1 468 136 ARGININE METHYLTRANSFERASES MEDIATE AN EPIGENETIC OVARIAN RESPONSE TO ENDOMETRIOSIS. ENDOMETRIOSIS IS ASSOCIATED WITH INFERTILITY AND DEBILITATING CHRONIC PAIN. ABNORMAL EPIGENETIC MODIFICATIONS IN THE HUMAN ENDOMETRIUM HAVE RECENTLY BEEN IMPLICATED IN THE PATHOGENESIS OF THIS CONDITION. HOWEVER, WHETHER AN ALTERED EPIGENETIC LANDSCAPE CONTRIBUTES TO PATHOLOGICAL CHANGES IN THE OVARY IS UNKNOWN. USING AN ESTABLISHED BABOON ENDOMETRIOSIS MODEL, EARLY-, AND LATE-STAGE EPIGENETIC CHANGES IN THE OVARY WERE INVESTIGATED. TRANSCRIPT PROFILING OF KEY CHROMATIN-MODIFYING ENZYMES USING PATHWAY-FOCUSED PCR ARRAYS ON OVARIAN TISSUE FROM HEALTHY CONTROL ANIMALS AND AT 3 AND 15 MONTHS OF ENDOMETRIOSIS REVEALED DRAMATIC CHANGES IN GENE EXPRESSION IN A DISEASE DURATION-DEPENDENT MANNER. INGENUITY PATHWAY ANALYSIS INDICATED THAT TRANSCRIPTS FOR CHROMATIN-REMODELING ENZYMES ASSOCIATED WITH REPRODUCTIVE SYSTEM DISEASE AND CANCER DEVELOPMENT WERE ABNORMALLY REGULATED, MOST PROMINENTLY THE ARGININE METHYLTRANSFERASES CARM1, PRMT2, AND PRMT8. DOWNREGULATION OF CARM1 PROTEIN EXPRESSION WAS ALSO DETECTED IN THE OVARY, FULLY-GROWN OOCYTES AND EUTOPIC ENDOMETRIUM FOLLOWING 15 MONTHS OF ENDOMETRIOSIS. SODIUM BISULFITE SEQUENCING REVEALED DNA HYPERMETHYLATION WITHIN THE PRMT8 PROMOTER, SUGGESTING THAT DEREGULATED CPG METHYLATION MAY PLAY A ROLE IN TRANSCRIPTIONAL REPRESSION OF THIS GENE. THESE RESULTS DEMONSTRATE THAT ENDOMETRIOSIS IS ASSOCIATED WITH CHANGES OF EPIGENETIC PROFILES IN THE PRIMATE OVARY AND SUGGEST THAT ARGININE METHYLTRANSFERASES PLAY A PROMINENT ROLE IN MEDIATING THE OVARIAN RESPONSE TO ENDOMETRIOSIS. OWING TO THE CRITICAL ROLE OF CARM1 IN NUCLEAR RECEPTOR-MEDIATED TRANSCRIPTION AND MAINTENANCE OF PLURIPOTENCY IN THE CLEAVAGE STAGE EMBRYO, OUR RESULTS SUGGEST THAT EPIGENETIC ALTERATIONS IN THE OVARY MAY HAVE FUNCTIONAL CONSEQUENCES FOR OOCYTE QUALITY AND THE ETIOLOGY OF INFERTILITY ASSOCIATED WITH ENDOMETRIOSIS. 2015 2 3061 50 GENOME-WIDE DNA METHYLATION ANALYSIS PREDICTS AN EPIGENETIC SWITCH FOR GATA FACTOR EXPRESSION IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A GYNECOLOGICAL DISEASE DEFINED BY THE EXTRAUTERINE GROWTH OF ENDOMETRIAL-LIKE CELLS THAT CAUSE CHRONIC PAIN AND INFERTILITY. THE DISEASE IS LIMITED TO PRIMATES THAT EXHIBIT SPONTANEOUS DECIDUALIZATION, AND DISEASED CELLS ARE CHARACTERIZED BY SIGNIFICANT DEFECTS IN THE STEROID-DEPENDENT GENETIC PATHWAYS THAT TYPIFY THIS PROCESS. ALTERED DNA METHYLATION MAY UNDERLIE THESE DEFECTS, BUT FEW REGIONS WITH DIFFERENTIAL METHYLATION HAVE BEEN IMPLICATED IN THE DISEASE. WE MAPPED GENOME-WIDE DIFFERENCES IN DNA METHYLATION BETWEEN HEALTHY HUMAN ENDOMETRIAL AND ENDOMETRIOTIC STROMAL CELLS AND CORRELATED THIS WITH GENE EXPRESSION USING AN INTERACTION ANALYSIS STRATEGY. WE IDENTIFIED 42,248 DIFFERENTIALLY METHYLATED CPGS IN ENDOMETRIOSIS COMPARED TO HEALTHY CELLS. THESE EXTENSIVE DIFFERENCES WERE NOT UNIDIRECTIONAL, BUT WERE FOCUSED INTRAGENICALLY AND AT SITES DISTAL TO CLASSIC CPG ISLANDS WHERE METHYLATION STATUS WAS TYPICALLY NEGATIVELY CORRELATED WITH GENE EXPRESSION. SIGNIFICANT DIFFERENCES IN METHYLATION WERE MAPPED TO 403 GENES, WHICH INCLUDED A DISPROPORTIONALLY LARGE NUMBER OF TRANSCRIPTION FACTORS. FURTHERMORE, MANY OF THESE GENES ARE IMPLICATED IN THE PATHOLOGY OF ENDOMETRIOSIS AND DECIDUALIZATION. OUR RESULTS TREMENDOUSLY IMPROVE THE SCOPE AND RESOLUTION OF DIFFERENTIAL METHYLATION AFFECTING THE HOX GENE CLUSTERS, NUCLEAR RECEPTOR GENES, AND INTRIGUINGLY THE GATA FAMILY OF TRANSCRIPTION FACTORS. FUNCTIONAL ANALYSIS OF THE GATA FAMILY REVEALED THAT GATA2 REGULATES KEY GENES NECESSARY FOR THE HORMONE-DRIVEN DIFFERENTIATION OF HEALTHY STROMAL CELLS, BUT IS HYPERMETHYLATED AND REPRESSED IN ENDOMETRIOTIC CELLS. GATA6, WHICH IS HYPOMETHYLATED AND ABUNDANT IN ENDOMETRIOTIC CELLS, POTENTLY BLOCKED HORMONE SENSITIVITY, REPRESSED GATA2, AND INDUCED MARKERS OF ENDOMETRIOSIS WHEN EXPRESSED IN HEALTHY ENDOMETRIAL CELLS. THE UNIQUE EPIGENETIC FINGERPRINT IN ENDOMETRIOSIS SUGGESTS DNA METHYLATION IS AN INTEGRAL COMPONENT OF THE DISEASE, AND IDENTIFIES A NOVEL ROLE FOR THE GATA FAMILY AS KEY REGULATORS OF UTERINE PHYSIOLOGY-ABERRANT DNA METHYLATION IN ENDOMETRIOTIC CELLS CORRELATES WITH A SHIFT IN GATA ISOFORM EXPRESSION THAT FACILITATES PROGESTERONE RESISTANCE AND DISEASE PROGRESSION. 2014 3 146 42 ABERRANT ENDOMETRIAL DNA METHYLOME AND ASSOCIATED GENE EXPRESSION IN WOMEN WITH ENDOMETRIOSIS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT, PROGESTERONE-RESISTANT DISORDER LARGELY DERIVED FROM RETROGRADE TRANSPLANTATION OF MENSTRUAL TISSUE/CELLS INTO THE PELVIS, ELICITING AN INFLAMMATORY RESPONSE, PELVIC PAIN, AND INFERTILITY. EUTOPIC ENDOMETRIUM (WITHIN THE UTERUS), GIVING RISE TO PELVIC DISEASE, DISPLAYS CYCLE-DEPENDENT TRANSCRIPTOMIC, PROTEOMIC, AND SIGNALING ABNORMALITIES, AND ALTHOUGH ITS DNA METHYLATION PROFILES DYNAMICALLY CHANGE ACROSS THE CYCLE IN HEALTHY WOMEN, STUDIES IN ENDOMETRIOSIS ARE LIMITED. HEREIN, WE INVESTIGATED THE DNA METHYLOME AND ASSOCIATED GENE EXPRESSION IN THREE PHASES OF THE CYCLE IN EUTOPIC ENDOMETRIUM OF WOMEN WITH SEVERE ENDOMETRIOSIS VERSUS CONTROLS, MATCHED FOR ETHNICITY, MEDICATIONS, SMOKING, AND NO RECENT CONTRACEPTIVE STEROID USE. GENOME-WIDE DNA METHYLATION AND GENE EXPRESSION WERE COASSESSED IN EACH SAMPLE. CYCLE PHASE WAS DETERMINED BY HISTOLOGY, SERUM HORMONE LEVELS, AND UNSUPERVISED PRINCIPAL COMPONENT AND HIERARCHICAL CLUSTER ANALYSES OF MICROARRAY DATA. ALTERED ENDOMETRIAL DNA METHYLATION IN ENDOMETRIOSIS WAS MOST PROMINENT IN THE MIDSECRETORY PHASE (PEAK PROGESTERONE), WITH DISRUPTION OF THE NORMAL PATTERN OF CYCLE-DEPENDENT DNA METHYLATION CHANGES, INCLUDING A BIAS TOWARD METHYLATION OF CPG ISLANDS, SUGGESTING WIDE-RANGE ABNORMALITIES OF THE CHROMATIN REMODELING MACHINERY IN ENDOMETRIOSIS. DNA METHYLATION CHANGES WERE ASSOCIATED WITH ALTERED GENE EXPRESSION RELEVANT TO ENDOMETRIAL FUNCTION/DYSFUNCTION, INCLUDING CELL PROLIFERATION, INFLAMMATION/IMMUNE RESPONSE, ANGIOGENESIS, AND STEROID HORMONE RESPONSE. THE DATA PROVIDE INSIGHT INTO EPIGENETIC REPROGRAMMING AND STEROID HORMONE ACTIONS IN ENDOMETRIUM CONTRIBUTING TO THE PATHOGENESIS AND PATHOPHYSIOLOGY OF ENDOMETRIOSIS. 2016 4 2297 29 EPIGENETIC REGULATION OF ACUTE INFLAMMATORY PAIN. ACUTE PAIN IS ASSOCIATED WITH TISSUE DAMAGE, WHICH RESULTS IN THE RELEASE OF INFLAMMATORY MEDIATORS. RECENT STUDIES POINT TO THE INVOLVEMENT OF EPIGENETIC MECHANISMS (DNA METHYLATION) IN THE DEVELOPMENT OF PAIN. WE HAVE FOUND THAT DURING ACUTE INFLAMMATORY PAIN INDUCED BY THE APPLICATION OF 10% MUSTARD OIL ON THE TONGUES OF RATS, LEVELS OF DNMT3A AND 3B WERE ELEVATED MARKEDLY (36 AND 42 % RESPECTIVELY), WHEREAS THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY. PREVIOUS INJECTION OF XEFOCAM WITH 0,4 MG/KG DOSE DECREASED LEVELS OF DNMT3A AND 3B (25 AND 24% RESPECTIVELY). THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY COMPARED TO THE CONTROL GROUP. THE FINDINGS SUPPORT THE IDEA THAT INHIBITORS OF DNA-METHYLTRANSFERASES COULD BE USEFUL FOR PAIN MANAGEMENT. OUR DATA SUGGEST THAT NSAIDS (ALONE OR IN COMBINATION WITH DNMT INHIBITORS) MAY BE PROPOSED AS POSSIBLE EPIGENETIC REGULATORY AGENTS, WHICH MAY PLAY A ROLE IN EPIGENETIC MECHANISMS INDIRECTLY THROUGH ALTERING THE ACTIVITY OF INFLAMMATORY MEDIATORS INVOLVED IN PAIN DEVELOPMENT. 2014 5 2926 35 GENERATION OF AN EPIGENETIC SIGNATURE BY CHRONIC HYPOXIA IN PROSTATE CELLS. INCREASING LEVELS OF TISSUE HYPOXIA HAVE BEEN REPORTED AS A NATURAL FEATURE OF THE AGING PROSTATE GLAND AND MAY BE A RISK FACTOR FOR THE DEVELOPMENT OF PROSTATE CANCER. IN THIS STUDY, WE HAVE USED PWR-1E BENIGN PROSTATE EPITHELIAL CELLS AND AN EQUIVALENTLY AGED HYPOXIA-ADAPTED PWR-1E SUB-LINE TO IDENTIFY PHENOTYPIC AND EPIGENETIC CONSEQUENCES OF CHRONIC HYPOXIA IN PROSTATE CELLS. WE HAVE IDENTIFIED A SIGNIFICANTLY ALTERED CELLULAR PHENOTYPE IN RESPONSE TO CHRONIC HYPOXIA AS CHARACTERIZED BY INCREASED RECEPTOR-MEDIATED APOPTOTIC RESISTANCE, THE INDUCTION OF CELLULAR SENESCENCE, INCREASED INVASION AND THE INCREASED SECRETION OF IL-1 BETA, IL6, IL8 AND TNFALPHA CYTOKINES. IN ASSOCIATION WITH THESE PHENOTYPIC CHANGES AND THE ABSENCE OF HIF-1 ALPHA PROTEIN EXPRESSION, WE HAVE DEMONSTRATED SIGNIFICANT INCREASES IN GLOBAL LEVELS OF DNA METHYLATION AND H3K9 HISTONE ACETYLATION IN THESE CELLS, CONCOMITANT WITH THE INCREASED EXPRESSION OF DNA METHYLTRANSFERASE DMNT3B AND GENE-SPECIFIC CHANGES IN DNA METHYLATION AT KEY IMPRINTING LOCI. IN CONCLUSION, WE HAVE DEMONSTRATED A GENOME-WIDE ADJUSTMENT OF DNA METHYLATION AND HISTONE ACETYLATION UNDER CHRONIC HYPOXIC CONDITIONS IN THE PROSTATE. THESE EPIGENETIC SIGNATURES MAY REPRESENT AN ADDITIONAL MECHANISM TO PROMOTE AND MAINTAIN A HYPOXIC-ADAPTED CELLULAR PHENOTYPE WITH A POTENTIAL ROLE IN TUMOUR DEVELOPMENT. 2009 6 1117 33 COMPARATIVE AND EXPERIMENTAL STUDIES ON THE GENES ALTERED BY CHRONIC HYPOXIA IN HUMAN BRAIN MICROENDOTHELIAL CELLS. BACKGROUND : HYPOXIA INDUCIBLE FACTOR 1 ALPHA (HIF1A) IS A MASTER REGULATOR OF ACUTE HYPOXIA; HOWEVER, WITH CHRONIC HYPOXIA, HIF1A LEVELS RETURN TO THE NORMOXIC LEVELS. IMPORTANTLY, THE GENES THAT ARE INVOLVED IN THE CELL SURVIVAL AND VIABILITY UNDER CHRONIC HYPOXIA ARE NOT KNOWN. THEREFORE, WE TESTED THE HYPOTHESIS THAT CHRONIC HYPOXIA LEADS TO THE UPREGULATION OF A CORE GROUP OF GENES WITH ASSOCIATED CHANGES IN THE PROMOTER DNA METHYLATION THAT MEDIATES THE CELL SURVIVAL UNDER HYPOXIA. RESULTS : WE EXAMINED THE EFFECT OF CHRONIC HYPOXIA (3 DAYS; 0.5% OXYGEN) ON HUMAN BRAIN MICRO ENDOTHELIAL CELLS (HBMEC) VIABILITY AND APOPTOSIS. HYPOXIA CAUSED A SIGNIFICANT REDUCTION IN CELL VIABILITY AND AN INCREASE IN APOPTOSIS. NEXT, WE EXAMINED CHRONIC HYPOXIA ASSOCIATED CHANGES IN TRANSCRIPTOME AND GENOME-WIDE PROMOTER METHYLATION. THE DATA OBTAINED WAS COMPARED WITH 16 OTHER MICROARRAY STUDIES ON CHRONIC HYPOXIA. NINE GENES WERE ALTERED IN RESPONSE TO CHRONIC HYPOXIA IN ALL 17 STUDIES. INTERESTINGLY, HIF1A WAS NOT ALTERED WITH CHRONIC HYPOXIA IN ANY OF THE STUDIES. FURTHERMORE, WE COMPARED OUR DATA TO THREE OTHER STUDIES THAT IDENTIFIED HIF-RESPONSIVE GENES BY VARIOUS APPROACHES. ONLY TWO GENES WERE FOUND TO BE HIF DEPENDENT. WE SILENCED EACH OF THESE 9 GENES USING CRISPR/CAS9 SYSTEM. DOWNREGULATION OF EGLN3 SIGNIFICANTLY INCREASED THE CELL DEATH UNDER CHRONIC HYPOXIA, WHEREAS DOWNREGULATION OF ERO1L, ENO2, ADRENOMEDULLIN, AND SPAG4 REDUCED THE CELL DEATH UNDER HYPOXIA. CONCLUSIONS : WE PROVIDE A CORE GROUP OF GENES THAT REGULATES CELLULAR ACCLIMATIZATION UNDER CHRONIC HYPOXIC STRESS, AND MOST OF THEM ARE HIF INDEPENDENT. 2017 7 1567 34 DNA METHYLATION OF THE KLF14 GENE REGION IN WHOLE BLOOD CELLS PROVIDES PREDICTION FOR THE CHRONIC INFLAMMATION IN THE ADIPOSE TISSUE. KRUPPEL-LIKE FACTOR 14 (KLF14) GENE, WHICH APPEARS TO BE A MASTER REGULATOR OF GENE EXPRESSION IN THE ADIPOSE TISSUE AND HAVE PREVIOUSLY BEEN ASSOCIATED WITH BMI AND TYPE 2 DIABETES (T2D) BY LARGE GENOME-WIDE ASSOCIATION STUDIES. IN ORDER TO FIND PREDICTIVE BIOMARKERS FOR THE DEVELOPMENT OF T2D, IT IS NECESSARY TO TAKE EPIGENOMIC CHANGES AFFECTED BY ENVIRONMENTAL FACTORS INTO ACCOUNT. THIS STUDY FOCUSES ON AGEING AND OBESITY, WHICH ARE T2D RISK FACTORS, AND EXAMINES EPIGENETIC CHANGES AND INFLAMMATORY CHANGES. WE INVESTIGATED DNA METHYLATION CHANGES IN THE KLF14 PROMOTER REGION IN DIFFERENT ORGANS OF MICE FOR COMPARING AGING AND WEIGHT. WE FOUND THAT METHYLATION LEVELS OF THESE SITES WERE INCREASED WITH AGING AND WEIGHT IN THE SPLEEN, THE ADIPOSE TISSUE, THE KIDNEY, THE LUNG, THE COLON AND THE WHOLE BLOOD CELLS. IN ADDITION, IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD, THESE EPIGENETIC CHANGES WERE ALSO SIGNIFICANTLY ASSOCIATED WITH INFLAMMATORY LEVELS. MOREOVER, NOT ONLY KLF14, BUT ALSO EXPRESSION LEVELS OF SOME DOWNSTREAM GENES WERE DECREASED WITH METHYLATION IN THE SPLEEN, THE ADIPOSE TISSUE AND THE WHOLE BLOOD CELLS. TAKEN TOGETHER, OUR RESULTS SUGGEST THAT METHYLATION CHANGES OF KLF14 IN THOSE TISSUES MAY BE ASSOCIATED WITH CHANGES IN GENE EXPRESSION AND INFLAMMATION ON THE ADIPOSE TISSUE OF OBESITY AND T2D. IN ADDITION, THE METHYLATION CHANGES IN THE WHOLE BLOOD CELLS MAY SERVE AS A PREDICTIVE EPIGENETIC BIOMARKER FOR THE DEVELOPMENT OF T2D. 2018 8 416 32 ANALYSIS OF THE DYNAMIC ABERRANT LANDSCAPE OF DNA METHYLATION AND GENE EXPRESSION DURING ARSENIC-INDUCED CELL TRANSFORMATION. INORGANIC ARSENIC IS A WELL-KNOWN CARCINOGEN ASSOCIATED WITH SEVERAL TYPES OF CANCER, BUT THE MECHANISMS INVOLVED IN ARSENIC-INDUCED CARCINOGENESIS ARE NOT FULLY UNDERSTOOD. RECENT EVIDENCE POINTS TO EPIGENETIC DYSREGULATION AS AN IMPORTANT MECHANISM IN THIS PROCESS; HOWEVER, THE EFFECTS OF EPIGENETIC ALTERATIONS IN GENE EXPRESSION HAVE NOT BEEN EXPLORED IN DEPTH. USING MICROARRAY DATA AND APPLYING A MULTIVARIATE CLUSTERING ANALYSIS IN A GAUSSIAN MIXTURE MODEL, WE DESCRIBE THE ALTERATIONS IN DNA METHYLATION AROUND THE PROMOTER REGION AND THE IMPACT ON GENE EXPRESSION IN HACAT CELLS DURING THE TRANSFORMATION PROCESS CAUSED BY CHRONIC EXPOSURE TO ARSENIC. USING THIS CLUSTERING APPROACH, THE GENES WERE GROUPED ACCORDING TO THEIR METHYLATION AND EXPRESSION STATUS IN THE EPIGENETIC LANDSCAPE, AND THE CHANGES THAT OCCURRED DURING THE CELLULAR TRANSFORMATION WERE IDENTIFIED ADEQUATELY. THUS, WE PRESENT A VALUABLE METHOD FOR IDENTIFYING EPIGENOMIC DYSREGULATION. 2019 9 5754 23 SOCIAL PSYCHOGENIC STRESS PROMOTES THE DEVELOPMENT OF ENDOMETRIOSIS IN MOUSE. EXPOSURE TO CHRONIC STRESS BEFORE AND WELL AFTER THE INDUCTION OF ENDOMETRIOSIS IS REPORTED TO INCREASE LESION SIZES IN RATS, BUT IT IS UNCLEAR WHETHER STRESS, EXPOSED SHORTLY AFTER THE INDUCTION OF ENDOMETRIOSIS, WOULD ALSO PROMOTE THE DEVELOPMENT OF ENDOMETRIOSIS, NOR IS IT CLEAR WHAT THE UNDERLYING POSSIBLE MOLECULAR MECHANISM IS. THIS STUDY WAS UNDERTAKEN TO TEST THE HYPOTHESIS THAT CHRONIC STRESS CAN PROMOTE THE DEVELOPMENT OF ENDOMETRIOSIS. A PROSPECTIVE RANDOMIZED MOUSE EXPERIMENT WAS CONDUCTED THAT SUBJECTED MICE WITH INDUCED ENDOMETRIOSIS TO PREDATOR STRESS. IN ADDITION, A CROSS-SECTIONAL IMMUNOHISTOCHEMISTRY STUDY WAS PERFORMED IN ECTOPIC AND EUTOPIC ENDOMETRIAL TISSUE SAMPLES FROM AGE- AND ROUGHLY MENSTRUAL PHASE-MATCHED WOMEN WITH OVARIAN ENDOMETRIOMAS. IT WAS FOUND THAT THE CHRONIC PSYCHOGENIC STRESS INDUCED EPIGENETIC CHANGES IN THE HIPPOCAMPUS IN MOUSE INDEPENDENT OF ENDOMETRIOSIS. IT WAS ALSO FOUND THAT CHRONIC PSYCHOGENIC STRESS INDUCED EPIGENETIC CHANGES IN THE HIPPOCAMPUS OF MICE WITH ENDOMETRIOSIS, AND SEEMINGLY ACTIVATED THE ADRENERGIC SIGNALLING IN ECTOPIC ENDOMETRIUM, RESULTING IN INCREASED ANGIOGENESIS AND ACCELERATED GROWTH OF ENDOMETRIOTIC LESIONS. THUS, CHRONIC PSYCHOGENIC STRESS PROMOTES ENDOMETRIOSIS DEVELOPMENT, RAISING THE POSSIBILITY THAT THE USE OF ANTI-DEPRESSANTS IN CASES OF PROLONGED AND INTENSE STRESS MIGHT FORESTALL THE NEGATIVE IMPACT OF STRESS ON THE DEVELOPMENT OF ENDOMETRIOSIS. 2017 10 5067 36 PHYSICAL ACTIVITY AND DNA METHYLATION IN HUMANS. PHYSICAL ACTIVITY IS A STRONG STIMULUS INFLUENCING THE OVERALL PHYSIOLOGY OF THE HUMAN BODY. EXERCISES LEAD TO BIOCHEMICAL CHANGES IN VARIOUS TISSUES AND EXERT AN IMPACT ON GENE EXPRESSION. EXERCISE-INDUCED CHANGES IN GENE EXPRESSION MAY BE MEDIATED BY EPIGENETIC MODIFICATIONS, WHICH REARRANGE THE CHROMATIN STRUCTURE AND THEREFORE MODULATE ITS ACCESSIBILITY FOR TRANSCRIPTION FACTORS. ONE OF SUCH EPIGENETIC MARK IS DNA METHYLATION THAT INVOLVES AN ATTACHMENT OF A METHYL GROUP TO THE FIFTH CARBON OF CYTOSINE RESIDUE PRESENT IN CG DINUCLEOTIDES (CPG). DNA METHYLATION IS CATALYZED BY A FAMILY OF DNA METHYLTRANSFERASES. THIS REVERSIBLE DNA MODIFICATION RESULTS IN THE RECRUITMENT OF PROTEINS CONTAINING METHYL BINDING DOMAIN AND FURTHER TRANSCRIPTIONAL CO-REPRESSORS LEADING TO THE SILENCING OF GENE EXPRESSION. THE ACCUMULATION OF CPG DINUCLEOTIDES, REFERRED AS CPG ISLANDS, OCCURS AT THE PROMOTER REGIONS IN A GREAT MAJORITY OF HUMAN GENES. THEREFORE, CHANGES IN DNA METHYLATION PROFILE AFFECT THE TRANSCRIPTION OF MULTIPLE GENES. A GROWING BODY OF EVIDENCE INDICATES THAT EXERCISE TRAINING MODULATES DNA METHYLATION IN MUSCLES AND ADIPOSE TISSUE. SOME OF THESE EPIGENETIC MARKERS WERE ASSOCIATED WITH A REDUCED RISK OF CHRONIC DISEASES. THIS REVIEW SUMMARIZES THE CURRENT KNOWLEDGE ABOUT THE INFLUENCE OF PHYSICAL ACTIVITY ON THE DNA METHYLATION STATUS IN HUMANS. 2021 11 2022 41 EPIGENETIC CHANGES ASSOCIATED WITH DISEASE PROGRESSION IN A MOUSE MODEL OF CHILDHOOD ALLERGIC ASTHMA. DEVELOPMENT OF ASTHMA IN CHILDHOOD IS LINKED TO VIRAL INFECTIONS OF THE LOWER RESPIRATORY TRACT IN EARLY LIFE, WITH SUBSEQUENT CHRONIC EXPOSURE TO ALLERGENS. PROGRESSION TO PERSISTENT ASTHMA IS ASSOCIATED WITH A TH2-BIASED IMMUNOLOGICAL RESPONSE AND STRUCTURAL REMODELLING OF THE AIRWAYS. THE UNDERLYING MECHANISMS ARE UNCLEAR, BUT COULD INVOLVE EPIGENETIC CHANGES. TO INVESTIGATE THIS, WE EMPLOYED A RECENTLY DEVELOPED MOUSE MODEL IN WHICH SELF-LIMITED NEONATAL INFECTION WITH A PNEUMOVIRUS, FOLLOWED BY SENSITISATION TO OVALBUMIN VIA THE RESPIRATORY TRACT AND LOW-LEVEL CHRONIC CHALLENGE WITH AEROSOLISED ANTIGEN, LEADS TO DEVELOPMENT OF AN ASTHMATIC PHENOTYPE. WE ASSESSED EXPRESSION OF MICRORNA BY CELLS IN THE PROXIMAL AIRWAYS, COMPARING CHANGES OVER THE PERIOD OF DISEASE PROGRESSION, AND USED TARGET PREDICTION DATABASES TO IDENTIFY GENES LIKELY TO BE UP- OR DOWNREGULATED AS A CONSEQUENCE OF ALTERED REGULATION OF MICRORNA. IN PARALLEL, WE ASSESSED DNA METHYLATION IN PULMONARY CD4(+) T CELLS. WE FOUND THAT A LIMITED NUMBER OF MICRORNAS EXHIBITED MARKED UP- OR DOWNREGULATION FOLLOWING EARLY-LIFE INFECTION AND SENSITISATION, FOR MANY OF WHICH THE LEVELS OF EXPRESSION WERE FURTHER CHANGED FOLLOWING CHRONIC CHALLENGE WITH THE SENSITIZING ANTIGEN. TARGETS OF THESE MICRORNAS INCLUDED GENES INVOLVED IN IMMUNE OR INFLAMMATORY RESPONSES (E.G. GATA3, KITL) AND IN TISSUE REMODELLING (E.G. IGF1, TGFBR1), AS WELL AS GENES FOR VARIOUS TRANSCRIPTION FACTORS AND SIGNALLING PROTEINS. IN PULMONARY CD4(+) T CELLS, THERE WAS SIGNIFICANT DEMETHYLATION AT PROMOTER SITES FOR INTERLEUKIN-4 AND INTERFERON-GAMMA, THE LATTER INCREASING FOLLOWING CHRONIC CHALLENGE. WE CONCLUDE THAT, IN THIS MODEL, PROGRESSION TO AN ASTHMATIC PHENOTYPE IS LINKED TO EPIGENETIC REGULATION OF GENES ASSOCIATED WITH INFLAMMATION AND STRUCTURAL REMODELLING, AND WITH T-CELL COMMITMENT TO A TH2 IMMUNOLOGICAL RESPONSE. EPIGENETIC CHANGES ASSOCIATED WITH THIS PATTERN OF GENE ACTIVATION MIGHT PLAY A ROLE IN THE DEVELOPMENT OF CHILDHOOD ASTHMA. 2013 12 2119 34 EPIGENETIC HISTONE MODIFICATION REGULATES DEVELOPMENTAL LEAD EXPOSURE INDUCED HYPERACTIVITY IN RATS. LEAD (PB) EXPOSURE WAS COMMONLY CONSIDERED AS A HIGH ENVIRONMENTAL RISK FACTOR FOR THE DEVELOPMENT OF ATTENTION-DEFICIT/HYPERACTIVITY DISORDER (ADHD). HOWEVER, THE MOLECULAR BASIS OF THIS PATHOLOGICAL PROCESS STILL REMAINS ELUSIVE. IN LIGHT OF THE ROLE OF EPIGENETICS IN MODULATING THE NEUROLOGICAL DISEASE AND THE CAUSATIVE ENVIRONMENT, THE ALTERATIONS OF HISTONE MODIFICATIONS IN THE HIPPOCAMPUS OF RATS EXPOSED BY VARIOUS DOSES OF LEAD, ALONG WITH CONCOMITANT BEHAVIORAL DEFICITS, WERE INVESTIGATED IN THIS STUDY. ACCORDING TO THE FREE AND FORCED OPEN FIELD TEST, THERE SHOWED THAT IN A DOSAGE-DEPENDENT MANNER, LEAD EXPOSURE COULD RESULT IN THE INCREASED LOCOMOTOR ACTIVITY OF RATS, THAT IS, HYPERACTIVITY: A SUBTYPE OF ADHD. WESTERN BLOTTING ASSAYS REVEALED THAT THE LEVELS OF HISTONE ACETYLATION INCREASED SIGNIFICANTLY IN THE HIPPOCAMPUS BY CHRONIC LEAD EXPOSURE, WHILE NO DRAMATIC CHANGES WERE DETECTED IN TERMS OF EXPRESSION YIELDS OF ADHD-RELATED DOPAMINERGIC PROTEINS, INDICATING THAT HISTONE ACETYLATION PLAYS ESSENTIAL ROLES IN THIS TOXICANT-INVOLVED PATHOGENESIS. IN ADDITION, THE INCREASED LEVEL OF HISTONE ACETYLATION MIGHT BE ATTRIBUTED TO THE ENZYMATIC ACTIVITY OF P300, A TYPICAL HISTONE ACETYLTRANSFERASE, AS THE TRANSCRIPTIONAL LEVEL OF P300 WAS SIGNIFICANTLY INCREASED UPON HIGHER-DOSE PB EXPOSURE. IN SUMMARY, THIS STUDY FIRST DISCOVERED THE EPIGENETIC MECHANISM BRIDGING THE ENVIRONMENTAL INFLUENCE (PB) AND THE DISEASE ITSELF (ADHD) IN THE HISTONE MODIFICATION LEVEL, PAVING THE WAY FOR THE COMPREHENSIVE UNDERSTANDING OF ADHD'S ETIOLOGY AND IN FURTHER STEPS, ESTABLISHING THE THERAPY STRATEGY OF THIS WIDESPREAD NEUROLOGICAL DISORDER. 2014 13 978 41 CHRONIC OXIDATIVE STRESS CAUSES ESTROGEN-INDEPENDENT AGGRESSIVE PHENOTYPE, AND EPIGENETIC INACTIVATION OF ESTROGEN RECEPTOR ALPHA IN MCF-7 BREAST CANCER CELLS. THE ROLE OF CHRONIC OXIDATIVE STRESS IN THE DEVELOPMENT AND AGGRESSIVE GROWTH OF ESTROGEN RECEPTOR (ER)-POSITIVE BREAST CANCER IS WELL KNOWN; HOWEVER, THE MECHANISTIC UNDERSTANDING IS NOT CLEAR. ESTROGEN-INDEPENDENT GROWTH IS ONE OF THE FEATURES OF AGGRESSIVE SUBTYPE OF BREAST CANCER. THEREFORE, THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE EFFECT OF OXIDATIVE STRESS ON ESTROGEN SENSITIVITY AND EXPRESSION OF NUCLEAR ESTROGEN RECEPTORS IN ER-POSITIVE BREAST CANCER CELLS. MCF-7 CELLS CHRONICALLY EXPOSED TO HYDROGEN PEROXIDE WERE USED AS A CELL MODEL IN THIS STUDY, AND THEIR GROWTH IN RESPONSE TO 17-BETA ESTRADIOL WAS EVALUATED BY CELL VIABILITY, CELL CYCLE, AND CELL MIGRATION ANALYSIS. RESULTS WERE FURTHER CONFIRMED AT MOLECULAR LEVEL BY ANALYSIS OF GENE EXPRESSIONS AT TRANSCRIPT AND PROTEIN LEVELS. HISTONE H3 MODIFICATIONS, EXPRESSION OF EPIGENETIC REGULATORY GENES, AND THE EFFECT OF DNA DEMETHYLATION WERE ALSO ANALYZED. LOSS OF GROWTH IN RESPONSE TO ESTROGEN WITH A DECREASE IN ERALPHA EXPRESSION WAS OBSERVED IN MCF-7 CELLS ADAPTED TO CHRONIC OXIDATIVE STRESS. INCREASES IN MTTFA AND NRF1 IN THESE CELLS FURTHER SUGGESTED THE ROLE OF MITOCHONDRIA-DEPENDENT REDOX-SENSITIVE GROWTH SIGNALING AS AN ALTERNATIVE PATHWAY TO ESTROGEN-DEPENDENT GROWTH. CHANGES IN EXPRESSION OF EPIGENETIC REGULATORY GENES, LEVELS OF HISTONE H3 MODIFICATIONS AS WELL AS SIGNIFICANT RESTORATIONS OF BOTH ERALPHA EXPRESSION AND ESTROGEN RESPONSE BY 5-AZA-2'-DEOXYCYTIDINE FURTHER CONFIRMED THE EPIGENETIC BASIS FOR ESTROGEN-INDEPENDENT GROWTH IN THESE CELLS. IN CONCLUSION, RESULTS OF THIS STUDY SUGGEST THAT CHRONIC OXIDATIVE STRESS CAN CONVERT ESTROGEN-DEPENDENT NONAGGRESSIVE BREAST CANCER CELLS INTO ESTROGEN-INDEPENDENT AGGRESSIVE FORM POTENTIALLY BY EPIGENETIC MECHANISM. 2015 14 5972 25 TET REPRESSION AND INCREASED DNMT ACTIVITY SYNERGISTICALLY INDUCE ABERRANT DNA METHYLATION. CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN VARIOUS HUMAN DISORDERS, SUCH AS CANCER, NEURODEGENERATIVE DISORDERS, AND METABOLIC DISORDERS. INDUCTION OF EPIGENETIC ALTERATIONS, ESPECIALLY ABERRANT DNA METHYLATION, IS ONE OF THE MAJOR MECHANISMS, BUT HOW IT IS INDUCED IS STILL UNCLEAR. HERE, WE FOUND THAT EXPRESSION OF TET GENES, METHYLATION ERASERS, WAS DOWNREGULATED IN INFLAMED MOUSE AND HUMAN TISSUES, AND THAT THIS WAS CAUSED BY UPREGULATION OF TET-TARGETING MIRNAS SUCH AS MIR20A, MIR26B, AND MIR29C, LIKELY DUE TO ACTIVATION OF NF-KAPPAB SIGNALING DOWNSTREAM OF IL-1BETA AND TNF-ALPHA. HOWEVER, TET KNOCKDOWN INDUCED ONLY MILD ABERRANT METHYLATION. NITRIC OXIDE (NO), PRODUCED BY NOS2, ENHANCED ENZYMATIC ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), METHYLATION WRITERS, AND NO EXPOSURE INDUCED MINIMAL ABERRANT METHYLATION. IN CONTRAST, A COMBINATION OF TET KNOCKDOWN AND NO EXPOSURE SYNERGISTICALLY INDUCED ABERRANT METHYLATION, INVOLVING GENOMIC REGIONS NOT METHYLATED BY EITHER ALONE. THE RESULTS SHOWED THAT A VICIOUS COMBINATION OF TET REPRESSION, DUE TO NF-KAPPAB ACTIVATION, AND DNMT ACTIVATION, DUE TO NO PRODUCTION, IS RESPONSIBLE FOR ABERRANT METHYLATION INDUCTION IN HUMAN TISSUES. 2020 15 3047 40 GENOME-WIDE ANALYSIS OF DNA METHYLATION IN ENDOMETRIOSIS USING ILLUMINA HUMAN METHYLATION 450 K BEADCHIPS. ENDOMETRIOSIS IS A COMMON CHRONIC GYNECOLOGIC DISORDER CHARACTERIZED BY THE PRESENCE AND GROWTH OF ENDOMETRIAL-LIKE TISSUE OUTSIDE OF THE UTERINE CAVITY. ALTHOUGH THE EXACT ETIOLOGY REMAINS UNCLEAR, EPIGENETIC MODIFICATIONS, SUCH AS DNA METHYLATION, ARE THOUGHT TO CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. HERE, WE USED THE ILLUMINA HUMAN METHYLATION 450 K BEADCHIP ARRAY TO ANALYZE THE GENOME-WIDE DNA METHYLATION PROFILES OF SIX ENDOMETRIOTIC LESIONS AND SIX EUTOPIC ENDOMETRIA FROM PATIENTS WITH OVARIAN ENDOMETRIOSIS AND SIX ENDOMETRIA OF WOMEN WITHOUT ENDOMETRIOSIS. COMPARED WITH THE EUTOPIC ENDOMETRIA OF WOMEN WITH ENDOMETRIOSIS, 12,159 DIFFERENTIALLY METHYLATED CPG SITES AND 375 DIFFERENTIALLY METHYLATED PROMOTER REGIONS WERE IDENTIFIED IN ENDOMETRIOTIC LESIONS. GO ANALYSES SHOWED THAT THESE PUTATIVE DIFFERENTIALLY METHYLATED GENES WERE PRIMARILY ASSOCIATED WITH IMMUNE RESPONSE, INFLAMMATORY RESPONSE, RESPONSE TO STEROID HORMONE STIMULUS, CELL ADHESION, NEGATIVE REGULATION OF APOPTOSIS, AND ACTIVATION OF THE MAPK ACTIVITY. IN ADDITION, THE EXPRESSION LEVELS OF DNMT1, DNMT3A, DNMT3B, AND MBD2 IN ENDOMETRIOTIC LESIONS AND EUTOPIC ENDOMETRIA WERE SIGNIFICANTLY DECREASED COMPARED WITH CONTROL ENDOMETRIA. OUR FINDINGS SUGGEST THAT ABERRANT DNA METHYLATION STATUS IN ENDOMETRIOTIC LESIONS MAY PLAY A SIGNIFICANT ROLE IN THE PATHOGENESIS AND PROGRESSION OF ENDOMETRIOSIS. 2019 16 3667 32 INFILTRATING MACROPHAGES INDUCE ERALPHA EXPRESSION THROUGH AN IL17A-MEDIATED EPIGENETIC MECHANISM TO SENSITIZE ENDOMETRIAL CANCER CELLS TO ESTROGEN. PERSISTENT UNOPPOSED ESTROGEN STIMULATION IS A CENTRAL ONCOGENIC MECHANISM DRIVING THE FORMATION OF TYPE I ENDOMETRIAL CANCER. RECENT EPIDEMIOLOGIC AND CLINICAL STUDIES OF ENDOMETRIAL CANCER HAVE ALSO REVEALED A ROLE FOR INSULIN RESISTANCE, CLINICALLY MANIFESTED BY CHRONIC INFLAMMATION. HOWEVER, THE ROLE OF INFLAMMATION IN ESTROGEN-DRIVEN ENDOMETRIAL CANCER IS NOT WELL CHARACTERIZED. IN THIS STUDY, WE INVESTIGATED THE ASSOCIATION BETWEEN INFILTRATING MACROPHAGES AND ESTROGEN SENSITIVITY IN ENDOMETRIAL CANCER. EVALUATING TISSUE SAMPLES AND SERUM FROM PATIENTS WITH PRECANCEROUS LESIONS OR ENDOMETRIAL CANCER, WE FOUND THAT TISSUE MACROPHAGE INFILTRATION, BUT NOT SERUM ESTRADIOL LEVELS, CORRELATED POSITIVELY WITH ENDOMETRIAL CANCER DEVELOPMENT. FURTHERMORE, IL4/IL13-INDUCED CD68(+)CD163(+) MACROPHAGES ENHANCED THE PROLIFERATIVE EFFECTS OF ESTRADIOL IN ENDOMETRIAL CANCER CELLS BY UPREGULATING ESTROGEN RECEPTOR ALPHA (ERALPHA), BUT NOT ERBETA. MECHANISTIC INVESTIGATIONS REVEALED THAT CD68(+)CD163(+) MACROPHAGES SECRETED CYTOKINES, SUCH AS IL17A, THAT UPREGULATED ERALPHA EXPRESSION THROUGH TET1-MEDIATED EPIGENETIC MODULATION OF THE ERALPHA GENE. OVERALL, OUR FINDINGS SHOW HOW CYTOKINES PRODUCED BY INFILTRATING MACROPHAGES IN THE ENDOMETRIAL MICROENVIRONMENT CAN INDUCE EPIGENETIC UPREGULATION OF ERALPHA EXPRESSION, WHICH IN TURN SENSITIZES ENDOMETRIAL CELLS TO ESTROGEN STIMULATION. THE CONCEPT THAT INFLAMMATION-INDUCED ESTROGEN SENSITIVITY IN THE ENDOMETRIUM ACTS AS A DRIVER OF TYPE I ENDOMETRIAL CANCER HAS IMPLICATIONS FOR INFILTRATING MACROPHAGES AS A PROGNOSTIC BIOMARKER OF PROGRESSION IN THIS DISEASE SETTING. 2016 17 898 35 CHRONIC EXPOSURE OF MICE TO BISPHENOL-A ALTERS UTERINE FIBROBLAST GROWTH FACTOR SIGNALING AND LEADS TO ABERRANT EPITHELIAL PROLIFERATION. UTERINE EPITHELIAL PROLIFERATION IS REGULATED IN A PARACRINE MANNER BY A COMPLEX INTERPLAY BETWEEN ESTROGEN (E) AND PROGESTERONE (P) SIGNALING, IN WHICH E STIMULATES PROLIFERATION AND P INHIBITS IT. PERTURBATION OF STEROID HORMONE SIGNALING WITHIN THE UTERINE MILIEU COULD CONTRIBUTE TO THE DEVELOPMENT OF ENDOMETRIAL HYPERPLASIA AND CANCER. IT IS WELL ESTABLISHED THAT BISPHENOL-A (BPA) IS AN ENDOCRINE-DISRUPTING CHEMICAL WITH WEAK ESTROGENIC EFFECTS, ALTHOUGH LITTLE IS KNOWN ABOUT HOW IT AFFECTS STEROID HORMONE SIGNALING IN THE ADULT UTERUS. BECAUSE BPA ACTS AS A WEAK E, WE HYPOTHESIZED THAT CHRONIC EXPOSURE TO BPA WOULD CREATE AN IMBALANCE BETWEEN E AND P SIGNALING AND CAUSE CHANGES IN THE UTERUS, SUCH AS ABERRANT EPITHELIAL PROLIFERATION. INDEED, EXPOSURE TO AN ENVIRONMENTALLY RELEVANT DOSE OF BPA HAD A UTEROTROPHIC AFFECT. BPA-TREATED MICE SHOWED INCREASED PROLIFERATION, NOTABLY IN THE GLANDULAR EPITHELIUM, WHICH ARE SITES OF ORIGIN FOR ENDOMETRIAL HYPERPLASIA AND CANCER. INCREASED PROLIFERATION APPEARED TO BE MEDIATED THROUGH A SIMILAR MECHANISM AS E-INDUCED PROLIFERATION, VIA ACTIVATION OF THE FIBROBLAST GROWTH FACTOR RECEPTOR PATHWAY AND PHOSPHORYLATION OF THE ERK1/2 MITOGEN-ACTIVATED PROTEIN KINASES IN THE EPITHELIUM. INTERESTINGLY, BPA REDUCED EXPRESSION OF HEART AND NEURAL CREST DERIVATIVES EXPRESSED 2 (HAND2), A KNOWN MEDIATOR OF THE ANTIPROLIFERATIVE EFFECTS OF P. BPA ALSO INCREASED METHYLATION OF A CPG ISLAND IN THE HAND2 GENE PROMOTER, SUGGESTING THAT BPA MAY PROMOTE EPITHELIAL PROLIFERATION THROUGH EPIGENETIC SILENCING OF ANTIPROLIFERATIVE FACTORS LIKE HAND2. COLLECTIVELY, THESE FINDINGS ESTABLISH THAT CHRONIC EXPOSURE TO BPA IMPAIRS STEROID HORMONE SIGNALING IN THE MOUSE UTERUS, AND MAY CONTRIBUTE TO THE PATHOGENESIS OF UTERINE HYPERPLASIA AND CANCER. 2019 18 2747 44 EXPRESSION ANALYSIS OF THE EPIGENETIC METHYLTRANSFERASES AND METHYL-CPG BINDING PROTEIN FAMILIES IN THE NORMAL B-CELL AND B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). THE IMPORTANCE OF EPIGENETIC MODIFICATIONS IN CARCINOGENESIS HAS BEEN A SOURCE OF CONTROVERSY FOR SOME TIME. THERE IS LITTLE DOUBT THAT CHANGES IN GENOMIC HYPERMETHYLATION CONTRIBUTE TO THE SILENCING OF TUMOR SUPPRESSOR GENES. FURTHERMORE, RECENT STUDIES HAVE ALSO IDENTIFIED THE SIGNIFICANCE OF GENOMIC HYPOMETHYLATION ASSOCIATED WITH CHROMOSOMAL INSTABILITY AND TUMORIGENESIS. ONE OF THE MOST PERPLEXING QUESTIONS REGARDING EPIGENETIC MODIFICATIONS AND LEUKEMOGENESIS IS THE RELATIONSHIP WITH DNA METHYLTRANSFERASES (DNMT'S). THE PRIMARY FUNCTION OF THE DNMT ENZYMES IS TO METHYLATE GENOMIC DNA, WHEREAS THE METHYL-CPG BINDING DOMAIN PROTEINS (MBD) INTERPRET THIS METHYLATION SIGNAL AND REGULATE GENE EXPRESSION AND CHROMATIN BEHAVIOR. IN THIS STUDY WE ANALYSE THESE GENE FAMILIES BY QUANTITATIVE REAL-TIME PCR TO INVESTIGATE WHETHER EXPRESSION LEVELS AND THE B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL) PHENOTYPE ARE ASSOCIATED. FURTHERMORE, GIVEN THE EPIGENETIC CROSSTALK BETWEEN GENOME STABILITY AND THE HISTONE CHROMATIN CODE WE HAVE ANALYSED EUKARYOTIC HISTONE METHYLTRANSFERASE (EU-HMTASEI). SURPRISINGLY, WE DID NOT OBSERVE SIGNIFICANT CHANGES IN DNMT1 EXPRESSION IN B-CLL CASES WHEN COMPARED TO NORMAL LYMPHOCYTES, REGARDLESS OF WHETHER WE NORMALISE AGAINST GAPDH OR PCNA AS REFERENCE STANDARDS. INDEED, EXPRESSION OF THE MAINTENANCE AND DE NOVO METHYLASES WERE INDEPENDENTLY REGULATED. OF PARTICULAR NOTE WAS THE SIGNIFICANT DOWN REGULATION OF DNMT3B. FURTHERMORE, WE OBSERVED A POSITIVE CORRELATION BETWEEN HMTASEI EXPRESSION LEVELS AND STAGE OF LEUKEMIA SUGGESTING THAT CHANGES IN THE METHYLATION PATTERNS IN B-CLL MAY REPRESENT DEREGULATION OF THE EPIGENETIC REPERTOIRE THAT ALSO INCLUDE THE METHYLATION DEPENDENT BINDING PROTEINS, MBD2 AND MECP2. WE ENVISAGE CHANGES IN THE EPIGENETIC PROGRAM ARE MULTIFACTORIAL IN NATURE AND POSTULATE THAT THE PREVALENT GENOMIC METHYLASES JUST ONE COMPONENT OF A LARGER EPIGENETIC REPERTOIRE. 2004 19 3726 33 INHIBITION OF HISTONE METHYLTRANSFERASE EZH2 SUPPRESSES ENDOMETRIOTIC VESICLE DEVELOPMENT IN A RAT MODEL OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A PAINFUL GYNECOLOGICAL DISEASE WITH NO CURE AND LIMITED THERAPEUTIC OPTIONS. IT HAS BEEN HYPOTHESIZED THAT EPIGENETIC DRUGS CAN BE USED AS A NONHORMONAL TREATMENT FOR ENDOMETRIOSIS. THIS STUDY WAS CONDUCTED TO STUDY THE EFFICACY OF AN INHIBITOR OF THE HISTONE METHYLTRANSFERASE EZH2 USING AN ESTABLISHED RAT MODEL OF ENDOMETRIOSIS. WE HYPOTHESIZED THAT TREATMENT WILL BLOCK OR REDUCE THE NUMBER OF ENDOMETRIOTIC VESICLES IN THIS MODEL. WE CONDUCTED A PRECLINICAL DRUG STUDY IN FEMALE RATS WITH EXPERIMENTAL ENDOMETRIOSIS (UTERINE TISSUE TRANSPLANTED NEXT TO THE INTESTINAL MESENTERY) OR CONTROL SHAM (SUTURES ONLY). RATS WITH ENDOMETRIOSIS OR SHAM SURGERY RECEIVED EITHER TREATMENT WITH EZH2 INHIBITOR (5 MG/KG OR 10 MG/KG) OR VEHICLE (0.1%, 67% DMSO) EVERY OTHER DAY DURING 4 WEEKS. AFTER TREATMENT COMPLETION, THE NUMBER, AREA, VOLUME, AND WEIGHT OF VESICLES WERE EVALUATED. RT [2] PROFILER ARRAYS FOR NEUROPATHIC AND INFLAMMATION, EPITHELIAL TO MESENCHYMAL TRANSITION, INFLAMMATORY RESPONSE, AND AUTOIMMUNITY PATHWAYS WERE USED TO EXAMINE GENE EXPRESSION CHANGES IN THE VESICLES THAT DEVELOPED. TREATMENT WITH EZH2 INHIBITOR (10 MG/KG) SUPPRESSED THE DEVELOPMENT OF VESICLES, BY SIGNIFICANTLY DECREASING THE TOTAL VESICLE NUMBER, AREA, VOLUME, AND WEIGHT. IN ADDITION, EZH2 INHIBITION SIGNIFICANTLY INCREASED THE EXPRESSION OF CACNA1B AND FKBP1A GENES, INVOLVED IN PAIN AND PROLIFERATION, RESPECTIVELY. EZH2 INHIBITION SUPPRESSES THE GROWTH OF VESICLES WITHOUT APPARENT DETRIMENTAL EFFECTS TO OTHER ORGANS. TREATMENT WITH THIS EPIGENETIC INHIBITOR LEADS TO UPREGULATION OF A LIMITED NUMBER OF GENES RELATED TO ENDOMETRIOSIS-RELEVANT PATHWAYS. IN CONCLUSION, THESE DATA SUPPORT FOLLOW-UP STUDIES TO EVALUATE ITS POTENTIAL AS A THERAPEUTIC APPROACH FOR ENDOMETRIOSIS. 2020 20 1202 43 COULD DNA HYDROXYMETHYLATION BE CRUCIAL IN INFLUENCING STEROID HORMONE SIGNALING IN ENDOMETRIAL BIOLOGY AND ENDOMETRIOSIS? ENDOMETRIOSIS AFFECTS 10% OF REPRODUCTIVE-AGED WOMEN. IT IS CHARACTERIZED BY THE GROWTH OF THE ENDOMETRIUM, OUTSIDE THE UTERUS AND IS ASSOCIATED WITH INFERTILITY AND CHRONIC ABDOMINAL PAIN. LACK OF NONINVASIVE DIAGNOSTIC TOOLS AND EARLY SCREENING TESTS RESULTS IN DELAYED TREATMENT AND SUBSEQUENTLY INCREASED DISEASE SEVERITY. ENDOMETRIOSIS IS A DISEASE ASSOCIATED WITH A DEREGULATED HORMONAL RESPONSE, THEREFORE, UNDERSTANDING THE MOLECULAR MECHANISMS THAT GOVERN THIS HORMONAL INTERPLAY IS OF PARAMOUNT IMPORTANCE. DNA METHYLATION IS AN EPIGENETIC MARK THAT REGULATES GENE EXPRESSION AND IS OFTEN ASSOCIATED WITH GENES THAT CODE FOR STEROID RECEPTORS AND ENZYMES ASSOCIATED WITH ESTROGEN SYNTHESIS AND METABOLISM IN ENDOMETRIOSIS. DNA HYDROXYMETHYLATION, WHICH IS STRUCTURALLY SIMILAR TO METHYLATION BUT FUNCTIONALLY DIFFERENT, IS A BIOLOGICALLY CRITICAL MECHANISM THAT IS ALSO KNOWN TO REGULATE GENE EXPRESSION. TEN ELEVEN TRANSLOCATION (TET) PROTEINS MEDIATE HYDROXYMETHYLATION. HOWEVER, THE ROLE OF DNA HYDROXYMETHYLATION OR TETS IN THE ENDOMETRIUM REMAINS RELATIVELY UNEXPLORED. CURRENTLY, THE "GOLD STANDARD" TECHNIQUE USED TO STUDY METHYLATION PATTERNS IS BISULFITE GENOMIC SEQUENCING. THIS TECHNIQUE ALSO DETECTS HYDROXYMETHYLATION BUT FAILS TO DISTINGUISH BETWEEN THE TWO, THEREBY LIMITING OUR UNDERSTANDING OF THESE TWO PROCESSES. THE PRESENCE OF TETS IN THE MALE AND FEMALE REPRODUCTIVE TRACT AND ITS CONTRIBUTION TO ENDOMETRIAL CANCER MAKES IT AN IMPORTANT FACTOR TO STUDY IN ENDOMETRIOSIS. THIS REVIEW SUMMARIZES THE ROLE OF DNA METHYLATION IN ABERRANT STEROID HORMONE SIGNALING AND HYPOTHESIZES THAT HYDROXYMETHYLATION COULD BE A FACTOR INFLUENCING HORMONAL INSTABILITY SEEN IN ENDOMETRIOSIS. 2020