1 3558 139 IMPACT OF CHRONIC BENZENE POISONING ON ABERRANT MITOCHONDRIAL DNA METHYLATION: A PROSPECTIVE OBSERVATIONAL STUDY. BENZENE IS USED AS AN INDUSTRIAL SOLVENT, WHICH MAY RESULT IN CHRONIC BENZENE POISONING (CBP). SEVERAL STUDIES SUGGESTED THAT CBP WAS ASSOCIATED WITH MITOCHONDRIAL EPIGENETIC REGULATION. THIS STUDY AIMED TO EXPLORE THE POTENTIAL RELATION BETWEEN CBP AND MITOCHONDRIAL DNA (MTDNA) METHYLATION. THIS PROSPECTIVE OBSERVATIONAL STUDY ENROLLED CBP PATIENTS ADMITTED TO SHENZHEN PREVENTION AND TREATMENT CENTER FOR OCCUPATIONAL DISEASES HOSPITAL AND HEALTHY INDIVIDUALS BETWEEN 2018 AND 2021. THE WHITE BLOOD CELL (WBC), RED BLOOD CELL (RBC), HEMOGLOBIN (HB), AND PLATELET (PLT) COUNTS AND MTDNA METHYLATION LEVELS WERE MEASURED USING BLOOD FLOW CYTOMETRY AND TARGETED BISULFITE SEQUENCING, RESPECTIVELY. A TOTAL OF 90 PARTICIPANTS WERE RECRUITED, INCLUDING 30 CASES OF CBP (20 FEMALES, MEAN AGE 43.0 +/- 8.0 YEARS) AND 60 HEALTHY INDIVIDUALS (42 FEMALES, MEAN AGE 43.5 +/- 11.5 YEARS). THIS STUDY DETECTED 168 MITOCHONDRIAL METHYLATION SITES >0 IN ALL STUDY SUBJECTS. THE MTDNA METHYLATION LEVELS IN THE CBP CASES WERE LOWER THAN THE HEALTHY INDIVIDUALS [MEDIAN +/- INTERQUARTILE-RANGE (IQR), 25TH PERCENTILE, 75TH PERCENTILE: (1.140 +/- 0.570, 0.965, 1.535)% VS. MEDIAN +/- IQR, 25TH PERCENTILE, 75TH PERCENTILE: (1.705 +/- 0.205,1.240,2.445)%, P < 0.05]. ADDITIONALLY, THE SPEARMAN CORRELATION ANALYSIS SHOWED THAT THE MTDNA METHYLATION LEVELS WERE POSITIVELY CORRELATED WITH THE COUNTS OF CIRCULATING LEUKOCYTES [WBC (R = 0.048, P = 0.036)] AND PLATELETS [PLT (R = 0.129, P < 0.01)]. WE PROVIDED SOLID EVIDENCE OF ASSOCIATION BETWEEN CBP AND ABERRANT MTDNA METHYLATION. 2023 2 5330 37 PUTATIVE EPIGENETIC BIOMARKERS OF STRESS IN RED BLOOD CELLS OF CHICKENS REARED ACROSS DIFFERENT BIOMES. PRODUCTION ANIMALS ARE CONSTANTLY SUBJECTED TO EARLY ADVERSE ENVIRONMENTAL CONDITIONS THAT INFLUENCE THE ADULT PHENOTYPE AND PRODUCE EPIGENETIC EFFECTS. CPG DINUCLEOTIDE METHYLATION IN RED BLOOD CELLS (RBC) COULD BE A USEFUL EPIGENETIC BIOMARKER TO IDENTIFY ANIMALS SUBJECTED TO CHRONIC STRESS IN THE PRODUCTION ENVIRONMENT. HERE WE COMPARED A REDUCED FRACTION OF THE RBC METHYLOME OF CHICKENS EXPOSED TO SOCIAL ISOLATION TO NON-EXPOSED. THESE EXPERIMENTS WERE PERFORMED IN TWO DIFFERENT LOCATIONS: BRAZIL AND SWEDEN. THE AIM WAS TO IDENTIFY STRESS-ASSOCIATED DNA METHYLATION PROFILES IN RBC ACROSS THESE POPULATIONS, IN SPITE OF THE VARIABLE CONDITIONS TO WHICH BIRDS ARE EXPOSED IN EACH FACILITY AND THEIR DIFFERENT LINEAGES. BIRDS WERE INCREASINGLY EXPOSED TO A SOCIAL ISOLATION TREATMENT, COMBINED WITH FOOD AND WATER DEPRIVATION, AT RANDOM PERIODS OF THE DAY FROM WEEKS 1-4 AFTER HATCHING. WE THEN COLLECTED THE RBC DNA FROM INDIVIDUALS AND COMPARED A REDUCED FRACTION OF THEIR METHYLOME BETWEEN THE EXPERIMENTAL GROUPS USING TWO BIOINFORMATIC APPROACHES TO IDENTIFY DIFFERENTIALLY METHYLATED REGIONS (DMRS): ONE USING FIXED-SIZE WINDOWS AND ANOTHER THAT PRESELECTED DIFFERENTIAL PEAKS WITH MACS2. THREE LEVELS OF SIGNIFICANCE WERE USED (P 50%) OF SPECIFIC TRANSCRIPTION FACTOR BINDING SITES. THREE OVERLAPPING DMRS WERE FOUND BETWEEN THE BR AND SW POPULATION USING THE MOST RELAXED P-VALUE (P R < 0.76, ALL P VALUES < 0.0001). THE MULTIVARIATE LINEAR REGRESSION ADJUSTING FOR GLOBAL METHYLATION SHOWED THAT AS(III) LEVEL WAS SIGNIFICANTLY ASSOCIATED WITH EXPRESSION OF TXNRD1, GSTP1, HMOX1, AND PRDX1. THE RESULTS OF THIS STUDY INDICATE THAT ARSENIC OCCUPATIONAL EXPOSURE IS POSITIVELY ASSOCIATED WITH GLOBAL DNA METHYLATION. THE FINDINGS PROVIDE EVIDENCE FOR RATHER INACTIVATION OF NRF2-KEAP1 PATHWAY IN RESPONSE TO CHRONIC ARSENIC EXPOSURE. 2018 6 2678 29 EVALUATION OF A PROGNOSTIC EPIGENETIC CLASSIFICATION SYSTEM IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS. BACKGROUND: METHYLATION AT 5 CPG SITES WAS PREVIOUSLY SHOWN TO CLASSIFY CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) INTO 3 PROGNOSTIC SUBGROUPS. HERE, WE AIMED TO VALIDATE THE MARKER SET IN AN ADDITIONAL COHORT AND TO EVALUATE ITS CLINICAL UTILITY FOR CLL PATIENT STRATIFICATION. METHODS: WE EVALUATED THIS EPIGENETIC MARKER SET IN 79 GERMAN PATIENTS USING BISULFITE TREATMENT FOLLOWED BY PYROSEQUENCING AND CLASSIFICATION USING A SUPPORT VECTOR MACHINE-LEARNING TOOL. RESULTS: THE N-CLL, I-CLL, AND M-CLL CLASSIFICATION WAS DETECTED IN 28 (35%), 10 (13%), AND 41 (51%) PATIENTS, RESPECTIVELY. EPIGENETIC GROUPING WAS ASSOCIATED WITH IGHV MUTATIONAL STATUS (P = 2 X 10(-12)), ISOLATED DEL13Q (P = 9 X 10(-6)), DEL17P (P = .015), COMPLEX KARYOTYPE (P = .005), VH-USAGE, AND CLINICAL OUTCOME AS TIME TO FIRST TREATMENT (P = 1.4 X 10(-12)) AND OVERALL SURVIVAL (P = .003). MULTIVARIATE COX REGRESSION ANALYSIS IDENTIFIED N-CLL AS A FACTOR FOR EARLIER TREATMENT HAZARD RATIO (HR), 6.3 (95% CONFIDENCE INTERVAL [CI] 2.4-16.4; P = .0002) COMPARED TO IGHV MUTATIONAL STATUS (HR 4.6, 95% CI 1.9-11.3, P = .0008). IN ADDITION, WHEN COMPARING THE PROGNOSTIC VALUE OF THE EPIGENETIC CLASSIFICATION SYSTEM WITH THE IGHV CLASSIFICATION, EPIGENETIC GROUPING PERFORMED BETTER COMPARED TO IGHV MUTATIONAL STATUS USING KAPLAN-MEIER ESTIMATION AND ALLOWED THE IDENTIFICATION OF A THIRD, INTERMEDIATE (I-CLL) GROUP. THUS, OUR STUDY CONFIRMED THE PROGNOSTIC VALUE OF THE EPIGENETIC MARKER SET FOR PATIENT STRATIFICATION IN ROUTINE CLINICAL DIAGNOSTICS. 2022 7 6491 40 TRAFFIC-DERIVED PARTICULATE MATTER EXPOSURE AND HISTONE H3 MODIFICATION: A REPEATED MEASURES STUDY. BACKGROUND: AIRBORNE PARTICULATE MATTER (PM) MAY INDUCE EPIGENETIC CHANGES THAT POTENTIALLY LEAD TO CHRONIC DISEASES. HISTONE MODIFICATIONS REGULATE GENE EXPRESSION BY INFLUENCING CHROMATIN STRUCTURE THAT CAN CHANGE GENE EXPRESSION STATUS. WE EVALUATED WHETHER TRAFFIC-DERIVED PM EXPOSURE IS ASSOCIATED WITH FOUR TYPES OF ENVIRONMENTALLY INDUCIBLE GLOBAL HISTONE H3 MODIFICATIONS. METHODS: THE BEIJING TRUCK DRIVER AIR POLLUTION STUDY INCLUDED 60 TRUCK DRIVERS AND 60 OFFICE WORKERS EXAMINED TWICE, 1-2 WEEKS APART, FOR AMBIENT PM(10) (BOTH DAY-OF AND 14-DAY AVERAGE EXPOSURES), PERSONAL PM(2.5), BLACK CARBON (BC), AND ELEMENTAL COMPONENTS (POTASSIUM, SULFUR, IRON, SILICON, ALUMINUM, ZINC, CALCIUM, AND TITANIUM). FOR BOTH PM(10) MEASURES, WE OBTAINED HOURLY AMBIENT PM(10) DATA FOR THE STUDY PERIOD FROM THE BEIJING MUNICIPAL ENVIRONMENTAL BUREAU'S 27 REPRESENTATIVELY DISTRIBUTED MONITORING STATIONS. WE THEN CALCULATED A 24H AVERAGE FOR EACH EXAMINATION DAY AND A MOVING AVERAGE OF AMBIENT PM(10) MEASURED IN THE 14 DAYS PRIOR TO EACH EXAMINATION. EXAMINATIONS MEASURED GLOBAL LEVELS OF H3 LYSINE 9 ACETYLATION (H3K9AC), H3 LYSINE 9 TRI-METHYLATION (H3K9ME3), H3 LYSINE 27 TRI-METHYLATION (H3K27ME3), AND H3 LYSINE 36 TRI-METHYLATION (H3K36ME3) IN BLOOD LEUKOCYTES COLLECTED AFTER WORK. WE USED ADJUSTED LINEAR MIXED-EFFECT MODELS TO EXAMINE PERCENT CHANGES IN HISTONE MODIFICATIONS PER EACH MUG/M(3) INCREASE IN PM EXPOSURE. RESULTS: IN ALL PARTICIPANTS EACH MUG/M(3) INCREASE IN 14-DAY AVERAGE AMBIENT PM(10) EXPOSURE WAS ASSOCIATED WITH LOWER H3K27ME3 (BETA=-1.1%, 95% CI: -1.6, -0.6) AND H3K36ME3 LEVELS (BETA=-0.8%, 95% CI: -1.4, -0.1). OCCUPATION-STRATIFIED ANALYSES SHOWED ASSOCIATIONS BETWEEN BC AND BOTH H3K9AC AND H3K36ME3 THAT WERE STRONGER IN OFFICE WORKERS (BETA=4.6%, 95% CI: 0.9, 8.4; AND BETA=4.1%, 95% CI: 1.3; 7.0 RESPECTIVELY) THAN IN TRUCK DRIVERS (BETA=0.1%, 95% CI: -1.3, 1.5; AND BETA=0.9%, 95% CI: -0.9, 2.7, RESPECTIVELY; BOTH P(INTERACTION) <0.05). SEX-STRATIFIED ANALYSES SHOWED ASSOCIATIONS BETWEEN EXAMINATION-DAY PM(10) AND H3K9AC, AND BETWEEN BC AND H3K9ME3, WERE STRONGER IN WOMEN (BETA=10.7%, 95% CI: 5.4, 16.2; AND BETA=7.5%, 95% CI: 1.2, 14.2, RESPECTIVELY) THAN IN MEN (BETA=1.4%, 95% CI: -0.9, 3.7; AND BETA=0.9%, 95% CI: -0.9, 2.7, RESPECTIVELY; BOTH P(INTERACTION) <0.05). WE OBSERVED NO ASSOCIATIONS BETWEEN PERSONAL PM(2.5) OR ELEMENTAL COMPONENTS AND HISTONE MODIFICATIONS. CONCLUSIONS: OUR RESULTS SUGGEST A POSSIBLE ROLE OF GLOBAL HISTONE H3 MODIFICATIONS IN EFFECTS OF TRAFFIC-DERIVED PM EXPOSURES, PARTICULARLY BC EXPOSURE. FUTURE STUDIES SHOULD ASSESS THE ROLES OF THESE MODIFICATIONS IN HUMAN DISEASES AND AS POTENTIAL MEDIATORS OF AIR POLLUTION-INDUCED DISEASE, IN PARTICULAR BC EXPOSURE. 2017 8 525 29 ASSOCIATIONS OF BODY COMPOSITION AND PHYSICAL ACTIVITY LEVEL WITH MULTIPLE MEASURES OF EPIGENETIC AGE ACCELERATION. EPIGENETIC CLOCKS USE DNA METHYLATION TO ESTIMATE BIOLOGICAL AGE. WHETHER BODY COMPOSITION AND PHYSICAL ACTIVITY ARE ASSOCIATED WITH THESE CLOCKS IS NOT WELL UNDERSTOOD. USING BLOOD SAMPLES COLLECTED AT ENROLLMENT (2003-2009) FROM 2,758 WOMEN IN THE US NATIONWIDE SISTER STUDY, WE CALCULATED 6 EPIGENETIC AGE ACCELERATION METRICS USING 4 EPIGENETIC CLOCKS (HANNUM, HORVATH, PHENOAGE, GRIMAGE). RECREATIONAL PHYSICAL ACTIVITY WAS SELF-REPORTED, AND ADIPOSITY MEASURES WERE ASSESSED BY TRAINED MEDICAL EXAMINERS (BODY MASS INDEX (BMI), WAIST-TO-HIP RATIO (WTH), WAIST CIRCUMFERENCE). IN CROSS-SECTIONAL ANALYSES, ALL ADIPOSITY MEASURES WERE ASSOCIATED WITH EPIGENETIC AGE ACCELERATION. THE STRONGEST ASSOCIATION WAS FOR BMI AND PHENOAGE, A MEASURE OF BIOLOGICAL AGE THAT CORRELATES WITH CHRONIC DISEASE (BMI OF >/=35.0 VS. 18.5-24.9, BETA = 3.15 YEARS, 95% CONFIDENCE INTERVAL (CI): 2.41, 3.90; P FOR TREND < 0.001). IN A MUTUAL-ADJUSTMENT MODEL, BOTH WERE ASSOCIATED WITH PHENOAGE AGE ACCELERATION (BMI OF >/=35.0 VS. 18.5-24.9, BETA = 2.69 YEARS, 95% CI: 1.90, 3.48; P FOR TREND < 0.001; QUARTILE 4 VS.1 WTH, BETA = 1.00 YEARS, 95% CI: 0.34, 1.65; P FOR TREND < 0.008). AFTER ADJUSTMENT, PHYSICAL ACTIVITY WAS ASSOCIATED ONLY WITH GRIMAGE (QUARTILE 4 VS. 1, BETA = -0.42 YEARS, 95% CI: -0.70, -0.14; P FOR TREND = 0.001). PHYSICAL ACTIVITY ATTENUATED THE WAIST CIRCUMFERENCE ASSOCIATIONS WITH PHENOAGE AND GRIMAGE. EXCESS ADIPOSITY WAS ASSOCIATED WITH EPIGENETIC AGE ACCELERATION; PHYSICAL ACTIVITY MIGHT ATTENUATE ASSOCIATIONS WITH WAIST CIRCUMFERENCE. 2021 9 4244 33 METHYLATION STATUS OF COX-2 IN BLOOD LEUKOCYTE DNA AND RISK OF GASTRIC CANCER IN A HIGH-RISK CHINESE POPULATION. BACKGROUND: METHYLATION IS A COMMON EPIGENETIC MODIFICATION WHICH MAY PLAY A CRUCIAL ROLE IN CANCER DEVELOPMENT. TO INVESTIGATE THE ASSOCIATION BETWEEN METHYLATION OF COX-2 IN BLOOD LEUKOCYTE DNA AND RISK OF GASTRIC CANCER (GC), A NESTED CASE-CONTROL STUDY WAS CONDUCTED IN LINQU COUNTY, SHANDONG PROVINCE, A HIGH RISK AREA OF GC IN CHINA. METHODS: ASSOCIATION BETWEEN BLOOD LEUKOCYTE DNA METHYLATION OF COX-2 AND RISK OF GC WAS INVESTIGATED IN 133 GCS AND 285 SUPERFICIAL GASTRITIS (SG)/ CHRONIC ATROPHIC GASTRITIS (CAG). THE TEMPORAL TREND OF COX-2 METHYLATION LEVEL DURING GC DEVELOPMENT WAS FURTHER EXPLORED IN 74 PRE-GC AND 95 POST-GC SAMPLES (INCLUDING 31 CASES WITH BOTH PRE- AND POST-GC SAMPLES). IN ADDITION, THE ASSOCIATION OF DNA METHYLATION AND RISK OF PROGRESSION TO GC WAS EVALUATED IN 74 PRE-GC SAMPLES AND THEIR RELEVANT INTESTINAL METAPLASIA (IM)/DYSPLASIA (DYS) CONTROLS. METHYLATION LEVEL WAS DETERMINED BY QUANTITATIVE METHYLATION-SPECIFIC PCR (QMSP). ODDS RATIOS (ORS) AND 95% CONFIDENCE INTERVALS (CIS) WERE CALCULATED BY UNCONDITIONAL LOGISTIC REGRESSION ANALYSIS. RESULTS: THE MEDIANS OF COX-2 METHYLATION LEVELS WERE 2.3% AND 2.2% IN GC CASES AND CONTROLS, RESPECTIVELY. NO SIGNIFICANT ASSOCIATION WAS FOUND BETWEEN COX-2 METHYLATION AND RISK OF GC (OR, 1.15; 95% CI: 0.70-1.88). HOWEVER, THE TEMPORAL TREND ANALYSIS SHOWED THAT COX-2 METHYLATION LEVELS WERE ELEVATED AT 1-4 YEARS AHEAD OF CLINICAL GC DIAGNOSIS COMPARED WITH THE YEAR OF GC DIAGNOSIS (3.0% VS. 2.2%, P=0.01). FURTHER VALIDATION IN 31 GCS WITH BOTH PRE- AND POST-GC SAMPLES INDICATED THAT COX-2 METHYLATION LEVELS WERE SIGNIFICANTLY DECREASED AT THE YEAR OF GC DIAGNOSIS COMPARED WITH PRE-GC SAMPLES (1.5% VS. 2.5%, P=0.02). NO SIGNIFICANT ASSOCIATION BETWEEN COX-2 METHYLATION AND RISK OF PROGRESSION TO GC WAS FOUND IN SUBJECTS WITH IM (OR, 0.50; 95% CI: 0.18-1.42) OR DYS (OR, 0.70; 95% CI: 0.23-2.18). ADDITIONALLY, WE FOUND THAT ELDER PEOPLE HAD INCREASED RISK OF COX-2 HYPERMETHYLATION (OR, 1.55; 95% CI: 1.02-2.36) AND SUBJECTS WHO EVER INFECTED WITH H. PYLORI HAD DECREASED RISK OF COX-2 HYPERMETHYLATION (OR, 0.54; 95% CI: 0.34-0.88). CONCLUSIONS: COX-2 METHYLATION EXISTS IN BLOOD LEUKOCYTE DNA BUT AT A LOW LEVEL. COX-2 METHYLATION LEVELS IN BLOOD LEUKOCYTE DNA MAY CHANGE DURING GC DEVELOPMENT. 2015 10 4245 38 METHYLATION STATUS OF DDIT3 GENE IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: DNA-DAMAGE-INDUCIBLE TRANSCRIPT 3 (DDIT3), A CANDIDATE TUMOR SUPPRESSOR GENE (TSG), HAS BEEN FOUND INVOLVED IN THE REGULATION OF CELLULAR GROWTH AND DIFFERENTIATION. THE EPIGENETIC CHANGES OF TSGS ARE RECENTLY RECOGNIZED AS AN ABNORMAL MECHANISM CONTRIBUTING TO THE DEVELOPMENT OF CHRONIC MYELOID LEUKEMIA (CML). THE AIM OF THIS STUDY WAS TO INVESTIGATE THE METHYLATION STATUS OF DDIT3 GENE IN CML PATIENTS. METHODS: THE METHYLATION STATUS OF DDIT3 PROMOTER WAS DETECTED IN THE BONE MARROW MONONUCLEAR CELLS FROM 53 PATIENTS WITH CML USING METHYLATION-SPECIFIC PCR (MSP). THE EXPRESSION LEVELS OF DDIT3 AND BCR/ABL TRANSCRIPT WERE DETERMINED BY REAL-TIME QUANTITATIVE PCR (RQ-PCR). CLINICAL DATA OF THESE PATIENTS WERE COLLECTED AND ANALYZED. RESULTS: THE ABERRANT METHYLATION OF DDIT3 GENE PROMOTER WAS FOUND IN 35 OF 53 (66%) CML CASES. CORRELATION WAS NOT FOUND BETWEEN DDIT3 PROMOTER HYPERMETHYLATION AND THE AGE, SEX, HEMOGLOBIN CONCENTRATION, PLATELET COUNTS, CHROMOSOMAL ABNORMALITIES, BCR/ABL TRANSCRIPT, AND STAGING OF CML PATIENTS (P > 0.05), BUT FOUND BETWEEN DDIT3 PROMOTER HYPERMETHYLATION AND WBC COUNTS OF CML CASES (R = 0.781, P < 0.001). THE LEVEL OF DDIT3 TRANSCRIPT IN CML PATIENTS WAS SIGNIFICANTLY LOWER THAN THAT IN CONTROLS (MEDIAN 3.28 VS 19.69, P < 0.001), HOWEVER, THERE WAS NO DIFFERENCE IN THE LEVEL OF DDIT3 TRANSCRIPT BETWEEN METHYLATION-POSITIVE CML CASES (0.05-65.32, MEDIAN 2.13) AND METHYLATION- NEGATIVE CML CASES (0.12-126.04, MEDIAN 3.92) (P > 0.05). CONCLUSION: OUR RESULTS DEMONSTRATE THAT ABERRANT METHYLATION OF DDIT3 OCCURS IN CML FREQUENTLY. 2010 11 5683 31 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 0.05). SERUM H3K4ME1 LEVEL (287.3 VS. 179.7 PG/ML, P < 0.05) SIGNIFICANTLY INCREASED IN HS GROUP OF SS INDIVIDUALS, BUT NOT IN SR INDIVIDUALS. WE FOUND DAILY SALT INTAKE IN SS INDIVIDUALS WAS POSITIVELY CORRELATED WITH SERUM H3K4ME1 (R = 0.322, P = 0.005) AND SET7 (R = 0.340, P = 0.005) LEVELS AFTER ADJUSTING FOR AGE AND GENDER, BUT NOT WITH LSD-1 (R = -0.137, P = 0.251). IN ADDITION, POSITIVE CORRELATION BETWEEN THE SERUM H3K4ME1 LEVEL AND SET7 LEVEL (R = 0.326, P = 0.007) WAS ALSO FOUND IN SS INDIVIDUALS. THESE CORRELATIONS WERE NOT EVIDENT IN SR INDIVIDUALS. CONCLUSION: OUR STUDY INDICATES THAT HIGH SALT DIET INCREASES THE SERUM H3K4ME1 AND SET7 LEVELS IN SS INDIVIDUALS. 2022 13 4378 36 MITOCHONDRIAL DNA COPY NUMBER AND EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS. BACKGROUND: INCREASED MITOCHONDRIAL DNA COPY NUMBER (MTDNACN) IS A BIOLOGIC RESPONSE TO MTDNA DAMAGE AND DYSFUNCTION, PREDICTIVE OF LUNG CANCER RISK. POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) ARE ESTABLISHED LUNG CARCINOGENS AND MAY CAUSE MITOCHONDRIAL TOXICITY. WHETHER PAH EXPOSURE AND PAH-RELATED NUCLEAR DNA (NDNA) GENOTOXIC EFFECTS ARE LINKED WITH INCREASED MTDNACN HAS NEVER BEEN EVALUATED. METHODS: WE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO PAHS ON MTDNACN IN PERIPHERAL BLOOD LYMPHOCYTES (PBLS) OF 46 POLISH MALE NONCURRENT SMOKING COKE-OVEN WORKERS AND 44 MATCHED CONTROLS, WHO WERE PART OF A GROUP OF 94 STUDY INDIVIDUALS EXAMINED IN OUR PREVIOUS WORK. SUBJECTS' PAH EXPOSURE AND GENETIC ALTERATIONS WERE CHARACTERIZED THROUGH MEASURES OF INTERNAL DOSE (URINARY 1-PYRENOL), TARGET DOSE [ANTI-BENZO[A]PYRENE DIOLEPOXIDE (ANTI-BPDE)-DNA ADDUCT], GENETIC INSTABILITY (MICRONUCLEI AND TELOMERE LENGTH), AND DNA METHYLATION (P53 PROMOTER) IN PBLS. MTDNACN (MT/S) WAS MEASURED USING A VALIDATED REAL-TIME PCR METHOD. RESULTS: WORKERS WITH PAH EXPOSURE ABOVE THE MEDIAN VALUE (>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 14 3783 31 INTERFERON-GAMMA PROMOTER HYPOMETHYLATION AND INCREASED EXPRESSION IN CHRONIC PERIODONTITIS. AIM: THE GOAL OF THIS INVESTIGATION WAS TO DETERMINE WHETHER EPIGENETIC MODIFICATIONS IN THE IFNG PROMOTER ARE ASSOCIATED WITH AN INCREASE OF IFNG TRANSCRIPTION IN DIFFERENT STAGES OF PERIODONTAL DISEASES. MATERIALS AND METHODS: DNA WAS EXTRACTED FROM GINGIVAL BIOPSY SAMPLES COLLECTED FROM 47 TOTAL SITES FROM 47 DIFFERENT SUBJECTS: 23 PERIODONTALLY HEALTHY SITES, 12 EXPERIMENTALLY INDUCED GINGIVITIS SITES AND 12 CHRONIC PERIODONTITIS SITES. LEVELS OF DNA METHYLATION WITHIN THE IFNG PROMOTER CONTAINING SIX CPG DINUCLEOTIDES WERE DETERMINED USING PYROSEQUENCING TECHNOLOGY. INTERFERON GAMMA MRNA EXPRESSION WAS ANALYSED BY QUANTITATIVE POLYMERASE CHAIN REACTIONS USING ISOLATED RNA FROM PART OF THE BIOLOGICAL SAMPLES MENTIONED ABOVE. RESULTS: THE METHYLATION LEVEL OF ALL SIX ANALYSED CPG SITES WITHIN THE IFNG PROMOTER REGION IN THE PERIODONTITIS BIOPSIES 52% [INTERQUARTILE RANGE, IQR (43.8%, 63%)] WAS SIGNIFICANTLY LOWER THAN PERIODONTALLY HEALTHY SAMPLES 62% [IQR (51.3%, 74%)], P=0.007 AND GINGIVITIS BIOPSIES 63% [IQR (55%, 74%)], P=0.02. THE TRANSCRIPTIONAL LEVEL OF IFNG IN PERIODONTITIS BIOPSIES WAS 1.96-FOLD AND SIGNIFICANTLY HIGHER THAN TISSUES WITH PERIODONTAL HEALTH (P=0.04). ALTHOUGH THE MRNA LEVEL FROM EXPERIMENTAL GINGIVITIS SAMPLES EXHIBITED AN 8.5-FOLD INCREASE AS COMPARED WITH PERIODONTALLY HEALTHY SAMPLES, NO SIGNIFICANT METHYLATION DIFFERENCE WAS OBSERVED IN EXPERIMENTAL GINGIVITIS SAMPLE. CONCLUSIONS: A HYPOMETHYLATION PROFILE WITHIN IFNG PROMOTER REGION IS RELATED TO AN INCREASE OF IFNG TRANSCRIPTION PRESENT IN THE CHRONIC PERIODONTITIS BIOPSIES, WHILE SUCH AN INCREASE OF IFNG IN EXPERIMENTALLY INDUCED GINGIVITIS SEEMS INDEPENDENT OF PROMOTER METHYLATION ALTERATION. 2010 15 5246 34 PROGNOSTIC SCORE INCLUDING GENE MUTATIONS IN CHRONIC MYELOMONOCYTIC LEUKEMIA. PURPOSE: SEVERAL PROGNOSTIC SCORING SYSTEMS HAVE BEEN PROPOSED FOR CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), A DISEASE IN WHICH SOME GENE MUTATIONS-INCLUDING ASXL1-HAVE BEEN ASSOCIATED WITH POOR PROGNOSIS IN UNIVARIABLE ANALYSES. WE DEVELOPED AND VALIDATED A PROGNOSTIC SCORE FOR OVERALL SURVIVAL (OS) BASED ON MUTATIONAL STATUS AND STANDARD CLINICAL VARIABLES. PATIENTS AND METHODS: WE GENOTYPED ASXL1 AND UP TO 18 OTHER GENES INCLUDING EPIGENETIC (TET2, EZH2, IDH1, IDH2, DNMT3A), SPLICING (SF3B1, SRSF2, ZRSF2, U2AF1), TRANSCRIPTION (RUNX1, NPM1, TP53), AND SIGNALING (NRAS, KRAS, CBL, JAK2, FLT3) REGULATORS IN 312 PATIENTS WITH CMML. GENOTYPES AND CLINICAL VARIABLES WERE INCLUDED IN A MULTIVARIABLE COX MODEL OF OS VALIDATED BY BOOTSTRAPPING. A SCORING SYSTEM WAS DEVELOPED USING REGRESSION COEFFICIENTS FROM THIS MODEL. RESULTS: ASXL1 MUTATIONS (P < .0001) AND, TO A LESSER EXTENT, SRSF2 (P = .03), CBL (P = .003), AND IDH2 (P = .03) MUTATIONS PREDICTED INFERIOR OS IN UNIVARIABLE ANALYSIS. THE RETAINED INDEPENDENT PROGNOSTIC FACTORS INCLUDED ASXL1 MUTATIONS, AGE OLDER THAN 65 YEARS, WBC COUNT GREATER THAN 15 X10(9)/L, PLATELET COUNT LESS THAN 100 X10(9)/L, AND ANEMIA (HEMOGLOBIN < 10 G/DL IN FEMALE PATIENTS, < 11G/DL IN MALE PATIENTS). THE RESULTING FIVE-PARAMETER PROGNOSTIC SCORE DELINEATED THREE GROUPS OF PATIENTS WITH MEDIAN OS NOT REACHED, 38.5 MONTHS, AND 14.4 MONTHS, RESPECTIVELY (P < .0001), AND WAS VALIDATED IN AN INDEPENDENT COHORT OF 165 PATIENTS (P < .0001). CONCLUSION: A NEW PROGNOSTIC SCORE INCLUDING ASXL1 STATUS, AGE, HEMOGLOBIN, WBC, AND PLATELET COUNTS DEFINES THREE GROUPS OF CMML PATIENTS WITH DISTINCT OUTCOMES. BASED ON CONCORDANCE ANALYSIS, THIS SCORE APPEARS MORE DISCRIMINATIVE THAN THOSE BASED SOLELY ON CLINICAL PARAMETERS. 2013 16 4601 32 NDRG2 MRNA LEVELS AND MIR-28-5P AND MIR-650 ACTIVITY IN CHRONIC LYMPHOCYTIC LEUKEMIA. BACKGROUND: NDRG2 IS IDENTIFIED AS A TUMOR SUPPRESSOR GENE IN MANY TUMORS, AND FUNCTIONS IN CELL PROLIFERATION, DIFFERENTIATION AND APOPTOSIS. RECENT DATA INDICATE THAT NDRG2 EXPRESSION IS UP-REGULATED BY TP53. MOREOVER, PROPOSED MECHANISMS OF NDRG2 INACTIVATION INCLUDE EPIGENETIC SILENCING OF THE NDRG2 PROMOTER AND DOWN-REGULATION BY MICRORNAS (MIRNAS). HOWEVER, FEW STUDIES HAVE EVER BEEN DONE ON THE ROLE OF NDRG2 AND THE NDRG2-REGULATING MIRNAS INTERFERENCE IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). METHODS: NDRG2 AND MICRORNAS MRNA LEVELS IN CLL SUBJECTS WERE ASSESSED BY QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QRT-PCR). THE DUAL-LUCIFERASE REPORTER ASSAY WAS PERFORMED TO DETERMINE NDRG2-RELATED MIRNAS. LOW EXPRESSION OF MATURE EXOGENOUS MIRNAS IN CLL CELLS WAS ESTABLISHED BY TRANSIENT TRANSFECTION. NDRG2 PROTEIN LEVELS IN CLL CELLS WERE DETECTED BY WESTERN BLOT. IN ADDITION, FLOW CYTOMETRY WAS CONDUCTED TO EXAMINE THE APOPTOSIS OF CLL CELLS. RESULTS: LOWER EXPRESSION OF NDRG2 WAS FOUND IN THE B-CELLS FROM 102 CLL PATIENTS COMPARED THE 40 NORMAL SUBJECTS (P < 0.001). PATIENTS WITH ADVANCED BINET STAGE (P = 0.001), HIGH LACTATE DEHYDROGENASE (LDH) LEVEL (P = 0.036), UN-MUTATED IMMUNOGLOBULIN HEAVY CHAIN VARIABLE REGION GENE (IGHV) (P = 0.004) AND THOSE WITH P53 ABERRATIONS (P < 0.001) HAD A MARKEDLY LOWER LEVELS OF NDRG2 MRNA. THIS DECREASE WAS ASSOCIATED WITH BRIEFER TIME-TO-TREATMENT (P = 0.001) AND POORER SURVIVAL (P < 0.001). HIGH EXPRESSION OF MIR-28-5P AND MIR-650 WAS ASSOCIATED WITH BINET B/C STAGE (P = 0.044) AND IGHV UN-MUTATED (P = 0.011), AS WELL AS BINET B/C STAGE (P = 0.013) AND P53 ABERRATIONS (P = 0.037), RESPECTIVELY. INHIBITION OF MIR-28-5P OR MIR-650 COULD INDUCE MORE APOPTOSIS IN CLL CELLS WITH GERMLINE TP53. CONCLUSIONS: NDRG2 MRNA LEVELS MIGHT BE A USEFUL PROGNOSTIC VARIABLE FOR PATIENTS OF CLL AND UP-REGULATING NDRG2 TRANSCRIPTION MAY BE A THERAPY APPROACH IN CLL WITHOUT P53 ABERRATIONS. 2018 17 1189 41 CORRELATION BETWEEN GLOBAL METHYLATION LEVEL OF PERIPHERAL BLOOD LEUKOCYTES AND SERUM C REACTIVE PROTEIN LEVEL MODIFIED BY MTHFR POLYMORPHISM: A CROSS-SECTIONAL STUDY. BACKGROUND: CHRONIC INFLAMMATORY CONDITIONS ARE ASSOCIATED WITH HIGHER TUMOR INCIDENCE THROUGH EPIGENETIC AND GENETIC ALTERATIONS. HERE, WE FOCUSED ON AN ASSOCIATION BETWEEN AN INFLAMMATION MARKER, C-REACTIVE-PROTEIN (CRP), AND GLOBAL DNA METHYLATION LEVELS OF PERIPHERAL BLOOD LEUKOCYTES. METHODS: THE SUBJECTS WERE 384 HEALTHY JAPANESE WOMEN ENROLLED AS THE CONTROL GROUP OF A CASE-CONTROL STUDY FOR BREAST CANCER CONDUCTED FROM 2001 TO 2005. GLOBAL DNA METHYLATION WAS QUANTIFIED BY LUMINOMETRIC METHYLATION ASSAY (LUMA). RESULTS: WITH ADJUSTMENT FOR LIFESTYLE-RELATED FACTORS, INCLUDING FOLATE INTAKE, THE GLOBAL DNA METHYLATION LEVEL OF PERIPHERAL BLOOD LEUKOCYTES WAS SIGNIFICANTLY BUT WEAKLY INCREASED BY 0.43% PER QUARTILE CATEGORY FOR CRP (P FOR TREND = 0.010). ESTIMATED METHYLATION LEVELS STRATIFIED BY CRP QUARTILE WERE 70.0%, 70.8%, 71.4%, AND 71.3%, RESPECTIVELY. IN ADDITION, INTERACTION BETWEEN POLYMORPHISM OF MTHFR (RS1801133, KNOWN AS C677T) AND CRP WAS SIGNIFICANT (P FOR INTERACTION = 0.046); THE GLOBAL METHYLATION LEVEL WAS SIGNIFICANTLY INCREASED BY 0.61% PER QUARTILE CATEGORY FOR CRP IN THE CT/TT GROUP (THOSE WITH THE MINOR ALLELE T, P FOR TREND = 0.001), WHEREAS NO ASSOCIATION WAS OBSERVED IN THE CC GROUP (WILD TYPE). CONCLUSIONS: OUR STUDY SUGGESTS THAT CRP CONCENTRATION IS WEAKLY ASSOCIATED WITH GLOBAL DNA METHYLATION LEVEL. HOWEVER, THIS ASSOCIATION WAS OBSERVED MORE CLEARLY IN INDIVIDUALS WITH THE MINOR ALLELE OF THE MTHFR MISSENSE SNP RS1801133. BY ELUCIDATING THE COMPLEX MECHANISM OF THE REGULATION OF DNA METHYLATION BY BOTH ACQUIRED AND GENETIC FACTORS, OUR RESULTS MAY BE IMPORTANT FOR CANCER PREVENTION. 2018 18 713 36 CADMIUM EXPOSURE AND AGE-ASSOCIATED DNA METHYLATION CHANGES IN NON-SMOKING WOMEN FROM NORTHERN THAILAND. DNA METHYLATION CHANGES WITH AGE, AND MAY SERVE AS A BIOMARKER OF AGING. CADMIUM (CD) MODIFIES CELLULAR PROCESSES THAT PROMOTE AGING AND DISRUPTS METHYLATION GLOBALLY. WHETHER CD MODIFIES AGING PROCESSES BY INFLUENCING ESTABLISHMENT OF AGE-ASSOCIATED METHYLATION MARKS IS CURRENTLY UNKNOWN. IN THIS PILOT STUDY, WE CHARACTERIZED METHYLATION PROFILES IN > 450 000 CPG SITES IN 40 NON-SMOKING WOMEN (AGE 40-80) DIFFERENTIALLY EXPOSED TO ENVIRONMENTAL CD FROM THAILAND. BASED ON SPECIFIC GRAVITY ADJUSTED URINARY CD, WE CLASSIFIED THEM AS HIGH (HE) AND LOW (LE) EXPOSED AND AGE-MATCHED WITHIN 5 YEARS. URINARY CD WAS DEFINED AS BELOW 2 MICROG/L IN THE LE GROUP. WE PREDICTED EPIGENETIC AGE (DNAM-AGE) USING TWO PUBLISHED METHODS BY HORVATH AND HANNUM AND EXAMINED THE DIFFERENCE BETWEEN EPIGENETIC AGE AND CHRONOLOGIC AGE (DELTAAGE). WE ASSESSED DIFFERENCES BY CD EXPOSURE USING LINEAR MIXED MODELS ADJUSTED FOR ESTIMATED WHITE BLOOD CELL PROPORTIONS, BMI, AND URINARY CREATININE. WE IDENTIFIED 213 AGE-ASSOCIATED CPG SITES IN OUR POPULATION (P < 10(-4)). COUNTERINTUITIVELY, THE MEAN DELTAAGE WAS SMALLER IN HE VS. LE (HANNUM: 3.6 VS. 7.6 YEARS, P = 0.0093; HORVATH: 2.4 VS. 4.5 YEARS, P = 0.1308). THE CD EXPOSED GROUP WAS ASSOCIATED WITH CHANGES IN METHYLATION (P < 0.05) AT 12, 8, AND 20 AGE-ASSOCIATED SITES IDENTIFIED IN OUR POPULATION, HANNUM, AND HORVATH. FROM THE RESULTS OF THIS PILOT STUDY, ELEVATED CD EXPOSURE IS ASSOCIATED WITH METHYLATION CHANGES AT AGE-ASSOCIATED SITES AND SMALLER DIFFERENCES BETWEEN DNAM-AGE AND CHRONOLOGIC AGE, IN CONTRAST TO EXPECTED AGE-ACCELERATING EFFECTS. CD MAY MODIFY EPIGENETIC AGING, AND BIOMARKERS OF AGING WARRANT FURTHER INVESTIGATION WHEN EXAMINING CD AND ITS RELATIONSHIP WITH CHRONIC DISEASE AND MORTALITY. 2017 19 91 32 A PILOT STUDY EXAMINING THE RELATIONSHIP BETWEEN CHRONIC HEROIN USE AND TELOMERE LENGTH AMONG INDIVIDUALS OF AFRICAN ANCESTRY. BACKGROUND: PRIOR RESEARCH HAS SUGGESTED A POSSIBLE LINK BETWEEN HEROIN USE AND SHORTENED TELOMERE LENGTH (TL), A MARKER OF CELLULAR AGING AND GENOMIC STABILITY. WE SOUGHT TO REPLICATE THESE FINDINGS BY EXAMINING THE RELATIONSHIP BETWEEN TL AND HEROIN USE AMONG INDIVIDUALS OF AFRICAN ANCESTRY. METHODS: THIS CROSS-SECTIONAL STUDY EXAMINED TL AMONG 57 PARTICIPANTS [17.5 % FEMALE; MEAN AGE 48.0 (+/-6.80) YEARS] OF AFRICAN ANCESTRY WITH OPIOID USE DISORDER (OUD) AND A MEAN HEROIN USE DURATION OF 18.2 (+/-10.7) YEARS. QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR) WAS USED TO CALCULATE TL AS THE RATIO BETWEEN TELOMERE REPEAT COPY NUMBER (T) AND A SINGLE-COPY GENE, COPY NUMBER (S). THE PRIMARY DEPENDENT VARIABLE WAS TL (T/S RATIO) MEASURED IN KILOBASE PAIRS. COVARIATES INCLUDED HEROIN USE YEARS AND PERSONALITY TRAITS. USING A HYBRID APPROACH, MULTIPLE LINEAR REGRESSION AND BAYESIAN LINEAR REGRESSION EXAMINED THE ASSOCIATION OF CHRONOLOGICAL AGE, HEROIN USE YEARS AND PERSONALITY TRAITS WITH TL. RESULTS: THE MULTIPLE LINEAR REGRESSION MODEL FIT THE DATA WELL, R(2) = 0.265, F(7,49) = 2.53, P < .026. CHRONOLOGICAL AGE (BETA = -0.36, P = .017), NEUROTICISM (BETA = 0.46, P = .044), AND CONSCIENTIOUSNESS (BETA = 0.52, P = .040) WERE SIGNIFICANT PREDICTORS OF TL. BAYESIAN LINEAR REGRESSION PROVIDED MODERATE SUPPORT FOR THE ALTERNATE HYPOTHESIS THAT CHRONOLOGICAL AGE AND TL ARE ASSOCIATED, BF(10) = 5.77, R(2) = 0.120. THE POSTERIOR SUMMARY OF THE COEFFICIENT WAS M = 0.719 (SD = 0.278, 95 % CREDIBLE INTERVAL [-1.28, -0.163]). CONCLUSIONS: CONTRARY TO PRIOR STUDIES, THESE FINDINGS SUGGEST THAT HEROIN USE DURATION MAY NOT BE SIGNIFICANTLY ASSOCIATED WITH TL AMONG INDIVIDUALS OF AFRICAN ANCESTRY, HIGHLIGHTING THE NEED FOR MORE RIGOROUS RESEARCH TO ELUCIDATE THE COMPLEXITY OF THIS RELATIONSHIP. 2023 20 1956 37 EPIGENETIC AGE IN PERIPHERAL BLOOD AMONG CHILDREN, ADOLESCENT, AND ADULT SURVIVORS OF CHILDHOOD CANCER. IMPORTANCE: CERTAIN CANCER THERAPIES ARE RISK FACTORS FOR EPIGENETIC AGE ACCELERATION (EAA) AMONG SURVIVORS OF CHILDHOOD CANCER, AND EAA IS ASSOCIATED WITH CHRONIC HEALTH CONDITIONS (CHCS). HOWEVER, SMALL NUMBERS OF YOUNGER SURVIVORS (AGED <20 YEARS) PREVIOUSLY EVALUATED HAVE LIMITED THE ABILITY TO CALCULATE EAA AMONG THIS AGE GROUP. OBJECTIVE: TO EVALUATE THE CHANGE RATE OF EPIGENETIC AGE (EA) AND EAA IN YOUNGER COMPARED WITH OLDER SURVIVORS AND THE POSSIBLE ASSOCIATION OF EAA WITH EARLY-ONSET OBESITY (AGED <20 YEARS), SEVERITY/BURDEN OF CHCS, AND LATE MORTALITY (>5 YEARS FROM CANCER DIAGNOSIS). DESIGN, SETTING, AND PARTICIPANTS: STUDY PARTICIPANTS WERE FROM THE ST JUDE LIFETIME COHORT, INITIATED IN 2007 WITH ONGOING FOLLOW-UP. THE PRESENT STUDY WAS CONDUCTED FROM APRIL 17, 2022, TO MARCH 23, 2023. SURVIVORS IN THIS COHORT OF EUROPEAN ANCESTRY WITH DNA METHYLATION DATA WERE INCLUDED. CROSS-SECTIONAL ANNUAL CHANGES IN EA AND EAA WERE COMPARED ACROSS 5 DIFFERENT CHRONOLOGIC AGE GROUPS: AGE 0 TO 9 (CHILDREN), 10 TO 19 (ADOLESCENTS), 20 TO 34 (YOUNGER ADULTS), 35 TO 49 (MIDDLE-AGED ADULTS), AND GREATER THAN OR EQUAL TO 50 (OLDER ADULTS) YEARS. LOGISTIC REGRESSION EVALUATED THE ASSOCIATION BETWEEN EAA AND EARLY-ONSET OBESITY OR SEVERITY/BURDEN OF CHCS. COX PROPORTIONAL HAZARDS REGRESSION ASSESSED THE ASSOCIATION BETWEEN EAA AND LATE MORTALITY. MAIN OUTCOMES AND MEASURES: EARLY-ONSET OBESITY, SEVERITY/BURDEN OF CHCS (GRADED USING THE COMMON TERMINOLOGY CRITERIA FOR ADVERSE EVENTS (GRADE 1, MILD; 2, MODERATE; 3, SEVERE/DISABLING; 4, LIFE-THREATENING) AND WERE COMBINED INTO HIGH VS LOW SEVERITY/BURDEN BASED ON FREQUENCY AND GRADE), AND LATE MORTALITY WERE THE OUTCOMES BASED ON FOLLOW-UP UNTIL APRIL 2020. EXPANDED DNA METHYLATION PROFILING INCREASED THE NUMBER OF SURVIVORS YOUNGER THAN 20 YEARS (N = 690). EPIGENETIC AGE WAS CALCULATED PRIMARILY USING THE LEVINE CLOCK, AND EAA WAS DERIVED FROM LEAST SQUARES REGRESSION OF EA AGAINST CHRONOLOGIC AGE AND WAS STANDARDIZED TO A Z SCORE (LEVINE EEA). RESULTS: AMONG 2846 PARTICIPANTS (MEDIAN AGE, 30.3 [IQR, 9.3-41.5] YEARS; 53% MALES), THE CROSS-SECTIONAL ANNUAL CHANGE IN EA_LEVINE WAS HIGHER IN CHILDREN (1.63 YEARS) AND ADOLESCENTS (1.14 YEARS), AND THE ADJUSTED LEAST-SQUARES MEAN OF LEVINE EEA WAS LOWER IN CHILDREN (-0.22 YEARS) AND OLDER ADULTS (-1.70 YEARS). EACH 1-SD INCREASE IN LEVINE EEA WAS ASSOCIATED WITH INCREASED RISK OF DEVELOPING EARLY-ONSET OBESITY (ODDS RATIO [OR], 1.46; 95% CI, 1.19-1.78), HIGH SEVERITY/BURDEN OF CHCS (OR, 1.13; 95% CI, 1.03-1.24), AND LATE MORTALITY (HAZARD RATIO, 1.75; 95% CI, 1.35-2.26). CONCLUSIONS AND RELEVANCE: THE FINDINGS OF THIS STUDY SUGGEST THAT EAA MEASURED IN CHILDREN AND ADOLESCENT SURVIVORS OF CHILDHOOD CANCER IS ASSOCIATED WITH EARLY-ONSET OBESITY, SEVERITY/BURDEN OF ALL CHCS, AND LATE MORTALITY. EVALUATING EAA MAY HELP IDENTIFY SURVIVORS OF CHILDHOOD CANCER AT INCREASED RISK FOR EARLY-ONSET OBESITY, MORBIDITY IN GENERAL, AND MORTALITY. 2023