IMMUNE CELL POPULATIONS ASSOCIATED WITH H. PYLORI INFECTION IN NORMAL TISSUE FROM CANCER CASES AND CONTROLS WERE IDENTIFIED USING DNA METHYLATION CELL TYPE DECONVOLUTION. WE ALSO FOUND NATURAL KILLER CELL-SPECIFIC METHYLATION ALTERATIONS IN NORMAL MUCOSA FROM GASTRIC CANCER PATIENTS WITH H. PYLORI INFECTION. CONCLUSIONS: OUR FINDINGS FROM NORMAL GASTRIC MUCOSA PROVIDE INSIGHT INTO UNDERLYING CELLULAR COMPOSITION AND EPIGENETIC ASPECTS OF H. PYLORI ASSOCIATED GASTRIC CANCER ETIOLOGY.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
6   672 21 BRAF, KRAS AND HELICOBACTER PYLORI EPIGENETIC CHANGES-ASSOCIATED CHRONIC GASTRITIS IN EGYPTIAN PATIENTS WITH AND WITHOUT GASTRIC CANCER. WE AIMED TO STUDY MLH1 AND MGMT METHYLATION STATUS IN HELICOBACTER PYLORI-ASSOCIATED CHRONIC GASTRITIS IN EGYPTIAN PATIENTS WITH AND WITHOUT GASTRIC CANCER. 39 PATIENTS WERE INCLUDED IN OUR STUDY. THEY WERE DIVIDED INTO 2 GROUPS; PATIENTS WITHOUT (GROUP I) AND WITH GASTRIC ADENOCARCINOMA (GROUP II). PATIENTS WERE SUBJECTED TO CLINICAL EXAMINATION, ABDOMINAL ULTRASOUND AND UPPER ENDOSCOPY FOR GASTRIC BIOPSY. BIOPSIES WERE SUBJECTED TO UREASE TEST, HISTOLOGICAL EXAMINATION, AND DNA PURIFICATION. H. PYLORI, BRAF, KRAS, MLH1 AND MGMT METHYLATION WERE ASSESSED BY QUANTITATIVE PCR. DNA SEQUENCING WAS PERFORMED TO ASSESS BRAF AND KRAS GENES MUTATION. QPCR OF H. PYLORI WAS SIGNIFICANTLY HIGHER IN PATIENTS WITH ADENOCARCINOMA (GROUP II) THAN THOSE WITHOUT ADENOCARCINOMA (GROUP I); WITH A P < 0.001 AS WELL AS IN PATIENTS WITH AGE ABOVE 50 YEARS WITH A P VALUE = 0.008. BY APPLYING LOGISTIC REGRESSION ANALYSIS IT WAS REPORTED THAT THE H. PYLORI QPCR IS A SIGNIFICANT PREDICTOR TO THE ADENOCARCINOMA WITH OR = 1.025 (95 % CI: 1. 002-1.048), WITH SENSITIVITY OF 90 % AND SPECIFICITY OF 100 %. ADENOCARCINOMA PATIENTS HAD A SIGNIFICANTLY HIGHER MEAN AGE AND LEVELS OF H. PYLORI, BRAF, K-RAS, METHYLATED MGMT AND METHYLATED MLH1 THAN THOSE OF GASTRITIS PATIENTS. DNA SEQUENCE ANALYSIS OF BRAF (CODON 12) AND KRAS (CODON 600) HAD GENES MUTATION IN GASTRIC ADENOCARCINOMA VERSUS CHRONIC GASTRITIS. CONCLUSION: H. PYLORI MAY CAUSE EPIGENETIC CHANGES PREDISPOSING THE PATIENTS TO CANCER STOMACH. ESTIMATION OF H. PYLORI BY QPCR CAN BE A GOOD PREDICTOR TO ADENOCARCINOMA. BRAF AND KRAS GENES MUTATION WERE REVELED IN GASTRITIS AND ADENOCARCINOMA PATIENTS.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
7  3134 25 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
8  3229 30 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
9  2430 23 EPIGENETIC SILENCING OF MIR-210 INCREASES THE PROLIFERATION OF GASTRIC EPITHELIUM DURING CHRONIC HELICOBACTER PYLORI INFECTION. PERSISTENT COLONIZATION OF THE GASTRIC MUCOSA BY HELICOBACTER PYLORI (HP) ELICITS CHRONIC INFLAMMATION AND ABERRANT EPITHELIAL CELL PROLIFERATION, WHICH INCREASES THE RISK OF GASTRIC CANCER. HERE WE EXAMINE THE ABILITY OF MICRORNAS TO MODULATE GASTRIC CELL PROLIFERATION IN RESPONSE TO PERSISTENT HP INFECTION AND FIND THAT EPIGENETIC SILENCING OF MIR-210 PLAYS A KEY ROLE IN GASTRIC DISEASE PROGRESSION. IMPORTANTLY, DNA METHYLATION OF THE MIR-210 GENE IS INCREASED IN HP-POSITIVE HUMAN GASTRIC BIOPSIES AS COMPARED WITH HP-NEGATIVE CONTROLS. MOREOVER, SILENCING OF MIR-210 IN GASTRIC EPITHELIAL CELLS PROMOTES PROLIFERATION. WE IDENTIFY STMN1 AND DIMT1 AS MIR-210 TARGET GENES AND DEMONSTRATE THAT INHIBITION OF MIR-210 EXPRESSION AUGMENTS CELL PROLIFERATION BY ACTIVATING STMN1 AND DIMT1. TOGETHER, OUR RESULTS HIGHLIGHT INFLAMMATION-INDUCED EPIGENETIC SILENCING OF MIR-210 AS A MECHANISM OF INDUCTION OF CHRONIC GASTRIC DISEASES, INCLUDING CANCER, DURING HP INFECTION.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
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  2439 24 EPIGENETIC SILENCING OF THE MLH1 PROMOTER IN RELATION TO THE DEVELOPMENT OF GASTRIC CANCER AND ITS USE AS A BIOMARKER FOR PATIENTS WITH MICROSATELLITE INSTABILITY: A SYSTEMATIC ANALYSIS. BACKGROUND/AIMS: HUMAN MUTL HOMOLOG 1 (MLH1) PROMOTER METHYLATION WAS REPORTED IN GASTRIC CANCER (GC). THIS STUDY DETERMINED THE CLINICOPATHOLOGICAL, PROGNOSTIC, AND DIAGNOSTIC EFFECTS OF MLH1 PROMOTER METHYLATION IN GC. METHODS: THE COMBINED ODDS RATIO (OR) OR HAZARD RATIO (HR) AND THEIR CORRESPONDING 95% CONFIDENCE INTERVALS (95% CI) WERE CALCULATED. THE POOLED SENSITIVITY, SPECIFICITY, AND AREA UNDER THE CURVE (AUC) WERE ANALYZED. RESULTS: A TOTAL OF 4654 GC PATIENTS AND 3669 NON-MALIGNANT CONTROLS WERE IDENTIFIED IN THIS SYSTEMATIC ANALYSIS. MLH1 PROMOTER METHYLATION WAS SIGNIFICANTLY HIGHER IN GC SAMPLES THAN IN GASTRIC ADENOMAS, CHRONIC GASTRITIS, ADJACENT TISSUES, NORMAL GASTRIC MUCOSA, AND NORMAL HEALTHY BLOOD SAMPLES, BUT IT EXHIBITED A SIMILAR FREQUENCY IN GC VS. INTESTINAL METAPLASIA AND DYSPLASIA SAMPLES. MLH1 PROMOTER METHYLATION CORRELATED WITH AGE AND MICROSATELLITE INSTABILITY (MSI), BUT IT WAS NOT ASSOCIATED WITH GENDER, H. PYLORI INFECTION, SMOKING, DRINKING BEHAVIORS, PATHOLOGICAL HISTOLOGY, TUMOR DIFFERENTIATION, CLINICAL STAGE, LYMPH NODE STATUS, DISTANT METASTASIS, OR OVERALL SURVIVAL OF GC. MLH1 PROMOTER METHYLATION EXHIBITED A POOR SENSITIVITY VALUE (< 0.5) IN PATIENTS WITH GC COMPARED WITH ADJACENT TISSUES, GASTRIC ADENOMAS, CHRONIC GASTRITIS, NORMAL GASTRIC MUCOSA, AND NORMAL HEALTHY BLOOD SAMPLES. THE POOLED SENSITIVITY, SPECIFICITY, AND AUC OF MLH1 PROMOTER METHYLATION IN GC WITH MSI VS. GC WITH MICROSATELLITE STABILITY (MSS) SAMPLES WERE 0.64, 0.96, AND 0.90, RESPECTIVELY. CONCLUSIONS: OUR RESULTS SUGGEST THAT THE DETECTION OF MLH1 PROMOTER METHYLATION MAY BE A POTENTIAL PROGNOSTIC BIOMARKER FOR GC PATIENTS WITH MSI.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
12  3298 27 HIGH-DEFINITION CPG METHYLATION OF NOVEL GENES IN GASTRIC CARCINOGENESIS IDENTIFIED BY NEXT-GENERATION SEQUENCING. GASTRIC CANCERS ARE THE MOST FREQUENT GASTRIC MALIGNANCY AND USUALLY ARISE IN THE SEQUENCE OF HELICOBACTER PYLORI-ASSOCIATED CHRONIC GASTRITIS. CPG METHYLATION IS A CENTRAL MECHANISM OF EPIGENETIC GENE REGULATION AFFECTING CANCER-RELATED GENES, AND OCCURS EARLY IN GASTRIC CARCINOGENESIS. DNA SAMPLES FROM NON-METAPLASTIC GASTRIC MUCOSA WITH VARIABLE LEVELS OF GASTRITIS (NON-METAPLASTIC MUCOSA), INTESTINAL METAPLASIA, OR GASTRIC CANCER WERE SCREENED WITH METHYLATION ARRAYS FOR CPG METHYLATION OF CANCER-RELATED GENES AND 30 GENE TARGETS WERE FURTHER CHARACTERIZED BY HIGH-DEFINITION BISULFITE NEXT-GENERATION SEQUENCING. IN ADDITION, DATA FROM THE CANCER GENOME ATLAS WERE ANALYZED FOR CORRELATION OF METHYLATION WITH GENE EXPRESSION. OVERALL, 13 GENES HAD SIGNIFICANTLY INCREASED CPG METHYLATION IN GASTRIC CANCER VS NON-METAPLASTIC MUCOSA (BRINP1, CDH11, CHFR, EPHA5, EPHA7, FGF2, FLI1, GALR1, HS3ST2, PDGFRA, SEZ6L, SGCE, AND SNRPN). FURTHER, MOST OF THESE GENES HAD CORRESPONDING REDUCED EXPRESSION LEVELS IN GASTRIC CANCER COMPARED WITH INTESTINAL METAPLASIA, INCLUDING NOVEL HYPERMETHYLATED GENES IN GASTRIC CANCER (FLI1, GALR1, SGCE, AND SNRPN), SUGGESTING THAT THEY MAY REGULATE NEOPLASTIC TRANSFORMATION FROM NON-MALIGNANT INTESTINAL METAPLASIA TO CANCER. OUR DATA SUGGEST A TUMOR-SUPPRESSOR ROLE FOR FLI1 IN GASTRIC CANCER, CONSISTENT WITH RECENTLY REPORTED DATA IN BREAST CANCER. FOR THE GENES WITH STRONGEST METHYLATION/EXPRESSION CORRELATION, NAMELY FLI1, THE EXPRESSION WAS LOWEST IN MICROSATELLITE-UNSTABLE TUMORS COMPARED WITH OTHER GASTRIC CANCER MOLECULAR SUBTYPES. IMPORTANTLY, REDUCED EXPRESSION OF HYPERMETHYLATED BRINP1 AND SGCE WAS SIGNIFICANTLY ASSOCIATED WITH FAVORABLE SURVIVAL IN GASTRIC CANCER. IN SUMMARY, WE REPORT NOVEL METHYLATION GENE TARGETS THAT MAY HAVE FUNCTIONAL ROLES IN DISCRETE STAGES OF GASTRIC CARCINOGENESIS AND MAY SERVE AS BIOMARKERS FOR DIAGNOSIS AND PROGNOSIS OF GASTRIC CANCER.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
13   600 18 BETA-DEFENSINS AND ANALOGS IN HELICOBACTER PYLORI INFECTIONS: MRNA EXPRESSION LEVELS, DNA METHYLATION, AND ANTIBACTERIAL ACTIVITY. ANTIMICROBIAL PEPTIDES CAN PROTECT THE GASTRIC MUCOSA FROM BACTERIA, BUT HELICOBACTER PYLORI (H. PYLORI) CAN EQUALLY COLONIZE THE GASTRIC APPARATUS. TO UNDERSTAND BETA-DEFENSIN FUNCTION IN H. PYLORI-ASSOCIATED CHRONIC GASTRITIS, WE INVESTIGATED SUSCEPTIBILITY, HUMAN BETA-DEFENSIN MRNA EXPRESSION, AND DNA METHYLATION CHANGES TO PROMOTERS IN THE GASTRIC MUCOSA WITH OR WITHOUT H. PYLORI INFECTION. WE STUDIED THE EXPRESSION OF HBD2 (GENE NAME DEFB4A), HBD3 (DEFB103A), AND HBD4 (DEFB104) USING REAL-TIME PCR IN 15 CONTROL AND 10 H. PYLORI INFECTION PATIENT GASTRIC SPECIMENS. THIS STUDY DEMONSTRATES THAT H. PYLORI INFECTION IS RELATED TO GASTRIC ENHANCEMENT OF INDUCIBLE HBD2, BUT INDUCIBLE HBD3 AND HBD4 EXPRESSION LEVELS REMAINED UNCHANGED. HBD2 GENE METHYLATION LEVELS WERE OVERALL HIGHER IN H. PYLORI-NEGATIVE SAMPLES THAN IN H. PYLORI-POSITIVE SAMPLES. WE ALSO ASSESSED ANTIMICROBIAL SUSCEPTIBILITY USING GROWTH ON BLOOD AGAR. THE H. PYLORI STRAIN TOX+ WAS SUSCEPTIBLE TO ALL DEFENSINS TESTED AND THEIR ANALOGS (3N, 3NI). THESE RESULTS SHOW THAT HBD2 IS INVOLVED IN GASTRITIS DEVELOPMENT DRIVEN BY H. PYLORI, WHICH FACILITATES THE CREATION OF AN EPIGENETIC FIELD DURING H. PYLORI-ASSOCIATED GASTRIC TUMORIGENESIS.	2019	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
14  3805 35 INTESTINE-SPECIFIC HOMEOBOX (ISX) INDUCES INTESTINAL METAPLASIA AND CELL PROLIFERATION TO CONTRIBUTE TO GASTRIC CARCINOGENESIS. BACKGROUND: HELICOBACTER PYLORI INDUCES CHRONIC INFLAMMATION AND INTESTINAL METAPLASIA (IM) THROUGH GENETIC AND EPIGENETIC CHANGES AND ACTIVATION OF INTRACELLULAR SIGNALING PATHWAYS THAT CONTRIBUTE TO GASTRIC CARCINOGENESIS. HOWEVER, THE PRECISE MECHANISM OF IM IN GASTRIC CARCINOGENESIS HAS NOT BEEN FULLY ELUCIDATED. WE PREVIOUSLY FOUND THAT INTESTINE-SPECIFIC HOMEOBOX (ISX) MRNA EXPRESSION INCREASED IN ORGANOIDS CULTURED FROM HELICOBACTER-INFECTED MOUSE MUCOSA. IN THIS STUDY, WE ELUCIDATE THE ROLE OF ISX IN THE DEVELOPMENT OF IM AND GASTRIC CARCINOGENESIS. METHODS: ISX EXPRESSION WAS ASSESSED IN HELICOBACTER-INFECTED MOUSE AND HUMAN GASTRIC MUCOSA. MKN45 GASTRIC CANCER CELLS WERE CO-CULTURED WITH H. PYLORI TO DETERMINE WHETHER HELICOBACTER INFECTION INDUCED ISX EXPRESSION. WE ESTABLISHED STABLE MKN45 TRANSFECTED CELLS EXPRESSING ISX (STABLE-ISX MKN45) AND PERFORMED A SPHEROID COLONY FORMATION ASSAY AND A XENOGRAFT MODEL. WE PERFORMED ISX IMMUNOHISTOCHEMISTRY IN CANCER AND ADJACENT GASTRIC TISSUES. RESULTS: ISX EXPRESSION WAS INCREASED IN MOUSE AND HUMAN GASTRIC MUCOSA INFECTED WITH HELICOBACTER. THE PRESENCE OF IM AND H. PYLORI INFECTION IN HUMAN STOMACH WAS CORRELATED WITH ISX EXPRESSION. H. PYLORI INDUCED ISX MRNA AND PROTEIN EXPRESSION. CDX1/2, CYCLIND1, AND MUC2 WERE UPREGULATED IN STABLE-ISX MKN45, WHEREAS MUC5AC WAS DOWNREGULATED. STABLE-ISX MKN45 CELLS FORMED MORE SPHEROID COLONIES, AND HAD HIGH TUMORIGENIC ABILITY. ISX EXPRESSION IN GASTRIC CANCER AND ADJACENT MUCOSA WERE CORRELATED. CONCLUSIONS: ISX EXPRESSION INDUCED BY H. PYLORI INFECTION MAY LEAD TO IM AND HYPERPROLIFERATION OF GASTRIC MUCOSA THROUGH CDX1/2 AND CYCLIND1 EXPRESSION, CONTRIBUTING TO GASTRIC CARCINOGENESIS.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
15  4232 22 METHYLATION OF RUNX3 IN VARIOUS TYPES OF HUMAN CANCERS AND PREMALIGNANT STAGES OF GASTRIC CARCINOMA. ACCUMULATING EVIDENCE HAS IDENTIFIED A MECHANISM POTENTIALLY RESPONSIBLE FOR THE INACTIVATION OF TUMOR SUPPRESSOR GENES, NAMELY TRANSCRIPTIONAL SILENCING BY ABERRANT METHYLATION OF CPG ISLANDS. A PREVIOUS STUDY HAS SHOWN THE LOSS OF RUNX3 EXPRESSION, DUE TO ABERRANT METHYLATION OF ITS CPG ISLAND, IN GASTRIC CANCER CELL LINES, SUGGESTING THAT RUNX3 IS A TARGET FOR EPIGENETIC GENE SILENCING IN GASTRIC CARCINOGENESIS. HOWEVER, THERE ARE LIMITED DATA ON THE METHYLATION STATUS OF RUNX3 IN THE NEOPLASTIC AND NON-NEOPLASTIC TISSUES IN VARIOUS TYPES OF HUMAN CANCERS, INCLUDING GASTRIC CANCER. HERE, WE REPORT THAT 60% OF GASTRIC CANCER CELL LINES AND 64% OF PRIMARY GASTRIC CARCINOMAS (N=75) WERE METHYLATED AT THE RUNX3 CPG ISLAND. RUNX3 METHYLATION WAS ALSO DETECTED IN HEPATOCELLULAR CARCINOMAS (73%, N=48), LARYNX CANCERS (62%, N=37), LUNG CANCERS (46%, N=24), BREAST CANCERS (25%, N=25), PROSTATE CANCERS (23%, N=44), ENDOMETRIAL CANCERS (12.5%, N=24), COLON CANCERS (4.9%, N=61) AND UTERINE CERVICAL CANCERS (2.5%, N=40), SHOWING THAT RUNX3 METHYLATION IS NOT RESTRICTED TO GASTRIC CANCER. INTERESTINGLY, THE RUNX3 METHYLATION WAS ESPECIALLY FREQUENT IN TUMORS FROM TISSUES OF A FOREGUT DERIVATIVE, THAT IS, THE STOMACH, LIVER, LARYNX AND LUNG. NEXT, THE METHYLATION STATUS OF RUNX3 IN VARIOUS NON-NEOPLASTIC TISSUES WAS EXAMINED, INCLUDING THE PREMALIGNANT LESIONS OF GASTRIC CARCINOMAS. THE RUNX3 METHYLATION WAS FOUND IN 8.1% OF CHRONIC GASTRITIS (N=99), 28.1% OF INTESTINAL METAPLASIA (N=32), 27.3% OF GASTRIC ADENOMAS (N=77) AND 64% OF GASTRIC CARCINOMAS (N=75), BUT NOT IN CHRONIC HEPATITIS B, NORMAL PROSTATE AND COLON MUCOSA, EVEN THOUGH IN CASES OF CHRONIC HEPATITIS, THE METHYLATION FREQUENCY OF ITS NEOPLASTIC TISSUES WAS VERY HIGH. IN CONCLUSION, RUNX3 METHYLATION IS FREQUENTLY FOUND IN HUMAN CANCERS, INCLUDING GASTRIC CANCER, AND IS MOSTLY CANCER SPECIFIC, WITH THE EXCEPTION OF THE STOMACH, AND THUS, MIGHT BE USEFUL AS A POTENTIAL DIAGNOSTIC BIOMARKER OF CANCER.	2004	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
16  5180 23 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
17  2429 19 EPIGENETIC SILENCING OF MIR-137 IS A FREQUENT EVENT IN GASTRIC CARCINOGENESIS. MICRORNAS (MIRNA) ARE INVOLVED IN POSTTRANSCRIPTIONAL REGULATION OF GENE EXPRESSION AND ARE DYSREGULATED DURING CARCINOGENESIS. CPG ISLAND METHYLATION OF MIR-137 IS A COMMON EVENT IN DIFFERENT CANCERS; HOWEVER, THE ROLE OF MIR-137 IN GASTRIC CANCER (GC) REMAINS LARGELY UNEXPLORED. IN THIS STUDY WE AIMED TO CHARACTERIZE THE EPIGENETIC ALTERATIONS OF MIR-137 IN GASTRIC CARCINOGENESIS. WE ANALYZED TOTAL 295 TISSUES INCLUDING PAIRED PRIMARY GASTRIC CANCER (T-GC) WITH CORRESPONDING ADJACENT GASTRIC MUCOSA (N-GC), PAIRED PRIMARY COLORECTAL CANCER (CRC) TISSUES WITH CORRESPONDING NON-TUMOROUS MUCOSA, GASTRIC TISSUES FROM CONTROLS (N), AND PATIENTS WITH CHRONIC/ATROPHIC GASTRITIS (CG) WITH AND WITHOUT HELICOBACTER PYLORI INFECTION. BISULFITE PYROSEQUENCING AND TAQMAN RT-PCR WERE USED TO ANALYZE MIR-137 METHYLATION AND EXPRESSION, RESPECTIVELY. SURVIVAL DIFFERENCES WERE EVALUATED USING KAPLAN-MEIER ANALYSES. MIR-137 CPG ISLAND METHYLATION WAS MORE FREQUENT IN TUMOROUS COMPARED TO NON-TUMOROUS CONDITIONS AND HIGHER IN CRC THAN IN GC. IN COMPARISON TO N-GC, MIR 137 METHYLATION LEVEL WAS LOWER IN N AND CG TISSUES, WHICH CORRELATES WITH CORREAS CASCADE. MIR-137 METHYLATION INVERSELY CORRELATES WITH GLOBAL LINE-1 METHYLATION AND MIR-137 EXPRESSION. MIR-137 METHYLATION WAS HIGHER IN INTESTINAL TYPE GC COMPARED TO DIFFUSE ONE, AND HIGHER IN ANTRUM COMPARED TO CARDIA AND CORPUS, HOWEVER, MIR-137 METHYLATION WAS ASSOCIATED WITH WORSE PROGNOSIS IN DIFFUSE, BUT NOT IN INTESTINAL TYPE OF GC. THE EXPRESSION IN COLON WAS SIGNIFICANTLY HIGHER COMPARED TO ANY GASTRIC TISSUES SUGGESTING FUNCTIONAL DIFFERENCE. IN SUMMARY, MIR-137 METHYLATION IS A FREQUENT EVENT IN GASTROINTESTINAL CANCERS WHICH OCCURS EARLY IN STEPWISE MANNER DURING GASTRIC CARCINOGENESIS AND INVERSELY CORRELATES WITH GLOBAL METHYLATION. (C) 2015 WILEY PERIODICALS, INC.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
18  2843 25 FREQUENT CPG ISLAND METHYLATION IN PRECURSOR LESIONS AND EARLY GASTRIC ADENOCARCINOMAS. GASTRIC CARCINOGENESIS INVOLVES MULTIPLE GENETIC AND EPIGENETIC ALTERATIONS. EPIGENETIC SILENCING OF TUMOR-RELATED GENES DUE TO CPG ISLAND METHYLATION (CIM) HAS BEEN RECENTLY REPORTED IN GASTRIC CANCER, BUT THE ROLE IN PRECURSOR LESIONS IS NOT WELL UNDERSTOOD. WE ANALYSED THE METHYLATION STATUS OF THE TUMOR SUPPRESSOR GENE P16, THE DNA MISMATCH REPAIR GENE HMLH1, AND FOUR CPG ISLANDS (MINT1, MINT2, MINT25, AND MINT31) USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION IN 35 POLYPOID ADENOMAS AND 46 FLAT DYSPLASIAS UNASSOCIATED WITH CARCINOMA, 34 EARLY ADENOCARCINOMAS (T1N0M0) AND ASSOCIATED ADENOMAS/DYSPLASIAS, AND CORRESPONDING ADJACENT NON-NEOPLASTIC MUCOSA. THE EXTENT OF CIM WAS DEFINED BY THE FRACTION OF METHYLATED LOCI (METHYLATION INDEX), AND COMPARED WITH PREVIOUSLY CHARACTERIZED GENETIC ALTERATIONS (MICROSATELLITE INSTABILITY (MSI) AND APC GENE MUTATION). WE FOUND THAT METHYLATION OF P16 WAS MORE FREQUENT IN ADENOCARCINOMA-ASSOCIATED DYSPLASIAS/ADENOMAS (29%) AND ADENOCARCINOMAS (44%) AS COMPARED TO FLAT DYSPLASIAS (4%) AND ADENOMAS (18%) UNASSOCIATED WITH ADENOCARCINOMA (P=0.001). THE MEAN METHYLATION INDEX INCREASED FROM NORMAL/CHRONIC GASTRITIS (CG) MUCOSA (0.09) TO INTESTINAL METAPLASIA (IM) (0.16), FLAT DYSPLASIAS (0.40) OR POLYPOID ADENOMAS (0.41) UNASSOCIATED WITH CARCINOMA, DYSPLASIAS/ADENOMAS ASSOCIATED WITH CARCINOMA (0.44), AND ADENOCARCINOMAS (0.44). THERE WAS NO DIFFERENCE IN FREQUENCIES OF HIGH-LEVEL CPG ISLAND METHYLATION (CIM-H, METHYLATION INDEX > OR =0.5) AMONG FLAT DYSPLASIAS (50%) AND POLYPOID ADENOMAS (51%) UNASSOCIATED WITH CARCINOMA, DYSPLASIAS/ADENOMAS ASSOCIATED WITH ADENOCARCINOMA (47%), AND ADENOCARCINOMA (47%). CIM-H WAS PRESENT IN 15% OF IM, BUT NOT IN NORMAL/CG MUCOSA. THERE WAS A SIGNIFICANT CORRELATION BETWEEN METHYLATION OF HMLH1 AND HIGH-LEVEL OF MICROSATELLITE INSTABILITY (MSI-H): METHYLATION OF HMLH1 WAS PRESENT IN 71% OF MSI-H TUMORS, BUT ONLY 8% OF MSI-LOW TUMORS AND 13% OF MICROSATELLITE-STABLE TUMORS (P=0.0001). THERE WAS NO STATISTICAL DIFFERENCE BETWEEN METHYLATION INDEX AND APC MUTATION. OUR RESULTS INDICATE THAT CONCURRENT PROMOTER METHYLATION IS AN EARLY AND FREQUENT EVENT IN GASTRIC TUMORIGENESIS, INCLUDING BOTH MSI-H AND MICROSATELLITE-STABLE NEOPLASMS. METHYLATION OF THE P16 GENE MAY CONTRIBUTE TO THE MALIGNANT TRANSFORMATION OF GASTRIC PRECURSOR LESIONS.	2004	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
19  6871 24 [PATHOGENETIC IMPORTANCE OF HELICOBACTER PYLORI INFECTION]. H. PYLORI ARE ETIOLOGICAL FACTOR OF HUMAN ACUTE AND CHRONIC GASTRITIS. DEPENDING ON PATHOGENIC FACTORS OF MICROORGANISM AND POLYMORPHISM OF HUMAN GENES, CHRONIC GASTRITIS CAN BE A CAUSE FOR ULCERATIVE ENTERITIS OF THE DUODENUM OR STOMACH, GASTRIC ADENOCARCINOMA AND MALT-LYMPHOMA DEVELOPMENT. WE REVEALED GENETIC FEATURES OF BACTERIA, DETERMINED THE INTENSITY OF INFLAMMATION, SUCH AS PATHOGENIC FACTORS--CAG, PLASTIC REGION OF THE GENOME AND ADHESIN CODING GENES. EPIGENETIC CHANGES, FOR EXAMPLE THE METHYLATION OF E-CADHERIN GENE ASSOCIATED WITH H PYLORI, ARE CRUCIAL FOR CARCINOGENESIS. THEREBY, PREDISPOSITION OF CHRONIC GASTRITIS ASSOCIATED WITH H. PYLORI TO ULCERATIVE ENTERITIS OF THE DUODENUM, ULCERATIVE STOMACH DISEASE OR GASTRIC ADENOCARCINOMA DEPENDS ON TOPOGRAPHY, THE INTENSITY OF INFLAMMATION AND CHANGES OF ACID PRODUCTION IN THE STOMACH.	2012	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
20  3222 30 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