1 1737 194 EARLY DETECTION OF ACCELERATED AGING AND CELLULAR DECLINE (AACD): A CONSENSUS STATEMENT. THE CELLULAR HALLMARKS OF ACCELERATED AGING AND THEIR CLINICAL EXPRESSION MAY BE GROUPED USING THE TERMS 'ACCELERATED AGING AND CELLULAR DECLINE' (AACD) AND/OR 'AGE-ASSOCIATED CELLULAR DECLINE'. THIS CONSTRUCT IS DESIGNED TO CAPTURE THE BIOLOGICAL BACKGROUND PREDISPOSING THE DEVELOPMENT OF AGE-RELATED CONDITIONS. BY CLASSIFYING RISK FACTORS, EARLY INDICATORS, AND CLINICAL DIFFERENTIATORS OF AACD THROUGH EXPERT CONSENSUS, THIS STUDY AIMED TO IDENTIFY THE SIGNS, SYMPTOMS, AND MARKERS INDICATIVE OF AACD. IN DOING SO, THIS WORK PAVES THE WAY FOR FUTURE IMPLEMENTATION OF THE AACD CONCEPT IN THE CLINICAL AND RESEARCH SETTINGS. AN INTERDISCIPLINARY PANEL OF EXPERTS WITH CLINICAL AND RESEARCH EXPERTISE WAS SELECTED TO PARTICIPATE IN A VIRTUAL WORKSHOP TO DISCUSS AACD. A MODIFIED NOMINAL GROUP TECHNIQUE WAS USED TO ESTABLISH CONSENSUS AMONG THE GROUP. AN EXTENDED GROUP OF INTERNATIONAL EXPERTS CRITICALLY REVIEWED AN EARLY DRAFT OF THE MANUSCRIPT, AND THEIR FEEDBACK WAS THEN INCORPORATED INTO THE MODEL. EXPERTS IDENTIFIED 13 FACTORS PREDISPOSING TO OR CLINICALLY MANIFESTING AACD. AMONG THESE, CHRONIC DISEASES, OBESITY, AND UNFAVORABLE GENETIC BACKGROUND WERE CONSIDERED AS THE MOST IMPORTANT. THERE WAS A CONSENSUS THAT A GRADUAL AND NONSPECIFIC DEVELOPMENT OFTEN CHARACTERIZES AACD, MAKING ITS CLINICAL DETECTION POTENTIALLY CHALLENGING. IN ADDITION, SIGNS AND SYMPTOMS MIGHT HAVE MULTIFACTORIAL CAUSES AND OVERLAPPING ORIGINS, SUCH AS GENETIC AND EPIGENETIC PREDISPOSITIONS. AS A RESULT, AN INITIAL CHECKLIST WAS OUTLINED, LISTING CLINICAL FACTORS OF SPECIAL RELEVANCE (E.G., FATIGUE, LOW QUALITY OF SLEEP, AND LOW MOOD) TO REPRESENT EARLY MANIFESTATIONS OF THE ORGANISM'S EXHAUSTION, WHICH ARE ALSO FREQUENTLY NEGLECTED IN THE CLINICAL SETTING. DIFFERENTIATING AACD FROM OTHER CONDITIONS IS ESSENTIAL. THE USE OF A COMBINATION OF BIOMARKERS WAS PROPOSED AS A VIABLE METHOD IN A TWO-STEP PROCESS OF DIFFERENTIATION: 1) IDENTIFICATION OF EARLY AACD CLINICAL INDICATORS, FOLLOWED BY 2) SYMPTOM AND BIOMARKER CONFIRMATION WITH A FOCUS ON SYSTEM DOMAINS (TO BE POTENTIALLY TARGETED BY FUTURE SPECIFIC INTERVENTIONS). ALTHOUGH THE AACD CONSTRUCT IS NOT YET READY FOR ROUTINE USE IN CLINICAL PRACTICE, ITS OPERATIONALIZATION MAY SUPPORT THE EARLY IDENTIFICATION OF AGE-RELATED CONDITIONS (WHEN THIS MIGHT STILL BE AMENABLE TO REVERSION) AND ALSO ENCOURAGE PREVENTATIVE INTERVENTIONS. FURTHER INVESTIGATION IS NEEDED TO ESTABLISH SPECIFIC BIOMARKERS THAT CONFIRM INDEPENDENT RISK FACTORS FOR AACD AND PROVIDE A MORE DEFINITIVE STRUCTURE TO THE CONCEPT OF AACD (AND AGE-ASSOCIATED CELLULAR DECLINE). 2021 2 70 33 A METHOD TO DETECT DIFFERENTIALLY METHYLATED LOCI WITH NEXT-GENERATION SEQUENCING. EPIGENETIC CHANGES, ESPECIALLY DNA METHYLATION AT CPG LOCI HAVE IMPORTANT IMPLICATIONS IN CANCER AND OTHER COMPLEX DISEASES. WITH THE DEVELOPMENT OF NEXT-GENERATION SEQUENCING (NGS), IT IS FEASIBLE TO GENERATE DATA TO INTERROGATE THE DIFFERENCE IN METHYLATION STATUS FOR GENOME-WIDE LOCI USING CASE-CONTROL DESIGN. HOWEVER, A PROPER AND EFFICIENT STATISTICAL TEST IS LACKING. THERE ARE SEVERAL CHALLENGES. FIRST, UNLIKE METHYLATION EXPERIMENTS USING MICROARRAYS, WHERE THERE IS ONE MEASURE OF METHYLATION FOR ONE INDIVIDUAL AT A PARTICULAR CPG SITE, HERE WE HAVE THE COUNTS OF METHYLATION ALLELE AND UNMETHYLATION ALLELE FOR EACH INDIVIDUAL. SECOND, DUE TO THE NATURE OF SAMPLE PREPARATION, THE MEASURED METHYLATION REFLECTS THE METHYLATION STATUS OF A MIXTURE OF CELLS INVOLVED IN SAMPLE PREPARATION. THEREFORE, THE UNDERLYING DISTRIBUTION OF THE MEASURED METHYLATION LEVEL IS UNKNOWN, AND A ROBUST TEST IS MORE DESIRABLE THAN PARAMETRIC APPROACH. THIRD, CURRENTLY NGS MEASURES METHYLATION AT OVER 2 MILLION CPG SITES. ANY STATISTICAL TESTS HAVE TO BE COMPUTATIONALLY EFFICIENT IN ORDER TO BE APPLIED TO THE NGS DATA. TAKING THESE CHALLENGES INTO ACCOUNT, WE PROPOSE A TEST FOR DIFFERENTIAL METHYLATION BASED ON CLUSTERED DATA ANALYSIS BY MODELING THE METHYLATION COUNTS. WE PERFORMED SIMULATIONS TO SHOW THAT IT IS ROBUST UNDER SEVERAL DISTRIBUTIONS FOR THE MEASURED METHYLATION LEVELS. IT HAS GOOD POWER AND IS COMPUTATIONALLY EFFICIENT. FINALLY, WE APPLY THE TEST TO OUR NGS DATA ON CHRONIC LYMPHOCYTIC LEUKEMIA. THE RESULTS INDICATE THAT IT IS A PROMISING AND PRACTICAL TEST. 2013 3 437 36 ANTIGEN RECEPTOR STEREOTYPY IN CHRONIC LYMPHOCYTIC LEUKEMIA. THE DISCOVERY OF ALMOST IDENTICAL OR 'STEREOTYPED' B-CELL RECEPTOR IMMUNOGLOBULINS (BCR IG) AMONG UNRELATED PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CEMENTED THE IDEA OF ANTIGEN SELECTION IN DISEASE ONTOGENY AND EVOLUTION. THE SYSTEMATIC ANALYSIS OF THE STEREOTYPY PHENOMENON IN CLL REVEALED THAT AROUND ONE-THIRD OF CLL PATIENTS MAY BE GROUPED INTO SUBSETS BASED ON SHARED SEQUENCE MOTIFS WITHIN THE VARIABLE HEAVY COMPLEMENTARITY DETERMINING REGION 3. STEREOTYPED SUBSETS DISPLAY A STRIKINGLY SIMILAR BIOLOGY OF THE LEUKEMIC CLONES, REFERRING TO MANY DIFFERENT LEVELS, FROM THE IMMUNOGENETIC AND GENETIC AND EXTENDING TO THE EPIGENETIC AND FUNCTIONAL LEVELS. EVEN MORE IMPORTANTLY, THE HOMOGENEITY OF STEREOTYPED SUBSETS HAS CLINICAL CONSEQUENCES AS PATIENTS ASSIGNED TO THE SAME STEREOTYPED SUBSET GENERALLY EXHIBIT AN OVERALL SIMILAR DISEASE COURSE AND OUTCOME. IN OTHER WORDS, STEREOTYPY-BASED PATIENT CLASSIFICATION OF CLL HAS ALREADY PROVIDED A MORE COMPARTMENTALIZED VIEW OF THIS OTHERWISE HETEROGENEOUS DISEASE AND CAN ASSIST IN REFINING PROGNOSTICATION MODELS. WHILE THIS IS RELEVANT ONLY FOR THE ONE-THIRD OF CASES EXPRESSING STEREOTYPED BCR IG; IN PRINCIPLE, HOWEVER, THE FINDINGS FROM FURTHER ANALYSIS OF THE STEREOTYPED SUBSETS MAY ALSO CONTRIBUTE TOWARDS IMPROVED UNDERSTANDING OF THE REMAINING NON-STEREOTYPED FRACTION OF CLL PATIENTS. 2017 4 5882 40 SYSTEMATIC REVIEW OF LUNG FUNCTION AND COPD WITH PERIPHERAL BLOOD DNA METHYLATION IN POPULATION BASED STUDIES. BACKGROUND: EPIGENETIC VARIATIONS IN PERIPHERAL BLOOD HAVE POTENTIAL AS BIOMARKERS FOR DISEASE. THIS SYSTEMATIC REVIEW ASSESSES THE ASSOCIATION OF LUNG FUNCTION AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) WITH DNA METHYLATION PROFILES IN PERIPHERAL BLOOD FROM POPULATION-BASED STUDIES. METHODS: ONLINE DATABASES MEDLINE, EMBASE, AND WEB OF SCIENCE WERE SEARCHED. GOOGLE SCHOLAR WAS SEARCHED TO IDENTIFY GREY LITERATURE. AFTER REMOVING DUPLICATE ARTICLES, 1155 ARTICLES WERE INDEPENDENTLY SCREENED BY TWO INVESTIGATORS. PEER REVIEWED REPORTS ON POPULATION-BASED STUDIES THAT EXAMINED PERIPHERAL BLOOD DNA METHYLATION IN PARTICIPANTS WITH MEASURED LUNG FUNCTION (FEV1, FEV1/FVC RATIO) OR KNOWN COPD STATUS WERE SELECTED FOR FULL-TEXT REVIEW. SIX ARTICLES WERE SUITABLE FOR INCLUSION. INFORMATION REGARDING STUDY CHARACTERISTICS, DESIGNS, METHODOLOGIES AND CONCLUSIONS WAS EXTRACTED. A NARRATIVE SYNTHESIS WAS PERFORMED BASED ON PUBLISHED RESULTS. RESULTS: THREE OF THE SIX ARTICLES ASSESSED THE ASSOCIATION OF COPD WITH DNA METHYLATION, AND TWO OF THESE ALSO INCLUDED ASSOCIATIONS WITH LUNG FUNCTION. OVERALL, FIVE REPORTS EXAMINED THE ASSOCIATION OF LUNG FUNCTION WITH DNA METHYLATION PROFILES. FIVE OF THE SIX ARTICLES REPORTED 'SIGNIFICANT' RESULTS. HOWEVER, NO CONSISTENT CPG SITES WERE IDENTIFIED ACROSS STUDIES FOR COPD STATUS OR LUNG FUNCTION VALUES. CONCLUSIONS: DNA METHYLATION PATTERNS IN PERIPHERAL BLOOD FROM INDIVIDUALS WITH REDUCED LUNG FUNCTION OR COPD MAY BE DIFFERENT TO THOSE IN PEOPLE WITH NORMAL LUNG FUNCTION. HOWEVER, THIS SYSTEMATIC REVIEW DID NOT FIND ANY CONSISTENT ASSOCIATIONS OF LUNG FUNCTION OR COPD WITH DIFFERENTIALLY METHYLATED CPG SITES. LARGE STUDIES WITH A LONGITUDINAL DESIGN TO ADDRESS REVERSE CAUSALITY MAY PROVE A MORE FRUITFUL AREA OF RESEARCH. TRIAL REGISTRATION: PROSPERO 2016: CRD42016037352 . 2017 5 2643 31 EPIGENOMIC ASSOCIATION ANALYSIS IDENTIFIES SMOKING-RELATED DNA METHYLATION SITES IN AFRICAN AMERICANS. CIGARETTE SMOKING IS AN ENVIRONMENTAL RISK FACTOR FOR MANY CHRONIC DISEASES, AND DISEASE RISK CAN OFTEN BE MANAGED BY SMOKING CONTROL. SMOKING CAN INDUCE CELLULAR AND MOLECULAR CHANGES, INCLUDING EPIGENETIC MODIFICATION, BUT THE SHORT- AND LONG-TERM EPIGENETIC MODIFICATIONS CAUSED BY CIGARETTE SMOKING AT THE GENE LEVEL HAVE NOT BEEN WELL UNDERSTOOD. RECENT STUDIES HAVE IDENTIFIED SMOKING-RELATED DNA METHYLATION (DNAM) SITES IN CAUCASIANS. TO DETERMINE WHETHER THE SAME DNAM SITES ASSOCIATE WITH SMOKING IN AFRICAN AMERICANS, AND TO IDENTIFY NOVEL SMOKING-RELATED DNAM SITES, WE CONDUCTED A METHYLOME-WIDE ASSOCIATION STUDY OF CIGARETTE SMOKING USING A DISCOVERY SAMPLE OF 972 AFRICAN AMERICANS, AND A REPLICATION SAMPLE OF 239 AFRICAN AMERICANS WITH TWO ARRAY-BASED METHODS. AMONG 15 DNAM SITES SIGNIFICANTLY ASSOCIATED WITH SMOKING AFTER CORRECTION FOR MULTIPLE TESTING IN OUR DISCOVERY SAMPLE, 5 DNAM SITES ARE REPLICATED IN AN INDEPENDENT COHORT, AND 14 SITES IN THE REPLICATION SAMPLE HAVE EFFECTS IN THE SAME DIRECTION AS IN THE DISCOVERY SAMPLE. THE TOP TWO SMOKING-RELATED DNAM SITES IN F2RL3 (FACTOR II RECEPTOR-LIKE 3) AND GPR15 (G-PROTEIN-COUPLED RECEPTOR 15) OBSERVED IN AFRICAN AMERICANS ARE CONSISTENT WITH PREVIOUS FINDINGS IN CAUCASIANS. THE ASSOCIATIONS BETWEEN THE REPLICATED DNAM SITES AND SMOKING REMAIN SIGNIFICANT AFTER ADJUSTING FOR GENETIC BACKGROUND. DESPITE THE DISTINCT GENETIC BACKGROUND BETWEEN AFRICAN AMERICANS AND CAUCASIANS, THE DNAM FROM THE TWO ETHNIC GROUPS SHARES COMMON ASSOCIATIONS WITH CIGARETTE SMOKING, WHICH SUGGESTS A COMMON MOLECULAR MECHANISM OF EPIGENETIC MODIFICATION INFLUENCED BY ENVIRONMENTAL EXPOSURE. 2013 6 3309 39 HIGHER GENE EXPRESSION VARIABILITY IN THE MORE AGGRESSIVE SUBTYPE OF CHRONIC LYMPHOCYTIC LEUKEMIA. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) PRESENTS TWO SUBTYPES WHICH HAVE DRASTICALLY DIFFERENT CLINICAL OUTCOMES, IGVH MUTATED (M-CLL) AND IGVH UNMUTATED (U-CLL). SO FAR, THESE TWO SUBTYPES ARE NOT ASSOCIATED TO CLEAR DIFFERENCES IN GENE EXPRESSION PROFILES. INTERESTINGLY, RECENT RESULTS HAVE HIGHLIGHTED IMPORTANT ROLES FOR HETEROGENEITY, BOTH AT THE GENETIC AND AT THE EPIGENETIC LEVEL IN CLL PROGRESSION. METHODS: WE ANALYZED GENE EXPRESSION DATA OF TWO LARGE COHORTS OF CLL PATIENTS AND QUANTIFIED EXPRESSION VARIABILITY ACROSS INDIVIDUALS TO INVESTIGATE DIFFERENCES BETWEEN THE TWO SUBTYPES USING DIFFERENT MEASURES AND STATISTICAL TESTS. FUNCTIONAL SIGNIFICANCE WAS EXPLORED BY PATHWAY ENRICHMENT AND NETWORK ANALYSES. FURTHERMORE, WE IMPLEMENTED A RANDOM FOREST APPROACH BASED ON EXPRESSION VARIABILITY TO CLASSIFY PATIENTS INTO DISEASE SUBTYPES. RESULTS: WE FOUND THAT U-CLL, THE MORE AGGRESSIVE TYPE OF THE DISEASE, SHOWS SIGNIFICANTLY INCREASED VARIABILITY OF GENE EXPRESSION ACROSS PATIENTS AND THAT, OVERALL, GENES THAT SHOW HIGHER VARIABILITY IN THE AGGRESSIVE SUBTYPE ARE RELATED TO CELL CYCLE, DEVELOPMENT AND INTER-CELLULAR COMMUNICATION. THESE FUNCTIONS INDICATE A POTENTIAL RELATION BETWEEN GENE EXPRESSION VARIABILITY AND THE FASTER PROGRESSION OF THIS CLL SUBTYPE. FINALLY, A CLASSIFIER BASED ON GENE EXPRESSION VARIABILITY WAS ABLE TO CORRECTLY PREDICT THE DISEASE SUBTYPE OF CLL PATIENTS. CONCLUSIONS: THERE ARE STRONG RELATIONS BETWEEN GENE EXPRESSION VARIABILITY AND DISEASE SUBTYPE LINKING SIGNIFICANTLY INCREASED EXPRESSION VARIABILITY TO PHENOTYPES SUCH AS AGGRESSIVENESS AND RESISTANCE TO THERAPY IN CLL. 2015 7 3901 39 LEAD (PB) AND NEURODEVELOPMENT: A REVIEW ON EXPOSURE AND BIOMARKERS OF EFFECT (BDNF, HDL) AND SUSCEPTIBILITY. LEAD (PB) IS A UBIQUITOUS ENVIRONMENTAL POLLUTANT AND A POTENT TOXIC COMPOUND. HUMANS ARE EXPOSED TO PB THROUGH INHALATION, INGESTION, AND SKIN CONTACT VIA FOOD, WATER, TOBACCO SMOKE, AIR, DUST, AND SOIL. PB ACCUMULATES IN BONES, BRAIN, LIVER AND KIDNEY. FETAL EXPOSURE OCCURS VIA TRANSPLACENTAL TRANSMISSION. THE MOST CRITICAL HEALTH EFFECTS ARE DEVELOPMENTAL NEUROTOXICITY IN INFANTS AND CARDIOVASCULAR EFFECTS AND NEPHROTOXICITY IN ADULTS. PB EXPOSURE HAS BEEN STEADILY DECREASING OVER THE PAST DECADES, BUT THERE ARE FEW RECENT EXPOSURE DATA FROM THE GENERAL EUROPEAN POPULATION; MOREOVER, NO SAFE PB LIMIT HAS BEEN SET. SENSITIVE BIOMARKERS OF EXPOSURE, EFFECT AND SUSCEPTIBILITY, THAT RELIABLY AND TIMELY INDICATE PB-ASSOCIATED TOXICITY ARE REQUIRED TO ASSESS HUMAN EXPOSURE-HEALTH RELATIONSHIPS IN A SITUATION OF LOW TO MODERATE EXPOSURE. THEREFORE, A SYSTEMATIC LITERATURE REVIEW BASED ON PUBMED ENTRIES PUBLISHED BEFORE JULY 2019 THAT ADDRESSED PB EXPOSURE AND BIOMARKERS OF EFFECT AND SUSCEPTIBILITY, NEURODEVELOPMENTAL TOXICITY, EPIGENETIC MODIFICATIONS, AND TRANSCRIPTOMICS WAS CONDUCTED. FINALLY INCLUDED WERE 58 ORIGINAL PAPERS ON PB EXPOSURE AND 17 STUDIES ON BIOMARKERS. THE BIOMARKERS THAT ARE LINKED TO PB EXPOSURE AND NEURODEVELOPMENT WERE GROUPED INTO EFFECT BIOMARKERS (SERUM BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) AND SERUM/SALIVA CORTISOL), SUSCEPTIBILITY MARKERS (EPIGENETIC MARKERS AND GENE SEQUENCE VARIANTS) AND OTHER BIOMARKERS (SERUM HIGH-DENSITY LIPOPROTEIN (HDL), MATERNAL IRON (FE) AND CALCIUM (CA) STATUS). SERUM BDNF AND PLASMA HDL ARE POTENTIAL CANDIDATES TO BE FURTHER VALIDATED AS EFFECT MARKERS FOR ROUTINE USE IN HBM STUDIES OF PB, COMPLEMENTED BY MARKERS OF FE AND CA STATUS TO ALSO ADDRESS NUTRITIONAL INTERACTIONS RELATED TO NEURODEVELOPMENTAL DISORDERS. FOR SEVERAL MARKERS, A CAUSAL RELATIONSHIP WITH PB-INDUCED NEURODEVELOPMENTAL TOXICITY IS LIKELY. RESULTS ON BDNF ARE DISCUSSED IN RELATION TO ADVERSE OUTCOME PATHWAY (AOP) 13 ("CHRONIC BINDING OF ANTAGONIST TO N-METHYL-D-ASPARTATE RECEPTORS (NMDARS) DURING BRAIN DEVELOPMENT INDUCES IMPAIRMENT OF LEARNING AND MEMORY ABILITIES") OF THE AOP-WIKI. FURTHER STUDIES ARE NEEDED TO VALIDATE SENSITIVE, RELIABLE, AND TIMELY EFFECT BIOMARKERS, ESPECIALLY FOR LOW TO MODERATE PB EXPOSURE SCENARIOS. 2021 8 2622 39 EPIGENOME-WIDE ASSOCIATION STUDIES IN ASTHMA: A SYSTEMATIC REVIEW. OBJECTIVE: ASTHMA IS A COMMON CHRONIC RESPIRATORY AIRWAY DISEASE INFLUENCED BY ENVIRONMENTAL FACTORS AND POSSIBLY THEIR INTERACTION WITH THE HUMAN GENOME CAUSING EPIGENETIC CHANGES. EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) HAVE MAINLY INVESTIGATED DNA METHYLATION AND ITS ASSOCIATION WITH DISEASE OR TRAITS, EXPOSURE FACTORS OR GENE EXPRESSION. THIS SYSTEMATIC REVIEW AIMED TO IDENTIFY ALL EWAS ASSESSING DIFFERENTIALLY METHYLATED SITES ASSOCIATED WITH ASTHMA IN HUMANS. DESIGN: STRUCTURED SYSTEMATIC LITERATURE SEARCH FOLLOWING PRISMA GUIDELINES, NEWCASTLE-OTTAWA SCALE (NOS) FOR COHORT STUDIES WAS USED FOR BIAS ASSESSMENT. DATA SOURCES: WE SEARCHED PUBMED AND EMBASE DATABASES FROM 2005 TO 2019. ELIGIBILITY CRITERIA: EPIGENOME-WIDE ASSOCIATION STUDIES TESTING ASSOCIATION BETWEEN DIFFERENTIAL METHYLATION AND ASTHMA IN HUMANS. RESULTS: OVERALL, WE IDENTIFIED 16 EWAS STUDIES COMPLYING WITH OUR SEARCH CRITERIA. TWELVE STUDIES WERE CONDUCTED ON CHILDREN, AND 10 WERE CONDUCTED ON SAMPLE SIZES <150 SUBJECTS. FOUR HUNDRED AND NINETEEN CPGS WERE REPORTED IN CHILDREN STUDIES AFTER CORRECTION FOR MULTIPLE TESTING. IN THE ADULT STUDIES, THOUSANDS OF DIFFERENTIALLY METHYLATED SITES WERE IDENTIFIED. DIFFERENTIAL METHYLATION IN INFLAMMATORY-RELATED GENES CORRELATED WITH HIGHER LEVELS OF GENE EXPRESSIONS OF INFLAMMATORY MODULATORS IN ASTHMA. DIFFERENTIALLY METHYLATED GENES ASSOCIATED WITH ASTHMA INCLUDED SMAD3, SERPINC1, PROK1, IL13, RUNX3 AND TIGIT. FORTY-ONE CPGS WERE REPLICATED AT LEAST ONCE IN BLOOD SAMPLES, AND 28 CPGS WERE REPLICATED IN NASAL SAMPLES. CONCLUSION: ALTHOUGH MANY DIFFERENTIALLY METHYLATED CPGS IN GENES KNOWN TO BE INVOLVED IN ASTHMA HAVE BEEN IDENTIFIED IN EWAS TO DATE, WE CONCLUDE THAT FURTHER STUDIES OF LARGER SAMPLE SIZES AND ANALYSES OF DIFFERENTIAL METHYLATION BETWEEN DIFFERENT PHENOTYPES ARE NEEDED IN ORDER TO COMPREHENSIVELY EVALUATE THE ROLE OF EPIGENETIC FACTORS IN THE PATHOPHYSIOLOGY AND HETEROGENEITY OF ASTHMA, AND THE POTENTIAL CLINICAL UTILITY TO PREDICT OR CLASSIFY PATIENTS WITH ASTHMA. 2019 9 311 39 ALCOHOL AND THE METHYLOME: DESIGN AND ANALYSIS CONSIDERATIONS FOR RESEARCH USING HUMAN SAMPLES. BACKGROUND: A GROWING NUMBER OF STUDIES IN HUMAN SAMPLES HAVE SOUGHT TO DETERMINE WHETHER CHRONIC ALCOHOL USE AND ALCOHOL USE DISORDERS (AUDS) MAY BE ASSOCIATED WITH EPIGENETIC FACTORS, SUCH AS DNA METHYLATION. WE REVIEW THE EXTANT LITERATURE IN LIGHT OF SOME OF THE CHALLENGES THAT CURRENTLY AFFECT THE DESIGN AND INTERPRETATION OF EPIGENETIC RESEARCH IN HUMAN SAMPLES. METHOD: A LITERATURE SEARCH WAS USED TO IDENTIFY STUDIES THAT HAVE EXAMINED DNA METHYLATION IN RELATION TO ALCOHOL USE OR AUDS IN HUMAN SAMPLES (THROUGH JULY 2013). A TOTAL OF 22 STUDIES WERE IDENTIFIED. RESULTS: ASSOCIATIONS WITH QUANTITATIVE OR DIAGNOSTIC PHENOTYPES OF ALCOHOL USE OR AUDS HAVE BEEN REPORTED FOR SEVERAL GENES. HOWEVER, ALL STUDIES TO DATE HAVE RELIED ON RELATIVELY SMALL SAMPLES AND CROSS-SECTIONAL STUDY DESIGNS. ADDITIONALLY, ATTEMPTS TO REPLICATE RESULTS HAVE BEEN RARE. MORE GENERALLY, RESEARCH PROGRESS IS HAMPERED BY SEVERAL ISSUES, INCLUDING LIMITATIONS OF THE TECHNOLOGIES USED TO ASSESS DNA METHYLATION, TISSUE- AND CELL-SPECIFICITY OF METHYLATION PATTERNS, THE DIFFICULTIES OF RELATING OBSERVED METHYLATION DIFFERENCES AT A GIVEN LOCUS TO A FUNCTIONAL EFFECT, AND LIMITED KNOWLEDGE ABOUT THE MOLECULAR MECHANISMS UNDERLYING THE EFFECTS OF ALCOHOL ON DNA METHYLATION. CONCLUSIONS: ALTHOUGH WE SHARE THE OPTIMISM THAT EPIGENETICS MAY LEAD TO NEW INSIGHTS INTO THE ETIOLOGY AND PATHOPHYSIOLOGY OF AUDS, THE METHODOLOGICAL AND SCIENTIFIC CHALLENGES ASSOCIATED WITH CONDUCTING METHYLOMIC RESEARCH IN HUMAN SAMPLES NEED TO BE CAREFULLY CONSIDERED WHEN DESIGNING AND EVALUATING SUCH STUDIES. 2013 10 837 57 CHEMICALLY INDUCED RENAL TUBULE TUMORS IN THE LABORATORY RAT AND MOUSE: REVIEW OF THE NCI/NTP DATABASE AND CATEGORIZATION OF RENAL CARCINOGENS BASED ON MECHANISTIC INFORMATION. THE INCIDENCE OF RENAL TUBULE CARCINOGENESIS IN MALE AND FEMALE RATS OR MICE WITH 69 CHEMICALS FROM THE 513 BIOASSAYS CONDUCTED TO DATE BY THE NCI/NTP HAS BEEN COLLATED, THE CHEMICALS CATEGORIZED, AND THE RELATIONSHIP BETWEEN CARCINOGENESIS AND RENAL TUBULE HYPERPLASIA AND EXACERBATION OF THE SPONTANEOUS, AGE-RELATED RODENT DISEASE CHRONIC PROGRESSIVE NEPHROPATHY (CPN) EXAMINED. WHERE INFORMATION ON MECHANISM OR MODE OF ACTION EXISTS, THE CHEMICALS HAVE BEEN CATEGORIZED BASED ON THEIR ABILITY TO DIRECTLY OR INDIRECTLY INTERACT WITH RENAL DNA, OR ON THEIR ACTIVITY VIA EPIGENETIC PATHWAYS INVOLVING EITHER DIRECT OR INDIRECT CYTOTOXICITY WITH REGENERATIVE HYPERPLASIA, OR EXACERBATION OF CPN. NINE CHEMICALS WERE IDENTIFIED AS DIRECTLY INTERACTING WITH DNA, WITH SIX OF THESE PRODUCING RENAL TUBULE TUMORS AT HIGH INCIDENCE IN RATS OF BOTH SEXES, AND IN SOME CASES ALSO IN MICE. OCHRATOXIN A WAS THE MOST POTENT COMPOUND IN THIS GROUP, PRODUCING A HIGH TUMOR INCIDENCE AT VERY LOW DOSES, OFTEN WITH METASTASIS. THREE CHEMICALS WERE DISCUSSED IN THE CONTEXT OF INDIRECT DNA DAMAGE MEDIATED BY AN OXIDATIVE FREE RADICAL MECHANISM, ONE OF THESE BEING FROM THE NTP DATABASE. A THIRD CATEGORY INCLUDED FOUR CHEMICALS THAT HAD THE POTENTIAL TO CAUSE DNA DAMAGE FOLLOWING CONJUGATION WITH GLUTATHIONE AND SUBSEQUENT ENZYMATIC ACTIVATION TO A REACTIVE SPECIES, USUALLY A THIOL-CONTAINING ENTITY. TWO CHEMICALS WERE ALLOCATED INTO THE CATEGORY INVOLVING A DIRECT CYTOTOXIC ACTION ON THE RENAL TUBULE FOLLOWED BY SUSTAINED COMPENSATORY CELL PROLIFERATION, WHILE NINE WERE INCLUDED IN A GROUP WHERE THE CELL LOSS AND SUSTAINED INCREASE IN RENAL TUBULE CELL TURNOVER WERE DEPENDENT ON LYSOSOMAL ACCUMULATION OF THE MALE RAT-SPECIFIC PROTEIN, ALPHA2MU-GLOBULIN. IN A SIXTH CATEGORY, MORPHOLOGIC EVIDENCE ON TWO CHEMICALS INDICATED THAT THE RENAL TUMORS WERE A CONSEQUENCE OF EXACERBATED CPN. FOR THE REMAINING CHEMICALS, THERE WERE NO PERTINENT DATA ENABLING ASSIGNMENT TO A MECHANISTIC CATEGORY. ACCORDINGLY, THESE CHEMICALS, ACTING THROUGH AN AS YET UNKNOWN MECHANISM, WERE GROUPED AS EITHER BEING ASSOCIATED WITH AN ENHANCEMENT OF CPN (CATEGORY 7, 16 CHEMICALS), OR NOT ASSOCIATED WITH ENHANCED CPN (CATEGORY 8, 4 CHEMICALS). A NINTH CATEGORY DEALT WITH 11 CHEMICALS THAT WERE REGARDED AS PRODUCING INCREASES IN RENAL TUBULE TUMORS THAT DID NOT REACH STATISTICAL SIGNIFICANCE. A 10TH CATEGORY DISCUSSED 6 CHEMICALS THAT INDUCED RENAL TUMORS IN MICE BUT NOT IN RATS, PLUS 8 CHEMICALS THAT PRODUCED A LOW INCIDENCE OF RENAL TUBULE TUMORS IN MICE THAT DID NOT REACH STATISTICAL SIGNIFICANCE. AS MORE MECHANISTIC DATA ARE GENERATED, SOME CHEMICALS WILL INEVITABLY BE PLACED IN DIFFERENT GROUPS, PARTICULARLY THOSE FROM CATEGORIES 7 AND 8. A LARGE NUMBER OF CHEMICALS IN THE SERIES EXACERBATED CPN, BUT THOSE IN CATEGORY 7 ESPECIALLY MAY BE CANDIDATES FOR INCLUSION IN CATEGORY 6 WHEN FURTHER INFORMATION IS GLEANED FROM THE RELEVANT NTP STUDIES. ALSO, NEW DATA ON SPECIFIC CHEMICALS WILL PROBABLY EXPAND CATEGORY 5 AS CYTOTOXICITY AND CELL REGENERATION ARE IDENTIFIED AS OBLIGATORY STEPS IN RENAL CARCINOGENESIS IN MORE CASES. ADDITIONAL CONFIRMATORY OUTCOMES ARISING FROM THIS REVIEW ARE THAT METASTASES FROM RENAL TUBULE TUMORS, WHILE ENCOUNTERED WITH CHEMICALS CAUSING DNA DAMAGE, ARE RARE WITH THOSE ACTING THROUGH AN EPIGENETIC PATHWAY, WITH THE EXCEPTION BEING FUMONISIN B1; THAT MALE RATS AND MICE ARE GENERALLY MORE SUSCEPTIBLE THAN FEMALE RATS AND MICE TO CHEMICAL INDUCTION OF RENAL TUBULE TUMORS; AND THAT A BACKGROUND OF ATYPICAL TUBULE HYPERPLASIA IS A USEFUL INDICATOR REFLECTING A CHEMICALLY ASSOCIATED RENAL TUBULE TUMOR RESPONSE. WITH RESPECT TO RENAL TUBULE TUMORS AND HUMAN RISK ASSESSMENT, CHEMICALS IN CATEGORIES 1 AND 2, AND POSSIBLY 3, WOULD CURRENTLY BE JUDGED BY LINEAR DEFAULT METHODS; CHEMICALS IN CATEGORY 4 (AND PROBABLY SOME IN CATEGORY 3) AS EXHIBITING A THRESHOLD OF ACTIVITY WARRANTING THE BENCHMARK APPROACH; AND THOSE IN CATEGORIES 5 AND 6 AS REPRESENTING MECHANISMS THAT HAVE NO RELEVANCE FOR EXTRAPOLATION TO HUMANS. 2004 11 1450 37 DISAGREEMENT BETWEEN TWO COMMON BIOMARKERS OF GLOBAL DNA METHYLATION. BACKGROUND: THE QUANTIFICATION OF GLOBAL DNA METHYLATION HAS BEEN ESTABLISHED IN EPIGENETIC SCREENING. AS MORE PRACTICABLE ALTERNATIVES TO THE HPLC-BASED GOLD STANDARD, THE METHYLATION ANALYSIS OF CPG ISLANDS IN REPEATABLE ELEMENTS (LINE-1) AND THE LUMINOMETRIC METHYLATION ASSAY (LUMA) OF OVERALL 5-METHYLCYTOSINE CONTENT IN "CCGG" RECOGNITION SITES ARE MOST WIDELY USED. BOTH METHODS ARE APPLIED AS VIRTUALLY EQUIVALENT, DESPITE THE HINTS THAT THEIR RESULTS ONLY PARTLY AGREE. THIS TRIGGERED THE PRESENT AGREEMENT ASSESSMENTS. RESULTS: THREE DIFFERENT HUMAN CELL TYPES (CULTURED MCF7 AND SHSY5Y CELL LINES TREATED WITH DIFFERENT CHEMICAL MODULATORS OF DNA METHYLATION AND WHOLE BLOOD DRAWN FROM PAIN PATIENTS AND HEALTHY VOLUNTEERS) WERE SUBMITTED TO THE GLOBAL DNA METHYLATION ASSAYS EMPLOYING LINE-1 OR LUMA-BASED PYROSEQUENCING MEASUREMENTS. THE AGREEMENT BETWEEN THE TWO BIOASSAYS WAS ASSESSED USING GENERALLY ACCEPTED APPROACHES TO THE STATISTICS FOR LABORATORY METHOD COMPARISON STUDIES. ALTHOUGH GLOBAL DNA METHYLATION LEVELS MEASURED BY THE TWO METHODS CORRELATED, FIVE DIFFERENT LINES OF STATISTICAL EVIDENCE CONSISTENTLY REJECTED THE ASSUMPTION OF COMPLETE AGREEMENT. SPECIFICALLY, A BIAS WAS OBSERVED BETWEEN THE TWO METHODS. IN ADDITION, BOTH THE MAGNITUDE AND DIRECTION OF BIAS WERE TISSUE-DEPENDENT. INTERASSAY DIFFERENCES COULD BE GROUPED BASED ON BAYESIAN STATISTICS, AND THESE GROUPS ALLOWED IN TURN TO RE-IDENTIFY THE ORIGINATING TISSUE. CONCLUSIONS: ALTHOUGH PROVIDING PARTLY CORRELATED MEASUREMENTS OF DNA METHYLATION, INTERCHANGEABILITY OF THE QUANTITATIVE RESULTS OBTAINED WITH LINE-1 AND LUMA WAS JEOPARDIZED BY A CONSISTENT BIAS BETWEEN THE RESULTS. MOREOVER, THE PRESENT ANALYSES STRONGLY INDICATE A TISSUE SPECIFICITY OF THE DIFFERENCES BETWEEN THE TWO METHODS. 2016 12 2074 39 EPIGENETIC DEREGULATION IN CHRONIC LYMPHOCYTIC LEUKEMIA: CLINICAL AND BIOLOGICAL IMPACT. DEREGULATED TRANSCRIPTIONAL CONTROL CAUSED BY ABERRANT DNA METHYLATION AND/OR HISTONE MODIFICATIONS IS A HALLMARK OF CANCER CELLS. IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), THE MOST COMMON ADULT LEUKEMIA, THE EPIGENETIC 'LANDSCAPE' HAS ADDED A NEW LAYER OF COMPLEXITY TO OUR UNDERSTANDING OF THIS CLINICALLY AND BIOLOGICALLY HETEROGENEOUS DISEASE. EARLY STUDIES IDENTIFIED ABERRANT DNA METHYLATION, OFTEN BASED ON SINGLE GENE PROMOTER ANALYSIS WITH BOTH BIOLOGICAL AND CLINICAL IMPACT. SUBSEQUENT GENOME-WIDE PROFILING STUDIES REVEALED DIFFERENTIAL DNA METHYLATION BETWEEN CLLS AND CONTROLS AND IN PROGNOSTICS SUBGROUPS OF THE DISEASE. FROM THESE STUDIES, IT BECAME APPARENT THAT DNA METHYLATION IN REGIONS OUTSIDE OF PROMOTERS, SUCH AS ENHANCERS, IS IMPORTANT FOR THE REGULATION OF CODING GENES AS WELL AS FOR THE REGULATION OF NON-CODING RNAS. ALTHOUGH DNA METHYLATION PROFILES ARE REPORTEDLY STABLE OVER TIME AND IN RELATION TO THERAPY, A HIGHER EPIGENETIC HETEROGENEITY OR 'BURDEN' IS SEEN IN MORE AGGRESSIVE CLL SUBGROUPS, ALBEIT AS NON-RECURRENT 'PASSENGER' EVENTS. MORE RECENTLY, DNA METHYLATION PROFILES IN CLL ANALYZED IN RELATION TO DIFFERENTIATING NORMAL B-CELL POPULATIONS REVEALED THAT THE MAJORITY OF THE CLL EPIGENOME REFLECTS THE EPIGENOMES PRESENT IN THE CELL OF ORIGIN AND THAT ONLY A SMALL FRACTION OF THE EPIGENETIC ALTERATIONS REPRESENTS TRULY CLL-SPECIFIC CHANGES. FURTHERMORE, CLL PATIENTS CAN BE GROUPED INTO AT LEAST THREE CLINICALLY RELEVANT EPIGENETIC SUBGROUPS, POTENTIALLY ORIGINATING FROM DIFFERENT CELLS AT VARIOUS STAGES OF DIFFERENTIATION AND ASSOCIATED WITH DISTINCT OUTCOMES. IN THIS REVIEW, WE SUMMARIZE THE CURRENT UNDERSTANDING OF THE DNA METHYLOME IN CLL, THE ROLE OF HISTONE MODIFYING ENZYMES, HIGHLIGHT INSIGHTS DERIVED FROM ANIMAL MODELS AND ATTEMPTS MADE TO TARGET EPIGENETIC REGULATORS IN CLL ALONG WITH THE FUTURE DIRECTIONS OF THIS RAPIDLY ADVANCING FIELD. 2018 13 3056 36 GENOME-WIDE DNA METHYLATION ANALYSIS IMPLICATES ENRICHMENT OF INTERFERON PATHWAY IN AFRICAN AMERICAN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS AND EUROPEAN AMERICANS WITH LUPUS NEPHRITIS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC, MULTISYSTEM, INFLAMMATORY AUTOIMMUNE DISEASE THAT DISPROPORTIONATELY AFFECTS WOMEN. TRENDS IN SLE PREVALENCE AND CLINICAL COURSE DIFFER BY ANCESTRY, WITH THOSE OF AFRICAN AMERICAN ANCESTRY PRESENTING WITH MORE ACTIVE, SEVERE AND RAPIDLY PROGRESSIVE DISEASE THAN EUROPEAN AMERICANS. PREVIOUS RESEARCH ESTABLISHED ALTERED EPIGENETIC SIGNATURES IN SLE PATIENTS COMPARED TO CONTROLS. HOWEVER, THE CONTRIBUTION OF ABERRANT DNA METHYLATION (DNAM) TO THE RISK OF SLE BY ANCESTRY AND DIFFERENCES AMONG PATIENTS WITH SLE-ASSOCIATED LUPUS NEPHRITIS (LN) HAS NOT BEEN WELL DESCRIBED. WE EVALUATED THE DNA METHYLOMES OF 87 INDIVIDUALS INCLUDING 41 SLE PATIENTS, WITH AND WITHOUT LN, AND 46 CONTROLS ENROLLED IN AN ANCESTRY DIVERSE, WELL-CHARACTERIZED COHORT STUDY OF ESTABLISHED SLE (41 SLE PATIENTS [20 SLE-LN+, 21 SLE-LN-] AND 46 SEX-, RACE- AND AGE-MATCHED CONTROLS; 55% AFRICAN AMERICAN, 45% EUROPEAN AMERICAN). PARTICIPANTS WERE GENOTYPED USING THE INFINIUM GLOBAL DIVERSITY ARRAY (GDA), AND GENETIC ANCESTRY WAS ESTIMATED USING PRINCIPAL COMPONENTS. GENOME-WIDE DNA METHYLATION WAS INITIALLY MEASURED USING THE ILLUMINA METHYLATIONEPIC 850K BEADCHIP ARRAY FOLLOWED BY METHYLATION-SPECIFIC QPCR TO VALIDATE THE METHYLATION STATUS AT PUTATIVE LOCI. DIFFERENTIALLY METHYLATED POSITIONS (DMP) WERE IDENTIFIED USING A CASE-CONTROL APPROACH ADJUSTED FOR ANCESTRY. WE IDENTIFIED A TOTAL OF 51 DMPS IN CPGS AMONG SLE PATIENTS COMPARED TO CONTROLS. GENES PROXIMAL TO THESE CPGS WERE HIGHLY ENRICHED FOR INVOLVEMENT IN TYPE I INTERFERON SIGNALING. DMPS AMONG EUROPEAN AMERICAN SLE PATIENTS WITH LN WERE SIMILAR TO AFRICAN AMERICAN SLE PATIENTS WITH AND WITHOUT LN. OUR FINDINGS WERE VALIDATED USING AN ORTHOGONAL, METHYL-SPECIFIC PCR FOR THREE SLE-ASSOCIATED DMPS NEAR OR PROXIMAL TO MX1, USP18, AND IFITM1. OUR STUDY CONFIRMS PREVIOUS REPORTS THAT DMPS IN CPGS ASSOCIATED WITH SLE ARE ENRICHED IN TYPE I INTERFERON GENES. HOWEVER, WE SHOW THAT EUROPEAN AMERICAN SLE PATIENTS WITH LN HAVE SIMILAR DNAM PATTERNS TO AFRICAN AMERICAN SLE PATIENTS IRRESPECTIVE OF LN, SUGGESTING THAT ABERRANT DNAM ALTERS ACTIVITY OF TYPE I INTERFERON PATHWAY LEADING TO MORE SEVERE DISEASE INDEPENDENT OF ANCESTRY. 2023 14 497 27 ASSOCIATION BETWEEN BMI AND DNA METHYLATION IN BLOOD OR NORMAL ADULT BREAST TISSUE: A SYSTEMATIC REVIEW. BACKGROUND/AIM: SEVERAL STUDIES HAVE INVESTIGATED THE INFLUENCE OF OBESITY ON DNA METHYLATION (DNAM) TO FIND BIOMARKERS ASSOCIATED WITH THE DETECTION OF CHRONIC DISEASES, INCLUDING BREAST CANCER. THE AIM OF THE STUDY WAS TO SYSTEMATICALLY REVIEW STUDIES EXAMINING THE ASSOCIATION OF BODY MASS INDEX (BMI) AND DNAM IN BLOOD OR NORMAL BREAST TISSUE. MATERIALS AND METHODS: THREE SCIENTIFIC LITERATURE DATABASES (PUBMED, EMBASE AND WEB OF SCIENCE) WERE SCREENED UNTIL MAY 2018. RESULTS: TWENTY-FOUR STUDIES WERE INCLUDED ALONG WITH OURS IN WHICH WE INVESTIGATED THIS RELATION IN THE NORMAL BREAST TISSUE OF 40 BREAST CANCER PATIENTS. CONCLUSION: BMI-ASSOCIATED CPG SITES WERE HIGHLY VARIABLE WITH FEW IDENTIFIED IN LESS THAN HALF OF THE STUDIES. NEVERTHELESS, A FEW GENES POTENTIALLY ASSOCIATED WITH BMI WERE HIGHLIGHTED IN BLOOD (CPT1A, ABCG1, SREBF1 AND LGALS3BP) AND IN NORMAL BREAST TISSUE (PTPRN2 AND ABLIM2). THE VARIABILITY OF THE RESULTS COULD BE EXPLAINED BY THE TISSUE AND CELL-SPECIFICITY OF METHYLATION AND DIFFERENCES IN METHODOLOGY. 2020 15 1516 46 DNA METHYLATION AS A BIOMARKER OF AGING IN EPIDEMIOLOGIC STUDIES. CANCER IS LARGELY AN AGING DISEASE. ACCELERATED BIOLOGICAL AGING MAY BE THE STRONGEST PREDICTOR OF CANCER AND OTHER CHRONIC DISEASE RISKS. IN THE ABSENCE OF RELIABLE AND QUANTIFIABLE BIOMARKERS OF AGING TO DATE, IT HAS LONG BEEN OBSERVED THAT TUMORIGENESIS SHARES DISTINCT EPIGENETIC ALTERATIONS WITH THE AGING PROCESS. RECENTLY, EPIGENETIC AGE ESTIMATES HAVE BEEN DEVELOPED BASED ON THE AVAILABILITY OF GENOME-WIDE DNA METHYLATION PROFILES, BY APPLYING IN THE PREDICTION FORMULA THE METHYLATION LEVEL AT A SUBSET OF HIGHLY PREDICTIVE METHYLATION SITES, CALLED EPIGENETIC CLOCK. THESE DNA METHYLATION AGE ESTIMATES HAVE PRODUCED REMARKABLY STRONG CORRELATIONS WITH CHRONOLOGICAL AGE, WITH A SMALL DEVIATION AND HIGH REPRODUCIBILITY ACROSS DIFFERENT AGE GROUPS AND STUDY POPULATIONS. MOREOVER, AN INCREASING NUMBER OF EPIDEMIOLOGIC STUDIES HAVE DEMONSTRATED AN INDEPENDENT ASSOCIATION OF DNA METHYLATION AGE OR THE EXTENT OF ACCELERATION WITH MORTALITY AND VARIOUS AGING-RELATED CONDITIONS, EVEN AFTER ACCOUNTING FOR DIFFERENCES IN CHRONOLOGICAL AGE AND OTHER RISK FACTORS. ALTHOUGH EPIGENETIC PROFILES ARE KNOWN TO BE TISSUE-SPECIFIC, BOTH TARGET TISSUE- AND MULTIPLE TISSUE-DERIVED ESTIMATES APPEAR TO PERFORM WELL TO CAPTURE WHAT IS THOUGHT TO BE THE CUMULATIVE EPIGENETIC DRIFT THAT REPRESENTS A MULTIFACTORIAL DEGENERATIVE PROCESS ACROSS TISSUES AND ORGANISMS. FURTHER REFINEMENT OF THE EPIGENETIC AGE ESTIMATES IS ANTICIPATED OVER TIME TO ACCOMMODATE A BETTER TECHNOLOGICAL COVERAGE OF THE METHYLOME AND A BETTER UNDERSTANDING OF THE BIOLOGY UNDERLYING PREDICTIVE REGIONS. EPIDEMIOLOGIC PRINCIPLES WILL REMAIN CRITICAL FOR THE EVALUATION OF RESEARCH FINDINGS INVOLVING, FOR EXAMPLE, DIFFERENT STUDY POPULATIONS, DESIGN, FOLLOW-UP TIME, AND QUALITY OF COVARIATE DATA. OVERALL, THE EPIGENETIC AGE ESTIMATES ARE AN EXCITING DEVELOPMENT WITH USEFUL IMPLICATIONS FOR BIOMEDICAL RESEARCH OF HEALTHY AGING AND DISEASE PREVENTION AND CONTROL. 2018 16 6112 48 THE EPIGENETIC CLOCK AS A PREDICTOR OF DISEASE AND MORTALITY RISK: A SYSTEMATIC REVIEW AND META-ANALYSIS. BACKGROUND: AGEING IS ONE OF THE PRINCIPAL RISK FACTORS FOR MANY CHRONIC DISEASES. HOWEVER, THERE IS CONSIDERABLE BETWEEN-PERSON VARIATION IN THE RATE OF AGEING AND INDIVIDUAL DIFFERENCES IN THEIR SUSCEPTIBILITY TO DISEASE AND DEATH. EPIGENETIC MECHANISMS MAY PLAY A ROLE IN HUMAN AGEING, AND DNA METHYLATION AGE BIOMARKERS MAY BE GOOD PREDICTORS OF AGE-RELATED DISEASES AND MORTALITY RISK. THE AIMS OF THIS SYSTEMATIC REVIEW WERE TO IDENTIFY AND SYNTHESISE THE EVIDENCE FOR AN ASSOCIATION BETWEEN PERIPHERALLY MEASURED DNA METHYLATION AGE AND LONGEVITY, AGE-RELATED DISEASE, AND MORTALITY RISK. METHODS: A SYSTEMATIC SEARCH WAS CONDUCTED IN LINE WITH THE PREFERRED REPORTING ITEMS FOR SYSTEMATIC REVIEWS AND META-ANALYSES (PRISMA) GUIDELINES. USING RELEVANT SEARCH TERMS, MEDLINE, EMBASE, COCHRANE CENTRAL REGISTER OF CONTROLLED TRIALS, AND PSYCHINFO DATABASES WERE SEARCHED TO IDENTIFY ARTICLES MEETING THE INCLUSION CRITERIA. STUDIES WERE ASSESSED FOR BIAS USING JOANNA BRIGGS INSTITUTE CRITICAL APPRAISAL CHECKLISTS. DATA WAS EXTRACTED FROM STUDIES MEASURING AGE ACCELERATION AS A PREDICTOR OF AGE-RELATED DISEASES, MORTALITY OR LONGEVITY, AND THE FINDINGS FOR SIMILAR OUTCOMES COMPARED. USING REVIEW MANAGER 5.3 SOFTWARE, TWO META-ANALYSES (ONE PER EPIGENETIC CLOCK) WERE CONDUCTED ON STUDIES MEASURING ALL-CAUSE MORTALITY. RESULTS: TWENTY-THREE RELEVANT ARTICLES WERE IDENTIFIED, INCLUDING A TOTAL OF 41,607 PARTICIPANTS. FOUR STUDIES FOCUSED ON AGEING AND LONGEVITY, 11 ON AGE-RELATED DISEASE (CANCER, CARDIOVASCULAR DISEASE, AND DEMENTIA), AND 11 ON MORTALITY. THERE WAS SOME, ALTHOUGH INCONSISTENT, EVIDENCE FOR AN ASSOCIATION BETWEEN INCREASED DNA METHYLATION AGE AND RISK OF DISEASE. META-ANALYSES INDICATED THAT EACH 5-YEAR INCREASE IN DNA METHYLATION AGE WAS ASSOCIATED AN 8 TO 15% INCREASED RISK OF MORTALITY. CONCLUSION: DUE TO THE SMALL NUMBER OF STUDIES AND HETEROGENEITY IN STUDY DESIGN AND OUTCOMES, THE ASSOCIATION BETWEEN DNA METHYLATION AGE AND AGE-RELATED DISEASE AND LONGEVITY IS INCONCLUSIVE. INCREASED EPIGENETIC AGE WAS ASSOCIATED WITH MORTALITY RISK, BUT POSITIVE PUBLICATION BIAS NEEDS TO BE CONSIDERED. FURTHER RESEARCH IS NEEDED TO DETERMINE THE EXTENT TO WHICH DNA METHYLATION AGE CAN BE USED AS A CLINICAL BIOMARKER. 2019 17 414 32 ANALYSIS OF PROMOTER METHYLATION IN STOOL: A NOVEL METHOD FOR THE DETECTION OF COLORECTAL CANCER. BACKGROUND & AIMS: DETECTION OF TUMOR-DERIVED DNA ALTERATIONS IN STOOL IS AN INTRIGUING NEW APPROACH WITH HIGH POTENTIAL FOR THE NONINVASIVE DETECTION OF COLORECTAL CANCER (CRC). BECAUSE OF HETEROGENEITY OF TUMORS, USUALLY MULTIPLE MARKERS DISTRIBUTED THROUGHOUT THE HUMAN GENOME NEED TO BE ANALYZED. THIS IS LABOR INTENSIVE AND DOES NOT ALLOW FOR HIGH THROUGH-PUT SCREENING. THEREFORE, MARKERS WITH HIGH SENSITIVITY AND GOOD SPECIFICITY ARE NEEDED. WE EXPLORED THE POTENTIAL OF A SINGLE EPIGENETIC MARKER IN COMPARISON WITH FECAL OCCULT BLOOD TESTING (FOBT) FOR THE DISCRIMINATION OF PATIENTS WITH CRCS AND ADENOMAS FROM THOSE WITHOUT. METHODS: METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) WAS PERFORMED TO ANALYZE HYPERMETHYLATED IN CANCER 1 (HIC1) PROMOTER METHYLATION STATUS IN A BLINDED FASHION IN STOOL SAMPLES FROM 26 PATIENTS WITH CRC, 13 WITH ADENOMA > OR =1 CM, 9 WITH HYPERPLASTIC POLYPS, 9 WITH CHRONIC INFLAMMATORY BOWEL DISEASE, AND 32 WITH ENDOSCOPICALLY NORMAL COLON. RESULTS: NINETY-SEVEN PERCENT OF THE STOOL SAMPLES CONTAINED AMPLIFIABLE DNA. FORTY-TWO PERCENT OF THE SAMPLES FROM PATIENTS WITH CRC AND 31% OF THE SAMPLES FROM PATIENTS WITH COLORECTAL ADENOMA > OR =1 CM WERE POSITIVE FOR HIC1 PROMOTER METHYLATION. NO METHYLATED HIC1 PROMOTER DNA WAS DETECTED IN THE FECAL DNA FROM PATIENTS WITH ENDOSCOPICALLY NORMAL COLON OR HYPERPLASTIC POLYPS. CONCLUSIONS: THE EPIGENETIC MARKER HIC1 PROMOTER METHYLATION CARRIES HIGH POTENTIAL FOR THE REMOTE DETECTION OF CRCS. WE POSTULATE THAT A PANEL OF MERELY A FEW GENETIC AND EPIGENETIC MARKERS WILL BE REQUIRED FOR THE HIGHLY SENSITIVE AND SPECIFIC DETECTION OF CRCS AND ADENOMAS IN FECAL SAMPLES FROM AFFECTED PATIENTS. 2005 18 2418 34 EPIGENETIC SIGNATURE OF CHRONIC LOW BACK PAIN IN HUMAN T CELLS. OBJECTIVE: DETERMINE IF CHRONIC LOW BACK PAIN (LBP) IS ASSOCIATED WITH DNA METHYLATION SIGNATURES IN HUMAN T CELLS THAT WILL REVEAL NOVEL MECHANISMS AND POTENTIAL THERAPEUTIC TARGETS AND EXPLORE THE FEASIBILITY OF EPIGENETIC DIAGNOSTIC MARKERS FOR PAIN-RELATED PATHOPHYSIOLOGY. METHODS: GENOME-WIDE DNA METHYLATION ANALYSIS OF 850,000 CPG SITES IN WOMEN AND MEN WITH CHRONIC LBP AND PAIN-FREE CONTROLS WAS PERFORMED. T CELLS WERE ISOLATED (DISCOVERY COHORT, N = 32) AND USED TO IDENTIFY DIFFERENTIALLY METHYLATED CPG SITES, AND GENE ONTOLOGIES AND MOLECULAR PATHWAYS WERE IDENTIFIED. A POLYGENIC DNA METHYLATION SCORE FOR LBP WAS GENERATED IN BOTH WOMEN AND MEN. VALIDATION WAS PERFORMED IN AN INDEPENDENT COHORT (VALIDATION COHORT, N = 63) OF CHRONIC LBP AND HEALTHY CONTROLS. RESULTS: ANALYSIS WITH THE DISCOVERY COHORT REVEALED A TOTAL OF 2,496 AND 419 DIFFERENTIALLY METHYLATED CPGS IN WOMEN AND MEN, RESPECTIVELY. IN WOMEN, MOST OF THESE SITES WERE HYPOMETHYLATED AND ENRICHED IN GENES WITH FUNCTIONS IN THE EXTRACELLULAR MATRIX, IN THE IMMUNE SYSTEM (IE, CYTOKINES), OR IN EPIGENETIC PROCESSES. IN MEN, A UNIQUE CHRONIC LBP DNA METHYLATION SIGNATURE WAS IDENTIFIED CHARACTERIZED BY SIGNIFICANT ENRICHMENT FOR GENES FROM THE MAJOR HISTOCOMPATIBILITY COMPLEX. SEX-SPECIFIC POLYGENIC DNA METHYLATION SCORES WERE GENERATED TO ESTIMATE THE PAIN STATUS OF EACH INDIVIDUAL AND CONFIRMED IN THE VALIDATION COHORT USING PYROSEQUENCING. CONCLUSION: THIS STUDY REVEALS SEX-SPECIFIC DNA METHYLATION SIGNATURES IN HUMAN T CELLS THAT DISCRIMINATES CHRONIC LBP PARTICIPANTS FROM HEALTHY CONTROLS. 2021 19 1585 33 DNA METHYLATION PROFILING IDENTIFIES EPIGENETIC DIFFERENCES BETWEEN DIABETES PATIENTS WITH ESRD AND DIABETES PATIENTS WITHOUT NEPHROPATHY. WE IDENTIFIED POTENTIAL EPIGENETIC BIOMARKERS FOR CHRONIC KIDNEY DISEASE PROGRESSION BY COMPARING SITE-SPECIFIC DNA METHYLATION LEVELS IN MORE THAN 14,000 GENES BETWEEN AFRICAN AMERICAN AND HISPANIC DIABETES PATIENTS WITH END STAGE RENAL DISEASE (ESRD) AND DIABETES PATIENTS WITHOUT NEPHROPATHY. WE IDENTIFIED 187 GENES THAT ARE DIFFERENTIALLY METHYLATED BETWEEN THE TWO GROUPS ON AT LEAST TWO CPG SITES IN EACH GENE IN DNA EXTRACTED FROM SALIVA. OF THE 187 GENES WHOSE MEAN METHYLATION LEVELS DIFFERED BETWEEN THE TWO GROUPS, 39 GENES, OR CLOSELY RELATED GENE FAMILY MEMBERS, HAVE BEEN REPORTED TO BE INVOLVED IN KIDNEY DEVELOPMENT OR DIABETIC NEPHROPATHY, PER SE, OR HAVE BEEN ASSOCIATED WITH DIALYSIS-INDUCED CHANGES IN GENE EXPRESSION IN PERIPHERAL BLOOD CELLS. THE FACT THAT SUCH A SUBSTANTIAL FRACTION (21%) OF THE 187 CANDIDATE GENES HAVE BEEN IMPLICATED PREVIOUSLY THROUGH GENOME ASSOCIATION OR TRANSCRIPTION PROFILING STUDIES SUGGESTS STRONGLY THAT THE DNA METHYLATION DIFFERENCES WE OBSERVE ARE ASSOCIATED WITH DISEASE PREDISPOSITION AND/OR TREATMENT. THE FACT THAT THESE NEPHROPATHY AND/OR DIALYSIS-ASSOCIATED DIFFERENCES BETWEEN PATIENTS WERE IDENTIFIED IN DNA EXTRACTED FROM SALIVA OFFERS PROOF-OF-PRINCIPLE THAT INTER-INDIVIDUAL EPIGENETIC DIFFERENCES MAY PROVE USEFUL AS PREDICTIVE BIOMARKERS OF DISEASE SUSCEPTIBILITY. 2011 20 1705 38 DYNAMICS OF SMOKING-INDUCED GENOME-WIDE METHYLATION CHANGES WITH TIME SINCE SMOKING CESSATION. SEVERAL STUDIES HAVE RECENTLY IDENTIFIED STRONG EPIGENETIC SIGNALS RELATED TO TOBACCO SMOKING. HOWEVER, AN ASPECT THAT DID NOT RECEIVE MUCH ATTENTION IS THE EVOLUTION OF EPIGENETIC CHANGES WITH TIME SINCE SMOKING CESSATION. WE CONDUCTED A SERIES OF EPIGENOME-WIDE ASSOCIATION STUDIES TO CAPTURE THE DYNAMICS OF SMOKING-INDUCED EPIGENETIC CHANGES AFTER SMOKING CESSATION, USING GENOME-WIDE METHYLATION PROFILES OBTAINED FROM BLOOD SAMPLES IN 745 WOMEN FROM 2 EUROPEAN POPULATIONS. TWO DISTINCT CLASSES OF CPG SITES WERE IDENTIFIED: SITES WHOSE METHYLATION REVERTS TO LEVELS TYPICAL OF NEVER SMOKERS WITHIN DECADES AFTER SMOKING CESSATION, AND SITES REMAINING DIFFERENTIALLY METHYLATED, EVEN MORE THAN 35 YEARS AFTER SMOKING CESSATION. OUR RESULTS SUGGEST THAT THE DYNAMICS OF METHYLATION CHANGES FOLLOWING SMOKING CESSATION ARE DRIVEN BY A DIFFERENTIAL AND SITE-SPECIFIC MAGNITUDE OF THE SMOKING-INDUCED ALTERATIONS (WITH PERSISTENT SITES BEING MOST AFFECTED) IRRESPECTIVE OF THE INTENSITY AND DURATION OF SMOKING. ANALYSES OF THE LINK BETWEEN METHYLATION AND EXPRESSION LEVELS REVEALED THAT METHYLATION PREDOMINANTLY AND REMOTELY DOWN-REGULATES GENE EXPRESSION. AMONG GENES WHOSE EXPRESSION WAS ASSOCIATED WITH OUR CANDIDATE CPG SITES, LRRN3 APPEARED TO BE PARTICULARLY INTERESTING AS IT WAS ONE OF THE FEW GENES WHOSE METHYLATION AND EXPRESSION WERE DIRECTLY ASSOCIATED, AND THE ONLY GENE IN WHICH BOTH METHYLATION AND GENE EXPRESSION WERE FOUND ASSOCIATED WITH SMOKING. OUR STUDY HIGHLIGHTS PERSISTENT EPIGENETIC MARKERS OF SMOKING, WHICH CAN POTENTIALLY BE DETECTED DECADES AFTER CESSATION. SUCH HISTORICAL SIGNATURES ARE PROMISING BIOMARKERS TO REFINE INDIVIDUAL RISK PROFILING OF SMOKING-INDUCED CHRONIC DISEASE SUCH AS LUNG CANCER. 2015