1 3134 151 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 2 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 3 3231 38 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 4 2439 39 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 5 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 6 767 32 CD24 MEDIATES GASTRIC CARCINOGENESIS AND PROMOTES GASTRIC CANCER PROGRESSION VIA STAT3 ACTIVATION. THE DEVELOPMENT OF GASTRIC CANCER (GC) IS A COMPLEX MULTISTEP PROCESS, INCLUDING NUMEROUS GENETIC AND EPIGENETIC CHANGES. CD24 IS ASSOCIATED WITH ENHANCED INVASIVENESS OF GC AND A POOR PROGNOSIS. HOWEVER, THE MECHANISM BY WHICH CD24 INDUCES GC PROGRESSION REMAINS POORLY CHARACTERIZED. HERE, WE FOUND THAT THE EXPRESSION OF CD24 GRADUALLY INCREASED IN SAMPLES OF NORMAL GASTRIC MUCOSA, NON-ATROPHIC CHRONIC GASTRITIS, CHRONIC ATROPHIC GASTRITIS (CAG), CAG WITH INTESTINAL METAPLASIA, DYSPLASIA AND GC. MOREOVER, THE KNOCKDOWN OF CD24 INDUCED SIGNIFICANT LEVELS OF APOPTOSIS IN GC CELLS VIA THE MITOCHONDRIAL APOPTOTIC PATHWAY. CD24 MAY ALSO PROMOTE CELLULAR INVASION AND REGULATE THE EXPRESSION OF E-CADHERIN, FIBRONECTIN AND VITAMIN D RECEPTOR IN GC CELLS. THE ACTIVATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) MAY MEDIATE CD24-INDUCED GC SURVIVAL AND INVASION IN VITRO. FURTHERMORE, CD24-INDUCED GC PROGRESSION AND STAT3 ACTIVATION COULD ALSO BE DETECTED IN VIVO AND IN CLINICAL GC TISSUES SAMPLES. TAKEN TOGETHER, OUR RESULTS INDICATE THAT CD24 MEDIATES GASTRIC CARCINOGENESIS AND MAY PROMOTE GC PROGRESSION BY SUPPRESSING APOPTOSIS AND PROMOTING INVASION, WITH THE ACTIVATION OF STAT3 PLAYING A CRITICAL ROLE. 2014 7 3222 47 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 8 3227 48 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 9 2429 40 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 10 672 38 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 11 4244 46 METHYLATION STATUS OF COX-2 IN BLOOD LEUKOCYTE DNA AND RISK OF GASTRIC CANCER IN A HIGH-RISK CHINESE POPULATION. BACKGROUND: METHYLATION IS A COMMON EPIGENETIC MODIFICATION WHICH MAY PLAY A CRUCIAL ROLE IN CANCER DEVELOPMENT. TO INVESTIGATE THE ASSOCIATION BETWEEN METHYLATION OF COX-2 IN BLOOD LEUKOCYTE DNA AND RISK OF GASTRIC CANCER (GC), A NESTED CASE-CONTROL STUDY WAS CONDUCTED IN LINQU COUNTY, SHANDONG PROVINCE, A HIGH RISK AREA OF GC IN CHINA. METHODS: ASSOCIATION BETWEEN BLOOD LEUKOCYTE DNA METHYLATION OF COX-2 AND RISK OF GC WAS INVESTIGATED IN 133 GCS AND 285 SUPERFICIAL GASTRITIS (SG)/ CHRONIC ATROPHIC GASTRITIS (CAG). THE TEMPORAL TREND OF COX-2 METHYLATION LEVEL DURING GC DEVELOPMENT WAS FURTHER EXPLORED IN 74 PRE-GC AND 95 POST-GC SAMPLES (INCLUDING 31 CASES WITH BOTH PRE- AND POST-GC SAMPLES). IN ADDITION, THE ASSOCIATION OF DNA METHYLATION AND RISK OF PROGRESSION TO GC WAS EVALUATED IN 74 PRE-GC SAMPLES AND THEIR RELEVANT INTESTINAL METAPLASIA (IM)/DYSPLASIA (DYS) CONTROLS. METHYLATION LEVEL WAS DETERMINED BY QUANTITATIVE METHYLATION-SPECIFIC PCR (QMSP). ODDS RATIOS (ORS) AND 95% CONFIDENCE INTERVALS (CIS) WERE CALCULATED BY UNCONDITIONAL LOGISTIC REGRESSION ANALYSIS. RESULTS: THE MEDIANS OF COX-2 METHYLATION LEVELS WERE 2.3% AND 2.2% IN GC CASES AND CONTROLS, RESPECTIVELY. NO SIGNIFICANT ASSOCIATION WAS FOUND BETWEEN COX-2 METHYLATION AND RISK OF GC (OR, 1.15; 95% CI: 0.70-1.88). HOWEVER, THE TEMPORAL TREND ANALYSIS SHOWED THAT COX-2 METHYLATION LEVELS WERE ELEVATED AT 1-4 YEARS AHEAD OF CLINICAL GC DIAGNOSIS COMPARED WITH THE YEAR OF GC DIAGNOSIS (3.0% VS. 2.2%, P=0.01). FURTHER VALIDATION IN 31 GCS WITH BOTH PRE- AND POST-GC SAMPLES INDICATED THAT COX-2 METHYLATION LEVELS WERE SIGNIFICANTLY DECREASED AT THE YEAR OF GC DIAGNOSIS COMPARED WITH PRE-GC SAMPLES (1.5% VS. 2.5%, P=0.02). NO SIGNIFICANT ASSOCIATION BETWEEN COX-2 METHYLATION AND RISK OF PROGRESSION TO GC WAS FOUND IN SUBJECTS WITH IM (OR, 0.50; 95% CI: 0.18-1.42) OR DYS (OR, 0.70; 95% CI: 0.23-2.18). ADDITIONALLY, WE FOUND THAT ELDER PEOPLE HAD INCREASED RISK OF COX-2 HYPERMETHYLATION (OR, 1.55; 95% CI: 1.02-2.36) AND SUBJECTS WHO EVER INFECTED WITH H. PYLORI HAD DECREASED RISK OF COX-2 HYPERMETHYLATION (OR, 0.54; 95% CI: 0.34-0.88). CONCLUSIONS: COX-2 METHYLATION EXISTS IN BLOOD LEUKOCYTE DNA BUT AT A LOW LEVEL. COX-2 METHYLATION LEVELS IN BLOOD LEUKOCYTE DNA MAY CHANGE DURING GC DEVELOPMENT. 2015 12 3232 25 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 13 2870 51 FUNCTIONAL GENE POLYMORPHISMS AND EXPRESSION ALTERATION OF SELECTED MICRORNAS AND THE RISK OF VARIOUS GASTRIC LESIONS IN HELICOBACTER PYLORI-RELATED GASTRIC DISEASES. BACKGROUND: HELICOBACTER PYLORI (HP) PERSISTENT INFECTION IS AN IMPORTANT PATHOGENIC FACTOR FOR A SERIES OF CHRONIC GASTRIC DISEASES FROM CHRONIC GASTRITIS TO GASTRIC CANCER. GENETIC AND EPIGENETIC ABNORMALITIES OF MICRORNAS MAY PLAY A VITAL ROLE IN THE PATHOLOGICAL EVOLUTION OF GASTRIC MUCOSA IN HELICOBACTER PYLORI-RELATED GASTRIC DISEASES (HPGD). THIS STUDY AIMED TO INVESTIGATE THE RELATIONSHIP BETWEEN MIR-146A, MIR-196A2, MIR-149, MIR-499 AND MIR-27A GENE SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) AND THEIR EXPRESSIONS WITH PATHOLOGICAL CHANGES IN GASTRIC MUCOSA, AND TO FURTHER ANALYZE THE INTERACTIONS BETWEEN SNPS AND HP. METHODS: SUBJECTS IN THIS STUDY INCLUDED PATIENTS DIAGNOSED WITH HPGD AND HEALTHY CONTROLS. MIR-146A RS2910164, MIR-196A2 RS11614913, MIR-149 RS2292832, MIR-499 RS3746444 AND MIR-27A RS895819 WERE GENOTYPED BY DIRECT SEQUENCING. FLUORESCENCE QUANTITATIVE PCR WAS USED TO DETECT MICRORNA EXPRESSIONS. GENE-GENE AND GENE-ENVIRONMENT INTERACTIONS WERE EVALUATED BY MULTIFACTOR DIMENSIONALITY REDUCTION (MDR) METHOD. RESULTS: WE FOUND THAT FREQUENCY DISTRIBUTION OF MIR-196A2 RS11614913 CT GENOTYPE IN GASTRIC PRECANCEROUS LESION (GPL) GROUP AND GASTRIC CANCER (GC) GROUP WAS SIGNIFICANTLY HIGHER THAN NORMAL CONTROL (NOR) GROUP [ADJUSTED OR = 6.16, 95%CI (1.46-26.03); ADJUSTED OR = 11.83, 95%CI (1.65-84.72), RESPECTIVELY]. CT GENOTYPE AND C ALLELE OF MIR-27A RS895819 WERE ASSOCIATED WITH INCREASED RISK OF GC [ADJUSTED OR = 10.14, 95%CI (2.25-45.77); ADJUSTED OR = 3.71, 95%CI(1.46-9.44), RESPECTIVELY]. THE MDR ANALYSIS RESULTS SHOWED THAT THE INTERACTION BETWEEN MIR-196A2 RS11614913 AND HP WAS ASSOCIATED WITH THE RISK OF GPL (P = 0.004). MEANWHILE, THE EXPRESSION LEVEL OF MIR-196A2 IN GC GROUP WAS SIGNIFICANTLY HIGHER THAN NOR, CHRONIC INFLAMMATION (CI) AND EARLY PRECANCEROUS LESION (EPL) GROUPS AMONG HP-POSITIVE SUBJECTS. AND EXPRESSIONS OF MIR-499 AND MIR-27A IN GC GROUP WERE BOTH HIGHER THAN EPL GROUP. ALSO, MIR-27A EXPRESSION IN GC GROUP WAS HIGHER THAN CI AND GASTRIC ATROPHY (GA) GROUPS. CONCLUSION: MIR-196A2 RS11614913 AND MIR-27A RS895819 MAY AFFECT THE GENETIC SUSCEPTIBILITY TO GPL OR GC. MIR-196A2 RS11614913 AND HP HAVE A SYNERGISTIC EFFECT IN THE OCCURRENCE AND DEVELOPMENT OF GPL. THE UP-REGULATION OF MIR-499, MIR-196A2 AND MIR-27A EXPRESSION CAUSED BY HP INFECTION MAY BE AN IMPORTANT MECHANISM OF GASTRIC CARCINOGENESIS. 2022 14 3413 48 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