1 6659 144 UPREGULATION OF AKT3 CONFERS RESISTANCE TO THE AKT INHIBITOR MK2206 IN BREAST CANCER. ACQUIRED RESISTANCE TO MOLECULAR TARGETED THERAPY REPRESENTS A MAJOR CHALLENGE FOR THE EFFECTIVE TREATMENT OF CANCER. HYPERACTIVATION OF THE PI3K/AKT PATHWAY IS FREQUENTLY OBSERVED IN VIRTUALLY ALL HUMAN MALIGNANCIES, AND NUMEROUS PI3K AND AKT INHIBITORS ARE CURRENTLY UNDER CLINICAL EVALUATION. HOWEVER, MECHANISMS OF ACQUIRED RESISTANCE TO AKT INHIBITORS HAVE YET TO BE DESCRIBED. HERE, WE USE A BREAST CANCER PRECLINICAL MODEL TO IDENTIFY RESISTANCE MECHANISMS TO A SMALL MOLECULE ALLOSTERIC AKT INHIBITOR, MK2206. USING A STEP-WISE AND CHRONIC HIGH-DOSE EXPOSURE, BREAST CANCER CELL LINES HARBORING ONCOGENIC PI3K RESISTANT TO MK2206 WERE ESTABLISHED. USING THIS MODEL, WE REVEAL THAT AKT3 EXPRESSION IS MARKEDLY UPREGULATED IN AKT INHIBITOR-RESISTANT CELLS. INDUCTION OF AKT3 IS REGULATED EPIGENETICALLY BY THE BROMODOMAIN AND EXTRA TERMINAL DOMAIN PROTEINS. IMPORTANTLY, KNOCKDOWN OF AKT3, BUT NOT AKT1 OR AKT2, IN RESISTANT CELLS RESTORES SENSITIVITY TO MK2206. AKT INHIBITOR-RESISTANT CELLS ALSO DISPLAY AN EPITHELIAL TO MESENCHYMAL TRANSITION PHENOTYPE AS ASSESSED BY ALTERATIONS IN THE LEVELS OF E-CADHERIN, N-CADHERIN, AND VIMENTIN, AS WELL AS ENHANCED INVASIVENESS OF TUMOR SPHEROIDS. NOTABLY, THE INVASIVE MORPHOLOGY OF RESISTANT SPHEROIDS IS DIMINISHED UPON AKT3 DEPLETION. WE ALSO SHOW THAT RESISTANCE TO MK2206 IS REVERSIBLE BECAUSE UPON DRUG REMOVAL RESISTANT CELLS REGAIN SENSITIVITY TO AKT INHIBITION, ACCOMPANIED BY REEXPRESSION OF EPITHELIAL MARKERS AND REDUCTION OF AKT3 EXPRESSION, IMPLYING THAT EPIGENETIC REPROGRAMMING CONTRIBUTES TO ACQUISITION OF RESISTANCE. THESE FINDINGS PROVIDE A RATIONALE FOR DEVELOPING THERAPEUTICS TARGETING AKT3 TO CIRCUMVENT ACQUIRED RESISTANCE IN BREAST CANCER. MOL CANCER THER; 15(8); 1964-74. (C)2016 AACR. 2016 2 4867 35 OSSIFYING FIBROMA TUMOR STEM CELLS ARE MAINTAINED BY EPIGENETIC REGULATION OF A TSP1/TGF-BETA/SMAD3 AUTOCRINE LOOP. ABNORMAL STEM CELL FUNCTION MAKES A KNOWN CONTRIBUTION TO MANY MALIGNANT TUMORS, BUT THE ROLE OF STEM CELLS IN BENIGN TUMORS IS NOT WELL UNDERSTOOD. HERE, WE SHOW THAT OSSIFYING FIBROMA (OF) CONTAINS A STEM CELL POPULATION THAT RESEMBLES MESENCHYMAL STEM CELLS (OFMSCS) AND IS CAPABLE OF GENERATING OF-LIKE TUMOR XENOGRAFTS. MECHANISTICALLY, OFMSCS SHOW ENHANCED TGF-BETA SIGNALING THAT INDUCES ABERRANT PROLIFERATION AND DEFICIENT OSTEOGENESIS VIA NOTCH AND BMP SIGNALING PATHWAYS, RESPECTIVELY. THE ELEVATED TGF-BETA ACTIVITY IS TIGHTLY REGULATED BY JHDM1D-MEDIATED EPIGENETIC REGULATION OF THROMBOSPONDIN-1 (TSP1), FORMING A JHDM1D/TSP1/TGF-BETA/SMAD3 AUTOCRINE LOOP. INHIBITION OF TGF-BETA SIGNALING IN OFMSCS CAN RESCUE THEIR ABNORMAL OSTEOGENIC DIFFERENTIATION AND ELEVATED PROLIFERATION RATE. FURTHERMORE, CHRONIC ACTIVATION OF TGF-BETA CAN CONVERT NORMAL MSCS INTO OF-LIKE MSCS VIA ESTABLISHMENT OF THIS JHDM1D/TSP1/TGF-BETA/SMAD3 AUTOCRINE LOOP. THESE RESULTS REVEAL THAT EPIGENETIC REGULATION OF TGF-BETA SIGNALING IN MSCS GOVERNS THE BENIGN TUMOR PHENOTYPE IN OF AND HIGHLIGHT TGF-BETA SIGNALING AS A CANDIDATE THERAPEUTIC TARGET. 2013 3 5101 35 POLYCOMB FACTOR PHF19 CONTROLS CELL GROWTH AND DIFFERENTIATION TOWARD ERYTHROID PATHWAY IN CHRONIC MYELOID LEUKEMIA CELLS. POLYCOMB GROUP (PCG) OF PROTEINS ARE A GROUP OF HIGHLY CONSERVED EPIGENETIC REGULATORS INVOLVED IN MANY BIOLOGICAL FUNCTIONS, SUCH AS EMBRYONIC DEVELOPMENT, CELL PROLIFERATION, AND ADULT STEM CELL DETERMINATION. PHD FINGER PROTEIN 19 (PHF19) IS AN ASSOCIATED FACTOR OF POLYCOMB REPRESSOR COMPLEX 2 (PRC2), OFTEN UPREGULATED IN HUMAN CANCERS. IN PARTICULAR, MYELOID LEUKEMIA CELL LINES SHOW INCREASED LEVELS OF PHF19, YET LITTLE IS KNOWN ABOUT ITS FUNCTION. HERE, WE HAVE CHARACTERIZED THE ROLE OF PHF19 IN MYELOID LEUKEMIA CELLS. WE DEMONSTRATED THAT PHF19 DEPLETION DECREASES CELL PROLIFERATION AND PROMOTES CHRONIC MYELOID LEUKEMIA (CML) DIFFERENTIATION. MECHANISTICALLY, WE HAVE SHOWN HOW PHF19 REGULATES THE PROLIFERATION OF CML THROUGH A DIRECT REGULATION OF THE CELL CYCLE INHIBITOR P21. FURTHERMORE, WE OBSERVED THAT MTF2, A PHF19 HOMOLOG, PARTIALLY COMPENSATES FOR PHF19 DEPLETION IN A SUBSET OF TARGET GENES, INSTRUCTING SPECIFIC ERYTHROID DIFFERENTIATION. TAKEN TOGETHER, OUR RESULTS SHOW THAT PHF19 IS A KEY TRANSCRIPTIONAL REGULATOR FOR CELL FATE DETERMINATION AND COULD BE A POTENTIAL THERAPEUTIC TARGET FOR MYELOID LEUKEMIA TREATMENT. 2021 4 1334 27 DEREGULATION OF AIOLOS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS THAT ARE RESISTANT TO APOPTOSIS. AIOLOS, A MEMBER OF THE IKAROS FAMILY OF ZINC-FINGER TRANSCRIPTION FACTORS, PLAYS AN IMPORTANT ROLE IN THE CONTROL OF MATURE B LYMPHOCYTE DIFFERENTIATION AND MATURATION. IN THIS STUDY, WE SHOWED THAT AIOLOS EXPRESSION IS UP-REGULATED IN B-CLL CELLS. THIS OVEREXPRESSION DOES NOT IMPLICATE ISOFORM IMBALANCE OR DISTURB AIOLOS SUBCELLULAR LOCALIZATION. THE CHROMATIN STATUS AT THE AIOLOS PROMOTER IN CLL IS DEFINED BY THE DEMETHYLATION OF DNA AND AN ENRICHMENT OF EUCHROMATIN ASSOCIATED HISTONE MARKERS, SUCH AS THE DIMETHYLATION OF THE LYSINE 4 ON HISTONE H3. THESE EPIGENETIC MODIFICATIONS SHOULD ALLOW ITS UPSTREAM EFFECTORS, SUCH AS NUCLEAR FACTOR-KAPPAB, CONSTITUTIVELY ACTIVATED IN CLL, TO GAIN ACCESS TO PROMOTER, RESULTING UP-REGULATION OF AIOLOS. TO DETERMINE THE CONSEQUENCES OF AIOLOS DEREGULATION IN CLL, WE ANALYZED THE EFFECTS OF AIOLOS OVEREXPRESSION OR DOWN-REGULATION ON APOPTOSIS. AIOLOS IS INVOLVED IN CELL SURVIVAL BY REGULATING THE EXPRESSION OF SOME BCL-2 FAMILY MEMBERS. OUR RESULTS STRONGLY SUGGEST THAT AIOLOS DEREGULATION BY EPIGENETIC MODIFICATIONS MAY BE A HALLMARK OF CLL. 2011 5 5788 34 SREBP1 DRIVES KERATIN-80-DEPENDENT CYTOSKELETAL CHANGES AND INVASIVE BEHAVIOR IN ENDOCRINE-RESISTANT ERALPHA BREAST CANCER. APPROXIMATELY 30% OF ERALPHA BREAST CANCER PATIENTS RELAPSE WITH METASTATIC DISEASE FOLLOWING ADJUVANT ENDOCRINE THERAPIES. THE CONNECTION BETWEEN ACQUISITION OF DRUG RESISTANCE AND INVASIVE POTENTIAL IS POORLY UNDERSTOOD. IN THIS STUDY, WE DEMONSTRATE THAT THE TYPE II KERATIN TOPOLOGICAL ASSOCIATING DOMAIN UNDERGOES EPIGENETIC REPROGRAMMING IN AROMATASE INHIBITORS (AI)-RESISTANT CELLS, LEADING TO KERATIN-80 (KRT80) UPREGULATION. KRT80 EXPRESSION IS DRIVEN BY DE NOVO ENHANCER ACTIVATION BY STEROL REGULATORY ELEMENT-BINDING PROTEIN 1 (SREBP1). KRT80 UPREGULATION DIRECTLY PROMOTES CYTOSKELETAL REARRANGEMENTS AT THE LEADING EDGE, INCREASED FOCAL ADHESION AND CELLULAR STIFFENING, COLLECTIVELY PROMOTING CANCER CELL INVASION. SHEARWAVE ELASTICITY IMAGING PERFORMED ON PROSPECTIVELY RECRUITED PATIENTS CONFIRMS KRT80 LEVELS CORRELATE WITH STIFFER TUMORS. IMMUNOHISTOCHEMISTRY SHOWED INCREASED KRT80-POSITIVE CELLS AT RELAPSE AND, USING SEVERAL CLINICAL ENDPOINTS, KRT80 EXPRESSION ASSOCIATES WITH POOR SURVIVAL. COLLECTIVELY, OUR DATA UNCOVER AN UNPREDICTED AND POTENTIALLY TARGETABLE DIRECT LINK BETWEEN EPIGENETIC AND CYTOSKELETAL REPROGRAMMING PROMOTING CELL INVASION IN RESPONSE TO CHRONIC AI TREATMENT. 2019 6 5433 28 REL/NF-KAPPA B/I KAPPA B SIGNAL TRANSDUCTION IN THE GENERATION AND TREATMENT OF HUMAN CANCER. THE REL/NF-KAPPA B FAMILY IS A GROUP OF STRUCTURALLY-RELATED, TIGHTLY-REGULATED TRANSCRIPTION FACTORS THAT CONTROL THE EXPRESSION OF A MULTITUDE OF GENES INVOLVED IN KEY CELLULAR AND ORGANISMAL PROCESSES. THE REL/NF-KAPPA B SIGNAL TRANSDUCTION PATHWAY IS MISREGULATED IN A VARIETY OF HUMAN CANCERS, ESPECIALLY ONES OF LYMPHOID CELL ORIGIN, DUE EITHER TO GENETIC CHANGES (SUCH AS CHROMOSOMAL REARRANGEMENTS, AMPLIFICATIONS, AND MUTATIONS) OR TO CHRONIC ACTIVATION OF THE PATHWAY BY EPIGENETIC MECHANISMS. CONSTITUTIVE ACTIVATION OF THE REL/NF-KAPPA B PATHWAY CAN CONTRIBUTE TO THE ONCOGENIC STATE IN SEVERAL WAYS, FOR EXAMPLE, BY DRIVING PROLIFERATION, BY ENHANCING CELL SURVIVAL, OR BY PROMOTING ANGIOGENESIS OR METASTASIS. IN MANY CASES, INHIBITION OF REL/NF-KAPPA B ACTIVITY REVERSES ALL OR PART OF THE MALIGNANT STATE. THUS, THE REL/NF-KAPPA B PATHWAY HAS RECEIVED MUCH ATTENTION AS A FOCAL POINT FOR CLINICAL INTERVENTION. 2002 7 3128 33 GIPC-REGULATED IGFBP-3 PROMOTES HSC MIGRATION IN VITRO AND PORTAL HYPERTENSION IN VIVO THROUGH A BETA1-INTEGRIN PATHWAY. BACKGROUND & AIMS: TRANSFORMING GROWTH FACTOR (TGF-BETA)-INDUCED ACTIVATION OF QUIESCENT HEPATIC STELLATE CELLS (HSCS) AND THEIR TRANSFORMATION TO MYOFIBROBLASTS IS A KEY EVENT IN LIVER FIBROSIS AND PORTAL HYPERTENSION. GIPC (ALSO REFERRED TO AS SYNECTIN) IS A DOWNSTREAM SIGNAL ACTIVATION MOLECULE OF TGF-BETA AND OTHER RECEPTORS. IN THIS STUDY, WE SOUGHT TO IDENTIFY NOVEL GENES TARGETED BY TGF-BETA AND GIPC AND ELUCIDATE IF AND HOW THEY MAY CONTRIBUTE TO LIVER FIBROSIS. METHODS: WE PERFORMED SEQUENTIAL MESSENGER RNA SEQUENCING ANALYSIS ON TGF-BETA-STIMULATED HSCS AND THEN ON TGF-BETA-STIMULATED HSCS IN THE PRESENCE AND ABSENCE OF GIPC ALSO REFERRED TO AS SYNECTIN (GIPC) KNOCKDOWN. INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-3 (IGFBP-3) TRANSPORT PROTEIN EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC. QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, TARGETED CHROMATIN IMMUNOPRECIPITATION, AND WESTERN BLOT ANALYSIS WERE DONE FOR FURTHER CONFIRMATION. RESULTS: IGFBP-3, AN INSULIN GROWTH FACTOR TRANSPORT PROTEIN, EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC, WHICH WAS CONFIRMED BY QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, AND WESTERN BLOT ANALYSIS. TARGETED CHROMATIN IMMUNOPRECIPITATION SHOWED THAT GIPC INCREASES THE HISTONE 3 LYSINE 27 (H3K27) ACETYLATION ACTIVATING MARK AND CONCURRENTLY DECREASES THE H3K27 INHIBITORY TRIMETHYLATION (H3K27M3) MARK, PROVIDING AN EPIGENETIC CORRELATE TO THE GENE REGULATION CHANGES. IN VIVO, GLOBAL KNOCKOUT OF IGFBP-3 MICE RESULTED IN ATTENUATION OF HSC ACTIVATION MARKERS AND ATTENUATION OF PORTAL PRESSURE IN RESPONSE TO CHRONIC LIVER INJURY MODELS. ANALYSIS OF SERUM LEVELS FROM CIRRHOTIC PATIENTS ALSO SHOWED AN IGFBP-3 INCREASE OF MORE THAN 2-FOLD COMPARED WITH HEALTHY CONTROLS. FINALLY, IN VITRO MECHANISM STUDIES SHOWED THAT IGFBP-3 PROMOTES HSC MIGRATION THROUGH INTEGRIN-DEPENDENT PHOSPHORYLATION OF PROTEIN KINASE B. CONCLUSIONS: TGF-BETA UP-REGULATES IGFBP-3 THROUGH GIPC, LEADING TO INCREASED HSC MIGRATION IN VITRO AND PROMOTES PORTAL HYPERTENSION IN VIVO. THESE STUDIES SUPPORT THE ROLE OF IGFBP-3 AS A POTENTIAL PATHOPHYSIOLOGIC TARGET OR BIOMARKER IN CHRONIC LIVER DISEASE. 2020 8 3049 24 GENOME-WIDE ANALYSIS REVEALS ZINC TRANSPORTER ZIP9 REGULATED BY DNA METHYLATION PROMOTES RADIATION-INDUCED SKIN FIBROSIS VIA THE TGF-BETA SIGNALING PATHWAY. RADIATION-INDUCED SKIN FIBROSIS IS A DETRIMENTAL AND CHRONIC DISORDER THAT OCCURS AFTER RADIATION EXPOSURE. DNA METHYLATION HAS BEEN CHARACTERIZED AS AN IMPORTANT REGULATORY MECHANISM OF MULTIPLE PATHOLOGICAL PROCESSES. IN THIS STUDY, WE COMPARED THE GENOME-WIDE DNA METHYLATION STATUS IN RADIATION-INDUCED FIBROTIC SKIN AND ADJACENT NORMAL TISSUES OF RATS BY METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING. RADIATION-INDUCED FIBROTIC SKIN SHOWED DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH 3,650 PROTEIN-CODING GENES, 72 MICRORNAS, 5,836 LONG NONCODING RNAS AND 3 PIWI-INTERACTING RNAS. BY INTEGRATING THE MRNA AND METHYLATION PROFILES, THE ZINC TRANSPORTER SLC39A9/ZIP9 WAS INVESTIGATED IN GREATER DETAIL. THE PROTEIN LEVEL OF ZIP9 WAS INCREASED IN IRRADIATED SKIN TISSUES OF HUMANS, MONKEYS, AND RATS, ESPECIALLY IN RADIOGENIC FIBROTIC SKIN TISSUES. RADIATION INDUCED THE DEMETHYLATION OF A CPG DINUCLEOTIDE IN EXON 1 OF ZIP9 THAT RESULTED IN RECRUITMENT OF THE TRANSCRIPTIONAL FACTOR SP1 AND INCREASED ZIP9 EXPRESSION. OVEREXPRESSION OF ZIP9 RESULTED IN ACTIVATION OF THE PROFIBROTIC TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY THROUGH PROTEIN KINASE B IN HUMAN FIBROBLASTS. IN ADDITION, RADIATION-INDUCED SKIN FIBROSIS WAS ASSOCIATED WITH INCREASED ZINC ACCUMULATION. THE ZINC CHELATOR N,N,N',N'-TETRAKIS(2-PYRIDYLMETHYL)-1,2-ETHYLENEDIAMINE ABROGATED ZIP9-INDUCED ACTIVATION OF THE TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY AND ATTENUATED RADIATION-INDUCED SKIN FIBROSIS IN A RAT MODEL. IN SUMMARY, OUR FINDINGS ILLUSTRATE EPIGENETIC REGULATION OF ZIP9 AND ITS CRITICAL ROLE IN PROMOTING RADIATION-INDUCED SKIN FIBROSIS. 2020 9 3327 32 HISTONE DEACETYLASE 4 PROMOTES CHOLESTATIC LIVER INJURY IN THE ABSENCE OF PROHIBITIN-1. PROHIBITIN-1 (PHB1) IS AN EVOLUTIONARILY CONSERVED PLEIOTROPIC PROTEIN THAT PARTICIPATES IN DIVERSE PROCESSES DEPENDING ON ITS SUBCELLULAR LOCALIZATION AND INTERACTOME. RECENT DATA HAVE INDICATED A DIVERSE ROLE FOR PHB1 IN THE PATHOGENESIS OF OBESITY, CANCER, AND INFLAMMATORY BOWEL DISEASE, AMONG OTHERS. DATA PRESENTED HERE SUGGEST THAT PHB1 IS ALSO LINKED TO CHOLESTATIC LIVER DISEASE. EXPRESSION OF PHB1 IS MARKEDLY REDUCED IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS AND BILIARY ATRESIA OR WITH ALAGILLE SYNDROME, TWO MAJOR PEDIATRIC CHOLESTATIC CONDITIONS. IN THE EXPERIMENTAL MODEL OF BILE DUCT LIGATION, SILENCING OF PHB1 INDUCED LIVER FIBROSIS, REDUCED ANIMAL SURVIVAL, AND INDUCED BILE DUCT PROLIFERATION. IMPORTANTLY, THE MODULATORY EFFECT OF PHB1 IS NOT DEPENDENT ON ITS KNOWN MITOCHONDRIAL FUNCTION. ALSO, PHB1 INTERACTS WITH HISTONE DEACETYLASE 4 (HDAC4) IN THE PRESENCE OF BILE ACIDS. HENCE, PHB1 DEPLETION LEADS TO INCREASED NUCLEAR HDAC4 CONTENT AND ITS ASSOCIATED EPIGENETIC CHANGES. REMARKABLY, HDAC4 SILENCING AND THE ADMINISTRATION OF THE HDAC INHIBITOR PARTHENOLIDE DURING OBSTRUCTIVE CHOLESTASIS IN VIVO PROMOTE GENOMIC REPROGRAMMING, LEADING TO REGRESSION OF THE FIBROTIC PHENOTYPE IN LIVER-SPECIFIC PHB1 KNOCKOUT MICE. CONCLUSION: PHB1 IS AN IMPORTANT MEDIATOR OF CHOLESTATIC LIVER INJURY THAT REGULATES THE ACTIVITY OF HDAC4, WHICH CONTROLS SPECIFIC EPIGENETIC MARKERS; THESE RESULTS IDENTIFY POTENTIAL NOVEL STRATEGIES TO TREAT LIVER INJURY AND FIBROSIS, PARTICULARLY AS A CONSEQUENCE OF CHRONIC CHOLESTASIS. 2015 10 1806 32 EFFECT OF TRANSCRIPTION INHIBITION AND GENERATION OF SUPPRESSIVE VIRAL NON-CODING RNAS. BACKGROUND: HIV-1 PATIENTS RECEIVING COMBINATION ANTIRETROVIRAL THERAPY (CART) SURVIVE INFECTION BUT REQUIRE LIFE-LONG ADHERENCE AT HIGH EXPENSE. IN CHRONIC CART-TREATED PATIENTS WITH UNDETECTABLE VIRAL TITERS, CELL-ASSOCIATED VIRAL RNA IS STILL DETECTABLE, POINTING TO LOW-LEVEL VIRAL TRANSCRIPTIONAL LEAKINESS. TO DATE, THERE ARE NO FDA-APPROVED DRUGS AGAINST HIV-1 TRANSCRIPTION. WE HAVE PREVIOUSLY SHOWN THAT F07#13, A THIRD GENERATION TAT PEPTIDE MIMETIC WITH COMPETITIVE ACTIVITY AGAINST CDK9/T1-TAT BINDING SITES, INHIBITS HIV-1 TRANSCRIPTION IN VITRO AND IN VIVO. RESULTS: HERE, WE DEMONSTRATE THAT INCREASING CONCENTRATIONS OF F07#13 (0.01, 0.1, 1 MICROM) CAUSE A DECREASE IN TAT LEVELS IN A DOSE-DEPENDENT MANNER BY INHIBITING THE CDK9/T1-TAT COMPLEX FORMATION AND SUBSEQUENT UBIQUITIN-MEDIATED TAT SEQUESTRATION AND DEGRADATION. OUR DATA INDICATE THAT COMPLEXES I AND IV CONTAIN DISTINCT PATTERNS OF UBIQUITINATED TAT AND THAT TRANSCRIPTIONAL INHIBITION INDUCED BY F07#13 CAUSES AN OVERALL REDUCTION IN TAT LEVELS. THIS REDUCTION MAY BE TRIGGERED BY F07#13 BUT ULTIMATELY IS MEDIATED BY TAR-GAG VIRAL RNAS THAT BIND SUPPRESSIVE TRANSCRIPTION FACTORS (SIMILAR TO 7SK, NRON, HOTAIR, AND XIST LNCRNAS) TO ENHANCE TRANSCRIPTIONAL GENE SILENCING AND LATENCY. THESE RNAS COMPLEX WITH PRC2, SIN3A, AND CUL4B, RESULTING IN EPIGENETIC MODIFICATIONS. FINALLY, WE OBSERVED AN F07#13-MEDIATED DECREASE OF VIRAL BURDEN BY TARGETING THE R REGION OF THE LONG TERMINAL REPEAT (HIV-1 PROMOTER REGION, LTR), PROMOTING BOTH PAUSED POLYMERASES AND INCREASED EFFICIENCY OF CRISPR/CAS9 EDITING IN INFECTED CELLS. THIS IMPLIES THAT GENE EDITING MAY BE BEST PERFORMED UNDER A REPRESSED TRANSCRIPTIONAL STATE. CONCLUSIONS: COLLECTIVELY, OUR RESULTS INDICATE THAT F07#13, WHICH CAN TERMINATE RNA POLYMERASE II AT DISTINCT SITES, CAN GENERATE SCAFFOLD RNAS, WHICH MAY ASSEMBLE INTO SPECIFIC SETS OF "RNA MACHINES" THAT CONTRIBUTE TO GENE REGULATION. IT REMAINS TO BE SEEN WHETHER THESE EFFECTS CAN ALSO BE SEEN IN VARIOUS CLADES THAT HAVE VARYING PROMOTER STRENGTH, MUTANT LTRS, AND IN PATIENT SAMPLES. 2019 11 5153 29 PPP2R2B HYPERMETHYLATION CAUSES ACQUIRED APOPTOSIS DEFICIENCY IN SYSTEMIC AUTOIMMUNE DISEASES. CHRONIC INFLAMMATION CAUSES TARGET ORGAN DAMAGE IN PATIENTS WITH SYSTEMIC AUTOIMMUNE DISEASES. THE FACTORS THAT ALLOW THIS PROTRACTED RESPONSE ARE POORLY UNDERSTOOD. WE ANALYZED THE TRANSCRIPTIONAL REGULATION OF PPP2R2B (B55SS), A MOLECULE NECESSARY FOR THE TERMINATION OF THE IMMUNE RESPONSE, IN PATIENTS WITH AUTOIMMUNE DISEASES. ALTERED EXPRESSION OF B55SS CONDITIONED RESISTANCE TO CYTOKINE WITHDRAWAL-INDUCED DEATH (CWID) IN PATIENTS WITH AUTOIMMUNE DISEASES. THE IMPAIRED UPREGULATION OF B55SS WAS CAUSED BY INFLAMMATION-DRIVEN HYPERMETHYLATION OF SPECIFIC CYTOSINES LOCATED WITHIN A REGULATORY ELEMENT OF PPP2R2B PREVENTING CTCF BINDING. THIS PHENOTYPE COULD BE INDUCED IN HEALTHY T CELLS BY EXPOSURE TO TNF-ALPHA. OUR RESULTS REVEAL A GENE WHOSE EXPRESSION IS AFFECTED BY AN ACQUIRED DEFECT, THROUGH AN EPIGENETIC MECHANISM, IN THE SETTING OF SYSTEMIC AUTOIMMUNITY. BECAUSE FAILURE TO REMOVE ACTIVATED T CELLS THROUGH CWID COULD CONTRIBUTE TO AUTOIMMUNE PATHOLOGY, THIS MECHANISM ILLUSTRATES A VICIOUS CYCLE THROUGH WHICH AUTOIMMUNE INFLAMMATION CONTRIBUTES TO ITS OWN PERPETUATION. 2019 12 2432 33 EPIGENETIC SILENCING OF MIR-708 ENHANCES NF-KAPPAB SIGNALING IN CHRONIC LYMPHOCYTIC LEUKEMIA. MICRORNAS (MIRNAS) ARE POST-TRANSCRIPTIONAL REGULATORS OF GENE EXPRESSION AND THEIR DEREGULATION IS INVOLVED IN TUMOR DEVELOPMENT. EPIGENETIC GENE SILENCING IN CANCER BY DNA METHYLATION CONTRIBUTES TO THE SILENCING OF TUMOR-SUPPRESSOR GENES, INCLUDING MIRNAS. WE HAVE RECENTLY SHOWN THAT THE PROMOTER OF MIR-708 IS ABERRANTLY METHYLATED IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). TO CHARACTERIZE THE MOLECULAR SIGNALING NETWORKS THAT ARE INFLUENCED BY MIR-708, WE PERFORMED A LUCIFERASE-BASED SCREEN EVALUATING THE EFFECTS OF ECTOPIC MIR-708 EXPRESSION ON LEUKEMIA-RELEVANT SIGNALING PATHWAYS. WE FOUND THAT MIR-708 STRONGLY REPRESSED NF-KAPPAB SIGNALING, A PATHWAY KNOWN TO BE DEREGULATED IN CLL. AMONG THE PREDICTED MIR-708 TARGETS WAS IKKBETA (INHIBITOR OF KAPPA LIGHT POLYPEPTIDE GENE ENHANCER IN B CELLS, KINASE-BETA/IKBKB), A KEY KINASE FACILITATING NF-KAPPAB SIGNALING. WE VALIDATED THE INTERACTION OF MIR-708 WITH THE 3'-UNTRANSLATED REGION OF IKKBETA AND FOUND THAT MIR-708 OVEREXPRESSION REPRESSES ENDOGENOUS IKKBETA. PHOSPHORYLATION OF THE IKKBETA TARGET IKAPPABALPHA AND EXPRESSION OF KNOWN NF-KAPPAB TARGET GENES WERE IMPAIRED BY MIR-708. FURTHERMORE, WE IDENTIFIED AN ENHANCER REGION DOWNSTREAM OF THE MIR-708 PROMOTER THAT DISPLAYS A DISTINCT DNA METHYLATION STATUS IN CLL. HIGH ENHANCER METHYLATION IS SIGNIFICANTLY CORRELATED WITH LOWER MIR-708 EXPRESSION AND IS PREDOMINANTLY FOUND IN PATIENTS WITH POOR PROGNOSIS AND SHORTER TIME TO TREATMENT. THESE RESULTS DEMONSTRATE THAT MIR-708 REGULATES THE NF-KAPPAB PATHWAY BY TARGETING IKKBETA, AND THAT METHYLATION OF A KEY ENHANCER REGION CONTRIBUTES TO ITS SUPPRESSION IN CLL. 2015 13 1966 32 EPIGENETIC ALTERATION OF PRKCDBP IN COLORECTAL CANCERS AND ITS IMPLICATION IN TUMOR CELL RESISTANCE TO TNFALPHA-INDUCED APOPTOSIS. PURPOSE: PRKCDBP IS A PUTATIVE TUMOR SUPPRESSOR IN WHICH ALTERATION HAS BEEN OBSERVED IN SEVERAL HUMAN CANCERS. WE INVESTIGATED EXPRESSION AND FUNCTION OF PRKCDBP IN COLORECTAL CELLS AND TISSUES TO EXPLORE ITS CANDIDACY AS A SUPPRESSOR IN COLORECTAL TUMORIGENESIS. EXPERIMENTAL DESIGN: EXPRESSION AND METHYLATION STATUS OF PRKCDBP AND ITS EFFECT ON TUMOR GROWTH WERE EVALUATED. TRANSCRIPTIONAL REGULATION BY NF-KAPPAB SIGNALING WAS DEFINED BY LUCIFERASE REPORTER AND CHROMATIN IMMUNOPRECIPITATION ASSAYS. RESULTS: PRKCDBP EXPRESSION WAS HARDLY DETECTABLE IN 29 OF 80 (36%) PRIMARY TUMORS AND 11 OF 19 (58%) CELL LINES, AND ITS ALTERATION CORRELATED WITH TUMOR STAGE AND GRADE. PROMOTER HYPERMETHYLATION WAS COMMONLY FOUND IN CANCERS. PRKCDBP EXPRESSION INDUCED THE G(1) CELL-CYCLE ARREST AND INCREASED CELLULAR SENSITIVITY TO VARIOUS APOPTOTIC STRESSES. PRKCDBP WAS INDUCED BY TNFALPHA, AND ITS LEVEL CORRELATED WITH TUMOR CELL SENSITIVITY TO TNFALPHA-INDUCED APOPTOSIS. PRKCDBP INDUCTION BY TNFALPHA WAS DISRUPTED BY BLOCKING NF-KAPPAB SIGNALING WHILE IT WAS ENHANCED BY RELA TRANSFECTION. THE PRKCDBP PROMOTER ACTIVITY WAS INCREASED IN RESPONSE TO TNFALPHA, AND THIS RESPONSE WAS ABOLISHED BY DISRUPTION OF A KAPPAB SITE IN THE PROMOTER. PRKCDBP DELAYED THE FORMATION AND GROWTH OF XENOGRAFT TUMORS AND IMPROVED TUMOR RESPONSE TO TNFALPHA-INDUCED APOPTOSIS. CONCLUSIONS: PRKCDBP IS A PROAPOPTOTIC TUMOR SUPPRESSOR WHICH IS COMMONLY ALTERED IN COLORECTAL CANCER BY PROMOTER HYPERMETHYLATION, AND ITS GENE TRANSCRIPTION IS DIRECTLY ACTIVATED BY NF-KAPPAB IN RESPONSE TO TNFALPHA. THIS SUGGESTS THAT PRKCDBP INACTIVATION MAY CONTRIBUTE TO TUMOR PROGRESSION BY REDUCING CELLULAR SENSITIVITY TO TNFALPHA AND OTHER STRESSES, PARTICULARLY UNDER CHRONIC INFLAMMATORY MICROENVIRONMENT. 2011 14 4545 36 MUTANT P53 GAIN OF FUNCTION AND CHEMORESISTANCE: THE ROLE OF MUTANT P53 IN RESPONSE TO CLINICAL CHEMOTHERAPY. PURPOSE: TO REVIEW MECHANISMS UNDERLYING MUTANT P53 (MUTP53) GAIN OF FUNCTION (GOF) AND MUTP53-INDUCED CHEMORESISTANCE, AND TO INVESTIGATE THE ROLE OF MUTP53 IN RESPONSE TO CLINICAL CHEMOTHERAPY. METHODS: WE SEARCHED THE PUBMED DATABASE FOR CLINICAL STUDIES FROM THE PAST DECADE, INCLUDING DATA EVALUATING THE IMPACT OF MUTP53 IN CLINICAL CHEMOTHERAPY RESPONSE. RESULTS: INTERACTIONS BETWEEN MUTP53 AND TRANSCRIPTIONAL FACTORS, PROTEINS OR DNA STRUCTURES, AS WELL AS EPIGENETIC REGULATION, CONTRIBUTE TO MUTP53 GOF. MAJOR MECHANISMS OF MUTP53-INDUCED CHEMORESISTANCE INCLUDE ENHANCED DRUG EFFLUX AND METABOLISM, PROMOTING SURVIVAL, INHIBITING APOPTOSIS, UPREGULATING DNA REPAIR, SUPPRESSING AUTOPHAGY, ELEVATING MICROENVIRONMENTAL RESISTANCE AND INDUCING A STEM-LIKE PHENOTYPE. CLINICALLY, MUTP53 PREDICTED RESISTANCE TO CHEMOTHERAPY IN DIFFUSE LARGE B-CELL LYMPHOMA, AND ESOPHAGEAL AND OROPHARYNGEAL CANCERS, BUT ITS IMPACT ON CHRONIC LYMPHOCYTIC LEUKEMIA WAS UNCLEAR. IN BLADDER CANCER, MUTP53 DID NOT PREDICT RESISTANCE, WHEREAS IN SOME BREAST AND OVARIAN CANCERS, IT WAS ASSOCIATED WITH SENSITIVITY TO CERTAIN CHEMOTHERAPEUTIC AGENTS. CONCLUSION: MUTP53 HAS AN INTRICATE ROLE IN THE RESPONSE TO CLINICAL CHEMOTHERAPY AND SHOULD NOT BE INTERPRETED IN ISOLATION. FURTHERMORE, WHEN PREDICTING TUMOR RESPONSE TO CHEMOTHERAPY BASED ON THE P53 STATUS, THE DRUGS USED SHOULD ALSO BE TAKEN INTO CONSIDERATION. THESE CONCEPTS REQUIRE FURTHER INVESTIGATION. 2017 15 1461 33 DISRUPTION OF RCAN1.4 EXPRESSION MEDIATED BY YY1/HDAC2 MODULATES CHRONIC RENAL ALLOGRAFT INTERSTITIAL FIBROSIS. CHRONIC ALLOGRAFT DYSFUNCTION (CAD) IS A MAJOR FACTOR THAT HINDERS KIDNEY TRANSPLANT SURVIVAL IN THE LONG RUN. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) HAS BEEN CONFIRMED TO SIGNIFICANTLY CONTRIBUTE TO INTERSTITIAL FIBROSIS/TUBULAR ATROPHY (IF/TA), WHICH IS THE MAIN HISTOPATHOLOGICAL FEATURE OF CAD. ABERRANT EXPRESSION OF THE REGULATOR OF CALCINEURIN 1 (RCAN1), RECOGNIZED AS AN ENDOGENOUS INHIBITOR OF THE CALCINEURIN PHOSPHATASE, HAS BEEN SHOWN TO BE EXTENSIVELY INVOLVED IN VARIOUS KIDNEY DISEASES. HOWEVER, IT REMAINS UNCLEAR HOW RCAN1.4 REGULATES IF/TA FORMATION IN CAD PATIENTS. HEREIN, AN IN VIVO MOUSE RENAL TRANSPLANTATION MODEL AND AN IN VITRO MODEL OF HUMAN RENAL TUBULAR EPITHELIAL CELLS (HK-2) TREATED WITH TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) WERE EMPLOYED. OUR RESULTS PROVED THAT RCAN1.4 EXPRESSION WAS DECREASED IN VIVO AND IN VITRO, IN ADDITION TO THE UP-REGULATION OF YIN YANG 1 (YY1), A TRANSCRIPTION FACTOR THAT HAS BEEN REPORTED TO CONVEY MULTIPLE FUNCTIONS IN CHRONIC KIDNEY DISEASE (CKD). KNOCKING IN OF RCAN1.4 EFFICIENTLY ATTENUATED CHRONIC RENAL ALLOGRAFT INTERSTITIAL FIBROSIS IN VIVO AND INHIBITED TNF-ALPHA-INDUCED EMT IN VITRO THROUGH REGULATING ANTI-OXIDATIVE STRESS AND THE CALCINEURIN/NUCLEAR FACTOR OF ACTIVATED T CELLS CYTOPLASMIC 1 (NFATC1) SIGNALING PATHWAY. IN ADDITION, SUPPRESSION OF YY1 MEDIATED BY SHRNA OR SIRNA ALLEVIATED TNF-ALPHA-INDUCED EMT THROUGH ABOLISHING REACTIVE SPECIES PARTLY IN AN RCAN1.4-DEPENDENT MANNER. NOTABLY, WE CONFIRMED THAT YY1 NEGATIVELY REGULATED RCAN1.4 TRANSCRIPTION BY DIRECTLY INTERACTING WITH THE RCAN1.4 PROMOTER. IN ADDITION, HISTONE DEACETYLASE 2 (HDAC2) INTERACTED WITH YY1 TO FORM A MULTI-MOLECULAR COMPLEX, WHICH WAS INVOLVED IN TNF-ALPHA-INDUCED RCAN1.4 TRANSCRIPTIONAL REPRESSION. THEREFORE, RCAN1.4 IS SUGGESTED TO BE MODULATED BY THE YY1/HDAC2 TRANSCRIPTION REPRESSOR COMPLEX IN AN EPIGENETIC MANNER, WHICH IS A MEDIATED NEPHROPROTECTIVE EFFECT PARTLY THROUGH MODULATING O2?- GENERATION AND THE CALCINEURIN/NFATC1 SIGNALING PATHWAY. THUS, THE YY1-RCAN1.4 AXIS CONSTITUTES AN INNOVATIVE TARGET FOR IF/TA TREATMENT IN CAD PATIENTS. 2023 16 3718 29 INHIBITION OF BCL6B PROMOTES GASTRIC CANCER BY AMPLIFYING INFLAMMATION IN MICE. BACKGROUND: CHRONIC GASTRITIS HAS BEEN DEMONSTRATED TO BE A KEY CAUSE OF GASTRIC CANCER (GC), AND CONTROL OF GASTRIC INFLAMMATION IS REGARDED AS AN EFFECTIVE TREATMENT FOR THE CLINICAL PREVENTION OF GASTRIC CARCINOGENESIS. HOWEVER, THERE REMAINS AN UNMET NEED TO IDENTIFY THE DOMINANT REGULATORS OF GASTRIC ONCOGENESIS-ASSOCIATED INFLAMMATION IN VIVO. METHODS: THE MOUSE MODEL FOR THE STUDY OF INFLAMMATION-ASSOCIATED GC WAS INDUCED BY BENZO[A]PYRENE (BAP) INTRAGASTRIC ADMINISTRATION IN BCL6B(-/-) AND WILDTYPE MICE ON A C57BL/6 BACKGROUND. 5-AZA-2'-DEOXYCYTIDINE (5-AZA), THE DEMETHYLATION DRUG, WAS INTRAPERITONEALLY INJECTED TO RESTORE BCL6B EXPRESSION. HUMAN GC TISSUE ARRAY WAS USED TO ANALYSE PATIENT SURVIVAL BASED ON BCL6B AND CD3 PROTEIN EXPRESSION. RESULTS: BCL6B WAS GRADUALLY DOWNREGULATED BY ITS OWN PROMOTER HYPERMETHYLATION IN PARALLEL TO AN INCREASING INFLAMMATORY RESPONSE DURING THE PROGRESSION OF BAP-INDUCED GASTRIC CARCINOGENESIS IN MICE. MOREOVER, KNOCKOUT OF BCL6B DRAMATICALLY WORSENED THE SEVERITY OF GASTRIC CANCER AND AGGRAVATED THE INFLAMMATORY RESPONSE IN THE BAP-INDUCED MICE GC MODEL. RE-ACTIVATION OF BCL6B BY 5-AZA IMPEDED INFLAMMATORY AMPLIFICATION AND BAP-INDUCED GC DEVELOPMENT, PROLONGING SURVIVAL TIME IN WILDTYPE MICE, WHEREAS NO NOTABLE CURATIVE EFFECT OCCURRED IN BCL6B(-/-) MICE WITH 5-AZA TREATMENT. FINALLY, SIGNIFICANT NEGATIVE CORRELATIONS WERE DETECTED BETWEEN THE MRNA LEVELS OF BCL6B AND INFLAMMATORY CYTOKINES IN HUMAN GC TISSUES; PATIENTS HARBOURING BCL6B-NEGETIVE AND SEVERE-INFLAMMATION GC TUMOURS WERE FOUND TO EXHIBIT THE SHORTEST SURVIVAL TIME. CONCLUSIONS: EPIGENETIC INACTIVATION OF BCL6B PROMOTES GASTRIC CANCER THROUGH AMPLIFICATION OF THE GASTRIC INFLAMMATORY RESPONSE IN VIVO AND OFFERS A NEW APPROACH FOR GC TREATMENT AND REGENERATIVE MEDICINE. 2019 17 2758 29 EXPRESSION OF HORMONAL CARCINOGENESIS GENES AND RELATED REGULATORY MICRORNAS IN UTERUS AND OVARIES OF DDT-TREATED FEMALE RATS. THE INSECTICIDE DICHLORODIPHENYLTRICHLOROETHANE (DDT) IS A NONMUTAGENIC XENOBIOTIC COMPOUND ABLE TO EXERT ESTROGEN-LIKE EFFECTS RESULTING IN ACTIVATION OF ESTROGEN RECEPTOR-ALPHA (ERALPHA) FOLLOWED BY CHANGED EXPRESSION OF ITS DOWNSTREAM TARGET GENES. IN ADDITION, STUDIES PERFORMED OVER RECENT YEARS SUGGEST THAT DDT MAY ALSO INFLUENCE EXPRESSION OF MICRORNAS. HOWEVER, AN IMPACT OF DDT ON EXPRESSION OF ER, MICRORNAS, AND RELATED TARGET GENES HAS NOT BEEN FULLY ELUCIDATED. HERE, USING REAL-TIME PCR, WE ASSESSED CHANGES IN EXPRESSION OF KEY GENES INVOLVED IN HORMONAL CARCINOGENESIS AS WELL AS POTENTIALLY RELATED REGULATORY ONCOGENIC/TUMOR SUPPRESSOR MICRORNAS AND THEIR TARGET GENES IN THE UTERUS AND OVARIES OF FEMALE WISTAR RATS DURING SINGLE AND CHRONIC MULTIPLE-DOSE DDT EXPOSURE. WE FOUND THAT APPLYING DDT RESULTS IN ALTERED EXPRESSION OF MICRORNAS-221, -222, -205, -126A, AND -429, THEIR TARGET GENES (PTEN, DICER1), AS WELL AS GENES INVOLVED IN HORMONAL CARCINOGENESIS (ESR1, PGR, CCND1, CYP19A1). NOTABLY, CYP19A1 EXPRESSION SEEMS TO BE ALSO REGULATED BY MICRORNAS-221, -222, AND -205. THE DATA SUGGEST THAT EPIGENETIC EFFECTS INDUCED BY DDT AS A POTENTIAL CARCINOGEN MAY BE BASED ON AT LEAST TWO MECHANISMS: (I) ACTIVATION OF ERALPHA FOLLOWED BY ALTERED EXPRESSION OF THE TARGET GENES ENCODING RECEPTOR PGR AND CCND1 AS WELL AS IMPAIRED EXPRESSION OF CYP19A1, AFFECTING, THEREBY, CELL HORMONE BALANCE; AND (II) CHANGED EXPRESSION OF MICRORNAS RESULTING IN IMPAIRED EXPRESSION OF RELATED TARGET GENES INCLUDING REDUCED LEVEL OF CYP19A1 MRNA. 2017 18 1335 32 DERMAL FIBROBLASTS CULTURED FROM DONORS WITH TYPE 2 DIABETES MELLITUS RETAIN AN EPIGENETIC MEMORY ASSOCIATED WITH POOR WOUND HEALING RESPONSES. THE PREVALENCE OF TYPE 2 DIABETES MELLITUS (T2DM) IS ESCALATING GLOBALLY. PATIENTS SUFFER FROM MULTIPLE COMPLICATIONS INCLUDING THE DEVELOPMENT OF CHRONIC WOUNDS THAT CAN LEAD TO AMPUTATION. THESE WOUNDS ARE CHARACTERISED BY AN INFLAMMATORY ENVIRONMENT INCLUDING ELEVATED TUMOUR NECROSIS FACTOR ALPHA (TNF-ALPHA). DERMAL FIBROBLASTS (DF) ARE CRITICAL FOR EFFECTIVE WOUND HEALING, SO WE SOUGHT TO ESTABLISH WHETHER THERE WERE ANY DIFFERENCES IN DF CULTURED FROM T2DM DONORS OR THOSE WITHOUT DIABETES (ND-DF). ND- AND T2DM-DF WHEN CULTURED SIMILARLY IN VITRO SECRETED COMPARABLE CONCENTRATIONS OF TNF-ALPHA. FUNCTIONALLY, PRE-TREATMENT WITH TNF-ALPHA REDUCED THE PROLIFERATION OF ND-DF AND TRANSIENTLY ALTERED ND-DF MORPHOLOGY; HOWEVER, T2DM-DF WERE RESISTANT TO THESE TNF-ALPHA INDUCED CHANGES. IN CONTRAST, TNF-ALPHA INHIBITED ND- AND T2DM-DF MIGRATION AND MATRIX METALLOPROTEASE EXPRESSION TO THE SAME DEGREE, ALTHOUGH T2DM-DF EXPRESSED SIGNIFICANTLY HIGHER LEVELS OF TISSUE INHIBITOR OF METALLOPROTEASES (TIMP)-2. FINALLY, TNF-ALPHA SIGNIFICANTLY INCREASED THE SECRETION OF PRO-INFLAMMATORY CYTOKINES (INCLUDING CCL2, CXCL1 AND SERPINE1) IN ND-DF, WHILST THIS EFFECT IN T2DM-DF WAS BLUNTED, PRESUMABLY DUE TO THE TENDENCY TO HIGHER BASELINE PRO-INFLAMMATORY CYTOKINE EXPRESSION OBSERVED IN THIS CELL TYPE. COLLECTIVELY, THESE DATA DEMONSTRATE THAT T2DM-DF EXHIBIT A SELECTIVE LOSS OF RESPONSIVENESS TO TNF-ALPHA, PARTICULARLY REGARDING PROLIFERATIVE AND SECRETORY FUNCTIONS. THIS HIGHLIGHTS IMPORTANT PHENOTYPIC CHANGES IN T2DM-DF THAT MAY EXPLAIN THE SUSCEPTIBILITY TO CHRONIC WOUNDS IN THESE PATIENTS. 2021 19 2763 24 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS. 2010 20 5636 35 SERELAXIN ALLEVIATES CARDIAC FIBROSIS THROUGH INHIBITING ENDOTHELIAL-TO-MESENCHYMAL TRANSITION VIA RXFP1. RATIONALE: CARDIAC FIBROSIS IS AN INTEGRAL CONSTITUENT OF EVERY FORM OF CHRONIC HEART DISEASE, AND PERSISTENCE OF FIBROSIS REDUCES TISSUE COMPLIANCE AND ACCELERATES THE PROGRESSION TO HEART FAILURE. RELAXIN-2 IS A HUMAN HORMONE, WHICH HAS VARIOUS PHYSIOLOGICAL FUNCTIONS SUCH AS MEDIATING RENAL VASODILATION IN PREGNANCY. ITS RECOMBINANT FORM SERELAXIN HAS RECENTLY BEEN TESTED IN CLINICAL TRIALS AS A THERAPY FOR ACUTE HEART FAILURE BUT DID NOT MEET ITS PRIMARY ENDPOINTS. THE AIM OF THIS STUDY IS TO EXAMINE WHETHER SERELAXIN HAS AN ANTI-FIBROTIC EFFECT IN THE HEART AND THEREFORE COULD BE BENEFICIAL IN CHRONIC HEART FAILURE. METHODS: WE UTILIZED TWO DIFFERENT CARDIAC FIBROSIS MOUSE MODELS (ASCENDING AORTIC CONSTRICTION (AAC) AND ANGIOTENSIN II (ATII) ADMINISTRATION VIA OSMOTIC MINIPUMPS) TO ASSESS THE ANTI-FIBROTIC POTENTIAL OF SERELAXIN. HISTOLOGICAL ANALYSIS, IMMUNOFLUORESCENCE STAINING AND MOLECULAR ANALYSIS WERE PERFORMED TO ASSESS THE FIBROSIS LEVEL AND INDICATE ENDOTHELIAL CELLS WHICH ARE UNDERGOING ENDMT. IN VITRO TGFBETA1-INDUCED ENDOTHELIAL-TO-MESENCHYMAL TRANSITION (ENDMT) ASSAYS WERE PERFORMED IN HUMAN CORONARY ARTERY ENDOTHELIAL CELLS AND MOUSE CARDIAC ENDOTHELIAL CELLS (MCECS) AND WERE EXAMINED USING MOLECULAR METHODS. CHROMATIN IMMUNOPRECIPITATION-QPCR ASSAY WAS UTILIZED TO IDENTIFY THE SERELAXIN EFFECT ON CHROMATIN REMODELING IN THE RXFP1 PROMOTER REGION IN MCECS. RESULTS: OUR RESULTS DEMONSTRATE A SIGNIFICANT AND DOSE-DEPENDENT ANTI-FIBROTIC EFFECT OF SERELAXIN IN THE HEART IN BOTH MODELS. WE FURTHER SHOW THAT SERELAXIN MEDIATES THIS EFFECT, AT LEAST IN PART, THROUGH INHIBITION OF ENDMT THROUGH THE ENDOTHELIAL RELAXIN FAMILY PEPTIDE RECEPTOR 1 (RXFP1). WE FURTHER DEMONSTRATE THAT SERELAXIN ADMINISTRATION IS ABLE TO INCREASE ITS OWN RECEPTOR EXPRESSION (RXFP1) THROUGH EPIGENETIC REGULATION IN FORM OF HISTONE MODIFICATIONS BY ATTENUATING TGFBETA-PSMAD2/3 SIGNALING IN ENDOTHELIAL CELLS. CONCLUSIONS: THIS STUDY IS THE FIRST TO IDENTIFY THAT SERELAXIN INCREASES THE EXPRESSION OF ITS OWN RECEPTOR RXFP1 AND THAT THIS MEDIATES THE INHIBITION OF ENDMT AND CARDIAC FIBROSIS, SUGGESTING THAT SERELAXIN MAY HAVE A BENEFICIAL EFFECT AS ANTI-FIBROTIC THERAPY IN CHRONIC HEART FAILURE. 2020