1 2151 192 EPIGENETIC MECHANISM IN SEARCH FOR THE PATHOMECHANISM OF DIABETIC NEUROPATHY DEVELOPMENT IN DIABETES MELLITUS TYPE 1 (T1DM). OBJECTIVE: THE AIM OF THIS STUDY WAS TO CHECK THE HYPOTHESIS CONCERNING THE CRUCIAL ROLE OF DNA METHYLATION (ONE OF THE EPIGENETIC MECHANISMS) WITHIN SELECTED GENES RELATED TO THE DESTRUCTION AND REGENERATION OF NEURAL CELLS AND ITS INPUT IN THE PATHOGENESIS OF DIABETIC NEUROPATHY, USING A MODEL OF THE DNA IN PERIPHERAL BLOOD CELLS. METHODS: A CROSS-SECTIONAL, CASE-CONTROL STUDY WAS CONDUCTED, CONSISTING OF 24 ADULT TYPE 1 DIABETES MELITUS (T1DM) PATIENTS WITH AUTONOMIC NEUROPATHY (CAN), 25 T1DM PATIENTS WITHOUT NEUROPATHY AND 25 MATCHED, HEALTHY ADULTS ACTING AS A CONTROL (CTRL). THE EWING'S TESTS, USING THE PROSCICARD APPARATUS (MEWICON CATEEM-TEC GMBH), WAS EMPLOYED TO ASSESS THE SEVERITY OF THE PATIENTS' SYMPTOMS OF AUTONOMIC NEUROPATHY. FOR DNA METHYLATION ANALYSIS, DNA MATERIAL OF EACH SAMPLE DNA AFTER BISULFITE CONVERSION WAS USED FOR THE HYBRIDIZATION OF BEADCHIPS (INFINIUM METHYLATION EPIC KIT, ILLUMINA), AND IMAGED ON THE ILLUMINA HISCAN. THE CHANGES IN THE EXPRESSION OF SELECTED GENES WERE EXAMINED USING REAL-TIME PCR. PROBES WERE LABELED USING FLUORESCEIN AMIDITE, FAM (THERMO FISHER SCIENTIFIC). AMPLIFICATION WAS PERFORMED USING THE CONTINUOUS FLUORESCENCE DETECTION 7900 HT FAST REAL-TIME PCR SYSTEM (THERMO FISHER SCIENTIFIC). THE EXPRESSION RATIO OF THE TARGET MRNA WAS NORMALIZED TO THE LEVEL OF 18S RNA AND COMPARED WITH THE CONTROL. STATISTICAL ANALYSIS WAS PERFORMED USING STATISTICA VERSION 13.1. THE STATISTICALLY SIGNIFICANT RESULTS WERE RECOGNIZED, WITH A VALUE OF P < 0.05. RESULTS: CLINICAL ANALYSIS OF THE INVESTIGATED GROUPS REVEALED A SIGNIFICANTLY HIGHER PERCENTAGE OF PERSONAL INSULIN PUMP USERS IN THE GROUP WITHOUT NEUROPATHY. THE GLUCOSE METABOLIC CONTROL, BASED ON THE HBA1C LEVEL ANALYSIS, WAS ALSO SIGNIFICANTLY BETTER IN T1DM PATIENTS WITHOUT CAN. THE BUMPHUNTER METHOD FOR DNA METHYLATION ANALYSIS SHOWED STATISTICALLY SIGNIFICANT REGIONS RELATED TO THE GENES INVOLVED IN NERVE REGENERATION NINJURIN 2 (NINJ2) AND FUNCTIONALITY (BR SERINE/THREONINE KINASE 2 BRSK2, CLAUDIN 4 CLDN4). WHEN COMPARED WITH T1DM PATIENTS WITHOUT NEUROPATHY, T1DM PATIENTS WITH NEUROPATHY SHOWED SIGNIFICANTLY INCREASED METHYLATION IN THE FIRST NINJ2 AXON, AND A LOWER LEVEL OF DNA METHYLATION IN THE REGION OF THE FIRST INTRON OF BRSK2, AS WELL AS THE CLDN4 5'UTR REGIONS. THE QRT-PCR RESULTS CONFIRMED THE DECREASED EXPRESSION OF NINJ2 AND CLDN4 GENES IN PATIENTS WITH T1DM WITH CAN. CONCLUSIONS: THE DIFFERENT DNA METHYLATION PROFILES, CORRELATING WITH THE EXPRESSION OF GENES RELATED TO NERVOUS TISSUE DEVELOPMENT AND REGENERATION IN PATIENTS WITH T1DM WITH AUTONOMIC NEUROPATHY PROVIDE EVIDENCE FOR THE ROLE OF EPIGENETIC MECHANISMS PROMOTING THE DEVELOPMENT OF CAN, A CHRONIC COMPLICATION OF T1DM. 2020 2 1607 30 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 1909 43 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