1 6382 132 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 2 2766 45 EXPRESSION, POLYMORPHISM AND METHYLATION PATTERN OF INTERLEUKIN-6 IN PERIODONTAL TISSUES. PERIODONTITIS IS CONSIDERED AN INFLAMMATORY DISORDER OF BACTERIAL ETIOLOGY THAT RESULTS IN PERIODONTAL TISSUE DESTRUCTION, AS A RESULT OF COMPLEX INTERACTIONS BETWEEN PERIODONTAL PATHOGENS, HOST AND IMMUNE RESPONSE. GENETIC AND EPIGENETIC MECHANISMS MAY MODULATE THE INDIVIDUAL RESPONSE SINCE IT IS ABLE TO INFLUENCE THE GENE EXPRESSION. THE AIM OF THIS STUDY WAS TO EVALUATE THE IMPACT OF -174 G/C POLYMORPHISM AND THE METHYLATION STATUS OF THE PROMOTER REGION OF IL-6 GENE ON THE EXPRESSION OF IL-6 IN GINGIVAL SAMPLES FROM INDIVIDUALS WITH CHRONIC PERIODONTITIS. GINGIVAL BIOPSIES WERE COLLECTED FROM 21 PATIENTS WITH CHRONIC PERIODONTITIS AND 21 CONTROLS. HISTOLOGIC SECTIONS STAINED BY HEMATOXYLIN-EOSIN WERE USED FOR HISTOPATHOLOGICAL EVALUATION. THE IL-6 GENE EXPRESSION WAS ASSESSED BY QUANTITATIVE REAL-TIME PCR. THE POLYMORPHISM IL-6 -174 C/G WAS STUDIED BY POLYMERASE CHAIN REACTION (PCR) AMPLIFICATION AND RESTRICTION ENDONUCLEASE DIGESTION (HSPII). METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION WAS USED TO VERIFY THE DNA METHYLATION PATTERN. THE NUMBER OF INFLAMMATORY CELLS IN TISSUE FRAGMENTS FROM INDIVIDUALS WITH CHRONIC PERIODONTITIS WAS HIGHER THAN IN THE CONTROL GROUP AND THE INFLAMMATORY INFILTRATE WAS PREDOMINANTLY MONONUCLEAR. THE EXPRESSION OF IL-6 WAS HIGHER IN THE GROUP WITH PERIODONTITIS. IN POLYMORPHISM ASSAY, NO STATISTICAL DIFFERENCE IN THE DISTRIBUTION OF GENOTYPES AND ALLELES IN BOTH GROUPS WERE OBSERVED. THE MOST OF SAMPLES WERE PARTIALLY METHYLATED. NO DIFFERENCE WAS OBSERVED IN METHYLATION PATTERN FROM TWO DIFFERENT REGIONS OF THE IL-6 GENE AMONG GROUPS. THE HIGH EXPRESSION OF IL-6 IS AN IMPORTANT FACTOR RELATED TO CHRONIC PERIODONTITIS, BUT WAS NOT ASSOCIATED WITH METHYLATION STATUS OR THE -174 (G/C) GENETIC POLYMORPHISM, SUGGESTING THAT OTHER MECHANISMS ARE INVOLVED IN THIS GENE TRANSCRIPTION REGULATION. 2013 3 1500 50 DNA METHYLATION ANALYSIS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE THAT IS CHARACTERIZED BY ABERRANT CROSS-TALK BETWEEN KERATINOCYTES AND IMMUNE CELLS SUCH AS CD4+ T CELLS, RESULTING IN KERATINOCYTE HYPERPROLIFERATION IN THE EPIDERMIS. DNA METHYLATION, ONE OF SEVERAL EPIGENETIC MECHANISMS, PLAYS AN IMPORTANT ROLE IN GENE EXPRESSION WITHOUT CHANGING THE DNA SEQUENCE. SEVERAL STUDIES HAVE SUGGESTED THE INVOLVEMENT OF EPIGENETIC REGULATION IN SKIN LESIONS FROM PATIENTS WITH PSORIASIS. IN THIS STUDY, WE INVESTIGATED THE GENOME-WIDE DNA METHYLATION STATUS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS COMPARED WITH HEALTHY SUBJECTS USING METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING (MEDIP-SEQ). THE RESULTS OF MEDIP-SEQ SHOWED THAT THE GLOBAL METHYLATION VALUES OF CD4+ T CELLS ARE HIGHER IN PATIENTS WITH PSORIASIS THAN IN HEALTHY CONTROLS, PARTICULARLY IN THE PROMOTER REGIONS. AMONG THE MOST HYPERMETHYLATED GENES IN THE PROMOTER REGIONS, WE SELECTED THE GENES WHOSE EXPRESSION IS SIGNIFICANTLY REDUCED IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. STUDIES USING THE METHYLATION INHIBITOR 5-AZACYTIDINE IN VITRO METHYLATION ASSAYS HAVE SHOWN THAT THE DIFFERENTIAL EXPRESSION LEVELS WERE ASSOCIATED WITH THE METHYLATION STATUS OF EACH GENE. BISULFITE SEQUENCING OF THE TRANSCRIPTION START REGION OF PHOSPHATIDIC ACID PHOSPHATASE TYPE 2 DOMAIN CONTAINING 3 (PPAPDC3), ONE OF THE SELECTED GENES, SHOWED HYPERMETHYLATION IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. THESE RESULTS SUGGESTED THAT THE METHYLATION STATUS, WHICH IS IDENTIFIED BY MEDIP-SEQ OF THE GENES, WAS CORRELATED WITH THE MRNA EXPRESSION LEVEL OF THE GENES. COLLECTIVELY, THE DNA METHYLATION STATUS IN CD4+ T CELLS MIGHT BE ASSOCIATED WITH THE PATHOGENESIS OF PSORIASIS. 2014 4 1566 41 DNA METHYLATION OF TH1/TH2 CYTOKINE GENES AFFECTS SENSITIZATION AND PROGRESS OF EXPERIMENTAL ASTHMA. BACKGROUND: EPIGENETIC CHANGES IN DNA METHYLATION HAVE RECENTLY BEEN DEMONSTRATED TO BE INVOLVED IN EFFECTOR T-CELL POLARIZATION, RESULTING IN DIFFERENTIAL SECRETION OF T(H)1 AND T(H)2 CYTOKINES. HOWEVER, THE CONTRIBUTION TO THE DEVELOPMENT OF A CHRONIC INFLAMMATORY PHENOTYPE REMAINS STILL UNCLEAR. OBJECTIVE: WE SOUGHT TO INVESTIGATE CHANGES IN DNA METHYLATION IN MARKER GENES OF T-CELL SUBSETS DURING ALLERGEN SENSITIZATION/CHALLENGE AND THEIR INFLUENCE ON THE DEVELOPMENT OF AN ALLERGIC AIRWAY INFLAMMATORY RESPONSE. METHODS: THE RELATIONSHIP BETWEEN CHANGES IN DNA METHYLATION AND PHENOTYPE DEVELOPMENT WERE EXAMINED IN A WELL-ESTABLISHED MODEL OF EXPERIMENTAL ASTHMA. DNA METHYLATION WAS INVESTIGATED AT GENOMIC LOCI ASSOCIATED WITH T(H)1 (IFNG PROMOTER) OR T(H)2 (CONSERVED NONCODING SEQUENCE 1 [CNS1]) CYTOKINE PRODUCTION BY USING BISULFITE PYROSEQUENCING. RESULTS: ANALYSIS OF CD4(+) T CELLS REVEALED A SIGNIFICANT INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER AFTER ALLERGEN SENSITIZATION/CHALLENGE, WHICH CORRELATED WITH DECREASED IFN-GAMMA CYTOKINE EXPRESSION, WHEREAS ONLY MINOR CHANGES WERE OBSERVED AT THE CNS1 LOCUS. FURTHERMORE, THE INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER COULD BE REVERSED WITH A DNA METHYLTRANSFERASE (DNMT) INHIBITOR IN VITRO AND IN VIVO WITH BENEFICIAL EFFECTS ON SENSITIZATION STATUS AND ALLERGIC PHENOTYPE. THE SPECIFIC IMPORTANCE OF THE DNA METHYLATION STATUS IN CD4(+) T CELLS COULD BE CONFIRMED BY USING ADOPTIVE TRANSFER EXPERIMENTS. CONCLUSION: WE HERE REPORT THE NOVEL FINDING THAT EPIGENETIC REGULATION IN T CELLS CONTRIBUTES TO THE DEVELOPMENT OF EXPERIMENTAL ASTHMA AND CAN BE TARGETED PHARMACOLOGICALLY. 2012 5 3440 42 HYPERMETHYLATION AND LOW TRANSCRIPTION OF TLR2 GENE IN CHRONIC PERIODONTITIS. PERIODONTITIS IS AN INFLAMMATORY DISORDER CHARACTERIZED BY INTERACTIONS BETWEEN PERIODONTAL PATHOGENS AND HOST'S IMMUNE RESPONSE. EPIGENETIC MAY CONTRIBUTE TO DISEASE DEVELOPMENT AND OUTCOME BY INFLUENCING THE EXPRESSION OF GENES INVOLVED IN THE IMMUNE RESPONSE. IT HAS BEEN SHOWN THAT TOLL-LIKE RECEPTORS (TLR) PLAY AN IMPORTANT ROLE IN THE RESPONSE TO PERIODONTOPATHIC BACTERIA. THE AIM OF STUDY WAS TO EVALUATE THE METHYLATION STATUS AND THE EXPRESSION OF TLR2 GENE IN GINGIVAL SAMPLES FROM INDIVIDUALS WITH AND WITHOUT PERIODONTITIS. DNA WAS ANALYZED USING THE METHYL PROFILER DNA METHYLATION QPCR ASSAY. DNA METHYLATION AND TRANSCRIPT LEVELS WERE EVALUATED BY REAL-TIME POLYMERASE CHAIN REACTION. THE PERIODONTITIS GROUP SHOWED A HYPERMETHYLATED PROFILE AND A LOW EXPRESSION OF GENE. POSITIVE CORRELATION BETWEEN THE TLR2 METHYLATION FREQUENCY AND PROBING DEPTH WAS OBSERVED. THIS STUDY GIVES THE FIRST EVIDENCE OF METHYLATION FREQUENCY IN INFLAMED PERIODONTAL TISSUES AND OF THE POSSIBLE PARTICIPATION OF METHYLATION IN THE DEVELOPMENT OF PERIODONTITIS. 2013 6 2400 42 EPIGENETIC REPROGRAMMING OF IMMUNE CELLS IN WOMEN WITH PCOS IMPACT GENES CONTROLLING REPRODUCTIVE FUNCTION. CONTEXT: POLYCYSTIC OVARY SYNDROME (PCOS) IS A CHRONIC DISEASE AFFECTING REPRODUCTIVE FUNCTION AND WHOLE-BODY METABOLISM. ALTHOUGH THE ETIOLOGY IS UNCLEAR, EMERGING EVIDENCE INDICATES THAT THE EPIGENETICS MAY BE A CONTRIBUTING FACTOR. OBJECTIVE: TO DETERMINE THE ROLE OF GLOBAL AND GENOME-WIDE EPIGENETIC MODIFICATIONS IN SPECIFIC IMMUNE CELLS IN PCOS COMPARED WITH CONTROLS AND WHETHER THESE COULD BE RELATED TO CLINICAL FEATURES OF PCOS. DESIGN: CROSS-SECTIONAL STUDY. PARTICIPANTS: WOMEN WITH (N = 17) OR WITHOUT PCOS (N = 17). SETTING: RECRUITED FROM THE GENERAL COMMUNITY. MAIN OUTCOME MEASURES: ISOLATED PERIPHERAL BLOOD MONONUCLEAR CELLS WERE ANALYZED USING MULTICOLOR FLOW CYTOMETRY METHODS TO DETERMINE GLOBAL DNA METHYLATION LEVELS IN A CELL-SPECIFIC FASHION. TRANSCRIPTOMIC AND GENOME-WIDE DNA METHYLATION ANALYSES WERE PERFORMED ON T HELPER CELLS USING RNA SEQUENCING AND REDUCED REPRESENTATION BISULFITE SEQUENCING. RESULTS: WOMEN WITH PCOS HAD LOWER GLOBAL DNA METHYLATION IN MONOCYTES (P = 0.006) AND IN T HELPER (P = 0.004), T CYTOTOXIC (P = 0.004), AND B CELLS (P = 0.03). SPECIFIC GENOME-WIDE DNA METHYLATION ANALYSIS OF T HELPER CELLS FROM WOMEN WITH PCOS IDENTIFIED 5581 DIFFERENTIALLY METHYLATED CPG SITES. FUNCTIONAL GENE ONTOLOGY ENRICHMENT ANALYSIS SHOWED THAT GENES LOCATED AT THE PROXIMITY OF DIFFERENTIALLY METHYLATED CPG SITES BELONG TO PATHWAYS RELATED TO REPRODUCTIVE FUNCTION AND IMMUNE CELL FUNCTION. HOWEVER, THESE GENES WERE NOT ALTERED AT THE TRANSCRIPTOMIC LEVEL. CONCLUSIONS: IT WAS SHOWN THAT PCOS IS ASSOCIATED WITH GLOBAL AND GENE-SPECIFIC DNA METHYLATION REMODELING IN A CELL TYPE-SPECIFIC MANNER. FURTHER INVESTIGATION IS WARRANTED TO DETERMINE WHETHER EPIGENETIC REPROGRAMMING OF IMMUNE CELLS IS IMPORTANT IN DETERMINING THE DIFFERENT PHENOTYPES OF PCOS. 2019 7 2281 38 EPIGENETIC REGULATION IN EARLY CHILDHOOD: A MINIATURIZED AND VALIDATED METHOD TO ASSESS HISTONE ACETYLATION. INTRODUCTION: CHRONIC INFLAMMATORY DISEASES INCLUDING ALLERGIES AND ASTHMA ARE THE RESULT OF COMPLEX INTERACTIONS BETWEEN GENES AND ENVIRONMENTAL FACTORS. EPIGENETIC MECHANISMS COMPRISE A SET OF BIOCHEMICAL REACTIONS THAT REGULATE GENE EXPRESSION. IN ORDER TO UNDERSTAND THE CAUSE-EFFECT RELATIONSHIP BETWEEN ENVIRONMENTAL EXPOSURES AND DISEASE DEVELOPMENT, METHODS CAPABLE OF ASSESSING EPIGENETIC REGULATION (ALSO) IN LARGE COHORTS ARE NEEDED. METHODS: FOR THIS PURPOSE, WE DEVELOPED AND EVALUATED A MINIATURIZED CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY ALLOWING FOR A COST-EFFECTIVE ASSESSMENT OF HISTONE ACETYLATION OF CANDIDATE GENES IN A QUANTITATIVE FASHION. THIS METHOD WAS THEN APPLIED TO ASSESS H3 AND H4 HISTONE ACETYLATION CHANGES IN CORD BLOOD (CB) SAMPLES FROM AN ESTABLISHED COHORT OF AUSTRALIAN CHILDREN EXPOSED IN THE FETAL PERIOD TO EITHER VERY LOW OR VERY HIGH LEVELS OF MATERNAL FOLATE. RESULTS: OUR CHIP ASSAY WAS VALIDATED FOR A MINIMUM REQUIREMENT OF 1 X 105 TARGET CELLS (E.G. CD4+ T CELLS). VERY HIGH LEVELS OF MATERNAL FOLATE WERE SIGNIFICANTLY ASSOCIATED WITH INCREASED H3/H4 ACETYLATION AT GATA3 AND/OR IL9 PROMOTER REGIONS IN CD4+ T CELLS IN CB. CONCLUSION: WE DEVELOPED A CHIP METHOD ALLOWING RELIABLE ASSESSMENT OF H3/H4 ACETYLATION USING 1 X 105 CELLS ONLY. PRACTICAL APPLICATION OF THIS ASSAY DEMONSTRATED AN ASSOCIATION BETWEEN HIGH MATERNAL FOLATE EXPOSURE AND INCREASED HISTONE ACETYLATION, CORRESPONDING TO A MORE TRANSCRIPTIONALLY PERMISSIVE CHROMATIN STATUS IN THE PROMOTER REGIONS OF SOME TH2-RELATED GENES. 2015 8 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 9 6311 37 THE RELATION BETWEEN DNA METHYLATION PATTERNS AND SERUM CYTOKINE LEVELS IN COMMUNITY-DWELLING ADULTS: A PRELIMINARY STUDY. BACKGROUND: THE LEVELS OF CIRCULATING CYTOKINES FLUCTUATE WITH AGE, ACUTE ILLNESS, AND CHRONIC DISEASE, AND ARE PREDICTIVE OF MORTALITY; THIS IS ALSO TRUE FOR PATTERNS OF DNA (CPG) METHYLATION. GIVEN THAT IMMUNE CELLS ARE PARTICULARLY SENSITIVE TO CHANGES IN THE CONCENTRATION OF CYTOKINES IN THEIR MICROENVIRONMENT, WE HYPOTHESIZED THAT SERUM LEVELS OF TNF, IL-6, IL-8 AND IL-10 WOULD CORRELATE WITH GENOME-WIDE ALTERATIONS IN THE DNA METHYLATION LEVELS OF BLOOD LEUKOCYTES. TO TEST THIS, WE EVALUATED COMMUNITY-DWELLING ADULTS (N = 14; 48-78 YEARS OLD) RECRUITED TO A PILOT STUDY FOR THE CANADIAN LONGITUDINAL STUDY ON AGING (CLSA), EXAMINING DNA METHYLATION PATTERNS IN PERIPHERAL BLOOD MONONUCLEAR CELLS USING THE ILLUMINA HUMANMETHYLATION 450 K BEADCHIP. RESULTS: WE SHOW THAT, APART FROM AGE, SERUM IL-10 LEVELS EXHIBITED THE MOST SUBSTANTIAL ASSOCIATION TO DNA METHYLATION PATTERNS, FOLLOWED BY TNF, IL-6 AND IL-8. FURTHERMORE, WHILE THE LEVELS OF THESE CYTOKINES WERE HIGHER IN ELDERLY ADULTS, NO ASSOCIATIONS WITH EPIGENETIC ACCELERATED AGING, DERIVED USING THE EPIGENETIC CLOCK, WERE OBSERVED. CONCLUSIONS: AS A PRELIMINARY STUDY WITH A SMALL SAMPLE SIZE, THE CONCLUSIONS DRAWN FROM THIS WORK MUST BE VIEWED WITH CAUTION; HOWEVER, OUR OBSERVATIONS ARE ENCOURAGING AND CERTAINLY WARRANT MORE SUITABLY POWERED STUDIES OF THIS RELATIONSHIP. 2017 10 1589 40 DNA METHYLATION PROFILING IN A CIGARETTE SMOKE-EXPOSED MOUSE MODEL OF AIRWAY INFLAMMATION. PURPOSE: DNA METHYLATION, A MAJOR EPIGENETIC MODIFICATION, HAS BEEN DOCUMENTED TO PLAY AN IMPORTANT ROLE IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). IN THIS STUDY, WE AIMED TO PROFILE THE DNA METHYLATION PATTERNS IN A MOUSE MODEL OF AIRWAY INFLAMMATION INDUCED BY CIGARETTE SMOKE (CS), A FOREMOST RISK FACTOR OF COPD. MATERIAL AND METHODS: TO ESTABLISH A MODEL OF AIRWAY INFLAMMATION, WILD-TYPE MICE WERE EXPOSED TO MAINSTREAM CS OR ROOM AIR FOR 2 HOURS TWICE DAILY, 6 DAYS PER WEEK FOR CONSECUTIVE 4 WEEKS. LUNG TISSUES OF THE MICE WERE COLLECTED FOR GENOME-WIDE DNA METHYLATION ANALYSIS BY LIQUID HYBRIDIZATION CAPTURE-BASED BISULFITE SEQUENCING, WHICH WERE USED FOR INTERSECTION ANALYSIS WITH GENE EXPRESSION BY CDNA MICROARRAY TO IDENTIFY CANDIDATE METHYLATED GENES. THEN, FUNCTIONAL ENRICHMENT ANALYSES WITH PROTEIN-PROTEIN INTERACTION (PPI) NETWORK REGARDING THESE GENES WERE CONDUCTED TO EXPLORE THE POTENTIAL MECHANISMS. RESULTS: AFTER 4-WEEK CS EXPOSURE, THE LEVEL OF DNA METHYLATION ACCOMPANIED BY A SUBACUTE AIRWAY INFLAMMATION WAS MARKEDLY ENHANCED, AND 2002 DIFFERENTIALLY METHYLATED GENES (DMGS) WERE ANNOTATED, INCLUDING 565 DMGS CONTAINED METHYLATIONS IN GENE PROMOTERS, WHICH WERE USED FOR INTERSECTION WITH THE DIFFERENTIALLY EXPRESSED GENES. THEN, 135 CANDIDATE METHYLATED GENES WERE FURTHER SELECTED BY THE INTERSECTION, AMONG WHICH 58 GENES WITH FUNCTIONAL METHYLATED MODIFICATION WERE FINALLY IDENTIFIED. FURTHER ANALYSES REVEALED CANDIDATE METHYLATED GENES WERE SIGNIFICANTLY ENRICHED IN A COMPLICATED NETWORK OF SIGNALS AND PROCESSES, INCLUDING INTERLEUKINS, TOLL-LIKE RECEPTORS, T-CELLS DIFFERENTIATION, OXIDATIVE STRESS, MAST CELLS ACTIVATION, STEM CELLS PROLIFERATION, ETC., AS WELL AS THE 58 FUNCTIONAL METHYLATED GENES WERE PARTIALLY LOCATED AT KEY POSITIONS IN PPI NETWORK, ESPECIALLY CXCL1, DDX58 AND JAK3. CONCLUSION: THIS STUDY SUGGESTS CS EXPOSURE SIGNIFICANTLY ENHANCES DNA METHYLATED LEVEL, AND THE POTENTIAL FUNCTIONAL METHYLATED GENES ARE CLOSELY RELATED TO COMPLICATED INFLAMMATORY-IMMUNE RESPONSES, WHICH MAY PROVIDE SOME NEW EXPERIMENTAL EVIDENCE IN UNDERSTANDING THE EPIGENETIC MECHANISMS OF CS-INDUCED AIRWAY INFLAMMATION IN COPD. 2022 11 344 46 ALTERED BDNF METHYLATION IN PATIENTS WITH CHRONIC MUSCULOSKELETAL PAIN AND HIGH BIOPSYCHOSOCIAL COMPLEXITY. PURPOSE: THE INTERMED INSTRUMENT, WHICH WAS DEVELOPED TO MEASURE PATIENT'S BIOPSYCHOSOCIAL (BPS) COMPLEXITY, REPRESENTS A POWERFUL DIAGNOSTIC AND THERAPEUTIC TOOL. EPIGENETIC CHANGES ARE THE INTERFACE BETWEEN SIGNALS FROM THE ENVIRONMENT AND GENETIC MODIFICATIONS, AFFECTING GENE EXPRESSION, IN PARTICULAR, BY DNA METHYLATION OF CPG DINUCLEOTIDES IN PROMOTOR REGIONS OF THE CORRESPONDING GENES. THE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) GENE PLAYS A CRUCIAL ROLE IN THE CENTRAL SENSITIZATION (CS) OF PAIN. IN THIS STUDY, WE HYPOTHESIZED THAT CHRONIC PAIN MODIFIES THE METHYLATION LEVELS OF THE BDNF GENE IN A MANNER THAT IS INTERCONNECTED WITH THE BPS STATUS. PATIENTS AND METHODS: FIFTY-EIGHT CHRONIC MUSCULOSKELETAL PAIN PATIENTS (CMSP) WERE ENROLLED IN THE STUDY. DNA WAS EXTRACTED FROM BLOOD SAMPLES, THE METHYLATION LEVELS OF 13 CPG SITES IN THE BDNF PROMOTER WERE MEASURED BY PYROSEQUENCING, AND ASSOCIATION STUDIES WITH VARIOUS PATIENT PARAMETERS AND THE INTERMED SCORES WERE PERFORMED. RESULTS: INTERESTINGLY, A NEGATIVE CORRELATION (-0.40) WAS FOUND BETWEEN THE TOTAL INTERMED SCORES AND THE AVERAGE CPG METHYLATION VALUES OF THE BDNF GENE, BUT NO CORRELATION WAS OBSERVED WITH THE SEVERITY OF PAIN, DEGREE OF ANXIETY, DEPRESSION, OR KINESIOPHOBIA AND CATASTROPHISM. MOREOVER, THE ASSOCIATION WAS INDEPENDENT OF AGE, SEX AND LEVEL OF COMORBIDITIES. CONCLUSION: THIS RESULT SHOWS THAT CMSP, IN ASSOCIATION WITH ITS BIOPSYCHOSOCIAL CONTEXT, EPIGENETICALLY DECREASES THE DEGREE OF METHYLATION OF THE BDNF PROMOTER AND SHOULD THEREFORE INCREASE THE LEVEL OF BDNF TRANSCRIPTION. IT ALSO SUGGESTS A ROLE OF THE INTERMED TOOL TO DETECT A RELATIONSHIP BETWEEN THE BPS COMPLEXITY AND THE EPIGENETIC CONTROL OF A TARGET GENE. THE POSSIBLE UPREGULATION OF BDNF EXPRESSION MIGHT BE, AT LEAST IN PART, THE SIGNAL FOR CHRONIC PAIN-INDUCED CENTRAL SENSITIZATION (CS). THIS COULD PARTLY EXPLAIN WHY PATIENTS WITH A HIGHER LEVEL OF COMPLEXITY FEEL MORE PAIN THAN THOSE WITH LOWER COMPLEXITY. 2020 12 1967 45 EPIGENETIC ALTERATION OF THE DOPAMINE TRANSPORTER GENE IN ALCOHOL-DEPENDENT PATIENTS IS ASSOCIATED WITH AGE. CHRONIC ALCOHOL ABUSE AND DEPENDENCE ARE ASSOCIATED WITH DYSFUNCTIONAL DOPAMINERGIC NEUROTRANSMISSION IN MESOCORTICOLIMBIC CIRCUITS. GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN SHOWN TO MODULATE SUSCEPTIBILITY TO ALCOHOL DEPENDENCE, AND BOTH MAY ACT THROUGH EPIGENETIC MECHANISMS THAT CAN MODULATE GENE EXPRESSION, E.G. DNA METHYLATION AT CPG SITES. RECENT STUDIES HAVE SUGGESTED THAT DNA METHYLATION PATTERNS MAY CHANGE OVER TIME. HOWEVER, FEW DATA ARE AVAILABLE CONCERNING THE RATE OF THESE CHANGES IN SPECIFIC GENES. A RECENT STUDY FOUND THAT HYPERMETHYLATION OF THE PROMOTER OF THE DOPAMINE TRANSPORTER (DAT) GENE WAS POSITIVELY CORRELATED WITH ALCOHOL DEPENDENCE AND NEGATIVELY CORRELATED WITH ALCOHOL CRAVING. THE AIM OF THE PRESENT STUDY WAS TO REPLICATE THESE FINDINGS IN A LARGER SAMPLE OF ALCOHOL-DEPENDENT PATIENTS AND POPULATION-BASED CONTROLS MATCHED FOR AGE AND SEX. NO DIFFERENCE IN METHYLATION LEVEL WAS OBSERVED BETWEEN PATIENTS AND CONTROLS, AND NO DIFFERENCE IN METHYLATION LEVEL WAS OBSERVED BEFORE AND AFTER ALCOHOL WITHDRAWAL IN PATIENTS. HOWEVER, PATIENTS WITH MORE SEVERE CRAVING SHOWED A TREND TOWARDS LOWER DAT METHYLATION LEVELS (P = 0.07), WHICH IS CONSISTENT WITH PREVIOUS FINDINGS. FURTHERMORE, IN OUR OVERALL SAMPLE, DAT METHYLATION LEVELS INCREASED WITH AGE. INTERESTINGLY, A SEPARATE ANALYSIS OF PATIENTS SUGGESTED THAT THIS FINDING WAS MAINLY DRIVEN BY THE PATIENT GROUP. ALTHOUGH THE PRESENT DATA DO NOT CLARIFY WHETHER CHRONIC ALCOHOL ABUSE IS RESPONSIBLE FOR THIS PHENOMENON OR MERELY ENHANCES AN AGEING-SPECIFIC PROCESS, OUR FINDINGS SUGGEST THAT HYPERMETHYLATION IN ALCOHOL-DEPENDENT PATIENTS IS A CONSEQUENCE, RATHER THAN A CAUSE, OF THE DISORDER. 2014 13 2771 43 EXTENSIVE PROMOTER DNA HYPERMETHYLATION AND HYPOMETHYLATION IS ASSOCIATED WITH ABERRANT MICRORNA EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA. DYSREGULATED MICRORNA (MIRNA) EXPRESSION CONTRIBUTES TO THE PATHOGENESIS OF HEMATOPOIETIC MALIGNANCIES, INCLUDING CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). HOWEVER, AN UNDERSTANDING OF THE MECHANISMS THAT CAUSE ABERRANT MIRNA TRANSCRIPTIONAL CONTROL IS LACKING. IN THIS STUDY, WE COMPREHENSIVELY INVESTIGATED THE ROLE AND EXTENT OF MIRNA EPIGENETIC REGULATION IN CLL. GENOME-WIDE PROFILING CONDUCTED ON 24 CLL AND 10 HEALTHY B CELL SAMPLES REVEALED GLOBAL DNA METHYLATION PATTERNS UPSTREAM OF MIRNA SEQUENCES THAT DISTINGUISHED MALIGNANT FROM HEALTHY CELLS AND IDENTIFIED PUTATIVE MIRNA PROMOTERS. INTEGRATION OF DNA METHYLATION AND MIRNA PROMOTER DATA LED TO THE IDENTIFICATION OF 128 RECURRENT MIRNA TARGETS FOR ABERRANT PROMOTER DNA METHYLATION. DNA HYPOMETHYLATION ACCOUNTED FOR MORE THAN 60% OF ALL ABERRANT PROMOTER-ASSOCIATED DNA METHYLATION IN CLL, AND PROMOTER DNA HYPOMETHYLATION WAS RESTRICTED TO WELL-DEFINED REGIONS. INDIVIDUAL HYPER- AND HYPOMETHYLATED PROMOTERS ALLOWED DISCRIMINATION OF CLL SAMPLES FROM HEALTHY CONTROLS. PROMOTER DNA METHYLATION PATTERNS WERE CONFIRMED IN AN INDEPENDENT PATIENT COHORT, WITH 11 MIRNAS CONSISTENTLY SHOWING AN INVERSE CORRELATION BETWEEN DNA METHYLATION STATUS AND EXPRESSION LEVEL. TOGETHER, OUR FINDINGS CHARACTERIZE THE ROLE OF EPIGENETIC CHANGES IN THE REGULATION OF MIRNA TRANSCRIPTION AND CREATE A REPOSITORY OF DISEASE-SPECIFIC PROMOTER REGIONS THAT MAY PROVIDE ADDITIONAL INSIGHTS INTO THE PATHOGENESIS OF CLL. 2012 14 3981 31 LONG-TERM EPIGENETIC THERAPY WITH ORAL ZEBULARINE HAS MINIMAL SIDE EFFECTS AND PREVENTS INTESTINAL TUMORS IN MICE. RECENT SUCCESSES IN THE APPLICATION OF EPIGENETIC DRUGS FOR THE TREATMENT OF MYELODYSPLASTIC SYNDROME HAVE RAISED QUESTIONS ON THE SAFETY OF LONG-TERM ADMINISTRATION OF DNA METHYLATION INHIBITORS. WE TREATED PREWEANED CANCER PRONE APC(MIN/+) (MIN) MICE CONTINUOUSLY WITH THE DNA METHYLATION INHIBITOR ZEBULARINE IN THEIR DRINKING WATER TO DETERMINE THE EFFECTS OF THE DRUG ON NORMAL MOUSE DEVELOPMENT AS WELL AS CANCER PREVENTION. ZEBULARINE CAUSED A TISSUE-SPECIFIC REDUCTION IN DNA METHYLATION AT B1 SHORT INTERSPERSED NUCLEOTIDE ELEMENTS IN THE SMALL AND LARGE INTESTINES OF FEMALE MIN MICE BUT NOT IN OTHER ORGANS EXAMINED AFTER CHRONIC ORAL TREATMENT. NO SIGNIFICANT DIFFERENCE IN THE AVERAGE WEIGHTS OF MICE WAS OBSERVED DURING THE TREATMENT. IN ADDITION, ANALYSIS OF GLOBAL GENE EXPRESSION OF COLONIC EPITHELIAL CELLS FROM THE FEMALES INDICATED THAT ONLY 3% TO 6% OF THE GENES WERE AFFECTED IN THEIR EXPRESSION. WE DID NOT DETECT TOXICITY AND ABNORMALITIES FROM THE HISTOPATHOLOGIC ANALYSIS OF LIVER AND INTESTINAL TISSUES. LASTLY, WE TESTED WHETHER PREVENTION OF TUMORIGENESIS CAN BE ACHIEVED WITH CHRONIC ORAL ADMINISTRATION OF ZEBULARINE IN MIN MICE. THE AVERAGE NUMBER OF POLYPS IN MIN FEMALES DECREASED FROM 58 TO 1, WHEREAS THE AVERAGE POLYP NUMBER REMAINED UNAFFECTED IN MIN MALES POSSIBLY DUE TO DIFFERENTIAL ACTIVITY OF ALDEHYDE OXIDASE. TAKEN TOGETHER, OUR RESULTS SHOW FOR THE FIRST TIME THAT LONG-TERM ORAL ADMINISTRATION OF ZEBULARINE CAUSES A GENDER-SPECIFIC ABROGATION OF INTESTINAL TUMORS WHILE CAUSING A TISSUE-SPECIFIC DNA DEMETHYLATION. IMPORTANTLY, PROLONGED TREATMENT OF MICE WITH EPIGENETIC DRUGS RESULTED IN ONLY MINOR DEVELOPMENTAL AND HISTOLOGIC CHANGES. 2008 15 4879 24 OVERLAPPING SIGNATURES OF CHRONIC PAIN IN THE DNA METHYLATION LANDSCAPE OF PREFRONTAL CORTEX AND PERIPHERAL T CELLS. WE TESTED THE HYPOTHESIS THAT EPIGENETIC MECHANISMS IN THE BRAIN AND THE IMMUNE SYSTEM ARE ASSOCIATED WITH CHRONIC PAIN. GENOME-WIDE DNA METHYLATION ASSESSED IN 9 MONTHS POST NERVE-INJURY (SNI) AND SHAM RATS, IN THE PREFRONTAL CORTEX (PFC) AS WELL AS IN T CELLS REVEALED A VAST DIFFERENCE IN THE DNA METHYLATION LANDSCAPE IN THE BRAIN BETWEEN THE GROUPS AND A REMARKABLE OVERLAP (72%) BETWEEN DIFFERENTIALLY METHYLATED PROBES IN T CELLS AND PREFRONTAL CORTEX. DNA METHYLATION STATES IN THE PFC SHOWED ROBUST CORRELATION WITH PAIN SCORE OF ANIMALS IN SEVERAL GENES INVOLVED IN PAIN. FINALLY, ONLY 11 DIFFERENTIALLY METHYLATED PROBES IN T CELLS WERE SUFFICIENT TO DISTINGUISH SNI OR SHAM INDIVIDUAL RATS. THIS STUDY SUPPORTS THE PLAUSIBILITY OF DNA METHYLATION INVOLVEMENT IN CHRONIC PAIN AND DEMONSTRATES THE POTENTIAL FEASIBILITY OF DNA METHYLATION MARKERS IN T CELLS AS NONINVASIVE BIOMARKERS OF CHRONIC PAIN SUSCEPTIBILITY. 2016 16 1215 44 CPG PROMOTER METHYLATION STATUS IS NOT A PROGNOSTIC INDICATOR OF GENE EXPRESSION IN BERYLLIUM CHALLENGE. INDIVIDUALS EXPOSED TO BERYLLIUM (BE) MAY DEVELOP BE SENSITIZATION (BES) AND PROGRESS TO CHRONIC BERYLLIUM DISEASE (CBD). RECENT STUDIES WITH OTHER METAL ANTIGENS SUGGEST EPIGENETIC MECHANISMS MAY BE INVOLVED IN INFLAMMATORY DISEASE PROCESSES, INCLUDING GRANULOMATOUS LUNG DISORDERS AND THAT A NUMBER OF METAL CATIONS ALTER GENE METHYLATION. THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE IF BE CAN EXERT AN EPIGENETIC EFFECT ON GENE EXPRESSION BY ALTERING METHYLATION IN THE PROMOTER REGION OF SPECIFIC GENES KNOWN TO BE INVOLVED IN BE ANTIGEN-MEDIATED GENE EXPRESSION. TO INVESTIGATE THIS OBJECTIVE, THREE MACROPHAGE TUMOR MOUSE CELL LINES KNOWN TO DIFFERENTIALLY PRODUCE TUMOR NECROSIS FACTOR (TNF)-ALPHA, BUT NOT INTERFERON (IFN)-GAMMA, IN RESPONSE TO BE ANTIGEN WERE CULTURED WITH BE OR CONTROLS. FOLLOWING CHALLENGES, ELISA WERE PERFORMED TO QUANTIFY INDUCED TNFALPHA AND IFNGAMMA EXPRESSION. BISULFATE-CONVERTED DNA WAS EVALUATED BY PYROSEQUENCING TO QUANTIFY CPG METHYLATION WITHIN THE PROMOTERS OF TNFALPHA AND IFNGAMMA. BE-CHALLENGED H36.12J CELLS EXPRESSED HIGHER LEVELS OF TNFALPHA COMPARED TO EITHER H36.12E CELLS OR P388D.1 CELLS. HOWEVER, THERE WERE NO VARIATIONS IN TNFALPHA PROMOTER CPG METHYLATION LEVELS BETWEEN CELL LINES AT THE SIX CPG SITES TESTED. H36.12J CELL TNFALPHA EXPRESSION WAS SHOWN TO BE METAL-SPECIFIC BY THE INDUCTION OF SIGNIFICANTLY MORE TNFALPHA WHEN EXPOSED TO BE THAN WHEN EXPOSED TO ALUMINUM SULFATE, OR NICKEL (II) CHLORIDE, BUT NOT WHEN EXPOSED TO COBALT (II) CHLORIDE. HOWEVER, H36.12J CELL METHYLATION LEVELS AT THE SIX CPG SITES EXAMINED IN THE TNFALPHA PROMOTER DID NOT CORRELATE WITH CYTOKINE EXPRESSION DIFFERENCES. NONETHELESS, ALL THREE CELL LINES HAD SIGNIFICANTLY MORE PROMOTER METHYLATION AT THE SIX CPG SITES INVESTIGATED WITHIN THE IFNGAMMA PROMOTER (A GENE THAT IS NOT EXPRESSED) WHEN COMPARED TO THE SIX CPG SITES INVESTIGATED IN THE TNFALPHA PROMOTER, REGARDLESS OF TREATMENT CONDITION (P < 1.17 X 10(-9)). THESE FINDINGS SUGGEST THAT, IN THIS CELL SYSTEM, PROMOTER HYPO-METHYLATION MAY BE NECESSARY TO ALLOW EXPRESSION OF METAL-INDUCED TNFALPHA AND THAT PROMOTER HYPER-METHYLATION IN THE IFNGAMMA PROMOTER MAY INTERFERE WITH EXPRESSION. ALSO, AT THE DOZEN CPG SITES INVESTIGATED IN THE PROMOTER REGIONS OF BOTH GENES, BERYLLIUM HAD NO IMPACT ON PROMOTER METHYLATION STATUS, DESPITE ITS ABILITY TO INDUCE PRO-INFLAMMATORY CYTOKINE EXPRESSION. 2016 17 5034 32 PHARMACOEPIGENETICS OF THE ROLE OF DNA METHYLATION IN MU-OPIOID RECEPTOR EXPRESSION IN DIFFERENT HUMAN BRAIN REGIONS. AIM: EXPOSURE TO OPIOIDS HAS BEEN ASSOCIATED WITH EPIGENETIC EFFECTS. STUDIES IN RODENTS SUGGESTED A ROLE OF VARYING DEGREES OF DNA METHYLATION IN THE DIFFERENTIAL REGULATION OF MU-OPIOID RECEPTOR EXPRESSION ACROSS THE BRAIN. METHODS: IN A TRANSLATIONAL INVESTIGATION, USING TISSUE ACQUIRED POSTMORTEM FROM 21 BRAIN REGIONS OF FORMER OPIATE ADDICTS, REPRESENTING A HUMAN COHORT WITH CHRONIC OPIOID EXPOSURE, MU-OPIOID RECEPTOR EXPRESSION WAS ANALYZED AT THE LEVEL OF DNA METHYLATION, MRNA AND PROTEIN. RESULTS & CONCLUSION: WHILE HIGH OR LOW MU-OPIOID RECEPTOR EXPRESSION SIGNIFICANTLY CORRELATED WITH LOCAL OPRM1 MRNA LEVELS, THERE WAS NO CORRESPONDING ASSOCIATION WITH OPRM1 METHYLATION STATUS. ADDITIONAL EXPERIMENTS IN HUMAN CELL LINES SHOWED THAT CHANGES IN DNA METHYLATION ASSOCIATED WITH CHANGES IN MU-OPIOID EXPRESSION WERE AN ORDER OF MAGNITUDE GREATER THAN DIFFERENCES IN BRAIN. HENCE, DIFFERENT DEGREES OF DNA METHYLATION ASSOCIATED WITH CHRONIC OPIOID EXPOSURE ARE UNLIKELY TO EXERT A MAJOR ROLE IN THE REGION-SPECIFICITY OF MU-OPIOID RECEPTOR EXPRESSION IN THE HUMAN BRAIN. 2016 18 3387 25 HOMOCYSTEINE ASSOCIATED GENOMIC DNA HYPERMETHYLATION IN PATIENTS WITH CHRONIC ALCOHOLISM. HIGHER PLASMA HOMOCYSTEINE CONCENTRATIONS CAN INFLUENCE GENOMIC DNA METHYLATION IN PERIPHERAL BLOOD CELLS. IN THE PRESENT CONTROLLED STUDY WE OBSERVED A SIGNIFICANT INCREASE (10%) OF GENOMIC DNA METHYLATION IN PATIENTS WITH ALCOHOLISM (T = -3.16, DF = 158, P = 0.002) WHICH WAS SIGNIFICANTLY ASSOCIATED WITH THEIR ELEVATED HOMOCYSTEINE LEVELS (MULTIPLE LINEAR REGRESSION, P < 0.001). SINCE METHYLATION OF DNA IS AN IMPORTANT EPIGENETIC FACTOR IN REGULATION OF GENE EXPRESSION THESE FINDINGS MAY HAVE IMPORTANT IMPLICATIONS FOR A POSSIBLE SUBSEQUENT DERANGEMENT OF EPIGENETIC CONTROL THESE PATIENTS. 2004 19 507 35 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 2762 40 EXPRESSION OF TET2 ENZYME INDICATES ENHANCED EPIGENETIC MODIFICATION OF CELLS IN PERIODONTITIS. DNA METHYLATION IS AN IMPORTANT EPIGENETIC MECHANISM INVOLVED IN THE REGULATION OF GENE EXPRESSION, AND A REDUCTION IN DNA METHYLATION INFLUENCES CELL-CYCLE PROGRESSION AND CELL DIFFERENTIATION IN INFLAMMATORY CELLS. THE AIM OF THE PRESENT STUDY WAS TO ANALYZE THE DNA-METHYLATION PATTERN AT LOCAL AND GLOBAL/SYSTEMIC LEVELS IN PATIENTS WITH PERIODONTITIS AND GINGIVITIS. TWENTY-ONE SUBJECTS WITH GENERALIZED, SEVERE PERIODONTITIS AND 17 SUBJECTS WITH GINGIVAL INFLAMMATION BUT NO ATTACHMENT LOSS WERE RECRUITED. GINGIVAL BIOPSIES AND PERIPHERAL BLOOD SAMPLES WERE COLLECTED AND PREPARED FOR IMMUNOHISTOCHEMICAL ANALYSIS OF 5-METHYLCYTOSINE (5MC), 5-HYDROXYMETHYLCYTOSINE (5HMC), TEN-ELEVEN TRANSLOCATION 2 (TET2), AND DNA METHYLTRANSFERASE 1 (DNMT1). WHILST A SIMILAR PATTERN FOR 5MC AND 5HMC DNA METHYLATION WAS FOUND IN BOTH TYPES OF LESIONS, A SIGNIFICANTLY LARGER PROPORTION OF TET2-POSITIVE CELLS WAS FOUND IN PERIODONTITIS LESIONS THAN IN GINGIVITIS LESIONS. QUANTITATIVE REAL-TIME PCR ANALYSIS SHOWED NO DIFFERENCES BETWEEN GINGIVITIS AND PERIODONTITIS LESIONS REGARDING EXPRESSION OF TET2 AND ISOCITRATE DEHYDROGENASE (IDH) GENES, WHILE THE GLOBAL LEVEL OF 5HMC WAS SIGNIFICANTLY HIGHER IN BLOOD THAN IN TISSUE IN PATIENTS WITH PERIODONTITIS. IT IS SUGGESTED THAT EPIGENETIC CHANGES ARE MORE COMMON IN PERIODONTITIS LESIONS THAN IN GINGIVITIS LESIONS AND THAT SUCH CHANGES ARE TISSUE SPECIFIC. 2016