1 3216 160 HEDGEHOG SIGNALING PATHWAY AND GASTROINTESTINAL STEM CELL SIGNALING NETWORK (REVIEW). HEDGEHOG, BMP/TGFBETA, FGF, WNT AND NOTCH SIGNALING PATHWAYS CONSTITUTE THE STEM CELL SIGNALING NETWORK, WHICH PLAYS A KEY ROLE IN A VARIETY OF PROCESSES, SUCH AS EMBRYOGENESIS, MAINTENANCE OF ADULT TISSUE HOMEOSTASIS, TISSUE REPAIR DURING CHRONIC PERSISTENT INFLAMMATION, AND CARCINOGENESIS. SONIC HEDGEHOG (SHH), INDIAN HEDGEHOG (IHH) AND DESERT HEDGEHOG (DHH) BIND TO PTCH1/PTCH OR PTCH2 RECEPTOR TO RELEASE SMOOTHENED (SMO) SIGNAL TRANSDUCER FROM PATCHED-DEPENDENT SUPPRESSION. SMO THEN ACTIVATES STK36 SERINE/THREONINE KINASE TO STABILIZE GLI FAMILY MEMBERS AND TO PHOSPHORYLATE SUFU FOR NUCLEAR ACCUMULATION OF GLI. HEDGEHOG SIGNALING ACTIVATION LEADS TO GLI-DEPENDENT TRANSCRIPTIONAL ACTIVATION OF TARGET GENES, SUCH AS GLI1, PTCH1, CCND2, FOXL1, JAG2 AND SFRP1. GLI1-DEPENDENT POSITIVE FEEDBACK LOOP COMBINED WITH PTCH1-DEPENDENT NEGATIVE FEEDBACK LOOP GIVES RISE TO TRANSIENT PROLIFERATION OF HEDGEHOG TARGET CELLS. IGUANA HOMOLOGS (DZIP1 AND DZIP1L) AND COSTAL-2 HOMOLOGS (KIF7 AND KIF27) ARE IDENTIFIED BY COMPARATIVE INTEGROMICS. SHH-DEPENDENT PARIETAL CELL PROLIFERATION IS IMPLICATED IN GASTRIC MUCOSAL REPAIR DURING CHRONIC HELICOBACTER PYLORI INFECTION. BMP-RUNX3 SIGNALING INDUCES IHH EXPRESSION IN SURFACE DIFFERENTIATED EPITHELIAL CELLS OF STOMACH AND INTESTINE. HEDGEHOG SIGNALS FROM EPITHELIAL CELLS THEN INDUCES FOXL1-MEDIATED BMP4 UPREGULATION IN MESENCHYMAL CELLS. HEDGEHOG SIGNALING IS FREQUENTLY ACTIVATED IN ESOPHAGEAL CANCER, GASTRIC CANCER AND PANCREATIC CANCER DUE TO TRANSCRIPTIONAL UPREGULATION OF HEDGEHOG LIGANDS AND EPIGENETIC SILENCING OF HHIP1/HHIP GENE, ENCODING THE HEDGEHOG INHIBITOR. HOWEVER, HEDGEHOG SIGNALING IS RARELY ACTIVATED IN COLORECTAL CANCER DUE TO NEGATIVE REGULATION BY THE CANONICAL WNT SIGNALING PATHWAY. HEDGEHOG SIGNALING MOLECULES OR TARGETS, SUCH AS SHH, IHH, HHIP1, PTCH1 AND GLI1, ARE APPLIED AS BIOMARKERS FOR CANCER DIAGNOSTICS, PROGNOSTICS AND THERAPEUTICS. SMALL-MOLECULE INHIBITORS FOR SMO OR STK36 ARE SUITABLE TO BE USED FOR TREATMENT OF HEDGEHOG-DEPENDENT CANCER. 2006 2 6756 61 WNT ANTAGONIST, SFRP1, IS HEDGEHOG SIGNALING TARGET. HEDGEHOG AND WNT SIGNALING PATHWAYS NETWORK TOGETHER DURING EMBRYOGENESIS AND CARCINOGENESIS. HEDGEHOG SIGNALING IN INTESTINAL EPITHELIUM REPRESSES CANONICAL WNT SIGNALING TO RESTRICT EXPRESSION OF WNT TARGET GENES TO STEM OR PROGENITOR CELLS; HOWEVER, THE MECHANISM REMAINS UNCLEAR. THE HEDGEHOG SIGNAL IS TRANSDUCED TO GLI FAMILY TRANSCRIPTION FACTORS THOUGH PATCHED RECEPTOR, SMOOTHENED SIGNAL TRANSDUCER, AND OTHER SIGNALING COMPONENTS, SUCH AS KIF27, KIF7, STK36, SUFU, AND DZIP1. HERE, WE SEARCHED FOR THE GLI-BINDING SITE WITHIN THE PROMOTER REGION OF GENES ENCODING SECRETED-TYPE WNT SIGNAL INHIBITORS, INCLUDING SFRP1, SFRP2, SFRP3, SFRP4, SFRP5, DKK1, DKK2, DKK3, DKK4, AND WIF1. THE GLI-BINDING SITE WAS IDENTIFIED WITHIN THE HUMAN SFRP1 PROMOTER BASED ON BIOINFORMATICS AND HUMAN INTELLIGENCE. THE CHIMPANZEE SFRP1 GENE WAS IDENTIFIED WITHIN THE NW_110515.1 GENOME SEQUENCE. THE GLI-BINDING SITE OF THE HUMAN SFRP1 PROMOTER WAS CONSERVED IN CHIMPANZEE SFRP1, MOUSE SFRP1, AND RAT SFRP1 PROMOTERS. SFRP1 IS THE EVOLUTIONARILY CONSERVED TARGET OF THE HEDGEHOG-GLI SIGNALING PATHWAY. EXPRESSION DOMAIN ANALYSES BASED ON TEXT MINING REVEALED THAT INDIAN HEDGEHOG (IHH), SFRP1, AND WNT6 ARE EXPRESSED IN DIFFERENTIATED INTESTINAL EPITHELIAL CELLS, MESENCHYMAL CELLS, AND STEM/PROGENITOR CELLS, RESPECTIVELY. HEDGEHOG IS SECRETED FROM DIFFERENTIATED EPITHELIAL CELLS TO INDUCE SFRP1 EXPRESSION IN MESENCHYMAL CELLS, WHICH KEEPS DIFFERENTIATED EPITHELIAL CELLS AWAY FROM THE EFFECTS OF CANONICAL WNT SIGNALING. THESE FACTS INDICATE THAT SFRP1 IS THE HEDGEHOG TARGET TO CONFINE CANONICAL WNT SIGNALING WITHIN STEM OR PROGENITOR CELLS. THEREFORE, EPIGENETIC CPG HYPERMETHYLATION OF THE SFRP1 PROMOTER DURING CHRONIC PERSISTENT INFLAMMATION AND AGING LEADS TO THE OCCURRENCE OF GASTROINTESTINAL CANCERS, SUCH AS COLORECTAL CANCER AND GASTRIC CANCER, THROUGH THE BREAKDOWN OF HEDGEHOG-DEPENDENT WNT SIGNAL INHIBITION. 2006 3 1730 56 DYSREGULATION OF STEM CELL SIGNALING NETWORK DUE TO GERMLINE MUTATION, SNP, HELICOBACTER PYLORI INFECTION, EPIGENETIC CHANGE AND GENETIC ALTERATION IN GASTRIC CANCER. GENETIC FACTORS, HELICOBACTER PYLORI INFECTION, SALT OVER-UPTAKE, DECREASED VEGETABLE/FRUIT CONSUMPTION, SMOKING, AND METABOLIC SYNDROME ARE RISK FACTORS OF HUMAN GASTRIC CANCER. GERMLINE MUTATIONS OF CDH1 GENE, AND SNPS OF PTPN11 (SHP2), TLR4, IL1B, TNFA, BMP6, GDF15 AND RUNX3 GENES ARE ASSOCIATED WITH GASTRIC CANCER. HELICOBACTER PYLORI ACTIVATES CAGA-SHP2-ERK AND PEPTIDOGLYCAN-NOD1-NFKAPPAB SIGNALING CASCADES IN GASTRIC EPITHELIAL CELLS USING TYPE IV SECRETION SYSTEM, AND ALSO TRAF6-MAP3K7-NFKAPPAB AND TRAF6-MAP3K7-AP-1 SIGNALING CASCADES IN EPITHELIAL AND IMMUNE CELLS THROUGH LIPOPOLYSACCHARIDE RECOGNITION BY TLR2 OR TLR4. IL-1BETA, IL-6, IL-8, TNFALPHA AND IFNGAMMA ARE ELEVATED IN GASTRIC MUCOSA WITH HELICOBACTER PYLORI INFECTION. IL-6 AND TNFALPHA INDUCE UPREGULATION OF WNT5A AND WNT10B, RESPECTIVELY. WNT SIGNALS ARE TRANSDUCED TO BETA-CATENIN-TCF/LEF, RHOA, JNK, PKC, NFAT, AND NLK SIGNALING CASCADES. WNT-BETA-CATENIN-TCF/LEF SIGNALING INDUCES UPREGULATION OF MYC, CCND1, WISP1, FGF20, JAG1 AND DKK1 GENES. NOTCH SIGNALS ARE TRANSDUCED TO CSL-NICD-MAML AND NFKAPPAB SIGNALING CASCADES. FGF SIGNALS ARE TRANSDUCED TO ERK, PI3K-AKT, PKC, AND NFAT SIGNALING CASCADES. HELICOBACTER PYLORI INFECTION INDUCES SHH UPREGULATION IN PARIETAL CELL LINEAGE, WHILE BMP SIGNALS INDUCE IHH UPREGULATION IN PIT CELL LINEAGE. HEDGEHOG SIGNALS INDUCE UPREGULATION OF GLI1, PTCH1, CCND2, FOXL1, JAG2 AND SFRP1 GENES. JAG1 AND JAG2 ACTIVATE NOTCH SIGNALING, WHILE DKK1 AND SFRP1 INHIBIT WNT SIGNALING. STEM CELL SIGNALING NETWORK, CONSISTING OF WNT, NOTCH, FGF, HEDGEHOG AND BMP SIGNALING PATHWAYS, IS ACTIVATED DURING CHRONIC HELICOBACTER PYLORI INFECTION. EPIGENETIC SILENCING OF SFRP1 GENE OCCURS IN THE EARLIER STAGE OF CARCINOGENESIS IN THE STOMACH, WHILE AMPLIFICATION AND OVEREXPRESSION OF FGFR2 GENE IN THE LATER STAGE. DYSREGULATION OF THE STEM CELL SIGNALING NETWORK DUE TO THE ACCUMULATION OF GERMLINE MUTATION, SNP, HELICOBACTER PYLORI INFECTION, EPIGENETIC CHANGE AND GENETIC ALTERATION GIVES RISE TO GASTRIC CANCER. SNP TYPING AND CUSTOM-MADE MICROARRAY ANALYSES ON GENES ENCODING STEM CELL SIGNALING MOLECULES COULD BE UTILIZED FOR THE PERSONALIZED MEDICINE. 2007 4 4162 36 MECP2 REGULATES PTCH1 EXPRESSION THROUGH DNA METHYLATION IN RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC AUTOIMMUNE INFLAMMATORY DISEASE, IN WHICH PATHOGENESIS IS NOT CLEAR. MANY RESEARCH DEMONSTRATED THAT FIBROBLAST-LIKE SYNOVIOCYTES (FLSS) PLAY A KEY ROLE IN RA PATHOGENESIS, JOIN IN THE CARTILAGE INJURY AND HYPERPLASIA OF THE SYNOVIUM, AND CONTRIBUTE TO THE RELEASE OF INFLAMMATORY CYTOKINES. WE USED ADJUVANT ARTHRITIS (AA) RATS AS RA ANIMAL MODELS. THE METHYL-CPG-BINDING PROTEIN 2 (MECP2) ENABLES THE SUPPRESSED CHROMATIN STRUCTURE TO BE SELECTIVELY DETECTED IN AA FLSS. OVEREXPRESSION OF THIS PROTEIN LEADS TO AN INCREASE OF INTEGRAL METHYLATION LEVELS. SOME RESEARCH HAS CONFIRMED THE HEDGEHOG (HH) SIGNALING PATHWAY PLAYS AN IMPORTANT ROLE IN RA PATHOGENESIS; FURTHERMORE, PATCHED 1 (PTCH1) IS A NEGATIVE FRACTION OF HH SIGNALING PATHWAY. WE USED 5-AZA-2'-DEOXYCYTIDINE (5-AZADC) AS DNA METHYLATION INHIBITOR. IN OUR RESEARCH, WE FOUND MECP2 REDUCED PTCH1 EXPRESSION IN AA FLSS; 5-AZADC OBSTRUCTED THE LOSS OF PTCH1 EXPRESSION. 5-AZADC, TREATMENT OF AA FLSS, ALSO BLOCKS THE RELEASE OF INFLAMMATORY CYTOKINES. IN ORDER TO PROBE THE POTENTIAL MOLECULAR MECHANISM, WE ASSUMED THE EPIGENETIC PARTICIPATION IN THE REGULATION OF PTCH1. RESULTS DEMONSTRATED THAT PTCH1 HYPERMETHYLATION IS RELATED TO THE PERSISTENT FLS ACTIVATION AND INFLAMMATION IN AA RATS. KNOCKDOWN OF MECP2 USING SMALL-INTERFERING RNA TECHNIQUE ADDED PTCH1 EXPRESSION IN AA FLSS. OUR RESULTS INDICATE THAT DNA METHYLATION MAY OFFER MOLECULE MECHANISMS, AND THE REDUCED PTCH1 METHYLATION LEVEL COULD REGULATE INFLAMMATION THROUGH KNOCKDOWN OF MECP2. GRAPHICAL ABSTRACT PTCH1 IS AN INHIBITORY PROTEIN OF THE HEDGEHOG SIGNALING PATHWAY. INCREASED EXPRESSION OF PTCH1 CAN INHIBIT THE EXPRESSION OF GLI1 AND SHH, THEREBY INHIBITING THE ACTIVATION OF HEDGEHOG SIGNALING PATHWAY. INACTIVATED HEDGEHOG SIGNALING PATHWAY INHIBITS THE SECRETION OF IL-6 AND TNF-ALPHA. MECP2 MEDIATES HYPERMETHYLATION OF PTCH1 GENE AND DECREASES THE EXPRESSION OF PTCH1 PROTEIN, THUS ACTIVATING HEDGEHOG SIGNALING PATHWAY AND INCREASING SECRETION OF IL-6 AND TNF-ALPHA. 2017 5 6758 49 WNT SIGNALING IN STEM CELL BIOLOGY AND REGENERATIVE MEDICINE. WNT FAMILY MEMBERS ARE SECRETED-TYPE GLYCOPROTEINS TO ORCHESTRATE EMBRYOGENESIS, TO MAINTAIN HOMEOSTASIS, AND TO INDUCE PATHOLOGICAL CONDITIONS. FZD1, FZD2, FZD3, FZD4, FZD5, FZD6, FZD7, FZD8, FZD9, FZD10, LRP5, LRP6, AND ROR2 ARE TRANSMEMBRANE RECEPTORS TRANSDUCING WNT SIGNALS BASED ON LIGAND-DEPENDENT PREFERENTIALITY FOR CAVEOLIN- OR CLATHRIN-MEDIATED ENDOCYTOSIS. WNT SIGNALS ARE TRANSDUCED TO CANONICAL PATHWAY FOR CELL FATE DETERMINATION, AND TO NON-CANONICAL PATHWAYS FOR REGULATION OF PLANAR CELL POLARITY, CELL ADHESION, AND MOTILITY. MYC, CCND1, AXIN2, FGF20, WISP1, JAG1, DKK1 AND GLUCAGON ARE TARGET GENES OF CANONICAL WNT SIGNALING CASCADE, WHILE CD44, VIMENTIN AND STX5 ARE TARGET GENES OF NON-CANONICAL WNT SIGNALING CASCADES. HOWEVER, TARGET GENES OF WNT SIGNALING CASCADES ARE DETERMINED IN A CONTEXT-DEPENDENT MANNER DUE TO EXPRESSION PROFILE OF TRANSCRIPTION FACTORS AND EPIGENETIC STATUS. WNT SIGNALING CASCADES NETWORK WITH NOTCH, FGF, BMP AND HEDGEHOG SIGNALING CASCADES TO REGULATE THE BALANCE OF STEM CELLS AND PROGENITOR CELLS. HERE WNT SIGNALING IN EMBRYONIC STEM CELLS, NEURAL STEM CELLS, MESENCHYMAL STEM CELLS, HEMATOPOIETIC STEM CELLS, AND INTESTINAL STEM CELLS WILL BE REVIEWED. WNT3, WNT5A AND WNT10B ARE EXPRESSED IN UNDIFFERENTIATED HUMAN EMBRYONIC STEM CELLS, WHILE WNT6, WNT8B AND WNT10B IN ENDODERM PRECURSOR CELLS. WNT6 IS EXPRESSED IN INTESTINAL CRYPT REGION FOR STEM OR PROGENITOR CELLS. TNF/ALPHA-WNT10B SIGNALING IS A NEGATIVE FEEDBACK LOOP TO MAINTAIN HOMEOSTASIS OF ADIPOSE TISSUE AND GASTROINTESTINAL MUCOSA WITH CHRONIC INFLAMMATION. RECOMBINANT WNT PROTEIN OR WNT MIMETIC (CIRCULAR PEPTIDE, SMALL MOLECULE COMPOUND, OR RNA APTAMER) IN COMBINATION WITH NOTCH MIMETIC, FGF PROTEIN, AND BMP PROTEIN OPENS A NEW WINDOW TO TISSUE ENGINEERING FOR REGENERATIVE MEDICINE. 2008 6 2437 31 EPIGENETIC SILENCING OF SONIC HEDGEHOG ELICITS ANTITUMOR IMMUNE RESPONSE AND SUPPRESSES TUMOR GROWTH BY INHIBITING THE HEDGEHOG SIGNALING PATHWAY IN METASTATIC SPINE TUMORS IN SPRAGUE-DAWLEY RATS. BACKGROUND: PATIENTS WITH METASTATIC SPINE TUMORS MAY SUFFER FROM PAIN OR NEUROLOGIC DEFICIT, AND THE DISEASE MAY BE DETECTED IN PATIENTS WITH A KNOWN MALIGNANCY. SONIC HEDGEHOG (SHH) HAS RECEIVED SPECIAL ATTENTION DUE TO ITS ROLE IN CANCERS. THEREFORE, THIS STUDY INVESTIGATED THE EFFECTS OF EPIGENETIC SILENCING OF SHH ON ANTITUMOR IMMUNE RESPONSE AND TUMOR GROWTH BY REGULATING THE HEDGEHOG (HH) SIGNALING PATHWAY IN METASTATIC SPINE TUMORS. METHODS: RAT MODELS OF METASTATIC SPINE TUMORS WERE SUCCESSFULLY ESTABLISHED. WE FIRST CALCULATED THE TUMOR VOLUME AND THE INHIBITION RATE OF TUMOR GROWTH TO INVESTIGATE THE EFFECT OF SHH ON TUMOR GROWTH. AFTERWARDS, IMMUNOHISTOCHEMISTRY WAS USED TO DETERMINE WHETHER PROLIFERATION WAS DELAYED BY SHH DEPLETION, AND THE 3-(4,5-DIMETHYLTHIAZOL-2-YL)-2,5-DIPHENYLTETRAZOLIUM BROMIDE ASSAY WAS CONDUCTED TO TEST THE CHANGES IN THE LYMPHOCYTE TRANSFORMATION RATE IN THE SPLEEN TRIGGERED BY SHH SILENCING. THEN, THE INFLUENCE OF SHH DEPLETION ON IMMUNE FUNCTION WAS INVESTIGATED. LATER, QUANTITATIVE REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION AND WESTERN BLOT ASSAY WERE PERFORMED TO EXPLORE THE HH SIGNALING PATHWAY-RELATED FACTORS. FINALLY, WE ADDED THE HH SIGNALING PATHWAY INHIBITOR, GDC-0449, TO CONFIRM THE ROLE OF THE PATHWAY IN TUMOR PROGRESSION. RESULTS: INITIALLY, WE OBSERVED THAT SHH DEPLETION WAS A NEGATIVE FACTOR FOR TUMOR GROWTH. AFTERWARDS, IT WAS REVEALED THAT EPIGENETIC SILENCING OF SHH SERVED AS AN INHIBITOR FACTOR FOR THE FUNCTION OF SPLEEN LYMPHOCYTE TRANSFORMATION AND INFLAMMATION WHILE PROMOTING ANTITUMOR IMMUNE FUNCTION. CONCLUSION: OUR PRELIMINARY RESULTS INDICATE THAT EPIGENETIC SILENCING OF SHH ELICITS AN ANTITUMOR IMMUNE RESPONSE AND SUPPRESSES TUMOR GROWTH BY INHIBITING THE HH SIGNALING PATHWAY IN METASTATIC SPINE TUMORS. 2018 7 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 8 1483 24 DKK1 IS EPIGENETICALLY DOWNREGULATED BY PROMOTER METHYLATION AND INHIBITS BILE ACID-INDUCED GASTRIC INTESTINAL METAPLASIA. DICKKOPF-RELATED PROTEIN 1 (DKK1) IS ESSENTIAL TO GASTRIC CANCER AS AN INHIBITOR OF WNT SIGNALING. GASTRIC INTESTINAL METAPLASIA (GIM) IS AN IMPORTANT PRECANCEROUS LESION OF GASTRIC CANCER THAT CAN BE ACTIVATED BY BILE ACID REFLUX AND CHRONIC INFLAMMATION. HOWEVER, THE EXACT MECHANISM OF DKK1 IN BILE ACID-INDUCED GIM HAS NOT BEEN COMPLETELY ELUCIDATED. WE AIMED TO EXPLORE THE EPIGENETIC ALTERATIONS AND BIOLOGICAL FUNCTIONS OF DKK1 IN THE DEVELOPMENT OF GIM. IN THE PRESENT STUDY, BILE ACID WAS FOUND TO INDUCE THE EXPRESSION OF INTESTINAL MARKERS IN GASTRIC EPITHELIAL CELLS, WHEREAS DKK1 WAS DOWNREGULATED IN RESPONSE TO BILE ACID STIMULATION. THE MRNA AND PROTEIN EXPRESSION LEVELS OF DKK1 WERE DECREASED IN GIM TISSUES AS EVIDENCED BY QRT-PCR AND IMMUNOHISTOCHEMICAL STAINING. SURPRISINGLY, THE METHYLATION OF THE DKK1 PROMOTER INCREASED IN GIM TISSUES, AND WE DISCOVERED 28 DIFFERENTIAL METHYLATION SITES OF THE DKK1 PROMOTER IN GIM TISSUES. BILE ACID WAS ABLE TO INDUCE THE PARTIAL METHYLATION OF THE DKK1 PROMOTER, WHILE 5-AZA COULD INCREASE DKK1 EXPRESSION AS WELL AS DECREASE INTESTINAL MARKERS EXPRESSION IN GASTRIC EPITHELIAL CELLS. IN CONCLUSION, THE PROMOTER METHYLATION AND DOWNREGULATION OF DKK1 MIGHT PLAY IMPORTANT ROLES IN THE DEVELOPMENT OF GIM, ESPECIALLY BILE ACID-INDUCED GIM. 2020 9 3642 29 INCREASED H3K4ME3 METHYLATION AND DECREASED MIR-7113-5P EXPRESSION LEAD TO ENHANCED WNT/BETA-CATENIN SIGNALING IN IMMUNE CELLS FROM PTSD PATIENTS LEADING TO INFLAMMATORY PHENOTYPE. BACKGROUND: POSTTRAUMATIC STRESS DISORDER (PTSD) IS A PSYCHIATRIC DISORDER ACCOMPANIED BY CHRONIC PERIPHERAL INFLAMMATION. WHAT TRIGGERS INFLAMMATION IN PTSD IS CURRENTLY UNCLEAR. IN THE PRESENT STUDY, WE IDENTIFIED POTENTIAL DEFECTS IN SIGNALING PATHWAYS IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) FROM INDIVIDUALS WITH PTSD. METHODS: RNASEQ (5 SAMPLES EACH FOR CONTROLS AND PTSD), CHIPSEQ (5 SAMPLES EACH) AND MIRNA ARRAY (6 SAMPLES EACH) WERE USED IN COMBINATION WITH BIOINFORMATICS TOOLS TO IDENTIFY DYSREGULATED GENES IN PBMCS. REAL TIME QRT-PCR (24 SAMPLES EACH) AND IN VITRO ASSAYS WERE EMPLOYED TO VALIDATE OUR PRIMARY FINDINGS AND HYPOTHESIS. RESULTS: BY RNA-SEQ ANALYSIS OF PBMCS, WE FOUND THAT WNT SIGNALING PATHWAY WAS UPREGULATED IN PTSD WHEN COMPARED TO NORMAL CONTROLS. SPECIFICALLY, WE FOUND INCREASED EXPRESSION OF WNT10B IN THE PTSD GROUP WHEN COMPARED TO CONTROLS. OUR FINDINGS WERE CONFIRMED USING NCBI'S GEO DATABASE INVOLVING A LARGER SAMPLE SIZE. ADDITIONALLY, IN VITRO ACTIVATION STUDIES REVEALED THAT ACTIVATED BUT NOT NAIVE PBMCS FROM CONTROL INDIVIDUALS EXPRESSED MORE IFNGAMMA IN THE PRESENCE OF RECOMBINANT WNT10B SUGGESTING THAT WNT SIGNALING PLAYED A CRUCIAL ROLE IN EXACERBATING INFLAMMATION. NEXT, WE INVESTIGATED THE MECHANISM OF INDUCTION OF WNT10B AND FOUND THAT INCREASED EXPRESSION OF WNT10B MAY RESULT FROM EPIGENETIC MODULATION INVOLVING DOWNREGULATION OF HSA-MIR-7113-5P WHICH TARGETED WNT10B. FURTHERMORE, WE ALSO OBSERVED THAT WNT10B OVEREXPRESSION WAS LINKED TO HIGHER EXPRESSION OF H3K4ME3 HISTONE MODIFICATION AROUND THE PROMOTOR OF WNT10B. ADDITIONALLY, KNOCKDOWN OF HISTONE DEMETHYLASE SPECIFIC TO H3K4ME3, USING SIRNA, LED TO INCREASED EXPRESSION OF WNT10B PROVIDING CONCLUSIVE EVIDENCE THAT H3K4ME3 INDEED CONTROLLED WNT10B EXPRESSION. CONCLUSIONS: IN SUMMARY, OUR DATA DEMONSTRATE FOR THE FIRST TIME THAT WNT SIGNALING PATHWAY IS UPREGULATED IN PBMCS OF PTSD PATIENTS RESULTING FROM EPIGENETIC CHANGES INVOLVING MICRORNA DYSREGULATION AND HISTONE MODIFICATIONS, WHICH IN TURN MAY PROMOTE THE INFLAMMATORY PHENOTYPE IN SUCH CELLS. 2020 10 1393 31 DIAGNOSTIC VALUE OF THE HYPOMETHYLATION OF THE WISP1 PROMOTER IN PATIENTS WITH HEPATOCELLULAR CARCINOMA ASSOCIATED WITH HEPATITIS B VIRUS. WNT1-INDUCIBLE SIGNALING PATHWAY PROTEIN 1 (WISP1) REGULATES CELL PROLIFERATION, DIFFERENTIATION, ADHESION, MIGRATION AND SURVIVAL. ABNORMAL WISP1 EXPRESSION IS ASSOCIATED WITH THE CARCINOGENESIS OF HEPATOCELLULAR CARCINOMA (HCC). ABERRANT DNA METHYLATION IS ONE OF THE MAJOR EPIGENETIC ALTERATIONS IN HCC. HOWEVER, THE METHYLATION STATUS OF THE WISP1 PROMOTER IS STILL UNCLEAR. WE THEREFORE AIMED TO DETERMINE THE METHYLATION STATUS OF THE WISP1 PROMOTER AND EVALUATE ITS CLINICAL VALUE IN HCC. THE STUDY ENROLLED 251 PARTICIPANTS, INCLUDING 123 PARTICIPANTS WITH HCC, 90 PARTICIPANTS WITH CHRONIC HEPATITIS B (CHB) AND 38 HEALTHY CONTROLS (HCS). WISP1 METHYLATION STATUS, MRNA LEVELS AND PLASMA SOLUBLE WISP1 WERE DETECTED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), QUANTITATIVE REAL-TIME PCR (RT-QPCR) AND ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA), RESPECTIVELY. WE FOUND THAT THE METHYLATION FREQUENCY OF WISP1 IN PATIENTS WITH HCC WAS SIGNIFICANTLY LOWER THAN THAT IN PATIENTS WITH CHB AND HCS, WHILE THE RELATIVE EXPRESSION LEVELS OF WISP1 MRNA WERE MARKEDLY HIGHER IN PATIENTS WITH HCC THAN IN PATIENTS WITH CHB AND HCS. FURTHERMORE, THE PLASMA SOLUBLE WISP1 IN PATIENTS WITH HCC WAS OBVIOUSLY LOWER THAN IN THAT IN PATIENTS WITH CHB AND HCS. ALPHA-FETOPROTEIN (AFP) IS A WIDELY RECOGNIZED BIOMARKER TO DIAGNOSE HCC WHICH LACKS ENOUGH SENSITIVITY AND SPECIFICITY. WISP1 PROMOTER METHYLATION STATUS COMBINED WITH AFP SIGNIFICANTLY IMPROVED THE DIAGNOSTIC ABILITY IN DISCRIMINATING HCC FROM CHB COMPARED WITH AFP OR WISP1 METHYLATION STATUS ALONE. IN CONCLUSION, HYPOMETHYLATION OF THE WISP1 GENE PROMOTER MAY SERVE AS A NONINVASIVE BIOMARKER FOR DETECTING HBV-ASSOCIATED HCC. 2020 11 2435 42 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 12 2379 32 EPIGENETIC REGULATION OF WNT PATHWAY ANTAGONISTS IN HUMAN GLIOBLASTOMA MULTIFORME. EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IS COMMON IN HUMAN CANCER. USING A LARGE-SCALE WHOLE-GENOME APPROACH IN AN EARLIER STUDY, THE AUTHORS IDENTIFIED EPIGENETICALLY SILENCED GENES WITH POTENTIAL TUMOR SUPPRESSOR FUNCTION IN GLIOBLASTOMA (GBM). THREE GENES IDENTIFIED IN THIS ANALYSIS-DKK1, SFRP1, AND WIF1-ARE POTENT INHIBITORS OF THE WNT SIGNAL TRANSDUCTION PATHWAY. HERE, THE AUTHORS CONFIRM DECREASED EXPRESSION OF THESE GENES IN GBM TUMOR TISSUE SAMPLES RELATIVE TO NONTUMOR BRAIN TISSUE SAMPLES USING REAL-TIME PCR. THEY THEN SHOW THAT EXPRESSION OF ALL 3 GENES IS RESTORED IN T98 GBM CELLS BY TREATMENT WITH THE HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A (TSA), BUT ONLY DKK1 EXPRESSION IS RESTORED BY TREATMENT WITH THE DEMETHYLATING AGENT 5-AZACYTIDINE. BISULFITE SEQUENCING DID NOT REVEAL SIGNIFICANT METHYLATION IN THE PROMOTER REGION OF DKK1, WHEREAS HISTONE ACETYLATION AND CHROMATIN ACCESSIBILITY INCREASED SIGNIFICANTLY FOR ALL 3 GENES AFTER TSA TREATMENT. ECTOPIC EXPRESSION OF DKK1 SIGNIFICANTLY REDUCES COLONY FORMATION AND INCREASES CHEMOTHERAPY-INDUCED APOPTOSIS IN T98 CELLS. ECTOPIC EXPRESSION OF THE CANONICAL WNT PATHWAY INHIBITORS WIF1 AND SFRP1 SHOWS A RELATIVE LACK OF RESPONSE. CHRONIC WNT3A STIMULATION ONLY PARTIALLY REVERSES GROWTH SUPPRESSION AFTER DKK1 REEXPRESSION, WHEREAS A SPECIFIC INHIBITOR OF THE JNK PATHWAY SIGNIFICANTLY REVERSES THE EFFECT OF DKK1 REEXPRESSION ON COLONY FORMATION AND APOPTOSIS IN T98 CELLS. THESE RESULTS SUPPORT A POTENTIAL GROWTH-SUPPRESSIVE FUNCTION FOR EPIGENETICALLY SILENCED DKK1 IN GBM AND SUGGEST THAT DKK1 RESTORATION COULD MODULATE WNT SIGNALING THROUGH BOTH CANONICAL AND NONCANONICAL PATHWAYS. 2010 13 6529 29 TRANSCRIPTIONAL DOWN-REGULATION OF THE WNT ANTAGONIST SFRP1 IN HAEMATOPOIETIC CELLS OF PATIENTS WITH DIFFERENT RISK TYPES OF MDS. SECRETED FRIZZLED RELATED PROTEIN 1 (SFRP1) IS AN EXTRACELLULAR ANTAGONIST OF THE WNT SIGNALLING PATHWAY THAT PLAYS AN IMPORTANT ROLE IN THE PATHOGENESIS OF SOLID TUMOURS AND HAEMATOPOIETIC MALIGNANCIES. SFRP1 HAS BEEN OBSERVED TO BE TRANSCRIPTIONALLY DOWN-REGULATED DUE TO HYPERMETHYLATION IN ACUTE AND CHRONIC LEUKAEMIA, BUT SO FAR NOT IN MYELODYSPLASTIC SYNDROME (MDS). MOREOVER, IT HAS BEEN SHOWN THAT THE EPIGENETIC INACTIVATION OF SFRP1 CORRELATES WITH AN OVEREXPRESSION OF THE WNT RECEPTOR FRIZZLED 3 (FZD3) IN ACUTE LEUKAEMIA. USING REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION (RT-PCR) WE EXAMINED MRNA EXPRESSION OF SFRP1 AND FZD3 IN BONE MARROW CELLS DERIVED FROM 121 PATIENTS WITH DIFFERENT RISK TYPES OF MDS, ACUTE MYELOID LEUKAEMIA (AML) AND ACUTE LYMPHOBLASTIC LEUKAEMIA (ALL). WE EMPLOYED PYROSEQUENCING TO QUANTIFY PROMOTER DNA METHYLATION IN MDS AND ACUTE LEUKAEMIA. WE DETECTED SIGNIFICANT LOWER MRNA TRANSCRIPTION OF SFRP1 IN MDS COMPARED TO HEALTHY INDIVIDUALS. HOWEVER, DNA SEQUENCE MUTATIONS OR FREQUENT ELEVATED DNA METHYLATION LEVELS OF THE SFRP1 PROMOTER COULD NOT BE OBSERVED IN MDS BUT IN AML AND ALL AS PREVIOUSLY REPORTED. THE EXPRESSION LEVELS OF FZD3 WERE UP-REGULATED IN BOTH ACUTE LEUKAEMIA AND MDS. OUR DATA SHOW A SIGNIFICANT TRANSCRIPTIONAL DOWN-REGULATION OF SFRP1 AS A COMMON EVENT IN AML, ALL AND - AS DEMONSTRATED FOR THE FIRST TIME - IN MDS. AN INACTIVATION OF SFRP1 AND THE TRANSCRIPTIONAL UP-REGULATION OF FZD3 SEEM TO BE ASSOCIATED WITH AN ACTIVATION OF THE WNT SIGNALLING PATHWAY IN THESE HAEMATOPOIETIC DISEASES. 2010 14 5668 31 SFRP1 EXPRESSION REGULATES WNT SIGNALING IN CHRONIC MYELOID LEUKEMIA K562 CELLS. BACKGROUND: WNT SIGNALING CASCADES PLAY IMPORTANT ROLES IN CELL FATE DECISIONS AND THEIR DEREGULATION HAS BEEN DOCUMENTED IN MANY DISEASES, INCLUDING MALIGNANT TUMORS AND LEUKEMIA. ONE MECHANISM OF ABERRANT WNT SIGNALING IS THE SILENCING OF WNT INHIBITORS THROUGH EPIGENETIC MECHANISMS. THE SFRPS ARE ONE OF THE MOST STUDIED WNT INHIBITORS; AND THE SFRP1 LOSS IS KNOWN IN MANY HEMATOLOGICAL MALIGNANCIES. THEREFORE, WE AIMED TO COMPARE THE EXPRESSION OF WNT RELATED GENES IN THE PRESENCE AND ABSENCE OF SFRP1 IN A CHRONIC MYELOID LEUKEMIA (CML) CELL LINE. OBJECTIVE: IT IS IMPORTANT TO UNDERSTAND HOW SFRP1 AND SFRP1 PERFORM THEIR EFFECTS ON CML TO DESIGN NEW AGENTS AND STRATEGIES FOR RESISTANT AND ADVANCED FORMS OF CML. MATERIALS AND METHODS: WE USED K562 CELLS, WHICH NORMALLY DO NOT EXPRESS SFRP1 AND ITS SFRP1 EXPRESSING SUBCLONE K562S. TOTAL RNA WAS ISOLATED FROM K562 AND K562S CELL LINES AND CONVERTED TO CDNA. PCR ARRAY EXPERIMENTS WERE PERFORMED USING HUMAN WNT SIGNALING PATHWAY PLUS RT2 PROFILER KIT. WNT SIGNALING PATHWAY ACTIVATION WAS STUDIED BY WESTERN BLOT FOR DOWNSTREAM SIGNALING TARGETS. RESULTS: THE WNT3, LRP6, PRICKLE1 AND BTRC EXPRESSIONS WERE SIGNIFICANTLY DECREASED IN THE PRESENCE OF SFRP1; WHILE WNT5B INCREASED. THE SFRP1 EXPRESSION INHIBITED STABILIZATION OF TOTAL BETA-CATENIN PROTEIN AND DOWNSTREAM EFFECTOR PHOSPHORYLATION OF NONCANONICAL WNT/PCP SIGNALING; WHEREAS CA2+/PKC SIGNALING REMAINED ACTIVE. CONCLUSION: THE RESULTS SUGGEST THAT SFRP1 COULD BE A PROMISING THERAPEUTIC ANTICANCER AGENT. DEFINING THESE PATHWAY INTERACTIONS IS CRUCIAL FOR DESIGNING NEW AGENTS RESISTANT AND ADVANCED FORMS OF CML. 2022 15 6757 47 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 16 6442 22 THERAPEUTIC APPROACHES IN MYELOFIBROSIS AND MYELODYSPLASTIC/MYELOPROLIFERATIVE OVERLAP SYNDROMES. THE DISCOVERY OF JAK2 (V617F) A DECADE AGO LED TO OPTIMISM FOR A RAPIDLY DEVELOPING TREATMENT REVOLUTION IN PH(-) MYELOPROLIFERATIVE NEOPLASMS. UNLIKE BCR-ABL, HOWEVER, JAK2 WAS FOUND TO HAVE A MORE HETEROGENEOUS ROLE IN CARCINOGENESIS. THEREFORE, FOR YEARS, DEVELOPMENT OF NEW THERAPIES WAS SLOW, DESPITE STANDARD TREATMENT OPTIONS THAT DID NOT ADDRESS THE OVERWHELMING SYMPTOM BURDEN IN PATIENTS WITH PRIMARY MYELOFIBROSIS (MF), POST-ESSENTIAL THROMBOCYTHEMIA MF, POST-POLYCYTHEMIA VERA MF, AND MYELODYSPLASTIC SYNDROME (MDS)/MYELOPROLIFERATIVE NEOPLASM (MPN) SYNDROMES. JAK-STAT INHIBITORS HAVE CHANGED THIS, DRASTICALLY AMELIORATING SYMPTOMS AND ULTIMATELY BEGINNING TO SHOW EVIDENCE OF IMPACT ON SURVIVAL. NOW, THE GENETIC FOUNDATIONS OF MYELOFIBROSIS AND MDS/MPN ARE RAPIDLY BEING ELUCIDATED AND CONTRIBUTING TO TARGETED THERAPY DEVELOPMENT. THIS HAS BEEN EMPOWERED THROUGH UPDATED RESPONSE CRITERIA FOR MDS/MPN AND REFINED PROGNOSTIC SCORING SYSTEMS IN THESE DISEASES. THE AIM OF THIS ARTICLE IS TO SUMMARIZE CONCISELY THE CURRENT AND RATIONALLY DESIGNED INVESTIGATIONAL THERAPEUTICS DIRECTED AT JAK-STAT, HEDGEHOG, PI3K-AKT, BONE MARROW FIBROSIS, TELOMERASE, AND ROGUE EPIGENETIC SIGNALING. THE REVOLUTION IN IMMUNOTHERAPY AND NOVEL TREATMENTS AIMED AT PREVIOUSLY UNTARGETED SIGNALING PATHWAYS PROVIDES HOPE FOR CONSIDERABLE ADVANCEMENT IN THERAPY OPTIONS FOR THOSE WITH CHRONIC MYELOID DISEASE. 2016 17 5083 32 PICKING A BONE WITH WISP1 (CCN4): NEW STRATEGIES AGAINST DEGENERATIVE JOINT DISEASE. AS THE WORLD'S POPULATION CONTINUES TO AGE, IT IS ESTIMATED THAT DEGENERATIVE JOINT DISEASE DISORDERS SUCH AS OSTEOARTHRITIS WILL IMPACT AT LEAST 130 MILLION INDIVIDUALS THROUGHOUT THE GLOBE BY THE YEAR 2050. ADVANCED AGE, OBESITY, GENETICS, GENDER, BONE DENSITY, TRAUMA, AND A POOR LEVEL OF PHYSICAL ACTIVITY CAN LEAD TO THE ONSET AND PROGRESSION OF OSTEOARTHRITIS. HOWEVER, FACTORS THAT LEAD TO DEGENERATIVE JOINT DISEASE AND INVOLVE GENDER, GENETICS, EPIGENETIC MECHANISMS, AND ADVANCED AGE ARE NOT WITHIN THE CONTROL OF AN INDIVIDUAL. FURTHERMORE, CURRENT THERAPIES INCLUDING PAIN MANAGEMENT, IMPROVED NUTRITION, AND REGULAR PROGRAMS FOR EXERCISE DO NOT LEAD TO THE RESOLUTION OF OSTEOARTHRITIS. AS A RESULT, NEW AVENUES FOR TARGETING THE TREATMENT OF OSTEOARTHRITIS ARE DESPERATELY NEEDED. WNT1 INDUCIBLE SIGNALING PATHWAY PROTEIN 1 (WISP1), A MATRICELLULAR PROTEIN AND A DOWNSTREAM TARGET OF THE WINGLESS PATHWAY WNT1, IS ONE SUCH TARGET TO CONSIDER THAT GOVERNS CELLULAR PROTECTION, STEM CELL PROLIFERATION, AND TISSUE REGENERATION IN A NUMBER OF DISORDERS INCLUDING BONE DEGENERATION. HOWEVER, INCREASED WISP1 EXPRESSION ALSO HAS BEEN ASSOCIATED WITH THE PROGRESSION OF OSTEOARTHRITIS. WISP1 HAS AN INTRICATE RELATIONSHIP WITH A NUMBER OF PROLIFERATIVE AND PROTECTIVE PATHWAYS THAT INCLUDE PHOSPHOINOSITIDE 3-KINASE (PI 3-K), PROTEIN KINASE B (AKT), NUCLEAR FACTOR KAPPA-LIGHT-CHAIN-ENHANCER OF ACTIVATED B CELLS (NF-KAPPAB), INTERLEUKIN -6 (IL-6), TRANSFORMING GROWTH FACTOR-BETA, MATRIX METALLOPROTEINASE, SMALL NON-CODING RIBONUCLEIC ACIDS (RNAS), SIRTUIN SILENT MATING TYPE INFORMATION REGULATION 2 HOMOLOG 1 (SACCHAROMYCES CEREVISIAE) (SIRT1), AND THE MECHANISTIC TARGET OF RAPAMYCIN (MTOR). TAKEN TOGETHER, THIS COMPLEX ASSOCIATION WISP1 HOLDS WITH THESE SIGNALING PATHWAYS NECESSITATES A FINE BIOLOGICAL REGULATION OF WISP1 ACTIVITY THAT CAN OFFSET THE PROGRESSION OF DEGENERATIVE JOINT DISEASE, BUT NOT LIMIT THE CELLULAR PROTECTIVE CAPABILITIES OF THE WISP1 PATHWAY. 2016 18 4501 28 MORPHOGENS AND HEPATIC STELLATE CELL FATE REGULATION IN CHRONIC LIVER DISEASE. HEPATIC STELLATE CELLS (HSC) ARE THE LIVER MESENCHYMAL CELL TYPE WHICH RESPONDS TO HEPATOCELLULAR DAMAGE AND PARTICIPATES IN WOUND HEALING. ALTHOUGH HSC MYOFIBROBLASTIC TRANS-DIFFERENTIATION (ACTIVATION) IS IMPLICATED IN EXCESSIVE EXTRACELLULAR MATRIX DEPOSITION, MOLECULAR UNDERSTANDING OF THIS PHENOTYPIC SWITCH FROM THE VIEWPOINT OF CELL FATE REGULATION IS LIMITED. RECENT STUDIES DEMONSTRATE THE ROLES OF ANTI-ADIPOGENIC MORPHOGENS (WNT, NECDIN, SHH) IN EPIGENETIC REPRESSION OF THE HSC DIFFERENTIATION GENE PPARGAMMA AS A CAUSAL EVENT IN HSC ACTIVATION. THESE MORPHOGENS HAVE POSITIVE CROSS-INTERACTIONS WHICH CONVERGE TO EPIGENETIC REPRESSION OF PPARGAMMA INVOLVING THE METHYL-CPG BINDING PROTEIN MECP2. HOWEVER, THESE MORPHOGENS EXPRESSED BY ACTIVATED HSC MAY ALSO PARTICIPATE IN CROSS-TALK BETWEEN HSC AND HEPATOBLASTS/HEPATOCYTES TO SUPPORT LIVER REGENERATION, AND THEIR ABERRANT REGULATION MAY CONTRIBUTE TO LIVER TUMORIGENESIS. IMPLICATIONS OF HSC-DERIVED MORPHOGENS IN THESE POSSIBILITIES ARE DISCUSSED. 2012 19 1142 30 CONCISE REVIEW: CHRONIC MYELOID LEUKEMIA: STEM CELL NICHE AND RESPONSE TO PHARMACOLOGIC TREATMENT. NOWADAYS, MORE THAN 90% OF PATIENTS AFFECTED BY CHRONIC MYELOID LEUKEMIA (CML) SURVIVE WITH A GOOD QUALITY OF LIFE, THANKS TO THE CLINICAL EFFICACY OF TYROSINE KINASE INHIBITORS (TKIS). NEVERTHELESS, POINT MUTATIONS OF THE ABL1 POCKET OCCURRING DURING TREATMENT MAY REDUCE BINDING OF TKIS, BEING RESPONSIBLE OF ABOUT 20% OF CASES OF RESISTANCE AMONG CML PATIENTS. IN ADDITION, THE PRESENCE OF LEUKEMIC STEM CELLS (LSCS) REPRESENTS THE MOST IMPORTANT EVENT IN LEUKEMIA PROGRESSION RELATED TO TKI RESISTANCE. LSCS EXPRESS STEM CELL MARKERS, INCLUDING ACTIVE EFFLUX PUMPS AND GENETIC AND EPIGENETIC ALTERATIONS TOGETHER WITH DEREGULATED CELL SIGNALING PATHWAYS INVOLVED IN SELF-RENEWAL, SUCH AS WNT/BETA-CATENIN, NOTCH, AND HEDGEHOG. MOREOVER, THE INTERACTION WITH THE BONE MARROW MICROENVIRONMENT, ALSO KNOWN AS HEMATOPOIETIC NICHE, MAY INFLUENCE THE PHENOTYPE OF SURROUNDING CELLS, WHICH EVADE MECHANISMS CONTROLLING CELL PROLIFERATION AND ARE LESS SENSITIVE OR FRANKLY RESISTANT TO TKIS. THIS REVIEW FOCUSES ON THE ROLE OF LSCS AND STEM CELL NICHE IN RELATION TO RESPONSE TO PHARMACOLOGICAL TREATMENTS. A LITERATURE SEARCH FROM PUBMED DATABASE WAS PERFORMED UNTIL APRIL 30, 2017, AND IT HAS BEEN ANALYZED ACCORDING TO KEYWORDS SUCH AS CHRONIC MYELOID LEUKEMIA, STEM CELL, LEUKEMIC STEM CELLS, HEMATOPOIETIC NICHE, TYROSINE KINASE INHIBITORS, AND DRUG RESISTANCE. STEM CELLS TRANSLATIONAL MEDICINE 2018;7:305-314. 2018 20 2380 35 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