1 5795 104 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 2 598 25 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 3 2380 31 EPIGENETIC REGULATION OF WNT SIGNALING IN CHRONIC LYMPHOCYTIC LEUKEMIA. CERTAIN WNT AND WNT NETWORK TARGET GENES ARE EXPRESSED AT HIGHER OR LOWER LEVELS IN CHRONIC LYMPHOCYTIC LEUKEMIA COMPARED WITH NORMAL B-CELLS. THIS INCLUDES UPREGULATION OF NUCLEAR COMPLEX GENES, AS WELL AS GENES FOR CYTOPLASMIC PROTEINS AND WNT LIGANDS AND THEIR COGNATE RECEPTORS. IN ADDITION, EPIGENETIC SILENCING OF SEVERAL NEGATIVE REGULATORS OF THE WNT PATHWAY HAVE BEEN IDENTIFIED. THE BALANCE BETWEEN EPIGENETIC DOWNREGULATION OF NEGATIVE EFFECTOR GENES AND INCREASED EXPRESSION OF POSITIVE EFFECTOR GENES DEMONSTRATE THAT THE EPIGENETIC DOWNREGULATION OF WNT ANTAGONISTS IS ONE MECHANISM, PERHAPS THE MAIN MECHANISM, THAT IS PERMISSIVE TO ACTIVE WNT SIGNALING IN CHRONIC LYMPHOCYTIC LEUKEMIA. MOREOVER, CONSTITUTIVE ACTIVATION OF THE WNT NETWORK AND TARGET GENES IS LIKELY TO IMPACT ON ADDITIONAL INTERACTING SIGNALING PATHWAYS. BASED ON PUBLISHED STUDIES, WE PROPOSE A MODEL OF WNT SIGNALING THAT INVOLVES MAINLY PERMISSIVE EXPRESSION, AND SOMETIMES OVEREXPRESSION, OF POSITIVE EFFECTORS AND DOWNREGULATION OF NEGATIVE REGULATORS IN THE NETWORK. IN THIS MODEL, DNA METHYLATION, HISTONE MODIFICATIONS AND ALTERED EXPRESSION OF MICRORNA MOLECULES INTERACT TO ALLOW CONTINUOUS WNT SIGNALING. 2010 4 6910 20 [TRANSFORMING GROWTH FACTOR-BETA AND RENAL FIBROSIS]. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS A DRIVING FORCE OF RENAL FIBROSIS, WHICH MAY LEAD TO CHRONIC KIDNEY DISEASES AND EVEN END STAGE RENAL DISEASES. BY ACTIVATING CANONICAL AND NON-CANONICAL SIGNALING PATHWAYS, TGF-BETA PROMOTES THE SYNTHESIS OF EXTRACELLULAR MATRIX WHILE PREVENTING THEIR DEGRADATION. IN THE INJURED KIDNEY, TGF-BETA INDUCES APOPTOSIS, PROLIFERATION AND FIBROTIC RESPONSE OF RENAL CELLS INCLUDING EPITHELIAL CELLS, ENDOTHELIAL CELLS, PODOCYTES, FIBROBLASTS, PERICYTES AND MACROPHAGES, AND IT ALSO PROMOTES TRANSDIFFERENTIATION, ACTIVATION AND PROLIFERATION OF MYOFIBROBLASTS. ADDITIONALLY, TGF-BETA EXERTS PROFIBROTIC EFFECTS BY INTERPLAYING WITH OTHER SIGNALING PATHWAYS LIKE BMP-7, WNT/BETA-CATENIN AND MAP KINASE. SMAD3 IS THE CENTRAL PATHOLOGICAL GENE IN RENAL FIBROSIS, AND EPIGENETIC REGULATION OF TGF-BETA/SMAD3 IS A HOT TOPIC IN KIDNEY FIELD. ALTHOUGH DIRECT TARGETING TGF-BETA MAY CAUSE SIDE EFFECTS INCLUDING TUMORIGENESIS AND IMMUNE DISEASES, THE THERAPEUTIC STRATEGIES TARGETING THE BALANCE OF DOWNSTREAM SMAD3 AND SMAD7 MAY PREVENT OR DELAY THE PROGRESSION OF FIBROTIC KIDNEY DISEASE. 2018 5 3276 27 HEPATOCYTE GROWTH CONTROL BY SOCS1 AND SOCS3. THE EXTRAORDINARY CAPACITY OF THE LIVER TO REGENERATE FOLLOWING INJURY IS DEPENDENT ON COORDINATED AND REGULATED ACTIONS OF CYTOKINES AND GROWTH FACTORS. WHEREAS HEPATOCYTE GROWTH FACTOR (HGF) AND EPIDERMAL GROWTH FACTOR (EGF) ARE DIRECT MITOGENS TO HEPATOCYTES, INFLAMMATORY CYTOKINES SUCH AS TNFALPHA AND IL-6 ALSO PLAY ESSENTIAL ROLES IN THE LIVER REGENERATION PROCESS. THESE CYTOKINES AND GROWTH FACTORS ACTIVATE DIFFERENT SIGNALING PATHWAYS IN A SEQUENTIAL MANNER TO ELICIT HEPATOCYTE PROLIFERATION. THE KINETICS AND MAGNITUDE OF THESE HEPATOCYTE-ACTIVATING STIMULI ARE TIGHTLY REGULATED TO ENSURE RESTORATION OF A FUNCTIONAL LIVER MASS WITHOUT CAUSING UNCONTROLLED CELL PROLIFERATION. HEPATOCYTE PROLIFERATION CAN BECOME DEREGULATED UNDER CONDITIONS OF CHRONIC INFLAMMATION, LEADING TO ACCUMULATION OF GENETIC ABERRATIONS AND EVENTUAL NEOPLASTIC TRANSFORMATION. AMONG THE CONTROL MECHANISMS THAT REGULATE HEPATOCYTE PROLIFERATION, NEGATIVE FEEDBACK INHIBITION BY THE 'SUPPRESSOR OF CYTOKINE SIGNALING (SOCS)' FAMILY PROTEINS SOCS1 AND SOCS3 PLAY CRUCIAL ROLES IN ATTENUATING CYTOKINE AND GROWTH FACTOR SIGNALING. LOSS OF SOCS1 OR SOCS3 IN THE MOUSE LIVER INCREASES THE RATE OF LIVER REGENERATION AND RENDERS HEPATOCYTES SUSCEPTIBLE TO NEOPLASTIC TRANSFORMATION. THE FREQUENT EPIGENETIC REPRESSION OF THE SOCS1 AND SOCS3 GENES IN HEPATOCELLULAR CARCINOMA HAS STIMULATED RESEARCH IN UNDERSTANDING THE GROWTH REGULATORY MECHANISMS OF SOCS1 AND SOCS3 IN HEPATOCYTES. WHEREAS SOCS3 IS IMPLICATED IN REGULATING JAK-STAT SIGNALING INDUCED BY IL-6 AND ATTENUATING EGFR SIGNALING, SOCS1 IS CRUCIAL FOR THE REGULATION OF HGF SIGNALING. THESE TWO PROTEINS ALSO MODULE THE FUNCTIONS OF CERTAIN KEY PROTEINS THAT CONTROL THE CELL CYCLE. IN THIS REVIEW, WE DISCUSS THE CURRENT UNDERSTANDING OF THE FUNCTIONS OF SOCS1 AND SOCS3 IN CONTROLLING HEPATOCYTE PROLIFERATION, AND ITS IMPLICATIONS TO LIVER HEALTH AND DISEASE. 2019 6 4284 50 MICRORNA CIRCUITS REGULATE THE CANCER-INFLAMMATION LINK. GENETIC AND EPIGENETIC PERTURBATIONS ARE REQUIRED TO TRANSFORM NORMAL CELLS INTO CANCER CELLS. INFLAMMATORY SIGNALING PATHWAYS ARE ACTIVATED IN VARIOUS CANCERS, LINKING CHRONIC INFLAMMATION TO ONCOGENESIS. HOWEVER, THE MOLECULAR CIRCUITS THAT RESULT IN SUSTAINED ACTIVATION OF THESE INFLAMMATORY FACTORS ARE NOT YET WELL UNDERSTOOD. IN THE 28 JANUARY 2014 ISSUE OF SCIENCE SIGNALING, XIANG ET AL. IDENTIFIED A MICRORNA-MEDIATED ANTI-INFLAMMATORY CIRCUIT THAT IS REPRESSED EPIGENETICALLY IN RECEPTOR-NEGATIVE BREAST CANCERS. A HIGH-THROUGHPUT SCREEN FOR SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3)-REGULATED MICRORNAS REVEALED MICRORNA MIR-146B AS A DIRECT STAT3 TARGET IN MAMMARY EPITHELIAL CELLS, BUT DNA METHYLATION IN ITS PROMOTER AREA SUPPRESSED MIR-146B EXPRESSION IN CANCER CELLS. OVEREXPRESSION OF MIR-146B SUPPRESSED NUCLEAR FACTOR KAPPAB (NF-KAPPAB)-DEPENDENT EXPRESSION OF IL6 AND SUBSEQUENT STAT3 ACTIVATION AND DECREASED THE STAT3-INDUCED INVASIVENESS AND MESENCHYMAL PHENOTYPE OF BREAST CANCER CELLS. OVERALL, THIS STUDY CONTRIBUTES TO OUR UNDERSTANDING OF HOW INFLAMMATION IS INVOLVED IN ONCOGENIC TRANSFORMATION. FURTHER STUDIES COULD EVALUATE THE THERAPEUTIC POTENTIAL OF TARGETING THIS CIRCUIT IN ESTROGEN RECEPTOR-NEGATIVE BREAST CANCERS. 2014 7 799 21 CELLULAR SIGNALING AND POTENTIAL NEW TREATMENT TARGETS IN DIABETIC RETINOPATHY. DYSFUNCTION AND DEATH OF MICROVASCULAR CELLS AND IMBALANCE BETWEEN THE PRODUCTION AND THE DEGRADATION OF EXTRACELLULAR MATRIX (ECM) PROTEINS ARE A CHARACTERISTIC FEATURE OF DIABETIC RETINOPATHY (DR). GLUCOSE-INDUCED BIOCHEMICAL ALTERATIONS IN THE VASCULAR ENDOTHELIAL CELLS MAY ACTIVATE A CASCADE OF SIGNALING PATHWAYS LEADING TO INCREASED PRODUCTION OF ECM PROTEINS AND CELLULAR DYSFUNCTION/DEATH. CHRONIC DIABETES LEADS TO THE ACTIVATION OF A NUMBER OF SIGNALING PROTEINS INCLUDING PROTEIN KINASE C, PROTEIN KINASE B, AND MITOGEN-ACTIVATED PROTEIN KINASES. THESE SIGNALING CASCADES ARE ACTIVATED IN RESPONSE TO HYPERGLYCEMIA-INDUCED OXIDATIVE STRESS, POLYOL PATHWAY, AND ADVANCED GLYCATION END PRODUCT FORMATION AMONG OTHERS. THE ABERRANT SIGNALING PATHWAYS ULTIMATELY LEAD TO ACTIVATION OF TRANSCRIPTION FACTORS SUCH AS NUCLEAR FACTOR-KAPPAB AND ACTIVATING PROTEIN-1. THE ACTIVITY OF THESE TRANSCRIPTION FACTORS IS ALSO REGULATED BY EPIGENETIC MECHANISMS THROUGH TRANSCRIPTIONAL COACTIVATOR P300. THESE COMPLEX SIGNALING PATHWAYS MAY BE INVOLVED IN GLUCOSE-INDUCED ALTERATIONS OF ENDOTHELIAL CELL PHENOTYPE LEADING TO THE PRODUCTION OF INCREASED ECM PROTEINS AND VASOACTIVE EFFECTOR MOLECULES CAUSING FUNCTIONAL AND STRUCTURAL CHANGES IN THE MICROVASCULATURE. UNDERSTANDING OF SUCH MECHANISTIC PATHWAYS WILL HELP TO DEVELOP FUTURE ADJUVANT THERAPIES FOR DIABETIC RETINOPATHY. 2007 8 1479 25 DIVERSE TARGETS OF THE TRANSCRIPTION FACTOR STAT3 CONTRIBUTE TO T CELL PATHOGENICITY AND HOMEOSTASIS. STAT3, AN ESSENTIAL TRANSCRIPTION FACTOR WITH PLEIOTROPIC FUNCTIONS, PLAYS CRITICAL ROLES IN THE PATHOGENESIS OF AUTOIMMUNITY. DESPITE RECENT DATA LINKING STAT3 WITH INFLAMMATORY BOWEL DISEASE, EXACTLY HOW IT CONTRIBUTES TO CHRONIC INTESTINAL INFLAMMATION IS NOT KNOWN. USING A T CELL TRANSFER MODEL OF COLITIS, WE FOUND THAT STAT3 EXPRESSION IN T CELLS WAS ESSENTIAL FOR THE INDUCTION OF BOTH COLITIS AND SYSTEMIC INFLAMMATION. STAT3 WAS CRITICAL IN MODULATING THE BALANCE OF T HELPER 17 (TH17) AND REGULATORY T (TREG) CELLS, AS WELL AS IN PROMOTING CD4(+) T CELL PROLIFERATION. WE USED CHROMATIN IMMUNOPRECIPITATION AND MASSIVE PARALLEL SEQUENCING (CHIP-SEQ) TO DEFINE THE GENOME-WIDE TARGETS OF STAT3 IN CD4(+) T CELLS. WE FOUND THAT STAT3 BOUND TO MULTIPLE GENES INVOLVED IN TH17 CELL DIFFERENTIATION, CELL ACTIVATION, PROLIFERATION, AND SURVIVAL, REGULATING BOTH EXPRESSION AND EPIGENETIC MODIFICATIONS. THUS, STAT3 ORCHESTRATES MULTIPLE CRITICAL ASPECTS OF T CELL FUNCTION IN INFLAMMATION AND HOMEOSTASIS. 2010 9 911 30 CHRONIC EXPOSURE TO TNF REPROGRAMS CELL SIGNALING PATHWAYS IN FIBROBLAST-LIKE SYNOVIOCYTES BY ESTABLISHING LONG-TERM INFLAMMATORY MEMORY. FIBROBLAST-LIKE SYNOVIOCYTES (FLS) PLAY A CRITICAL ROLE IN THE PATHOGENESIS OF RHEUMATOID ARTHRITIS (RA). CHRONIC INFLAMMATION INDUCES TRANSCRIPTOMIC AND EPIGENETIC MODIFICATIONS THAT IMPARTS A PERSISTENT CATABOLIC PHENOTYPE TO THE FLS, DESPITE THEIR DISSOCIATION FROM THE INFLAMMATORY ENVIRONMENT. WE ANALYZED HIGH THROUGHPUT GENE EXPRESSION AND CHROMATIN ACCESSIBILITY DATA FROM HUMAN AND MOUSE FLS FROM OUR AND OTHER STUDIES AVAILABLE ON PUBLIC REPOSITORIES, WITH THE GOAL OF IDENTIFYING THE PERSISTENTLY REPROGRAMMED SIGNALING PATHWAYS DRIVEN BY CHRONIC INFLAMMATION. WE FOUND THAT THE GENE EXPRESSION CHANGES INDUCED BY SHORT-TERM TUMOR NECROSIS FACTOR-ALPHA (TNF) TREATMENT WERE LARGELY SUSTAINED IN THE FLS EXPOSED TO CHRONIC INFLAMMATION. THESE CHANGES THAT INCLUDED BOTH ACTIVATION AND REPRESSION OF GENE EXPRESSION, WERE ACCOMPANIED BY THE REMODELING OF CHROMATIN ACCESSIBILITY. THE SUSTAINED ACTIVATED GENES (SAGS) INCLUDED ESTABLISHED PRO-INFLAMMATORY SIGNALING COMPONENTS KNOWN TO ACT AT MULTIPLE LEVELS OF NF-KAPPAB, STAT AND AP-1 SIGNALING CASCADES. INTERESTINGLY, THE SUSTAINED REPRESSED GENES (SRGS) INCLUDED CRITICAL MEDIATORS AND TARGETS OF THE BMP SIGNALING PATHWAY. WE THUS IDENTIFIED SUSTAINED REPRESSION OF BMP SIGNALING AS A UNIQUE CONSTITUENT OF THE LONG-TERM INFLAMMATORY MEMORY INDUCED BY CHRONIC INFLAMMATION. WE POSTULATE THAT SIMULTANEOUS TARGETING OF THESE ACTIVATED AND REPRESSED SIGNALING PATHWAYS MAY BE NECESSARY TO COMBAT RA PERSISTENCE. 2020 10 4357 34 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 11 6110 34 THE EPIGENETIC ALTERATION OF SYNOVIAL CELL GENE EXPRESSION IN RHEUMATOID ARTHRITIS AND THE ROLES OF NUCLEAR FACTOR KAPPAB AND NOTCH SIGNALING PATHWAYS. RHEUMATOID ARTHRITIS (RA) IS A COMPLEX PROCESS OF CHRONIC AND PROGRESSIVE INFLAMMATION ASSOCIATED WITH ACTIVATION OF NUMEROUS SIGNALING MOLECULES AND TRANSCRIPTION FACTORS AND HYPERPROLIFERATION OF SYNOVIOCYTES OF THE AFFECTED JOINTS, ALTHOUGH THE GREATER PART OF ITS PATHOPHYSIOLOGICAL PROCESS IS EXPLAINED BY ACTIVATION OF NUCLEAR FACTOR KAPPAB (NF-KAPPAB). FOR EXAMPLE, THE SELF-PERPETUATING NATURE OF THE RHEUMATOID INFLAMMATION IS ASCRIBABLE TO OVEREXPRESSION OF THE PROINFLAMMATORY CYTOKINES TUMOR NECROSIS FACTOR ALPHA AND INTERLEUKIN-1BETA, KNOWN TO ELICIT THE ACTIVATION CASCADE FOR NF-KAPPAB AND ACTIVATOR PROTEIN-1 THAT ARE RESPONSIBLE FOR TRANSCRIPTIONAL INDUCTION OF THESE CYTOKINES AMONG OTHER TARGET GENES, WHICH CONFORM A POSITIVE FEEDBACK LOOP FOR CONTINUATION AND EXPANSION OF THE INFLAMMATORY RESPONSES. IN ADDITION, COMPARATIVE GENE EXPRESSION PROFILE ANALYSES HAVE REVEALED ACTIVATION OF A NUMBER OF GENES THAT EXPLAIN THE "TRANSFORMED-LIKE" PHENOTYPE OF SYNOVIOCYTES. AMONG THE GENES EXPRESSED IN RHEUMATOID SYNOVIOCYTES UPON INFLAMMATORY STIMULI, INDUCTION OF GENE EXPRESSION OF NOTCH PROTEINS AND ITS LIGAND HAVE BEEN FOUND. POSSIBLE ROLES OF NOTCH SIGNALING IN RA SYNOVIOCYTES ARE DISCUSSED. 2005 12 3864 29 JAK-STAT PATHWAY INHIBITION PARTIALLY RESTORES INTESTINAL HOMEOSTASIS IN HDAC1- AND HDAC2-INTESTINAL EPITHELIAL CELL-DEFICIENT MICE. WE HAVE PREVIOUSLY REPORTED THAT HISTONE DEACETYLASE EPIGENETIC REGULATOR HDAC1 AND HDAC2 DELETION IN INTESTINAL EPITHELIAL CELLS (IEC) DISRUPTS MUCOSAL TISSUE ARCHITECTURE AND BARRIER, CAUSING CHRONIC INFLAMMATION. IN THIS STUDY, PROTEOME AND TRANSCRIPTOME ANALYSIS REVEALED THE IMPORTANCE OF SIGNALING PATHWAYS INDUCED UPON GENETIC IEC-HDAC1 AND HDAC2 DELETION. INDEED, GENE ONTOLOGY BIOLOGICAL PROCESS ANALYSIS OF ENRICHED DEFICIENT IEC RNA AND PROTEINS IDENTIFIED COMMON PATHWAYS, INCLUDING LIPID METABOLIC AND OXIDATION-REDUCTION PROCESS, CELL ADHESION, AND ANTIGEN PROCESSING AND PRESENTATION, RELATED TO IMMUNE RESPONSES, CORRELATING WITH DYSREGULATION OF MAJOR HISTOCOMPATIBILITY COMPLEX (MHC) CLASS II GENES. TOP UPSTREAM REGULATORS INCLUDED REGULATORS ASSOCIATED WITH ENVIRONMENTAL SENSING PATHWAYS TO XENOBIOTICS, MICROBIAL AND DIET-DERIVED LIGANDS, AND ENDOGENOUS METABOLITES. PROTEOME ANALYSIS REVEALED MTOR SIGNALING IEC-SPECIFIC DEFECTS. IN ADDITION TO MTOR, THE STAT AND NOTCH PATHWAYS WERE DYSREGULATED SPECIFICALLY IN JEJUNAL IEC. TO DETERMINE THE IMPACT OF PATHWAY DYSREGULATION ON MUTANT JEJUNUM ALTERATIONS, WE TREATED MUTANT MICE WITH TOFACITINIB, A JAK INHIBITOR. TREATMENT WITH THE INHIBITOR PARTIALLY CORRECTED PROLIFERATION AND TIGHT JUNCTION DEFECTS, AS WELL AS NICHE STABILIZATION BY INCREASING PANETH CELL NUMBERS. THUS, IEC-SPECIFIC HISTONE DEACETYLASES 1 (HDAC1) AND 2 (HDAC2) SUPPORT INTESTINAL HOMEOSTASIS BY REGULATING SURVIVAL AND TRANSLATION PROCESSES, AS WELL AS DIFFERENTIATION AND METABOLIC PATHWAYS. HDAC1 AND HDAC2 MAY PLAY AN IMPORTANT ROLE IN THE REGULATION OF IEC-SPECIFIC INFLAMMATORY RESPONSES BY CONTROLLING, DIRECTLY OR INDIRECTLY, THE JAK/STAT PATHWAY. IEC-SPECIFIC JAK/STAT PATHWAY DEREGULATION MAY BE, AT LEAST IN PART, RESPONSIBLE FOR INTESTINAL HOMEOSTASIS DISRUPTION IN MUTANT MICE. 2021 13 6263 30 THE MULTIPLE WAYS WNT SIGNALING CONTRIBUTES TO ACUTE LEUKEMIA PATHOGENESIS. WNT PROTEINS CONSTITUTE A VERY CONSERVED FAMILY OF SECRETED GLYCOPROTEINS THAT ACT AS SHORT-RANGE LIGANDS FOR SIGNALING WITH CRITICAL ROLES IN HEMATOPOIESIS, EMBRYONIC DEVELOPMENT, AND TISSUE HOMEOSTASIS. THESE PROTEINS TRANSDUCE SIGNALS VIA THE CANONICAL PATHWAY, WHICH IS BETA-CATENIN-MEDIATED AND BETTER-CHARACTERIZED, OR VIA MORE DIVERSE NONCANONICAL PATHWAYS THAT ARE BETA-CATENIN INDEPENDENT AND COMPRISE THE PLANAR CELL POLARITY (PCP) PATHWAY AND THE WNT/CA(++) PATHWAYS. SEVERAL PROTEINS REGULATE WNT SIGNALING THROUGH A VARIETY OF SOPHISTICATED MECHANISMS. DISORDERS WITHIN THE PATHWAY CAN CONTRIBUTE TO VARIOUS HUMAN DISEASES, AND THE DYSREGULATION OF WNT PATHWAYS BY DIFFERENT MOLECULAR MECHANISMS IS IMPLICATED IN THE PATHOGENESIS OF MANY TYPES OF CANCER, INCLUDING THE HEMATOLOGICAL MALIGNANCIES. THE TYPES OF LEUKEMIA DIFFER CONSIDERABLY AND CAN BE SUBDIVIDED INTO CHRONIC, MYELOID OR LYMPHOCYTIC, AND ACUTE, MYELOID OR LYMPHOCYTIC, LEUKEMIA, ACCORDING TO THE DIFFERENTIATION STAGE OF THE PREDOMINANT CELLS, THE PROGENITOR LINEAGE, THE DIAGNOSTIC AGE STRATA, AND THE SPECIFIC MOLECULAR DRIVERS BEHIND THEIR DEVELOPMENT. HERE, WE REVIEW THE ROLE OF WNT SIGNALING IN NORMAL HEMATOPOIESIS AND DISCUSS IN DETAIL THE MULTIPLE WAYS CANONICAL WNT SIGNALING CAN BE DYSREGULATED IN ACUTE LEUKEMIA, INCLUDING ALTERATIONS IN GENE EXPRESSION AND PROTEIN LEVELS, EPIGENETIC REGULATION, AND MUTATIONS. FURTHERMORE, WE HIGHLIGHT THE DIFFERENT IMPACTS OF THESE ALTERATIONS, CONSIDERING THE DISTINCT FORMS OF THE DISEASE, AND THE THERAPEUTIC POTENTIAL OF TARGETING WNT SIGNALING. 2020 14 5992 27 TGF-BETA: THE MASTER REGULATOR OF FIBROSIS. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS THE PRIMARY FACTOR THAT DRIVES FIBROSIS IN MOST, IF NOT ALL, FORMS OF CHRONIC KIDNEY DISEASE (CKD). INHIBITION OF THE TGF-BETA ISOFORM, TGF-BETA1, OR ITS DOWNSTREAM SIGNALLING PATHWAYS SUBSTANTIALLY LIMITS RENAL FIBROSIS IN A WIDE RANGE OF DISEASE MODELS WHEREAS OVEREXPRESSION OF TGF-BETA1 INDUCES RENAL FIBROSIS. TGF-BETA1 CAN INDUCE RENAL FIBROSIS VIA ACTIVATION OF BOTH CANONICAL (SMAD-BASED) AND NON-CANONICAL (NON-SMAD-BASED) SIGNALLING PATHWAYS, WHICH RESULT IN ACTIVATION OF MYOFIBROBLASTS, EXCESSIVE PRODUCTION OF EXTRACELLULAR MATRIX (ECM) AND INHIBITION OF ECM DEGRADATION. THE ROLE OF SMAD PROTEINS IN THE REGULATION OF FIBROSIS IS COMPLEX, WITH COMPETING PROFIBROTIC AND ANTIFIBROTIC ACTIONS (INCLUDING IN THE REGULATION OF MESENCHYMAL TRANSITIONING), AND WITH COMPLEX INTERPLAY BETWEEN TGF-BETA/SMADS AND OTHER SIGNALLING PATHWAYS. STUDIES OVER THE PAST 5 YEARS HAVE IDENTIFIED ADDITIONAL MECHANISMS THAT REGULATE THE ACTION OF TGF-BETA1/SMAD SIGNALLING IN FIBROSIS, INCLUDING SHORT AND LONG NONCODING RNA MOLECULES AND EPIGENETIC MODIFICATIONS OF DNA AND HISTONE PROTEINS. ALTHOUGH DIRECT TARGETING OF TGF-BETA1 IS UNLIKELY TO YIELD A VIABLE ANTIFIBROTIC THERAPY DUE TO THE INVOLVEMENT OF TGF-BETA1 IN OTHER PROCESSES, GREATER UNDERSTANDING OF THE VARIOUS PATHWAYS BY WHICH TGF-BETA1 CONTROLS FIBROSIS HAS IDENTIFIED ALTERNATIVE TARGETS FOR THE DEVELOPMENT OF NOVEL THERAPEUTICS TO HALT THIS MOST DAMAGING PROCESS IN CKD. 2016 15 1874 29 EMERGING ROLE OF NF-KAPPAB SIGNALING IN THE INDUCTION OF SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). THE MAJOR HALLMARK OF CELLULAR SENESCENCE IS AN IRREVERSIBLE CELL CYCLE ARREST AND THUS IT IS A POTENT TUMOR SUPPRESSOR MECHANISM. GENOTOXIC INSULTS, E.G. OXIDATIVE STRESS, ARE IMPORTANT INDUCERS OF THE SENESCENT PHENOTYPE WHICH IS CHARACTERIZED BY AN ACCUMULATION OF SENESCENCE-ASSOCIATED HETEROCHROMATIC FOCI (SAHF) AND DNA SEGMENTS WITH CHROMATIN ALTERATIONS REINFORCING SENESCENCE (DNA-SCARS). INTERESTINGLY, SENESCENT CELLS SECRETE PRO-INFLAMMATORY FACTORS AND THUS THE CONDITION HAS BEEN CALLED THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). EMERGING DATA HAS REVEALED THAT NF-KAPPAB SIGNALING IS THE MAJOR SIGNALING PATHWAY WHICH STIMULATES THE APPEARANCE OF SASP. IT IS KNOWN THAT DNA DAMAGE PROVOKES NF-KAPPAB SIGNALING VIA A VARIETY OF SIGNALING COMPLEXES CONTAINING NEMO PROTEIN, AN NF-KAPPAB ESSENTIAL MODIFIER, AS WELL AS VIA THE ACTIVATION OF SIGNALING PATHWAYS OF P38MAPK AND RIG-1, RETINOIC ACID INDUCIBLE GENE-1. GENOMIC INSTABILITY EVOKED BY CELLULAR STRESS TRIGGERS EPIGENETIC CHANGES, E.G. RELEASE OF HMGB1 PROTEINS WHICH ARE ALSO POTENT ENHANCERS OF INFLAMMATORY RESPONSES. MOREOVER, ENVIRONMENTAL STRESS AND CHRONIC INFLAMMATION CAN STIMULATE P38MAPK AND CERAMIDE SIGNALING AND INDUCE CELLULAR SENESCENCE WITH PRO-INFLAMMATORY RESPONSES. ON THE OTHER HAND, TWO CYCLIN-DEPENDENT KINASE INHIBITORS, P16INK4A AND P14ARF, ARE EFFECTIVE INHIBITORS OF NF-KAPPAB SIGNALING. WE WILL REVIEW IN DETAIL THE SIGNALING PATHWAYS WHICH ACTIVATE NF-KAPPAB SIGNALING AND TRIGGER SASP IN SENESCENT CELLS. 2012 16 2082 31 EPIGENETIC DOWNREGULATION OF SFRP4 CONTRIBUTES TO EPIDERMAL HYPERPLASIA IN PSORIASIS. PSORIASIS IS A CHRONIC RECURRENT INFLAMMATORY SKIN DISORDER CHARACTERIZED BY THE DYSREGULATED CROSS-TALK BETWEEN EPIDERMAL KERATINOCYTES AND IMMUNE CELLS, LEADING TO KERATINOCYTE HYPERPROLIFERATION. SEVERAL STUDIES DEMONSTRATED THAT WNT PATHWAY GENES WERE DIFFERENTIALLY EXPRESSED IN PSORIATIC PLAQUES AND LIKELY WERE INVOLVED IN THE PATHOPHYSIOLOGY OF DISEASE. HOWEVER, THE MOLECULAR MECHANISMS UNDERLYING WNT SIGNALING REGULATION IN EPIDERMAL HYPERPLASIA IN PSORIASIS REMAIN LARGELY UNKNOWN. WE REPORT THAT THE EXPRESSION OF SECRETED FRIZZLED-RELATED PROTEIN (SFRP) 4, A NEGATIVE REGULATOR OF THE WNT SIGNALING PATHWAY, WAS DIMINISHED IN LESIONAL SKIN OF MOUSE MODELS AND PATIENTS WITH PSORIASIS. SFRP4 DIRECTLY INHIBITED EXCESSIVE KERATINOCYTE PROLIFERATION EVOKED BY PROINFLAMMATORY CYTOKINES IN VITRO. PHARMACOLOGICAL INHIBITION OF WNT SIGNALING OR INTRADERMAL INJECTION OF SFRP4 DECREASED THE SEVERITY OF THE PSORIASIFORM SKIN PHENOTYPE IN VIVO, INCLUDING DECREASED ACANTHOSIS AND REDUCED LEUKOCYTE INFILTRATION. MECHANISTICALLY, WE IDENTIFIED THAT ABERRANT PROMOTER METHYLATION RESULTED IN EPIGENETIC DOWNREGULATION OF SFRP4 IN INFLAMED SKIN OF PATIENTS WITH PSORIASIS AND IN THE IL-23-INDUCED MOUSE MODEL. OUR FINDINGS SUGGEST THAT THIS EPIGENETIC EVENT IS CRITICALLY INVOLVED IN THE PATHOGENESIS OF PSORIASIS, AND THE DOWNREGULATION OF SFRP4 BY CPG ISLAND METHYLATION IS ONE POSSIBLE MECHANISM CONTRIBUTING TO THE HYPERPLASIA OF EPIDERMIS IN THE DISEASE. 2015 17 2435 37 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 18 3688 36 INFLAMMATION: GEARING THE JOURNEY TO CANCER. CHRONIC INFLAMMATION PLAYS A MULTIFACETED ROLE IN CARCINOGENESIS. MOUNTING EVIDENCE FROM PRECLINICAL AND CLINICAL STUDIES SUGGESTS THAT PERSISTENT INFLAMMATION FUNCTIONS AS A DRIVING FORCE IN THE JOURNEY TO CANCER. THE POSSIBLE MECHANISMS BY WHICH INFLAMMATION CAN CONTRIBUTE TO CARCINOGENESIS INCLUDE INDUCTION OF GENOMIC INSTABILITY, ALTERATIONS IN EPIGENETIC EVENTS AND SUBSEQUENT INAPPROPRIATE GENE EXPRESSION, ENHANCED PROLIFERATION OF INITIATED CELLS, RESISTANCE TO APOPTOSIS, AGGRESSIVE TUMOR NEOVASCULARIZATION, INVASION THROUGH TUMOR-ASSOCIATED BASEMENT MEMBRANE AND METASTASIS, ETC. INFLAMMATION-INDUCED REACTIVE OXYGEN AND NITROGEN SPECIES CAUSE DAMAGE TO IMPORTANT CELLULAR COMPONENTS (E.G., DNA, PROTEINS AND LIPIDS), WHICH CAN DIRECTLY OR INDIRECTLY CONTRIBUTE TO MALIGNANT CELL TRANSFORMATION. OVEREXPRESSION, ELEVATED SECRETION, OR ABNORMAL ACTIVATION OF PROINFLAMMATORY MEDIATORS, SUCH AS CYTOKINES, CHEMOKINES, CYCLOOXYGENASE-2, PROSTAGLANDINS, INDUCIBLE NITRIC OXIDE SYNTHASE, AND NITRIC OXIDE, AND A DISTINCT NETWORK OF INTRACELLULAR SIGNALING MOLECULES INCLUDING UPSTREAM KINASES AND TRANSCRIPTION FACTORS FACILITATE TUMOR PROMOTION AND PROGRESSION. WHILE INFLAMMATION PROMOTES DEVELOPMENT OF CANCER, COMPONENTS OF THE TUMOR MICROENVIRONMENT, SUCH AS TUMOR CELLS, STROMAL CELLS IN SURROUNDING TISSUE AND INFILTRATED INFLAMMATORY/IMMUNE CELLS GENERATE AN INTRATUMORAL INFLAMMATORY STATE BY ABERRANT EXPRESSION OR ACTIVATION OF SOME PROINFLAMMATORY MOLECULES. MANY OF PROINFLAMMATORY MEDIATORS, ESPECIALLY CYTOKINES, CHEMOKINES AND PROSTAGLANDINS, TURN ON THE ANGIOGENIC SWITCHES MAINLY CONTROLLED BY VASCULAR ENDOTHELIAL GROWTH FACTOR, THEREBY INDUCING INFLAMMATORY ANGIOGENESIS AND TUMOR CELL-STROMA COMMUNICATION. THIS WILL END UP WITH TUMOR ANGIOGENESIS, METASTASIS AND INVASION. MOREOVER, CELLULAR MICRORNAS ARE EMERGING AS A POTENTIAL LINK BETWEEN INFLAMMATION AND CANCER. THE PRESENT ARTICLE HIGHLIGHTS THE ROLE OF VARIOUS PROINFLAMMATORY MEDIATORS IN CARCINOGENESIS AND THEIR PROMISE AS POTENTIAL TARGETS FOR CHEMOPREVENTION OF INFLAMMATION-ASSOCIATED CARCINOGENESIS. 2008 19 6757 36 WNT SIGNALING IN LIVER FIBROSIS: PROGRESS, CHALLENGES AND POTENTIAL DIRECTIONS. LIVER FIBROSIS IS A COMMON WOUND-HEALING RESPONSE TO CHRONIC LIVER INJURIES, INCLUDING ALCOHOLIC OR DRUG TOXICITY, PERSISTENT VIRAL INFECTION, AND GENETIC FACTORS. MYOFIBROBLASTIC TRANSDIFFERENTIATION (MTD) IS THE PIVOTAL EVENT DURING LIVER FIBROGENESIS, AND RESEARCH IN THE PAST FEW YEARS HAS IDENTIFIED KEY MEDIATORS AND MOLECULAR MECHANISMS RESPONSIBLE FOR MTD OF HEPATIC STELLATE CELLS (HSCS). HSCS ARE UNDIFFERENTIATED CELLS WHICH PLAY AN IMPORTANT ROLE IN LIVER REGENERATION. RECENT EVIDENCE DEMONSTRATES THAT HSCS DERIVE FROM MESODERM AND AT LEAST IN PART VIA SEPTUM TRANSVERSUM AND MESOTHELIUM, AND HSCS EXPRESS MARKERS FOR DIFFERENT CELL TYPES WHICH DERIVE FROM MULTIPOTENT MESENCHYMAL PROGENITORS. THERE IS A REGULATORY COMMONALITY BETWEEN DIFFERENTIATION OF ADIPOCYTES AND THAT OF HSC, AND THE SHIFT FROM ADIPOGENIC TO MYOGENIC OR NEURONAL PHENOTYPE CHARACTERIZES HSC MTD. CENTRAL OF THIS SHIFT IS A LOSS OF EXPRESSION OF THE MASTER ADIPOGENIC REGULATOR PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR GAMMA (PPARGAMMA). RESTORED EXPRESSION OF PPARGAMMA AND/OR OTHER ADIPOGENIC TRANSCRIPTION GENES CAN REVERSE MYOFIBROBLASTIC HSCS TO DIFFERENTIATED CELLS. VERTEBRATE WNT AND DROSOPHILA WINGLESS ARE HOMOLOGOUS GENES, AND THEIR TRANSLATED PROTEINS HAVE BEEN SHOWN TO PARTICIPATE IN THE REGULATION OF CELL PROLIFERATION, CELL POLARITY, CELL DIFFERENTIATION, AND OTHER BIOLOGICAL ROLES. MORE RECENTLY, WNT SIGNALING IS IMPLICATED IN HUMAN FIBROSING DISEASES, SUCH AS PULMONARY FIBROSIS, RENAL FIBROSIS, AND LIVER FIBROSIS. BLOCKING THE CANONICAL WNT SIGNAL PATHWAY WITH THE CO-RECEPTOR ANTAGONIST DICKKOPF-1 (DKK1) ABROGATES THESE EPIGENETIC REPRESSIONS AND RESTORES THE GENE PPARGAMMA EXPRESSION AND HSC DIFFERENTIATION. THE IDENTIFIED MORPHOGEN MEDIATED EPIGENETIC REGULATION OF PPARGAMMA AND HSC DIFFERENTIATION ALSO SERVES AS NOVEL THERAPEUTIC TARGETS FOR LIVER FIBROSIS AND LIVER REGENERATION. IN CONCLUSION, THE WNT SIGNALING PROMOTES LIVER FIBROSIS BY ENHANCING HSC ACTIVATION AND SURVIVAL, AND WE HEREIN DISCUSS WHAT WE CURRENTLY KNOW AND WHAT WE EXPECT WILL COME IN THIS FIELD IN THE NEXT FUTURE. 2013 20 3217 37 HEDGEHOG/GLI AND PI3K SIGNALING IN THE INITIATION AND MAINTENANCE OF CHRONIC LYMPHOCYTIC LEUKEMIA. THE INITIATION AND MAINTENANCE OF A MALIGNANT PHENOTYPE REQUIRES COMPLEX AND SYNERGISTIC INTERACTIONS OF MULTIPLE ONCOGENIC SIGNALS. THE HEDGEHOG (HH)/GLI PATHWAY HAS BEEN IMPLICATED IN A VARIETY OF CANCER ENTITIES AND TARGETED PATHWAY INHIBITION IS OF THERAPEUTIC RELEVANCE. SIGNAL CROSS-TALK WITH OTHER CANCER PATHWAYS INCLUDING PI3K/AKT MODULATES HH/GLI SIGNAL STRENGTH AND ITS ONCOGENICITY. IN THIS STUDY, WE ADDRESSED THE ROLE OF HH/GLI AND ITS PUTATIVE INTERACTION WITH THE PI3K/AKT CASCADE IN THE INITIATION AND MAINTENANCE OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). USING TRANSGENIC MOUSE MODELS, WE SHOW THAT B-CELL-SPECIFIC CONSTITUTIVE ACTIVATION OF HH/GLI SIGNALING EITHER AT THE LEVEL OF THE HH EFFECTOR AND DRUG TARGET SMOOTHENED OR AT THE LEVEL OF THE GLI TRANSCRIPTION FACTORS DOES NOT SUFFICE TO INITIATE A CLL-LIKE PHENOTYPE CHARACTERIZED BY THE ACCUMULATION OF CD5(+) B CELLS IN THE LYMPHATIC SYSTEM AND PERIPHERAL BLOOD. FURTHERMORE, HH/GLI ACTIVATION IN PTEN-DEFICIENT B CELLS WITH ACTIVATED PI3K/AKT SIGNALING FAILED TO ENHANCE THE EXPANSION OF LEUKEMIC CD5(+) B CELLS, SUGGESTING THAT GENETIC OR EPIGENETIC ALTERATIONS LEADING TO ABERRANT HH/GLI SIGNALING IN B CELLS DO NOT SUFFICE TO ELICIT A CLL-LIKE PHENOTYPE IN MICE. BY CONTRAST, WE IDENTIFY A CRITICAL ROLE OF GLI AND PI3K SIGNALING FOR THE SURVIVAL OF HUMAN PRIMARY CLL CELLS. WE SHOW THAT COMBINED TARGETING OF GLI AND PI3K/AKT/MTOR SIGNALING CAN HAVE A SYNERGISTIC THERAPEUTIC EFFECT IN CELLS FROM A SUBGROUP OF CLL PATIENTS, THEREBY PROVIDING A BASIS FOR THE EVALUATION OF FUTURE COMBINATION THERAPIES TARGETING HH/GLI AND PI3K SIGNALING IN THIS COMMON HEMATOPOIETIC MALIGNANCY. 2015