1 188 177 ACETYL TRANSFERASE EP300 DEFICIENCY LEADS TO CHRONIC REPLICATION STRESS MEDIATED BY DEFECTIVE FORK PROTECTION AT STALLED REPLICATION FORKS. MUTATIONS IN THE EPIGENETIC REGULATOR AND GLOBAL TRANSCRIPTIONAL ACTIVATOR, E1A BINDING PROTEIN (EP300), IS BEING INCREASINGLY REPORTED IN AGGRESSIVE HEMATOLOGICAL MALIGNANCIES INCLUDING ADULT T-CELL LEUKEMIA/LYMPHOMA (ATLL). HOWEVER, THE MECHANISTIC CONTRIBUTION OF EP300 DYSREGULATION TO CANCER INITIATION AND PROGRESSION ARE CURRENTLY UNKNOWN. INDEPENDENT INHIBITION OF EP300 IN HUMAN CELLS RESULTS IN THE DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN REGULATING THE CELL CYCLE, DNA REPLICATION AND DNA DAMAGE RESPONSE. NEVERTHELESS, SPECIFIC FUNCTION PLAYED BY EP300 IN DNA REPLICATION INITIATION, PROGRESSION AND REPLICATION FORK INTEGRITY HAS NOT BEEN STUDIED. HERE, USING ATLL CELLS AS A MODEL TO STUDY EP300 DEFICIENCY AND AN P300-SELECTIVE PROTAC DEGRADER, DEGRADER AS A PHARMACOLOGIC TOOL, WE REVEAL THAT EP300-MUTATED CELLS DISPLAY PROLONGED CELL CYCLE KINETICS, DUE TO PRONOUNCED DYSREGULATIONS IN DNA REPLICATION DYNAMICS LEADING TO PERSISTENT GENOMIC INSTABILITY. ABERRANT DNA REPLICATION IN EP300-MUTATED CELLS IS CHARACTERIZED BY ELEVATED REPLICATION ORIGIN FIRING DUE TO INCREASED REPLISOME PAUSING GENOME-WIDE. WE DEMONSTRATE THAT EP300 DEFICIENCY RESULTS IN NUCLEOLYTIC DEGRADATION OF NASCENTLY SYNTHESIZED DNA AT STALLED FORKS DUE TO A PROMINENT DEFECT IN FORK STABILIZATION AND PROTECTION. THIS IN TURN RESULTS IN THE ACCUMULATION OF SINGLE STRANDED DNA GAPS AT COLLAPSED REPLICATION FORKS, IN EP300-DEFICIENT CELLS. INHIBITION OF MRE11 NUCLEASE RESCUES THE SSDNA ACCUMULATION INDICATING A DYSREGULATION IN DOWNSTREAM MECHANISMS THAT RESTRAIN NUCLEASE ACTIVITY AT STALLED FORKS. IMPORTANTLY, WE FIND THAT THE ABSENCE OF EP300 RESULTS IN DECREASED EXPRESSION OF BRCA2 PROTEIN EXPRESSION AND A DEPENDENCY ON POLD3-MEDIATED ERROR-PRONE REPLICATION RESTART MECHANISMS. THE OVERALL S-PHASE ABNORMALITIES OBSERVED LEAD TO UNDER-REPLICATED DNA IN G2/M THAT INSTIGATES MITOTIC DNA SYNTHESIS. THIS IN TURN IS ASSOCIATED WITH MITOTIC SEGREGATION DEFECTS CHARACTERIZED BY ELEVATED MICRONUCLEI FORMATION, ACCUMULATION OF CYTOSOLIC DNA AND TRANSMISSION OF UNREPAIRED INHERITED DNA LESIONS IN THE SUBSEQUENT G1-PHASE IN EP300-DEFICIENT CELLS. WE DEMONSTRATE THAT THE DNA REPLICATION DYNAMICS OF EP300-MUTATED CELLS ATLL CELLS RECAPITULATE FEATURES OF BRCA-DEFICIENT CANCERS. ALTOGETHER THESE RESULTS SUGGEST THAT MUTATIONS IN EP300 CAUSE CHRONIC DNA REPLICATION STRESS AND DEFECTIVE REPLICATION FORK RESTART RESULTS IN PERSISTENT GENOMIC INSTABILITY THAT UNDERLIE AGGRESSIVE CHEMO-RESISTANT TUMORIGENESIS IN HUMANS. 2023 2 3521 41 IKAROS: FROM CHROMATIN ORGANIZATION TO TRANSCRIPTIONAL ELONGATION CONTROL. IKAROS IS A MASTER REGULATOR OF CELL FATE DETERMINATION IN LYMPHOID AND OTHER HEMATOPOIETIC CELLS. THIS TRANSCRIPTION FACTOR ORCHESTRATES THE ASSOCIATION OF EPIGENETIC REGULATORS WITH CHROMATIN, ENSURING THE EXPRESSION PATTERN OF TARGET GENES IN A DEVELOPMENTAL AND LINEAGE-SPECIFIC MANNER. DISRUPTION OF IKAROS FUNCTION HAS BEEN ASSOCIATED WITH THE DEVELOPMENT OF ACUTE LYMPHOCYTIC LEUKEMIA, LYMPHOMA, CHRONIC MYELOID LEUKEMIA AND IMMUNE DISORDERS. PARADOXICALLY, WHILE IKAROS HAS BEEN SHOWN TO BE A TUMOR SUPPRESSOR, IT HAS ALSO BEEN IDENTIFIED AS A KEY THERAPEUTIC TARGET IN THE TREATMENT OF VARIOUS FORMS OF HEMATOLOGICAL MALIGNANCIES, INCLUDING MULTIPLE MYELOMA. INDEED, TARGETED PROTEOLYSIS OF IKAROS IS ASSOCIATED WITH DECREASED PROLIFERATION AND INCREASED DEATH OF MALIGNANT CELLS. ALTHOUGH THE MOLECULAR MECHANISMS HAVE NOT BEEN ELUCIDATED, THE EXPRESSION LEVELS OF IKAROS ARE VARIABLE DURING HEMATOPOIESIS AND COULD THEREFORE BE A KEY DETERMINANT IN EXPLAINING HOW ITS ABSENCE CAN HAVE SEEMINGLY OPPOSITE EFFECTS. MECHANISTICALLY, IKAROS COLLABORATES WITH A VARIETY OF PROTEINS AND COMPLEXES CONTROLLING CHROMATIN ORGANIZATION AT GENE REGULATORY REGIONS, INCLUDING THE NUCLEOSOME REMODELING AND DEACETYLASE COMPLEX, AND MAY FACILITATE TRANSCRIPTIONAL REPRESSION OR ACTIVATION OF SPECIFIC GENES. SEVERAL TRANSCRIPTIONAL REGULATORY FUNCTIONS OF IKAROS HAVE BEEN PROPOSED. AN EMERGING MECHANISM OF ACTION INVOLVES THE ABILITY OF IKAROS TO PROMOTE GENE REPRESSION OR ACTIVATION THROUGH ITS INTERACTION WITH THE RNA POLYMERASE II MACHINERY, WHICH INFLUENCES PAUSING AND PRODUCTIVE TRANSCRIPTION AT SPECIFIC GENES. THIS CONTROL APPEARS TO BE INFLUENCED BY IKAROS EXPRESSION LEVELS AND ISOFORM PRODUCTION. IN HERE, WE SUMMARIZE THE CURRENT STATE OF KNOWLEDGE ABOUT THE BIOLOGICAL ROLES AND MECHANISMS BY WHICH IKAROS REGULATES GENE EXPRESSION. WE HIGHLIGHT THE DYNAMIC REGULATION OF THIS FACTOR BY POST-TRANSLATIONAL MODIFICATIONS. FINALLY, POTENTIAL AVENUES TO EXPLAIN HOW IKAROS DESTRUCTION MAY BE FAVORABLE IN THE TREATMENT OF CERTAIN HEMATOLOGICAL MALIGNANCIES ARE ALSO EXPLORED. 2023 3 4506 34 MRTF-A MEDIATES LPS-INDUCED PRO-INFLAMMATORY TRANSCRIPTION BY INTERACTING WITH THE COMPASS COMPLEX. CHRONIC INFLAMMATION UNDERSCORES THE PATHOGENESIS OF A RANGE OF HUMAN DISEASES. LIPOPOLYSACCHARIDE (LPS) ELICITS STRONG PRO-INFLAMMATORY RESPONSES IN MACROPHAGES THROUGH THE TRANSCRIPTION FACTOR NF-KAPPAB. THE EPIGENETIC MECHANISM UNDERLYING LPS-INDUCED PRO-INFLAMMATORY TRANSCRIPTION IS NOT FULLY UNDERSTOOD. HEREIN, WE DESCRIBE A ROLE FOR MYOCARDIN-RELATED TRANSCRIPTION FACTOR A (MRTF-A, ALSO KNOWN AS MKL1) IN THIS PROCESS. MRTF-A OVEREXPRESSION ENHANCED NF-KAPPAB-DEPENDENT PRO-INFLAMMATORY TRANSCRIPTION, WHEREAS MRTF-A SILENCING INHIBITED THIS PROCESS. MRTF-A DEFICIENCY ALSO REDUCED THE SYNTHESIS OF PRO-INFLAMMATORY MEDIATORS IN A MOUSE MODEL OF COLITIS. LPS PROMOTED THE RECRUITMENT OF MRTF-A TO THE PROMOTERS OF PRO-INFLAMMATORY GENES IN AN NF-KAPPAB-DEPENDENT MANNER. RECIPROCALLY, MRTF-A INFLUENCED THE NUCLEAR ENRICHMENT AND TARGET BINDING OF NF-KAPPAB. MECHANISTICALLY, MRTF-A WAS NECESSARY FOR THE ACCUMULATION OF ACTIVE HISTONE MODIFICATIONS ON NF-KAPPAB TARGET PROMOTERS BY COMMUNICATING WITH THE HISTONE H3K4 METHYLTRANSFERASE COMPLEX (COMPASS). SILENCING OF INDIVIDUAL MEMBERS OF COMPASS, INCLUDING ASH2, WDR5 AND SET1 (ALSO KNOWN AS SETD1A), DOWNREGULATED THE PRODUCTION OF PRO-INFLAMMATORY MEDIATORS AND IMPAIRED THE NF-KAPPAB KINETICS. IN SUMMARY, OUR WORK HAS UNCOVERED A PREVIOUSLY UNKNOWN FUNCTION FOR MRTF-A AND PROVIDED INSIGHTS INTO THE RATIONALIZED DEVELOPMENT OF ANTI-INFLAMMATORY THERAPEUTIC STRATEGIES. 2014 4 2326 31 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY. 2018 5 5965 34 TEN-ELEVEN-TRANSLOCATION 2 (TET2) NEGATIVELY REGULATES HOMEOSTASIS AND DIFFERENTIATION OF HEMATOPOIETIC STEM CELLS IN MICE. THE TEN-ELEVEN-TRANSLOCATION 2 (TET2) GENE ENCODES A MEMBER OF TET FAMILY ENZYMES THAT ALTERS THE EPIGENETIC STATUS OF DNA BY OXIDIZING 5-METHYLCYTOSINE TO 5-HYDROXYMETHYLCYTOSINE (5HMC). SOMATIC LOSS-OF-FUNCTION MUTATIONS OF TET2 ARE FREQUENTLY OBSERVED IN PATIENTS WITH DIVERSE MYELOID MALIGNANCIES, INCLUDING MYELODYSPLASTIC SYNDROMES, MYELOPROLIFERATIVE NEOPLASMS, AND CHRONIC MYELOMONOCYTIC LEUKEMIA. BY ANALYZING MICE WITH TARGETED DISRUPTION OF THE TET2 CATALYTIC DOMAIN, WE SHOW HERE THAT TET2 IS A CRITICAL REGULATOR OF SELF-RENEWAL AND DIFFERENTIATION OF HEMATOPOIETIC STEM CELLS (HSCS). TET2 DEFICIENCY LED TO DECREASED GENOMIC LEVELS OF 5HMC AND AUGMENTED THE SIZE OF THE HEMATOPOIETIC STEM/PROGENITOR CELL POOL IN A CELL-AUTONOMOUS MANNER. IN COMPETITIVE TRANSPLANTATION ASSAYS, TET2-DEFICIENT HSCS WERE CAPABLE OF MULTILINEAGE RECONSTITUTION AND POSSESSED A COMPETITIVE ADVANTAGE OVER WILD-TYPE HSCS, RESULTING IN ENHANCED HEMATOPOIESIS INTO BOTH LYMPHOID AND MYELOID LINEAGES. IN VITRO, TET2 DEFICIENCY DELAYED HSC DIFFERENTIATION AND SKEWED DEVELOPMENT TOWARD THE MONOCYTE/MACROPHAGE LINEAGE. OUR DATA INDICATE THAT TET2 HAS A CRITICAL ROLE IN REGULATING THE EXPANSION AND FUNCTION OF HSCS, PRESUMABLY BY CONTROLLING 5HMC LEVELS AT GENES IMPORTANT FOR THE SELF-RENEWAL, PROLIFERATION, AND DIFFERENTIATION OF HSCS. 2011 6 787 27 CELLS OF ADULT T-CELL LEUKEMIA EVADE HTLV-1 TAX/NF-KAPPAB HYPERACTIVATION-INDUCED SENESCENCE. HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 (HTLV-1) IS THE ETIOLOGICAL AGENT OF ADULT T-CELL LEUKEMIA/LYMPHOMA (ATL). THE HTLV-1 VIRAL TRANS-ACTIVATOR/ONCOPROTEIN TAX IS A MAJOR DRIVER OF ATL, YET IT INDUCES RAPID P21(CIP1/WAF1) (P21)- AND P27(KIP1)-MEDIATED CELLULAR SENESCENCE THROUGH CONSTITUTIVE ACTIVATION (HYPERACTIVATION) OF NF-KAPPAB. ALTHOUGH CONSTITUTIVE NF-KAPPAB ACTIVATION IS A COMMON FEATURE OF T/B-CELL LEUKEMIA/LYMPHOMA, INCLUDING ATL, IT IS NOT KNOWN HOW ATL CELLS MAINTAIN CHRONIC NF-KAPPAB ACTIVATION WITHOUT UNDERGOING SENESCENCE. HERE, WE DEMONSTRATE THAT, IN CONTRAST TO HTLV-1(-) T-CELL LINES, ATL CELL LINES NO LONGER UNDERGO TAX-INDUCED SENESCENCE. ALTHOUGH TAX(+) AND TAX(-) ATL CELL LINES SHOWED SIGNATURES OF CONSTITUTIVE NF-KAPPAB ACTIVATION, THEIR ABILITY TO PROGRESS THROUGH THE CELL CYCLE WAS UNAFFECTED. IN SOME CASES, ATL CELL LINES CONTINUED TO PROLIFERATE DESPITE SIGNIFICANT UPREGULATION OF P21; ADDITIONALLY, MANY CELL LINES DISPLAYED ALTERED EXPRESSION OF G1 AND G1/S CYCLINS, PARTICULARLY OVEREXPRESSION OF CYCLIN D2. WE PROPOSE THAT, DURING THE COURSE OF ATL DEVELOPMENT, LEUKEMIA CELLS ACQUIRE GENETIC/EPIGENETIC CHANGES THAT CAN MITIGATE THE SENESCENCE RESPONSE TRIGGERED BY NF-KAPPAB HYPERACTIVATION. RESTORING THE NF-KAPPAB-INDUCED SENESCENCE RESPONSE WOULD LIKELY HELP TO CONTROL THE DEVELOPMENT AND PROGRESSION OF ATL AND SIMILAR LYMPHOID MALIGNANCIES. 2019 7 3877 35 KDM6A PROMOTES IMATINIB RESISTANCE THROUGH YY1-MEDIATED TRANSCRIPTIONAL UPREGULATION OF TRKA INDEPENDENTLY OF ITS DEMETHYLASE ACTIVITY IN CHRONIC MYELOGENOUS LEUKEMIA. RATIONALE: DESPITE LANDMARK THERAPY OF CHRONIC MYELOGENOUS LEUKEMIA (CML) WITH TYROSINE KINASE INHIBITORS (TKIS), DRUG RESISTANCE REMAINS PROBLEMATIC. CANCER PATHOGENESIS INVOLVES EPIGENETIC DYSREGULATION AND IN PARTICULAR, HISTONE LYSINE DEMETHYLASES (KDMS) HAVE BEEN IMPLICATED IN TKI RESISTANCE. WE SOUGHT TO IDENTIFY KDMS WITH ALTERED EXPRESSION IN CML AND DEFINE THEIR CONTRIBUTION TO IMATINIB RESISTANCE. METHODS: BIOINFORMATICS SCREENING COMPARED KDM EXPRESSION IN CML VERSUS NORMAL BONE MARROW WITH SHRNA KNOCKDOWN AND FLOW CYTOMETRY USED TO MEASURE EFFECTS ON IMATINIB-INDUCED APOPTOSIS IN K562 CELLS. TRANSCRIPTOMIC ANALYSES WERE PERFORMED AGAINST KDM6A CRISPR KNOCKOUT/SHRNA KNOCKDOWN K562 CELLS ALONG WITH GENE RESCUE EXPERIMENTS USING WILDTYPE AND MUTANT DEMETHYLASE-DEAD KDM6A CONSTRUCTS. CO-IMMUNOPRECIPITATION, LUCIFERASE REPORTER AND CHIP WERE EMPLOYED TO ELUCIDATE MECHANISMS OF KDM6A-DEPENDENT RESISTANCE. RESULTS: AMONGST FIVE KDMS UPREGULATED IN CML, ONLY KDM6A DEPLETION SENSITIZED CML CELLS TO IMATINIB-INDUCED APOPTOSIS. RE-INTRODUCTION OF DEMETHYLASE-DEAD KDM6A AS WELL AS WILD-TYPE KDM6A RESTORED IMATINIB RESISTANCE. RNA-SEQ IDENTIFIED NTRK1 GENE DOWNREGULATION AFTER DEPLETION OF KDM6A. MOREOVER, NTRK1 EXPRESSION POSITIVELY CORRELATED WITH KDM6A IN A SUBSET OF CLINICAL CML SAMPLES AND KDM6A KNOCKDOWN IN FRESH CML ISOLATES DECREASED NTRK1 ENCODED PROTEIN (TRKA) EXPRESSION. MECHANISTICALLY, KDM6A WAS RECRUITED TO THE NTRK1 PROMOTER BY THE TRANSCRIPTION FACTOR YY1 WITH SUBSEQUENT TRKA UPREGULATION ACTIVATING DOWN-STREAM SURVIVAL PATHWAYS TO INVOKE IMATINIB RESISTANCE. CONCLUSION: CONTRARY TO ITS REPORTED ROLE AS A TUMOR SUPPRESSOR AND INDEPENDENT OF ITS DEMETHYLASE FUNCTION, KDM6A PROMOTES IMATINIB-RESISTANCE IN CML CELLS. THE IDENTIFICATION OF THE KDM6A/YY1/TRKA AXIS AS A NOVEL IMATINIB-RESISTANCE MECHANISM REPRESENTS AN UNEXPLORED AVENUE TO OVERCOME TKI RESISTANCE IN CML. 2021 8 3470 36 HYPOXIA-INDUCIBLE KDM3A ADDICTION IN MULTIPLE MYELOMA. IN MULTIPLE MYELOMA (MM), THE BONE MARROW (BM) MICROENVIRONMENT MAY CONTAIN A MYELOMA CELL FRACTION THAT HAS ACQUIRED TREATMENT RESISTANCE BY UNDERGOING AN EPIGENETIC GENE EXPRESSION CHANGE. HYPOXIC STRESS IS AN IMPORTANT FACTOR IN THE BM MICROENVIRONMENT. RECENTLY, WE DEMONSTRATED THAT MIR-210 WAS UPREGULATED IN HYPOXIA AND DOWNREGULATED IRF4, WHICH IS KNOWN AS AN ESSENTIAL FACTOR IN MYELOMA ONCOGENESIS IN NORMOXIA. IN THE STUDY, WE DEMONSTRATED THAT MYELOMA CELLS STILL SHOWED A STRONG ANTIAPOPTOTIC PHENOTYPE DESPITE IRF4 DOWNREGULATION, SUGGESTING THAT ANOTHER ANTIAPOPTOTIC FACTOR MIGHT BE INVOLVED UNDER HYPOXIC STRESS. TO DETERMINE THE FACTOR OR FACTORS, WE CONDUCTED GENE EXPRESSION ANALYSIS ON MYELOMA CELLS (PRIMARY SAMPLES AND CELL LINES) THAT WERE EXPOSED TO CHRONIC HYPOXIA AND OBSERVED UPREGULATION OF GLYCOLYTIC GENES AND GENES ENCODING H3K9 DEMETHYLASES IN MYELOMA CELLS WITH HYPOXIA. AMONG THESE, KDM3A WAS MOST SIGNIFICANTLY UPREGULATED IN ALL EXAMINED CELLS, AND ITS KNOCKDOWN INDUCED APOPTOSIS OF MYELOMA CELLS IN CHRONIC HYPOXIA. EXPRESSION OF KDM3A WAS DEPENDENT ON HIF-1ALPHA, WHICH IS A TRANSCRIPTION FACTOR SPECIFICALLY UPREGULATED IN HYPOXIA. WE FURTHER DEMONSTRATED THAT AN ESSENTIAL TARGET OF KDM3A WAS A NONCODING GENE, MALAT1, WHOSE UPREGULATION CONTRIBUTED TO ACQUISITION OF AN ANTIAPOPTOTIC PHENOTYPE BY ACCUMULATION OF HIF-1ALPHA, LEADING TO UPREGULATION OF GLYCOLYTIC GENES UNDER HYPOXIA. THIS PROCESS WAS INDEPENDENT FROM IRF4. THESE RESULTS LED US TO CONCLUDE THAT THE HYPOXIA-INDUCIBLE HIF-1ALPHA-KDM3A-MALAT1 AXIS ALSO CONTRIBUTES TO ACQUISITION OF THE ANTIAPOPTOTIC PHENOTYPE VIA UPREGULATION OF GLYCOLYSIS-PROMOTING GENES. THUS, THIS AXIS IS A PROMISING THERAPEUTIC TARGET AGAINST MYELOMA CELLS IN THE BM MICROENVIRONMENT. 2018 9 3362 44 HISTONE LYSINE DEMETHYLASE KDM5B MAINTAINS CHRONIC MYELOID LEUKEMIA VIA MULTIPLE EPIGENETIC ACTIONS. THE HISTONE LYSINE DEMETHYLASE KDM5 FAMILY IS IMPLICATED IN NORMAL DEVELOPMENT AND STEM CELL MAINTENANCE BY EPIGENETIC MODULATION OF HISTONE METHYLATION STATUS. DEREGULATION OF THE KDM5 FAMILY HAS BEEN REPORTED IN VARIOUS TYPES OF CANCERS, INCLUDING HEMATOLOGICAL MALIGNANCIES. HOWEVER, THEIR TRANSCRIPTIONAL REGULATORY ROLES IN THE CONTEXT OF LEUKEMIA REMAIN UNCLEAR. HERE, WE FIND THAT KDM5B IS STRONGLY EXPRESSED IN NORMAL CD34(+) HEMATOPOIETIC STEM/PROGENITOR CELLS AND CHRONIC MYELOID LEUKEMIA (CML) CELLS. KNOCKDOWN OF KDM5B IN K562 CML CELLS REDUCED LEUKEMIA COLONY-FORMING POTENTIAL. TRANSCRIPTOME PROFILING OF KDM5B KNOCKDOWN K562 CELLS REVEALED THE DEREGULATION OF GENES INVOLVED IN MYELOID DIFFERENTIATION AND TOLL-LIKE RECEPTOR SIGNALING. THROUGH THE INTEGRATION OF TRANSCRIPTOME AND CHIP-SEQ PROFILING DATA, WE SHOW THAT KDM5B IS ENRICHED AT THE BINDING SITES OF THE GATA AND AP-1 TRANSCRIPTION FACTOR FAMILIES, SUGGESTING THEIR COLLABORATIONS IN THE REGULATION OF TRANSCRIPTION. EVEN THOUGH THE BINDING OF KDM5B SUBSTANTIALLY OVERLAPPED WITH H3K4ME1 OR H3K4ME3 MARK AT GENE PROMOTERS, ONLY A SMALL SUBSET OF THE KDM5B TARGETS SHOWED DIFFERENTIAL EXPRESSION IN ASSOCIATION WITH THE HISTONE DEMETHYLATION ACTIVITY. BY CHARACTERIZING THE INTERACTING PROTEINS IN K562 CELLS, WE DISCOVERED THAT KDM5B RECRUITS PROTEIN COMPLEXES INVOLVED IN THE MRNA PROCESSING MACHINERY, IMPLYING AN ALTERNATIVE EPIGENETIC ACTION MEDIATED BY KDM5B IN GENE REGULATION. OUR STUDY HIGHLIGHTS THE ONCOGENIC FUNCTIONS OF KDM5B IN CML CELLS AND SUGGESTS THAT KDM5B IS VITAL TO THE TRANSCRIPTIONAL REGULATION VIA MULTIPLE EPIGENETIC MECHANISMS. 2020 10 5823 30 STRESS INCREASES DNA METHYLATION OF THE NEURONAL PAS DOMAIN 4 (NPAS4) GENE. NEURONAL PER ARNT SIM DOMAIN 4 (NPAS4), A BRAIN-SPECIFIC HELIX-LOOP-HELIX TRANSCRIPTION FACTOR, WAS RECENTLY SHOWN TO REGULATE THE DEVELOPMENT OF GABAERGIC INHIBITORY NEURONS. NPAS4 MRNA EXPRESSION LEVELS WERE DECREASED IN THE HIPPOCAMPUS OF MICE EXPOSED TO STRESS, WHICH WAS ACCOMPANIED BY BRAIN DYSFUNCTION. WE HAVE SUGGESTED THAT TRANSIENT STRESS REDUCED NPAS4 TRANSCRIPTION THROUGH THE GLUCOCORTICOID RECEPTOR. IN THE PRESENT REPORT, WE INVESTIGATED THE POTENTIAL CONTRIBUTION OF EPIGENETIC MODIFICATIONS INDUCED BY STRESS ON NPAS4 GENE EXPRESSION. THE NPAS4 PROMOTER REGION CONTAINS TWO CPG ISLANDS; IN THE HIPPOCAMPUS, CHRONIC RESTRAINT STRESS INCREASES THE DNA METHYLATION LEVELS OF BOTH OF THESE CPG ISLANDS. IN THE NEURO2A CELL LINE, TREATMENT WITH A DNA METHYLTRANSFERASE INHIBITOR, 5-AZA-2'-DEOXYCYTIDINE, INCREASED NPAS4 MRNA LEVELS AND MARKEDLY REDUCED THE DNA METHYLATION LEVELS OF CPG ISLAND 2 IN THE NPAS4 PROMOTER. THE DNA METHYLATION SITES IN CPG ISLAND 2 OVERLAP WITH TWO CYCLIC ADENOSINE MONOPHOSPHATE RESPONSE ELEMENT (CRE) SEQUENCES. MUTATION OF THESE CRE SEQUENCES REDUCED NPAS4 PROMOTER ACTIVITY. THESE RESULTS SUGGEST THAT TRANSCRIPTION OF THE NPAS4 GENE IS DOWNREGULATED BY STRESS THROUGH DNA METHYLATION OF ITS PROMOTER. 2015 11 66 37 A KEY ROLE FOR EZH2 IN EPIGENETIC SILENCING OF HOX GENES IN MANTLE CELL LYMPHOMA. THE CHROMATIN MODIFIER EZH2 IS OVEREXPRESSED AND ASSOCIATED WITH INFERIOR OUTCOME IN MANTLE CELL LYMPHOMA (MCL). RECENTLY, WE DEMONSTRATED PREFERENTIAL DNA METHYLATION OF HOX GENES IN MCL COMPARED WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), DESPITE THESE GENES NOT BEING EXPRESSED IN EITHER ENTITY. SINCE EZH2 HAS BEEN SHOWN TO REGULATE HOX GENE EXPRESSION, TO GAIN FURTHER INSIGHT INTO ITS POSSIBLE ROLE IN DIFFERENTIAL SILENCING OF HOX GENES IN MCL VS. CLL, WE PERFORMED DETAILED EPIGENETIC CHARACTERIZATION USING REPRESENTATIVE CELL LINES AND PRIMARY SAMPLES. WE OBSERVED SIGNIFICANT OVEREXPRESSION OF EZH2 IN MCL VS. CLL. CHROMATIN IMMUNE PRECIPITATION (CHIP) ASSAYS REVEALED THAT EZH2 CATALYZED REPRESSIVE H3 LYSINE 27 TRIMETHYLATION (H3K27ME3), WHICH WAS SUFFICIENT TO SILENCE HOX GENES IN CLL, WHEREAS IN MCL H3K27ME3 IS ACCOMPANIED BY DNA METHYLATION FOR A MORE STABLE REPRESSION. MORE IMPORTANTLY, HYPERMETHYLATION OF THE HOX GENES IN MCL RESULTED FROM EZH2 OVEREXPRESSION AND SUBSEQUENT RECRUITMENT OF THE DNA METHYLATION MACHINERY ONTO HOX GENE PROMOTERS. THE IMPORTANCE OF EZH2 UPREGULATION IN THIS PROCESS WAS FURTHER UNDERSCORED BY SIRNA TRANSFECTION AND EZH2 INHIBITOR EXPERIMENTS. ALTOGETHER, THESE OBSERVATIONS IMPLICATE EZH2 IN THE LONG-TERM SILENCING OF HOX GENES IN MCL, AND ALLUDE TO ITS POTENTIAL AS A THERAPEUTIC TARGET WITH CLINICAL IMPACT. 2013 12 4361 45 MIR-96 ACTS AS A TUMOR SUPPRESSOR VIA TARGETING THE BCR-ABL1 ONCOGENE IN CHRONIC MYELOID LEUKEMIA BLASTIC TRANSFORMATION. MICRORNA-MEDIATED POSTTRANSCRIPTIONAL REGULATION IS AN IMPORTANT EPIGENETIC REGULATORY MECHANISM OF GENE EXPRESSION, AND ITS DYSREGULATION IS INVOLVED IN THE DEVELOPMENT AND PROGRESSION OF A VARIETY OF MALIGNANCIES, INCLUDING CHRONIC MYELOID LEUKEMIA (CML). THE BCR-ABL1 FUSION GENE IS NOT ONLY THE INITIATING FACTOR OF CML, BUT IT IS ALSO AN IMPORTANT DRIVING FACTOR FOR BLASTIC TRANSFORMATION. TYROSINE KINASE INHIBITORS (TKIS) TARGETING BCR-ABL1 TYROSINE KINASE ACTIVITY, REPRESENTED BY IMATINIB, ARE CURRENTLY THE FIRST-LINE TREATMENT FOR CML. HOWEVER, DUE TO PRIMARY RESISTANCE OR SECONDARY RESISTANCE CAUSED BY MUTATIONS IN THE BCR-ABL1 KINASE DOMAIN, TKIS CANNOT COMPLETELY PREVENT THE PROGRESSION OF CML; THUS, THE STUDY OF BCR-ABL1 GENE EXPRESSION REGULATION IS OF GREAT SIGNIFICANCE. IN THIS STUDY, BIOINFORMATICS ANALYSIS AND OUR RESULTS SHOWED THAT MIR-96 COULD DIRECTLY BIND TO THE 3'UTR REGION OF BCR-ABL1 TO REGULATE FUSION PROTEIN EXPRESSION, THEREBY REGULATING ITS DOWNSTREAM SIGNALING PATHWAY ACTIVITY. WE ALSO FOUND THAT MIR-96 WAS DOWNREGULATED DURING THE PROGRESSION FROM THE CHRONIC PHASE (CML-CP) TO THE BLAST CRISIS (CML-BC). DOWNREGULATION OF MIR-96 COULD PROMOTE THE PROLIFERATION AND PARTICIPATE IN THE CELL DIFFERENTIATION OF CML-BC CELLS. ADDITIONALLY, WE FOUND THAT THE NOVEL HISTONE DEACETYLASE DRUG CHIDAMIDE AND THE DNA METHYLTRANSFERASE INHIBITOR DECITABINE COULD RESTORE THE LOW EXPRESSION OF MIR-96 IN CML CELLS, AND THERE WERE TWO ABNORMAL HYPERMETHYLATED SITES IN THE PROMOTER REGION OF MIR-96 IN CML, SUGGESTING THAT ITS LOW EXPRESSION MIGHT BE AT LEAST PARTIALLY REGULATED BY EPIGENETIC MECHANISMS. IN ADDITION, RE-EXPRESSION OF MIR-96 COULD INCREASE THE SENSITIVITY OF CML-BC CELLS TO IMATINIB. THUS, MIR-96 FUNCTIONS AS A TUMOR SUPPRESSOR, AND RE-EXPRESSION OF THIS MICRORNA MIGHT HAVE THERAPEUTIC BENEFITS IN CML BLASTIC TRANSFORMATION. 2019 13 826 39 CHARACTERIZATION OF K562 CELLS: UNCOVERING NOVEL CHROMOSOMES, ASSESSING TRANSFERRIN RECEPTOR EXPRESSION, AND PROBING PHARMACOLOGICAL THERAPIES. HUMAN ERYTHROLEUKEMIC K562 CELLS REPRESENT THE PROTOTYPICAL CELL CULTURE MODEL OF CHRONIC MYELOID LEUKEMIA (CML). THE CELLS ARE PSEUDO-TRIPLOID AND POSITIVE FOR THE PHILADELPHIA CHROMOSOME. THEREFORE, K562 CELLS HAVE BEEN WIDELY USED FOR INVESTIGATING THE BCR/ABL1 ONCOGENE AND THE TYROSINE KINASE INHIBITOR, IMATINIB-MESYLATE. FURTHER, K562 CELLS OVEREXPRESS TRANSFERRIN RECEPTORS (TFR) AND HAVE BEEN USED AS A MODEL FOR TARGETING CYTOTOXIC THERAPIES, VIA RECEPTOR-MEDIATED ENDOCYTOSIS. HERE, WE HAVE CHARACTERIZED K562 CELLS FOCUSING ON THE KARYOTYPE OF CELLS IN PROLONGED CULTURE, REGULATION OF EXPRESSION OF TFR IN WILDTYPE (WT) AND DOXORUBICIN-RESISTANT CELLS, AND RESPONSES TO HISTONE DEACETYLASE INHIBITION (HDACI). KARYOTYPE ANALYSIS INDICATES NOVEL CHROMOSOMES AND GENE EXPRESSION ANALYSIS SUGGESTS A SHIFT OF CULTURED K562 CELLS AWAY FROM PATIENT-DERIVED LEUKEMIC CELLS. WE CONFIRM THE HIGH EXPRESSION OF TFR ON K562 CELLS USING IMMUNOFLUORESCENCE AND CELL-SURFACE RECEPTOR BINDING RADIOASSAYS. IMPORTANTLY, HIGH TFR EXPRESSION IS OBSERVED IN PATIENT-DERIVED CELLS, AND WE HIGHLIGHT THE PERSISTENT EXPRESSION OF TFR FOLLOWING DOXORUBICIN ACQUIRED RESISTANCE. EPIGENETIC ANALYSIS INDICATES THAT PERMISSIVE HISTONE ACETYLATION AND METHYLATION AT THE PROMOTER REGION REGULATES THE TRANSCRIPTION OF TFR IN K562 CELLS. FINALLY, WE SHOW RELATIVELY HIGH EXPRESSION OF HDAC ENZYMES IN K562 CELLS AND DEMONSTRATE THE CHEMOTOXIC EFFECTS OF HDACI, USING THE FDA-APPROVED HYDROXAMIC ACID, VORINOSTAT. TOGETHER WITH A DESCRIPTION OF MORPHOLOGY, INFRARED SPECTRAL ANALYSIS, AND EXAMINATION OF METABOLIC PROPERTIES, WE PROVIDE A COMPREHENSIVE CHARACTERIZATION OF K562 CELLS. OVERALL, K562 CELL CULTURE SYSTEMS REMAIN WIDELY USED FOR THE INVESTIGATION OF NOVEL THERAPEUTICS FOR CML, WHICH IS PARTICULARLY IMPORTANT IN CASES OF IMATINIB-MESYLATE RESISTANCE. 2023 14 598 30 BETA-ADRENERGIC SIGNALING PROMOTES TUMOR ANGIOGENESIS AND PROSTATE CANCER PROGRESSION THROUGH HDAC2-MEDIATED SUPPRESSION OF THROMBOSPONDIN-1. CHRONIC BEHAVIORAL STRESS AND BETA-ADRENERGIC SIGNALING HAVE BEEN SHOWN TO PROMOTE CANCER PROGRESSION, WHOSE UNDERLYING MECHANISMS ARE LARGELY UNCLEAR, ESPECIALLY THE INVOLVEMENT OF EPIGENETIC REGULATION. HISTONE DEACETYLASE-2 (HDAC2), AN EPIGENETIC REGULATOR, IS CRITICAL FOR STRESS-INDUCED CARDIAC HYPERTROPHY. IT IS UNKNOWN WHETHER IT IS NECESSARY FOR BETA-ADRENERGIC SIGNALING-PROMOTED CANCER PROGRESSION. USING XENOGRAFT MODELS, WE SHOWED THAT CHRONIC BEHAVIORAL STRESS AND BETA-ADRENERGIC SIGNALING PROMOTE ANGIOGENESIS AND PROSTATE CANCER PROGRESSION. HDAC2 WAS INDUCED BY BETA-ADRENERGIC SIGNALING IN VITRO AND IN MOUSE XENOGRAFTS. WE NEXT UNCOVERED THAT HDAC2 IS A DIRECT TARGET OF CAMP RESPONSE ELEMENT-BINDING PROTEIN (CREB) THAT IS ACTIVATED BY BETA-ADRENERGIC SIGNALING. NOTABLY, HDAC2 IS NECESSARY FOR BETA-ADRENERGIC SIGNALING TO INDUCE ANGIOGENESIS. WE FURTHER DEMONSTRATED THAT, UPON CREB ACTIVATION, HDAC2 REPRESSES THROMBOSPONDIN-1 (TSP1), A POTENT ANGIOGENESIS INHIBITOR, THROUGH EPIGENETIC REGULATION. TOGETHER, THESE DATA ESTABLISH A NOVEL PATHWAY THAT HDAC2 AND TSP1 ACT DOWNSTREAM OF CREB ACTIVATION IN BETA-ADRENERGIC SIGNALING TO PROMOTE CANCER PROGRESSION. 2017 15 5477 33 RESTORING THE FUNCTIONAL IMMUNOGENICITY OF CHRONIC LYMPHOCYTIC LEUKEMIA USING EPIGENETIC MODIFIERS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS A MALIGNANCY ARISING FROM IMMUNE CELLS (B-LYMPHOCYTES) ENDOWED WITH INTRINSIC ANTIGEN-PRESENTING CAPABILITIES. SUCH A FUNCTION HOWEVER IS LOST DURING MALIGNANT TRANSFORMATION AND CLL CELLS ARE WELL KNOWN FOR THEIR INABILITY TO PROCESS AND PRESENT ANTIGENS TO THE T-CELL ARM OF THE IMMUNE SYSTEM. INSTEAD, MALIGNANT CLL CELLS ELICIT A VAST ARRAY OF IMMUNE REGULATORY MECHANISMS CONDUCIVE TO T-CELL DYSFUNCTION AND IMMUNOSUPPRESSION. PREVIOUSLY, WE HAVE SHOWN THAT TREATMENT OF CLL CELLS WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE UNLEASHED TARGET ANTIGEN EXPRESSION. HERE WE SHOW FOR THE FIRST TIME THAT COMBINING TWO EPIGENETIC MODIFIERS, 5-AZA-2'-DEOXYCYTIDINE AND THE HISTONE DEACETYLASE INHIBITOR LAQ824 EFFECTIVELY RESTORES THE IMMUNOGENICITY OF CLL CELL LINES AS WELL AS PRIMARY CELLS OBTAINED FROM CLL PATIENTS. INDEED, SUCH A COMBINATION INDUCES THE EXPRESSION OF NOVEL AND HIGHLY ANTIGENIC CANCER-TESTIS ANTIGENS (CTAS) AND COSTIMULATORY MOLECULES. THESE CHANGES FACILITATE THE FORMATION OF ROBUST SUPRAMOLECULAR ACTIVATION COMPLEXES (SMAC) BETWEEN CLL CELLS AND RESPONDER T-CELLS LEADING TO INTRACELLULAR SIGNALING, LYTIC GRANULE MOBILIZATION, AND POLARIZATION OF FUNCTIONAL AND RELEVANT T-CELL RESPONSES. THIS CASCADE OF T-CELL ACTIVATING EVENTS TRIGGERED BY CLL CELLS WITH RESTORED APC FUNCTION, POINTS TO COMBINED EPIGENETIC MODIFIER TREATMENT AS A POTENTIAL IMMUNOTHERAPEUTIC STRATEGY FOR CLL PATIENTS. 2011 16 6069 38 THE DIOXIN RECEPTOR IS SILENCED BY PROMOTER HYPERMETHYLATION IN HUMAN ACUTE LYMPHOBLASTIC LEUKEMIA THROUGH INHIBITION OF SP1 BINDING. THE TRANSCRIPTION FACTOR ARYL HYDROCARBON RECEPTOR (AHR) HAS RELEVANT FUNCTIONS IN CELL PROLIFERATION. INTERESTINGLY, THE AHR CAN EITHER PROMOTE OR INHIBIT PROLIFERATION DEPENDING ON THE CELL PHENOTYPE. ALTHOUGH RECENT DATA REVEAL POTENTIAL PATHWAYS FOR AHR SIGNALING IN CELL PROLIFERATION, THE MECHANISMS THAT REGULATE ITS ACTIVITY IN TUMOR CELLS REMAIN UNKNOWN. HERE, WE HAVE ANALYZED PROMOTER HYPERMETHYLATION AS A POTENTIAL MECHANISM CONTROLLING AHR EXPRESSION IN HUMAN TUMOR CELLS. AHR PROMOTER CPG METHYLATION WAS SPORADIC IN A PANEL OF 19 TUMOR CELL LINES EXCEPT FOR THE CHRONIC MYELOID LEUKEMIA (CML) K562 AND THE ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) REH. WHEN COMPARED WITH NORMAL LYMPHOCYTES, REH HAD VERY LOW CONSTITUTIVE AHR EXPRESSION THAT COULD BE ATTRIBUTED TO PROMOTER HYPERMETHYLATION SINCE TREATMENT WITH THE DNA DEMETHYLATING AGENT 5-AZA-2'-DEOXYCITIDINE (AZA) SIGNIFICANTLY INCREASED AHR MRNA AND PROTEIN. THESE RESULTS IN LEUKEMIA-DERIVED CELL LINES WERE FURTHER CONFIRMED IN PRIMARY ALL, WHERE 33% OF THE PATIENTS (7/21) HAD AHR PROMOTER HYPERMETHYLATION. CHROMATIN IMMUNOPRECIPITATION (CHIP) SHOWED THAT METHYLATION IMPAIRED BINDING OF THE TRANSCRIPTION FACTOR SP1 TO THE AHR PROMOTER, THUS PROVIDING A MECHANISM FOR AHR DOWNREGULATION IN REH CELLS. THEREFORE, PROMOTER HYPERMETHYLATION REPRESENTS A NOVEL EPIGENETIC MECHANISM DOWNREGULATING AHR ACTIVITY IN HEMATOLOGICAL MALIGNANCIES SUCH AS ALL. 2006 17 4357 40 MIR-30E* IS OVEREXPRESSED IN PROSTATE CANCER AND PROMOTES NF-KAPPAB-MEDIATED PROLIFERATION AND TUMOR GROWTH. ACCORDING TO THE CDC PROSTATE CANCER (CAP) HAS THE HIGHEST INCIDENCE AND SECOND HIGHEST MORTALITY RATE AMONGST CANCERS IN AMERICAN MEN. CONSTITUTIVE NF-KAPPAB ACTIVATION IS A HALLMARK OF CAP AND THIS PATHWAY DRIVES MANY PRO-TUMORIGENIC CHARACTERISTICS OF CAP CELLS, INCLUDING CELL PROLIFERATION AND SURVIVAL. AN ACTIVATED NF-KAPPAB GENE SIGNATURE IS PREDICTIVE OF CAP PROGRESSION AND BIOCHEMICAL RECURRENCE FOLLOWING THERAPEUTIC INTERVENTION. HOWEVER, THE MECHANISMS THAT PERPETUATE NF-KAPPAB ACTIVATION ARE INCOMPLETELY UNDERSTOOD. GENES THAT CONTROL NF-KAPPAB ACTIVITY ARE RARELY MUTATED IN CAP SUGGESTING THAT EPIGENETIC MECHANISMS MAY CONTRIBUTE TO CONSTITUTIVE NF-KAPPAB ACTIVATION. MICRORNAS (MIRS) EPIGENETICALLY REGULATE MANY GENES INVOLVED WITH NF-KAPPAB ACTIVATION. IKAPPABALPHA IS A DIRECT INHIBITOR OF NF-KAPPAB; IT BINDS TO AND SEQUESTERS NF-KAPPAB IN THE CYTOPLASM RESULTING IN FUNCTIONAL INHIBITION. IKAPPABALPHA IS A TARGET GENE OF MIR-30E* YET THE EXPRESSION AND ONCOLOGICAL IMPACT OF MIR-30E* IN CAP IS UNKNOWN. WE REPORT THAT MIR-30E* EXPRESSION IS ELEVATED IN MULTIPLE MURINE MODELS OF CAP AND IS MOST PRONOUNCED IN LATE STAGE DISEASE. MIR-30E* DRIVES CAP PROLIFERATION AND TUMOR GROWTH THROUGH INHIBITION OF IKAPPABALPHA, WHICH RESULTS IN CHRONIC ACTIVATION OF NF-KAPPAB. ADDITIONALLY, WE SHOW THAT INHIBITION OF MIR-30E* IMPROVES CHEMOTHERAPEUTIC CONTROL OF CAP. THUS, MIR-30E* MAY PROVE TO BE A NOVEL CLINICAL TARGET WHOSE INHIBITION LEADS TO DECREASED CAP CELL PROLIFERATION AND SENSITIZATION OF CAP CELLS TO CHEMOTHERAPEUTICS. 2017 18 4303 30 MICRORNA-223 INHIBITS TISSUE FACTOR EXPRESSION IN VASCULAR ENDOTHELIAL CELLS. OBJECTIVE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY PROCESS, IN WHICH VASCULAR ENDOTHELIAL CELLS (ECS) BECOME DYSFUNCTIONAL OWING TO THE EFFECTS OF CHEMICAL SUBSTANCES, SUCH AS INFLAMMATORY FACTOR AND GROWTH FACTORS. TISSUE FACTOR (TF) EXPRESSION IS INDUCED BY THE ABOVE CHEMICAL SUBSTANCES IN ACTIVATED ECS. TF INITIATES THROMBOSIS ON DISRUPTED ATHEROSCLEROTIC PLAQUES WHICH PLAYS AN ESSENTIAL ROLE DURING THE ONSET OF ACUTE CORONARY SYNDROMES (ACS). INCREASING EVIDENCES SUGGEST THE IMPORTANT ROLE OF MICRORNAS AS EPIGENETIC REGULATORS OF ATHEROSCLEROTIC DISEASE. THE AIM OF OUR STUDY IS TO IDENTIFY IF MICRORNA-223 (MIR-223) TARGETS TF IN ECS. METHODS AND RESULTS: BIOINFORMATIC ANALYSIS SHOWED THAT TF IS A TARGET CANDIDATE OF MIR-223. WESTERN BLOTTING ANALYSIS REVEALED THAT TUMOR NECROSIS FACTOR ALPHA (TNF-ALPHA) INCREASED TF EXPRESSION IN AORTA OF C57BL/6J MICE AND CULTURED ECS (EA.HY926 CELLS AND HUVEC) AFTER 4 H TREATMENT. IN TNF-ALPHA TREATED ECS, TF MRNA WAS ALSO INCREASED MEASURED BY REAL-TIME PCR. REAL-TIME PCR RESULTS SHOWED THAT MIR-223 LEVELS WERE DOWNREGULATED IN TNF-ALPHA-TREATED AORTA OF C57BL/6J MICE AND CULTURED ECS. TRANSFECTION OF ECS WITH MIR-223 MIMIC OR MIR-223 INHIBITOR MODIFIED TF EXPRESSION BOTH IN MRNA AND PROTEIN LEVELS. LUCIFERASE ASSAYS CONFIRMED THAT MIR-223 SUPPRESSED TF EXPRESSION BY BINDING TO THE SEQUENCE OF TF 3'-UNTRANSLATED REGIONS (3'UTR). TF PROCOAGULANT ACTIVITY WAS INHIBITED BY OVEREXPRESSING MIR-223 WITH OR WITHOUT TNF-ALPHA STIMULATION. CONCLUSIONS: MIR-223-MEDIATED SUPPRESSION OF TF EXPRESSION PROVIDES A NOVEL MOLECULAR MECHANISM FOR THE REGULATION OF COAGULATION CASCADE, AND SUGGESTS A CLUE AGAINST THROMBOGENESIS DURING THE PROCESS OF ATHEROSCLEROTIC PLAQUE RUPTURE. 2014 19 329 36 ALPHA-OXOGLUTARATE INHIBITS THE PROLIFERATION OF IMMORTALIZED NORMAL BLADDER EPITHELIAL CELLS VIA AN EPIGENETIC SWITCH INVOLVING ARID1A. INTERSTITIAL CYSTITIS (IC) IS A CHRONIC URINARY TRACT DISEASE THAT IS CHARACTERIZED BY UNPLEASANT SENSATIONS, SUCH AS PERSISTENT PELVIC PAIN, IN THE ABSENCE OF INFECTION OR OTHER IDENTIFIABLE CAUSES. WE PREVIOUSLY PERFORMED COMPREHENSIVE METABOLOMICS PROFILING OF URINE SAMPLES FROM IC PATIENTS USING NUCLEAR MAGNETIC RESONANCE AND GAS-CHROMATOGRAPHY/MASS SPECTROMETRY AND FOUND THAT URINARY ALPHA-OXOGLUTARATE (ALPHA-OG), WAS SIGNIFICANTLY ELEVATED. ALPHA-OG, A TRICARBOXYLIC ACID (TCA) CYCLE INTERMEDIATE, REPORTEDLY FUNCTIONS TO SUPPRESS THE PROLIFERATION OF IMMORTALIZED NORMAL HUMAN BLADDER EPITHELIAL CELLS. HERE, WE IDENTIFIED AT-RICH INTERACTIVE DOMAIN 1 A (ARID1A), A KEY CHROMATIN REMODELER, AS BEING HYPOMETHYLATED AND UPREGULATED BY ALPHA-OG TREATMENT. THIS WAS DONE THROUGH EPIC DNA METHYLATION PROFILING AND SUBSEQUENT BIOCHEMICAL APPROACHES, INCLUDING QUANTITATIVE RT-PCR AND WESTERN BLOT ANALYSES. FURTHERMORE, WE FOUND THAT ALPHA-OG ALMOST COMPLETELY SUPPRESSES TEN-ELEVEN TRANSLOCATION (TET) ACTIVITY, BUT DOES NOT AFFECT DNA METHYLTRANSFERASE (DNMT) ACTIVITY. ALTOGETHER, OUR STUDIES REVEAL THE POTENTIAL ROLE OF ALPHA-OG IN EPIGENETIC REMODELING THROUGH ITS EFFECTS ON ARID1A AND TET EXPRESSION IN THE BLADDER. THIS MAY PROVIDE A NEW POSSIBLE THERAPEUTIC STRATEGY IN TREATING IC. 2018 20 6590 40 TUMOR SUPPRESSOR INACTIVATION IN THE PATHOGENESIS OF ADULT T-CELL LEUKEMIA. TUMOR SUPPRESSOR FUNCTIONS ARE ESSENTIAL TO CONTROL CELLULAR PROLIFERATION, TO ACTIVATE THE APOPTOSIS OR SENESCENCE PATHWAY TO ELIMINATE UNWANTED CELLS, TO LINK DNA DAMAGE SIGNALS TO CELL CYCLE ARREST CHECKPOINTS, TO ACTIVATE APPROPRIATE DNA REPAIR PATHWAYS, AND TO PREVENT THE LOSS OF ADHESION TO INHIBIT INITIATION OF METASTASES. THEREFORE, TUMOR SUPPRESSOR GENES ARE INDISPENSABLE TO MAINTAINING GENETIC AND GENOMIC INTEGRITY. CONSEQUENTLY, INACTIVATION OF TUMOR SUPPRESSORS BY SOMATIC MUTATIONS OR EPIGENETIC MECHANISMS IS FREQUENTLY ASSOCIATED WITH TUMOR INITIATION AND DEVELOPMENT. IN CONTRAST, REACTIVATION OF TUMOR SUPPRESSOR FUNCTIONS CAN EFFECTIVELY REVERSE THE TRANSFORMED PHENOTYPE AND LEAD TO CELL CYCLE ARREST OR DEATH OF CANCEROUS CELLS AND BE USED AS A THERAPEUTIC STRATEGY. ADULT T-CELL LEUKEMIA/LYMPHOMA (ATLL) IS AN AGGRESSIVE LYMPHOPROLIFERATIVE DISEASE ASSOCIATED WITH INFECTION OF CD4 T CELLS BY THE HUMAN T-CELL LEUKEMIA VIRUS TYPE 1 (HTLV-I). HTLV-I-ASSOCIATED T-CELL TRANSFORMATION IS THE RESULT OF A MULTISTEP ONCOGENIC PROCESS IN WHICH THE VIRUS INITIALLY INDUCES CHRONIC T-CELL PROLIFERATION AND ALTERS CELLULAR PATHWAYS RESULTING IN THE ACCUMULATION OF GENETIC DEFECTS AND THE DEREGULATED GROWTH OF VIRALLY INFECTED CELLS. THIS REVIEW WILL FOCUS ON THE CURRENT KNOWLEDGE OF THE GENETIC AND EPIGENETIC MECHANISMS REGULATING THE INACTIVATION OF TUMOR SUPPRESSORS IN THE PATHOGENESIS OF HTLV-I. 2015