1 5115 154 PORTRAIT OF DNA METHYLATED GENES PREDICTIVE OF POOR PROGNOSIS IN HEAD AND NECK CANCER AND THE IMPLICATION FOR TARGETED THERAPY. IN ADDITION TO CHRONIC INFECTION WITH HUMAN PAPILLOMA VIRUS (HPV) AND EXPOSURE TO ENVIRONMENTAL CARCINOGENS, GENETIC AND EPIGENETIC FACTORS ACT AS MAJOR RISK FACTORS FOR HEAD AND NECK CANCER (HNC) DEVELOPMENT AND PROGRESSION. HERE, WE CONDUCTED A SYSTEMATIC REVIEW IN ORDER TO ASSESS WHETHER DNA HYPERMETHYLATED GENES ARE PREDICTIVE OF HIGH RISK OF DEVELOPING HNC AND/OR IMPACT ON SURVIVAL AND OUTCOMES IN NON-HPV/NON-TOBACCO/NON-ALCOHOL ASSOCIATED HNC. WE IDENTIFIED 85 STUDIES COVERING 32,187 SUBJECTS WHERE THE RELATIONSHIP BETWEEN DNA METHYLATION, RISK FACTORS AND SURVIVAL OUTCOMES WERE ADDRESSED. CHANGES IN DNA HYPERMETHYLATION WERE IDENTIFIED FOR 120 GENES. INTERACTOME ANALYSIS REVEALED ENRICHMENT IN COMPLEX REGULATORY PATHWAYS THAT COORDINATE CELL CYCLE PROGRESSION (CCNA1, SFN, ATM, GADD45A, CDK2NA, TP53, RB1 AND RASSF1). HOWEVER, NOT ALL THESE GENES SHOWED SIGNIFICANT STATISTICAL ASSOCIATION WITH ALCOHOL CONSUMPTION, TOBACCO AND/OR HPV INFECTION IN THE MULTIVARIATE ANALYSIS. GENES WITH THE MOST ROBUST HNC RISK ASSOCIATION INCLUDED TIMP3, DCC, DAPK, CDH1, CCNA1, MGMT, P16, MINT31, CD44, RARBETA. FROM THESE CANDIDATES, WE FURTHER VALIDATED CD44 AT TRANSLATIONAL LEVEL IN AN INDEPENDENT COHORT OF 100 PATIENTS WITH TONGUE CANCER FOLLOWED-UP BEYOND 10 YEARS. CD44 EXPRESSION WAS ASSOCIATED WITH HIGH-RISK OF TUMOR RECURRENCE AND METASTASIS (P = 0.01) IN HPV-CASES. IN SUMMARY, GENES REGULATED BY METHYLATION PLAY A MODULATORY FUNCTION IN HNC SUSCEPTIBILITY AND IT REPRESENT A CRITICAL THERAPEUTIC TARGET TO MANAGE PATIENTS WITH ADVANCED DISEASE. 2021 2 59 40 A GENOME-WIDE SCREEN IDENTIFIES FREQUENTLY METHYLATED GENES IN HAEMATOLOGICAL AND EPITHELIAL CANCERS. BACKGROUND: GENETIC AS WELL AS EPIGENETIC ALTERATIONS ARE A HALLMARK OF BOTH EPITHELIAL AND HAEMATOLOGICAL MALIGNANCIES. HIGH THROUGHPUT SCREENS ARE REQUIRED TO IDENTIFY EPIGENETIC MARKERS THAT CAN BE USEFUL FOR DIAGNOSTIC AND PROGNOSTIC PURPOSES ACROSS MALIGNANCIES. RESULTS: HERE WE REPORT FOR THE FIRST TIME THE USE OF THE MIRA ASSAY (METHYLATED CPG ISLAND RECOVERY ASSAY) IN COMBINATION WITH GENOME-WIDE CPG ISLAND ARRAYS TO IDENTIFY EPIGENETIC MOLECULAR MARKERS IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) ON A GENOME-WIDE SCALE. WE IDENTIFIED 30 GENES DEMONSTRATING METHYLATION FREQUENCIES OF > OR =25% IN CHILDHOOD ALL, NINE GENES SHOWED SIGNIFICANTLY DIFFERENT METHYLATION FREQUENCIES IN B VS T-ALL. FOR MAJORITY OF THE GENES EXPRESSION COULD BE RESTORED IN METHYLATED LEUKEMIA LINES AFTER TREATMENT WITH 5-AZADC. FORTY-FOUR PERCENT OF THE GENES REPRESENT TARGETS OF THE POLYCOMB COMPLEX. IN CHRONIC MYELOID LEUKEMIA (CML) TWO OF THE GENES, (TFAP2A AND EBF2), DEMONSTRATED INCREASED METHYLATION IN BLAST CRISIS COMPARED TO CHRONIC PHASE (P < 0.05). FURTHERMORE HYPERMETHYLATION OF AN AUTOPHAGY RELATED GENE ATG16L2 WAS ASSOCIATED WITH POORER PROGNOSIS IN TERMS OF MOLECULAR RESPONSE TO IMATINIB TREATMENT. LASTLY WE DEMONSTRATED THAT TEN OF THESE GENES WERE ALSO FREQUENTLY METHYLATED IN COMMON EPITHELIAL CANCERS. CONCLUSION: IN SUMMARY WE HAVE IDENTIFIED A LARGE NUMBER OF GENES SHOWING FREQUENT METHYLATION IN CHILDHOOD ALL, METHYLATION STATUS OF TWO OF THESE GENES IS ASSOCIATED WITH ADVANCED DISEASE IN CML AND METHYLATION STATUS OF ANOTHER GENE IS ASSOCIATED WITH PROGNOSIS. IN ADDITION A SUBSET OF THESE GENES MAY ACT AS EPIGENETIC MARKERS ACROSS HEMATOLOGICAL MALIGNANCIES AS WELL AS COMMON EPITHELIAL CANCERS. 2010 3 3897 38 LARGE-SCALE ANALYSIS OF THE GENETIC AND EPIGENETIC ALTERATIONS IN HEPATOCELLULAR CARCINOMA FROM SOUTHEAST CHINA. OUR KNOWLEDGE ABOUT MOLECULAR ALTERATIONS DURING HEPATOCARCINOGENESIS IS STILL FRAGMENTARY, DUE TO LACK OF COMPREHENSIVE GENETIC AND EPIGENETIC ANALYSES IN THE SAME SET OF HEPATOCELLULAR CARCINOMAS (HCCS). IN THIS STUDY, WE CONDUCTED A LARGE-SCALE ANALYSIS, INCLUDING MUTATION SCREENING IN 50 GENES AND METHYLATION ASSAYS IN THREE GENES IN 54 PAIRS OF HCCS AND THEIR NEIGHBORING NON-CANCEROUS TISSUES. ALL SAMPLES WERE COLLECTED FROM THE RESIDENTS IN SOUTHEAST CHINA. WE FOUND HBV INFECTION AND CHRONIC HEPATITIS/CIRRHOSIS IN 83.3% AND 98.1% OF THE CASES, RESPECTIVELY. MUTATIONS WERE IDENTIFIED IN 18 OUT OF 54 (33.3%) SAMPLES, WITH P53 ALTERATIONS IN 14 CASES AND BETA-CATENIN MUTATIONS IN FOUR TUMORS. NO MUTATIONS WERE IDENTIFIED IN THE NEIGHBORING TISSUES. INTERESTINGLY, 9 OUT OF 14 (64.3%) TUMORS CARRYING P53 MUTATIONS DISPLAYED SUBSTITUTION OF SERINE BY ARGININE AT CODON 249, A CHARACTERISTIC CHANGE BELIEVED TO BE INDUCED BY AFLATOXIN-B1. FURTHERMORE, P53 MUTATION WAS SIGNIFICANTLY ASSOCIATED WITH SHORTER RECURRENCE-FREE SURVIVAL (P=0.004). THE RESULTS ALSO REVEALED ABERRANT METHYLATION IN TWO OR MORE GENES IN AS HIGH AS 90% OF TUMORS AND 40% OF ADJACENT TISSUES. THE FREQUENCY OF RASSF1A HYPERMETHYLATION WAS MUCH HIGHER THAN THAT OF P16INK4A AND HAI2 IN BOTH HCC AND NEIGHBORING TISSUES, INDICATING THAT DEREGULATION OF RASSF1A MAY PRECEDE THE OTHER TWO GENES. THESE DATA SUGGEST THAT ABERRANT METHYLATION OCCURS BEFORE MUTATION AND IS AN EARLY EVENT IN THE DEVELOPMENT OF THIS SET OF HCC. OUR FINDINGS HIGHLIGHT P53 AS A PROGNOSTIC FACTOR OF HCC AND RASSF1A AS A POTENTIAL TARGET IN PREVENTING MALIGNANT TRANSFORMATION OF HEPATOCYTES. 2008 4 2234 41 EPIGENETIC MODIFICATIONS PRECEDE MOLECULAR ALTERATIONS AND DRIVE HUMAN HEPATOCARCINOGENESIS. DEVELOPMENT OF PRIMARY LIVER CANCER IS A MULTISTAGE PROCESS. DETAILED UNDERSTANDING OF SEQUENTIAL EPIGENETIC ALTERATIONS IS LARGELY MISSING. HERE, WE PERFORMED INFINIUM HUMAN METHYLATION 450K BEADCHIPS AND RNA-SEQ ANALYSES FOR GENOME-WIDE METHYLOME AND TRANSCRIPTOME PROFILING OF CIRRHOTIC LIVER (N = 7), LOW- (N = 4) AND HIGH-GRADE (N = 9) DYSPLASTIC LESIONS, AND EARLY (N = 5) AND PROGRESSED (N = 3) HEPATOCELLULAR CARCINOMAS (HCC) SYNCHRONOUSLY DETECTED IN 8 PATIENTS WITH HCC WITH CHRONIC HEPATITIS B INFECTION. INTEGRATIVE ANALYSES OF EPIGENETICALLY DRIVEN MOLECULAR CHANGES WERE IDENTIFIED AND VALIDATED IN 2 INDEPENDENT COHORTS COMPRISING 887 HCCS. MITOCHONDRIAL DNA SEQUENCING WAS FURTHER EMPLOYED FOR CLONALITY ANALYSES, INDICATING MULTICLONAL ORIGIN IN THE MAJORITY OF INVESTIGATED HCCS. ALTERATIONS IN DNA METHYLATION PROGRESSIVELY INCREASED FROM LIVER CIRRHOSIS (CL) TO DYSPLASTIC LESIONS AND REACHED A MAXIMUM IN EARLY HCCS. ASSOCIATED EARLY ALTERATIONS IDENTIFIED BY INGENUITY PATHWAY ANALYSIS (IPA) INVOLVED APOPTOSIS, IMMUNE REGULATION, AND STEMNESS PATHWAYS, WHILE LATE CHANGES CENTERED ON CELL SURVIVAL, PROLIFERATION, AND INVASION. WE FURTHER VALIDATED 23 PUTATIVE EPIDRIVERS WITH CONCOMITANT EXPRESSION CHANGES AND ASSOCIATED WITH OVERALL SURVIVAL. FUNCTIONALLY, STRIATIN 4 (STRN4) WAS DEMONSTRATED TO BE EPIGENETICALLY REGULATED, AND INHIBITION OF STRN4 SIGNIFICANTLY SUPPRESSED TUMORIGENICITY OF HCC CELL LINES. OVERALL, APPLICATION OF INTEGRATIVE GENOMIC ANALYSES DEFINES EPIGENETIC DRIVER ALTERATIONS AND PROVIDES PROMISING TARGETS FOR POTENTIALLY NOVEL THERAPEUTIC APPROACHES. 2021 5 1587 40 DNA METHYLATION PROFILING IDENTIFIES NOVEL MARKERS OF PROGRESSION IN HEPATITIS B-RELATED CHRONIC LIVER DISEASE. BACKGROUND: CHRONIC HEPATITIS B INFECTION IS CHARACTERIZED BY HEPATIC IMMUNE AND INFLAMMATORY RESPONSE WITH CONSIDERABLE VARIATION IN THE RATES OF PROGRESSION TO CIRRHOSIS. GENETIC VARIANTS AND ENVIRONMENTAL CUES INFLUENCE PREDISPOSITION TO THE DEVELOPMENT OF CHRONIC LIVER DISEASE; HOWEVER, IT REMAINS UNKNOWN IF ABERRANT DNA METHYLATION IS ASSOCIATED WITH FIBROSIS PROGRESSION IN CHRONIC HEPATITIS B. RESULTS: TO IDENTIFY EPIGENETIC MARKS ASSOCIATED WITH INFLAMMATORY AND FIBROTIC PROCESSES OF THE HEPATITIS B-INDUCED CHRONIC LIVER DISEASE, WE CARRIED OUT HEPATIC GENOME-WIDE METHYLATION PROFILING USING ILLUMINA INFINIUM BEADARRAYS COMPARING MILD AND SEVERE FIBROTIC DISEASE IN A DISCOVERY COHORT OF 29 PATIENTS. WE OBTAINED 310 DIFFERENTIALLY METHYLATED REGIONS AND SELECTED FOUR LOCI COMPRISING THREE GENES FROM THE TOP DIFFERENTIALLY METHYLATED REGIONS: HYPERMETHYLATION OF HOXA2 AND HDAC4 ALONG WITH HYPOMETHYLATION OF PPP1R18 WERE SIGNIFICANTLY LINKED TO SEVERE FIBROSIS. WE REPLICATED THE PROMINENT METHYLATION MARKS IN AN INDEPENDENT COHORT OF 102 PATIENTS BY BISULFITE MODIFICATION AND PYROSEQUENCING. THE TIMING AND CAUSAL RELATIONSHIP OF EPIGENETIC MODIFICATIONS WITH DISEASE SEVERITY WAS FURTHER INVESTIGATED USING A COHORT OF PATIENTS WITH SERIAL BIOPSIES. CONCLUSIONS: OUR FINDINGS SUGGEST A LINKAGE OF WIDESPREAD EPIGENETIC DYSREGULATION WITH DISEASE PROGRESSION IN CHRONIC HEPATITIS B INFECTION. CPG METHYLATION AT NOVEL GENES SHEDS LIGHT ON NEW MOLECULAR PATHWAYS, WHICH CAN BE POTENTIALLY EXPLOITED AS A BIOMARKER OR TARGETED TO ATTENUATE INFLAMMATION AND FIBROSIS. 2016 6 6692 42 VARIABLE DNA METHYLATION PATTERNS ASSOCIATED WITH PROGRESSION OF DISEASE IN HEPATOCELLULAR CARCINOMAS. HEPATOCELLULAR CARCINOMA (HCC) MOST COMMONLY ARISES FROM CHRONIC INFLAMMATION DUE TO VIRAL INFECTION, AS A RESULT OF GENETIC AND EPIGENETIC ABNORMALITIES. A GLOBAL PICTURE OF EPIGENETIC CHANGES IN HCC IS LACKING. WE USED METHYLATED CPG ISLAND AMPLIFICATION MICROARRAYS (MCAMS) TO STUDY 6458 CPG ISLANDS IN HCC AND ADJACENT PRENEOPLASTIC TISSUES [CHRONIC HEPATITIS (CH) OR LIVER CIRRHOSIS (LC)] IN COMPARISON WITH NORMAL LIVER TISSUES WHERE NEITHER VIRAL INFECTION NOR HEPATITIS HAS EXISTED. MCAM IDENTIFIED 719 (11%) PROMINENT GENES OF HYPERMETHYLATION IN HCCS. HCCS ARISING FROM LC HAD SIGNIFICANTLY MORE METHYLATION THAN THOSE ARISING FROM CH (1249 GENES OR 19% VERSUS 444 GENES OR 7%, P < 0.05). THERE WERE FOUR PATTERNS OF ABERRANT METHYLATION: TYPE I (4%, E.G. MATRIX METALLOPROTEINASE 14) SHOWS A SUBSTANTIALLY HIGH METHYLATION LEVEL IN ADJACENT TISSUE AND DOES NOT INCREASE FURTHER IN CANCER. TYPE II (55%, E.G. RASSF1A) SHOWS PROGRESSIVELY INCREASING METHYLATION FROM ADJACENT TISSUE TO HCC. TYPE III (4%, E.G. GNA14) SHOWS DECREASED METHYLATION IN ADJACENT TISSUE BUT EITHER SIMILAR OR INCREASED METHYLATION IN HCC. TYPE IV (37%, E.G. CDKN2A) SHOWS LOW LEVELS OF METHYLATION IN NORMAL TISSUE AND ADJACENT TISSUE BUT HIGH LEVELS IN HCC. THESE DNA METHYLATION CHANGES WERE CONFIRMED BY QUANTITATIVE PYROSEQUENCING METHYLATION ANALYSIS IN REPRESENTATIVE 24 GENES AND WERE ANALYZED FOR CORRELATION WITH CLINICOPATHOLOGICAL PARAMETERS IN 38 PATIENTS. INTRIGUINGLY, METHYLATION IN THE TYPE IV GENES IS CHARACTERISTIC OF MODERATELY/POORLY DIFFERENTIATED CANCER. OUR GLOBAL EPIGENOME ANALYSIS REVEALS DISTINCT PATTERNS OF METHYLATION THAT ARE PROBABLY TO REPRESENT DIFFERENT PATHOPHYSIOLOGIC PROCESSES IN HCCS. 2008 7 1519 32 DNA METHYLATION AT ATP11A CG11702988 IS A BIOMARKER OF LUNG DISEASE SEVERITY IN CYSTIC FIBROSIS: A LONGITUDINAL STUDY. CYSTIC FIBROSIS (CF) IS A CHRONIC GENETIC DISEASE THAT MAINLY AFFECTS THE RESPIRATORY AND GASTROINTESTINAL SYSTEMS. NO CURATIVE TREATMENTS ARE AVAILABLE, BUT THE FOLLOW-UP IN SPECIALIZED CENTERS HAS GREATLY IMPROVED THE PATIENT LIFE EXPECTANCY. ROBUST BIOMARKERS ARE REQUIRED TO MONITOR THE DISEASE, GUIDE TREATMENTS, STRATIFY PATIENTS, AND PROVIDE OUTCOME MEASURES IN CLINICAL TRIALS. IN THE PRESENT STUDY, WE OUTLINE A STRATEGY TO SELECT PUTATIVE DNA METHYLATION BIOMARKERS OF LUNG DISEASE SEVERITY IN CYSTIC FIBROSIS PATIENTS. IN THE DISCOVERY STEP, WE SELECTED SEVEN POTENTIAL BIOMARKERS USING A GENOME-WIDE DNA METHYLATION DATASET THAT WE GENERATED IN NASAL EPITHELIAL SAMPLES FROM THE METHYLCF COHORT. IN THE REPLICATION STEP, WE ASSESSED THE SAME BIOMARKERS USING SPUTUM CELL SAMPLES FROM THE METHYLBIOMARK COHORT. OF INTEREST, DNA METHYLATION AT THE CG11702988 SITE (ATP11A GENE) POSITIVELY CORRELATED WITH LUNG FUNCTION AND BMI, AND NEGATIVELY CORRELATED WITH LUNG DISEASE SEVERITY, P. AERUGINOSA CHRONIC INFECTION, AND THE NUMBER OF EXACERBATIONS. THESE RESULTS WERE REPLICATED IN PROSPECTIVE SPUTUM SAMPLES COLLECTED AT FOUR TIME POINTS WITHIN AN 18-MONTH PERIOD AND LONGITUDINALLY. TO CONCLUDE, (I) WE IDENTIFIED A DNA METHYLATION BIOMARKER THAT CORRELATES WITH CF SEVERITY, (II) WE PROVIDED A METHOD TO EASILY ASSESS THIS BIOMARKER, AND (III) WE CARRIED OUT THE FIRST LONGITUDINAL ANALYSIS OF DNA METHYLATION IN CF PATIENTS. THIS NEW EPIGENETIC BIOMARKER COULD BE USED TO STRATIFY CF PATIENTS IN CLINICAL TRIALS. 2021 8 5277 38 PROMOTER METHYLATION PROFILE IN PRENEOPLASTIC AND NEOPLASTIC GALLBLADDER LESIONS. GALLBLADDER CARCINOMA (GBC) IS A HIGHLY MALIGNANT NEOPLASM AND REPRESENTS THE LEADING CAUSE OF CANCER DEATH IN CHILEAN WOMEN. IN ORDER TO DETERMINE THE POTENTIAL ROLE OF PROMOTER METHYLATION IN GALLBLADDER CARCINOGENESIS, WE INVESTIGATED THE FREQUENCY OF THIS EPIGENETIC MECHANISM BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) IN 35 CHRONIC CHOLECYSTITIS (CC, SEPARATED ACCORDING TO THE PRESENCE OR ABSENCE OF METAPLASIA), 19 EARLY CANCERS (MUCOSA OR MUSCULARIS PROPIA INVASION) AND 48 ADVANCED CARCINOMAS WITH INVASION OF THE GALLBLADDER SUBSEROSA (25 CASES) AND SEROSA (23 CASES). WE EXAMINED 14 GENES AND OBSERVED AN INCREASE OF MULTIGENIC METHYLATION DURING TUMORAL PROGRESSION WHICH WAS NOT SIGNIFICANTLY ASSOCIATED WITH THE PATIENT'S AGE. FOUR GENES (DAPK1, DLC1, TIMP3, AND RARBETA2) DISPLAYED A PROGRESSIVE INCREASE IN THEIR METHYLATION STATUS FROM CC WITHOUT METAPLASIA TO ADVANCED CARCINOMA INVADING THE SEROSA LAYER (P 80,000 CPGS AND SPECIFIC HYPOMETHYLATION OF THE REGION ENCODING THE HUMAN LEUKOCYTE ANTIGEN LOCUS (HLA). WE FIND THAT DECREASED HLA METHYLATION IS PREDICTIVE OF LOWER CD4 / CD8 T CELL RATIO, LINKING MOLECULAR AGING, EPIGENETIC REGULATION, AND DISEASE PROGRESSION. 2016 15 2966 31 GENETIC AND EPIGENETIC PROFILING OF CLL DISEASE PROGRESSION REVEALS LIMITED SOMATIC EVOLUTION AND SUGGESTS A RELATIONSHIP TO MEMORY-CELL DEVELOPMENT. WE EXAMINED GENETIC AND EPIGENETIC CHANGES THAT OCCUR DURING DISEASE PROGRESSION FROM INDOLENT TO AGGRESSIVE FORMS OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) USING SERIAL SAMPLES FROM 27 PATIENTS. ANALYSIS OF DNA MUTATIONS GROUPED THE LEUKEMIA CASES INTO THREE CATEGORIES: EVOLVING (26%), EXPANDING (26%) AND STATIC (47%). THUS, APPROXIMATELY THREE-QUARTERS OF THE CLL CASES HAD LITTLE TO NO GENETIC SUBCLONAL EVOLUTION. HOWEVER, WE IDENTIFIED SIGNIFICANT RECURRENT DNA METHYLATION CHANGES DURING PROGRESSION AT 4752 CPGS ENRICHED FOR REGIONS NEAR POLYCOMB 2 REPRESSIVE COMPLEX (PRC2) TARGETS. PROGRESSION-ASSOCIATED CPGS NEAR THE PRC2 TARGETS UNDERGO METHYLATION CHANGES IN THE SAME DIRECTION DURING DISEASE PROGRESSION AS DURING NORMAL DEVELOPMENT FROM NAIVE TO MEMORY B CELLS. OUR STUDY SHOWS THAT CLL PROGRESSION DOES NOT TYPICALLY OCCUR VIA SUBCLONAL EVOLUTION, BUT THAT CERTAIN CPG SITES UNDERGO RECURRENT METHYLATION CHANGES. OUR RESULTS SUGGEST CLL PROGRESSION MAY INVOLVE DEVELOPMENTAL PROCESSES SHARED IN COMMON WITH THE GENERATION OF NORMAL MEMORY B CELLS. 2015 16 3067 43 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 17 3248 30 HEPATITIS B VIRUS GENOME ASYMMETRY IN HEPATOCELLULAR CARCINOMA. BACKGROUND: THE ASSOCIATION BETWEEN HEPATITIS B VIRUS (HBV) MUTATIONS AND HEPATOCARCINOGENESIS WERE REPORTED IN THE LITERATURE. PREFERENCE FOR G OVER C IN THE LEADING DNA STRAND HAS BEEN REPORTED TO ACCOUNT FOR THE ASYMMETRY IN NUCLEOTIDE (NT) COMPOSITION. THE AIM OF THIS STUDY WAS TO ANALYZE THE COMPLETE GENOME SEQUENCE AND COMPOSITIONAL ASYMMETRY OF HBV IN DIFFERENT STAGES OF HEPATITIS B. METHODS: FULL GENOME SEQUENCING OF 24 PATIENTS WITH CHRONIC HEPATITIS B, SOME OF WHOM ALSO HAD CIRRHOSIS AND HEPATOCELLULAR CARCINOMA (HCC) WAS PERFORMED. MUTATIONS ANALYSIS WAS IMPLEMENTED IN A COMPARISON WITH A HBV GENOTYPE D REFERENCE FROM AN INTERNATIONAL DNA DATABASE. CPGPROD, A WEB-BASED APPLICATION, WAS USED TO EVALUATE CG CONTENT AND PREDICT CPG ISLANDS. RESULTS: ALL STRAINS WERE 3182 BASE PAIRS (BP) IN LENGTH, EXCEPT FOR TWO CASES OF HCC IN WHICH 9 AND 21 NT, RESPECTIVELY, WERE DELETED IN PRES2. THE GENETIC RELATEDNESS OF THESE ISOLATES WAS 97%-100%. THERE WERE COMMON CPG-RICH REGIONS IN ALL 24 ISOLATED FULL GENOME SEQUENCES, HOWEVER A STRONG NEGATIVE GC SKEW FOR FORMING A CPG ISLAND IN THE MINUS STRAND WERE EXHIBITED IN OVERLAP WITH ENHANCER I IN THREE HCC PATIENTS, A CIRRHOTIC PATIENT AND THREE WITH CHRONIC HEPATITIS. CONCLUSION: THE HIGH PERCENTAGE OF SEQUENCE IDENTITY BETWEEN HBV ISOLATES IN OUR PATIENTS DEMONSTRATES THAT GENOMIC FACTORS, EXCEPT FOR GENOTYPE, ARE INVOLVED IN HEPATOCARCINOGENESIS. VARIATIONS IN GC CONTENT WHICH WERE CAUSED BY A DIFFERENT SPECTRUM OF MUTATIONS MAY AFFECT DNA COMPOSITIONAL ASYMMETRY AND EPIGENETIC MODIFICATION OF HBV DNA IN HCC. 2012 18 1805 31 EFFECT OF SMOKING ON THE DNA METHYLATION PATTERN OF THE SOCS1 PROMOTER IN EPITHELIAL CELLS FROM THE SALIVA OF PATIENTS WITH CHRONIC PERIODONTITIS. BACKGROUND: THE AIM OF THE PRESENT STUDY WAS TO EVALUATE THE METHYLATION PATTERN IN THE SUPPRESSOR OF CYTOKINE SIGNALING 1 (SOCS1) GENE IN SMOKERS AND NON-SMOKERS WITH CHRONIC PERIODONTITIS (CP). METHODS: METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) WAS PERFORMED TO DETERMINE THE METHYLATION STATUS OF THE SOCS1 PROMOTER IN 45 SALIVA SAMPLES FROM SMOKERS AND NON-SMOKERS WITH CP. RESULTS: CELLS FROM THE SALIVA OF CP PATIENTS WHO SMOKED WERE 7.08 TIMES MORE LIKELY TO HAVE A METHYLATED SOCS1 PROMOTER THAN CELLS FROM THE SALIVA OF NON-SMOKING PATIENTS. CONCLUSIONS: SOCS1 GENE PROMOTER METHYLATION, WITH ITS POTENTIAL EFFECTS ON THE EXPRESSION OF THIS GENE, SEEMS TO BE A CONSEQUENCE OF EXPOSURE TO TOBACCO AND NOT TO PERIODONTAL DISEASE. FURTHER STUDIES ARE NEEDED TO ELUCIDATE THE RELATIONSHIP BETWEEN THE EPIGENETIC CONTROL OF IMMUNE RESPONSE GENE EXPRESSION, EXPOSURE TO ENVIRONMENTAL FACTORS, AND THE DEVELOPMENT, PROGRESSION, AND PROGNOSIS OF CP. 2019 19 6488 43 TP53 R72P POLYMORPHISM MODULATES DNA METHYLATION IN HEPATOCELLULAR CARCINOMA. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC) IS CHARACTERIZED BY WIDESPREAD EPIDEMIOLOGICAL AND MOLECULAR HETEROGENEITY. PREVIOUS WORK SHOWED THAT IN THE WESTERN PART OF NORTH AFRICA, A REGION OF LOW INCIDENCE OF HCC, MUTATIONS ARE SCARCE FOR THIS TUMOR TYPE. AS EPIGENETIC CHANGES ARE CONSIDERED POSSIBLE SURROGATES TO MUTATIONS IN HUMAN CANCERS, WE DECIDED, THUS, TO CHARACTERIZE DNA METHYLATION IN HCC FROM NORTH-AFRICAN PATIENTS. METHODS: A SET OF 11 LOCI WAS INVESTIGATED IN A SERIES OF 45 TUMOR SPECIMENS USING METHYLATION-SPECIFIC AND COMBINED-BISULFITE RESTRICTION ASSAY PCR. RESULTS OBTAINED ON CLINICAL SAMPLES WERE SUBSEQUENTLY VALIDATED IN LIVER CANCER CELL LINES. RESULTS: DNA METHYLATION AT TUMOR SUPPRESSOR LOCI IS SIGNIFICANTLY HIGHER IN SAMPLES DISPLAYING CHROMOSOME INSTABILITY. MORE IMPORTANTLY, DNA METHYLATION WAS SIGNIFICANTLY HIGHER IN ARG/ARG WHEN COMPARED TO PRO/PRO GENOTYPE CARRIERS AT CODON 72 RS1042522 OF TP53 (65% VS 20% METHYLATED LOCI, P = 0.0006), A POLYMORPHISM ALREADY KNOWN TO AFFECT SOMATIC MUTATION RATE IN HUMAN CARCINOMAS. IN VITRO EXPERIMENTS IN CELL LINES INDICATED THAT ENZYMES CONTROLLING DNA METHYLATION WERE DIFFERENTIALLY REGULATED BY CODON 72 ARG OR PRO ISOFORMS OF P53. FURTHERMORE, THE ARG72-CARRYING VERSION OF P53 WAS SHOWN TO RE-METHYLATE DNA MORE RAPIDLY THAN THE PRO-HARBORING ISOFORM. FINALLY, PRO-CARRYING CELL LINES WERE SHOWN TO BE SIGNIFICANTLY MORE RESISTANT TO DECITABINE TREATMENT (TWO-FOLD, P = 0.005). CONCLUSIONS: OUR DATA SUGGEST THAT ARG72PRO POLYMORPHISM IN A WT P53 CONTEXT MAY ACT AS A PRIMARY DRIVER OF EPIGENETIC CHANGES IN HCC. IT SUGGESTS, IN ADDITION, THAT RS1042522 GENOTYPE MAY PREDICT SENSITIVITY TO EPIGENETIC-TARGETED THERAPY. THIS MODEL OF LIVER TUMORIGENESIS THAT ASSOCIATES LOW PENETRANCE GENETIC PREDISPOSITION TO EPIGENETIC CHANGES EMERGES FROM A REGION OF LOW HCC INCIDENCE AND IT MAY, THEREFORE, APPLY ESSENTIALLY TO POPULATION LIVING IN SIMILAR AREAS. SURVEYS ON POPULATIONS SUBMITTED TO HIGHLY MUTAGENIC CONDITIONS AS PERINATALLY-ACQUIRED CHRONIC HEPATITIS B OR AFLATOXIN B1 EXPOSURE REMAINED TO BE CONDUCTED TO VALIDATE OUR OBSERVATIONS AS A GENERAL MODEL. 2015 20 342 40 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