1 5435 148 RELATIVE ROLE OF METHYLATOR AND TUMOR SUPPRESSOR PATHWAYS IN ULCERATIVE COLITIS-ASSOCIATED COLON CANCER. BACKGROUND: CHRONIC ULCERATIVE COLITIS (UC) IS ASSOCIATED WITH AN INCREASED COLORECTAL CANCER RISK WHICH MAY BE SECONDARY TO REPETITIVE MUCOSAL INJURY. BOTH EPIGENETIC METHYLATION AND THE CLASSIC ADENOMA-TO-CARCINOMA SEQUENCE HAVE BEEN IMPLICATED IN THIS MALIGNANT TRANSFORMATION, BUT THE UNDERLYING MOLECULAR MECHANISMS REMAIN POORLY DEFINED. THIS STUDY COMPARES THE MOLECULAR CHARACTERISTICS OF COLITIS-ASSOCIATED AND COMMON COLORECTAL CANCERS. METHODS: NINETEEN PATIENTS WITH COLORECTAL ADENOCARCINOMAS ARISING WITHIN UC WERE MATCHED FOR AGE AND CANCER SITE WITH 54 PATIENTS WITH SPORADIC ADENOCARCINOMAS. TUMOR TISSUE WAS EXAMINED FOR BRAF MUTATIONS, CPG ISLAND METHYLATOR PHENOTYPE (CIMP), AND MLH1 PROMOTER METHYLATION. MUTATIONS OF KRAS AND P53 WERE ASSESSED BY SEQUENCING. RESULTS: PATIENT DEMOGRAPHICS WERE SIMILAR FOR THE TWO GROUPS. CIMP WAS OBSERVED IN 22% OF SPORADIC COLORECTAL CANCERS AND IN 5% OF UC CANCERS (P = 0.162). RATES OF BRAF MUTATION (4% VS 5%, P = 1.0), MLH1 METHYLATION (9% VERSUS 5%, P = 0.682), AND KRAS MUTATIONS (24% VERSUS 32%, P = 0.552) WERE SIMILAR BETWEEN THE GROUPS. HOWEVER, COLITIS-ASSOCIATED COLORECTAL CANCERS WERE MORE LIKELY TO HAVE A P53 MUTATION COMPARED TO SPORADIC ADENOCARCINOMAS (95% VERSUS 53%, P = 0.001). THE DOMINANT MUTATION FOR COLITIS-ASSOCIATED CANCERS WAS A MUTATION IN CODON 4, REPRESENTING HALF OF THE MUTATIONS. FURTHERMORE, COLITIS-ASSOCIATED CANCERS HAD A HIGHER RATE OF MUTATION IN CODON 8 (48% VERSUS 6%, P < 0.001) THAN SPORADIC COUNTERPARTS. CONCLUSIONS: UNLIKE OTHER INFLAMMATORY GASTROINTESTINAL CANCERS, COLITIS-ASSOCIATED COLORECTAL CANCERS DO NOT PREFERENTIALLY ARISE VIA A METHYLATOR PATHWAY WHEN COMPARED TO SPORADIC COLORECTAL CANCERS. CHROMOSOMAL INSTABILITY REMAINS AN IMPORTANT ETIOLOGY, BUT WITH A UNIQUE P53 FREQUENCY AND MUTATION PATTERN. 2011 2 2656 27 EPIMUTATION AND CANCER: A NEW CARCINOGENIC MECHANISM OF LYNCH SYNDROME (REVIEW). EPIMUTATION IS DEFINED AS ABNORMAL TRANSCRIPTIONAL REPRESSION OF ACTIVE GENES AND/OR ABNORMAL ACTIVATION OF USUALLY REPRESSED GENES CAUSED BY ERRORS IN EPIGENETIC GENE REPRESSION. EPIMUTATION ARISES IN SOMATIC CELLS AND THE GERMLINE, AND CONSTITUTIONAL EPIMUTATION MAY ALSO OCCUR. EPIMUTATION IS THE FIRST STEP OF TUMORIGENESIS AND CAN BE A DIRECT CAUSE OF CARCINOGENESIS. CANCERS ASSOCIATED WITH EPIMUTATION INCLUDE LYNCH SYNDROME (HEREDITARY NON-POLYPOSIS COLORECTAL CANCER, HNPCC), CHRONIC LYMPHOCYTIC LEUKEMIA, BREAST CANCER AND OVARIAN CANCER. EPIMUTATION HAS BEEN SHOWN FOR MANY TUMOR SUPPRESSOR GENES, INCLUDING RB, VHL, HMLH1, APC AND BRCA1, IN SPORADIC CANCERS. METHYLATION HAS RECENTLY BEEN SHOWN IN DNA FROM NORMAL TISSUES AND PERIPHERAL BLOOD IN CASES OF SPORADIC COLORECTAL CANCER AND MANY STUDIES SHOW CONSTITUTIVE EPIMUTATION IN CANCERS. EPIMUTATION OF DNA MISMATCH REPAIR (MMR) GENES (BRCA1, HMLH1 AND HMSH2) INVOLVED IN DEVELOPMENT FAMILIAL CANCERS HAS ALSO BEEN FOUND. THESE RESULTS HAVE LED TO A FOCUS ON EPIMUTATION AS A NOVEL ONCOGENIC MECHANISM. 2012 3 1099 46 COLONIC CARCINOGENESIS IN IBD: MOLECULAR EVENTS. PATIENTS WITH ULCERATIVE COLITIS (UC) AND CROHN'S DISEASE (CD) ARE AT INCREASED RISK OF DEVELOPING INTESTINAL CANCERS VIA MECHANISMS THAT REMAIN INCOMPLETELY UNDERSTOOD. SEVERAL EVIDENCES SUGGEST A CAUSAL LINK BETWEEN CHRONIC INFLAMMATION AND THE DEVELOPMENT OF CANCER IN THE GASTROINTESTINAL TRACT. IN FACT, PATIENTS WITH UC ARE EXPOSED TO REPEATED EPISODES OF INFLAMMATION THAT PREDISPOSE TO VARIOUS TUMORIGENIC EVENTS AND THE SEQUENCE OF THESE EVENTS ARE DIFFERENT FROM THOSE THAT CONTRIBUTE TO DEVELOP A SPORADIC COLORECTAL CANCER. IN UC CARCINOGENESIS THE EARLY EVENTS ARE REPRESENTED BY DNA METHYLATION THAT PRODUCE AN INHIBITION OF ONCO-SUPPRESSOR GENES, MUTATION OF P53, ANEUPLOIDY AND MICROSATELLITE INSTABILITY. HYPERMETHYLATION OF TUMOR SUPPRESSORS AND DNA MISMATCH REPAIR GENE PROMOTER REGIONS, IS AN EPIGENETIC MECHANISM OF GENE SILENCING THAT CONTRIBUTES TO TUMORIGENESIS AND MIGHT REPRESENT THE FIRST STEP IN INFLAMMATORY CARCINOGENESIS. P53 IS FREQUENTLY MUTATED IN THE EARLY STAGES OF UC-ASSOCIATED CANCER, IN 33-67% OF PATIENTS WITH DYSPLASIA AND IN 83-95% OF UC RELATED CANCER PATIENTS. MOREOVER, ANEUPLOIDY IS AN INDEPENDENT RISK FACTOR FOR FORTHCOMING CARCINOGENESIS IN UC FINALLY, THE INCONSISTENCY BETWEEN THE HIGH CUMULATIVE RATE OF DYSPLASIA IN UC AND THE RELATIVELY LOWER INCIDENCE OF INVASIVE CANCER RAISES THE QUESTION ABOUT THE MECHANISMS OF IMMUNOSURVEILLANCE THAT MAY PREVENT MALIGNANT PROGRESSION OF NEOPLASM IN THE COLON IN MOST CASES. CO-STIMULATORY MOLECULE CD80 UP-REGULATION IN COLONIC MUCOSA IN UC DYSPLASIA MAY BE ONE OF THESE MECHANISM. 2011 4 4638 29 NEURON-SPECIFIC METHYLOME ANALYSIS REVEALS EPIGENETIC REGULATION AND TAU-RELATED DYSFUNCTION OF BRCA1 IN ALZHEIMER'S DISEASE. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISEASE CHARACTERIZED BY PATHOLOGY OF ACCUMULATED AMYLOID BETA (ABETA) AND PHOSPHORYLATED TAU PROTEINS IN THE BRAIN. POSTMORTEM DEGRADATION AND CELLULAR COMPLEXITY WITHIN THE BRAIN HAVE LIMITED APPROACHES TO MOLECULARLY DEFINE THE CAUSAL RELATIONSHIP BETWEEN PATHOLOGICAL FEATURES AND NEURONAL DYSFUNCTION IN AD. TO OVERCOME THESE LIMITATIONS, WE ANALYZED THE NEURON-SPECIFIC DNA METHYLOME OF POSTMORTEM BRAIN SAMPLES FROM AD PATIENTS, WHICH ALLOWED DIFFERENTIALLY HYPOMETHYLATED REGION OF THE BRCA1 PROMOTER TO BE IDENTIFIED. EXPRESSION OF BRCA1 WAS SIGNIFICANTLY UP-REGULATED IN AD BRAINS, CONSISTENT WITH ITS HYPOMETHYLATION. BRCA1 PROTEIN LEVELS WERE ALSO ELEVATED IN RESPONSE TO DNA DAMAGE INDUCED BY ABETA. BRCA1 BECAME MISLOCALIZED TO THE CYTOPLASM AND HIGHLY INSOLUBLE IN A TAU-DEPENDENT MANNER, RESULTING IN DNA FRAGMENTATION IN BOTH IN VITRO CELLULAR AND IN VIVO MOUSE MODELS. BRCA1 DYSFUNCTION UNDER ABETA BURDEN IS CONSISTENT WITH CONCOMITANT DETERIORATION OF GENOMIC INTEGRITY AND SYNAPTIC PLASTICITY. THE BRCA1 PROMOTER REGION OF AD MODEL MICE BRAIN WAS SIMILARLY HYPOMETHYLATED, INDICATING AN EPIGENETIC MECHANISM UNDERLYING BRCA1 REGULATION IN AD. OUR RESULTS SUGGEST DETERIORATION OF DNA INTEGRITY AS A CENTRAL CONTRIBUTING FACTOR IN AD PATHOGENESIS. MOREOVER, THESE DATA DEMONSTRATE THE TECHNICAL FEASIBILITY OF USING NEURON-SPECIFIC DNA METHYLOME ANALYSIS TO FACILITATE DISCOVERY OF ETIOLOGICAL CANDIDATES IN SPORADIC NEURODEGENERATIVE DISEASES. 2017 5 2991 26 GENETIC INSTABILITY IN INHERITED AND SPORADIC LEUKEMIAS. GENETIC INSTABILITY DUE TO INCREASED DNA DAMAGE AND ALTERED DNA REPAIR IS OF CENTRAL SIGNIFICANCE IN THE INITIATION AND PROGRESSION OF INHERITED AND SPORADIC HUMAN LEUKEMIAS. ALTHOUGH VERY RARE, SOME INHERITED DNA REPAIR INSUFFICIENCY SYNDROMES (E.G., FANCONI ANEMIA, BLOOM'S SYNDROME) HAVE ADDED SUBSTANTIALLY TO OUR UNDERSTANDING OF CRUCIAL MECHANISMS OF LEUKEMOGENESIS IN RECENT YEARS. CONVERSELY, SPORADIC LEUKEMIAS ACCOUNT FOR THE MAIN PROPORTION OF LEUKEMIAS AND HERE DNA DAMAGING REACTIVE OXYGEN SPECIES (ROS) PLAY A CENTRAL ROLE. ALTHOUGH THE EXACT MECHANISMS OF INCREASED ROS PRODUCTION REMAIN LARGELY UNKNOWN AND NO SINGLE PATHWAY HAS BEEN DETECTED THUS FAR, SOME ONCOGENIC PROTEINS (E.G., THE ACTIVATED TYROSINE KINASES BCR-ABL1 AND FLT3-ITD) SEEM TO PLAY A KEY ROLE IN DRIVING GENETIC INSTABILITY BY INCREASED ROS GENERATION WHICH INFLUENCES THE DISEASE COURSE (E.G., BLAST CRISIS IN CHRONIC MYELOID LEUKEMIA OR RELAPSE IN FLT3-ITD POSITIVE ACUTE MYELOID LEUKEMIA). OF COURSE OTHER MECHANISMS, WHICH PROMOTE GENETIC INSTABILITY IN LEUKEMIA ALSO EXIST. A NEWLY EMERGING MECHANISM IS THE GENOME-WIDE ALTERATION OF EPIGENETIC MARKS (E.G., HYPOMETHYLATION OF HISTONE H3K79), WHICH PROMOTES CHROMOSOMAL INSTABILITY. TAKEN TOGETHER GENETIC INSTABILITY PLAYS A CRITICAL ROLE BOTH IN INHERITED AND SPORADIC LEUKEMIAS AND EMERGES AS A COMMON THEME IN BOTH INHERITED AND SPORADIC LEUKEMIAS. BEYOND ITS THEORETICAL IMPACT, THE ANALYSIS OF GENETIC INSTABILITY MAY LEAD THE WAY TO THE DEVELOPMENT OF INNOVATIVE THERAPY STRATEGIES. 2010 6 3873 33 K-RAS AND P16(INK4A)ALTERATIONS IN SPUTUM OF NSCLC PATIENTS AND IN HEAVY ASYMPTOMATIC CHRONIC SMOKERS. NSCLC RATES AMONG THE MOST FREQUENT AND LETHAL NEOPLASM WORLD-WIDE AND A SIGNIFICANT DECREASE IN MORBIDITY AND MORTALITY RELIES ONLY UPON EFFECTIVE EARLY DIAGNOSTIC STRATEGIES. WE INVESTIGATED K-RAS MUTATIONS AND P16(INK4A) HYPERMETHYLATION IN TUMOR TISSUE AND SPUTUM OF 50 PATIENTS WITH NSCLC AND CORRELATED THEM WITH SPUTUM CYTOLOGY AND WITH TUMOR STAGING, GRADING AND LOCATION, TO ASCERTAIN, IN SPUTUM, THEIR POTENTIAL DIAGNOSTIC IMPACT. THE SAME GENETIC/EPIGENETIC ABNORMALITIES AND CYTOLOGICAL FEATURES WERE ALSO EVALUATED IN SPUTUM FROM 100 CHRONIC HEAVY SMOKERS. GENETIC ANALYSIS IDENTIFIED MOLECULAR ABNORMALITIES IN 64% TUMORS (14/50 K-RAS MUTATIONS AND 24/50 P16(INK4A) HYPERMETHYLATION) AND IN 48% SPUTUM (11/50 K-RAS MUTATIONS AND 16/50 P16(INK4A) HYPERMETHYLATION). IN TUMORS K-RAS MUTATIONS AND P16(INK4A) HYPERMETHYLATION WERE MOSTLY MUTUALLY EXCLUSIVE, BEING FOUND IN THE SAME PATIENTS IN 3 CASES ONLY. GENETIC ABNORMALITIES IN SPUTUM WERE DETECTED ONLY IN MOLECULAR ABNORMAL TUMORS. MOLECULAR CHANGES IN SPUTUM HAD RATES OF DETECTION SIMILAR TO CYTOLOGY (42%) BUT THE CYTO-MOLECULAR COMBINATION INCREASED THE DIAGNOSTIC YIELD UP TO 60%. INTERESTINGLY, THE RATE OF DETECTION OF GENETIC CHANGES IN SPUTUM OF TUMORS AT EARLY STAGE (T1) WAS NOT SIGNIFICANTLY DIFFERENT FROM THAT OF TUMORS AT MORE ADVANCED STAGE (T2-T4). IN FACT K-RAS POINT MUTATIONS WERE FREQUENTLY RECOGNISED IN TUMORS AT EARLY STAGE WHILE P16(INK4A) INACTIVATION PREVAILED IN TUMORS AT ADVANCED STAGE ( P=0.0063). AS EXPECTED, DIAGNOSTIC CYTOLOGICAL FINDINGS WERE MORE FREQUENTLY FOUND IN TUMORS AT ADVANCED STAGE (P=0.004). NO CORRELATION WAS FOUND BETWEEN TUMOR GRADING AND LOCATION (CENTRAL VERSUS PERIPHERAL) AND MOLECULAR CHANGES. P16(INK4A) HYPERMETHYLATION, BUT NOT K-RAS MUTATIONS, WAS DOCUMENTED IN SPORADIC CASES OF ASYMPTOMATIC HEAVY SMOKERS (4%) WHERE IT WAS UNCOUPLED FROM CYTOLOGICAL ABNORMALITIES. IN CONCLUSION THE CYTO-MOLECULAR DIAGNOSTIC STRATEGY ADOPTED IN THIS STUDY WAS ABLE TO DETECT THE MAJORITY OF TUMORS BUT IN ORDER TO BE PROPOSED AS EFFECTIVE AND EARLY DIAGNOSTIC TOOL, THIS MOLECULAR PANEL NEEDS TO BE TESTED IN PROSPECTIVE STUDIES WITH ADEQUATE FOLLOW-UP. 2004 7 1582 28 DNA METHYLATION PROFILES IN PRECANCEROUS TISSUE AND CANCERS: CARCINOGENETIC RISK ESTIMATION AND PROGNOSTICATION BASED ON DNA METHYLATION STATUS. ALTERATIONS IN DNA METHYLATION, WHICH ARE ASSOCIATED WITH DNA METHYLTRANSFERASE ABNORMALITIES AND RESULT IN SILENCING OF TUMOR-RELATED GENES AND CHROMOSOMAL INSTABILITY, ARE INVOLVED EVEN IN PRECANCEROUS CHANGES IN VARIOUS ORGANS. DNA METHYLATION ALTERATIONS ALSO ACCOUNT FOR THE HISTOLOGICAL HETEROGENEITY AND CLINICOPATHOLOGICAL DIVERSITY OF HUMAN CANCERS. THEREFORE, WE HAVE ANALYZED DNA METHYLATION ON A GENOME-WIDE SCALE IN CLINICAL TISSUE SAMPLES. OUR APPROACH USING THE BACTERIAL ARTIFICIAL CHROMOSOME ARRAY-BASED METHYLATED CPG ISLAND AMPLIFICATION METHOD HAS REVEALED THAT DNA METHYLATION ALTERATIONS CORRELATED WITH THE FUTURE DEVELOPMENT OF MORE MALIGNANT CANCERS ARE ALREADY ACCUMULATED AT THE PRECANCEROUS STAGE IN THE KIDNEY, LIVER AND URINARY TRACT. DNA METHYLATION PROFILES AT PRECANCEROUS STAGES ARE BASICALLY INHERITED BY THE CORRESPONDING CANCERS DEVELOPING IN INDIVIDUAL PATIENTS. SUCH DNA METHYLATION ALTERATIONS MAY CONFER VULNERABILITY TO FURTHER GENETIC AND EPIGENETIC ALTERATIONS, GENERATE MORE MALIGNANT CANCERS, AND THUS DETERMINE PATIENT OUTCOME. ON THE BASIS OF BACTERIAL ARTIFICIAL CHROMOSOME ARRAY-BASED METHYLATED CPG ISLAND AMPLIFICATION DATA, INDICATORS FOR CARCINOGENETIC RISK ESTIMATION HAVE BEEN ESTABLISHED USING LIVER TISSUE SPECIMENS FROM PATIENTS WITH HEPATITIS VIRUS INFECTION, CHRONIC HEPATITIS AND LIVER CIRRHOSIS OR HISTOLOGICALLY NORMAL UROTHELIA, AND FOR PROGNOSTICATION USING BIOPSY OR SURGICALLY RESECTED SPECIMENS FROM PATIENTS WITH RENAL CELL CARCINOMA, HEPATOCELLULAR CARCINOMA AND UROTHELIAL CARCINOMA. SUCH GENOME-WIDE DNA METHYLATION PROFILING HAS NOW FIRMLY ESTABLISHED THE CLINICAL RELEVANCE OF TRANSLATIONAL EPIGENETICS. 2010 8 6746 36 WHOLE EXOME SEQUENCING OF ULCERATIVE COLITIS-ASSOCIATED COLORECTAL CANCER BASED ON NOVEL SOMATIC MUTATIONS IDENTIFIED IN CHINESE PATIENTS. BACKGROUND: CARCINOGENESIS IS A SEVERE CONSEQUENCE OF CHRONIC ULCERATIVE COLITIS. WE INVESTIGATED THE SOMATIC MUTATIONS AND PATHWAY ALTERATIONS IN ULCERATIVE COLITIS-ASSOCIATED COLORECTAL CANCER (CRC) IN CHINESE PATIENTS COMPARED WITH SPORADIC CRCS TO REVEAL POTENTIAL THERAPEUTIC TARGETS IN ULCERATIVE COLITIS-ASSOCIATED CRC. METHODS: WHOLE EXOME SEQUENCING WAS PERFORMED ON ARCHIVAL TUMOR TISSUES AND PAIRED ADJACENT NONDYSPLASTIC MUCOSA FROM 10 ULCERATIVE COLITIS-ASSOCIATED CRC PATIENTS AT A HIGH RISK OF CARCINOGENESIS. GENOMIC ALTERATION PROFILES FROM 223 PRIMARY CRCS FROM THE CANCER GENOME ATLAS SERVED AS SPORADIC CRC CONTROLS. A META-ANALYSIS WAS PERFORMED TO INVESTIGATE DIFFERENCES IN MAJOR GENETIC MUTATIONS BETWEEN ULCERATIVE COLITIS-ASSOCIATED AND CROHN'S DISEASE-ASSOCIATED CRCS. RESULTS: WE IDENTIFIED 44 NONSILENT RECURRENT SOMATIC MUTATIONS VIA WHOLE EXOME SEQUENCING, INCLUDING 25 DELETERIOUS MUTATIONS INVOLVED IN APOPTOSIS AND THE PI3K-AKT PATHWAY (COL6A3, FN1), AUTOPHAGY (ULK1), CELL ADHESION (PODXL, PTPRT, ZFHX4), AND EPIGENETIC REGULATION (ARID1A, NCOR2, KMT2D, NCOA6, MECP2, SUPT6H). IN TOTAL, 11 OF THE 25 MUTATED GENES SIGNIFICANTLY DIFFERED BETWEEN ULCERATIVE COLITIS-ASSOCIATED CRC AND SPORADIC CRC (APC, APOB, MECP2, NCOR2, NTRK2, PODXL, RABGAP1, SIK3, SUPT6H, ULK1, USP48). SOMATIC TP53 MUTATIONS OCCURRED IN 33% OF ULCERATIVE COLITIS-ASSOCIATED CRCS. SUBSEQUENT META-ANALYSIS REVEALED DISTINCT MUTATION PROFILES FOR CROHN'S DISEASE- AND ULCERATIVE COLITIS-ASSOCIATED CRCS. MUTATIONS INVOLVING THE NF-KB PATHWAY AND EPIGENETIC REGULATION WERE MORE COMMON IN ULCERATIVE COLITIS-ASSOCIATED CRCS THAN IN SPORADIC CRCS. CONCLUSION: DISTINCT GENOMIC ALTERATION PROFILES OF DELETERIOUS SOMATIC MUTATIONS WERE FOUND IN ULCERATIVE COLITIS-ASSOCIATED AND SPORADIC CRCS. MUTATIONS OF EPIGENETIC REGULATORS, SUCH AS KMT2D AND NCOA6, WERE COMMON, SUGGESTING AN EPIGENETIC PATHOMECHANISM FOR COLITIS-ASSOCIATED CARCINOMA IN CHINESE PATIENTS. 2019 9 5969 29 TERT PROMOTER MUTATIONS IN PRIMARY LIVER TUMORS. NEXT-GENERATION SEQUENCING HAS DRAWN THE GENETIC LANDSCAPE OF HEPATOCELLULAR CARCINOMA AND SEVERAL SIGNALING PATHWAYS ARE ALTERED AT THE DNA LEVEL IN TUMORS: WNT/BETA-CATENIN, CELL CYCLE REGULATOR, EPIGENETIC MODIFIER, HISTONE METHYLTRANSFERASE, OXIDATIVE STRESS, RAS/RAF/MAP KINASE AND AKT/MTOR PATHWAYS. HEPATOCARCINOGENESIS IS A MULTISTEP PROCESS STARTING WITH THE EXPOSURE TO DIFFERENT RISK FACTORS, FOLLOWED BY THE DEVELOPMENT OF A CHRONIC LIVER DISEASE AND CIRRHOSIS PRECEDE IN THE VAST MAJORITY OF THE CASES THE DEVELOPMENT OF HCC. SEVERAL LINES OF EVIDENCE HAVE UNDERLINED THE PIVOTAL ROLE OF TELOMERE MAINTENANCE IN BOTH CIRRHOSIS AND HCC PATHOGENESIS. TERT PROMOTER MUTATIONS WERE IDENTIFIED AS THE MOST FREQUENT GENETIC ALTERATIONS IN HEPATOCELLULAR CARCINOMA WITH AN OVERALL FREQUENCY AROUND 60%. MOREOVER, IN CIRRHOSIS, TERT PROMOTER MUTATIONS ARE OBSERVED AT THE EARLY STEPS OF HEPATOCARCINOGENESIS SINCE THEY ARE RECURRENTLY IDENTIFIED IN LOW-GRADE AND HIGH-GRADE DYSPLASTIC NODULES. IN CONTRAST, ACQUISITION OF GENOMIC DIVERSITY THROUGH MUTATIONS OF CLASSICAL ONCOGENES AND TUMOR SUPPRESSOR GENES (TP53, CTNNB1, ARID1A...) OCCURRED ONLY IN PROGRESSED HCC. IN NORMAL LIVER, A SUBSET OF HCC CAN DERIVED FROM THE MALIGNANT TRANSFORMATION OF HEPATOCELLULAR ADENOMA (HCA). IN HCA, CTNNB1 MUTATIONS PREDISPOSE TO TRANSFORMATION OF HCA IN HCC AND TERT PROMOTER MUTATIONS ARE REQUIRED IN MOST OF THE CASES AS A SECOND HIT FOR A FULL MALIGNANT TRANSFORMATION. ALL THESE FINDINGS HAVE REFINED OUR KNOWLEDGE OF HCC PATHOGENESIS AND HAVE POINTED TELOMERASE AS A TARGET FOR TAILORED THERAPY IN THE FUTURE. 2016 10 414 32 ANALYSIS OF PROMOTER METHYLATION IN STOOL: A NOVEL METHOD FOR THE DETECTION OF COLORECTAL CANCER. BACKGROUND & AIMS: DETECTION OF TUMOR-DERIVED DNA ALTERATIONS IN STOOL IS AN INTRIGUING NEW APPROACH WITH HIGH POTENTIAL FOR THE NONINVASIVE DETECTION OF COLORECTAL CANCER (CRC). BECAUSE OF HETEROGENEITY OF TUMORS, USUALLY MULTIPLE MARKERS DISTRIBUTED THROUGHOUT THE HUMAN GENOME NEED TO BE ANALYZED. THIS IS LABOR INTENSIVE AND DOES NOT ALLOW FOR HIGH THROUGH-PUT SCREENING. THEREFORE, MARKERS WITH HIGH SENSITIVITY AND GOOD SPECIFICITY ARE NEEDED. WE EXPLORED THE POTENTIAL OF A SINGLE EPIGENETIC MARKER IN COMPARISON WITH FECAL OCCULT BLOOD TESTING (FOBT) FOR THE DISCRIMINATION OF PATIENTS WITH CRCS AND ADENOMAS FROM THOSE WITHOUT. METHODS: METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) WAS PERFORMED TO ANALYZE HYPERMETHYLATED IN CANCER 1 (HIC1) PROMOTER METHYLATION STATUS IN A BLINDED FASHION IN STOOL SAMPLES FROM 26 PATIENTS WITH CRC, 13 WITH ADENOMA > OR =1 CM, 9 WITH HYPERPLASTIC POLYPS, 9 WITH CHRONIC INFLAMMATORY BOWEL DISEASE, AND 32 WITH ENDOSCOPICALLY NORMAL COLON. RESULTS: NINETY-SEVEN PERCENT OF THE STOOL SAMPLES CONTAINED AMPLIFIABLE DNA. FORTY-TWO PERCENT OF THE SAMPLES FROM PATIENTS WITH CRC AND 31% OF THE SAMPLES FROM PATIENTS WITH COLORECTAL ADENOMA > OR =1 CM WERE POSITIVE FOR HIC1 PROMOTER METHYLATION. NO METHYLATED HIC1 PROMOTER DNA WAS DETECTED IN THE FECAL DNA FROM PATIENTS WITH ENDOSCOPICALLY NORMAL COLON OR HYPERPLASTIC POLYPS. CONCLUSIONS: THE EPIGENETIC MARKER HIC1 PROMOTER METHYLATION CARRIES HIGH POTENTIAL FOR THE REMOTE DETECTION OF CRCS. WE POSTULATE THAT A PANEL OF MERELY A FEW GENETIC AND EPIGENETIC MARKERS WILL BE REQUIRED FOR THE HIGHLY SENSITIVE AND SPECIFIC DETECTION OF CRCS AND ADENOMAS IN FECAL SAMPLES FROM AFFECTED PATIENTS. 2005 11 563 32 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 12 3445 43 HYPERMETHYLATION OF ITGA4, TFPI2 AND VIMENTIN PROMOTERS IS INCREASED IN INFLAMED COLON TISSUE: PUTATIVE RISK MARKERS FOR COLITIS-ASSOCIATED CANCER. PURPOSE: EPIGENETIC SILENCING OF TUMOR SUPPRESSOR GENES IS INVOLVED IN EARLY TRANSFORMING EVENTS AND HAS A HIGH IMPACT ON COLORECTAL CARCINOGENESIS. LIKEWISE, COLON CANCERS THAT DERIVE FROM CHRONICALLY INFLAMED BOWEL DISEASES FREQUENTLY EXHIBIT EPIGENETIC CHANGES. BUT THERE IS LITTLE DATA ABOUT EPIGENETIC ABERRATIONS CAUSING COLORECTAL CANCER IN CHRONICALLY INFLAMED TISSUE. THE AIM OF THE PRESENT STUDY WAS TO EVALUATE THE ABERRANT GAIN OF METHYLATION IN THE GENE PROMOTERS OF VIM, TFPI2 AND ITGA4 AS PUTATIVE EARLY MARKERS IN THE DEVELOPMENT FROM INFLAMED TISSUE VIA PRECANCEROUS LESIONS TOWARD COLORECTAL CANCER. METHODS: INITIAL SCREENING OF DIFFERENT CANCER CELL LINES BY USING METHYLATION-SPECIFIC PCR REVEALED A PUTATIVE COLON CANCER-SPECIFIC METHYLATION PATTERN. ADDITIONALLY, A DEMETHYLATION ASSAY WAS PERFORMED TO INVESTIGATE THE METHYLATION-DEPENDENT GENE SILENCING OF ITGA4. THE CANDIDATE MARKERS WERE ANALYZED IN COLONIC TISSUE SPECIMENS FROM PATIENTS WITH COLORECTAL CANCER (N = 15), ADENOMAS (N = 76), SERRATED LESIONS (N = 13), CHRONIC INFLAMMATION (N = 10) AND NORMAL MUCOSAL SAMPLES (N = 9). RESULTS: A HIGH METHYLATION FREQUENCY OF VIM (55.6 %) WAS OBSERVED IN NORMAL COLON TISSUE, WHEREAS ITGA4 AND TFPI2 WERE COMPLETELY UNMETHYLATED IN CONTROLS. A SIGNIFICANT GAIN OF METHYLATION FREQUENCY WITH PROGRESSION OF DISEASE AS WELL AS AN AGE-DEPENDENT EFFECT WAS DETECTABLE FOR TFPI2. ITGA4 METHYLATION FREQUENCY WAS HIGH IN PRECANCEROUS AND CANCEROUS TISSUES AS WELL AS IN INFLAMMATORY BOWEL DISEASES (IBD). CONCLUSION: THE ALREADY ESTABLISHED METHYLATION MARKER VIM DOES NOT PERMIT A SPECIFIC AND SENSITIVE DISCRIMINATION OF HEALTHY AND NEOPLASTIC TISSUE. THE METHYLATION MARKERS ITGA4 AND TFPI2 SEEM TO BE SUITABLE RISK MARKERS FOR INFLAMMATION-ASSOCIATED COLON CANCER. 2015 13 4458 27 MOLECULAR MECHANISMS OF ALCOHOL-INDUCED COLORECTAL CARCINOGENESIS. THE ETIOLOGY OF COLORECTAL CANCER (CRC) IS COMPLEX. APPROXIMATELY, 10% OF INDIVIDUALS WITH CRC HAVE PREDISPOSING GERMLINE MUTATIONS THAT LEAD TO FAMILIAL CANCER SYNDROMES, WHEREAS MOST CRC PATIENTS HAVE SPORADIC CANCER RESULTING FROM A COMBINATION OF ENVIRONMENTAL AND GENETIC RISK FACTORS. IT HAS BECOME INCREASINGLY CLEAR THAT CHRONIC ALCOHOL CONSUMPTION IS ASSOCIATED WITH THE DEVELOPMENT OF SPORADIC CRC; HOWEVER, THE EXACT MECHANISMS BY WHICH ALCOHOL CONTRIBUTES TO COLORECTAL CARCINOGENESIS ARE LARGELY UNKNOWN. SEVERAL PROPOSED MECHANISMS FROM STUDIES IN CRC MODELS SUGGEST THAT ALCOHOL METABOLITES AND/OR ENZYMES ASSOCIATED WITH ALCOHOL METABOLISM ALTER CELLULAR REDOX BALANCE, CAUSE DNA DAMAGE, AND EPIGENETIC DYSREGULATION. IN ADDITION, ALCOHOL METABOLITES CAN CAUSE A DYSBIOTIC COLORECTAL MICROBIOME AND INTESTINAL PERMEABILITY, RESULTING IN BACTERIAL TRANSLOCATION, INFLAMMATION, AND IMMUNOSUPPRESSION. ALL OF THESE EFFECTS CAN INCREASE THE RISK OF DEVELOPING CRC. THIS REVIEW AIMS TO OUTLINE SOME OF THE MOST SIGNIFICANT AND RECENT FINDINGS ON THE MECHANISMS OF ALCOHOL IN COLORECTAL CARCINOGENESIS. WE EXAMINE THE EFFECT OF ALCOHOL ON THE GENERATION OF REACTIVE OXYGEN SPECIES, THE DEVELOPMENT OF GENOTOXIC STRESS, MODULATION OF ONE-CARBON METABOLISM, DISRUPTION OF THE MICROBIOME, AND IMMUNOSUPPRESSION. 2021 14 5276 40 PROMOTER METHYLATION OF TUMOR-RELATED GENES IN GASTRIC CARCINOGENESIS. ABERRANT PROMOTER METHYLATION AND SUBSEQUENT SILENCING OF CANCER-RELATED GENES HAS BEEN RECOGNIZED AS AN IMPORTANT PATHWAY INVOLVED IN GASTRIC CARCINOGENESIS. IN FACT, SEVERAL FACTORS ARE BELIEVED TO CONTRIBUTE TO ITS INDUCTION IN GASTRIC EPITHELIA, INCLUDING AGING, DIET, CHRONIC INFLAMMATION AND INFECTION OF HELICOBACTER PYLORI (H. PYLORI) AND EPSTEIN-BARR VIRUS (EBV). HOWEVER, THE UNDERLING MECHANISMS ARE NOT COMPLETELY IDENTIFIED, DESPITE THE BELIEF THAT INCREASED EXPRESSION OR ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), OR DECREASED DEMETHYLATION ACTIVITY MAY CONTRIBUTE TO THE EXCESSIVE METHYLATION. A GREAT NUMBER OF GENES WITH PROMOTER METHYLATION HAVE BEEN OBSERVED IN GASTRIC CANCER (GC), AMONG WHICH P16INK4A (P16), MUT L HOMOLOGUE 1 (MLH1), EPITHELIAL-CADHERIN (E-CADHERIN), RUNT-RELATED TRANSCRIPTION FACTOR 3 (RUNX3), ADENOMATOUS POLYPOSIS COLI (APC), O(6)-METHYLGUANINE-DNA METHYLTRANSFERASE (MGMT), RAS ASSOCIATION DOMAIN FAMILY 1A (RASSF1A) AND DEATH-ASSOCIATED PROTEIN KINASE (DAPK) HAVE BEEN EXTENSIVELY STUDIED. UNLIKE THE DISTINCT METHYLATION CHARACTERIZATION IN SINGLE GENES, METHYLATION ANALYSIS OF MULTIPLE GENES MAY PROVIDE MORE INFORMATION IN RISK PREDICTION, EARLY DETECTION, PROGNOSIS ASSESSMENT AND CHEMOTHERAPY CHOICE FOR GC. SPECIFICALLY, PARTICULAR MONITORING AND SCREENING SHOULD BE PERFORMED ON THOSE OVER 45 YEARS OLD, WITH PRECANCEROUS GASTRIC DISEASE OR INFECTION OF H. PYLORI OR EBV. AS AN ALTERNATIVE TO TUMOR TISSUES, METHYLATION DETECTION IN PATIENT SERA OR GASTRIC WASHES MAY ALSO BE USED IN RISK PREDICTION AND EARLY DETECTION. HOWEVER, WHAT STILL POSES A GREAT CHALLENGE AS WELL AS A PUZZLE IS THE DETERMINATION OF THE VERY GENES THAT SHOULD BE USED IN METHYLATION ANALYSIS. BECAUSE EPIGENETIC ALTERATIONS ARE NORMALLY REVERSIBLE, DRUGS OR CHEMICAL COMPOUNDS WITH DEMETHYLATING ACTIVITY, SUCH AS 5-AZA-2'-DEOXYCYTIDINE (5-AZA-DC) COULD BE USED IN THE TREATMENT OF PATIENTS WITH MULTIPLE GENE METHYLATION. IN VIEW OF THE ADVERSE EFFECTS OF 5-AZA-DC, DNMT-TARGETED STRATEGY HAS BEEN PROPOSED AND MAY PROVE TO BE MORE EFFECTIVE THAN DEMETHYLATING AGENTS. 2012 15 1431 31 DIFFERENTIAL FREQUENCIES OF P16(INK4A) PROMOTER HYPERMETHYLATION, P53 MUTATION, AND K-RAS MUTATION IN EXFOLIATIVE MATERIAL MARK THE DEVELOPMENT OF LUNG CANCER IN SYMPTOMATIC CHRONIC SMOKERS. PURPOSE: THE AIM OF THIS STUDY WAS TO INVESTIGATE THE FREQUENCY OF THREE (EPI)GENETIC ALTERATIONS (P53 AND K-RAS MUTATIONS AND P16(INK4A) PROMOTER HYPERMETHYLATION) IN SYMPTOMATIC CHRONIC SMOKERS COMPARED WITH PATIENTS WITH LUNG CANCER AND TO EVALUATE THE USE OF EXFOLIATIVE MATERIAL FOR SUCH ANALYSES. PATIENTS AND METHODS: FIFTY-ONE PATIENTS WITH HISTOLOGICALLY CONFIRMED LUNG CANCER AND 25 CHRONIC SMOKERS (> 20 PACK-YEARS) WERE INVESTIGATED FOR MUTATIONS IN THE K-RAS (CODON 12) AND P53 (CODONS 248, 249, AND 273) GENES AND FOR ALLELIC HYPERMETHYLATION OF THE P16(INK4A) GENE. DNA WAS ISOLATED FROM SPUTUM AND BILATERAL BRONCHIAL LAVAGE, AND BRUSHINGS WERE TAKEN AT BRONCHOSCOPY. RESULTS: FORTY-ONE GENETIC LESIONS WERE DETECTED WITHIN EXFOLIATIVE MATERIAL FROM THE GROUP OF 51 PATIENTS WITH LUNG CANCER AND 10 LESIONS IN THE CHRONIC SMOKER GROUP. K-RAS MUTATIONS OCCURRED EXCLUSIVELY IN THE LUNG CANCER GROUP, WHEREAS P53 MUTATIONS AND P16(INK4A) PROMOTER HYPERMETHYLATION WERE ALSO FOUND IN CHRONIC SMOKERS. THREE OF EIGHT CHRONIC SMOKERS WHO HARBORED AN (EPI)GENETIC ALTERATION WERE SUBSEQUENTLY DIAGNOSED WITH LUNG CANCER. ANALYSIS OF SPUTUM YIELDED INFORMATION EQUIVALENT TO THAT OF SAMPLES OBTAINED DURING BRONCHOSCOPY. CONCLUSION: P16(INK4A) PROMOTER HYPERMETHYLATION AND P53 MUTATIONS CAN OCCUR IN CHRONIC SMOKERS BEFORE ANY CLINICAL EVIDENCE OF NEOPLASIA AND MAY BE INDICATIVE OF AN INCREASED RISK OF DEVELOPING LUNG CANCER OR OF EARLY DISEASE. K-RAS MUTATIONS OCCUR EXCLUSIVELY IN THE PRESENCE OF CLINICALLY DETECTABLE NEOPLASTIC TRANSFORMATION. MOLECULAR ANALYSIS OF SPUTUM FOR SUCH MARKERS MAY PROVIDE AN EFFECTIVE MEANS OF SCREENING CHRONIC SMOKERS TO ENABLE EARLIER DETECTION AND THERAPEUTIC INTERVENTION OF LUNG CANCER. 2000 16 342 37 ALTERATIONS OF DNA METHYLATION ASSOCIATED WITH ABNORMALITIES OF DNA METHYLTRANSFERASES IN HUMAN CANCERS DURING TRANSITION FROM A PRECANCEROUS TO A MALIGNANT STATE. ALTERATIONS OF DNA METHYLATION ARE ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS. HUMAN CANCERS GENERALLY SHOW GLOBAL DNA HYPOMETHYLATION ACCOMPANIED BY REGION-SPECIFIC HYPERMETHYLATION. ALTERATIONS OF DNA METHYLATION MAY RESULT IN CHROMOSOMAL INSTABILITY AS A RESULT OF CHANGES IN CHROMATIN STRUCTURE. DNA HYPERMETHYLATION OF CPG ISLANDS SILENCES VARIOUS TUMOR-RELATED GENES. ALTERATIONS OF DNA METHYLATION ARE FREQUENTLY OBSERVED IN CANCERS ASSOCIATED WITH CHRONIC INFLAMMATION AND/OR PERSISTENT INFECTION WITH VIRUSES OR OTHER PATHOGENIC MICROORGANISMS, SUCH AS HEPATITIS B OR C VIRUSES, EPSTEIN-BARR VIRUS, HUMAN PAPILLOMAVIRUS AND HELICOBACTER PYLORI, OR WITH CIGARETTE SMOKING. ACCUMULATING EVIDENCE SUGGESTS THAT ALTERATIONS OF DNA METHYLATION ARE INVOLVED EVEN IN THE EARLY AND PRECANCEROUS STAGES. ON THE OTHER HAND, IN PATIENTS WITH CANCERS, ABERRANT DNA METHYLATION IS SIGNIFICANTLY ASSOCIATED WITH POORER TUMOR DIFFERENTIATION, TUMOR AGGRESSIVENESS AND POOR PROGNOSIS. PRECANCEROUS CONDITIONS SHOWING ALTERATIONS OF DNA METHYLATION MAY PROGRESS RAPIDLY AND GENERATE MORE MALIGNANT CANCERS. DNA METHYLTRANSFERASE (DNMT) 1 OVER-EXPRESSION IS NOT A SECONDARY RESULT OF INCREASED CELL PROLIFERATIVE ACTIVITY BUT IS SIGNIFICANTLY CORRELATED WITH THE CPG ISLAND METHYLATOR PHENOTYPE, WHICH IS DEFINED AS FREQUENT DNA HYPERMETHYLATION OF C-TYPE CPG ISLANDS THAT ARE USUALLY METHYLATED IN A CANCER-SPECIFIC (NOT AGE-DEPENDENT) MANNER. SPLICING ALTERATION OF DNMT3B MAY RESULT IN CHROMOSOMAL INSTABILITY THROUGH DNA HYPOMETHYLATION OF PERICENTROMERIC SATELLITE REGIONS. ALTERATION OF DNA METHYLATION MAY BECOME AN INDICATOR FOR CARCINOGENETIC RISK ESTIMATION AND EARLY DIAGNOSIS OF CANCERS AND A BIOLOGICAL PREDICTOR OF POOR PROGNOSIS IN PATIENTS WITH CANCERS. CORRECTION OF DNA METHYLATION STATUS MAY OFFER A NEW STRATEGY FOR PREVENTION AND THERAPY OF CANCERS. 2007 17 2895 23 GASTRIC CANCER DEVELOPMENT AFTER THE SUCCESSFUL ERADICATION OF HELICOBACTER PYLORI. GASTRIC CANCER (GC) DEVELOPS AS A RESULT OF INFLAMMATION-ASSOCIATED CARCINOGENESIS DUE TO HELICOBACTER PYLORI (H. PYLORI) INFECTION AND SUBSEQUENT DEFECTS IN GENETIC/EPIGENETIC EVENTS. ALTHOUGH THE INDICATION FOR ERADICATION THERAPY HAS BECOME WIDESPREAD, CLINICAL STUDIES HAVE REVEALED ITS LIMITED EFFECTS IN DECREASING THE INCIDENCE OF GC. MOREOVER, RESEARCH ON BIOPSY SPECIMENS OBTAINED BY CONVENTIONAL ENDOSCOPY HAS DEMONSTRATED THE FEASIBILITY OF THE RESTORATION OF SOME GENETIC/EPIGENETIC ALTERATIONS IN THE GASTRIC MUCOSA. PRACTICALLY, THE NUMBER OF SPORADIC CASES OF PRIMARY/METACHRONOUS GC THAT EMERGE AFTER SUCCESSFUL ERADICATION HAS INCREASED, WHILE ON-GOING GUIDELINES RECOMMEND ERADICATION THERAPY FOR PATIENTS WITH CHRONIC GASTRITIS AND THOSE WITH BACKGROUND MUCOSA AFTER ENDOSCOPIC RESECTION FOR GC. ACCORDINGLY, REGULAR SURVEILLANCE OF NUMEROUS INDIVIDUALS WHO HAVE RECEIVED ERADICATION THERAPY IS RECOMMENDED DESPITE THE LACK OF BIOMARKERS. RECENTLY, THE FOCUS HAS BEEN ON FUNCTIONAL REVERSIBILITY AFTER SUCCESSFUL ERADICATION AS ANOTHER CUE TO ELUCIDATE THE MECHANISMS OF RESTORATION AS WELL AS THOSE OF CARCINOGENESIS IN THE GASTRIC MUCOSA AFTER H. PYLORI ERADICATION. WE DEMONSTRATED THAT CONGO-RED CHROMOENDOSCOPY ENABLED THE IDENTIFICATION OF THE MULTI-FOCAL DISTRIBUTION OF FUNCTIONALLY IRREVERSIBLE MUCOSA COMPARED WITH THAT OF RESTORED MUCOSA AFTER SUCCESSFUL ERADICATION IN INDIVIDUALS AT EXTREMELY HIGH RISK FOR GC. FURTHER RESEARCH THAT USES FUNCTIONAL IMAGING MAY PROVIDE NEW INSIGHTS INTO THE MECHANISMS OF REGENERATION AND CARCINOGENESIS IN THE GASTRIC MUCOSA POST-ERADICATION AND MAY ALLOW FOR THE DEVELOPMENT OF USEFUL BIOMARKERS. 2016 18 2071 39 EPIGENETIC CONTROL OF THE E-CADHERIN GENE (CDH1) BY CPG METHYLATION IN COLECTOMY SAMPLES OF PATIENTS WITH ULCERATIVE COLITIS. E-CADHERIN BELONGS TO THE CADHERIN FAMILY OF CALCIUM-DEPENDENT CELL-ADHESION MOLECULES. THE CADHERINS PLAY AN ESSENTIAL ROLE IN BIOLOGICAL PROCESSES SUCH AS ORDERING OF CELL SORTING, MIGRATION, AND DIFFERENTIATION, AND THEIR MALFUNCTIONING IS CONNECTED WITH NEOPLASIA. NEOPLASTIC PROGRESSION IN PATIENTS WITH CHRONIC ULCERATIVE COLITIS IS CHARACTERIZED BY THE DEVELOPMENT OF EPITHELIAL DYSPLASIA. TRANSCRIPTIONAL SILENCING OF TUMOR-SUPPRESSOR GENES BY PROMOTER METHYLATION HAS BEEN OBSERVED IN DIFFERENT TYPES OF HUMAN CANCERS AND DYSPLASIA. TO EXPLORE THE MODE OF E-CADHERIN REGULATION, 156 BIOPSY SAMPLES FROM 26 PATIENTS WITH LONG-STANDING ULCERATIVE COLITIS WERE SCREENED. TO DETECT THE METHYLATION STATUS OF OUR SAMPLES, A METHYLATION-SPECIFIC PCR WAS APPLIED. METHYLATION OF THE E-CADHERIN (CDH1) PROMOTER WAS DETECTED IN 93% OF THE PATIENTS WITH DYSPLASTIC BIOPSY SAMPLES, IN CONTRAST TO ONLY 6% OF THE PATIENTS WITHOUT DYSPLASIA (P < 0.001). WE ALSO EXAMINED THE LEVEL OF SYNTHESIS OF E-CADHERIN PROTEIN BY IMMUNOHISTOCHEMICAL STAINING IN DIFFERENT PARAFFIN-EMBEDDED SAMPLES OF DYSPLASTIC AND NON-DYSPLASTIC ORIGIN IN A SUBSET OF OUR PATIENTS. SAMPLES WITH DYSPLASIA DISPLAYED REDUCED LEVELS, WHEREAS SAMPLES WITHOUT DYSPLASIA REVEALED NORMAL E-CADHERIN PROTEIN SYNTHESIS. THESE RESULTS SHOW THAT THE E-CADHERIN PROMOTER IS SUBJECTED TO EPIGENETIC CONTROL IN COLORECTAL ULCERATION. OBVIOUSLY, THIS EVENT MAY PLAY AN IMPORTANT ROLE IN THE PROGRESSION FROM CHRONIC INFLAMMATION TO COLORECTAL CANCER. FOR THIS REASON, METHYLATION OF THE CDH1 PROMOTER IS AN ATTRACTIVE NEW BIOMARKER FOR DETECTING ULCERATIVE COLITIS PATIENTS WITH A HIGH RISK FOR DEVELOPING COLORECTAL CANCERS. 2002 19 5360 33 RECENT ADVANCEMENTS IN COMPREHENSIVE GENETIC ANALYSES FOR HUMAN HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) TYPICALLY DEVELOPS IN THE LIVER WITH CHRONIC HEPATITIS AND CIRRHOSIS, AND ACTIVATION OF ONCOGENES AND INACTIVATION OF TUMOR SUPPRESSOR GENES OCCURS DURING CARCINOGENESIS VIA GENETIC AND EPIGENETIC MECHANISMS. RECENT ADVANCEMENTS IN THE DEVELOPMENT OF ANALYSES FOR EXAMINING THE CANCER GENOME HAVE REVEALED INFORMATION REGARDING GENETIC ALTERATIONS IN HCC TISSUES. ACCORDING TO PREVIOUS STUDIES, THE INCIDENCE OF RECURRENT GENETIC ALTERATIONS IN INDIVIDUAL GENES WAS THOUGHT TO BE RELATIVELY RARE AND LIMITED TO A SUBSET OF A FEW CANCER-SPECIFIC GENES SUCH AS TUMOR SUPPRESSOR P53, RB GENES AND ONCOGENES SUCH AS CTNNB1. HOWEVER, RECENT WHOLE-GENOME ANALYSES AND EXOME SEQUENCING OF TUMOR DNA HAVE REVEALED NUMEROUS NOVEL ALTERATIONS OF CANCER-RELATED GENES AND PATHWAYS CRITICAL FOR HCC DEVELOPMENT. IN ADDITION, VARIOUS RISK FACTORS FOR HCC, SUCH AS THE PRESENCE OR ABSENCE OF HEPATITIS B AND C VIRUS, MAY AFFECT THE MUTATION PROFILE OF THE CORRESPONDING CANCER GENOME. ON THE OTHER HAND, GENOME-WIDE ASSOCIATION STUDIES HAVE ALSO IDENTIFIED IMPORTANT SINGLE-NUCLEOTIDE POLYMORPHISMS INVOLVED IN HCC DEVELOPMENT, WHICH MAY ALLOW DETECTION OF A GROUP AT HIGH RISK OF HCC EMERGENCE. SUCH ANALYSES WILL CLARIFY HOW THIS MALIGNANCY CAN BE TREATED, DIAGNOSED AND PREVENTED MORE EFFECTIVELY. 2013 20 3067 34 GENOME-WIDE DNA METHYLATION PROFILES IN PRECANCEROUS CONDITIONS AND CANCERS. ALTERATIONS OF DNA METHYLATION, WHICH RESULT IN CHROMOSOMAL INSTABILITY AND SILENCING OF TUMOR-RELATED GENES, ARE AMONG THE MOST CONSISTENT EPIGENETIC CHANGES OBSERVED IN HUMAN CANCERS. ANALYSIS OF TISSUE SPECIMENS HAS REVEALED THAT DNA METHYLATION ALTERATIONS PARTICIPATE IN MULTISTAGE CARCINOGENESIS, EVEN FROM THE EARLY AND PRECANCEROUS STAGES, ESPECIALLY IN ASSOCIATION WITH CHRONIC INFLAMMATION AND/OR PERSISTENT VIRAL INFECTION, SUCH AS CHRONIC HEPATITIS OR LIVER CIRRHOSIS RESULTING FROM INFECTION WITH HEPATITIS B OR C VIRUS. DNA METHYLATION ALTERATIONS CAN ACCOUNT FOR THE HISTOLOGICAL HETEROGENEITY AND CLINICOPATHOLOGICAL DIVERSITY OF HUMAN CANCERS. OVEREXPRESSION OF DNA METHYLTRANSFERASE 1 IS NOT A SECONDARY RESULT OF INCREASED CELL PROLIFERATIVE ACTIVITY, BUT IS SIGNIFICANTLY CORRELATED WITH ACCUMULATION OF DNA HYPERMETHYLATION IN CPG ISLANDS OF TUMOR-RELATED GENES. ALTERATION OF DNA METHYLTRANSFERASE 3B SPLICING MAY RESULT IN CHROMOSOMAL INSTABILITY THROUGH DNA HYPOMETHYLATION IN PERICENTROMERIC SATELLITE REGIONS. GENOME-WIDE ANALYSIS OF DNA METHYLATION STATUS HAS REVEALED THAT THE DNA METHYLATION PROFILE AT THE PRECANCEROUS STAGE IS BASICALLY INHERITED BY THE CORRESPONDING CANCERS DEVELOPING IN INDIVIDUAL PATIENTS. DNA METHYLATION STATUS IS NOT SIMPLY ALTERED AT THE PRECANCEROUS STAGE; RATHER, DNA METHYLATION ALTERATIONS AT THE PRECANCEROUS STAGE MAY CONFER VULNERABILITY TO FURTHER GENETIC AND EPIGENETIC ALTERATIONS, GENERATE MORE MALIGNANT CANCERS, AND THUS DETERMINE PATIENT OUTCOME. THEREFORE, GENOME-WIDE DNA METHYLATION PROFILING MAY PROVIDE OPTIMAL INDICATORS FOR CARCINOGENETIC RISK ESTIMATION AND PROGNOSTICATION, AND THUS PROVIDE AN AVENUE FOR CANCER PREVENTION AND THERAPY ON AN INDIVIDUAL BASIS. 2010