1 5683 147 SHORTER TELOMERE LENGTH IN PERIPHERAL BLOOD LYMPHOCYTES OF WORKERS EXPOSED TO POLYCYCLIC AROMATIC HYDROCARBONS. SHORTER TELOMERE LENGTH (TL) IN PERIPHERAL BLOOD LYMPHOCYTES (PBLS) IS PREDICTIVE OF LUNG CANCER RISK. POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) ARE ESTABLISHED LUNG CARCINOGENS THAT CAUSE CHROMOSOME INSTABILITY. WHETHER PAH EXPOSURE AND ITS MOLECULAR EFFECTS ARE LINKED WITH SHORTER TL HAS NEVER BEEN EVALUATED. IN THE PRESENT STUDY, WE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO PAHS ON TL MEASURED IN PBLS OF POLISH MALE NON-CURRENT SMOKING COKEOVEN WORKERS AND MATCHED CONTROLS. PAH EXPOSURE AND MOLECULAR EFFECTS WERE CHARACTERIZED USING MEASURES OF INTERNAL DOSE (URINARY 1-PYRENOL), EFFECTIVE DOSE [ANTI-BENZO[A]PYRENE DIOLEPOXIDE (ANTI-BPDE)-DNA ADDUCT], GENETIC INSTABILITY (MICRONUCLEI, MN) AND DNA METHYLATION [P53 PROMOTER AND ALU AND LONG INTERSPERSED NUCLEAR ELEMENT-1 (LINE-1) REPETITIVE ELEMENTS, AS SURROGATE MEASURES OF GLOBAL METHYLATION] IN PBLS. TL WAS MEASURED BY REAL-TIME POLYMERASE CHAIN REACTION. COKEOVEN WORKERS WERE HEAVILY EXPOSED TO PAHS (79% EXCEEDED THE URINARY 1-PYRENOL BIOLOGICAL EXPOSURE INDEX) AND EXHIBITED LOWER TL (P = 0.038) THAN CONTROLS, AS WELL AS HIGHER LEVELS OF GENETIC AND CHROMOSOMAL ALTERATIONS [I.E. ANTI-BPDE-DNA ADDUCT AND MN (P < 0.0001)] AND EPIGENETIC CHANGES [I.E. P53 GENE-SPECIFIC PROMOTER AND GLOBAL METHYLATION (P 3 MUMOL 1-PYRENOL/MOL CREATININE) SHOWED HIGHER MTDNACN [GEOMETRIC MEANS (GM) OF 1.06 (UNADJUSTED) AND 1.07 (AGE-ADJUSTED)] COMPARED WITH CONTROLS [GM 0.89 (UNADJUSTED); 0.89 (AGE-ADJUSTED); (P = 0.029 AND 0.016)], AS WELL AS HIGHER LEVELS OF GENETIC AND CHROMOSOMAL [I.E., ANTI-BPDE-DNA ADDUCTS (P < 0.001), MICRONUCLEI (P < 0.001), AND TELOMERE LENGTH (P = 0.053)] AND EPIGENETIC [I.E., P53 GENE-SPECIFIC PROMOTER METHYLATION (P < 0.001)] ALTERATIONS IN THE NDNA. IN THE WHOLE STUDY POPULATION, UNADJUSTED AND AGE-ADJUSTED MTDNACN WAS POSITIVELY CORRELATED WITH 1-PYRENOL (P = 0.043 AND 0.032) AND ANTI-BPDE-DNA ADDUCTS (P = 0.046 AND 0.049). CONCLUSIONS: PAH EXPOSURE AND PAH-RELATED NDNA GENOTOXICITY ARE ASSOCIATED WITH INCREASED MTDNACN. IMPACT: THE PRESENT STUDY IS SUGGESTIVE OF POTENTIAL ROLES OF MTDNACN IN PAH-INDUCED CARCINOGENESIS. 2013 3 5957 31 TELOMERE LENGTH AND EPIGENETIC AGE ACCELERATION IN ADOLESCENTS WITH ANXIETY DISORDERS. EVIDENCE ON THE RELATIONSHIP BETWEEN GENETICS AND MENTAL HEALTH ARE FLOURISHING. HOWEVER, FEW STUDIES ARE EVALUATING EARLY BIOMARKERS THAT MIGHT LINK GENES, ENVIRONMENT, AND PSYCHOPATHOLOGY. WE AIMED TO STUDY TELOMERE LENGTH (TL) AND EPIGENETIC AGE ACCELERATION (AA) IN A COHORT OF ADOLESCENTS WITH AND WITHOUT ANXIETY DISORDERS (N = 234). WE EVALUATED A REPRESENTATIVE SUBSAMPLE OF PARTICIPANTS AT BASELINE AND AFTER 5 YEARS (N = 76) AND CATEGORIZED THEM ACCORDING TO THEIR ANXIETY DISORDER DIAGNOSIS AT BOTH TIME POINTS: (1) CONTROL GROUP (NO ANXIETY DISORDER, N = 18), (2) VARIABLE GROUP (ANXIETY DISORDER IN ONE EVALUATION, N = 38), AND (3) PERSISTENT GROUP (ANXIETY DISORDER AT BOTH TIME POINTS, N = 20). WE ASSESSED RELATIVE MEAN TL BY REAL-TIME QUANTITATIVE PCR AND DNA METHYLATION BY INFINIUM HUMANMETHYLATION450 BEADCHIP. WE CALCULATED AA USING THE HORVATH AGE ESTIMATION ALGORITHM AND ANALYZED DIFFERENCES AMONG GROUPS USING GENERALIZED LINEAR MIXED MODELS. THE PERSISTENT GROUP OF ANXIETY DISORDER DID NOT CHANGE TL OVER TIME (P = 0.495). THE VARIABLE GROUP HAD HIGHER BASELINE TL (P = 0.003) BUT NO ACCELERATED TL EROSION IN COMPARISON TO THE NON-ANXIETY CONTROL GROUP (P = 0.053). FURTHERMORE, THERE WERE NO DIFFERENCES IN AA AMONG GROUPS OVER TIME. OUR FINDINGS SUGGEST THAT ADOLESCENTS WITH CHRONIC ANXIETY DID NOT CHANGE TELOMERE LENGTH OVER TIME, WHICH COULD BE RELATED TO A DELAY IN NEURONAL DEVELOPMENT IN THIS PERIOD OF LIFE. 2021 4 974 45 CHRONIC OCCUPATIONAL EXPOSURE ENDURED BY TOBACCO FARMERS FROM BRAZIL AND ASSOCIATION WITH DNA DAMAGE. TOBACCO FARMING IS AN IMPORTANT ECONOMIC INCOME IN BRAZIL, ALTHOUGH IT HAS BEEN CHALLENGED AS REGARD THE OCCUPATIONAL EXPOSURE TO BOTH PESTICIDES AND NICOTINE ENDURED BY FARMERS. CHRONIC OCCUPATIONAL EXPOSURE TO COMPLEX MIXTURES CAN LEAD TO HEALTH HAZARDOUS. WE EXAMINED GENOMIC INSTABILITY AND EPIGENETIC CHANGES IN TOBACCO FARMERS OCCUPATIONALLY EXPOSED TO PESTICIDE MIXTURES AND NICOTINE AT TOBACCO FIELDS. DNA DAMAGE WAS ASSESSED BY ALKALINE COMET ASSAY IN BLOOD CELLS. GENOMIC DNA WAS ISOLATED, AND TELOMERE LENGTH WAS MEASURED USING QUANTITATIVE POLYMERASE CHAIN REACTION ASSAY. WE MEASURED 5-METHYL-2'-DEOXYCYTIDINE, A MARKER OF GLOBAL DNA METHYLATION, AND P16 PROMOTER METHYLATION. THE OXIDATIVE PROFILE WAS EVALUATED BY TROLOX EQUIVALENT ANTIOXIDANT CAPACITY AND LIPID PEROXIDATION (THIOBARBITURIC ACID REACTIVE SUBSTANCES) IN SERUM. EXPOSURE PARAMETERS, PLASMA COTININE AND INORGANIC ELEMENT LEVELS, WERE ALSO MEASURED. DNA DAMAGE WAS SIGNIFICANTLY ELEVATED FOR FARMERS IN RELATION TO UNEXPOSED GROUP (P < 0.001; MANN-WHITNEY TEST) AND POSITIVELY ASSOCIATED WITH YEARS OF EXPOSURE. INVERSE RELATIONSHIP BETWEEN DNA DAMAGE AND TOTAL EQUIVALENT ANTIOXIDANT ACTIVITY WAS DEMONSTRATED FOR EXPOSED AND UNEXPOSED GROUPS. EXPOSED GROUP SHOWED SIGNIFICANTLY SHORTER TELOMERES (P < 0.001; UNPAIRED T-TEST) AND DNA HYPOMETHYLATION (P < 0.001; UNPAIRED T-TEST), AS WELL AS P16 HYPERMETHYLATION (P = 0.003; MANN-WHITNEY TEST). LIPID PEROXIDATION WAS INCREASED FOR EXPOSED GROUP IN RELATION TO UNEXPOSED ONE (P = 0.02; MANN-WHITNEY TEST) AND PRESENTED A POSITIVE CORRELATION WITH GLOBAL DNA METHYLATION (P = 0.0264). FARMERS HAVE INCREASED PLASMA COTININE LEVELS (P < 0.001) AND INORGANIC ELEMENTS (PHOSPHORUS, SULPHUR AND CHLORINE) IN RELATION TO UNEXPOSED GROUP. ELEVATED OXIDATIVE STRESS LEVELS DUE TO CHRONIC OCCUPATIONAL PESTICIDE MIXTURES AND NICOTINE EXPOSURE IN TOBACCO FARMERS WERE ASSOCIATED WITH HIGHER DNA DAMAGE, SHORTER TELOMERES AND ALTERED DNA METHYLATION. TELOMERE-ACCELERATED ATTRITION DUE TO EXPOSURE MAY BE POTENTIAL INTERMEDIATE STEP BEFORE A DISEASE STATE. 2018 5 5960 42 TELOMERE LENGTH IN HEPATOCELLULAR CARCINOMA AND PAIRED ADJACENT NON-TUMOR TISSUES BY QUANTITATIVE PCR. TELOMERE SHORTENING LIMITS THE PROLIFERATIVE CAPACITY OF HUMAN CELLS, RESTRAINS THE REGENERATIVE CAPACITY OF ORGAN SYSTEMS DURING CHRONIC DISEASES AND AGING AND ALSO INDUCES CHROMOSOMAL INSTABILITY AS WELL AS INITIATION OF CANCER. PREVIOUS STUDIES DEMONSTRATED THAT TELOMERES ARE OFTEN SIGNIFICANTLY SHORTER IN TUMOR TISSUE, INCLUDING HEPATOCELLULAR CARCINOMA (HCC), COMPARED TO THE SURROUNDING TISSUE, BUT TELOMERE LENGTH IN HCC TISSUES WAS NOT CORRELATED WITH SEVERAL CLINICAL PARAMETERS, SUCH AS AGE, SEX, HBV OR HCV INFECTIONS AND TUMOR SIZE. IN THE PRESENT STUDY, THE TELOMERE LENGTH RATIO OF 36 PAIRED HCC, AND THEIR ADJACENT NON-TUMOR TISSUES WAS MEASURED BY QUANTITATIVE PCR (Q-PCR). THE MEAN TELOMERE LENGTHS (SD) FOR HCC AND ADJACENT NON-TUMOR TISSUES WERE 0.26 (0.10) AND 0.47 (0.20) RESPECTIVELY (T = 6.22, P < 0.0001). THERE WAS A LARGE DIFFERENCE IN THE DISTRIBUTION OF SUBJECTS BASED ON TELOMERE LENGTH IN TUMOR AND ADJACENT NON-TUMOR TISSUES. THE NUMBER OF TUMORS WITH TELOMERE LENGTH SHORTER THAN 0.50 WAS MUCH HIGHER THAN THAT OF ADJACENT NON-TUMOR TISSUES; MORE THAN 90% OF THE TISSUES WITH TELOMERE LENGTH > OR = 0.50 WERE ADJACENT NON-TUMOR TISSUES. THE CORRELATIONS BETWEEN TELOMERE LENGTH AND AFLATOXIN B1- AND POLYCYCLIC AROMATIC HYDROCARBON-DNA ADDUCTS LEVEL, P53 MUTATIONS AND P16 HYPERMETHYLATION STATUS WERE ALSO TESTED, BUT NO SIGNIFICANT ASSOCIATIONS WERE FOUND. THE RELATIONSHIP BETWEEN TELOMERE LENGTH SHORTENING, CHEMICAL CARCINOGEN EXPOSURE, AND GENETIC AND EPIGENETIC CHANGES IN HEPATOCARCINOGENESIS NEEDS FURTHER INVESTIGATION. 2007 6 1497 29 DNA METHYLATION AGE IS ACCELERATED IN ALCOHOL DEPENDENCE. ALCOHOL DEPENDENCE (ALC) IS A CHRONIC, RELAPSING DISORDER THAT INCREASES THE BURDEN OF CHRONIC DISEASE AND SIGNIFICANTLY CONTRIBUTES TO NUMEROUS PREMATURE DEATHS EACH YEAR. PREVIOUS RESEARCH SUGGESTS THAT CHRONIC, HEAVY ALCOHOL CONSUMPTION IS ASSOCIATED WITH DIFFERENTIAL DNA METHYLATION PATTERNS. IN ADDITION, DNA METHYLATION LEVELS AT CERTAIN CPG SITES HAVE BEEN CORRELATED WITH AGE. WE USED AN EPIGENETIC CLOCK TO INVESTIGATE THE POTENTIAL ROLE OF EXCESSIVE ALCOHOL CONSUMPTION IN EPIGENETIC AGING. WE EXPLORED THIS QUESTION IN FIVE INDEPENDENT COHORTS, INCLUDING DNA METHYLATION DATA DERIVED FROM DATASETS FROM BLOOD (N = 129, N = 329), LIVER (N = 92, N = 49), AND POSTMORTEM PREFRONTAL CORTEX (N = 46). ONE BLOOD DATASET AND ONE LIVER TISSUE DATASET OF INDIVIDUALS WITH ALC EXHIBITED POSITIVE AGE ACCELERATION (P < 0.0001 AND P = 0.0069, RESPECTIVELY), WHEREAS THE OTHER BLOOD AND LIVER TISSUE DATASETS BOTH EXHIBITED TRENDS OF POSITIVE AGE ACCELERATION THAT WERE NOT SIGNIFICANT (P = 0.83 AND P = 0.57, RESPECTIVELY). PREFRONTAL CORTEX TISSUE EXHIBITED A TREND OF NEGATIVE AGE ACCELERATION (P = 0.19). THESE RESULTS SUGGEST THAT EXCESSIVE ALCOHOL CONSUMPTION MAY BE ASSOCIATED WITH EPIGENETIC AGING IN A TISSUE-SPECIFIC MANNER AND WARRANTS FURTHER INVESTIGATION USING MULTIPLE TISSUE SAMPLES FROM THE SAME INDIVIDUALS. 2018 7 846 41 CHILDHOOD EXPOSURE TO AMBIENT POLYCYCLIC AROMATIC HYDROCARBONS IS LINKED TO EPIGENETIC MODIFICATIONS AND IMPAIRED SYSTEMIC IMMUNITY IN T CELLS. BACKGROUND: EVIDENCE SUGGESTS THAT EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) INCREASES ATOPY; IT IS UNCLEAR HOW PAH EXPOSURE IS LINKED TO INCREASED SEVERITY OF ATOPIC DISEASES. OBJECTIVE: WE HYPOTHESIZED THAT AMBIENT PAH EXPOSURE IS LINKED TO IMPAIRMENT OF IMMUNITY IN ATOPIC CHILDREN (DEFINED AS CHILDREN WITH ASTHMA AND/OR ALLERGIC RHINITIS) FROM FRESNO, CALIFORNIA, AN AREA WITH ELEVATED AMBIENT PAHS. METHODS: WE RECRUITED 256 SUBJECTS FROM FRESNO, CA. AMBIENT PAH CONCENTRATIONS (NG/M(3) ) WERE MEASURED USING A SPATIAL-TEMPORAL REGRESSION MODEL OVER MULTIPLE TIME PERIODS. ASTHMA DIAGNOSIS WAS DETERMINED BY CURRENT NHLBI CRITERIA. PHENOTYPING AND FUNCTIONAL IMMUNE MEASUREMENTS WERE PERFORMED FROM ISOLATED CELLS. FOR EPIGENETIC MEASUREMENTS, DNA WAS ISOLATED AND PYROSEQUENCED. RESULTS: WE SHOW THAT HIGHER AVERAGE PAH EXPOSURE WAS SIGNIFICANTLY ASSOCIATED WITH IMPAIRED TREG FUNCTION AND INCREASED METHYLATION IN THE FORKHEAD BOX PROTEIN 3 (FOXP3) LOCUS (P < 0.05), CONDITIONAL ON ATOPIC STATUS. THESE EPIGENETIC MODIFICATIONS WERE SIGNIFICANTLY LINKED TO DIFFERENTIAL PROTEIN EXPRESSION OF FOXP3 (P < 0.001). METHYLATION WAS ASSOCIATED WITH CELLULAR FUNCTIONAL CHANGES, SPECIFICALLY TREG DYSFUNCTION, AND AN INCREASE IN TOTAL PLASMA IGE LEVELS. PROTEIN EXPRESSION OF IL-10 DECREASED AND IFN-GAMMA INCREASED AS THE EXTENT OF PAH EXPOSURE INCREASED. THE STRENGTH OF THE ASSOCIATIONS GENERALLY INCREASED AS THE TIME WINDOW FOR AVERAGE PAH EXPOSURE INCREASED FROM 24 HR TO 1 YEAR, SUGGESTING MORE OF A CHRONIC RESPONSE. SIGNIFICANT ASSOCIATIONS WITH CHRONIC PAH EXPOSURE AND IMMUNE OUTCOMES WERE ALSO OBSERVED IN SUBJECTS WITH ALLERGIC RHINITIS. CONCLUSIONS AND CLINICAL RELEVANCE: COLLECTIVELY, THESE RESULTS DEMONSTRATE THAT INCREASED AMBIENT PAH EXPOSURE IS ASSOCIATED WITH IMPAIRED SYSTEMIC IMMUNITY AND EPIGENETIC MODIFICATIONS IN A KEY LOCUS INVOLVED IN ATOPY: FOXP3, WITH A HIGHER IMPACT ON ATOPIC CHILDREN. THE RESULTS SUGGEST THAT INCREASED ATOPIC CLINICAL SYMPTOMS IN CHILDREN COULD BE LINKED TO INCREASED PAH EXPOSURE IN AIR POLLUTION. 2015 8 3954 40 LONG INTERSPERSED NUCLEAR ELEMENT-1 METHYLATION STATUS IN THE CIRCULATING DNA FROM BLOOD OF PATIENTS WITH MALIGNANT AND CHRONIC INFLAMMATORY LUNG DISEASES. ALONG WITH OTHER MALIGNANT DISEASES, LUNG CANCER ARISES FROM THE PRECANCEROUS LUNG TISSUE STATE. ABERRANT DNA METHYLATION (HYPERMETHYLATION OF CERTAIN GENES AND HYPOMETHYLATION OF RETROTRANSPOSONS) IS KNOWN AS ONE OF THE DRIVING FORCES OF MALIGNANT CELL TRANSFORMATION. EPIGENETIC CHANGES WERE SHOWN TO BE DETECTABLE IN DNA, CIRCULATING IN THE BLOOD (CIRDNA) OF CANCER PATIENTS, INDICATING THE POSSIBILITY TO USE THEM AS CANCER MARKERS. THE CURRENT STUDY IS THE FIRST TO COMPARE THE LONG INTERSPERSED NUCLEAR ELEMENT-1 (LINE-1) METHYLATION LEVEL IN THE BLOOD FROM LUNG CANCER PATIENTS BEFORE TREATMENT VERSUS DIFFERENT CONTROL GROUPS AS HEALTHY SUBJECTS, PATIENTS WITH BRONCHITIS AND PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THE CONCENTRATION OF LINE-1 METHYLATED FRAGMENTS, REGION 1 (LINE-1 METHYLATED, LINE-1-MET) WAS ESTIMATED BY QUANTITATIVE METHYL-SPECIFIC PCR. THE TOTAL CONCENTRATION OF THE CIRCULATING LINE-1 COPIES WAS MEASURED BY QPCR SPECIFIC FOR LINE-1 REGION 2, WHICH WAS SELECTED DUE TO ITS CPG METHYLATION-INDEPENDENT SEQUENCE (LINE-1-IND). BOTH LINE-1 METHYLATION LEVEL AND LINE-1 METHYLATION INDEX (LINE-1-MET/LINE-1-IND RATIO) WAS DECREASED IN LUNG CANCER PATIENTS COMPARED WITH THE JOINT CONTROL GROUP (HEALTHY SUBJECTS + PATIENTS WITH BRONCHITIS + COPD PATIENTS) (MANN-WHITNEY U-TEST, P = 0.016). WE ALSO FOUND THAT THE TENDENCY OF LINE-1 METHYLATION INDEX DECREASES IN THE CIRDNA FROM LUNG CANCER PATIENTS VERSUS COPD PATIENTS (MANN-WHITNEY U-TEST, P = 0.07). OUR DATA INDICATE THAT THE QUANTITATIVE ANALYSIS OF THE LINE-1 METHYLATION LEVEL IN THE CIRDNA IS VALUABLE FOR DISCRIMINATION OF LUNG CANCER PATIENTS FROM PATIENTS WITH CHRONIC INFLAMMATORY LUNG DISEASES. 2021 9 509 35 ASSOCIATION OF NUTRACEUTICAL SUPPLEMENTS WITH LONGER TELOMERE LENGTH. TELOMERES ARE NUCLEOTIDE TANDEM REPEATS LOCATED AT THE TIP OF EUKARYOTIC CHROMOSOMES THAT MAINTAIN GENOMIC INTEGRITY. THE GRADUAL SHORTENING OF TELOMERES LEADS TO CELLULAR SENESCENCE AND APOPTOSIS, A KEY MECHANISM OF AGING AND AGE?RELATED CHRONIC DISEASES. EPIGENETIC FACTORS, SUCH AS NUTRITION, EXERCISE AND TOBACCO CAN AFFECT THE RATE AT WHICH TELOMERES SHORTEN AND CAN MODIFY THE RISK OF DEVELOPING CHRONIC DISEASES. IN THIS STUDY, WE EVALUATED THE EFFECTS OF A COMBINATION OF NUTRACEUTICAL SUPPLEMENTS (NS) ON TELOMERE LENGTH (TL) IN HEALTHY VOLUNTEERS WITH NO MEDICAL HISTORY OF ANY DISEASE. PARTICIPANTS (N=47) WERE SELECTED FROM HEALTHY OUTPATIENTS VISITING A PRIVATE CLINIC AND WERE DIVIDED INTO THE EXPERIMENTAL GROUP (N=16), THAT RECEIVED THE NS AND THE CONTROL GROUP (N=31). WE ESTIMATED THE LENGTH OF SINGLE TELOMERES IN METAPHASE SPREAD LEUKOCYTES, ISOLATED FROM PERIPHERAL BLOOD, USING QUANTITATIVE?FLUORESCENT IN SITU HYBRIDIZATION (Q?FISH) ANALYSIS. THE LENGTH OF THE WHOLE TELOMERE GENOME WAS SIGNIFICANTLY INCREASED (P<0.05) FOR THE MEAN, 1ST QUARTILE AND MEDIAN MEASUREMENTS IN THE EXPERIMENTAL GROUP. SIMILAR FINDINGS WERE OBSERVED FOR SHORT TL (20TH PERCENTILE) (P<0.05) FOR THE MEDIAN AND 3RD QUARTILE MEASUREMENTS IN THE NS GROUP, COMPARED TO THE CONTROL GROUP. THE BENEFICIAL EFFECTS OF THE SUPPLEMENTS ON THE LENGTH OF SHORT TELOMERES REMAINED SIGNIFICANT (P<0.05) FOLLOWING ADJUSTMENT FOR AGE AND SEX. TELOMERES WERE MODERATELY LONGER IN FEMALE PATIENTS COMPARED TO THE MALE PATIENTS. ON THE WHOLE, THE FINDINGS OF THIS STUDY SUGGEST THAT THE ADMINISTRATION OF NS MAY BE LINKED TO SUSTAINING THE TL. 2019 10 143 32 ABERRANT DNA METHYLATION OF TWO TUMOR SUPPRESSOR GENES, P14(ARF) AND P15(INK4B), AFTER CHRONIC OCCUPATIONAL EXPOSURE TO LOW LEVEL OF BENZENE. BACKGROUND: EXPOSURE TO BENZENE WOULD BE ASSOCIATED WITH MANY DISEASES INCLUDING LEUKEMIA. EPIGENETIC ALTERATIONS SEEM TO BE AMONG THE MAIN MECHANISMS INVOLVED. OBJECTIVE: TO DETERMINE IF CHRONIC OCCUPATIONAL EXPOSURE TO LOW LEVEL OF BENZENE WOULD BE ASSOCIATED WITH DNA METHYLATION. METHODS: GLOBAL DNA METHYLATION AND PROMOTER-SPECIFIC METHYLATION OF THE TWO TUMOR SUPPRESSOR GENES, P14(ARF) AND P15(INK4B), WERE ASSESSED EMPLOYING METHYLATION-SPECIFIC PCR USING THE DNA EXTRACTED FROM 40 PETROCHEMICAL WORKERS EXPOSED TO AMBIENT BENZENE LEVELS OF <1 PPM, AND 31 OFFICE WORKERS NOT EXPOSED TO BENZENE OR ITS DERIVATIVES. RESULTS: WHILE AN INCREASE IN GLOBAL DNA METHYLATION OF 5% IN P14(ARF) (P=0.501) AND 28% IN P15(INK4B) (P=0.02) GENES WAS OBSERVED IN THE EXPOSED GROUP, NO HYPERMETHYLATION IN EITHER OF THE STUDIED GENES WAS OBSERVED IN THE UNEXPOSED GROUP. NO SIGNIFICANT ASSOCIATION WAS FOUND BETWEEN THE FREQUENCY OF ABERRANT METHYLATION AND EITHER OF AGE, WORK EXPERIENCE, AND SMOKING HABIT IN THE EXPOSED GROUP. CONCLUSION: CHRONIC OCCUPATIONAL EXPOSURE TO LOWER THAN THE PERMISSIBLE EXPOSURE LIMIT OF BENZENE MAY STILL RESULT IN DNA METHYLATION OF TUMOR SUPPRESSOR GENES THAT MAY ULTIMATELY LEAD TO DEVELOPMENT OF CANCER. 2018 11 1849 31 EIGHT WEEKS OF PHYSICAL TRAINING DECREASES 2 YEARS OF DNA METHYLATION AGE OF SEDENTARY WOMEN. PURPOSE: THE ACCELERATION OF EPIGENETIC AGE IS A PREDICTOR OF MORTALITY AND CONTRIBUTES TO THE INCREASE IN CHRONIC DISEASES. ADHERENCE TO A HEALTHY LIFESTYLE IS A STRATEGY TO REDUCE EPIGENETIC AGE. THE PRESENT STUDY AIMED TO DETERMINE WHETHER EIGHT WEEKS OF COMBINED (AEROBIC AND STRENGTH) TRAINING (CT) CAN INFLUENCE THE EPIGENETIC AGE OF WOMEN BETWEEN 50 AND 70 YEARS OLD AND THE DIFFERENCES IN SITES AND METHYLATED REGIONS. METHODS: EIGHTEEN WOMEN (AAR(LOW): LOWER AGE ACCELERATION RESIDUAL, N = 10; AAR(HIGH): HIGHER AGE ACCELERATION RESIDUAL, N = 8) PARTICIPATED IN A COMBINED EXERCISE TRAINING PROGRAM (60 MINUTES, 3X A WEEK) FOR EIGHT WEEKS. DNA WAS EXTRACTED FROM WHOLE BLOOD USING THE SALTING OUT TECHNIQUE. DNA METHYLATION WAS PERFORMED USING THE ARRAY TECHNIQUE (ILLUMINA'S INFINIUM METHYLATION BEADCHIP 850K). WE USED THE DNA METHYLATION AGE CALCULATOR PLATFORM TO CALCULATE THE BIOLOGICAL EPIGENETIC AGE. TWO-WAY ANOVA FOLLOWED BY FISHER LSD POSTHOC WAS APPLIED, ADOPTING P < .05. RESULTS: AFTER EIGHT WEEKS OF CT, THERE WERE NO CHANGES TO THE EPIGENETIC AGE ACCELERATION FOR THE AAR(LOW) GROUP (PRE: -2.3 +/- 3.2 TO POST: -2.3 +/- 3.6). HOWEVER, THE AAR(HIGH) GROUP SIGNIFICANTLY DECREASED THE AGE ACCELERATION (PRE: 3.6 +/- 2.6 TO POST: 2.2 +/- 2.7) (GROUP EFFECT, P = .01; TIME EFFECT, P = .31; GROUP VS. TIME EFFECT, P = .005). CONCLUSION: CT FOR EIGHT WEEKS BENEFITS THE EPIGENETIC CLOCK OF WOMEN WITH THE MOST ACCELERATED AGE. 2023 12 3442 35 HYPERMETHYLATION IN THE PROMOTER OF THE MTHFR GENE IS ASSOCIATED WITH DIABETIC COMPLICATIONS AND BIOCHEMICAL INDICATORS. BACKGROUND: DNA METHYLATION IS AN EPIGENETIC MECHANISM FOR REGULATING THE TRANSCRIPTION OF MANY GENES AND HAS BEEN LINKED TO THE DEVELOPMENT OF VARIOUS DISEASES. A PROMISING GENE TO INVESTIGATE IS METHYLENETETRAHYDROFOLATE REDUCTASE (MTHFR), SINCE THE ENZYME METHYLENETETRAHYDROFOLATE REDUCTASE (MTHFR) PROMOTES METHYL RADICAL SYNTHESIS IN THE HOMOCYSTEINE CYCLE AND CAN PROVIDE METHYL GROUPS FOR DNA METHYLATION. IN ADDITION, SEVERAL STUDIES HAVE CORRELATED GENE POLYMORPHISMS OF THIS ENZYME WITH A GREATER RISK OF DIABETES, BUT LITTLE IS KNOWN REGARDING THE RELATIONSHIP BETWEEN EPIGENETIC CHANGES IN THIS GENE AND DIABETES AND ITS COMPLICATIONS. THE AIM OF THIS STUDY WAS TO INVESTIGATE THE RELATIONSHIP BETWEEN METHYLATION PROFILE IN THE MTHFR GENE PROMOTER AND BIOCHEMICAL, INFLAMMATORY AND OXIDATIVE STRESS MARKERS IN INDIVIDUALS WITH TYPE 2 DIABETES (T2DM) WHO HAVE BEEN DIAGNOSED FOR 5-10 YEARS WITH OR WITHOUT DIABETIC RETINOPATHY (DR) AND NEPHROPATHY (DN). METHODS: SPECIFIC PCR FOR METHYLATION (MSP) WAS USED TO ANALYZE MTHFR METHYLATION PROFILE IN LEUCOCYTES DNA. BIOCHEMICAL MARKERS (GLYCEMIA, GLYCATED HEMOGLOBIN, TOTAL CHOLESTEROL, LDL, HDL, TRIGLYCERIDES, SERUM CREATININE), INFLAMMATORY MARKERS (C-REACTIVE PROTEIN AND ALPHA-1 ACID GLYCOPROTEIN) AND OXIDATIVE STRESS (TOTAL ANTIOXIDANT AND MALONALDEHYDE) WERE DETERMINED IN PERIPHERIC BLOOD SAMPLES AND MICROALBUMINURIA IN 24 H URINE SAMPLES. THE X(2) AND MANN-WHITNEY STATISTICAL TESTS WERE PERFORMED AND P < 0.05 WERE CONSIDERED SIGNIFICANT. RESULTS: THE HYPERMETHYLATED PROFILE WAS MOST FREQUENTLY OBSERVED IN INDIVIDUALS WITH RETINOPATHY (P < 0.01) AND WAS ASSOCIATED WITH HIGHER TOTAL CHOLESTEROL AND LDL LEVELS (P = 0.0046, 0.0267, RESPECTIVELY). INDIVIDUALS WITH DN AND HYPERMETHYLATED PROFILES HAD HIGHER LEVELS OF ALPHA-1 ACID GLYCOPROTEIN (P = 0.0080) AND TOTAL ANTIOXIDANT CAPACITY (P = 0.0169) COMPARED TO SUBJECTS WITHOUT COMPLICATIONS. CONCLUSIONS: HYPERMETHYLATION IN THE PROMOTER OF THE MTHFR GENE IS ASSOCIATED WITH THE OCCURRENCE OF DR AND WITH BIOCHEMICAL, INFLAMMATORY AND OXIDATIVE STRESS PARAMETERS IN THE CONTEXT OF CHRONIC COMPLICATIONS. 2017 13 1805 30 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 14 3387 21 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 15 6311 36 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 16 5628 32 SEMEN ABNORMALITIES, SPERM DNA DAMAGE AND GLOBAL HYPERMETHYLATION IN HEALTH WORKERS OCCUPATIONALLY EXPOSED TO IONIZING RADIATION. BACKGROUND: CYTOGENETIC STUDIES HAVE DEMONSTRATED THAT LOW LEVELS OF CHRONIC RADIATION EXPOSURE CAN POTENTIALLY INCREASE THE FREQUENCY OF CHROMOSOMAL ABERRATIONS AND ANEUPLOIDY IN SOMATIC CELLS. EPIDEMIOLOGICAL STUDIES HAVE SHOWN THAT HEALTH WORKERS OCCUPATIONALLY EXPOSED TO IONIZING RADIATION BEAR AN INCREASED RISK OF HEMATOLOGICAL MALIGNANCIES. OBJECTIVES: TO FIND THE INFLUENCE OF OCCUPATIONAL RADIATION EXPOSURE ON SEMEN CHARACTERISTICS, INCLUDING GENETIC AND EPIGENETIC INTEGRITY OF SPERMATOZOA IN A CHRONICALLY EXPOSED POPULATION. METHODS: THIS CROSS SECTIONAL STUDY INCLUDED 134 MALE VOLUNTEERS OF WHICH 83 WERE OCCUPATIONALLY EXPOSED TO IONIZING RADIATION AND 51 WERE NON-EXPOSED CONTROL SUBJECTS. SEMEN CHARACTERISTICS, SPERM DNA FRAGMENTATION, ANEUPLOIDY AND INCIDENCE OF GLOBAL HYPERMETHYLATION IN THE SPERMATOZOA WERE DETERMINED AND COMPARED BETWEEN THE NON-EXPOSED AND THE EXPOSED GROUP. RESULTS: DIRECT COMPARISON OF THE SEMEN CHARACTERISTICS BETWEEN THE NON-EXPOSED AND THE EXPOSED POPULATION REVEALED SIGNIFICANT DIFFERENCES IN MOTILITY CHARACTERISTICS, VIABILITY, AND MORPHOLOGICAL ABNORMALITIES (P<0.05-0.0001). ALTHOUGH, THE LEVEL OF SPERM DNA FRAGMENTATION WAS SIGNIFICANTLY HIGHER IN THE EXPOSED GROUP AS COMPARED TO THE NON-EXPOSED GROUP (P<0.05-0.0001), THE INCIDENCE OF SPERM ANEUPLOIDY WAS NOT STATISTICALLY DIFFERENT BETWEEN THE TWO GROUPS. HOWEVER, A SIGNIFICANT NUMBER OF HYPERMETHYLATED SPERMATOZOA WERE OBSERVED IN THE EXPOSED GROUP IN COMPARISON TO NON-EXPOSED GROUP (P<0.05). CONCLUSIONS: WE PROVIDE THE FIRST EVIDENCE ON THE DETRIMENTAL EFFECTS OF OCCUPATIONAL RADIATION EXPOSURE ON FUNCTIONAL, GENETIC AND EPIGENETIC INTEGRITY OF SPERM IN HEALTH WORKERS. HOWEVER, FURTHER STUDIES ARE REQUIRED TO CONFIRM THE POTENTIAL DETRIMENTAL EFFECTS OF IONIZING RADIATION IN THESE SUBJECTS. 2013 17 5722 43 SISTER CHROMATID EXCHANGE AND PROLIFERATIVE RATE INDEX IN THE LONGITUDINAL RISK ASSESSMENT OF OCCUPATIONAL EXPOSURE TO PESTICIDES. AT PRESENT, THERE ARE MORE THAN 1,000 CHEMICALS CLASSIFIED AS PESTICIDES AND MANY REPORTS HAVE SHOWN THAT SOME OF THEM HAVE GENOTOXIC PROPERTIES. IN THE PRESENT LONGITUDINAL STUDY, POSSIBLE GENETIC DAMAGE ON A POPULATION OF WORKERS OCCUPATIONALLY EXPOSED TO A MIXTURE OF PESTICIDES BY USING SISTER CHROMATID EXCHANGE (SCE) ANALYSIS HAS BEEN EVALUATED. AS AN ADDITIONAL CYTOGENETIC PARAMETER, THE PROPORTION OF LYMPHOCYTES THAT UNDERGO ONE, TWO OR THREE CELL DIVISIONS AS WELL AS PROLIFERATIVE RATE INDEX HAVE BEEN DETERMINED. THIS STUDY WAS PERFORMED ON THE EXPOSED GROUP OF WORKERS EMPLOYED IN PESTICIDE PRODUCTION, SIMULTANEOUSLY EXPOSED TO A COMPLEX MIXTURE OF PESTICIDES (ATRAZINE, ALACHLOR, CYANAZINE, 2,4-DICHLOROPHENOXYACETIC ACID, AND MALATHION). THE BLOOD SAMPLES OF THE EXPOSED SUBJECTS WERE COLLECTED IN THREE DIFFERENT PERIODS: BEFORE THE BEGINNING OF THE NEW PESTICIDE PRODUCTION PERIOD, AFTER 8 MONTHS OF EVERYDAY WORK IN THE PESTICIDE PRODUCTION, AND 8 MONTHS AFTER THE REMOVAL OF SUBJECTS OUT OF THE PRODUCTION. IN ALL THREE SAMPLINGS, THE MEAN VALUE OF SCE AND NUMBER OF CELLS WITH HIGH SISTER CHROMATID EXCHANGE FREQUENCY (HFC) IN THE EXPOSED GROUP WAS SIGNIFICANTLY HIGHER IN THE COMPARISON WITH THE CONTROL GROUP. THERE WERE NO DIFFERENCES IN THE PROLIFERATIVE RATE INDEX (PRI) BETWEEN THE CONTROL AND EXPOSED GROUP, REGARDLESS OF THE SAMPLING PERIOD. IN BOTH GROUPS EXAMINED, THE MAJORITY OF LYMPHOCYTES WERE FOUND IN THE SECOND CELL DIVISION, FOLLOWING CULTIVATION. THESE RESULTS SUGGEST THAT THE INCREASE IN THE NUMBER OF SCE FOUND IN THE EXPOSED SUBJECTS IS NOT THE RESULT OF EITHER CYTOTOXIC OR EPIGENETIC ACTION OF PESTICIDE MIXTURE, BUT CHRONIC OCCUPATIONAL EXPOSURE TO MIXTURE OF PESTICIDES. 2002 18 1537 30 DNA METHYLATION IN ADOLESCENTS WITH ANXIETY DISORDER: A LONGITUDINAL STUDY. ANXIETY DISORDERS (AD) TYPICALLY MANIFEST IN CHILDREN AND ADOLESCENTS AND MIGHT PERSIST INTO ADULTHOOD. HOWEVER, THERE ARE STILL FEW DATA CONCERNING EPIGENETIC MECHANISMS ASSOCIATED WITH ONSET, PERSISTENCE OR REMISSION OF AD OVER TIME. WE INVESTIGATED A COHORT OF ADOLESCENTS AND YOUNG ADULTS AT BASELINE (AGE; 13.19 +/- 2.38) AND AFTER 5 YEARS AND CLASSIFIED THEM ACCORDING TO THE AD DIAGNOSIS AND THEIR LONGITUDINAL TRAJECTORIES INTO 4 GROUPS: (1) TYPICALLY DEVELOPING COMPARISONS (TDC; CONTROL GROUP, N = 14); (2) INCIDENT (AD IN THE SECOND EVALUATION ONLY, N = 11); (3) PERSISTENT (AD IN BOTH EVALUATIONS, N = 14) AND (4) REMITTENT (AD IN THE FIRST EVALUATION ONLY, N = 8). DNA METHYLATION WAS EVALUATED WITH THE INFINIUM HUMANMETHYLATION450 BEADCHIP FROM SALIVA SAMPLES COLLECTED AT BOTH EVALUATIONS. GENE SET ENRICHMENT ANALYSIS WAS APPLIED TO CONSIDER BIOLOGICAL PATHWAYS. WE FOUND DECREASED DNA METHYLATION IN TDC GROUP WHILE THE CHRONIC CASES OF AD PRESENTED HYPERMETHYLATION IN CENTRAL NERVOUS SYSTEM DEVELOPMENT PATHWAYS. MOREOVER, WE SHOWED THAT THIS PERSISTENT GROUP ALSO PRESENTED HYPERMETHYLATION WHILE THE OTHER THREE GROUPS WERE ASSOCIATED WITH HYPOMETHYLATION IN NERVOUS SYSTEM DEVELOPMENT PATHWAY. INCIDENCE AND REMISSION GROUPS WERE ASSOCIATED WITH INCREASED AND DECREASED METHYLATION IN NEURON DEVELOPMENT PATHWAYS, RESPECTIVELY. LARGER STUDIES ARE LIKELY TO DETECT SPECIFIC GENES RELEVANT TO AD. 2018 19 1573 36 DNA METHYLATION PATTERNS IN NEWBORNS EXPOSED TO TOBACCO IN UTERO. BACKGROUND: MATERNAL SMOKING DURING PREGNANCY IS A MAJOR RISK FACTOR FOR ADVERSE HEALTH OUTCOMES. THE MAIN OBJECTIVE OF THE STUDY WAS TO ASSESS THE IMPACT OF IN UTERO TOBACCO EXPOSURE ON DNA METHYLATION IN CHILDREN BORN AT TERM WITH APPROPRIATE WEIGHT AT BIRTH. METHODS: TWENTY MOTHER-NEWBORN DYADS, AFTER UNCOMPLICATED PREGNANCIES, IN THE ABSENCE OF PERINATAL ILLNESS WERE INCLUDED. ALL MOTHERS WERE HEALTHY WITH NO CARDIOVASCULAR RISK FACTORS, EXCEPT FOR THE ASSOCIATED RISKS AMONG THOSE MOTHERS WHO SMOKED. UMBILICAL CORD BLOOD AND MATERNAL PERIPHERAL VENOUS BLOOD WERE COLLECTED AND AN EPIGENOME-WIDE ASSOCIATION STUDY WAS PERFORMED USING A 450 K EPIGENOME-WIDE SCAN (ILLUMINA INFINIUM HUMANMETHYLATION 450BEADCHIP) WITH ADJUSTMENT TO NORMALIZE THE DNA METHYLATION FOR DATA CELL VARIABILITY IN WHOLE BLOOD. RESULTS: THE MATERNAL PLASMATIC COTININE LEVELS RANGED FROM 10.70-115.40 NG/ML IN THE EXPOSED GROUP TO 0-0.59 NG/ML IN THE NON-EXPOSED GROUP. AFTER ADJUSTING FOR MULTIPLE COMPARISONS IN 427102 PROBES, STATISTICALLY SIGNIFICANT DIFFERENCES FOR 31 CPG SITES, ASSOCIATED TO 25 GENES WERE OBSERVED. THERE WAS A GREATER THAN EXPECTED PROPORTION OF STATISTICALLY-SIGNIFICANT LOCI LOCATED IN CPG ISLANDS (FISHER'S EXACT TEST, P = 0.029) AND OF THOSE CPG ISLANDS, 90.3% EXHIBIT HIGHER METHYLATION LEVELS IN THE EXPOSED GROUP. THE MOST STRIKING AND SIGNIFICANT CPG SITE, CG05727225, IS LOCATED IN THE CHROMOSOME 11P15.4, WITHIN THE ADRENOMEDULLIN GENE. CONCLUSIONS: IN UTERO TOBACCO EXPOSURE, EVEN IN THE ABSENCE OF FETAL GROWTH RESTRICTION, MAY ALTER THE EPIGENOME, CONTRIBUTING TO GLOBAL DNA HYPOMETHYLATION. THEREFORE, DNA STATUS CAN BE USED AS A BIOMARKER OF PRENATAL INSULTS. CONSIDERING THE POSSIBILITY TO REVERSE EPIGENETIC MODIFICATIONS, A WINDOW OF OPPORTUNITY EXISTS TO CHANGE THE PROGRAMMED CHRONIC DISEASE. 2015 20 1553 40 DNA METHYLATION LEVELS ASSOCIATED WITH RACE AND CHILDHOOD ASTHMA SEVERITY. OBJECTIVE: ASTHMA IS A COMMON CHRONIC CHILDHOOD DISEASE WORLDWIDE. SOCIOECONOMIC STATUS, GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS CONTRIBUTE TO ITS INCIDENCE AND SEVERITY. A DISPROPORTIONATE NUMBER OF CHILDREN WITH ASTHMA ARE ECONOMICALLY DISADVANTAGED AND LIVE IN SUBSTANDARD HOUSING WITH POTENTIAL INDOOR ENVIRONMENTAL EXPOSURES SUCH AS COCKROACHES, DUST MITES, RODENTS AND MOLDS. THESE EXPOSURES MAY MANIFEST THROUGH EPIGENETIC MECHANISMS THAT CAN LEAD TO CHANGES IN RELEVANT GENE EXPRESSION. WE EXAMINED THE ASSOCIATION OF GLOBAL DNA METHYLATION LEVELS WITH SOCIOECONOMIC STATUS, ASTHMA SEVERITY AND RACE/ETHNICITY. METHODS: WE MEASURED GLOBAL DNA METHYLATION IN PERIPHERAL BLOOD OF CHILDREN WITH ASTHMA ENROLLED IN THE KANSAS CITY SAFE AND HEALTHY HOMES PROGRAM. INCLUSION CRITERIA INCLUDED RESIDING IN THE SAME HOME FOR A MINIMUM OF 4 DAYS PER WEEK AND TOTAL FAMILY INCOME OF LESS THAN 80% OF THE KANSAS CITY MEDIAN FAMILY INCOME. DNA METHYLATION LEVELS WERE QUANTIFIED BY AN IMMUNOASSAY THAT ASSESSED THE PERCENTAGE OF 5-METHYLCYTOSINE. RESULTS: OUR RESULTS INDICATE THAT OVERALL, AFRICAN AMERICAN CHILDREN HAD HIGHER LEVELS OF GLOBAL DNA METHYLATION THAN CHILDREN OF OTHER RACES/ETHNICITIES (P = 0.029). THIS DIFFERENCE WAS MORE PRONOUNCED WHEN SOCIOECONOMIC STATUS AND ASTHMA SEVERITY WERE COUPLED WITH RACE/ETHNICITY (P = 0.042) WHERE LOW-INCOME, AFRICAN AMERICAN CHILDREN WITH PERSISTENT ASTHMA HAD SIGNIFICANTLY ELEVATED METHYLATION LEVELS RELATIVE TO OTHER RACES/ETHNICITIES IN THE SAME CONTEXT (P = 0.006, HEDGES G = 1.14). CONCLUSION: OUR STUDY DEMONSTRATES A SIGNIFICANT INTERACTION EFFECT AMONG GLOBAL DNA METHYLATION LEVELS, ASTHMA SEVERITY, RACE/ETHNICITY, AND SOCIOECONOMIC STATUS. 2017