1 3441 160 HYPERMETHYLATION IN GENE PROMOTERS ARE INDUCED BY CHRONIC EXPOSURE TO BENZENE, TOLUENE, ETHYLBENZENE AND XYLENES. BACKGROUND AND OBJECTIVE: GAS STATION ATTENDANTS ARE OCCUPATIONALLY EXPOSED TO BENZENE, TOLUENE, ETHYLBENZENE AND XYLENE (BTEX) COMPOUNDS AND THUS MORE SUSCEPTIBLE TO THE BIOLOGICAL EFFECTS OF THIS MIXTURE PRESENT IN GASOLINE, ESPECIALLY DUE TO THE CARCINOGENICITY OF BENZENE. FURTHERMORE, THE HARMFUL EFFECTS OF BTEX EXPOSURE MAY BE POTENTIATED BY GENETIC AND EPIGENETIC INACTIVATION OF CRITICAL GENES. THE OBJECTIVE WAS TO EVALUATE SUCH GENE-BTEX INTERACTIONS ACCESSING THE PROMOTER METHYLATION STATUS OF P14ARF, P16INK4A AND GSTP1 IN PERIPHERAL BLOOD LEUKOCYTE SAMPLES. MATERIALS AND METHODS: THE 59 EXPOSED AND 68 UNEXPOSED PARTICIPANTS FROM RIO DE JANEIRO, BRAZIL, WERE INCLUDED. THE PROMOTER METHYLATION STATUS WAS ACCESSED BY METHYLATION-SPECIFIC PCR (MSP) AND GSTP1 ILE105VAL POLYMORPHISM WAS INVESTIGATED BY PCR-RESTRICTION FRAGMENT LENGTH POLYMORPHISM (PCR-RFLP) TECHNIQUE. RESULTS: BOTH P14ARF AND P16INK4A WERE SIGNIFICANTLY HYPERMETHYLATED IN EXPOSED SUBJECTS COMPARED TO UNEXPOSED (P = 0.004 AND P<0.001, RESPECTIVELY). ADDITIONALLY, P16INK4A HYPERMETHYLATION IN THE EXPOSED GROUP WAS CORRELATED WITH CHROMOSOMAL ABNORMALITIES (CAS) (P = 0.018), THUS HIGHLIGHTING THE INFLUENCE OF THE GENE-ENVIRONMENT INTERACTIONS ON GENOME INSTABILITY. NOTEWORTHY, P16INK4A METHYLATION WAS SIGNIFICANTLY ASSOCIATED WITH MISCARRIAGE AMONG FEMALE ATTENDANTS (P = 0.047), IN WHICH THOSE WHO REPORTED MISCARRIAGE EXHIBITED HYPERMETHYLATION IN AT LEAST 2 OF THE 3 GENES ANALYZED. THE GSTP1 HETEROZYGOTE GENOTYPE, WHICH COULD AFFECT THE METABOLISM OF BENZENE DETOXIFICATION, WAS FOUND IN BOTH GROUPS BUT WAS MORE FREQUENT IN THOSE OCCUPATIONALLY EXPOSED. NO SIGNIFICANT ASSOCIATION WAS OBSERVED BETWEEN GSTP1 GENOTYPES AND METHYLATION STATUS. CONCLUSION: TOGETHER, THESE FINDINGS INDICATE THAT GAS STATION ATTENDANTS WITH THE AFOREMENTIONED EPIGENETIC AND GENETIC PROFILES MAY BE AT GREATER RISK OF OCCUPATIONAL BTEX EXPOSURE-INDUCED GENOME INSTABILITY, WHICH COULD REQUIRE CONCERTED EFFORTS TO ESTABLISH MORE PREVENTIVE ACTIONS AND CONSTANT BIOMONITORING IN GAS STATION ATTENDANTS. 2020 2 1846 35 EFFECTS OF TWO TYPES OF ENERGY RESTRICTION ON METHYLATION LEVELS OF ADIPONECTIN RECEPTOR 1 AND LEPTIN RECEPTOR OVERLAPPING TRANSCRIPT IN A MOUSE MAMMARY TUMOUR VIRUS-TRANSFORMING GROWTH FACTOR-ALPHA BREAST CANCER MOUSE MODEL. THE ROLE OF ADIPONECTIN AND LEPTIN SIGNALLING PATHWAYS HAS BEEN SUGGESTED TO PLAY IMPORTANT ROLES IN THE PROTECTIVE EFFECTS OF ENERGY RESTRICTION (ER) ON MAMMARY TUMOUR (MT) DEVELOPMENT. TO STUDY THE EFFECTS OF ER ON THE METHYLATION LEVELS IN ADIPONECTIN RECEPTOR 1 (ADIPOR1) AND LEPTIN RECEPTOR OVERLAPPING TRANSCRIPT (LEPROT) GENES USING THE PYROSEQUENCING METHOD IN MAMMARY FAT PAD TISSUE, MOUSE MAMMARY TUMOUR VIRUS-TRANSFORMING GROWTH FACTOR-ALPHA (MMTV-TGF-ALPHA) FEMALE MICE WERE RANDOMLY ASSIGNED TO AD LIBITUM (AL), CHRONIC ER (CER, 15 % ER) OR INTERMITTENT ER (3 WEEKS AL AND 1 WEEK 60 % ER IN CYCLIC PERIODS) GROUPS AT 10 WEEKS OF AGE UNTIL 82 WEEKS OF AGE. THE METHYLATION LEVELS OF ADIPOR1 IN THE CER GROUP WERE HIGHER THAN THOSE IN THE AL GROUP AT WEEK 49/50 (P < 0.05), WHILE THE LEVELS OF METHYLATION FOR ADIPOR1 AND LEPROT GENES WERE SIMILAR AMONG THE OTHER GROUPS. ALSO, THE METHYLATION LEVELS AT CPG2 AND CPG3 REGIONS OF THE PROMOTER REGION OF THE ADIPOR1 GENE IN THE CER GROUP WERE THREE TIMES HIGHER (P < 0.05), WHILE CPG1 ISLAND OF LEPROT METHYLATION WAS SIGNIFICANTLY LOWER COMPARED WITH THE OTHER GROUPS (P < 0.05). ADIPONECTIN AND LEPTIN GENE EXPRESSION LEVELS WERE CONSISTENT WITH THE METHYLATION LEVELS. WE ALSO OBSERVED A CHANGE WITH AGEING IN METHYLATION LEVELS OF THESE GENES. THESE RESULTS INDICATE THAT DIFFERENT TYPES OF ER MODIFY METHYLATION LEVELS OF ADIPOR1 AND LEPROT IN DIFFERENT WAYS AND CER HAD A MORE SIGNIFICANT EFFECT ON METHYLATION LEVELS OF BOTH GENES. EPIGENETIC REGULATION OF THESE GENES MAY PLAY IMPORTANT ROLES IN THE PREVENTIVE EFFECTS OF ER AGAINST MT DEVELOPMENT AND AGEING PROCESSES. 2021 3 2921 36 GENE-SPECIFIC DIFFERENTIAL DNA METHYLATION AND CHRONIC ARSENIC EXPOSURE IN AN EPIGENOME-WIDE ASSOCIATION STUDY OF ADULTS IN BANGLADESH. BACKGROUND: INORGANIC ARSENIC IS ONE OF THE MOST COMMON NATURALLY OCCURRING CONTAMINANTS FOUND IN THE ENVIRONMENT. ARSENIC IS ASSOCIATED WITH A NUMBER OF HEALTH OUTCOMES, WITH EPIGENETIC MODIFICATION SUGGESTED AS A POTENTIAL MECHANISM OF TOXICITY. OBJECTIVE: AMONG A SAMPLE OF 400 ADULT PARTICIPANTS, WE EVALUATED THE ASSOCIATION BETWEEN ARSENIC EXPOSURE, AS MEASURED BY BLOOD AND URINARY TOTAL ARSENIC CONCENTRATIONS, AND EPIGENOME-WIDE WHITE BLOOD CELL DNA METHYLATION. METHODS: WE USED LINEAR REGRESSION MODELS TO EXAMINE THE ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND METHYLATION AT EACH CPG SITE, ADJUSTED FOR SEX, AGE, AND BATCH. DIFFERENTIALLY METHYLATED LOCI WERE SUBSEQUENTLY EXAMINED IN RELATION TO CORRESPONDING GENE EXPRESSION FOR FUNCTIONAL EVIDENCE OF GENE REGULATION. RESULTS: IN ADJUSTED ANALYSES, WE OBSERVED FOUR DIFFERENTIALLY METHYLATED CPG SITES WITH URINARY TOTAL ARSENIC CONCENTRATION AND THREE DIFFERENTIALLY METHYLATED CPG SITES WITH BLOOD ARSENIC CONCENTRATION, BASED ON THE BONFERRONI-CORRECTED SIGNIFICANCE THRESHOLD OF P < 1 X 10(-7). METHYLATION OF PLA2G2C (PROBE CG04605617) WAS THE MOST SIGNIFICANTLY ASSOCIATED LOCUS IN RELATION TO BOTH URINARY (P = 3.40 X 10(-11)) AND BLOOD ARSENIC CONCENTRATIONS (P = 1.48 X 10(-11)). THREE ADDITIONAL NOVEL METHYLATION LOCI-SQSTM1 (CG01225779), SLC4A4 (CG06121226), AND IGH (CG13651690)--WERE ALSO SIGNIFICANTLY ASSOCIATED WITH ARSENIC EXPOSURE. FURTHER, THERE WAS EVIDENCE OF METHYLATION-RELATED GENE REGULATION BASED ON GENE EXPRESSION FOR A SUBSET OF DIFFERENTIALLY METHYLATED LOCI. CONCLUSIONS: WE OBSERVED SIGNIFICANT ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND GENE-SPECIFIC DIFFERENTIAL WHITE BLOOD CELL DNA METHYLATION, SUGGESTING THAT EPIGENETIC MODIFICATIONS MAY BE AN IMPORTANT PATHWAY UNDERLYING ARSENIC TOXICITY. THE SPECIFIC DIFFERENTIALLY METHYLATED LOCI IDENTIFIED MAY INFORM POTENTIAL PATHWAYS FOR FUTURE INTERVENTIONS. 2015 4 1847 36 EFFECTS OF VARIOUS ENVIRONMENTS ON EPIGENETIC SETTINGS AND CHROMOSOMAL DAMAGE. AIR POLLUTION IS A DOMINANT ENVIRONMENTAL EXPOSURE FACTOR WITH SIGNIFICANT HEALTH CONSEQUENCES. UNEXPECTEDLY, RESEARCH IN A HEAVILY POLLUTED REGION OF THE CZECH REPUBLIC, WITH TRADITIONAL HEAVY INDUSTRY, REVEALED REPEATEDLY THE LOWEST FREQUENCY OF MICRONUCLEI IN THE SEASON WITH THE HIGHEST CONCENTRATIONS OF AIR POLLUTANTS INCLUDING CARCINOGENIC BENZO[A]PYRENE (B[A]P). MOLECULAR FINDINGS HAVE BEEN COLLECTED FOR MORE THAN 10 YEARS FROM VARIOUS LOCATIONS OF THE CZECH REPUBLIC, WITH DIFFERING QUALITY OF AMBIENT AIR. PRELIMINARY CONCLUSIONS HAVE SUGGESTED ADAPTATION OF THE POPULATION FROM THE POLLUTED LOCALITY (OSTRAVA, MORAVIAN-SILESIAN REGION (MSR)) TO CHRONIC AIR POLLUTION EXPOSURE. IN THIS STUDY WE UTILIZE THE PREVIOUS FINDINGS AND, FOR THE FIRST TIME, INVESTIGATE MICRONUCLEI (MN) FREQUENCY BY TYPE: (I) CENTROMERE POSITIVE (CEN+) MN, REPRESENTING CHROMOSOMAL LOSSES, AND (II) CENTROMERE NEGATIVE (CEN-) MN REPRESENTING CHROMOSOMAL BREAKS. AS PREVIOUS RESULTS INDICATED DIFFERENCES BETWEEN POPULATIONS IN THE EXPRESSION OF XRCC5, A GENE INVOLVED IN THE NON-HOMOLOGOUS END-JOINING (NHEJ) REPAIR PATHWAY, POSSIBLE VARIATIONS IN EPIGENETIC SETTINGS IN THIS GENE WERE ALSO INVESTIGATED. THIS NEW RESEARCH WAS CONDUCTED IN TWO SEASONS IN THE GROUPS FROM TWO LOCALITIES WITH DIFFERENT AIR QUALITY LEVELS (OSTRAVA (OS) AND PRAGUE (PG)). THE OBTAINED NEW RESULTS SHOW SIGNIFICANTLY LOWER FREQUENCIES OF CHROMOSOMAL BREAKS IN THE OS SUBJECTS, RELATED TO THE HIGHEST AIR POLLUTION LEVELS (P < 0.001). IN CONTRAST, CHROMOSOMAL LOSSES WERE COMPARABLE BETWEEN BOTH GROUPS. IN ADDITION, SIGNIFICANTLY LOWER DNA METHYLATION WAS FOUND IN 14.3% OF THE ANALYZED CPG LOCI OF XRCC5 IN THE POPULATION FROM OS. IN CONCLUSION, THE EPIGENETIC ADAPTATION (HYPOMETHYLATION) IN XRCC5 INVOLVED IN THE NHEJ REPAIR PATHWAY IN THE POPULATION FROM THE POLLUTED REGION, WAS SUGGESTED AS A REASON FOR THE REDUCED LEVEL OF CHROMOSOMAL BREAKS. FURTHER RESEARCH IS NEEDED TO EXPLORE THE ADDITIONAL MECHANISMS, INCLUDING GENETIC ADAPTATION. 2023 5 1607 31 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 6 3125 21 GHSR DNA HYPERMETHYLATION IS A COMMON EPIGENETIC ALTERATION OF HIGH DIAGNOSTIC VALUE IN A BROAD SPECTRUM OF CANCERS. IDENTIFICATION OF A SINGLE MOLECULAR TRAIT THAT IS DETERMINANT OF COMMON MALIGNANCIES MAY SERVE AS A POWERFUL DIAGNOSTIC SUPPLEMENT TO CANCER TYPE-SPECIFIC MARKERS. HERE, WE REPORT A DNA METHYLATION MARK THAT IS CHARACTERISTIC OF SEVEN STUDIED MALIGNANCIES, NAMELY CANCERS OF LUNG, BREAST, PROSTATE, PANCREAS, COLORECTUM, GLIOBLASTOMA AND B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) (N = 137). THIS MARK WAS DEFINED BY SUBSTANTIAL HYPERMETHYLATION AT THE PROMOTER AND FIRST EXON OF GROWTH HORMONE SECRETAGOUGE RECEPTOR (GHSR) THROUGH BISULFITE PYROSEQUENCING. THE DEGREE OF ABERRANT METHYLATION WAS CAPABLE OF ACCURATE DISCRIMINATION BETWEEN CANCER AND CONTROL SAMPLES. THE HIGHEST SENSITIVITY AND SPECIFICITY OF CANCER DETECTION WAS ACHIEVED FOR CANCERS OF PANCREAS, LUNG, BREAST AND CLL YIELDING THE AREA UNDER THE CURVE (AUC) VALUES OF 1.0000, 0.9952, 0.9800 AND 0.9400, RESPECTIVELY. NARROWING TO A SINGLE CPG SITE WITHIN THE GENE'S PROMOTER OR FOUR CONSECUTIVE CPG UNITS OF THE HIGHEST METHYLATION LEVELS WITHIN THE FIRST EXON IMPROVED THE DETECTION POWER. GHSR HYPERMETHYLATION WAS DETECTED ALREADY AT THE EARLY STAGE TUMORS. THE ACCURATE PERFORMANCE OF THIS MARKER WAS FURTHER REPLICATED IN AN INDEPENDENT SET OF PANCREATIC CANCER AND CONTROL SAMPLES (N = 78). THESE FINDINGS SUPPORT THE CANDIDATURE OF GHSR METHYLATION AS A HIGHLY ACCURATE PAN-CANCER MARKER. 2015 7 4242 30 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 8 977 34 CHRONIC ORAL EXPOSURE TO INORGANIC ARSENATE INTERFERES WITH METHYLATION STATUS OF P16INK4A AND RASSF1A AND INDUCES LUNG CANCER IN A/J MICE. ALTHOUGH INORGANIC ARSENATE (IAS(V)) OR ARSENITE (IAS(III)) IS CLEARLY A HUMAN CARCINOGEN, IT HAS BEEN DIFFICULT TO PRODUCE TUMORS IN RODENTS. IN THE PRESENT STUDY, WE ORALLY ADMINISTERED IAS(V) TO A/J MICE TO EXAMINE ARSENIC CARCINOGENICITY IN RODENT. A/J MICE (MALE, N = 120) ASSIGNED TO FOUR GROUPS WERE GIVEN DRINKING WATER CONTAINING 0, 1, 10, AND 100 PPM IAS(V) FOR 18 MONTHS. AT THE END OF EXPERIMENT, THE COMPLETE LUNGS WERE REMOVED AND USED FOR EXAMINING HISTOPATHOLOGY AND EXTRACTING RNA AND DNA. EPIGENETIC EFFECTS OF IAS(V) ON DNA METHYLATION PATTERNS OF P16INK4A AND RASSF1A GENES WERE DETERMINED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. CHANGES OF P16INK4A AND RASSF1A AT MRNA AND PROTEIN LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION AND IMMUNOHISTOCHEMISTRY. ARSENIC WAS ACCUMULATED DOSE DEPENDENTLY IN THE LUNG TISSUES OF IAS(V)-EXPOSED MICE. INCREASE IN LUNG TUMOR NUMBER AND LUNG TUMOR SIZE WAS OBSERVED IN IAS(V)-EXPOSED MICE COMPARED TO THE CONTROL. HISTOPATHOLOGICAL EXAMINATION SHOWED THAT THE RATE OF POORLY DIFFERENTIATED LUNG ADENOCARCINOMA WAS MUCH HIGHER IN IAS(V)-EXPOSED MICE THAN IN THE CONTROL. METHYLATION RATES APPEARED TO BE HIGHER IN A DOSE-RELATED TENDENCY IN LUNG TUMORS FROM IAS(V)-EXPOSED MICE COMPARED TO THE CONTROL. LOWER OR LOSS OF P16INK4A AND RASSF1A EXPRESSION WAS FOUND IN LUNG TUMORS FROM IAS(V)-EXPOSED MICE, COMPARED TO THAT IN NONTUMOR LUNG TISSUES FROM BOTH CONTROL AND IAS(V)-EXPOSED MICE, AND THIS REDUCED OR LOST EXPRESSION WAS IN ACCORDANCE WITH HYPERMETHYLATION OF THE GENES. IN CONCLUSION, IAS(V) EXPOSURE INCREASED LUNG TUMOR INCIDENCE AND MULTIPLICITY IN A/J MICE. EPIGENETIC CHANGES OF TUMOR SUPPRESSOR GENES SUCH AS P16INK4A AND RASSF1A ARE INVOLVED IN THE IAS(V)-INDUCED LUNG CARCINOGENESIS. 2006 9 1529 33 DNA METHYLATION CHANGES IN WHOLE BLOOD AND CD16+ NEUTROPHILS IN RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION IN WOMEN OF CHILDBEARING AGE. FOLATE, A WATER-SOLUBLE VITAMIN, IS A KEY SOURCE OF ONE-CARBON GROUPS FOR DNA METHYLATION, BUT STUDIES OF THE DNA METHYLATION RESPONSE TO SUPPLEMENTAL FOLIC ACID YIELD INCONSISTENT RESULTS. THESE STUDIES ARE COMMONLY CONDUCTED USING WHOLE BLOOD, WHICH CONTAINS A MIXED POPULATION OF WHITE BLOOD CELLS THAT HAVE BEEN SHOWN TO CONFOUND RESULTS. THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE IF CD16+ NEUTROPHILS MAY PROVIDE MORE SPECIFIC DATA THAN WHOLE BLOOD FOR IDENTIFYING DNA METHYLATION RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION. THE STUDY WAS PERFORMED IN NORMAL WEIGHT (BMI 18.5 - 24.9 KG/M2) WOMEN (18 - 35 Y; N = 12), WITH BLOOD SAMPLES TAKEN BEFORE AND AFTER 8 WEEKS OF FOLIC ACID SUPPLEMENTATION AT 800 MUG/DAY. DNA METHYLATION PATTERNS FROM WHOLE BLOOD AND ISOLATED CD16+ NEUTROPHILS WERE MEASURED ACROSS >485,000 CPG SITES THROUGHOUT THE GENOME USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP. OVER THE COURSE OF THE 8-WEEK SUPPLEMENTATION, 6746 AND 7513 CPG SITES CHANGED (P < 0.05) IN WHOLE BLOOD AND CD16+ NEUTROPHILS, RESPECTIVELY. DNA METHYLATION DECREASED IN 68.4% (WHOLE BLOOD) AND 71.8% (CD16+ NEUTROPHILS) OF THESE SITES. THERE WERE ONLY 182 CPG SITES THAT CHANGED IN BOTH THE WHOLE BLOOD AND CD16+ NEUTROPHILS, 139 OF WHICH CHANGED IN THE SAME DIRECTION. THESE RESULTS SUGGEST THAT THE GENOME-WIDE DNA METHYLATION RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION IS DIFFERENT BETWEEN WHOLE BLOOD AND CD16+ NEUTROPHILS AND THAT A SINGLE WHITE BLOOD CELL TYPE MAY FUNCTION AS A MORE SPECIFIC EPIGENETIC REPORTER OF FOLATE STATUS THAN WHOLE BLOOD. 2017 10 489 34 ASSESSING POTENTIAL MECHANISMS OF ARSENIC-INDUCED SKIN LESIONS AND CANCERS: HUMAN AND IN VITRO EVIDENCE. ENVIRONMENTAL EXPOSURE TO ARSENIC IS A MAJOR PUBLIC HEALTH CHALLENGE WORLDWIDE. IN DETAILING THE HALLMARK SIGNS OF CHRONIC ARSENIC EXPOSURE, PREVIOUS STUDIES HAVE SHOWN THAT EPIGENETIC AND IMMUNE DYSFUNCTION ARE ASSOCIATED WITH ARSENIC-INDUCED SKIN LESIONS; HOWEVER, KNOWLEDGE REGARDING INTERACTIONS BETWEEN THE MECHANISMS LISTED ABOVE IS LIMITED. IN THIS STUDY, A TOTAL OF 106 SKIN SAMPLES WERE COLLECTED OVER THE PAST 20 YEARS. BASED ON THE PRESENCE OR ABSENCE OF HIGH ARSENIC EXPOSURE, THE PARTICIPANTS WERE DIVIDED INTO ARSENIC EXPOSURE (72) AND REFERENCE (34) GROUPS. ADDITIONALLY, THE ARSENIC EXPOSURE GROUP WAS FURTHER DIVIDED INTO THE NON-CANCER GROUP (31, INCLUDING SKIN HYPERPIGMENTATION AND HYPERKERATOSIS) AND THE SKIN CANCER GROUP (41, INCLUDING BOWEN'S DISEASE, BASAL CELL CARCINOMA AND SQUAMOUS CELL CARCINOMA) ACCORDING TO A SKIN HISTOPATHOLOGICAL EXAMINATION. FIRST, THE ASSOCIATIONS AMONG MIR-155, NF-AT1 WITH IMMUNOLOGICAL DYSFUNCTION AND ARSENIC-INDUCED SKIN LESIONS AND CARCINOGENESIS WERE CONFIRMED USING THESE SKIN SAMPLES. IN THE ARSENIC-EXPOSED GROUP, MIR-155-5P, KERATIN 1(KRT1), KERATIN 10 (KRT10), AND KERATIN 6C (KRT6C) WERE SIGNIFICANTLY INCREASED IN THE SKIN (P < 0.05), WHILE NF-AT1, INTERLEUKIN-2 (IL-2), AND INTERFERON-GAMMA (IFN-GAMMA) WERE SIGNIFICANTLY DECREASED (P < 0.05). CLEAR CORRELATIONS WERE OBSERVED AMONG THESE FACTORS (P < 0.05). IN IMMORTALIZED HUMAN KERATINOCYTES, SILENCING AND OVEREXPRESSION OF NF-AT1 COULD ALTER THE EXPRESSION AND SECRETION OF IMMUNOLOGICAL DYSFUNCTION INDICATORS (IL-2 AND IFN-GAMMA) THAT ARE INDUCED BY ARSENIC EXPOSURE (P < 0.05); HOWEVER, MIR-155-5P LEVELS DID NOT CHANGE SIGNIFICANTLY (P > 0.05). THE MIR-155-5P MIMIC AND INHIBITOR COULD REGULATE THE NF-AT1-MEDIATED IMMUNOLOGICAL DYSFUNCTION CAUSED BY ARSENIC (P < 0.05). OUR STUDY PROVIDES SOME LIMITED EVIDENCE THAT MIR-155-5P REGULATES THE NF-AT1-MEDIATED IMMUNOLOGICAL DYSFUNCTION THAT IS INVOLVED IN THE PATHOGENESIS AND CARCINOGENESIS OF ARSENIC. THE SECOND MAJOR FINDING WAS THAT KRT1 AND KRT10 ARE MARKERS OF HYPERKERATOSIS CAUSED BY ARSENIC, AND KRT6C IS A POTENTIAL BIOMARKER THAT CAN REFLECT ARSENIC CARCINOGENESIS. 2020 11 2037 40 EPIGENETIC CHANGES OF TIMP-3, GSTP-1 AND 14-3-3 SIGMA GENES AS INDICATION OF STATUS OF CHRONIC INFLAMMATION AND CANCER. OBJECTIVES: THIS STUDY AIMED TO COMPARE THE EPIGENETIC CHANGES VIA HYPERMETHYLATION STATUS OF TIMP-3, GSTP-1 AND 14-3-3SIGMA GENES, BETWEEN HEALTHY SUBJECTS AND PATIENTS WITH REVERSIBLE CHRONIC INFLAMMATORY DISEASE, AND BETWEEN HEALTHY SUBJECTS AND PATIENTS WITH IRREVERSIBLE MALIGNANT DISEASE, TO HIGHLIGHT THE GENETIC CHANGES THAT OCCUR IN THE PROGRESSION FROM AN INFLAMMATORY CONDITION TO IRREVERSIBLE GENETIC CHANGES COMMONLY OBSERVED IN CANCER PATIENTS. METHODS: DNA WAS EXTRACTED FROM THE BLOOD OF 680 HEALTHY SUBJECTS, AND TISSUES AND BLOOD OF 110 PATIENTS WITH CHRONIC INFLAMMATION DISEASE OF THE GUMS, AS WELL AS NEOPLASTIC TISSUES OF 108 BREAST CANCER PATIENTS. METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) FOR TIMP-3, GSTP-1 AND 14-3-3SIGMA WAS PERFORMED, AND HYPERMETHYLATION STATUS WAS ANALYZED AND COMPARED BETWEEN THE 3 GROUPS. RESULTS: THE HYPERMETHYLATION FREQUENCIES OF TIMP-3 AND GSTP-1 OF REVERSIBLE CHRONIC INFLAMMATORY GUM DISEASE AND THE CONTROL GROUP WERE SIMILAR, BUT BOTH WERE SIGNIFICANTLY LOWER THAN THOSE FOR MALIGNANT DISEASE PATIENTS (P<0.0001). THE METHYLATION FREQUENCY OF 14-3-3SIGMA IN CHRONIC INFLAMMATORY GUM DISEASE WAS HIGHER THAN IN THE CANCER AND CONTROL GROUPS (P<0.0001). THE METHYLATION OF CPG ISLANDS IN TIMP-3 AND GSTP-1 IN CHRONIC INFLAMMATION PATIENTS OCCURRED AS FREQUENTLY AS IN THE CONTROL GROUP, BUT LESS FREQUENTLY THAN IN BREAST CANCER PATIENTS. HOWEVER, THE EPIGENETIC SILENCING OF 14-3-3SIGMA OCCURRED MORE FREQUENTLY IN THE CHRONIC INFLAMMATION GROUP THAN IN CANCER PATIENTS AND HEALTHY CONTROLS. CONCLUSIONS: THE EPIGENETIC SILENCING OF 14-3-3SIGMA MIGHT BE ESSENTIAL FOR CHRONIC INFLAMMATORY GUM DISEASE. THE EPIGENETIC CHANGES PRESENTED IN CHRONIC INFLAMMATION PATIENTS MIGHT DEMONSTRATE AN IRREVERSIBLE DESTRUCTION IN THE TISSUES OR ORGANS SIMILAR TO CANCER. 2014 12 2967 35 GENETIC AND EPIGENETIC REGULATION OF CATECHOL-O-METHYLTRANSFERASE IN RELATION TO INFLAMMATION IN CHRONIC FATIGUE SYNDROME AND FIBROMYALGIA. BACKGROUND: CATECHOL-O-METHYLTRANSFERASE (COMT) HAS BEEN SHOWN TO INFLUENCE CLINICAL PAIN, DESCENDING MODULATION, AND EXERCISE-INDUCED SYMPTOM WORSENING. COMT REGULATES NOCICEPTIVE PROCESSING AND INFLAMMATION, KEY PATHOPHYSIOLOGICAL FEATURES OF CHRONIC FATIGUE SYNDROME AND FIBROMYALGIA (CFS/FM). WE AIMED TO DETERMINE THE INTERACTIONS BETWEEN GENETIC AND EPIGENETIC MECHANISMS REGULATING COMT AND ITS INFLUENCE ON INFLAMMATORY MARKERS AND SYMPTOMS IN PATIENTS WITH CFS/FM. METHODS: A CASE-CONTROL STUDY WITH REPEATED-MEASURES DESIGN WAS USED TO REDUCE THE CHANCE OF FALSE POSITIVE AND INCREASE THE POWER OF OUR FINDINGS. FIFTY-FOUR PARTICIPANTS (28 PATIENTS WITH CFS/FM AND 26 CONTROLS) WERE ASSESSED TWICE WITHIN 4 DAYS. THE ASSESSMENT INCLUDED CLINICAL QUESTIONNAIRES, NEUROPHYSIOLOGICAL ASSESSMENT (PAIN THRESHOLDS, TEMPORAL SUMMATION, AND CONDITIONED PAIN MODULATION), AND BLOOD WITHDRAWAL IN ORDER TO ASSESS RS4818, RS4633, AND RS4680 COMT POLYMORPHISMS AND PERFORM HAPLOTYPE ESTIMATION, DNA METHYLATION IN THE COMT GENE (BOTH MB-COMT AND S-COMT PROMOTERS), AND CYTOKINE EXPRESSION (TNF-ALPHA, IFN-GAMMA, IL-6, AND TGF-BETA). RESULTS: COMT HAPLOTYPES WERE ASSOCIATED WITH DNA METHYLATION IN THE S-COMT PROMOTER, TGF-BETA EXPRESSION, AND SYMPTOMS. HOWEVER, THIS WAS NOT SPECIFIC FOR ONE CONDITION. SIGNIFICANT BETWEEN-GROUP DIFFERENCES WERE FOUND FOR INCREASED DNA METHYLATION IN THE MB-COMT PROMOTER AND DECREASED IFN-GAMMA EXPRESSION IN PATIENTS. DISCUSSION: OUR RESULTS ARE CONSISTENT WITH BASIC AND CLINICAL RESEARCH, PROVIDING INTERESTING INSIGHTS INTO GENETIC-EPIGENETIC REGULATORY MECHANISMS. MB-COMT DNA METHYLATION MIGHT BE AN INDEPENDENT FACTOR CONTRIBUTING TO THE PATHOPHYSIOLOGY OF CFS/FM. FURTHER RESEARCH ON DNA METHYLATION IN COMPLEX CONDITIONS SUCH AS CFS/FM IS WARRANTED. WE RECOMMEND FUTURE RESEARCH TO EMPLOY A REPEATED-MEASURE DESIGN TO CONTROL FOR BIOMARKERS VARIABILITY AND WITHIN-SUBJECT CHANGES. 2022 13 5841 33 STRUCTURAL CHROMATIN ALTERATIONS IN PERIPHERAL BLOOD LEUKOCYTES OF ALCOHOL-DEPENDENT INDIVIDUALS DURING DETOXIFICATION THERAPY. BACKGROUND/AIM: THE AIM OF THIS STUDY WAS TO INVESTIGATE THE STATE OF CHROMATIN CONDENSATION IN PERIPHERAL BLOOD LEUKOCYTES OF ALCOHOLICS, DURING THE EARLY DETOXIFICATION PERIOD, IN ORDER TO HIGHLIGHT STRUCTURAL MODIFICATIONS, INDICATING EPIGENETIC MECHANISMS REGULATED BY ALCOHOL. MATERIALS AND METHODS: BLOOD SAMPLES WERE OBTAINED FROM ALCOHOLIC PATIENTS, WHO WERE ADMITTED FOR DETOXIFICATION ON AN INPATIENT BASIS, AND FROM HEALTHY CONTROLS. THE LEVEL OF CONDENSED HETEROCHROMATIN AND DE-CONDENSED EUCHROMATIN WERE DETECTED THROUGH THE RATIO OF LYSINE TO ARGININE RESIDUES, BY THE APPLICATION OF THE AMMONIACAL SILVER REACTION (ASR) STAINING ON LEUKOCYTE PELLETS, AND THROUGH IMMUNOHISTOCHEMICAL LOCALIZATION OF HISTONE H1 ON PERIPHERAL BLOOD SMEARS. RESULTS: LYMPHOCYTES AND NEUTROPHILS WITH RELAXED DE-CONDENSED CHROMATIN WERE FOUND, INDICATING A MORE REACTIVE GENOME IN ALCOHOLICS, EVEN AT THE STAGE OF DETOXIFICATION. CONCLUSION: THE RESULTS UNDERLINE THE IMPORTANCE OF CHROMATIN STRUCTURE OF LEUKOCYTES AS A SENSITIVE, PERIPHERAL, BIOLOGICAL MARKER FOR EPIGENETIC STUDIES IN LIVING CHRONIC ALCOHOLICS. 2014 14 6488 44 TP53 R72P POLYMORPHISM MODULATES DNA METHYLATION IN HEPATOCELLULAR CARCINOMA. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC) IS CHARACTERIZED BY WIDESPREAD EPIDEMIOLOGICAL AND MOLECULAR HETEROGENEITY. PREVIOUS WORK SHOWED THAT IN THE WESTERN PART OF NORTH AFRICA, A REGION OF LOW INCIDENCE OF HCC, MUTATIONS ARE SCARCE FOR THIS TUMOR TYPE. AS EPIGENETIC CHANGES ARE CONSIDERED POSSIBLE SURROGATES TO MUTATIONS IN HUMAN CANCERS, WE DECIDED, THUS, TO CHARACTERIZE DNA METHYLATION IN HCC FROM NORTH-AFRICAN PATIENTS. METHODS: A SET OF 11 LOCI WAS INVESTIGATED IN A SERIES OF 45 TUMOR SPECIMENS USING METHYLATION-SPECIFIC AND COMBINED-BISULFITE RESTRICTION ASSAY PCR. RESULTS OBTAINED ON CLINICAL SAMPLES WERE SUBSEQUENTLY VALIDATED IN LIVER CANCER CELL LINES. RESULTS: DNA METHYLATION AT TUMOR SUPPRESSOR LOCI IS SIGNIFICANTLY HIGHER IN SAMPLES DISPLAYING CHROMOSOME INSTABILITY. MORE IMPORTANTLY, DNA METHYLATION WAS SIGNIFICANTLY HIGHER IN ARG/ARG WHEN COMPARED TO PRO/PRO GENOTYPE CARRIERS AT CODON 72 RS1042522 OF TP53 (65% VS 20% METHYLATED LOCI, P = 0.0006), A POLYMORPHISM ALREADY KNOWN TO AFFECT SOMATIC MUTATION RATE IN HUMAN CARCINOMAS. IN VITRO EXPERIMENTS IN CELL LINES INDICATED THAT ENZYMES CONTROLLING DNA METHYLATION WERE DIFFERENTIALLY REGULATED BY CODON 72 ARG OR PRO ISOFORMS OF P53. FURTHERMORE, THE ARG72-CARRYING VERSION OF P53 WAS SHOWN TO RE-METHYLATE DNA MORE RAPIDLY THAN THE PRO-HARBORING ISOFORM. FINALLY, PRO-CARRYING CELL LINES WERE SHOWN TO BE SIGNIFICANTLY MORE RESISTANT TO DECITABINE TREATMENT (TWO-FOLD, P = 0.005). CONCLUSIONS: OUR DATA SUGGEST THAT ARG72PRO POLYMORPHISM IN A WT P53 CONTEXT MAY ACT AS A PRIMARY DRIVER OF EPIGENETIC CHANGES IN HCC. IT SUGGESTS, IN ADDITION, THAT RS1042522 GENOTYPE MAY PREDICT SENSITIVITY TO EPIGENETIC-TARGETED THERAPY. THIS MODEL OF LIVER TUMORIGENESIS THAT ASSOCIATES LOW PENETRANCE GENETIC PREDISPOSITION TO EPIGENETIC CHANGES EMERGES FROM A REGION OF LOW HCC INCIDENCE AND IT MAY, THEREFORE, APPLY ESSENTIALLY TO POPULATION LIVING IN SIMILAR AREAS. SURVEYS ON POPULATIONS SUBMITTED TO HIGHLY MUTAGENIC CONDITIONS AS PERINATALLY-ACQUIRED CHRONIC HEPATITIS B OR AFLATOXIN B1 EXPOSURE REMAINED TO BE CONDUCTED TO VALIDATE OUR OBSERVATIONS AS A GENERAL MODEL. 2015 15 546 41 ATTENUATED EXPRESSION OF SLCO2A1 CAUSED BY DNA METHYLATION IN PEDIATRIC INFLAMMATORY BOWEL DISEASE. BACKGROUND: SLCO2A1 ENCODES A PROSTAGLANDIN (PG) TRANSPORTER, AND AUTOSOMAL RECESSIVE PATHOGENIC VARIANTS OF THIS GENE CAUSE CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1. IT IS UNCLEAR WHETHER A HETEROZYGOUS PATHOGENIC VARIANT OF SLCO2A1 HAS A ROLE IN THE PATHOGENESIS OF OTHER TYPES OF INFLAMMATORY BOWEL DISEASE (IBD). IN THIS STUDY, WE INVESTIGATED THE POSSIBLE INVOLVEMENT OF A LOCAL EPIGENETIC ALTERATION IN SLCO2A1 IN PATIENTS WITH A HETEROZYGOUS PATHOGENIC VARIANT. METHODS: WE CONDUCTED WHOLE-EXOME SEQUENCING OF SAMPLES FROM 2 SISTERS WITH SUSPECTED MONOGENIC IBD. IN ADDITION, WE PERFORMED BISULFITE SEQUENCING USING DNA EXTRACTED FROM THEIR SMALL AND LARGE INTESTINE SAMPLES TO EXPLORE EPIGENETIC ALTERATIONS. RESULTS: A HETEROZYGOUS SPLICING SITE VARIANT, SLCO2A1:C.940 + 1G > A, WAS DETECTED IN BOTH PATIENTS. TO EXPLORE THE POSSIBLE INVOLVEMENT OF EPIGENETIC ALTERATIONS, WE ANALYZED PROTEIN AND MESSENGER RNA EXPRESSION OF SLCO2A1, AND OBSERVED ATTENUATED SLCO2A1 EXPRESSION IN THE INFLAMED LESIONS OF THESE PATIENTS COMPARED WITH THAT IN THE CONTROL INDIVIDUALS. FURTHERMORE, BISULFITE SEQUENCING INDICATED DENSE METHYLATION IN THE PROMOTER REGION OF SLCO2A1 ONLY IN THE INFLAMED LESIONS OF BOTH PATIENTS. THE URINARY PG METABOLITE LEVELS IN THESE PATIENTS WERE COMPARABLE TO THOSE IN PATIENTS WITH CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1 AND HIGHER THAN THOSE IN THE CONTROL INDIVIDUALS. WE FOUND CONSIDERABLY HIGHER LEVELS OF THE METABOLITES IN PATIENT 1, WHO SHOWED MORE SEVERE SYMPTOMS THAN PATIENT 2. CONCLUSIONS: LOCAL DNA METHYLATION ATTENUATED SLCO2A1 EXPRESSION, WHICH MAY EVOKE LOCAL INFLAMMATION OF THE MUCOSA BY THE UNINCORPORATED PG. THESE FINDINGS MAY IMPROVE OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS UNDERLYING IBD DEVELOPMENT. 2023 16 5273 41 PROMOTER METHYLATION AND BDNF AND DAT1 GENE EXPRESSION PROFILES IN PATIENTS WITH DRUG ADDICTION. BACKGROUND: DRUG ADDICTION IS A BRAIN DISORDER THAT HAS NEGATIVE CONSEQUENCES FOR INDIVIDUALS AND SOCIETY. ADDICTIONS ARE CHRONIC RELAPSING DISEASES OF THE BRAIN THAT ARE CAUSED BY DIRECT DRUG-INDUCED EFFECTS AND PERSEVERING NEUROADAPTATIONS AT THE EPIGENETIC, NEUROPEPTIDE AND NEUROTRANSMITTER LEVELS. BECAUSE THE DOPAMINERGIC SYSTEM HAS A SIGNIFICANT ROLE IN DRUG ABUSE, THE PURPOSE OF THIS STUDY WAS TO ANALYZE THE METHYLATION AND EXPRESSION PROFILE OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) AND DOPAMINE TRANSPORTER (DAT1) GENES IN INDIVIDUALS WITH DRUG ADDICTION. MATERIALS AND METHODS: BDNF AND DAT1 PROMOTER METHYLATION WERE INVESTIGATED WITH A METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) TECHNIQUE IN BLOOD SAMPLES FROM 75 INDIVIDUALS WITH DRUG ADDICTION AND 65 HEALTHY CONTROLS. THE EXPRESSION LEVELS OF BDNF AND DAT1 WERE ASSESSED IN 12 MRNA SAMPLES FROM THE BLOOD OF PATIENTS AND COMPARED TO THE SAMPLES OF HEALTHY CONTROLS (N = 12) WITH REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION PCR. RESULTS: NO SIGNIFICANT DIFFERENCES WERE FOUND IN THE METHYLATION OF BDNF AND DAT1 BETWEEN PATIENTS AND CONTROLS, BUT THE RELATIVE LEVELS OF EXPRESSION OF BDNF AND DAT1 MRNA DIFFERED SIGNIFICANTLY IN THE PATIENTS COMPARED TO CONTROLS (P < 0.0001). CONCLUSION: THESE RESULTS SHOWED THAT THE METHYLATION STATUS OF THE BDNF AND DAT1 GENES HAD NO SIGNIFICANT FUNCTION IN THE PROCESSES OF DRUG ADDICTION. 2015 17 6190 42 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 18 1729 29 DYSREGULATION OF MIR-155 EXPRESSION IN PROFESSIONAL MIXED MARTIAL ARTS (MMA) FIGHTERS. PSYCHOLOGICAL AND PHYSICAL STRESS CAN INDUCE DYSREGULATION OF GENE EXPRESSION VIA CHANGES IN DNA METHYLATION AND MICRORNA (MIRNA) EXPRESSION. SUCH EPIGENETIC MODIFICATIONS ARE YET TO BE INVESTIGATED IN PROFESSIONAL MIXED MARTIAL ARTS (MMA) FIGHTERS SUBJECT TO HIGHLY STRESSFUL TRAINING INVOLVING REPETITIVE HEAD IMPACTS. THIS STUDY EXAMINED DIFFERENCES IN DNA METHYLATION AND MIRNA EXPRESSION IN ELITE MMA FIGHTERS COMPARED TO ACTIVE CONTROLS. GLOBAL METHYLATION DIFFERENCES BETWEEN GROUPS WERE ASSESSED VIA A LINE-1 ASSAY. AT THE SAME TIME, PCR ARRAYS WERE USED TO ESTIMATE DIFFERENTIAL EXPRESSION IN SAMPLES OF 21 FIGHTERS AND 15 CONTROLS FOR 192 DIFFERENT MIRNAS ASSOCIATED WITH INFLAMMATORY DISEASES. AN INDEPENDENT-SAMPLES T-TEST FOUND NO SIGNIFICANT DIFFERENCE IN LINE-1 METHYLATION BETWEEN GROUPS. HOWEVER, AN INDEPENDENT-SAMPLES MANN-WHITNEY U TEST REVEALED A SIGNIFICANT UPREGULATION IN THE EXPRESSION OF MIR-155 IN MMA FIGHTER PLASMA. SINCE MIR-155 HAS BEEN RECOGNIZED AS AN IMPORTANT REGULATOR OF NEUROINFLAMMATION, THIS DYSREGULATION SUGGESTS A POSSIBLE EPIGENETIC MECHANISM RESPONSIBLE FOR CHRONIC INFLAMMATION ASSOCIATED WITH PROFESSIONAL-LEVEL MMA TRAINING. CONSISTENT WITH OTHER PUBLISHED WORKS, THIS STUDY HIGHLIGHTS THE POTENTIAL OF MIR-155 NOT ONLY AS A BIOMARKER FOR MONITORING LONG-TERM HEALTH RISKS LINKED TO HEAD TRAUMA BUT ALSO AS A TARGET TO REMEDIATE THE IMPACT OF CHRONIC NEUROINFLAMMATION. 2023 19 1264 42 CYP2E1 EPIGENETIC REGULATION IN CHRONIC, LOW-LEVEL TOLUENE EXPOSURE: RELATIONSHIP WITH OXIDATIVE STRESS AND SMOKING HABIT. BACKGROUND: CYP2E1 IS A VERSATILE PHASE I DRUG-METABOLIZING ENZYME RESPONSIBLE FOR THE BIOTRANSFORMATION OF MOST VOLATILE ORGANIC COMPOUNDS, INCLUDING TOLUENE. HUMAN TOLUENE EXPOSURE INCREASES CYP2E1 MRNA AND MODIFIES ITS ACTIVITY IN LEUCOCYTES; HOWEVER, EPIGENETIC IMPLICATIONS OF THIS INTERACTION HAVE NOT BEEN INVESTIGATED. GOAL: TO DETERMINE PROMOTER METHYLATION OF CYP2E1 AND OTHER GENES KNOWN TO BE AFFECTED BY TOLUENE EXPOSURE. METHODS: WE OBTAINED VENOUS BLOOD FROM 24 TANNERY WORKERS EXPOSED TO TOLUENE (MEAN LEVELS: 10.86+/-7MG/M(3)) AND 24 ADMINISTRATIVE WORKERS (REFERENCE GROUP, MEAN LEVELS 0.21+/-0.02MG/M(3)) ALL OF THEM FROM THE CITY OF LEON, GUANAJUATO, MEXICO. AFTER DNA EXTRACTION AND BISULFITE TREATMENT, WE PERFORMED PCR-PYROSEQUENCING IN ORDER TO MEASURE METHYLATION LEVELS AT PROMOTER REGION OF 13 GENES. RESULTS: IN EXPOSED GROUP WE FOUND SIGNIFICANT CORRELATIONS BETWEEN TOLUENE AIRBORNE LEVELS AND CYP2E1 PROMOTER METHYLATION (R=-.36, P<0.05), AS WELL AS FOR IL6 PROMOTER METHYLATION LEVELS (R=.44, P<0.05). MOREOVER, CYP2E1 PROMOTER METHYLATION LEVELS WHERE HIGHER IN TOLUENE-EXPOSED SMOKERS COMPARED TO NONSMOKERS (P=0.009). WE ALSO OBSERVED SIGNIFICANT CORRELATIONS FOR CYP2E1 PROMOTER METHYLATION WITH GSTP1 AND SOD1 PROMOTER METHYLATION LEVELS (R=-.37, P<0.05 AND R=-.34, P<0.05 RESPECTIVELY). CONCLUSION: THESE RESULTS HIGHLIGHT THE IMPORTANCE OF CONSIDERING CYP2E1 EPIGENETIC MODIFICATIONS, AS WELL AS ITS INTERACTIONS WITH OTHER GENES, AS KEY FACTORS FOR UNRAVELING THE SUB CELLULAR MECHANISMS OF TOXICITY EXERTED BY OXIDATIVE STRESS, WHICH CAN INITIATE DISEASE PROCESS IN CHRONIC, LOW-LEVEL TOLUENE EXPOSURE. PEOPLE CO-EXPOSED TO TOLUENE AND TOBACCO SMOKE ARE IN HIGHER RISK DUE TO A POSSIBLE CYP2E1 REPRESSION. 2015 20 3991 34 LONGITUDINAL EFFECTS OF DEVELOPMENTAL BISPHENOL A, VARIABLE DIET, AND PHYSICAL ACTIVITY ON AGE-RELATED METHYLATION IN BLOOD. RESEARCH INDICATES THAT ENVIRONMENTAL FACTORS CAN ALTER DNA METHYLATION, BUT THE SPECIFIC EFFECTS OF ENVIRONMENTAL EXPOSURES ON EPIGENETIC AGING REMAIN UNCLEAR. HERE, USING A MOUSE MODEL OF HUMAN-RELEVANT EXPOSURES, WE TESTED THE HYPOTHESIS THAT EARLY-LIFE EXPOSURE TO BISPHENOL A (BPA), VARIABLE DIET, AND/OR CHANGES IN PHYSICAL ACTIVITY WOULD MODIFY RATES OF AGE-RELATED METHYLATION AT SEVERAL TARGET REGIONS, AS MEASURED FROM LONGITUDINAL BLOOD SAMPLES (2, 4, AND 10 MONTHS OLD). DNA METHYLATION WAS QUANTIFIED AT TWO REPETITIVE ELEMENTS (LINE-1, IAP), TWO IMPRINTED GENES (IGF2, H19), AND ONE NON-IMPRINTED GENE (ESR1) IN ISOGENIC MICE DEVELOPMENTALLY EXPOSED TO CONTROL, CONTROL + BPA (50 MICROG/KG DIET), WESTERN HIGH-FAT DIET (WHFD), OR WESTERN + BPA DIETS. IN BLOOD SAMPLES, ESR1 DNA METHYLATION INCREASED SIGNIFICANTLY WITH AGE, BUT NO OTHER INVESTIGATED LOCI SHOWED SIGNIFICANT AGE-RELATED METHYLATION. LINE-1 AND IAP BOTH SHOWED SIGNIFICANT NEGATIVE ENVIRONMENTAL DEFLECTION BY WHFD EXPOSURE (P < 0.05). ESR1ALSO SHOWED SIGNIFICANT NEGATIVE ENVIRONMENTAL DEFLECTION BY WHFD EXPOSURE IN FEMALE MICE (P = 0.02), BUT NOT MALE MICE. PHYSICAL ACTIVITY HAD A NON-SIGNIFICANT POSITIVE EFFECT ON AGE-RELATED ESR1 METHYLATION IN FEMALE BLOOD, SUGGESTING THAT IT MAY PARTIALLY ABROGATE THE EFFECTS OF WHFD ON THE AGING EPIGENOME. THESE RESULTS SUGGEST THAT DEVELOPMENTAL NUTRITIONAL EXPOSURES CAN MODIFY AGE-RELATED DNA METHYLATION PATTERNS AT A GENE RELATED TO GROWTH AND DEVELOPMENT. AS SUCH, ENVIRONMENTAL DEFLECTION OF THE AGING EPIGENOME MAY HELP TO EXPLAIN THE GROWING PREVALENCE OF CHRONIC DISEASES IN HUMAN POPULATIONS. 2018