1 5695 124 SILENCING UHRF1 ENHANCES CELL AUTOPHAGY TO PREVENT ARTICULAR CHONDROCYTES FROM APOPTOSIS IN OSTEOARTHRITIS THROUGH PI3K/AKT/MTOR SIGNALING PATHWAY. OSTEOARTHRITIS (OA) IS A COMMON CHRONIC DEGENERATIVE JOINT DISEASE, AND CHONDROCYTE APOPTOSIS IS ONE OF MOST IMPORTANT PATHOLOGICAL CHANGES OF OA PATHOGENESIS. GROWING STUDIES HAVE SHOWN THAT UBIQUITIN-LIKE WITH PHD AND RING FINGER DOMAINS 1 (UHRF1) IS AN IMPORTANT EPIGENETIC REGULATORY FACTOR THAT REGULATES CELL PROLIFERATION AND APOPTOSIS OF VARIOUS TUMORS, BUT ITS ROLE IN OA REMAINS ILL-DEFINED. IN THE PRESENT STUDY, WE FOUND THAT UHRF1 EXPRESSION WAS INCREASED IN HUMAN OA CARTILAGE TISSUES, COMPARED WITH NORMAL CARTILAGE TISSUES. INTERLEUKIN-1BETA (IL-1BETA), A MAJOR INFLAMMATORY CYTOKINE THAT PROMOTES CARTILAGE DEGRADATION IN OA, WAS USED TO STIMULATE PRIMARY HUMAN CHONDROCYTES IN VITRO. THE EXPRESSION OF UHRF1 WAS ALSO ENHANCED IN IL-1BETA-INDUCED CHONDROCYTES. MOREOVER, DOWN-REGULATION OF UHRF1 INDUCED AN INCREASE ON CELL PROLIFERATION AND AUTOPHAGY, AND A DECREASE ON APOPTOSIS OF CHONDROCYTES AFTER IL-1BETA TREATMENT. FURTHER DATA INDICATED THAT SILENCING UHRF1 ATTENUATED THE UP-REGULATION OF IL-1BETA ON PHOSPHOINOSITIDE 3-KINASE (PI3K)/PROTEIN KINASE B (AKT)/MAMMALIAN TARGET OF RAPAMYCIN (MTOR) SIGNALING PATHWAY IN CHONDROCYTES. THEN, AN ACTIVATOR OF PI3K WEAKENED THE EFFECT OF UHRF1 SILENCING ON CELL PROLIFERATION, AUTOPHAGY, APOPTOSIS OF IL-1BETA-INDUCED CHONDROCYTES, AND THE CELL AUTOPHAGY SPECIAL INHIBITOR 3-METHYLADENINE (3-MA) ALSO SHOWED A SAME IMPACT ON UHRF1, HENCE SUGGESTING THAT KNOCKDOWN OF UHRF1 ENHANCES CELL AUTOPHAGY TO PROTECT CHONDROCYTES FROM APOPTOSIS IN OA THROUGH PI3K/AKT/MTOR SIGNALING PATHWAY. IN CONCLUSION, OUR STUDY SUGGESTS THAT UHRF1 MAY BE A POTENTIAL REGULATOR OF CHONDROCYTE APOPTOSIS IN THE PATHOGENESIS OF OA. 2020 2 3175 35 H2AX PHOSPHORYLATION REGULATED BY P38 IS INVOLVED IN BIM EXPRESSION AND APOPTOSIS IN CHRONIC MYELOGENOUS LEUKEMIA CELLS INDUCED BY IMATINIB. INCREASING EVIDENCE SUGGESTS THAT HISTONE H2AX PLAYS A CRITICAL ROLE IN REGULATION OF TUMOR CELL APOPTOSIS AND ACTS AS A NOVEL HUMAN TUMOR SUPPRESSOR PROTEIN. HOWEVER, THE ACTION OF H2AX IN CHRONIC MYELOGENOUS LEUKEMIA (CML) CELLS IS UNKNOWN. THE DETAILED MECHANISM AND EPIGENETIC REGULATION BY H2AX REMAIN ELUSIVE IN CANCER CELLS. HERE, WE REPORT THAT H2AX WAS INVOLVED IN APOPTOSIS OF CML CELLS. OVEREXPRESSION OF H2AX INCREASED APOPTOTIC SENSITIVITY OF CML CELLS (K562) INDUCED BY IMATINIB. HOWEVER, OVEREXPRESSION OF SER139-MUTATED H2AX (BLOCKING PHOSPHORYLATION) DECREASED SENSITIVITY OF K562 CELLS TO APOPTOSIS. SIMILARLY, KNOCKDOWN OF H2AX MADE K562 CELLS RESISTANT TO APOPTOTIC INDUCTION. THESE RESULTS REVEALED THAT THE FUNCTION OF H2AX INVOLVED IN APOPTOSIS IS STRICTLY RELATED TO ITS PHOSPHORYLATION (SER139). OUR DATA FURTHER INDICATED THAT IMATINIB MAY STIMULATE MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) FAMILY MEMBER P38, AND H2AX PHOSPHORYLATION FOLLOWED A SIMILAR TIME COURSE, SUGGESTING A PARALLEL RESPONSE. H2AX PHOSPHORYLATION CAN BE BLOCKED BY P38 SIRNA OR ITS INHIBITOR. THESE DATA DEMONSTRATED THAT H2AX PHOSPHORYLATION WAS REGULATED BY P38 MAPK PATHWAY IN K562 CELLS. HOWEVER, THE P38 MAPK DOWNSTREAM, MITOGEN- AND STRESS-ACTIVATED PROTEIN KINASE-1 AND -2, WHICH PHOSPHORYLATED HISTONE H3, WERE NOT REQUIRED FOR H2AX PHOSPHORYLATION DURING APOPTOSIS. FINALLY, WE PROVIDED EPIGENETIC EVIDENCE THAT H2AX PHOSPHORYLATION REGULATED APOPTOSIS-RELATED GENE BIM EXPRESSION. BLOCKING OF H2AX PHOSPHORYLATION INHIBITED BIM GENE EXPRESSION. TAKEN TOGETHER, THESE DATA DEMONSTRATED THAT H2AX PHOSPHORYLATION REGULATED BY P38 IS INVOLVED IN BIM EXPRESSION AND APOPTOSIS IN CML CELLS INDUCED BY IMATINIB. 2014 3 5917 27 TARGETING BCL-2 IN B-CELL MALIGNANCIES AND OVERCOMING THERAPEUTIC RESISTANCE. DEFECTS IN APOPTOSIS CAN PROMOTE TUMORIGENESIS AND IMPAIR RESPONSES OF MALIGNANT B CELLS TO CHEMOTHERAPEUTICS. MEMBERS OF THE B-CELL LEUKEMIA/LYMPHOMA-2 (BCL-2) FAMILY OF PROTEINS ARE KEY REGULATORS OF THE INTRINSIC, MITOCHONDRIAL APOPTOTIC PATHWAY. OVEREXPRESSION OF ANTIAPOPTOTIC BCL-2 FAMILY PROTEINS IS ASSOCIATED WITH TREATMENT RESISTANCE AND POOR PROGNOSIS. THUS, INHIBITION OF BCL-2 FAMILY PROTEINS IS A RATIONAL THERAPEUTIC OPTION FOR MALIGNANCIES THAT ARE DEPENDENT ON ANTIAPOPTOTIC BCL-2 FAMILY PROTEINS. VENETOCLAX (ABT-199, GDC-0199) IS A HIGHLY SELECTIVE BCL-2 INHIBITOR THAT REPRESENTS THE FIRST APPROVED AGENT OF THIS CLASS AND IS CURRENTLY WIDELY USED IN THE TREATMENT OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AS WELL AS ACUTE MYELOID LEUKEMIA (AML). DESPITE IMPRESSIVE CLINICAL ACTIVITY, VENETOCLAX MONOTHERAPY FOR A PROLONGED DURATION CAN LEAD TO DRUG RESISTANCE OR LOSS OF DEPENDENCE ON THE TARGETED PROTEIN. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF THE MECHANISM OF ACTION OF BCL-2 INHIBITION AND THE ROLE OF THIS APPROACH IN THE CURRENT TREATMENT PARADIGM OF B-CELL MALIGNANCIES. WE SUMMARIZE THE DRIVERS OF DE NOVO AND ACQUIRED RESISTANCE TO VENETOCLAX THAT ARE CLOSELY ASSOCIATED WITH COMPLEX CLONAL SHIFTS, INTERPLAY OF EXPRESSION AND INTERACTIONS OF BCL-2 FAMILY MEMBERS, TRANSCRIPTIONAL REGULATORS, AND METABOLIC MODULATORS. WE ALSO EXAMINE HOW TUMORS INITIALLY RESISTANT TO VENETOCLAX BECOME RESPONSIVE TO IT FOLLOWING PRIOR THERAPIES. HERE, WE SUMMARIZE PRECLINICAL DATA PROVIDING A RATIONALE FOR EFFICACIOUS COMBINATION STRATEGIES OF VENETOCLAX TO OVERCOME THERAPEUTIC RESISTANCE BY A TARGETED APPROACH DIRECTED AGAINST ALTERNATIVE ANTIAPOPTOTIC BCL-2 FAMILY PROTEINS (MCL-1, BCL-XL), COMPENSATORY PROSURVIVAL PATHWAYS, EPIGENETIC MODIFIERS, AND DYSREGULATED CELLULAR METABOLISM/ENERGETICS FOR DURABLE CLINICAL REMISSIONS. 2020 4 1287 25 DECITABINE-INDUCED APOPTOSIS IS DERIVED BY PUMA AND NOXA INDUCTION IN CHRONIC MYELOID LEUKEMIA CELL LINE AS WELL AS IN PBL AND IS POTENTIATED BY SAHA. RESTORATION OF CELLULAR APOPTOTIC PATHWAYS PLAYS A CRUCIAL ROLE IN CANCER THERAPY STRATEGIES. IN A BROAD SPECTRUM OF ANTICANCER DRUGS, EPIGENETIC EFFECTORS ARE IN THE CENTER OF INTEREST MOSTLY BECAUSE OF POTENTIAL REVERSIBILITY OF THEIR ACTION. METHYLATION STATUS OF THE CELLS IS INFLUENCED BY METHYLTRANSFERASE INHIBITOR 2-DEOXY-5'-AZACYTIDINE (DECITABINE, DAC), BUT HIGHER CONCENTRATIONS OF THIS AGENT CAUSE A DNA-DAMAGE. IN OUR STUDY, TUMOR SUPRESSOR P53-APOPTOTIC PATHWAY WAS ACTIVATED IN DECITABINE-INDUCED CELL DEATH. EXPRESSION OF P53-INDUCIBLE BH3-ONLY APOPTOTIC PROTEINS PUMA AND NOXA WAS ELEVATED AND LARGE ACTIVATION OF EXECUTIVE CASPASES WAS OBSERVED. THE EXTENT OF ACETYLATION IN THE CELL IS AFFECTED BY HISTONEDEACETYLASE INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA). COMBINATION OF SAHA WITH DECITABINE BROUGHT SYNERGISTIC EFFECT ON APOPTOSIS TRIGGERING IN CML-T1 CELL LINE, BUT APOPTOSIS AS WELL AS NECROSIS OCCURRED ALSO IN NORMAL PERIPHERAL BLOOD LYMPHOCYTES. THEREFORE, PROMISING POTENTIAL OF SUCH COMBINED THERAPY CALLS FOR MORE DETAILED INVESTIGATION OF UNWANTED EFFECTS IN NORMAL CELLS. 2011 5 3725 36 INHIBITION OF GLYCOGEN SYNTHASE KINASE-3 ACTIVITY LEADS TO EPIGENETIC SILENCING OF NUCLEAR FACTOR KAPPAB TARGET GENES AND INDUCTION OF APOPTOSIS IN CHRONIC LYMPHOCYTIC LEUKEMIA B CELLS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS COMMONLY DEFINED AS A DISEASE OF FAILED APOPTOSIS OF B CELLS AND REMAINS AN INCURABLE DISEASE. THE MECHANISM OF RESISTANCE TO APOPTOSIS IN CLL IS COMPLEX AND INFLUENCED BY NUMEROUS FACTORS, INCLUDING NUCLEAR FACTOR KAPPAB (NFKAPPAB)-MEDIATED EXPRESSION OF ANTIAPOPTOTIC MOLECULES. RECENT EVIDENCE INDICATES THAT GLYCOGEN SYNTHASE KINASE-3BETA (GSK-3BETA) POSITIVELY REGULATES NFKAPPAB-MEDIATED GENE TRANSCRIPTION AND CELL SURVIVAL. USING MALIGNANT B CELLS COLLECTED FROM PATIENTS WITH CLL, WE FIND THAT BOTH GSK-3BETA AND NFKAPPAB ACCUMULATE IN THE NUCLEUS OF CLL B CELLS, AND PHARMACOLOGIC INHIBITION OF GSK-3 RESULTS IN DECREASED EXPRESSION OF TWO NFKAPPAB TARGET GENES BCL-2 AND XIAP AND A SUBSEQUENT INCREASE IN CLL B-CELL APOPTOSIS EX VIVO. FURTHERMORE, WE OBSERVED THAT INHIBITION OF GSK-3 LEADS TO A DECREASE IN NFKAPPAB-MEDIATED GENE TRANSCRIPTION BUT DOES NOT AFFECT THE NUCLEAR ACCUMULATION OF NFKAPPAB IN CLL B CELLS. LAST, USING CHROMATIN IMMUNOPRECIPITATION, WE SHOW THAT GSK-3 INHIBITION ABROGATES NFKAPPAB BINDING TO ITS TARGET GENE PROMOTERS (XIAP, BCL-2), IN PART THROUGH EPIGENETIC MODIFICATION OF HISTONES. OUR RESULTS ESTABLISH THAT INHIBITION OF GSK-3 ABROGATES NFKAPPAB BINDING TO ITS TARGET GENE PROMOTERS THROUGH AN EPIGENETIC MECHANISM, ENHANCES APOPTOSIS IN CLL B CELLS EX VIVO AND IDENTIFIES GSK-3 AS A POTENTIAL THERAPEUTIC TARGET IN THE TREATMENT OF CLL. 2007 6 6590 25 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 7 5795 36 STAT3 INDUCTION OF MIR-146B FORMS A FEEDBACK LOOP TO INHIBIT THE NF-KAPPAB TO IL-6 SIGNALING AXIS AND STAT3-DRIVEN CANCER PHENOTYPES. INTERLEUKIN-6 (IL-6)-MEDIATED ACTIVATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) IS A MECHANISM BY WHICH CHRONIC INFLAMMATION CAN CONTRIBUTE TO CANCER AND IS A COMMON ONCOGENIC EVENT. WE DISCOVERED A PATHWAY, THE LOSS OF WHICH IS ASSOCIATED WITH PERSISTENT STAT3 ACTIVATION IN HUMAN CANCER. WE FOUND THAT THE GENE ENCODING THE TUMOR SUPPRESSOR MICRORNA MIR-146B IS A DIRECT STAT3 TARGET GENE, AND ITS EXPRESSION WAS INCREASED IN NORMAL BREAST EPITHELIAL CELLS BUT DECREASED IN TUMOR CELLS. METHYLATION OF THE MIR-146B PROMOTER, WHICH INHIBITED STAT3-MEDIATED INDUCTION OF EXPRESSION, WAS INCREASED IN PRIMARY BREAST CANCERS. MOREOVER, WE FOUND THAT MIR-146B INHIBITED NUCLEAR FACTOR KAPPAB (NF-KAPPAB)-DEPENDENT PRODUCTION OF IL-6, SUBSEQUENT STAT3 ACTIVATION, AND IL-6/STAT3-DRIVEN MIGRATION AND INVASION IN BREAST CANCER CELLS, THEREBY ESTABLISHING A NEGATIVE FEEDBACK LOOP. IN ADDITION, HIGHER EXPRESSION OF MIR-146B WAS POSITIVELY CORRELATED WITH PATIENT SURVIVAL IN BREAST CANCER SUBTYPES WITH INCREASED IL6 EXPRESSION AND STAT3 PHOSPHORYLATION. OUR RESULTS IDENTIFY AN EPIGENETIC MECHANISM OF CROSSTALK BETWEEN STAT3 AND NF-KAPPAB RELEVANT TO CONSTITUTIVE STAT3 ACTIVATION IN MALIGNANCY AND THE ROLE OF INFLAMMATION IN ONCOGENESIS. 2014 8 439 34 ANTILEUKEMIC ACTIVITY OF VALPROIC ACID IN CHRONIC LYMPHOCYTIC LEUKEMIA B CELLS DEFINED BY MICROARRAY ANALYSIS. EPIGENETIC CODE MODIFICATIONS BY HISTONE DEACETYLASE INHIBITORS HAVE RECENTLY BEEN PROPOSED AS POTENTIAL NEW THERAPIES FOR HEMATOLOGICAL MALIGNANCIES. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) REMAINS INCURABLE DESPITE THE INTRODUCTION OF NEW TREATMENTS. CLL B CELLS ARE CHARACTERIZED BY AN APOPTOSIS DEFECT RATHER THAN EXCESSIVE PROLIFERATION, BUT PROLIFERATION CENTERS HAVE BEEN FOUND IN ORGANS SUCH AS THE BONE MARROW AND LYMPH NODES. IN THIS STUDY, WE ANALYZED GENE EXPRESSION MODIFICATIONS IN CLL B CELLS AFTER TREATMENT WITH VALPROIC ACID (VPA), A WELL-TOLERATED ANTI-EPILEPTIC DRUG WITH HDAC INHIBITORY ACTIVITY. CLL B CELLS OBTAINED FROM 14 PATIENTS WERE TREATED IN VITRO WITH A CONCENTRATION OF 1 MM VPA FOR 4 H. VPA EFFECTS ON GENE EXPRESSION WERE THEREAFTER STUDIED USING AFFYMETRIX TECHNOLOGY, AND SOME IDENTIFIED GENES WERE VALIDATED BY REAL-TIME PCR AND WESTERN BLOT. WE OBSERVED THAT VPA INDUCED APOPTOSIS BY DOWNREGULATING SEVERAL ANTI-APOPTOTIC GENES AND BY UPREGULATING PRO-APOPTOTIC GENES. FURTHERMORE, VPA SIGNIFICANTLY INCREASED CHEMOSENSITIVITY TO FLUDARABINE, FLAVOPIRIDOL, BORTEZOMIB, THALIDOMIDE AND LENALIDOMIDE. VPA INHIBITED THE PROLIFERATION OF CPG/IL2-STIMULATED CLL B CELLS AND MODULATED MANY CELL CYCLE MESSENGER RNAS. IN CONCLUSION, EXPOSURE OF CLL B CELLS TO VPA INDUCED APOPTOSIS, POTENTIATED CHEMOTHERAPEUTIC AGENT EFFECTS AND INHIBITED PROLIFERATION. THESE DATA STRONGLY SUGGEST THE USE OF VPA IN CLL TREATMENT, PARTICULARLY IN COMBINATION WITH ANTILEUKEMIA AGENTS. 2009 9 5319 36 PTEN IS FUNDAMENTAL FOR ELIMINATION OF LEUKEMIA STEM CELLS MEDIATED BY GSK126 TARGETING EZH2 IN CHRONIC MYELOGENOUS LEUKEMIA. PURPOSE: LEUKEMIA STEM CELLS (LSCS) ARE AN IMPORTANT SOURCE OF TYROSINE KINASE INHIBITOR RESISTANCE AND DISEASE RELAPSE IN PATIENTS WITH CHRONIC MYELOGENOUS LEUKEMIA (CML). TARGETING LSCS MAY BE AN ATTRACTIVE STRATEGY TO OVERRIDE THIS THORNY PROBLEM. GIVEN THAT EZH2 WAS OVEREXPRESSED IN PRIMARY CML CD34(+) CELLS, OUR PURPOSE IN THIS STUDY WAS TO EVALUATE THE EFFECTS OF TARGETING EZH2 ON CML LSCS AND CLARIFY ITS UNDERLYING MECHANISM.EXPERIMENTAL DESIGN: HUMAN PRIMARY CML CD34(+) CELLS AND RETROVIRALLY BCR-ABL-DRIVEN CML MOUSE MODELS WERE EMPLOYED TO EVALUATE THE EFFECTS OF SUPPRESSION OF EZH2 BY GSK126- OR EZH2-SPECIFIC SHRNA IN VITRO AND IN VIVO RECRUITMENT OF EZH2 AND H3K27ME3 ON THE PROMOTER OF TUMOR-SUPPRESSOR GENE PTEN IN CML CELLS WAS MEASURED BY CHROMATIN IMMUNOPRECIPITATION ASSAY.RESULTS: OUR RESULTS SHOWED THAT PHARMACOLOGIC INHIBITION OF EZH2 BY GSK126 NOT ONLY ELICITED APOPTOSIS AND RESTRICTED CELL GROWTH IN CML BULK LEUKEMIA CELLS, BUT ALSO DECREASED LSCS IN CML CD34(+) CELLS WHILE SPARING THOSE FROM NORMAL BONE MARROW CD34(+) CELLS. SUPPRESSION OF EZH2 BY GSK126 OR SPECIFIC SHRNA PROLONGED SURVIVAL OF CML MICE AND REDUCED THE NUMBER OF LSCS IN MICE. EZH2 KNOCKDOWN RESULTED IN ELEVATION OF PTEN AND LED TO IMPAIRED RECRUITMENT OF EZH2 AND H3K27ME3 ON THE PROMOTER OF PTEN GENE. THE EFFECT OF EZH2 KNOCKDOWN IN THE CML MICE WAS AT LEAST PARTIALLY REVERSED BY PTEN KNOCKDOWN.CONCLUSIONS: THESE FINDINGS IMPROVE THE UNDERSTANDING OF THE EPIGENETIC REGULATION OF STEMNESS IN CML LSCS AND WARRANT CLINICAL TRIAL OF GSK126 IN REFRACTORY PATIENTS WITH CML. CLIN CANCER RES; 24(1); 145-57. (C)2017 AACR. 2018 10 1036 24 CLASS I HISTONE DEACETYLASES REGULATE P53/NF-KAPPAB CROSSTALK IN CANCER CELLS. THE TRANSCRIPTION FACTORS NF-KAPPAB AND P53 AS WELL AS THEIR CROSSTALK DETERMINE THE FATE OF TUMOR CELLS UPON THERAPEUTIC INTERVENTIONS. REPLICATIVE STRESS AND CYTOKINES PROMOTE SIGNALING CASCADES THAT LEAD TO THE CO-REGULATION OF P53 AND NF-KAPPAB. CONSEQUENTLY, NUCLEAR P53/NF-KAPPAB SIGNALING COMPLEXES ACTIVATE NF-KAPPAB-DEPENDENT SURVIVAL GENES. THE 18 HISTONE DEACETYLASES (HDACS) ARE EPIGENETIC MODULATORS THAT FALL INTO FOUR CLASSES (I-IV). INHIBITORS OF HISTONE DEACETYLASES (HDACI) BECOME INCREASINGLY APPRECIATED AS ANTI-CANCER AGENTS. BASED ON THEIR EFFECTS ON P53 AND NF-KAPPAB, WE ADDRESSED WHETHER CLINICALLY RELEVANT HDACI AFFECT THE NF-KAPPAB/P53 CROSSTALK. THE CHEMOTHERAPEUTICS HYDROXYUREA, ETOPOSIDE, AND FLUDARABINE HALT CELL CYCLE PROGRESSION, INDUCE DNA DAMAGE, AND LEAD TO DNA FRAGMENTATION. THESE AGENTS CO-INDUCE P53 AND NF-KAPPAB-DEPENDENT GENE EXPRESSION IN CELL LINES FROM BREAST AND COLON CANCER AND IN PRIMARY CHRONIC LYMPHATIC LEUKEMIA (CLL) CELLS. USING SPECIFIC HDACI, WE FIND THAT THE CLASS I SUBGROUP OF HDACS, BUT NOT THE CLASS IIB DEACETYLASE HDAC6, ARE REQUIRED FOR THE HYDROXYUREA-INDUCED CROSSTALK BETWEEN P53 AND NF-KAPPAB. HDACI DECREASE THE BASAL AND STRESS-INDUCED EXPRESSION OF P53 AND BLOCK NF-KAPPAB-REGULATED GENE EXPRESSION. WE FURTHER SHOW THAT CLASS I HDACI INDUCE SENESCENCE IN PANCREATIC CANCER CELLS WITH MUTANT P53. 2017 11 2326 35 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 12 2435 40 EPIGENETIC SILENCING OF SFRP1 ACTIVATES THE CANONICAL WNT PATHWAY AND CONTRIBUTES TO INCREASED CELL GROWTH AND PROLIFERATION IN HEPATOCELLULAR CARCINOMA. THE WNT PATHWAY IS A KEY REGULATOR OF EMBRYONIC DEVELOPMENT AND STEM CELLS, AND ITS ABERRANT ACTIVATION IS ASSOCIATED WITH HUMAN MALIGNANCIES, MOST NOTABLY HEPATOCELLULAR CARCINOMA (HCC). EPIGENETIC DEREGULATION OF THE GENES ENCODING THE SECRETED FRIZZLED-RELATED PROTEINS (SFRPS), THE WNT SIGNALLING ANTAGONISTS, HAS BEEN LINKED WITH ABERRANT HYPERACTIVATION OF THE WNT SIGNALLING IN HCC CELLS; HOWEVER, THE PRECISE UNDERLYING MECHANISM REMAINS ELUSIVE. WE INVESTIGATED THE METHYLATION PROFILES OF WNT ANTAGONISTS IN LIVER SAMPLES OF DIFFERENT STAGES OF HCC DEVELOPMENT AND LIVER CANCER CELL LINES AND STUDIED THE FUNCTIONAL IMPACT OF ABERRANT EPIGENETIC SILENCING OF SFRPS ON THE CANONICAL WNT PATHWAY AND CELL VIABILITY. WE FOUND THAT THE SFRP1 GENE ENCODING THE SUBUNIT IS A FREQUENT TARGET OF ABERRANT DNA HYPERMETHYLATION AND SILENCING IN HCC TUMOURS, WHEREAS OTHER EXTRACELLULAR WNT ANTAGONISTS, WIF1 AND DKK3, EXHIBITED NO METHYLATION IN TUMOUR CELLS, CONSISTENT WITH THE NOTION THAT ABERRANT METHYLATION EVENTS IN CANCER CELLS ARE NON-RANDOMLY DISTRIBUTED AMONG THE GENES AND THAT THERE IS A STRONG PREFERENCE FOR HYPERMETHYLATION OF SPECIFIC GENES IN HCC. IN ADDITION, BY COMPARING SFRP1 METHYLATION STATUS IN HCC TUMOURS WITH NORMAL, CIRRHOTIC AND CHRONIC HEPATITIS LIVER TISSUES, WE IDENTIFIED SFRP1 GENE AS A POTENTIAL EARLY MARKER OF HCC. THE RESTORATION OF SFRP1 EXPRESSION IN CANCER CELLS BY ECTOPIC EXPRESSION INHIBITED WNT ACTIVITY ACCOMPANIED WITH DESTABILIZATION OF BETA-CATENIN AND DOWNREGULATION OF C-MYC AND CYCLIN D1, THE KNOWN DOWNSTREAM TARGETS OF WNT PATHWAY. IMPORTANTLY, RESTORING SFRP1 LEVELS IN CANCER CELLS INHIBITED CELL GROWTH AND INDUCED APOPTOTIC CELL DEATH. THIS STUDY SUPPORTS THE CRITICAL ROLE FOR SFRP1 SILENCING IN HEPATOCELLULAR CARCINOMA AND REINFORCES THE IMPORTANCE OF THE WNT ANTAGONISTS IN PREVENTING ONCOGENIC STABILIZATION OF BETA-CATENIN AND CHRONIC ACTIVATION OF THE CANONICAL WNT PATHWAY, SUGGESTING THAT SFRP1 MAY BE AN ATTRACTIVE TARGET FOR EARLY CANCER DETECTION AND THERAPEUTIC INTERVENTION. 2012 13 1333 26 DEREGULATION AND EPIGENETIC MODIFICATION OF BCL2-FAMILY GENES CAUSE RESISTANCE TO VENETOCLAX IN HEMATOLOGIC MALIGNANCIES. THE BCL2 INHIBITOR VENETOCLAX HAS BEEN APPROVED TO TREAT DIFFERENT HEMATOLOGICAL MALIGNANCIES. BECAUSE THERE IS NO COMMON GENETIC ALTERATION CAUSING RESISTANCE TO VENETOCLAX IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND B-CELL LYMPHOMA, WE ASKED IF EPIGENETIC EVENTS MIGHT BE INVOLVED IN VENETOCLAX RESISTANCE. THEREFORE, WE EMPLOYED WHOLE-EXOME SEQUENCING, METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING, AND GENOME-WIDE CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR)/CRISPR-ASSOCIATED PROTEIN 9 SCREENING TO INVESTIGATE VENETOCLAX RESISTANCE IN AGGRESSIVE LYMPHOMA AND HIGH-RISK CLL PATIENTS. WE IDENTIFIED A REGULATORY CPG ISLAND WITHIN THE PUMA PROMOTER THAT IS METHYLATED UPON VENETOCLAX TREATMENT, MEDIATING PUMA DOWNREGULATION ON TRANSCRIPT AND PROTEIN LEVEL. PUMA EXPRESSION AND SENSITIVITY TOWARD VENETOCLAX CAN BE RESTORED BY INHIBITION OF METHYLTRANSFERASES. WE CAN DEMONSTRATE THAT LOSS OF PUMA RESULTS IN METABOLIC REPROGRAMMING WITH HIGHER OXIDATIVE PHOSPHORYLATION AND ADENOSINE TRIPHOSPHATE PRODUCTION, RESEMBLING THE METABOLIC PHENOTYPE THAT IS SEEN UPON VENETOCLAX RESISTANCE. ALTHOUGH PUMA LOSS IS SPECIFIC FOR ACQUIRED VENETOCLAX RESISTANCE BUT NOT FOR ACQUIRED MCL1 RESISTANCE AND IS NOT SEEN IN CLL PATIENTS AFTER CHEMOTHERAPY-RESISTANCE, BAX IS ESSENTIAL FOR SENSITIVITY TOWARD BOTH VENETOCLAX AND MCL1 INHIBITION. AS WE FOUND LOSS OF BAX IN RICHTER'S SYNDROME PATIENTS AFTER VENETOCLAX FAILURE, WE DEFINED BAX-MEDIATED APOPTOSIS TO BE CRITICAL FOR DRUG RESISTANCE BUT NOT FOR DISEASE PROGRESSION OF CLL INTO AGGRESSIVE DIFFUSE LARGE B-CELL LYMPHOMA IN VIVO. A COMPOUND SCREEN REVEALED TRAIL-MEDIATED APOPTOSIS AS A TARGET TO OVERCOME BAX DEFICIENCY. FURTHERMORE, ANTIBODY OR CAR T CELLS ELIMINATED VENETOCLAX RESISTANT LYMPHOMA CELLS, PAVING A CLINICALLY APPLICABLE WAY TO OVERCOME VENETOCLAX RESISTANCE. 2022 14 6455 29 THYMOQUINONE ENHANCES APOPTOSIS OF K562 CHRONIC MYELOID LEUKEMIA CELLS THROUGH HYPOMETHYLATION OF SHP-1 AND INHIBITION OF JAK/STAT SIGNALING PATHWAY. THE EPIGENETIC SILENCING OF TUMOR SUPPRESSOR GENES (TSGS) IS CRITICAL IN THE DEVELOPMENT OF CHRONIC MYELOID LEUKEMIA (CML). SHP-1 FUNCTIONS AS A TSG AND NEGATIVELY REGULATES JAK/STAT SIGNALING. ENHANCEMENT OF SHP-1 EXPRESSION BY DEMETHYLATION PROVIDES MOLECULAR TARGETS FOR THE TREATMENT OF VARIOUS CANCERS. THYMOQUINONE (TQ), A CONSTITUENT OF NIGELLA SATIVA SEEDS, HAS SHOWN ANTI-CANCER ACTIVITIES IN VARIOUS CANCERS. HOWEVER, TQS EFFECT ON METHYLATION IS NOT FULLY CLEAR. THEREFORE, THE AIM OF THIS STUDY IS TO ASSESS TQS ABILITY TO ENHANCE THE EXPRESSION OF SHP-1 THROUGH MODIFYING DNA METHYLATION IN K562 CML CELLS. THE ACTIVITIES OF TQ ON CELL CYCLE PROGRESSION AND APOPTOSIS WERE EVALUATED USING A FLUOROMETRIC-RED CELL CYCLE ASSAY AND ANNEXIN V-FITC/PI, RESPECTIVELY. THE METHYLATION STATUS OF SHP-1 WAS STUDIED BY PYROSEQUENCING ANALYSIS. THE EXPRESSION OF SHP-1, TET2, WT1, DNMT1, DNMT3A, AND DNMT3B WAS DETERMINED USING RT-QPCR. THE PROTEIN PHOSPHORYLATION OF STAT3, STAT5, AND JAK2 WAS ASSESSED USING JESS WESTERN ANALYSIS. TQ SIGNIFICANTLY DOWNREGULATED THE DNMT1 GENE, DNMT3A GENE, AND DNMT3B GENE AND UPREGULATED THE WT1 GENE AND TET2 GENE. THIS LED TO HYPOMETHYLATION AND RESTORATION OF SHP-1 EXPRESSION, RESULTING IN INHIBITION OF JAK/STAT SIGNALING, INDUCTION OF APOPTOSIS, AND CELL CYCLE ARREST. THE OBSERVED FINDINGS IMPLY THAT TQ PROMOTES APOPTOSIS AND CELL CYCLE ARREST IN CML CELLS BY INHIBITING JAK/STAT SIGNALING VIA RESTORATION OF THE EXPRESSION OF JAK/STAT-NEGATIVE REGULATOR GENES. 2023 15 2081 35 EPIGENETIC DOWN-REGULATION OF BIM EXPRESSION IS ASSOCIATED WITH REDUCED OPTIMAL RESPONSES TO IMATINIB TREATMENT IN CHRONIC MYELOID LEUKAEMIA. BACKGROUND: EXPRESSION OF THE PRO-APOPTOTIC BCL-2-INTERACTING MEDIATOR (BIM) HAS RECENTLY BEEN IMPLICATED IN IMATINIB-INDUCED APOPTOSIS OF BCR-ABL1(+) CELLS. HOWEVER, THE MECHANISMS INVOLVED IN THE REGULATION OF BIM IN CML AND ITS ROLE IN THE CLINICAL SETTING HAVE NOT BEEN ESTABLISHED. DESIGN AND METHODS: WE ANALYSED THE MRNA EXPRESSION OF BIM IN 100 NEWLY DIAGNOSED PATIENTS WITH CML IN CHRONIC PHASE BY Q-RT-PCR AND THE PROTEIN LEVELS BY WESTERN BLOT ANALYSIS. METHYLATION STATUS WAS ANALYSED BY BISULPHITE GENOMIC SEQUENCING AND MSP. CML CELL LINES WERE TREATED WITH IMATINIB AND 5-AZA-2'-DEOXYCYTIDINE, AND WERE TRANSFECTED WITH TWO DIFFERENT SIRNAS AGAINST BIM AND CELL PROLIFERATION AND APOPTOSIS WERE ANALYSED. RESULTS: WE DEMONSTRATED THAT DOWN-REGULATION OF BIM EXPRESSION WAS PRESENT IN 36% OF THE PATIENTS AND WAS SIGNIFICANTLY ASSOCIATED WITH A LACK OF OPTIMAL RESPONSE TO IMATINIB AS INDICATED BY THE DECREASE IN CYTOGENETIC AND MOLECULAR RESPONSES AT 6, 12 AND 18 MONTHS IN COMPARISON WITH PATIENTS WITH NORMAL BIM EXPRESSION (P<0.05). EXPRESSION OF BIM WAS MEDIATED BY PROMOTER HYPERMETHYLATION AS DEMONSTRATED BY RESTORATION OF BIM EXPRESSION AFTER TREATMENT OF CML CELLS WITH 5-AZA-2'-DEOXYCYTIDINE. USING CML CELL LINES WITH LOW AND NORMAL EXPRESSION OF BIM WE FURTHER DEMONSTRATED THAT THE EXPRESSION OF BIM IS REQUIRED FOR IMATINIB-INDUCED CML APOPTOSIS. CONCLUSION: OUR DATA INDICATE THAT DOWN-REGULATION OF BIM IS EPIGENETICALLY CONTROLLED BY METHYLATION IN A PERCENTAGE OF CML PATIENTS AND HAS AN UNFAVOURABLE PROGNOSTIC IMPACT, AND THAT THE COMBINATION OF IMATINIB WITH A DE-METHYLATING AGENT MAY RESULT IN IMPROVED RESPONSES IN PATIENTS WITH DECREASED EXPRESSION OF BIM. 2009 16 6444 36 THERAPEUTIC ASPECTS OF C-MYC SIGNALING IN INFLAMMATORY AND CANCEROUS COLONIC DISEASES. COLONIC INFLAMMATION IS REQUIRED TO HEAL INFECTIONS, WOUNDS, AND MAINTAIN TISSUE HOMEOSTASIS. AS THE SEVENTH HALLMARK OF CANCER, HOWEVER, IT MAY AFFECT ALL PHASES OF TUMOR DEVELOPMENT, INCLUDING TUMOR INITIATION, PROMOTION, INVASION AND METASTATIC DISSEMINATION, AND ALSO EVASION IMMUNE SURVEILLANCE. INFLAMMATION ACTS AS A CELLULAR STRESSOR AND MAY TRIGGER DNA DAMAGE OR GENETIC INSTABILITY, AND, FURTHER, CHRONIC INFLAMMATION CAN PROVOKE GENETIC MUTATIONS AND EPIGENETIC MECHANISMS THAT PROMOTE MALIGNANT CELL TRANSFORMATION. BOTH SPORADICAL AND COLITIS-ASSOCIATED COLORECTAL CARCINOGENESIS ARE MULTI-STEP, COMPLEX PROCESSES ARISING FROM THE UNCONTROLLED PROLIFERATION AND SPREADING OF MALIGNANTLY TRANSFORMED CELL CLONES WITH THE OBVIOUS ABILITY TO EVADE THE HOST'S PROTECTIVE IMMUNITY. IN CELLS UPON DNA DAMAGE SEVERAL PROTO-ONCOGENES, INCLUDING C-MYC ARE ACTIVATED IN PARELELL WITH THE INACTIVATION OF TUMOR SUPPRESSOR GENES. THE TARGET GENES OF THE C-MYC PROTEIN PARTICIPATE IN DIFFERENT CELLULAR FUNCTIONS, INCLUDING CELL CYCLE, SURVIVAL, PROTEIN SYNTHESIS, CELL ADHESION, AND MICRO-RNA EXPRESSION. THE TRANSCRIPTIONAL PROGRAM REGULATED BY C-MYC IS CONTEXT DEPENDENT, THEREFORE THE FINAL CELLULAR RESPONSE TO ELEVATED C-MYC LEVELS MAY RANGE FROM INCREASED PROLIFERATION TO AUGMENTED APOPTOSIS. CONSIDERING PHYSIOLOGICAL INTESTINAL HOMEOSTASIS, C-MYC DISPLAYS A FUNDAMENTAL ROLE IN THE REGULATION OF CELL PROLIFERATION AND CRYPT CELL NUMBER. HOWEVER, C-MYC GENE IS FREQUENTLY DEREGULATED IN INFLAMMATION, AND OVEREXPRESSED IN BOTH SPORADIC AND COLITIS-ASSOCIATED COLON ADENOCARCINOMAS. RECENT RESULTS DEMONSTRATED THAT ENDOGENOUS C-MYC IS ESSENTIAL FOR EFFICIENT INDUCTION OF P53-DEPENDENT APOPTOSIS FOLLOWING DNA DAMAGE, BUT C-MYC FUNCTION IS ALSO INVOLVED IN AND REGULATED BY AUTOPHAGY-RELATED MECHANISMS, WHILE ITS EXPRESSION IS AFFECTED BY DNA-METHYLATION, OR HISTONE ACETYLATION. MOLECULES DIRECTLY TARGETING C-MYC, OR AGENTS ACTING ON OTHER GENES INVOLVED IN THE C-MYC PATHWAY COULD BE SELECTED FOR COMBINED REGIMENTS. HOWEVER, DUE TO ITS CONTEXT-DEPENDENT CELLULAR FUNCTION, IT IS CLINICALLY ESSENTIAL TO CONSIDER WHICH CYTOTOXIC DRUGS ARE USED IN COMBINATION WITH C-MYC TARGETED AGENTS IN VARIOUS TISSUES. INCREASING OUR KNOWLEDGE ABOUT MYC-DEPENDENT PATHWAYS MIGHT PROVIDE DIRECTION TO NOVEL ANTI-INFLAMMATORY AND COLORECTAL CANCER THERAPIES. 2016 17 5479 38 RESVERATROL ATTENUATES CIGARETTE SMOKE EXTRACT INDUCED CELLULAR SENESCENCE IN HUMAN AIRWAY EPITHELIAL CELLS BY REGULATING THE MIR-34A/SIRT1/NF-KAPPAB PATHWAY. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS CHARACTERIZED BY ACCELERATED LUNG AGING. SMOKING IS THE CRITICAL RISK FACTOR FOR COPD. CELLULAR SENESCENCE OF AIRWAY EPITHELIAL CELLS IS THE CYTOLOGICAL BASIS OF ACCELERATED LUNG AGING IN COPD, AND THE REGULATION OF MICRORNAS (MIRNAS) IS THE CENTRAL EPIGENETIC MECHANISM OF CELLULAR SENESCENCE. RESVERATROL (RES) IS A POLYPHENOL WITH ANTI-AGING PROPERTIES. THIS STUDY INVESTIGATED WHETHER RES ATTENUATES CIGARETTE SMOKE EXTRACT (CSE)-INDUCED CELLULAR SENESCENCE IN HUMAN AIRWAY EPITHELIAL CELLS (BEAS-2B) THROUGH THE MIR-34A/SIRT1/NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) PATHWAY. BEAS-2B CELLS WERE TREATED WITH RES, CSE AND TRANSFECTED WITH MIR-34A-5P MIMICS. CELLULAR SENESCENCE WAS EVALUATED BY SENESCENCE -RELATED BETA-GALACTOSIDASE (SA-BETA-GAL) STAINING AND EXPRESSION OF SENESCENCE-RELATED GENES (P16, P21, AND P53). THE EXPRESSIONS OF MIR-34A-5P, SIRT1, AND NF-KAPPAB P65 WERE EXAMINED USING QUANTITATIVE REAL TIME POLYMERASE CHAIN REACTION AND WESTERN BLOTTING. THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP) CYTOKINES (IL-1BETA, IL-6, IL-8, TNF-ALPHA) WERE ASSESSED BY ENZYME-LINKED IMMUNOSORBENT ASSAY. THE BINDING BETWEEN MIR-34A-5P AND SIRT1 WAS CONFIRMED BY DUAL-LUCIFERASE REPORTER ASSAY. THE RESULTS SHOWED THAT CSE DOSE-DEPENDENTLY DECREASED CELL VIABILITY AND ELEVATED CELLULAR SENESCENCE, CHARACTERIZED BY INCREASED SA-BETA-GAL STAINING AND SENESCENCE-RELATED GENE EXPRESSIONS (P16, P21, AND P53). FURTHER, CSE DOSE-DEPENDENTLY INCREASED THE EXPRESSION OF MIR-34A-5P AND SASP CYTOKINES (IL-1BETA, IL-6, IL-8, TNF-ALPHA) IN BEAS-2B CELLS. PRETREATMENT WITH RES INHIBITED CSE-INDUCED CELLULAR SENESCENCE AND SECRETION OF SASP CYTOKINES (IL-1BETA, IL-6, IL-8, TNF-ALPHA) IN A DOSE-DEPENDENT MANNER. MOREOVER, RES REVERSED THE CSE-INDUCED DOWN-REGULATION OF SIRT1 AND UP-REGULATION OF MIR-34A-5P AND NF-KAPPAB P65. SIRT1 IS A TARGET OF MIR-34A-5P. OVEREXPRESSION OF MIR-34A-5P VIA TRANSFECTION WITH MIR-34A-5P MIMIC IN BEAS-2B CELLS ATTENUATED THE INHIBITORY EFFECT OF RES ON CELLULAR SENESCENCE, ACCOMPANIED BY REVERSING THE EXPRESSION OF SIRT1 AND NF-KAPPAB P65. IN CONCLUSION, RES ATTENUATED CSE-INDUCED CELLULAR SENESCENCE IN BEAS-2B CELLS BY REGULATING THE MIR-34A/SIRT1/NF-KAPPAB PATHWAY, WHICH MAY PROVIDE A NEW APPROACH FOR COPD TREATMENT. 2022 18 4899 28 OXIDATIVE STRESS MEDIATES THE APOPTOSIS AND EPIGENETIC MODIFICATION OF THE BCL-2 PROMOTER VIA DNMT1 IN A CIGARETTE SMOKE-INDUCED EMPHYSEMA MODEL. BACKGROUND: EMPHYSEMA IS A CRUCIAL PATHOLOGICAL CHARACTERISTIC OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). OXIDATIVE STRESS, APOPTOSIS AND EPIGENETIC MECHANISMS CONTRIBUTE TO THE PATHOGENESIS OF EMPHYSEMA. HOWEVER, AN ATTEMPT TO ACCURATELY IDENTIFY WHETHER THESE MECHANISMS INTERACT WITH EACH OTHER AND HOW THEY ARE TRIGGERED HAS NEVER BEEN CONDUCTED. METHOD: THE TOTAL REACTIVE OXYGEN SPECIES (ROS) LEVEL, PULMONARY APOPTOSIS AND B-CELL LYMPHOMA/LEUKEMIA-2 (BCL-2) EXPRESSION, AN APOPTOSIS REGULATOR, WERE DETECTED IN SAMPLES FROM COPD PATIENTS. BISULFITE SEQUENCING PCR (BSP) WAS CONDUCTED TO OBSERVE THE ALTERATIONS IN THE METHYLATION OF THE BCL-2 PROMOTER IN SPECIMENS. THE DYSREGULATION OF DNA METHYLTRANSFERASE ENZYME 1 (DNMT1), A VITAL DNA METHYLTRANSFERASE ENZYME, IN THE LUNGS OF PATIENTS WAS CONFIRMED THROUGH WESTERN BLOTTING. TO FIND OUT INTERACTIONS BETWEEN OXIDATIVE STRESS AND DNA METHYLATION IN EMPHYSEMA, MOUSE MODELS WERE BUILT WITH ANTIOXIDANT TREATMENT AND DNMT1 SILENCING, AND WERE EXAMINED WITH THE PULMONARY APOPTOSIS, BCL-2 AND DNMT1 LEVELS, AND EPIGENETIC ALTERATIONS OF BCL-2. RESULTS: HIGHER ROS LEVELS AND PULMONARY APOPTOSIS WERE OBSERVED IN COPD PATIENTS THAN IN HEALTHY CONTROLS. DOWNREGULATED BCL-2 EXPRESSION WITH INCREASED PROMOTER METHYLATION AND DNMT1 PROTEIN EXPRESSION WAS FOUND IN COPD PATIENTS. ANTIOXIDANT TREATMENT REDUCED THE LEVEL OF ROS, DNMT1 PROTEIN AND EMPHYSEMATOUS PROGRESSION IN THE SMOKING MODELS. FOLLOWING DNMT1 BLOCKADE, SMOKING MODELS SHOWED IMPROVED LUNG FUNCTION, PULMONARY APOPTOSIS, EMPHYSEMATOUS PROGRESSION, AND INCREASED BCL-2 PROTEIN LEVEL WITH LESS PROMOTER METHYLATION THAN EMPHYSEMA MICE. CONCLUSION: CIGARETTE-INDUCED OXIDATIVE STRESS MEDIATES PULMONARY APOPTOSIS AND HYPERMETHYLATION OF THE BCL-2 PROMOTER IN EMPHYSEMA MODELS THROUGH DNMT1. 2020 19 6688 32 VALPROATE SYNERGIZES WITH PURINE NUCLEOSIDE ANALOGUES TO INDUCE APOPTOSIS OF B-CHRONIC LYMPHOCYTIC LEUKAEMIA CELLS. RESISTANCE TO CHEMOTHERAPY AND DRUG TOXICITY ARE TWO MAJOR CONCERNS OF CHRONIC LYMPHOCYTIC LEUKAEMIA (B-CLL) TREATMENT BY PURINE NUCLEOSIDE ANALOGUES (PNA, I.E. FLUDARABINE AND CLADRIBINE). WE HYPOTHESIZED THAT TARGETING EPIGENETIC CHANGES MIGHT ADDRESS THESE ISSUES AND EVALUATED THE EFFECT OF THE HISTONE DEACETYLASE INHIBITOR VALPROATE (VPA) AT A CLINICALLY RELEVANT CONCENTRATION. VPA ACTED IN A HIGHLY SYNERGISTIC/ADDITIVE MANNER WITH FLUDARABINE AND CLADRIBINE TO INDUCE APOPTOSIS OF B-CLL CELLS. IMPORTANTLY, VPA ALSO RESTORED SENSITIVITY TO FLUDARABINE IN B CELLS FROM POOR PROGNOSIS CLL PATIENTS WHO BECAME RESISTANT TO CHEMOTHERAPY. MECHANISM OF APOPTOSIS INDUCED BY VPA ALONE OR COMBINED WITH FLUDARABINE OR TO CLADRIBINE WAS CASPASE-DEPENDENT AND INVOLVED THE EXTRINSIC PATHWAY. VPA, BUT NEITHER FLUDARABINE NOR CLADRIBINE, ENHANCED THE PRODUCTION OF REACTIVE OXYGEN SPECIES (ROS) AND INHIBITION OF ROS WITH N-ACETYLCYSTEINE DECREASES APOPTOSIS OF CLL CELLS. VPA STIMULATES HYPERPHOSPHORYLATION OF P42/P44 ERK, CYTOCHROME C RELEASE AND OVEREXPRESSION OF BAX AND FAS. TOGETHER, OUR DATA INDICATE THAT VPA MAY AMELIORATE THE OUTCOME OF PNA-BASED THERAPEUTIC PROTOCOLS AND PROVIDE A POTENTIAL ALTERNATIVE TREATMENT IN BOTH THE RELAPSED AND FRONT-LINE RESISTANT PATIENTS AND IN PATIENTS WITH HIGH RISK FEATURES. 2009 20 699 33 BROMODOMAIN PROTEIN 4 IS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HEPATIC STELLATE CELL ACTIVATION. LIVER FIBROSIS IS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX IN LIVER. CHRONIC LIVER INJURY INDUCES THE ACTIVATION OF HEPATIC STELLATE CELL (HSCS), A KEY STEP IN LIVER FIBROGENESIS. THE ACTIVATED HSC IS THE PRIMARY SOURCE OF ECM AND CONTRIBUTES SIGNIFICANTLY TO LIVER FIBROSIS. TGFBETA1 IS THE MOST POTENT PRO-FIBROTIC CYTOKINE. BROMODOMAIN PROTEIN 4 (BRD4), AN EPIGENETIC READER OF HISTONE ACETYLATION MARKS, WAS CRUCIAL FOR PROFIBROTIC GENE EXPRESSION IN HSCS. THE PRESENT STUDY AIMED TO INVESTIGATE THE ROLES OF BRD4 IN TGFBETA1-DEPENDENT HSC ACTIVATION AND LIVER FIBROSIS, FOCUSING ON TGFBETA1-INDUCED ALTERATIONS OF THE LEVELS OF THE FIBROTIC-RELATED IMPORTANT PROTEINS IN HSCS BY EMPLOYING THE HETEROZYGOUS TGFBETA1 KNOCKOUT MICE AND BRD4 KNOCKDOWN IN VIVO AND IN VITRO. RESULTS REVEALED THAT BRD4 PROTEIN LEVEL WAS SIGNIFICANTLY UPREGULATED BY TGFBETA1 AND BRD4 KNOCKDOWN REDUCED TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. BRD4 WAS REQUIRED FOR THE INFLUENCES OF TGFBETA1 ON PDGFBETA RECEPTOR AND ON THE PATHWAYS OF SMAD3, STAT3, AND AKT. BRD4 ALSO MEDIATED TGFBETA1-INDUCED INCREASES IN HISTONE ACETYLTRANSFERASE P300, THE PIVOTAL PRO-INFLAMMATORY NFKB P65, AND TISSUE INHIBITOR OF METALLOPROTEINASE 1 WHEREAS BRD4 REDUCED CASPASE-3 PROTEIN LEVELS IN HSCS DURING LIVER INJURY, INDEPENDENT OF TGFBETA1. FURTHER EXPERIMENTS INDICATED THE INTERACTION BETWEEN TGFBETA1-INDUCED BRD4 AND NFKB P65 IN HSCS AND IN LIVER OF TAA-INDUCED LIVER INJURY. HUMAN CIRRHOTIC LIVERS WERE DEMONSTRATED A PARALLEL INCREASE IN THE PROTEIN LEVELS OF BRD4 AND NFKB P65 IN HSCS. THIS STUDY REVEALED THAT BRD4 WAS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. 2023