1  1620 116 DNA METHYLTRANSFERASE-MEDIATED TRANSCRIPTIONAL SILENCING IN MALIGNANT GLIOMA: A COMBINED WHOLE-GENOME MICROARRAY AND PROMOTER ARRAY ANALYSIS. EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IS A COMMON FEATURE IN HUMAN CANCER. PROMOTER HYPERMETHYLATION AND HISTONE DEACETYLATION ARE REVERSIBLE EPIGENETIC MECHANISMS ASSOCIATED WITH TRANSCRIPTIONAL REGULATION. DNA METHYLTRANSFERASES (DNMT1 AND DNMT3B) REGULATE AND MAINTAIN PROMOTER METHYLATION AND ARE OVEREXPRESSED IN HUMAN CANCER. WE PERFORMED WHOLE-GENOME MICROARRAY ANALYSIS TO IDENTIFY GENES WITH ALTERED EXPRESSION AFTER RNAI-INDUCED SUPPRESSION OF DNMT IN A GLIOBLASTOMA MULTIFORME (GBM) CELL LINE. WE THEN IDENTIFIED GENES WITH BOTH DECREASED EXPRESSION AND EVIDENCE OF PROMOTER CPG ISLAND HYPERMETHYLATION IN GBM TISSUE SAMPLES USING A COMBINED WHOLE-GENOME MICROARRAY TRANSCRIPTOME ANALYSIS IN CONJUNCTION WITH A PROMOTER ARRAY ANALYSIS AFTER DNA IMMUNOPRECIPITATION WITH ANTI-5-METHYLCYTIDINE. DNMT1 AND 3B KNOCKDOWN RESULTED IN THE RESTORED EXPRESSION OF 308 GENES THAT ALSO CONTAINED PROMOTER REGION HYPERMETHYLATION. OF THESE, 43 WERE ALSO FOUND TO BE DOWNREGULATED IN GBM TISSUE SAMPLES. THREE DOWNREGULATED GENES WITH HYPERMETHYLATED PROMOTERS AND RESTORED EXPRESSION IN RESPONSE TO ACUTE DNMT SUPPRESSION WERE ASSAYED FOR METHYLATION CHANGES USING BISULFITE SEQUENCE ANALYSIS OF THE PROMOTER REGION AFTER CHRONIC DNMT SUPPRESSION. RESTORATION OF GENE EXPRESSION WAS NOT ASSOCIATED WITH CHANGES IN PROMOTER REGION METHYLATION, BUT RATHER WITH CHANGES IN HISTONE METHYLATION AND CHROMATIN CONFORMATION. TWO OF THE IDENTIFIED GENES EXHIBITED GROWTH SUPPRESSIVE ACTIVITY IN IN VITRO ASSAYS. COMBINING TARGETED GENETIC MANIPULATIONS WITH COMPREHENSIVE GENOMIC AND EXPRESSION ANALYSES PROVIDES A POTENTIALLY POWERFUL NEW APPROACH FOR IDENTIFYING EPIGENETICALLY REGULATED GENES IN GBM.	2009	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
2  2326  34 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
3  6589  31 TUMOR NECROSIS FACTOR-ALPHA GENE PROMOTER METHYLATION IN JAPANESE ADULTS WITH CHRONIC PERIODONTITIS AND RHEUMATOID ARTHRITIS. BACKGROUND AND OBJECTIVE: OVER-EXPRESSION OF TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PLAYS A PATHOLOGICAL ROLE IN CHRONIC PERIODONTITIS (CP) AND RHEUMATOID ARTHRITIS (RA), WHICH MIGHT BE REGULATED BY THE EPIGENETIC MECHANISM. THE AIM OF THE PRESENT STUDY WAS TO EVALUATE WHETHER THERE IS A UNIQUE METHYLATION PROFILE OF THE TNF-ALPHA GENE PROMOTER IN BLOOD CELLS OF INDIVIDUALS WITH CP AND RA. MATERIAL AND METHODS: THE STUDY PARTICIPANTS CONSISTED OF 30 JAPANESE ADULTS WITH RA (RA GROUP), 30 RACE-MATCHED ADULTS WITH CP ONLY (CP GROUP) AND 30 RACE-MATCHED HEALTHY CONTROLS (H GROUP). GENOMIC DNA ISOLATED FROM PERIPHERAL BLOOD WAS MODIFIED BY SODIUM BISULFITE AND ANALYZED, BY DIRECT SEQUENCING, TO INVESTIGATE DNA METHYLATION OF THE TNF-ALPHA GENE PROMOTER REGION. THE LEVEL OF TNF-ALPHA PRODUCED IN MONONUCLEAR CELLS STIMULATED WITH PORPHYROMONAS GINGIVALIS LIPOPOLYSACCHARIDE WAS DETERMINED USING ELISA. RESULTS: TWELVE CYTOSINE-GUANINE DINUCLEOTIDE (CPG) MOTIFS WERE IDENTIFIED IN THE TNF-ALPHA PROMOTER FRAGMENT FROM -343 TO +57 BP. THE CP GROUP SHOWED A SIGNIFICANTLY HIGHER METHYLATION RATE AND FREQUENCY AT -72 BP THAN THE H GROUP (P < 0.01). THE RA GROUP EXHIBITED SIGNIFICANTLY HIGHER METHYLATION RATES AT SEVEN CPG MOTIFS (-302, -163, -119, -72, -49, -38 AND +10 BP), AND SIGNIFICANTLY HIGHER METHYLATION FREQUENCIES AT SIX CPG MOTIFS (-163, -119, -72, -49, -38 AND +10 BP), THAN THE H GROUP (P < 0.01 FOR ALL COMPARISONS). THE LEVELS OF TNF-ALPHA PRODUCED WERE SIGNIFICANTLY DIFFERENT BETWEEN INDIVIDUALS WITH AND WITHOUT METHYLATION AT -163 BP (P = 0.03). CONCLUSION: THESE RESULTS SUGGEST THAT THE HYPERMETHYLATED STATUS OF CPG MOTIFS IN THE TNF-ALPHA GENE PROMOTER IN BLOOD CELLS MAY BE UNIQUE TO JAPANESE ADULTS WITH CP AND RA.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
4  5116  29 POSITIVE REGULATION OF HUMAN TELOMERASE REVERSE TRANSCRIPTASE GENE EXPRESSION AND TELOMERASE ACTIVITY BY DNA METHYLATION IN PANCREATIC CANCER. AIM: WE SOUGHT TO DETERMINE THE ROLE OF TELOMERASE AND ITS CATALYTIC SUBUNIT HTERT IN PANCREATIC CANCER AND EVALUATE THE EPIGENETIC REGULATION OF HTERT BY PROMOTER METHYLATION. METHODS: THIRTY PAIRED SAMPLES OF PANCREATIC DUCTAL ADENOCARCINOMAS AND ADJACENT NORMAL TISSUE AND 12 CHRONIC PANCREATITIS SAMPLES WERE STUDIED. REVERSE TRANSCRIPTASE POLYMERASE CHAIN REACTION, TELOMERIC REPEAT AMPLIFICATION PROTOCOL ASSAY, AND METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION WERE PERFORMED TO ANALYZE HTERT EXPRESSION, TELOMERASE ACTIVITY, AND METHYLATION STATUS OF GENE PROMOTERS, RESPECTIVELY. RESULT: HTERT AND TELOMERASE ACTIVITY WERE UPREGULATED IN PANCREATIC CANCER COMPARED WITH PAIRED NORMAL TISSUES AND SAMPLES OF PANCREATITIS. HTERT EXPRESSION CORRELATED WITH TELOMERASE ACTIVITY (P \ .05) AND IN TURN CORRELATED POSITIVELY WITH HTERT PROMOTER METHYLATION (P \ .001) AND P16 PROMOTER METHYLATION. HTERT TRANSCRIPT EXPRESSION AND TELOMERASE ACTIVITY BOTH CONFERRED A WORSE OUTCOME BY UNIVARIATE AND MULTIVARIATE ANALYSIS (P \ .05). CONCLUSION: HTERT EXPRESSION AND TELOMERASE ACTIVITY ARE PREDICTORS OF POOR OUTCOME IN PANCREATIC CANCER. HTERT GENE EXPRESSION IS POSITIVELY REGULATED BY PROMOTER METHYLATION.	2009	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
5    18  32 5-AZACYTIDINE MODULATES CPG METHYLATION LEVELS OF EZH2 AND NOTCH1 IN MYELODYSPLASTIC SYNDROMES. PURPOSE: MOLECULAR MECHANISMS OF RESPONSE TO HYPOMETHYLATING AGENTS IN PATIENTS WITH MYELODYSPLASTIC SYNDROMES (MDS) AND CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) STILL REMAIN LARGELY UNKNOWN. THEREFORE, THE EFFECTS OF 5-AZACYTIDINE (AZA) ON CLONAL ARCHITECTURE AND DNA METHYLATION WERE INVESTIGATED IN THIS STUDY. METHODS: USING NEXT-GENERATION SEQUENCING (NGS), 30 MYELOID LEUKEMIA-ASSOCIATED GENES WERE ANALYZED IN 15 MDS/CMML PATIENTS WITH EXCELLENT RESPONSE TO AZA. EFFECTS ON METHYLATION LEVELS WERE ANALYZED BY QUANTITATIVE METHYLATION ANALYSIS USING PYROSEQUENCING FOR THE GLOBAL METHYLATION MARKER LINE-1 IN PATIENTS AND MYELOID CELL LINES. VARIOUS MYELOID CELL LINES AND A HEALTHY COHORT WERE SCREENED FOR METHYLATION LEVELS IN 23 GENES. SELECTED TARGETS WERE VERIFIED ON THE MDS/CMML COHORT. RESULTS: THE STUDY PRESENTED HERE SHOWED A STABLE VARIANT ALLELE FREQUENCY AND STABLE GLOBAL METHYLATION LEVELS IN RESPONDING PATIENTS. A SIGNIFICANT DEMETHYLATION OF EZH2 AND NOTCH1 WAS REVEALED IN PATIENTS WITH AZA RESPONSE. CONCLUSIONS: A RESPONSE TO AZA IS NOT ASSOCIATED WITH ERADICATION OF MALIGNANT CLONES, BUT RATHER WITH A STABILIZATION OF THE CLONAL ARCHITECTURE. WE SUGGEST CHANGES IN CPG METHYLATION LEVELS OF EZH2 AND NOTCH1 AS POTENTIAL TARGETS OF EPIGENETIC RESPONSE TO AZA TREATMENT WHICH MAY ALSO SERVE AS USEFUL BIOMARKERS AFTER CLINICAL EVALUATION.	2019	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
6  6069  37 THE DIOXIN RECEPTOR IS SILENCED BY PROMOTER HYPERMETHYLATION IN HUMAN ACUTE LYMPHOBLASTIC LEUKEMIA THROUGH INHIBITION OF SP1 BINDING. THE TRANSCRIPTION FACTOR ARYL HYDROCARBON RECEPTOR (AHR) HAS RELEVANT FUNCTIONS IN CELL PROLIFERATION. INTERESTINGLY, THE AHR CAN EITHER PROMOTE OR INHIBIT PROLIFERATION DEPENDING ON THE CELL PHENOTYPE. ALTHOUGH RECENT DATA REVEAL POTENTIAL PATHWAYS FOR AHR SIGNALING IN CELL PROLIFERATION, THE MECHANISMS THAT REGULATE ITS ACTIVITY IN TUMOR CELLS REMAIN UNKNOWN. HERE, WE HAVE ANALYZED PROMOTER HYPERMETHYLATION AS A POTENTIAL MECHANISM CONTROLLING AHR EXPRESSION IN HUMAN TUMOR CELLS. AHR PROMOTER CPG METHYLATION WAS SPORADIC IN A PANEL OF 19 TUMOR CELL LINES EXCEPT FOR THE CHRONIC MYELOID LEUKEMIA (CML) K562 AND THE ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) REH. WHEN COMPARED WITH NORMAL LYMPHOCYTES, REH HAD VERY LOW CONSTITUTIVE AHR EXPRESSION THAT COULD BE ATTRIBUTED TO PROMOTER HYPERMETHYLATION SINCE TREATMENT WITH THE DNA DEMETHYLATING AGENT 5-AZA-2'-DEOXYCITIDINE (AZA) SIGNIFICANTLY INCREASED AHR MRNA AND PROTEIN. THESE RESULTS IN LEUKEMIA-DERIVED CELL LINES WERE FURTHER CONFIRMED IN PRIMARY ALL, WHERE 33% OF THE PATIENTS (7/21) HAD AHR PROMOTER HYPERMETHYLATION. CHROMATIN IMMUNOPRECIPITATION (CHIP) SHOWED THAT METHYLATION IMPAIRED BINDING OF THE TRANSCRIPTION FACTOR SP1 TO THE AHR PROMOTER, THUS PROVIDING A MECHANISM FOR AHR DOWNREGULATION IN REH CELLS. THEREFORE, PROMOTER HYPERMETHYLATION REPRESENTS A NOVEL EPIGENETIC MECHANISM DOWNREGULATING AHR ACTIVITY IN HEMATOLOGICAL MALIGNANCIES SUCH AS ALL.	2006	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
7  3410  39 HOXA5 UNDERGOES DYNAMIC DNA METHYLATION AND TRANSCRIPTIONAL REPRESSION IN THE ADIPOSE TISSUE OF MICE EXPOSED TO HIGH-FAT DIET. BACKGROUND/OBJECTIVES: THE GENOMIC BASES OF THE ADIPOSE TISSUE ABNORMALITIES INDUCED BY CHRONIC POSITIVE CALORIE EXCESS HAVE BEEN ONLY PARTIALLY ELUCIDATED. WE ADOPTED A GENOME-WIDE APPROACH TO DIRECTLY TEST WHETHER LONG-TERM HIGH-FAT DIET (HFD) EXPOSURE AFFECTS THE DNA METHYLATION PROFILE OF THE MOUSE ADIPOSE TISSUE AND TO IDENTIFY THE FUNCTIONAL CONSEQUENCES OF THESE CHANGES. SUBJECTS/METHODS: WE HAVE USED EPIDIDYMAL FAT OF MICE FED EITHER HIGH-FAT (HFD) OR REGULAR CHOW (STD) DIET FOR 5 MONTHS AND PERFORMED GENOME-WIDE DNA METHYLATION ANALYSES BY METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING (MEDIP-SEQ). MOUSE HOMEOBOX (HOX) GENE DNA METHYLATION PCR, RT-QPCR AND BISULPHITE SEQUENCING ANALYSES WERE THEN PERFORMED. RESULTS: MICE FED THE HFD PROGRESSIVELY EXPANDED THEIR ADIPOSE MASS ACCOMPANIED BY A SIGNIFICANT DECREASE IN GLUCOSE TOLERANCE (P<0.001) AND INSULIN SENSITIVITY (P<0.05). MEDIP-SEQ DATA ANALYSIS REVEALED A UNIFORM DISTRIBUTION OF DIFFERENTIALLY METHYLATED REGIONS (DMR) THROUGH THE ENTIRE ADIPOCYTE GENOME, WITH A HIGHER NUMBER OF HYPERMETHYLATED REGIONS IN HFD MICE (P<0.005). THIS DIFFERENT METHYLATION PROFILE WAS ACCOMPANIED BY INCREASED EXPRESSION OF THE DNMT3A DNA METHYLTRANSFERASE (DNMT; P<0.05) AND THE METHYL-CPG-BINDING DOMAIN PROTEIN MBD3 (P<0.05) GENES IN HFD MICE. GENE ONTOLOGY ANALYSIS REVEALED THAT, IN THE HFD-TREATED MICE, THE HOX FAMILY OF DEVELOPMENT GENES WAS HIGHLY ENRICHED IN DIFFERENTIALLY METHYLATED GENES (P=0.008). TO VALIDATE THIS FINDING, HOXA5, WHICH IS IMPLICATED IN FAT TISSUE DIFFERENTIATION AND REMODELING, HAS BEEN SELECTED AND ANALYZED BY BISULPHITE SEQUENCING, CONFIRMING HYPERMETHYLATION IN THE ADIPOSE TISSUE FROM THE HFD MICE. HOXA5 HYPERMETHYLATION WAS ASSOCIATED WITH DOWNREGULATION OF HOXA5 MRNA AND PROTEIN EXPRESSION. FEEDING ANIMALS PREVIOUSLY EXPOSED TO THE HFD WITH A STANDARD CHOW DIET FOR TWO FURTHER MONTHS IMPROVED THE METABOLIC PHENOTYPE OF THE ANIMALS, ACCOMPANIED BY RETURN OF HOXA5 METHYLATION AND EXPRESSION LEVELS (P<0.05) TO VALUES SIMILAR TO THOSE OF THE CONTROL MICE MAINTAINED UNDER STANDARD CHOW. CONCLUSIONS: HFD INDUCES ADIPOSE TISSUE ABNORMALITIES ACCOMPANIED BY EPIGENETIC CHANGES AT THE HOXA5 ADIPOSE TISSUE REMODELING GENE.	2016	
                                                                                                                                                                       
8  2436  32 EPIGENETIC SILENCING OF SOCS3 IDENTIFIES A SUBSET OF PROSTATE CANCER WITH AN AGGRESSIVE BEHAVIOR. BACKGROUND: CHRONIC INFLAMMATION AND SUBSEQUENT TISSUTAL ALTERATIONS MAY PLAY A KEY ROLE IN PROSTATE CARCINOGENESIS. IN THIS WAY, MOLECULAR ALTERATIONS OF THE SUPPRESSOR OF CYTOKINE SIGNALING 3 (SOCS3), ONE OF THE MOST IMPORTANT INHIBITORY MOLECULE OF INFLAMMATORY SIGNAL TRANSDUCTION CIRCUITRIES, COULD CONTRIBUTE TO EXPLAIN THE PLEIOTROPIC ROLE OF INTERLEUKIN-6 (IL-6) IN THIS TYPE OF CANCER. METHODS: WE ANALYZED THE METHYLATION STATUS AND MRNA EXPRESSION OF SOCS3 IN 20 BENIGN PROSTATE HYPERPLASIAS (BPH) AND IN 51 PROSTATE CANCER SPECIMENS. WE ANALYZED THE SOCS3 METHYLATION STATUS USING METHYLATION-SPECIFIC PCR. HYPERMETHYLATION WAS CONFIRMED BY SEQUENCING AFTER SUBCLONING. EPIGENETIC SILENCING OF THIS GENE WAS ALSO DEMONSTRATED BY REAL-TIME PCR AND BY IMMUNOHISTOCHEMISTRY. RESULTS AND CORRELATION WITH CLINICAL DATA WERE STATISTICALLY ANALYZED. RESULTS: WE FOUND THAT THE PROMOTER OF SOCS3 WAS METHYLATED IN 39.2% OF PROSTATE CANCER. ON THE CONTRARY, ALL BPH AND NORMAL CONTROLS HAD AN UNMETHYLATED PATTERN. REAL-TIME ANALYSIS SHOWED THAT IN METHYLATED CASES SOCS3 MRNA EXPRESSION WAS REDUCED BY THREE AND FOUR FOLDS AS COMPARED TO BPH AND UNMETHYLATED CASES, RESPECTIVELY. INTERESTINGLY, SOCS3 MRNA LEVEL WAS HIGHER IN UNMETHYLATED PROSTATE CANCER THAN IN BPH. THE IMMUNOHISTOCHEMICAL STAINING ANALYSIS FOR SOCS 3 CONFIRMED MRNA RESULTS. MOREOVER, METHYLATION OF SOCS3 PROMOTER SIGNIFICANTLY ASSOCIATED WITH INTERMEDIATE-HIGH GRADE GLEASON SCORE (P = 0.0007) AND WITH AN UNFAVORABLE CLINICAL OUTCOME (P = 0.0019). CONCLUSIONS: OUR DATA SUGGEST THAT SOCS3 HYPERMETHYLATION MAY BE INVOLVED IN THE PATHOGENESIS OF PROSTATE CANCER AND COULD IDENTIFY A TUMOR SUBSET WITH AN AGGRESSIVE BEHAVIOR.	2011	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
9  1968  31 EPIGENETIC ALTERATION OF THE SOCS1 GENE IN CHRONIC MYELOID LEUKAEMIA. THE EXPRESSION OF THE SUPPRESSOR OF CYTOKINE SIGNALLING-1 (SOCS1) PROTEIN IS INDUCED IN RESPONSE TO STIMULATION BY SEVERAL CYTOKINES. THE INDUCED SOCS1 INHIBITS THE SIGNALLING PATHWAY THROUGH THE ASSOCIATION WITH A VARIETY OF TYROSINE KINASE PROTEINS. IN THIS STUDY, THE MUTATION ANALYSES, CPG ISLAND METHYLATION STATUS, AND THE EXPRESSION OF THE SOCS1 GENE IN 112 CHRONIC MYELOID LEUKAEMIA (CML) SAMPLES, FIVE LEUKAEMIA CELL LINES, AND 30 NORMAL CONTROLS WERE ANALYSED. NO GENETIC MUTATIONS OF SOCS1 GENE WERE NOTED IN THE CML SAMPLES. THE SOCS1 GENE WAS HYPERMETHYLATED IN 67% AND 46% OF THE BLASTIC AND CHRONIC PHASE CML SAMPLES RESPECTIVELY (P < 0.0001). HOWEVER, THERE WAS NO METHYLATION OF THE SOCS1 GENE IN NORMAL CONTROLS OR CML IN MOLECULAR REMISSION. THE METHYLATION STATUS OF THE SOCS1 GENE IS CONSISTENT WITH THE RESULTS OF THE REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION AND IMMUNOCYTOCHEMISTRY STAINING. OUR RESULTS DEMONSTRATE THAT THE SOCS1 GENE SILENCING IS CAUSED BY THE METHYLATION OF CPG ISLANDS IN CML AND IS REVERSED TO AN UNMETHYLATED STATUS IN MOLECULAR REMISSION. AS SOCS1 HAS UNIVERSAL ACTIVITY TO NEGATIVELY REGULATE SEVERAL CYTOKINE SIGNALLING PATHWAYS, THE LOSS OF THE NEGATIVE REGULATION OF CYTOKINE SIGNALLING BY THE SOCS1 MAY PLAY A ROLE IN THE PATHOGENESIS OF CML PROGRESSION.	2003	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
10  6415  31 THE STUDY OF P16 AND P15 GENE METHYLATION IN HEAD AND NECK SQUAMOUS CELL CARCINOMA AND THEIR QUANTITATIVE EVALUATION IN PLASMA BY REAL-TIME PCR. EPIGENETIC SILENCING OF THE P16 AND P15 GENES BY PROMOTER METHYLATION ARE COMMONLY OBSERVED IN HUMAN EPITHELIAL MALIGNANCIES, INCLUDING HEAD AND NECK SQUAMOUS CELL CARCINOMAS (HNSCC). IN THIS STUDY, A METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) WAS USED TO EVALUATE THE METHYLATION STATUS OF THE P16 AND P15 GENES IN 73 HNSCC SURGICAL SPECIMENS. P16 AND P15 GENE METHYLATION WAS ALSO EXAMINED IN 29 PAIRED METASTATIC LYMPH NODES AND 29 PAIRED HISTOLOGICALLY, NORMAL RESECTION MARGIN MUCOSAE. THE QUANTITY OF CELL-FREE METHYLATED P16 AND P15 DNA IN THE PLASMA SAMPLES OF 20 HNSCC PATIENTS AND 24 HEALTHY CONTROLS WAS ALSO EXAMINED USING A FLUORESCENCE-BASED REAL-TIME PCR ASSAY. THE FREQUENCIES OF P16 AND P15 METHYLATION IN THE PRIMARY TUMOUR WERE 49% AND 60%, RESPECTIVELY. CONCORDANT METHYLATION OF P16 AND P15 IN TUMOUR SAMPLES AND METASTATIC LYMPH NODES WAS FOUND IN 59 AND 38% OF CASES, RESPECTIVELY. A SIGNIFICANTLY HIGHER PREVALENCE OF P15 METHYLATION WAS FOUND IN HISTOLOGICALLY-NORMAL SURGICAL MARGIN EPITHELIA OF HNSCC PATIENTS WITH CHRONIC SMOKING AND DRINKING HABITS COMPARED WITH NON-SMOKERS AND NON-DRINKERS. IN ADDITION, METHYLATED P16 AND P15 DNA LEVELS WERE SIGNIFICANTLY HIGHER IN THE PLASMA OF HNSCC PATIENTS (MEAN 56 COPIES/ML PLASMA AND 65 COPIES/ML PLASMA, RESPECTIVELY) COMPARED WITH NORMAL CONTROLS (MEAN 6 COPIES/ML PLASMA AND 16 COPIES/ML PLASMA, RESPECTIVELY). IN CONCLUSION, PROMOTER METHYLATION OF THE P16 AND P15 GENES IS INVOLVED IN THE PATHOGENESIS OF HNSCC AND MAY BE RELATED TO CHRONIC SMOKING AND DRINKING. THE DIFFERENTIAL LEVELS OF METHYLATED P16 AND P15 DNA IN PLASMA MIGHT BE POTENTIAL USEFUL MARKERS IN SCREENING HIGH-RISK POPULATIONS FOR EARLY HNSCC AND MONITORING THEIR TREATMENT RESPONSE.	2003	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
11  1495  25 DNA HYPERMETHYLATION OF CELL CYCLE (P15 AND P16) AND APOPTOTIC (P14, P53, DAPK AND TMS1) GENES IN PERIPHERAL BLOOD OF LEUKEMIA PATIENTS. ABERRANT DNA METHYLATION OF TUMOR SUPPRESSOR GENES HAS BEEN REPORTED IN ALL MAJOR TYPES OF LEUKEMIA WITH POTENTIAL INVOLVEMENT IN THE INACTIVATION OF REGULATORY CELL CYCLE AND APOPTOSIS GENES. HOWEVER, MOST OF THE PREVIOUS REPORTS DID NOT SHOW THE EXTENT OF CONCURRENT METHYLATION OF MULTIPLE GENES IN THE FOUR LEUKEMIA TYPES. HERE, WE ANALYZED SIX KEY GENES (P14, P15, P16, P53, DAPK AND TMS1) FOR DNA METHYLATION USING METHYLATION SPECIFIC PCR TO ANALYZE PERIPHERAL BLOOD OF 78 LEUKEMIA PATIENTS (24 CML, 25 CLL, 12 AML, AND 17 ALL) AND 24 HEALTHY VOLUNTEERS. IN CML, METHYLATION WAS DETECTED FOR P15 (11%), P16 (9%), P53 (23%) AND DAPK (23%), IN CLL, P14 (25%), P15 (19%), P16 (12%), P53 (17%) AND DAPK (36%), IN AML, P14 (8%), P15 (45%), P53 (9%) AND DAPK (17%) AND IN ALL, P15 (14%), P16 (8%), AND P53 (8%). THIS STUDY HIGHLIGHTED AN ESSENTIAL ROLE OF DAPK METHYLATION IN CHRONIC LEUKEMIA IN CONTRAST TO P15 METHYLATION IN THE ACUTE CASES, WHEREAS TMS1 HYPERMETHYLATION WAS ABSENT IN ALL CASES. FURTHERMORE, HYPERMETHYLATION OF MULTIPLE GENES PER PATIENT WAS OBSERVED, WITH OBVIOUS SELECTIVENESS IN THE 9P21 CHROMOSOMAL REGION GENES (P14, P15 AND P16). INTERESTINGLY, METHYLATION OF P15 INCREASED THE RISK OF METHYLATION IN P53, AND VICE VERSA, BY FIVE FOLDS (P=0.03) INDICATING POSSIBLE SYNERGISTIC EPIGENETIC DISRUPTION OF DIFFERENT PHASES OF THE CELL CYCLE OR BETWEEN THE CELL CYCLE AND APOPTOSIS. THE INVESTIGATION OF MULTIPLE RELATIONSHIPS BETWEEN METHYLATED GENES MIGHT SHED LIGHT ON TUMOR SPECIFIC INACTIVATION OF THE CELL CYCLE AND APOPTOTIC PATHWAYS.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
12  3444  37 HYPERMETHYLATION OF E-CADHERIN IN LEUKEMIA. E-CADHERIN GENE IS OFTEN TERMED A "METASTASIS SUPPRESSOR" GENE BECAUSE THE E-CADHERIN PROTEIN CAN SUPPRESS TUMOR CELL INVASION AND METASTASIS. INACTIVATION OF THE E-CADHERIN GENE OCCURS IN UNDIFFERENTIATED SOLID TUMORS BY BOTH GENETIC AND EPIGENETIC MECHANISMS; HOWEVER, THE ROLE OF E-CADHERIN IN HEMATOLOGIC MALIGNANCIES IS ONLY NOW BEING RECOGNIZED. E-CADHERIN EXPRESSION IS ESSENTIAL FOR ERYTHROBLAST AND NORMOBLAST MATURATION, YET EXPRESSION IS REDUCED OR ABSENT IN LEUKEMIC BLAST CELLS. THIS STUDY EXAMINED THE MESSENGER RNA (MRNA) AND PROTEIN EXPRESSION OF THE E-CADHERIN GENE IN BONE MARROW AND BLOOD SAMPLES FROM NORMAL DONORS AND PATIENTS WITH LEUKEMIA. WE FOUND THAT ALL NORMAL DONOR SAMPLES EXPRESSED E-CADHERIN MRNA, WHEREAS BOTH SAMPLES OF ACUTE MYELOGENOUS LEUKEMIA AND CHRONIC LYMPHOCYTIC LEUKEMIA HAD A SIGNIFICANT REDUCTION OR ABSENCE OF EXPRESSION. HOWEVER, NORMAL BLAST COUNTERPARTS EXPRESSED ONLY A LOW LEVEL OF E-CADHERIN SURFACE PROTEIN. SODIUM BISULPHITE GENOMIC SEQUENCING WAS USED TO FULLY CHARACTERIZE THE METHYLATION PATTERNS OF THE CPG ISLAND ASSOCIATED WITH THE E-CADHERIN GENE PROMOTER IN THOSE SAMPLES WITH MATCHED DNA. ALL OF THE NORMAL CONTROL SAMPLES WERE ESSENTIALLY UNMETHYLATED; HOWEVER, 14 OF 18 (78%) OF THE LEUKEMIA SAMPLES HAD ABNORMAL HYPERMETHYLATION OF THE E-CADHERIN CPG ISLAND. IN FACT BOTH ALLELES OF THE E-CADHERIN GENE WERE OFTEN HYPERMETHYLATED. WE CONCLUDE THE E-CADHERIN GENE IS A COMMON TARGET FOR HYPERMETHYLATION IN HEMATOLOGIC MALIGNANCIES.	2000	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
13  2374  39 EPIGENETIC REGULATION OF TNFA EXPRESSION IN PERIODONTAL DISEASE. BACKGROUND: TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PLAYS A CENTRAL ROLE IN THE MOLECULAR PATHOGENESIS OF PERIODONTAL DISEASE. HOWEVER, THE EPIGENETIC REGULATION ATTRIBUTABLE TO MICROBIAL AND INFLAMMATORY SIGNALS AT THE BIOFILM-GINGIVAL INTERFACE ARE POORLY UNDERSTOOD. IN THIS STUDY, THE DNA METHYLATION ALTERATION WITHIN THE TNFA PROMOTER IN HUMAN GINGIVAL BIOPSIES FROM DIFFERENT STAGES OF PERIODONTAL DISEASE IS INVESTIGATED AND THE REGULATORY MECHANISM OF TNFA TRANSCRIPTION BY DNA METHYLATION IS EXPLORED. METHODS: GINGIVAL BIOPSIES WERE OBTAINED FROM 17 PATIENTS WITH CHRONIC PERIODONTITIS (CP) AND 18 PERIODONTALLY HEALTHY INDIVIDUALS. ANOTHER 11 INDIVIDUALS PARTICIPATED IN AN EXPERIMENTALLY INDUCED GINGIVITIS STUDY, AND GINGIVAL BIOPSIES WERE COLLECTED AT THE BASELINE, INDUCTION, AND RESOLUTION PHASE. TO CONFIRM THAT TNFA PROMOTER METHYLATION MODULATED TNFA TRANSCRIPTION, THP.1 CELLS WERE TREATED WITH A DNA METHYLTRANSFERASE INHIBITOR, 5-AZA-2-DEOXYCYTIDINE (5-AZA-2DC), AND AN RAW294.7 CELL LINE TRANSFECTED WITH A TNFA PROMOTER-SPECIFIC LUCIFERASE REPORTER SYSTEM WITH OR WITHOUT METHYLATION WAS USED. RESULTS: IN GINGIVAL BIOPSIES FROM INDIVIDUALS WITH SEVERE CP, TWO INDIVIDUAL CYTOSINE-GUANINE DINUCLEOTIDES (CPG SITES) WITHIN THE TNFA PROMOTER (AT -163 AND -161 BP) DISPLAYED INCREASED METHYLATION IN CP SAMPLES COMPARED TO THOSE WITH GINGIVAL HEALTH (16.1% +/- 5.1% VERSUS 11.0% +/- 4.6%, P = 0.02 AND 19.8% +/- 4.1% VERSUS 15.4% +/- 3.6%, P = 0.04, RESPECTIVELY). THE METHYLATION LEVEL AT -163 BP WAS INVERSELY ASSOCIATED WITH THE TRANSCRIPTION LEVEL OF TNFA (P = 0.018). HOWEVER, NO SIGNIFICANT DIFFERENCE IN THE TNFA PROMOTER METHYLATION PATTERN WAS OBSERVED IN SAMPLES BIOPSIED DURING THE INDUCTION OR RESOLUTION PHASE OF EXPERIMENTALLY INDUCED GINGIVITIS, WHICH REPRESENTED A REVERSIBLE PERIODONTAL LESION. THP.1 CELLS TREATED WITH 5-AZA-2DC DEMONSTRATED A TIME-DEPENDENT INCREASE IN TNFA MESSENGER LEVEL. IT WAS ALSO FOUND THAT THE LUCIFERASE ACTIVITY DECREASED 2.6-FOLD IN A CONSTRUCT CONTAINING AN IN VITRO METHYLATED TNFA PROMOTER WHEN COMPARED TO THE UNMETHYLATED INSERT (P = 0.03). CONCLUSION: ALTHOUGH THE BIOPSY SAMPLES REPRESENTED A MIXED CELL POPULATION, THE CHANGE IN PROMOTER METHYLATION STATUS IN CHRONIC PERIODONTAL DISEASE SUGGESTED THAT DNA METHYLATION MAY BE AN IMPORTANT REGULATORY MECHANISM IN CONTROLLING TNFA TRANSCRIPTIONAL EXPRESSION IN PERIODONTAL DISEASE.	2013	
                                        
14  3646  35 INCREASED PROTEIN EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) 1 IS SIGNIFICANTLY CORRELATED WITH THE MALIGNANT POTENTIAL AND POOR PROGNOSIS OF HUMAN HEPATOCELLULAR CARCINOMAS. ALTERATION OF DNA METHYLATION IS ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS. DNA METHYLTRANSFERASE (DNMT) 1 IS A MAJOR ENZYME INVOLVED IN ESTABLISHING GENOMIC METHYLATION PATTERNS. MOST OF THE STUDIES CONCERNING DNMT1 EXPRESSION IN HUMAN CANCERS HAVE BEEN PERFORMED ONLY AT THE MRNA LEVEL. TO DIRECTLY EXAMINE DNMT1 PROTEIN EXPRESSION LEVELS DURING HUMAN HEPATOCARCINOGENESIS, 16 HISTOLOGICALLY NORMAL LIVER TISSUES, 51 NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS, WHICH ARE CONSIDERED TO BE PRECANCEROUS CONDITIONS, AND 53 HEPATOCELLULAR CARCINOMAS (HCCS) WERE SUBJECTED TO IMMUNOHISTOCHEMIC EXAMINATION. IF MORE THAN 20% OF THE CELLS EXHIBITED NUCLEAR DNMT1 STAINING, THE TISSUE SAMPLE WAS CONSIDERED TO BE DNMT1-POSITIVE. DNMT1 IMMUNOREACTIVITY WAS OBSERVED IN 23 (43%) OF THE HCCS, BUT IN NONE (0%) OF THE HISTOLOGICALLY NORMAL LIVER OR NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS. THE INCIDENCE OF INCREASED DNMT1 PROTEIN EXPRESSION IN HCCS CORRELATED SIGNIFICANTLY WITH POOR TUMOR DIFFERENTIATION (P = 0.0006) AND PORTAL VEIN INVOLVEMENT (P = 0.0002). MOREOVER, THE RECURRENCE-FREE (P = 0.0001) AND OVERALL (P < 0.0001) SURVIVAL RATES OF PATIENTS WITH HCCS EXHIBITING INCREASED DNMT1 PROTEIN EXPRESSION WERE SIGNIFICANTLY LOWER THAN THOSE OF PATIENTS WITH HCCS THAT DID NOT EXHIBIT INCREASED EXPRESSION. INCREASED DNMT1 PROTEIN EXPRESSION MAY PLAY A CRITICAL ROLE IN THE MALIGNANT PROGRESSION OF HCCS AND BE A BIOLOGIC PREDICTOR OF BOTH HCC RECURRENCE AND A POOR PROGNOSIS IN HCC PATIENTS.	2003	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
15  5357  30 REACTIVE OXYGEN SPECIES INDUCE EPIGENETIC INSTABILITY THROUGH THE FORMATION OF 8-HYDROXYDEOXYGUANOSINE IN HUMAN HEPATOCARCINOGENESIS. CHRONIC HEPATITIS C (CHC) TRIGGERS OXIDATIVE STRESS AND CONTRIBUTES TO THE EMERGENCE OF HEPATOCELLULAR CARCINOMA (HCC). WE PREVIOUSLY REPORTED THAT TUMOR SUPPRESSOR GENE (TSG) METHYLATION IS A CRITICAL FACTOR DURING THE EARLY STAGES OF HEPATOCARCINOGENESIS. IN THIS STUDY, WE CLARIFY THE ASSOCIATION BETWEEN OXIDATIVE STRESS AND EPIGENETIC ALTERATIONS DURING HEPATOCARCINOGENESIS. WE EXAMINED DNA OXIDATION AND METHYLATION PROFILES IN 128 LIVER BIOPSY SAMPLES FROM CHC PATIENTS. THE DNA OXIDATION AND METHYLATED TSG NUMBERS WERE QUANTIFIED USING IMMUNOHISTOCHEMICAL ANALYSIS OF 8-HYDROXYDEOXYGUANOSINE (8-OHDG) AND QUANTITATIVE PCR FOR 11 TSGS, RESPECTIVELY. THE QUANTITATIVE CHROMATIN IMMUNOPRECIPITATION-PCR (CHIP-QPCR) ASSAY IN HEPG2 AND FETAL LIVER HC CELLS TREATED WITH H2O2 WAS USED TO QUANTIFY TRIMETHYL-H3K4, ACETYLATED-H4K16 (AN ACTIVE CHROMATIN MARKER), TRIMETHYL-H3K27 (A REPRESSIVE CHROMATIN MARKER) AND 8-OHDG. WE ANALYZED 30 PROMOTERS OF 25 DIFFERENT TSGS BY QPCR. THE HIGH LEVELS OF 8-OHDG WAS THE ONLY VARIABLE THAT WAS SIGNIFICANTLY ASSOCIATED WITH THE INCREASED NUMBER OF METHYLATED TSGS IN CHC (P < 0.0001). THE CHIP-QPCR REVEALED THAT AFTER H2O2 TREATMENT OF THE CELL LINES, THE 8-OHDG-BOUND PROMOTERS SHOWED A MODIFICATION FROM AN ACTIVE CHROMATIN (TRIMETHYL-H3K4 AND ACETYLATED-H4K16 DOMINANT) TO A REPRESSIVE CHROMATIN (TRIMETHYL-H3K27 DOMINANT) STATUS. WE CONCLUDE THAT OXIDATIVE STRESS ALTERS THE CHROMATIN STATUS, WHICH LEADS TO ABNORMAL METHYLATION OF TSGS, AND CONTRIBUTES TO HEPATOCARCINOGENESIS IN CHC PATIENTS.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
16  3983  38 LONG-TERM EXPOSURE TO CIGARETTE SMOKE EXTRACT INDUCES HYPOMETHYLATION AT THE RUNX3 AND IGF2-H19 LOCI IN IMMORTALIZED HUMAN UROTHELIAL CELLS. CIGARETTE SMOKING IS THE SINGLE MOST IMPORTANT EPIDEMIOLOGICAL RISK FACTOR FOR BLADDER CANCER BUT IT IS NOT KNOWN WHETHER EXPOSURE OF UROTHELIAL CELLS TO THE SYSTEMIC SOLUBLE CONTENTS OF CIGARETTE SMOKE IS DIRECTLY CAUSATIVE TO BLADDER CANCER AND THE ASSOCIATED EPIGENETIC CHANGES SUCH AS TUMOR SUPPRESSOR GENE HYPERMETHYLATION. WE UNDERTOOK THIS STUDY TO INVESTIGATE IF LONG-TERM TREATMENT OF HUMAN UROTHELIAL CELLS WITH CIGARETTE SMOKE EXTRACT (CSE) RESULTS IN TUMOR SUPPRESSOR GENE HYPERMETHYLATION, A PHENOTYPE THAT WAS PREVIOUSLY ASSOCIATED WITH LONG-TERM CONSTANT CSE TREATMENT OF AIRWAY EPITHELIAL CELLS. WE CHRONICALLY TREATED AN IMMORTALIZED HUMAN UROTHELIAL CELL LINE UROTSA WITH CSE USING A CYCLIC DAILY REGIMEN BUT THE CELLS WERE CULTURED IN CSE-FREE MEDIUM BETWEEN DAILY TREATMENTS. BISULFITE SEQUENCING AND REAL-TIME PCR ARRAY-BASED METHYLATION PROFILING WERE EMPLOYED TO EVALUATE METHYLATION CHANGES AT TUMOR SUPPRESSOR GENE LOCI IN THE CHRONICALLY CSE-TREATED CELLS VERSUS THE PASSAGE-MATCHED UNTREATED CONTROL CELLS. THE RUNX3 TUMOR SUPPRESSOR GENE PROMOTER WAS HYPOMETHYLATED WITH A SIGNIFICANT INCREASE IN PROPORTION OF THE COMPLETELY UNMETHYLATED HAPLOTYPE AFTER THE LONG-TERM CSE TREATMENT; WHEREAS RUNX3 PROMOTER HYPERMETHYLATION WAS PREVIOUSLY REPORTED FOR BLADDER CANCERS OF SMOKERS. HYPOMETHYLATION INDUCED BY THE LONG-TERM CSE TREATMENT WAS ALSO OBSERVED FOR THE IGF2-H19 LOCUS. THE METHYLATION STATUS AT THE PRSS8/PROSTASIN AND 16 ADDITIONAL LOCI HOWEVER, WAS UNAFFECTED BY THE CHRONIC CSE TREATMENT. TRANSIENT CSE TREATMENT OVER 1 DAILY REGIMEN RESULTED IN TRANSCRIPTIONAL DOWN-REGULATION OF RUNX3 AND H19, BUT ONLY THE H19 TRANSCRIPTION WAS DOWN-REGULATED IN THE CHRONICALLY CSE-TREATED UROTHELIAL CELLS. TRANSCRIPTION OF A KEY ENZYME IN ONE-CARBON METABOLISM, DIHYDROFOLATE REDUCTASE (DHFR) WAS GREATLY REDUCED BY THE LONG-TERM CSE TREATMENT, POTENTIALLY SERVING AS A MECHANISM FOR THE HYPOMETHYLATION PHENOTYPE VIA A REDUCED SUPPLY OF METHYL DONOR. IN CONCLUSION, CHRONIC CYCLIC CSE TREATMENT OF UROTHELIAL CELLS INDUCED HYPOMETHYLATION RATHER THAN HYPERMETHYLATION AT SPECIFIC LOCI.	2013	
                                                                                                                                                                                                                                                                 
17  1146  39 CONCURRENT EPIGENETIC SILENCING OF WNT/BETA-CATENIN PATHWAY INHIBITOR GENES IN B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA. BACKGROUND: THE WNT/BETA-CATENIN SIGNALLING IS ABERRANTLY ACTIVATED IN PRIMARY B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL). EPIGENETIC SILENCING OF PATHWAY INHIBITOR GENES MAY BE A MECHANISM FOR ITS ACTIVATION. IN THIS STUDY, WE INVESTIGATED SYSTEMATICALLY AND QUANTITATIVELY THE METHYLATION STATUS OF 12 WNT/BETA-CATENIN PATHWAY INHIBITOR GENES - CDH1, DACT1, DKK1, DKK2, DKK3, DKK4, SFRP1, SFRP2, SFRP3, SFRP4, SFRP5 AND WIF1 - IN THE CELL LINES EHEB AND MEC-1 AS WELL AS PATIENT SAMPLES. METHODS: QUANTIFICATION OF DNA METHYLATION WAS PERFORMED BY MEANS OF BISULPHITE PYROSEQUENCING AND CONFIRMED BY BISULPHITE SANGER SEQUENCING. GENE EXPRESSION WAS ANALYSED BY QPCR USING GAPDH AS INTERNAL CONTROL. E-CADHERIN AND BETA-CATENIN PROTEIN QUANTIFICATION WAS CARRIED OUT BY MICROSPHERE-BASED IMMUNOASSAYS. METHYLATION DIFFERENCES OBSERVED BETWEEN THE PATIENT AND CONTROL GROUPS WERE TESTED USING GENERALISED LEAST SQUARES MODELS. RESULTS: FOR 10 GENES, A HIGHER METHYLATION LEVEL WAS OBSERVED IN TUMOUR MATERIAL. ONLY DKK4 EXHIBITED SIMILARLY HIGH METHYLATION LEVELS IN BOTH TUMOUR AND NORMAL SPECIMENS, WHILE DACT1 WAS ALWAYS ESSENTIALLY UNMETHYLATED. HOWEVER, ALSO FOR THESE INHIBITORS, TREATMENT OF CELLS WITH THE DEMETHYLATING AGENT 5-AZA-2 -DEOXYCYTIDINE RESULTED IN AN INDUCTION OF THEIR EXPRESSION, AS SHOWN BY QUANTITATIVE PCR, SUGGESTING AN INDIRECT EPIGENETIC CONTROL OF ACTIVITY. WHILE THE DEGREE OF DEMETHYLATION AND ITS TRANSCRIPTIONAL CONSEQUENCES DIFFERED BETWEEN THE GENES, THERE WAS AN OVERALL HIGH CORRELATION OF DEMETHYLATION AND INCREASED ACTIVITY. PROTEIN EXPRESSION STUDIES REVEALED THAT NO CONSTITUTIVE WNT/BETA-CATENIN SIGNALLING OCCURRED IN THE CELL LINES, WHICH IS IN DISCREPANCY WITH RESULTS FROM PRIMARY CLL. HOWEVER, TREATMENT WITH 5-AZA-2 -DEOXYCYTIDINE CAUSED ACCUMULATION OF BETA-CATENIN. SIMULTANEOUSLY, E-CADHERIN EXPRESSION WAS STRONGLY INDUCED, LEADING TO THE FORMATION OF A COMPLEX WITH BETA-CATENIN AND THUS DEMONSTRATING ITS EPIGENETICALLY REGULATED INHIBITION EFFECT. CONCLUSIONS: THE RESULTS SUGGEST AN EPIGENETIC SILENCING MECHANISM OF THE WNT/BETA-CATENIN PATHWAY INHIBITOR GENES IN CLL. HYPERMETHYLATION AND SILENCING OF FUNCTIONALLY RELATED GENES MAY NOT BE COMPLETELY STOCHASTIC BUT RESULT FROM THE TUMOUR EPIGENOME REPROGRAMMING ORCHESTRATED BY POLYCOMB-GROUP REPRESSIVE COMPLEXES. THE DATA ARE OF INTEREST IN THE CONTEXT OF EPIGENETIC-BASED THERAPY.	2012	

18  6382  34 THE ROLE OF PARTICULATE MATTERS ON METHYLATION OF IFN-GAMMA AND IL-4 PROMOTER GENES IN PEDIATRIC ALLERGIC RHINITIS. ALLERGIC RHINITIS (AR) IS A CHRONIC INFLAMMATORY DISORDER DRIVEN BY T CELL ACTIVATION. HOW PARTICULATE MATTER CONTRIBUTES TO EPIGENETIC CHANGES THAT IN TURN INFLUENCE CYTOKINE GENE EXPRESSION IN CD4(+)T CELLS REMAINS UNCLEAR. IN THIS STUDY, 105 CHILDREN DIAGNOSED WITH AR AND 90 HEALTHY CONTROLS WERE RECRUITED TO EXPLORE THE POSSIBLE MECHANISM OF PARTICULATE MATTER (PM) ON THE EPIGENETIC REGULATION OF CD4(+)T IFN-GAMMA AND IL-4 PROMOTER GENES. DAILY AVERAGE PM(10) AND PM(2.5) WERE OBTAINED FROM FIVE STATE-CONTROLLED MONITORING STATIONS, AND ACTIVITY-BASED DYNAMIC EXPOSURE AND PERSONAL EXPOSURE DATA WERE COLLECTED. DNA METHYLATION PATTERNS OF IFN-GAMMA AND IL-4 PROMOTER REGIONS WERE ANALYZED USING BISULFITE SEQUENCING. MRNA LEVELS WERE DETECTED BY REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION. WE FOUND THAT THE METHYLATION RATE IN IFN-GAMMA WAS HIGHER IN AR CD4(+)T CELLS THAN IN THE CONTROLS. IFN-GAMMA MRNA EXPRESSION WAS SIGNIFICANTLY DECREASED IN CD4(+)T CELLS, AND NEGATIVELY CORRELATED WITH THE MEAN METHYLATION LEVEL OF IFN-GAMMA. HOWEVER, NO CORRELATION BETWEEN IL-4 METHYLATION AND IL-4 MRNA EXPRESSION WAS FOUND. AFTER ADJUSTING FOR AGE, GENDER, EXCLUSIVE BREASTFEEDING WITHIN 4 MONTHS AFTER BIRTH AND PARENTAL HISTORY OF ALLERGIC DISEASE, OUT DATA SHOWED THAT PM(2.5) EXPOSURE LEVEL WAS POSITIVELY CORRELATED WITH METHYLATION LEVEL IN IFN-GAMMA PROMOTER REGION AND DECREASED CYTOKINE EXPRESSION. WE CONCLUDE THAT THE EFFECT OF PM(2.5) ON PEDIATRIC AR MAY BE MEDIATED THROUGH EPIGENETIC MODIFICATION OF IFN-GAMMA PROMOTER REGION.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
19   507  28 ASSOCIATION OF INCREASED DNA METHYLTRANSFERASE EXPRESSION WITH CARCINOGENESIS AND POOR PROGNOSIS IN PANCREATIC DUCTAL ADENOCARCINOMA. INTRODUCTION: EPIGENETIC MODIFICATIONS PLAY AN IMPORTANT ROLE IN MULTISTAGE CARCINOGENESIS. THE ROLE OF THE THREE FUNCTIONAL DNA METHYLTRANSFERASES (DNMTS) IN PANCREATIC CARCINOGENESIS HAS NOT BEEN FULLY UNDERSTOOD. THE MAIN GOAL OF THIS STUDY WAS TO EXAMINE DNMT EXPRESSION IN DIFFERENT STAGES OF PANCREATIC DUCTAL ADENOCARCINOMA (PDAC), AND EVALUATE THEIR PROGNOSTIC SIGNIFICANCE IN PDAC. MATERIALS AND METHODS: A LARGE NUMBER OF PREMALIGNANT AND MALIGNANT PANCREATIC LESIONS WERE OBTAINED BY MANUAL MICRODISSECTION. QUANTITATIVE REAL-TIME RT-PCR WAS USED TO DETECT DNMTS MRNA EXPRESSION. NONPARAMETRIC TEST, LOGRANK TEST AND COX REGRESSION ANALYSIS WERE USED TO EVALUATE THE CLINICAL SIGNIFICANCE OF DNMT EXPRESSION. RESULTS: THE MRNA EXPRESSION OF THE THREE DNMTS INCREASED WITH THE DEVELOPMENT OF PANCREATIC CANCER FROM NORMAL DUCT TO PANCREATIC INTRADUCTAL NEOPLASIA AND FURTHER TO PDAC, AND WERE STATISTICALLY CORRELATED WITH EACH OTHER. EXPRESSION OF THE THREE DNMTS WAS STATISTICALLY CORRELATED WITH TNM STAGING AND HISTORY OF CHRONIC PANCREATITIS. DNMT3A AND DNMT3B, BUT NOT DNMT1 EXPRESSION, WAS STATISTICALLY CORRELATED WITH TUMOUR SIZE. PATIENTS WITH HIGHER LEVELS OF DNMT1, DNMT3A AND/OR DNMT3B EXPRESSION HAD AN OVERALL LOWER SURVIVAL THAN THOSE WITH LOWER LEVELS OF EXPRESSION. UNIVARIATE ANALYSIS SHOWED THAT HIGH EXPRESSION LEVELS OF DNMTS, ALCOHOL CONSUMPTION, TUMOUR DIFFERENTIATION AND TNM STAGING WERE STATISTICALLY SIGNIFICANT RISK FACTORS. MULTIVARIATE ANALYSIS SHOWED THAT HIGH LEVEL OF DNMT3B EXPRESSION AND TUMOUR DIFFERENTIATION WERE STATISTICALLY SIGNIFICANT INDEPENDENT POOR PROGNOSTIC FACTORS. CONCLUSIONS: THESE RESULTS SUGGESTED THAT PANCREATIC CARCINOGENESIS INVOLVES AN INCREASED MRNA EXPRESSION OF THREE DNMTS, AND THEY MAY BECOME VALUABLE DIAGNOSTIC AND PROGNOSTIC MARKERS AS WELL AS POTENTIAL THERAPEUTIC TARGETS FOR PANCREATIC CANCER.	2012	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
20  4899  29 OXIDATIVE STRESS MEDIATES THE APOPTOSIS AND EPIGENETIC MODIFICATION OF THE BCL-2 PROMOTER VIA DNMT1 IN A CIGARETTE SMOKE-INDUCED EMPHYSEMA MODEL. BACKGROUND: EMPHYSEMA IS A CRUCIAL PATHOLOGICAL CHARACTERISTIC OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). OXIDATIVE STRESS, APOPTOSIS AND EPIGENETIC MECHANISMS CONTRIBUTE TO THE PATHOGENESIS OF EMPHYSEMA. HOWEVER, AN ATTEMPT TO ACCURATELY IDENTIFY WHETHER THESE MECHANISMS INTERACT WITH EACH OTHER AND HOW THEY ARE TRIGGERED HAS NEVER BEEN CONDUCTED. METHOD: THE TOTAL REACTIVE OXYGEN SPECIES (ROS) LEVEL, PULMONARY APOPTOSIS AND B-CELL LYMPHOMA/LEUKEMIA-2 (BCL-2) EXPRESSION, AN APOPTOSIS REGULATOR, WERE DETECTED IN SAMPLES FROM COPD PATIENTS. BISULFITE SEQUENCING PCR (BSP) WAS CONDUCTED TO OBSERVE THE ALTERATIONS IN THE METHYLATION OF THE BCL-2 PROMOTER IN SPECIMENS. THE DYSREGULATION OF DNA METHYLTRANSFERASE ENZYME 1 (DNMT1), A VITAL DNA METHYLTRANSFERASE ENZYME, IN THE LUNGS OF PATIENTS WAS CONFIRMED THROUGH WESTERN BLOTTING. TO FIND OUT INTERACTIONS BETWEEN OXIDATIVE STRESS AND DNA METHYLATION IN EMPHYSEMA, MOUSE MODELS WERE BUILT WITH ANTIOXIDANT TREATMENT AND DNMT1 SILENCING, AND WERE EXAMINED WITH THE PULMONARY APOPTOSIS, BCL-2 AND DNMT1 LEVELS, AND EPIGENETIC ALTERATIONS OF BCL-2. RESULTS: HIGHER ROS LEVELS AND PULMONARY APOPTOSIS WERE OBSERVED IN COPD PATIENTS THAN IN HEALTHY CONTROLS. DOWNREGULATED BCL-2 EXPRESSION WITH INCREASED PROMOTER METHYLATION AND DNMT1 PROTEIN EXPRESSION WAS FOUND IN COPD PATIENTS. ANTIOXIDANT TREATMENT REDUCED THE LEVEL OF ROS, DNMT1 PROTEIN AND EMPHYSEMATOUS PROGRESSION IN THE SMOKING MODELS. FOLLOWING DNMT1 BLOCKADE, SMOKING MODELS SHOWED IMPROVED LUNG FUNCTION, PULMONARY APOPTOSIS, EMPHYSEMATOUS PROGRESSION, AND INCREASED BCL-2 PROTEIN LEVEL WITH LESS PROMOTER METHYLATION THAN EMPHYSEMA MICE. CONCLUSION: CIGARETTE-INDUCED OXIDATIVE STRESS MEDIATES PULMONARY APOPTOSIS AND HYPERMETHYLATION OF THE BCL-2 PROMOTER IN EMPHYSEMA MODELS THROUGH DNMT1.	2020