1 5981 142 TET2 PROMOTES PATHOGEN INFECTION-INDUCED MYELOPOIESIS THROUGH MRNA OXIDATION. VARIETIES OF RNA MODIFICATION FORM THE EPITRANSCRIPTOME FOR POST-TRANSCRIPTIONAL REGULATION. 5-METHYLCYTOSINE (5-MC) IS A SPARSE RNA MODIFICATION IN MESSENGER RNA (MRNA) UNDER PHYSIOLOGICAL CONDITIONS. THE FUNCTION OF RNA 5-HYDROXYMETHYLCYTOSINE (5-HMC) OXIDIZED BY TEN-ELEVEN TRANSLOCATION (TET) PROTEINS IN DROSOPHILA HAS BEEN REVEALED MORE RECENTLY. HOWEVER, THE TURNOVER AND FUNCTION OF 5-MC IN MAMMALIAN MRNA HAVE BEEN LARGELY UNKNOWN. TET2 SUPPRESSES MYELOID MALIGNANCIES MOSTLY IN AN ENZYMATIC ACTIVITY-DEPENDENT MANNER, AND IS IMPORTANT IN RESOLVING INFLAMMATORY RESPONSE IN AN ENZYMATIC ACTIVITY-INDEPENDENT WAY. MYELOPOIESIS IS A COMMON HOST IMMUNE RESPONSE IN ACUTE AND CHRONIC INFECTIONS; HOWEVER, ITS EPIGENETIC MECHANISM NEEDS TO BE IDENTIFIED. HERE WE DEMONSTRATE THAT TET2 PROMOTES INFECTION-INDUCED MYELOPOIESIS IN AN MRNA OXIDATION-DEPENDENT MANNER THROUGH ADAR1-MEDIATED REPRESSION OF SOCS3 EXPRESSION AT THE POST-TRANSCRIPTION LEVEL. TET2 PROMOTES BOTH ABDOMINAL SEPSIS-INDUCED EMERGENCY MYELOPOIESIS AND PARASITE-INDUCED MAST CELL EXPANSION THROUGH DECREASING MRNA LEVELS OF SOCS3, A KEY NEGATIVE REGULATOR OF THE JAK-STAT PATHWAY THAT IS CRITICAL FOR CYTOKINE-INDUCED MYELOPOIESIS. TET2 REPRESSES SOCS3 EXPRESSION THROUGH ADAR1, WHICH BINDS AND DESTABILIZES SOCS3 MRNA IN A RNA EDITING-INDEPENDENT MANNER. FOR THE UNDERLYING MECHANISM OF TET2 REGULATION AT THE MRNA LEVEL, TET2 MEDIATES OXIDATION OF 5-MC IN MRNA. TET2 DEFICIENCY LEADS TO THE TRANSCRIPTOME-WIDE APPEARANCE OF METHYLATED CYTOSINES, INCLUDING ONES IN THE 3' UNTRANSLATED REGION OF SOCS3, WHICH INFLUENCES DOUBLE-STRANDED RNA FORMATION FOR ADAR1 BINDING, PROBABLY THROUGH CYTOSINE METHYLATION-SPECIFIC READERS, SUCH AS RNA HELICASES. OUR STUDY REVEALS A PREVIOUSLY UNKNOWN REGULATORY ROLE OF TET2 AT THE EPITRANSCRIPTOMIC LEVEL, PROMOTING MYELOPOIESIS DURING INFECTION IN THE MAMMALIAN SYSTEM BY DECREASING 5-MCS IN MRNAS. MOREOVER, THE INHIBITORY FUNCTION OF CYTOSINE METHYLATION ON DOUBLE-STRANDED RNA FORMATION AND ADAR1 BINDING IN MRNA REVEALS ITS NEW PHYSIOLOGICAL ROLE IN THE MAMMALIAN SYSTEM. 2018 2 5975 35 TET1 IS AN IMPORTANT TRANSCRIPTIONAL ACTIVATOR OF TNFALPHA EXPRESSION IN MACROPHAGES. ACTIVATION OF MACROPHAGES AND OVEREXPRESSION OF TNFALPHA IS ASSOCIATED WITH THE PATHOGENESIS OF CHRONIC INFLAMMATORY DISEASES. HOWEVER, THE MECHANISMS LEADING TO TNFALPHA OVEREXPRESSION ARE STILL UNKNOWN. 5-METHYLOCYTOSINE (5-MC) IS AN EPIGENETIC MODIFICATION THAT IS ASSOCIATED WITH SILENCED GENES. RECENT STUDIES SHOWED THAT IT IS CONVERTED TO 5-HYDROXYLMETHYLOCYTOSINE (5-HMC) AND REACTIVATES GENE EXPRESSION THROUGH THE ACTION OF THE FAMILY OF TEN-ELEVEN-TRANSLOCATION (TET1-3) ENZYMES. IN THIS STUDY, WE SHOW THAT 5-HMC LEVELS ARE INCREASED GLOBALLY AND SPECIFICALLY IN THE TNFALPHA PROMOTER DURING THE DIFFERENTIATION OF MONOCYTES TO MACROPHAGES. IN ADDITION, THE LEVELS OF 5-HMC ARE INCREASED UPON LPS STIMULATION OF MACROPHAGES. FURTHERMORE, CRIPSR STABLE KNOCKOUT OF TET1 DECREASES THE EXPRESSION OF TNFALPHA AND OTHER PRO-INFLAMMATORY CYTOKINES. IN CONCLUSION, WE SHOWED THAT TET1 CONTRIBUTES TO THE ACTIVATION OF MACROPHAGES POSSIBLY THROUGH REGULATION OF 5-HYDROXYMETHYLATION IN THE PROMOTER OF PRO-INFLAMMATORY CYTOKINE GENES. THE TET1 ENZYME COULD BE A PROMISING THERAPEUTIC TARGET TO INHIBIT THE PERSISTENT INFLAMMATION CAUSED BY MACROPHAGES IN CHRONIC INFLAMMATORY DISEASES. 2019 3 5972 26 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 4 3527 30 IL-6 ENHANCES THE NUCLEAR TRANSLOCATION OF DNA CYTOSINE-5-METHYLTRANSFERASE 1 (DNMT1) VIA PHOSPHORYLATION OF THE NUCLEAR LOCALIZATION SEQUENCE BY THE AKT KINASE. THE EPIGENETIC PROGRAMMING OF GENOMIC DNA IS ACCOMPLISHED, IN PART, BY SEVERAL DNA CYTOSINE-5-METHYLTRANSFERASES THAT ACT BY COVALENTLY MODIFYING CYTOSINES WITH THE ADDITION OF A METHYL GROUP. THIS COVALENT MODIFICATION IS MAINTAINED BY THE DNA CYTOSINE-5-METHYLTRANSFERASE-1 ENZYME (DNMT1), WHICH IS CAPABLE OF ACTING IN CONCERT WITH OTHER SIMILAR ENZYMES TO SILENCE IMPORTANT TUMOR SUPPRESSOR GENES. IL-6 IS A MULTIFUNCTIONAL MEDIATOR OF INFLAMMATION, ACTING THROUGH SEVERAL MAJOR SIGNALING CASCADES, INCLUDING THE PHOSPHATIDYLINOSITOL-3-KINASE PATHWAY (PI-3-K), WHICH ACTIVATES PROTEIN KINASE B (AKT/PKB) DOWNSTREAM. HERE, WE SHOW THAT THE SUBCELLULAR LOCALIZATION OF DNMT1 CAN BE ALTERED BY THE ADDITION OF IL-6, INCREASING THE RATE OF NUCLEAR TRANSLOCATION OF THE ENZYME FROM THE CYTOSOLIC COMPARTMENT. THE MECHANISM OF NUCLEAR TRANSLOCATION OF DNMT1 IS GREATLY ENHANCED BY PHOSPHORYLATION OF THE DNMT1 NUCLEAR LOCALIZATION SIGNAL (NLS) BY PKB/AKT KINASE. MUTAGENIC ALTERATION OF THE TWO AKT TARGET AMINO ACIDS WITHIN THE NLS RESULTS IN A MAJOR LOSS OF DNMT1 NUCLEAR TRANSLOCATION, WHILE THE CREATION OF A "PHOSPHO-MIMIC" AMINO ACID (MUTATION TO ACIDIC RESIDUES) RESTORES THIS COMPARTMENTATION ABILITY. THESE OBSERVATIONS SUGGEST AN INTERESTING HYPOTHESIS REGARDING HOW MEDIATORS OF CHRONIC INFLAMMATION MAY DISTURB THE DELICATE BALANCE OF CELLULAR COMPARTMENTALIZATION OF IMPORTANT PROTEINS, AND REVEALS A POTENTIAL MECHANISM FOR THE INDUCTION OR ENHANCEMENT OF TUMOR GROWTH VIA ALTERATION OF THE COMPONENTS INVOLVED IN THE EPIGENETIC PROGRAMMING OF A CELL. 2007 5 6419 42 THE TET2-UPF1 COMPLEX MODULATES MRNA STABILITY UNDER STRESS CONDITIONS. INTRODUCTION: ENVIRONMENTAL STRESS PROMOTES EPIGENETIC ALTERATIONS THAT IMPACT GENE EXPRESSION AND SUBSEQUENTLY PARTICIPATE IN THE PATHOLOGICAL PROCESSES OF THE DISORDER. AMONG EPIGENETIC REGULATIONS, TEN-ELEVEN TRANSLOCATION (TET) ENZYMES OXIDIZE 5-METHYLCYTOSINE (5MC) TO 5-HYDROXYMETHYLCYTOSINE (5HMC) IN DNA AND RNA AND FUNCTION AS CRITICAL PLAYERS IN THE PATHOGENESIS OF DISEASES. OUR PREVIOUS RESULTS SHOWED THAT CHRONIC STRESS INCREASES THE EXPRESSION OF CYTOPLASMIC TET2 IN THE HIPPOCAMPUS OF MICE EXPOSED TO CHRONIC MILD STRESS (CMS). WHETHER THE CYTOPLASMIC TET2 ALTERS RNA 5HMC MODIFICATION IN CHRONIC STRESS-RELATED PROCESSES REMAINS LARGELY UNKNOWN. METHODS: TO EXPLORE THE ROLE OF CYTOPLASMIC TET2 UNDER CMS CONDITIONS, WE ESTABLISHED CMS MICE MODEL AND DETECTED THE EXPRESSION OF RNA 5HMC BY DOT BLOT. WE VERIFIED THE INTERACTION OF TET2 AND ITS INTERACTING PROTEIN BY CO-IMMUNOPRECIPITATION COMBINED WITH MASS SPECTROMETRY AND SCREENED DOWNSTREAM TARGET GENES BY CLUSTER ANALYSIS OF TET2 AND UPSTREAM FRAMESHIFT 1 (UPF1) INTERACTING RNA. THE EXPRESSION OF PROTEIN WAS DETECTED BY WESTERN BLOT AND THE EXPRESSION OF THE SCREENED TARGET GENES WAS DETECTED BY QRT-PCR. RESULTS: IN THIS STUDY, WE FOUND THAT INCREASED CYTOPLASMIC TET2 EXPRESSION UNDER CMS CONDITIONS LEADS TO INCREASE IN TOTAL RNA 5HMC MODIFICATION. TET2 INTERACTED WITH THE KEY NON-SENSE-MEDIATED MRNA DECAY (NMD) FACTOR UPF1, REGULATED THE STABILITY OF STRESS-RELATED GENES SUCH AS UNC5B MRNA, AND MIGHT THEREBY AFFECT NEURODEVELOPMENT. DISCUSSION: IN SUMMARY, THIS STUDY REVEALED THAT TET2-MEDIATED RNA 5HMC MODIFICATION IS INVOLVED IN STRESS-RELATED MRNA STABILITY REGULATION AND MAY SERVE AS A POTENTIAL THERAPEUTIC TARGET FOR CHRONIC STRESS-RELATED DISEASES SUCH AS DEPRESSION. 2023 6 2055 31 EPIGENETIC CONTROL DURING LYMPHOID DEVELOPMENT AND IMMUNE RESPONSES: ABERRANT REGULATION, VIRUSES, AND CANCER. METHYLATION OF CYTOSINES CONTROLS A NUMBER OF BIOLOGIC PROCESSES SUCH AS IMPRINTING AND X CHROMOSOMAL INACTIVATION. DNA HYPERMETHYLATION IS CLOSELY ASSOCIATED WITH TRANSCRIPTIONAL SILENCING, WHILE DNA HYPOMETHYLATION IS ASSOCIATED WITH TRANSCRIPTIONAL ACTIVATION. HYPOACETYLATION OF HISTONES LEADS TO COMPACT CHROMATIN WITH REDUCED ACCESSIBILITY TO THE TRANSCRIPTIONAL MACHINERY. METHYL-CPG BINDING PROTEINS CAN RECRUIT COREPRESSORS AND HISTONE DEACETYLASES; THUS, THE INTERPLAY BETWEEN THESE EPIGENETIC MECHANISMS REGULATES GENE ACTIVATION. METHYLATION HAS BEEN IMPLICATED AS AN IMPORTANT MECHANISM DURING IMMUNE DEVELOPMENT, CONTROLLING VDJ RECOMBINATION, LINEAGE-SPECIFIC EXPRESSION OF CELL SURFACE ANTIGENS, AND TRANSCRIPTIONAL REGULATION OF CYTOKINE GENES DURING IMMUNE RESPONSES. ABERRATIONS IN EPIGENETIC MACHINERY, EITHER BY GENETIC MUTATIONS OR BY SOMATIC CHANGES SUCH AS VIRAL INFECTIONS, ARE ASSOCIATED WITH EARLY ALTERATIONS IN CHRONIC DISEASES SUCH AS IMMUNODEFICIENCY AND CANCER. 2003 7 3415 34 HSP90 INHIBITION INCREASES SOCS3 TRANSCRIPT AND REGULATES MIGRATION AND CELL DEATH IN CHRONIC LYMPHOCYTIC LEUKEMIA. EPIGENETIC OR TRANSCRIPTIONAL SILENCING OF IMPORTANT TUMOR SUPPRESSORS HAS BEEN DESCRIBED TO CONTRIBUTE TO CELL SURVIVAL AND TUMORIGENESIS IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). USING GENE EXPRESSION MICROARRAY ANALYSIS, WE FOUND THAT THOUSANDS OF GENES ARE REPRESSED MORE THAN 2-FOLD IN CLL COMPARED TO NORMAL B CELLS; HOWEVER THERAPEUTIC APPROACHES TO REVERSE THIS HAVE BEEN LIMITED IN CLL. FOLLOWING TREATMENT WITH THE HSP90 INHIBITOR 17-DMAG, A SIGNIFICANT NUMBER OF THESE REPRESSED GENES WERE SIGNIFICANTLY RE-EXPRESSED. ONE OF THE GENES SIGNIFICANTLY REPRESSED IN CLL AND UP-REGULATED BY 17-DMAG WAS SUPPRESSOR OF CYTOKINE SIGNALING 3, (SOCS3). SOCS3 HAS BEEN SHOWN TO BE SILENCED IN SOLID TUMORS AS WELL AS MYELOID LEUKEMIA; HOWEVER LITTLE IS KNOWN ABOUT THE REGULATION IN CLL. WE FOUND THAT 17-DMAG INDUCES EXPRESSION OF SOCS3 BY VIA THE ACTIVATION OF P38 SIGNALING, AND SUBSEQUENTLY INHIBITS AKT AND STAT3 PHOSPHORYLATION RESULTING IN DOWNSTREAM EFFECTS ON CELL MIGRATION AND SURVIVAL. WE THEREFORE SUGGEST THAT SOCS3 IS AN IMPORTANT SIGNALING PROTEIN IN CLL, AND HSP90 INHIBITORS REPRESENT A NOVEL APPROACH TO TARGET TRANSCRIPTIONAL REPRESSION IN B CELL LYMPHOPROLIFERATIVE DISORDERS WHICH EXHIBIT A SUBSTANTIAL DEGREE OF GENE REPRESSION. 2016 8 5971 35 TET PROTEINS AND 5-METHYLCYTOSINE OXIDATION IN HEMATOLOGICAL CANCERS. DNA METHYLATION HAS PIVOTAL REGULATORY ROLES IN MAMMALIAN DEVELOPMENT, RETROTRANSPOSON SILENCING, GENOMIC IMPRINTING, AND X-CHROMOSOME INACTIVATION. CANCER CELLS DISPLAY HIGHLY DYSREGULATED DNA METHYLATION PROFILES CHARACTERIZED BY GLOBAL HYPOMETHYLATION IN CONJUNCTION WITH HYPERMETHYLATION OF PROMOTER CPG ISLANDS THAT PRESUMABLY LEAD TO GENOME INSTABILITY AND ABERRANT EXPRESSION OF TUMOR SUPPRESSOR GENES OR ONCOGENES. THE RECENT DISCOVERY OF TEN-ELEVEN-TRANSLOCATION (TET) FAMILY DIOXYGENASES THAT OXIDIZE 5MC TO 5-HYDROXYMETHYLCYTOSINE (5HMC), 5-FORMYLCYTOSINE (5FC), AND 5-CARBOXYLCYTOSINE (5CAC) IN DNA HAS LED TO PROFOUND PROGRESS IN UNDERSTANDING THE MECHANISM UNDERLYING DNA DEMETHYLATION. AMONG THE THREE TET GENES, TET2 RECURRENTLY UNDERGOES INACTIVATING MUTATIONS IN A WIDE RANGE OF MYELOID AND LYMPHOID MALIGNANCIES. TET2 FUNCTIONS AS A BONA FIDE TUMOR SUPPRESSOR PARTICULARLY IN THE PATHOGENESIS OF MYELOID MALIGNANCIES RESEMBLING CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AND MYELODYSPLASTIC SYNDROMES (MDS) IN HUMAN. HERE WE REVIEW DIVERSE FUNCTIONS OF TET PROTEINS AND THE NOVEL EPIGENETIC MARKS THAT THEY GENERATE IN DNA METHYLATION/DEMETHYLATION DYNAMICS AND NORMAL AND MALIGNANT HEMATOPOIETIC DIFFERENTIATION. THE IMPACT OF TET2 INACTIVATION IN HEMATOPOIESIS AND VARIOUS MECHANISMS MODULATING THE EXPRESSION OR ACTIVITY OF TET PROTEINS ARE ALSO DISCUSSED. FURTHERMORE, WE ALSO PRESENT EVIDENCE THAT TET2 AND TET3 COLLABORATE TO SUPPRESS ABERRANT HEMATOPOIESIS AND HEMATOPOIETIC TRANSFORMATION. A DETAILED UNDERSTANDING OF THE NORMAL AND PATHOLOGICAL FUNCTIONS OF TET PROTEINS MAY PROVIDE NEW AVENUES TO DEVELOP NOVEL EPIGENETIC THERAPIES FOR TREATING HEMATOLOGICAL MALIGNANCIES. 2015 9 1542 38 DNA METHYLATION IN HAEMATOLOGICAL MALIGNANCIES: THE ROLE OF DECITABINE. NORMAL CELL DEVELOPMENT AND FUNCTION IS DEPENDENT UPON CONTROLLED GENE EXPRESSION. DNA METHYLATION IS AN EPIGENETIC MODIFICATION THAT CAN PLAY AN IMPORTANT ROLE IN THE CONTROL OF GENE EXPRESSION. DNA METHYLATION AT CYTOSINE RESIDUES IN GENE PROMOTER CPG SEQUENCES IS KNOWN TO INHIBIT GENE TRANSCRIPTION. INAPPROPRIATE INHIBITION OF THE TRANSCRIPTION OF TUMOUR SUPPRESSOR GENES, GENES THAT INHIBIT ANGIOGENESIS AND METASTASIS AND GENES INVOLVED IN DNA REPAIR BY UNCONTROLLED METHYLATION, CAN LEAD TO UNREGULATED GROWTH AND PROLIFERATION OF A CELL AND CARCINOGENESIS. PROMOTER HYPERMETHYLATION AFFECTING THE P16 GENE, RESULTING IN GENE SILENCING, HAS BEEN SHOWN TO OCCUR IN MANY HUMAN SOLID TUMOURS AND A 'HYPERMETHYLATION PROFILE' IN SOME LEUKAEMIAS HAS BEEN DEFINED. THE MOLECULAR MECHANISMS BY WHICH ABERRANT DNA METHYLATION TAKES PLACE DURING CARCINOGENESIS ARE STILL NOT CLEAR. HOWEVER, THE LARGE NUMBER OF TARGET GENES (INVOLVED IN TUMORIGENESIS) THAT ARE SILENCED BY ABERRANT METHYLATION SUGGESTS THAT INHIBITION OF THIS PROCESS MAY HAVE POTENTIAL AS CANCER THERAPY. DECITABINE (NSC-127716, DACOGEN; SUPERGEN) IS A POTENT AND SPECIFIC HYPOMETHYLATING AGENT AND AN INHIBITOR OF THE DNA METHYLTRANSFERASE ACTIVITY THAT MEDIATES DNA METHYLATION. DECITABINE HAS BEEN SHOWN TO HAVE A BROAD RANGE OF ANTINEOPLASTIC ACTIVITY IN PRECLINICAL STUDIES. THIS AGENT HAS EXHIBITED SIGNIFICANT ACTIVITY IN THE TREATMENT OF PATIENTS WITH MYELODYSPLASTIC SYNDROME, CHRONIC MYELOID LEUKAEMIA AND ACUTE MYELOID LEUKAEMIA, ALTHOUGH CLINICAL PHASE I AND II STUDIES WITH SOLID TUMOURS HAVE NOT BEEN VERY PROMISING. PHASE II AND III STUDIES ARE CURRENTLY ONGOING TO EVALUATE DECITABINE, BOTH ALONE AND IN COMBINATION, IN VARIOUS STAGES OF THESE HAEMATOLOGICAL MALIGNANCIES. 2003 10 5982 39 TET2 REGULATES IMMUNE TOLERANCE IN CHRONICALLY ACTIVATED MAST CELLS. MUTATION OF THE TET2 DNA-HYDROXYMETHYLASE HAS BEEN ASSOCIATED WITH A NUMBER OF IMMUNE PATHOLOGIES. THE DISPARITY IN PHENOTYPE AND CLINICAL PRESENTATION AMONG THESE PATHOLOGIES LEADS TO QUESTIONS REGARDING THE ROLE OF TET2 MUTATION IN PROMOTING DISEASE EVOLUTION IN DIFFERENT IMMUNE CELL TYPES. HERE WE SHOW THAT, IN PRIMARY MAST CELLS, TET2 EXPRESSION IS INDUCED IN RESPONSE TO CHRONIC AND ACUTE ACTIVATION SIGNALS. IN TET2-DEFICIENT MAST CELLS, CHRONIC ACTIVATION VIA THE ONCOGENIC KITD816V ALLELE ASSOCIATED WITH MASTOCYTOSIS, SELECTS FOR A SPECIFIC EPIGENETIC SIGNATURE CHARACTERIZED BY HYPERMETHYLATED DNA REGIONS (HMR) AT IMMUNE RESPONSE GENES. H3K27AC AND TRANSCRIPTION FACTOR BINDING IS CONSISTENT WITH PRIMING OR MORE OPEN CHROMATIN AT BOTH HMR AND NON-HMR IN PROXIMITY TO IMMUNE GENES IN THESE CELLS, AND THIS SIGNATURE COINCIDES WITH INCREASED PATHOLOGICAL INFLAMMATION SIGNALS. HMR ARE ALSO ASSOCIATED WITH A SUBSET OF IMMUNE GENES THAT ARE DIRECT TARGETS OF TET2 AND REPRESSED IN TET2-DEFICIENT CELLS. REPRESSION OF THESE GENES RESULTS IN IMMUNE TOLERANCE TO ACUTE STIMULATION THAT CAN BE RESCUED WITH VITAMIN C TREATMENT OR REITERATED WITH A TET INHIBITOR. OVERALL, OUR DATA SUPPORT A MODEL WHERE TET2 PLAYS A DIRECT ROLE IN PREVENTING IMMUNE TOLERANCE IN CHRONICALLY ACTIVATED MAST CELLS, SUPPORTING TET2 AS A VIABLE TARGET TO REPROGRAM THE INNATE IMMUNE RESPONSE FOR INNOVATIVE THERAPIES. 2022 11 6773 30 [ADVANCES OF RESEARCH ON DEMETHYLATION THERAPY FOR HEMATOLOGIC MALIGNANCIES]. DNA METHYLATION IS AN IMPORTANT AND REVERSIBLE EPIGENETIC MODIFICATION WHICH REGULATES GENOMIC STABILITY. METHYLATION IS ESSENTIAL FOR MAMMALIAN DEVELOPMENT. GENERALLY, GENE EXPRESSION LEVEL AND DNA METHYLATION ARE NEGATIVE CORRELATION. TRANSCRIPTIONAL SILENCING VIA METHYLATION OF CPG ISLANDS IN THE PROMOTER IS IMPORTANT FOR CELL GROWTH AND DIFFERENTIATION AND PLAYS A KEY ROLE IN TUMORIGENESIS. DEMETHYLATION DRUG CAN MODIFY CHROMATIN AND RESTORE THE ABILITY OF ANTI-ONCOGENE. DEMETHYLATION THERAPY AS A NEW THERAPY MAY TREAT EFFICIENTLY HEMATOLOGICAL MALIGNANCIES WITH RESISTANCE AND RELAPSE. IN THIS REVIEW, DNA METHYLATION MECHANISM, RELATIONSHIP BETWEEN ABERRANT METHYLATION AND HEMATOLOGIC MALIGNANCIES, MECHANISM OF DEMETHYLATION THERAPY, THE ADVANCE OF RESEARCH ON THE DEMETHYLATION THERAPY OF HEMATOLOGICAL MALIGNANCIES, SUCH AS ACUTE AND CHRONIC LEUKEMIA, LYMPHOMA, MYELODYSPLASTIC SYNDROME WERE SUMMARIZED. 2009 12 851 27 CHIP-SEQ ANALYSIS OF HUMAN CHRONIC MYELOID LEUKEMIA CELLS. MANY TRANSCRIPTION FACTORS, CHROMATIN-ASSOCIATED PROTEINS AND REGULATORY DNA ELEMENTS ARE GENETICALLY AND/OR EPIGENETICALLY ALTERED IN CANCER, INCLUDING CHRONIC MYELOID LEUKEMIA (CML). THIS LEADS TO DEREGULATION OF TRANSCRIPTION THAT IS OFTEN CAUSALLY LINKED TO THE TUMORIGENIC STATE. CHROMATIN-IMMUNOPRECIPITATION COUPLED WITH MASSIVELY PARALLEL DNA SEQUENCING (CHIP-SEQ) IS THE KEY TECHNOLOGY TO STUDY TRANSCRIPTION AS IT ALLOWS IN VIVO WHOLE-GENOME MAPPING OF EPIGENETIC MODIFICATIONS AND INTERACTIONS OF PROTEINS WITH DNA OR CHROMATIN. HOWEVER, NUMEROUS DNA/CHROMATIN-BINDING PROTEINS, INCLUDING EZH2, REMAIN DIFFICULT TO "CHIP," THUS YIELDING GENOME-WIDE BINDING MAPS OF ONLY SUBOPTIMAL QUALITY. HERE, WE DESCRIBE A CHIP-SEQ PROTOCOL OPTIMIZED FOR HIGH-QUALITY PROTEIN-GENOME BINDING MAPS THAT HAVE PROVEN ESPECIALLY USEFUL FOR STUDYING DIFFICULT TO 'CHIP' TRANSCRIPTION REGULATORY FACTORS IN CHRONIC MYELOID LEUKEMIA (CML) AND RELATED MALIGNANCIES. 2016 13 1336 24 DESCRIBING A TRANSCRIPTION FACTOR DEPENDENT REGULATION OF THE MICRORNA TRANSCRIPTOME. WHILE THE TRANSCRIPTION REGULATION OF PROTEIN CODING GENES WAS EXTENSIVELY STUDIED, LITTLE IS KNOWN ON HOW TRANSCRIPTION FACTORS ARE INVOLVED IN TRANSCRIPTION OF NON-CODING RNAS, SPECIFICALLY OF MICRORNAS. HERE, WE PROPOSE A STRATEGY TO STUDY THE POTENTIAL ROLE OF TRANSCRIPTION FACTOR IN REGULATING TRANSCRIPTION OF MICRORNAS USING PUBLICALLY AVAILABLE DATA, COMPUTATIONAL RESOURCES AND HIGH THROUGHPUT DATA. WE USE THE H3K4ME3 EPIGENETIC SIGNATURE TO IDENTIFY MICRORNA PROMOTERS AND CHROMATIN IMMUNOPRECIPITATION (CHIP)-SEQUENCING DATA FROM THE ENCODE PROJECT TO IDENTIFY MICRORNA PROMOTERS THAT ARE ENRICHED WITH TRANSCRIPTION FACTOR BINDING SITES. BY TRANSFECTING CELLS OF INTEREST WITH SHRNA TARGETING A TRANSCRIPTION FACTOR OF INTEREST AND SUBJECTING THE CELLS TO MICRORNA ARRAY, WE STUDY THE EFFECT OF THIS TRANSCRIPTION FACTOR ON THE MICRORNA TRANSCRIPTOME. AS AN ILLUSTRATIVE EXAMPLE WE USE OUR STUDY ON THE EFFECT OF STAT3 ON THE MICRORNA TRANSCRIPTOME OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS. 2016 14 5872 33 SUSTAINED TNF-ALPHA STIMULATION LEADS TO TRANSCRIPTIONAL MEMORY THAT GREATLY ENHANCES SIGNAL SENSITIVITY AND ROBUSTNESS. TRANSCRIPTIONAL MEMORY ALLOWS CERTAIN GENES TO RESPOND TO PREVIOUSLY EXPERIENCED SIGNALS MORE ROBUSTLY. HOWEVER, WHETHER AND HOW THE KEY PROINFLAMMATORY CYTOKINE TNF-ALPHA MEDIATES TRANSCRIPTIONAL MEMORY ARE POORLY UNDERSTOOD. USING HEK293F CELLS AS A MODEL SYSTEM, WE REPORT THAT SUSTAINED TNF-ALPHA STIMULATION INDUCES TRANSCRIPTIONAL MEMORY DEPENDENT ON TET ENZYMES. THE HYPOMETHYLATED STATUS OF TRANSCRIPTIONAL REGULATORY REGIONS CAN BE INHERITED, FACILITATING NF-KAPPAB BINDING AND MORE ROBUST SUBSEQUENT ACTIVATION. A HIGH INITIAL METHYLATION LEVEL AND CPG DENSITY AROUND KAPPAB SITES ARE CORRELATED WITH THE FUNCTIONAL POTENTIAL OF TRANSCRIPTIONAL MEMORY MODULES. INTERESTINGLY, THE CALCB GENE, ENCODING THE PROVEN MIGRAINE THERAPEUTIC TARGET CGRP, EXHIBITS THE BEST TRANSCRIPTIONAL MEMORY. A NEIGHBORING PRIMATE-SPECIFIC ENDOGENOUS RETROVIRUS STIMULATES MORE RAPID, MORE STRONG, AND AT LEAST 100-FOLD MORE SENSITIVE CALCB INDUCTION IN SUBSEQUENT TNF-ALPHA STIMULATION. OUR STUDY REVEALS THAT TNF-ALPHA-MEDIATED TRANSCRIPTIONAL MEMORY IS GOVERNED BY ACTIVE DNA DEMETHYLATION AND GREATLY SENSITIZES MEMORY GENES TO MUCH LOWER DOSES OF INFLAMMATORY CUES. 2020 15 1568 31 DNA METHYLATION OF TUMOR-SUPPRESSOR MIRNA GENES IN CHRONIC LYMPHOCYTIC LEUKEMIA. DNA METHYLATION IS ONE OF THE MOST IMPORTANT EPIGENETIC MODIFICATIONS OF THE GENOME INVOLVED IN THE REGULATION OF NUMEROUS CELLULAR PROCESSES THROUGH GENE SILENCING WITHOUT ALTERING DNA SEQUENCES. MIRNAS, A CLASS OF SINGLE-STRANDED NONCODING RNAS OF 19-25 NUCLEOTIDES IN LENGTH, FUNCTION AS POST-TRANSCRIPTIONAL REGULATORS OF GENE EXPRESSION LEADING TO MRNA CLEAVAGE OR TRANSLATIONAL REPRESSION OF THEIR CORRESPONDING TARGET PROTEIN-CODING GENES. RECENTLY, DYSREGULATION OF TUMOR SUPPRESSOR MIRNAS MEDIATED BY PROMOTER DNA HYPERMETHYLATION IS IMPLICATED IN HUMAN CANCERS, INCLUDING B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). MOREOVER, IT APPEARS THAT METHYLATED MIRNA GENES COULD BE POTENTIAL BIOMARKERS FOR CLL DIAGNOSIS OR THERAPY. THIS REVIEW WILL HIGHLIGHT THE ROLE OF ABERRANT METHYLATION OF MIRNA GENES IN THE PATHOGENESIS OF CLL. 2015 16 3791 37 INTERLEUKIN 6 SUPPORTS THE MAINTENANCE OF P53 TUMOR SUPPRESSOR GENE PROMOTER METHYLATION. A STRONG ASSOCIATION EXISTS BETWEEN STATES OF CHRONIC INFLAMMATION AND CANCER, AND IT IS BELIEVED THAT MEDIATORS OF INFLAMMATION MAY BE RESPONSIBLE FOR THIS PHENOMENON. INTERLEUKIN 6 (IL-6) IS AN INFLAMMATORY CYTOKINE KNOWN TO PLAY A ROLE IN THE GROWTH AND SURVIVAL OF MANY TYPES OF TUMORS, YET THE MECHANISMS EMPLOYED BY THIS PLEOMORPHIC CYTOKINE TO ACCOMPLISH THIS FEAT ARE STILL POORLY UNDERSTOOD. ANOTHER IMPORTANT FACTOR IN TUMOR DEVELOPMENT SEEMS TO BE THE HYPERMETHYLATION OF CPG ISLANDS LOCATED WITHIN THE PROMOTER REGIONS OF TUMOR SUPPRESSOR GENES. THIS COMMON EPIGENETIC ALTERATION ENABLES TUMOR CELLS TO REDUCE OR INACTIVATE THE EXPRESSION OF IMPORTANT TUMOR SUPPRESSOR AND CELL CYCLE REGULATORY GENES. HERE WE SHOW THAT IN THE IL-6-RESPONSIVE HUMAN MULTIPLE MYELOMA CELL LINE KAS 6/1, THE PROMOTER REGION OF P53 IS EPIGENETICALLY MODIFIED BY METHYLTRANSFERASES, RESULTING IN DECREASED LEVELS OF EXPRESSION. FURTHERMORE, CELLS TREATED WITH IL-6 EXHIBIT AN INCREASE IN THE EXPRESSION OF THE DNA MAINTENANCE METHYLATION ENZYME, DNMT-1. THE DNA METHYLTRANSFERASE INHIBITOR ZEBULARINE REVERSES THE METHYLATION OF THE P53 PROMOTER, ALLOWING THE RESUMPTION OF ITS EXPRESSION. HOWEVER, WHEN ZEBULARINE IS WITHDRAWN FROM THE CELLS, THE REESTABLISHMENT OF THE ORIGINAL CPG ISLAND METHYLATION WITHIN THE P53 PROMOTER DOES NOT OCCUR IN THE ABSENCE OF IL-6, AND CELLS WHICH DO NOT RECEIVE IL-6 EVENTUALLY DIE, AS P53 EXPRESSION CONTINUES UNCHECKED BY REMETHYLATION. INTERESTINGLY, THIS LOSS OF VIABILITY SEEMS TO INVOLVE NOT THE WITHDRAWAL OF CYTOKINE, BUT THE INABILITY OF THE CELL TO RESILENCE THE PROMOTER. CONSISTENT WITH THIS MODEL, WHEN CELLS THAT EXPRESS IL-6 IN AN AUTOCRINE FASHION ARE SUBJECTED TO IDENTICAL TREATMENT, P53 EXPRESSION IS REDUCED SHORTLY AFTER WITHDRAWAL OF ZEBULARINE. THEREFORE, IT SEEMS IL-6 IS CAPABLE OF MAINTAINING PROMOTER METHYLATION THUS REPRESENTING ONE OF THE POSSIBLE MECHANISMS USED BY INFLAMMATORY MEDIATORS IN THE GROWTH AND SURVIVAL OF TUMORS. 2005 17 2380 29 EPIGENETIC REGULATION OF WNT SIGNALING IN CHRONIC LYMPHOCYTIC LEUKEMIA. CERTAIN WNT AND WNT NETWORK TARGET GENES ARE EXPRESSED AT HIGHER OR LOWER LEVELS IN CHRONIC LYMPHOCYTIC LEUKEMIA COMPARED WITH NORMAL B-CELLS. THIS INCLUDES UPREGULATION OF NUCLEAR COMPLEX GENES, AS WELL AS GENES FOR CYTOPLASMIC PROTEINS AND WNT LIGANDS AND THEIR COGNATE RECEPTORS. IN ADDITION, EPIGENETIC SILENCING OF SEVERAL NEGATIVE REGULATORS OF THE WNT PATHWAY HAVE BEEN IDENTIFIED. THE BALANCE BETWEEN EPIGENETIC DOWNREGULATION OF NEGATIVE EFFECTOR GENES AND INCREASED EXPRESSION OF POSITIVE EFFECTOR GENES DEMONSTRATE THAT THE EPIGENETIC DOWNREGULATION OF WNT ANTAGONISTS IS ONE MECHANISM, PERHAPS THE MAIN MECHANISM, THAT IS PERMISSIVE TO ACTIVE WNT SIGNALING IN CHRONIC LYMPHOCYTIC LEUKEMIA. MOREOVER, CONSTITUTIVE ACTIVATION OF THE WNT NETWORK AND TARGET GENES IS LIKELY TO IMPACT ON ADDITIONAL INTERACTING SIGNALING PATHWAYS. BASED ON PUBLISHED STUDIES, WE PROPOSE A MODEL OF WNT SIGNALING THAT INVOLVES MAINLY PERMISSIVE EXPRESSION, AND SOMETIMES OVEREXPRESSION, OF POSITIVE EFFECTORS AND DOWNREGULATION OF NEGATIVE REGULATORS IN THE NETWORK. IN THIS MODEL, DNA METHYLATION, HISTONE MODIFICATIONS AND ALTERED EXPRESSION OF MICRORNA MOLECULES INTERACT TO ALLOW CONTINUOUS WNT SIGNALING. 2010 18 2111 30 EPIGENETIC FUNCTION OF TET FAMILY, 5-METHYLCYTOSINE, AND 5-HYDROXYMETHYLCYTOSINE IN HEMATOLOGIC MALIGNANCIES. DNA METHYLATION PLAYS SIGNIFICANT ROLES IN A VARIETY OF BIOLOGICAL AND PATHOLOGICAL PROCESSES INCLUDING MAMMALIAN DEVELOPMENT, GENOMIC IMPRINTING, RETROTRANSPOSON SILENCING, AND X-CHROMOSOME INACTIVATION. RECENT DISCOVERIES INDICATED THAT TEN-ELEVEN TRANSLOCATION (TET) FAMILY OF DIOXYGENASES CAN CONVERT 5-METHYLCYTOSINE (5-MC) INTO 5-HYDROXYMETHYLCYTOSINE (5-HMC). THE TET FAMILY INCLUDES THREE MEMBERS: TET1, TET2, AND TET3. WITH INCREASING EVIDENCE, MORE AND MORE BIOLOGICAL AND PATHOLOGICAL PROCESSES IN WHICH 5-HMC AND TET FAMILY SERVE UNPARALLELED BIOLOGICAL ROLES ARE NOTICED, FOR EXAMPLE, DNA DEMETHYLATION AND TRANSCRIPTIONAL REGULATION OF DIFFERENT TARGET GENES, WHICH ARE INVOLVED IN MANY HUMAN DISEASES, ESPECIALLY HEMATOLOGIC MALIGNANCIES, RESEMBLING CHRONIC MYELOMONOCYTIC LEUKEMIA, MYELODYSPLASTIC SYNDROMES, AND SO ON. IN THIS REVIEW, WE FOCUS ON THE DIVERSE FUNCTIONS OF TET FAMILY AND THE NOVEL EPIGENETIC MARKS, 5-MC AND 5-HMC, IN HEMATOLOGIC MALIGNANCIES. THIS REVIEW WILL PROVIDE VALUABLE INSIGHTS INTO THE POTENTIAL TARGETS OF HEMATOLOGIC MALIGNANCIES. FURTHER UNDERSTANDING OF THE NORMAL AND PATHOLOGICAL FUNCTIONS OF TET FAMILY MAY PROVIDE NEW METHODS TO DEVELOP NOVEL EPIGENETIC THERAPIES FOR TREATING HEMATOLOGIC MALIGNANCIES. 2019 19 1562 36 DNA METHYLATION OF ENHANCER ELEMENTS IN MYELOID NEOPLASMS: THINK OUTSIDE THE PROMOTERS? GENE REGULATION THROUGH DNA METHYLATION IS A WELL DESCRIBED PHENOMENON THAT HAS A PROMINENT ROLE IN PHYSIOLOGICAL AND PATHOLOGICAL CELL-STATES. THIS EPIGENETIC MODIFICATION IS USUALLY GROUPED IN REGIONS DENOMINATED CPG ISLANDS, WHICH FREQUENTLY CO-LOCALIZE WITH GENE PROMOTERS, SILENCING THE TRANSCRIPTION OF THOSE GENES. RECENT GENOME-WIDE DNA METHYLATION STUDIES HAVE CHALLENGED THIS PARADIGM, DEMONSTRATING THAT DNA METHYLATION OF REGULATORY REGIONS OUTSIDE PROMOTERS IS ABLE TO INFLUENCE CELL-TYPE SPECIFIC GENE EXPRESSION PROGRAMS UNDER PHYSIOLOGIC OR PATHOLOGIC CONDITIONS. COUPLING GENOME-WIDE DNA METHYLATION ASSAYS WITH HISTONE MARK ANNOTATION HAS ALLOWED FOR THE IDENTIFICATION OF SPECIFIC EPIGENOMIC CHANGES THAT AFFECT ENHANCER REGULATORY REGIONS, REVEALING AN ADDITIONAL LAYER OF COMPLEXITY TO THE EPIGENETIC REGULATION OF GENE EXPRESSION. IN THIS REVIEW, WE SUMMARIZE THE NOVEL EVIDENCE FOR THE MOLECULAR AND BIOLOGICAL REGULATION OF DNA METHYLATION IN ENHANCER REGIONS AND THE DYNAMISM OF THESE CHANGES CONTRIBUTING TO THE FINE-TUNING OF GENE EXPRESSION. WE ALSO ANALYZE THE CONTRIBUTION OF ENHANCER DNA METHYLATION ON THE EXPRESSION OF RELEVANT GENES IN ACUTE MYELOID LEUKEMIA AND CHRONIC MYELOPROLIFERATIVE NEOPLASMS. THE CHARACTERIZATION OF THE ABERRANT ENHANCER DNA METHYLATION PROVIDES NOT ONLY A NOVEL PATHOGENIC MECHANISM FOR DIFFERENT TUMORS BUT ALSO HIGHLIGHTS NOVEL POTENTIAL THERAPEUTIC TARGETS FOR MYELOID DERIVED NEOPLASMS. 2019 20 2025 29 EPIGENETIC CHANGES DURING DISEASE PROGRESSION IN A MURINE MODEL OF HUMAN CHRONIC LYMPHOCYTIC LEUKEMIA. EPIGENETIC ALTERATIONS, INCLUDING GAIN OR LOSS OF DNA METHYLATION, ARE A HALLMARK OF NEARLY EVERY MALIGNANCY. CHANGES IN DNA METHYLATION CAN IMPACT EXPRESSION OF CANCER-RELATED GENES INCLUDING APOPTOSIS REGULATORS AND TUMOR SUPPRESSORS. BECAUSE SUCH EPIGENETIC CHANGES ARE REVERSIBLE, THEY ARE BEING AGGRESSIVELY INVESTIGATED AS POTENTIAL THERAPEUTIC TARGETS. HERE WE USE THE EMU-TCL1 TRANSGENIC MOUSE MODEL OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) TO DETERMINE THE TIMING AND PATTERNS OF ABERRANT DNA METHYLATION, AND TO INVESTIGATE THE MECHANISMS THAT LEAD TO ABERRANT DNA METHYLATION. WE SHOW THAT CLL CELLS FROM EMU-TCL1 MICE AT VARIOUS STAGES RECAPITULATE EPIGENETIC ALTERATIONS SEEN IN HUMAN CLL. ABERRANT METHYLATION OF PROMOTER SEQUENCES IS OBSERVED AS EARLY AS 3 MONTHS OF AGE IN THESE ANIMALS, WELL BEFORE DISEASE ONSET. ABNORMALLY METHYLATED PROMOTER REGIONS INCLUDE BINDING SITES FOR THE TRANSCRIPTION FACTOR FOXD3. WE SHOW THAT LOSS OF FOXD3 EXPRESSION DUE TO AN NF-KAPPAB P50/P50:HDAC1 REPRESSOR COMPLEX OCCURS IN TCL1-POSITIVE B CELLS BEFORE METHYLATION. THEREFORE, SPECIFIC TRANSCRIPTIONAL REPRESSION IS AN EARLY EVENT LEADING TO EPIGENETIC SILENCING OF TARGET GENES IN MURINE AND HUMAN CLL. THESE RESULTS PROVIDE STRONG RATIONALE FOR THE DEVELOPMENT OF STRATEGIES TO TARGET NF-KAPPAB COMPONENTS IN CLL AND POTENTIALLY OTHER B-CELL MALIGNANCIES. 2009