1 2422 142 EPIGENETIC SIGNATURES DISCRIMINATE PATIENTS WITH PRIMARY SCLEROSING CHOLANGITIS AND ULCERATIVE COLITIS FROM PATIENTS WITH ULCERATIVE COLITIS. BACKGROUND: PRIMARY SCLEROSING CHOLANGITIS (PSC) IS A CHRONIC INFLAMMATORY LIVER DISEASE AFFECTING THE INTRA- AND EXTRAHEPATIC BILE DUCTS, AND IS STRONGLY ASSOCIATED WITH ULCERATIVE COLITIS (UC). IN THIS STUDY, WE EXPLORED THE PERIPHERAL BLOOD DNA METHYLOME AND ITS IMMUNE CELL COMPOSITION IN PATIENTS WITH PSC-UC, UC, AND HEALTHY CONTROLS (HC) WITH THE AIM TO DEVELOP A PREDICTIVE ASSAY IN DISTINGUISHING PATIENTS WITH PSC-UC FROM THOSE WITH UC ALONE. METHODS: THE PERIPHERAL BLOOD DNA METHYLOME OF MALE PATIENTS WITH PSC AND CONCOMITANT UC, UC AND HCS WAS PROFILED USING THE ILLUMINA HUMANMETHYLATION INFINIUM EPIC BEADCHIP (850K) ARRAY. DIFFERENTIALLY METHYLATED CPG POSITION (DMP) AND REGION (DMR) ANALYSES WERE PERFORMED ALONGSIDE GRADIENT BOOSTING CLASSIFICATION ANALYSES TO DISCERN PSC-UC FROM UC PATIENTS. AS OBSERVED DIFFERENCES IN THE DNA METHYLOME COULD BE THE RESULT OF DIFFERENCES IN CELLULAR POPULATIONS, WE ADDITIONALLY EMPLOYED MASS CYTOMETRY (CYTOF) TO CHARACTERIZE THE IMMUNE CELL COMPOSITIONS. RESULTS: GENOME WIDE METHYLATION ANALYSIS DID NOT REVEAL LARGE DIFFERENCES BETWEEN PSC-UC AND UC PATIENTS NOR HCS. NONETHELESS, USING GRADIENT BOOSTING WE WERE CAPABLE OF DISCERNING PSC-UC FROM UC WITH AN AREA UNDER THE RECEIVER OPERATOR CURVE (AUROC) OF 0.80. FOUR CPG SITES ANNOTATED TO THE NINJ2 GENE WERE FOUND TO STRONGLY CONTRIBUTE TO THE PREDICTIVE PERFORMANCE. WHILE CYTOF ANALYSES CORROBORATED THE LARGELY SIMILAR BLOOD CELL COMPOSITION AMONG PATIENTS WITH PSC-UC, UC AND HC, A HIGHER ABUNDANCE OF MYELOID CELLS WAS OBSERVED IN UC COMPARED TO PSC-UC PATIENTS. CONCLUSION: DNA METHYLATION ENABLES DISCERNING PSC-UC FROM UC PATIENTS, WITH A POTENTIAL FOR BIOMARKER DEVELOPMENT. 2022 2 1607 36 DNA METHYLATION, COLON CANCER AND MEDITERRANEAN DIET: RESULTS FROM THE EPIC-ITALY COHORT. THE BIOLOGICAL MECHANISMS THROUGH WHICH ADHERENCE TO MEDITERRANEAN DIET (MD) PROTECTS AGAINST COLON CANCER (CC) ARE POORLY UNDERSTOOD. EVIDENCE SUGGESTS THAT CHRONIC INFLAMMATION MAY BE IMPLICATED IN THE PATHWAY. BOTH DIET AND CC ARE RELATED TO EPIGENETIC REGULATION. WE PERFORMED A NESTED CASE-CONTROL STUDY ON 161 PAIRS FROM THE ITALIAN COMPONENT OF THE EUROPEAN PROSPECTIVE INVESTIGATION INTO CANCER AND NUTRITION (EPIC) COHORT, IN WHICH WE LOOKED FOR THE METHYLATION SIGNALS IN DNA EXTRACTED FROM LEUCOCYTES ASSOCIATED WITH BOTH CC AND MD IN 995 CPGS LOCATED IN 48 INFLAMMATION GENES. THE DNA METHYLATION SIGNALS DETECTED IN THIS ANALYSIS WERE VALIDATED IN A SUBGROUP OF 47 CASE-CONTROL PAIRS AND FURTHER REPLICATED (WHERE VALIDATED) IN 95 NEW PAIRS BY MEANS OF PYROSEQUENCING. AMONG THE CPG SITES SELECTED A-PRIORI IN INFLAMMATION-RELATED GENES, SEVEN CPG SITES WERE FOUND TO BE ASSOCIATED WITH CC STATUS AND WITH MD, IN LINE WITH ITS PROTECTIVE EFFECT. ONLY TWO CPG SITES (CG17968347-SERPINE1 AND CG20674490-RUNX3) WERE VALIDATED USING BISULPHITE PYROSEQUENCING AND, AFTER REPLICATION, WE FOUND THAT DNA METHYLATION OF CG20674490-RUNX3 MAY BE A POTENTIAL MOLECULAR MEDIATOR EXPLAINING THE PROTECTIVE EFFECT OF MD ON CC ONSET. THE USE OF A 'MEET-IN-THE-MIDDLE' APPROACH TO IDENTIFY THE OVERLAP BETWEEN EXPOSURE AND PREDICTIVE MARKERS OF DISEASE IS INNOVATIVE IN STUDIES ON THE RELATIONSHIP BETWEEN DIET AND CANCER, IN WHICH EXPOSURE ASSESSMENT IS DIFFICULT AND THE MECHANISMS THROUGH WHICH THE NUTRIENTS EXERT THEIR PROTECTIVE EFFECT IS LARGELY UNKNOWN. 2019 3 2048 35 EPIGENETIC CLUSTERING OF LUNG ADENOCARCINOMAS BASED ON DNA METHYLATION PROFILES IN ADJACENT LUNG TISSUE: ITS CORRELATION WITH SMOKING HISTORY AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. THE AIM OF THIS STUDY WAS TO CLARIFY THE SIGNIFICANCE OF DNA METHYLATION ALTERATIONS DURING LUNG CARCINOGENESIS. INFINIUM ASSAY WAS PERFORMED USING 139 PAIRED SAMPLES OF NON-CANCEROUS LUNG TISSUE (N) AND TUMOROUS TISSUE (T) FROM A LEARNING COHORT OF PATIENTS WITH LUNG ADENOCARCINOMAS (LADCS). FIFTY PAIRED N AND T SAMPLES FROM A VALIDATION COHORT WERE ALSO ANALYZED. DNA METHYLATION ALTERATIONS ON 1,928 PROBES OCCURRED IN N SAMPLES RELATIVE TO NORMAL LUNG TISSUE FROM PATIENTS WITHOUT PRIMARY LUNG TUMORS, AND WERE INHERITED BY, OR STRENGTHENED IN, T SAMPLES. UNSUPERVISED HIERARCHICAL CLUSTERING USING DNA METHYLATION LEVELS IN N SAMPLES ON ALL 26,447 PROBES SUBCLUSTERED PATIENTS INTO CLUSTER I (N = 32), CLUSTER II (N = 35) AND CLUSTER III (N = 72). LADCS IN CLUSTER I DEVELOPED FROM THE INFLAMMATORY BACKGROUND IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IN HEAVY SMOKERS AND WERE LOCALLY INVASIVE. MOST PATIENTS IN CLUSTER II WERE NON-SMOKERS AND HAD A FAVORABLE OUTCOME. LADCS IN CLUSTER III DEVELOPED IN LIGHT SMOKERS WERE MOST AGGRESSIVE (FREQUENTLY SHOWING LYMPHATIC AND BLOOD VESSEL INVASION, LYMPH NODE METASTASIS AND AN ADVANCED PATHOLOGICAL STAGE), AND HAD A POOR OUTCOME. DNA METHYLATION LEVELS OF HALLMARK GENES FOR EACH CLUSTER, SUCH AS IRX2, HOXD8, SPARCL1, RGS5 AND EI24, WERE AGAIN CORRELATED WITH CLINICOPATHOLOGICAL CHARACTERISTICS IN THE VALIDATION COHORT. DNA METHYLATION PROFILES REFLECTING CARCINOGENETIC FACTORS SUCH AS SMOKING AND COPD APPEAR TO BE ESTABLISHED IN NON-CANCEROUS LUNG TISSUE FROM PATIENTS WITH LADCS AND MAY DETERMINE THE AGGRESSIVENESS OF TUMORS DEVELOPING IN INDIVIDUAL PATIENTS, AND THUS PATIENT OUTCOME. 2014 4 6190 40 THE IMPACT OF METHYLATION QUANTITATIVE TRAIT LOCI (MQTLS) ON ACTIVE SMOKING-RELATED DNA METHYLATION CHANGES. BACKGROUND: METHYLATION QUANTITATIVE TRAIT LOCI (MQTLS) ARE THE GENETIC VARIANTS THAT MAY AFFECT THE DNA METHYLATION PATTERNS OF CPG SITES. HOWEVER, THEIR ROLES IN INFLUENCING THE DISTURBANCES OF SMOKING-RELATED EPIGENETIC CHANGES HAVE NOT BEEN WELL ESTABLISHED. THIS STUDY WAS CONDUCTED TO ADDRESS WHETHER MQTLS EXIST IN THE VICINITY OF SMOKING-RELATED CPG SITES (+/- 50 KB) AND TO EXAMINE THEIR ASSOCIATIONS WITH SMOKING EXPOSURE AND ALL-CAUSE MORTALITY IN OLDER ADULTS. RESULTS: WE OBTAINED DNA METHYLATION PROFILES IN WHOLE BLOOD SAMPLES BY ILLUMINA INFINIUM HUMAN METHYLATION 450 BEADCHIP ARRAY OF TWO INDEPENDENT SUBSAMPLES OF THE ESTHER STUDY (DISCOVERY SET, N = 581; VALIDATION SET, N = 368) AND THEIR CORRESPONDING GENOTYPING DATA USING THE ILLUMINA INFINIUM ONCOARRAY BEADCHIP. AFTER CORRECTION FOR MULTIPLE TESTING (FDR), WE SUCCESSFULLY IDENTIFIED THAT 70 OUT OF 151 PREVIOUSLY REPORTED SMOKING-RELATED CPG SITES WERE SIGNIFICANTLY ASSOCIATED WITH 192 SNPS WITHIN THE 50 KB SEARCH WINDOW OF EACH LOCUS. THE 192 MQTLS SIGNIFICANTLY INFLUENCED THE ACTIVE SMOKING-RELATED DNA METHYLATION CHANGES, WITH PERCENTAGE CHANGES RANGING FROM 0.01 TO 18.96%, ESPECIALLY FOR THE WEAKLY/MODERATELY SMOKING-RELATED CPG SITES. HOWEVER, THESE IDENTIFIED MQTLS WERE NOT DIRECTLY ASSOCIATED WITH ACTIVE SMOKING EXPOSURE OR ALL-CAUSE MORTALITY. CONCLUSIONS: OUR FINDINGS CLEARLY DEMONSTRATED THAT IF NOT DEALT WITH PROPERLY, THE MQTLS MIGHT IMPAIR THE POWER OF EPIGENETIC-BASED MODELS OF SMOKING EXPOSURE TO A CERTAIN EXTENT. IN ADDITION, SUCH GENETIC VARIANTS COULD BE THE KEY FACTOR TO DISTINGUISH BETWEEN THE HERITABLE AND SMOKING-INDUCED IMPACT ON EPIGENOME DISPARITIES. THESE MQTLS ARE OF SPECIAL IMPORTANCE WHEN DNA METHYLATION MARKERS MEASURED BY ILLUMINA INFINIUM ASSAY ARE USED FOR ANY COMPARATIVE POPULATION STUDIES RELATED TO SMOKING-RELATED CANCERS AND CHRONIC DISEASES. 2017 5 1739 44 EARLY DNA METHYLATION CHANGES IN CHILDREN DEVELOPING BETA CELL AUTOIMMUNITY AT A YOUNG AGE. AIMS/HYPOTHESIS: TYPE 1 DIABETES IS A CHRONIC AUTOIMMUNE DISEASE OF COMPLEX AETIOLOGY, INCLUDING A POTENTIAL ROLE FOR EPIGENETIC REGULATION. PREVIOUS EPIGENOMIC STUDIES FOCUSED MAINLY ON CLINICALLY DIAGNOSED INDIVIDUALS. THE AIM OF THE STUDY WAS TO ASSESS EARLY DNA METHYLATION CHANGES ASSOCIATED WITH TYPE 1 DIABETES ALREADY BEFORE THE DIAGNOSIS OR EVEN BEFORE THE APPEARANCE OF AUTOANTIBODIES. METHODS: REDUCED REPRESENTATION BISULPHITE SEQUENCING (RRBS) WAS APPLIED TO STUDY DNA METHYLATION IN PURIFIED CD4(+) T CELL, CD8(+) T CELL AND CD4(-)CD8(-) CELL FRACTIONS OF 226 PERIPHERAL BLOOD MONONUCLEAR CELL SAMPLES LONGITUDINALLY COLLECTED FROM SEVEN TYPE 1 DIABETES-SPECIFIC AUTOANTIBODY-POSITIVE INDIVIDUALS AND CONTROL INDIVIDUALS MATCHED FOR AGE, SEX, HLA RISK AND PLACE OF BIRTH. WE ALSO EXPLORED CORRELATIONS BETWEEN DNA METHYLATION AND GENE EXPRESSION USING RNA SEQUENCING DATA FROM THE SAME SAMPLES. TECHNICAL VALIDATION OF RRBS RESULTS WAS PERFORMED USING PYROSEQUENCING. RESULTS: WE IDENTIFIED 79, 56 AND 45 DIFFERENTIALLY METHYLATED REGIONS IN CD4(+) T CELLS, CD8(+) T CELLS AND CD4(-)CD8(-) CELL FRACTIONS, RESPECTIVELY, BETWEEN TYPE 1 DIABETES-SPECIFIC AUTOANTIBODY-POSITIVE INDIVIDUALS AND CONTROL PARTICIPANTS. THE ANALYSIS OF PRE-SEROCONVERSION SAMPLES IDENTIFIED DNA METHYLATION SIGNATURES AT THE VERY EARLY STAGE OF DISEASE, INCLUDING DIFFERENTIAL METHYLATION AT THE PROMOTER OF IRF5 IN CD4(+) T CELLS. FURTHER, WE VALIDATED RRBS RESULTS USING PYROSEQUENCING AT THE FOLLOWING CPG SITES: CHR19:18118304 IN THE PROMOTER OF ARRDC2; CHR21:47307815 IN THE INTRON OF PCBP3; AND CHR14:81128398 IN THE INTERGENIC REGION NEAR TRAF3 IN CD4(+) T CELLS. CONCLUSIONS/INTERPRETATION: THESE PRELIMINARY RESULTS PROVIDE NOVEL INSIGHTS INTO CELL TYPE-SPECIFIC DIFFERENTIAL EPIGENETIC REGULATION OF GENES, WHICH MAY CONTRIBUTE TO TYPE 1 DIABETES PATHOGENESIS AT THE VERY EARLY STAGE OF DISEASE DEVELOPMENT. SHOULD THESE FINDINGS BE VALIDATED, THEY MAY SERVE AS A POTENTIAL SIGNATURE USEFUL FOR DISEASE PREDICTION AND MANAGEMENT. 2022 6 4242 33 METHYLATION STATUS OF ALU AND LINE-1 INTERSPERSED REPETITIVE SEQUENCES IN BEHCET'S DISEASE PATIENTS. BEHCET'S DISEASE (BD) IS A MULTISYSTEM CHRONIC INFLAMMATORY DISEASE. THE PATHOLOGY IS BELIEVED TO INVOLVE BOTH GENETIC SUSCEPTIBILITY AND ENVIRONMENTAL FACTORS. HYPOMETHYLATION LEADING TO ACTIVATION OF INTERSPERSED REPETITIVE SEQUENCES (IRSS) SUCH AS LINE-1 AND ALU CONTRIBUTES TO THE PATHOLOGIES OF AUTOIMMUNE DISEASES AND CANCER. HEREIN, THE EPIGENETIC CHANGES OF IRSS IN BD WERE EVALUATED USING COMBINED BISULFITE RESTRICTION ANALYSIS-INTERSPERSED REPETITIVE SEQUENCES (COBRA-IRS). DNA FROM NEUTROPHILS AND PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) OF BD PATIENTS WITH OCULAR INVOLVEMENT THAT WERE IN ACTIVE OR INACTIVE STATES AND HEALTHY CONTROLS WERE USED TO ANALYZE LINE-1 AND ALU METHYLATION LEVELS. FOR ALU SEQUENCES, SIGNIFICANT DIFFERENCES WERE OBSERVED IN THE FREQUENCY OF (U)C(U)C ALLELES BETWEEN PBMCS OF PATIENTS AND CONTROLS (P = 0.03), AND BETWEEN INACTIVE PATIENTS AND CONTROLS (P = 0.03). FOR NEUTROPHILS, THE FREQUENCY OF (U)C(U)C WAS SIGNIFICANTLY HIGHER BETWEEN PATIENTS AND CONTROLS (P = 0.006) AND BETWEEN INACTIVE PATIENTS AND CONTROLS (P = 0.002). THE PARTIAL METHYLATION ((U)C(M)C + (M)C(U)C) FREQUENCIES OF ALU BETWEEN INACTIVE PATIENTS AND CONTROL SAMPLES ALSO DIFFERED (P = 0.02). NO STATISTICALLY SIGNIFICANT DIFFERENCES FOR LINE-1 WERE DETECTED. THUS, CHANGES IN THE METHYLATION LEVEL OF IRS ELEMENTS MIGHT CONTRIBUTE TO THE PATHOGENESIS OF BD. THE ROLE OF ALU TRANSCRIPTS IN BD SHOULD BE INVESTIGATED FURTHER. 2016 7 1909 38 ENRICHMENT OF GENOMIC PATHWAYS BASED ON DIFFERENTIAL DNA METHYLATION PROFILES ASSOCIATED WITH CHRONIC MUSCULOSKELETAL PAIN IN OLDER ADULTS: AN EXPLORATORY STUDY. OUR STUDY AIMED TO IDENTIFY DIFFERENTIALLY METHYLATED CPGS/REGIONS AND THEIR ENRICHED GENOMIC PATHWAYS ASSOCIATED WITH UNDERLYING CHRONIC MUSCULOSKELETAL PAIN IN OLDER INDIVIDUALS. WE RECRUITED COGNITIVELY HEALTHY OLDER ADULTS WITH (N = 20) AND WITHOUT (N = 9) SELF-REPORTED MUSCULOSKELETAL PAIN AND COLLECTED DNA FROM PERIPHERAL BLOOD THAT WAS ANALYZED USING METHYLATIONEPIC ARRAYS. WE IDENTIFIED 31,739 HYPERMETHYLATED CPG AND 10,811 HYPOMETHYLATED CPG PROBES (PS