1 1690 106 DUAL ROLES OF CHROMATIN REMODELING PROTEIN BRG1 IN ANGIOTENSIN II-INDUCED ENDOTHELIAL-MESENCHYMAL TRANSITION. ENDOTHELIAL-MESENCHYMAL TRANSITION (ENDMT) IS CONSIDERED ONE OF THE PROCESSES UNDERLYING TISSUE FIBROSIS BY CONTRIBUTING TO THE POOL OF MYOFIBROBLASTS. IN THE PRESENT STUDY, WE INVESTIGATED THE EPIGENETIC MECHANISM WHEREBY ANGIOTENSIN II (ANG II) REGULATES ENDMT TO PROMOTE CARDIAC FIBROSIS FOCUSING ON THE ROLE OF CHROMATIN REMODELING PROTEIN BRG1. BRG1 KNOCKDOWN OR INHIBITION ATTENUATED ANG II-INDUCED ENDMT, AS EVIDENCED BY DOWN-REGULATION OF CDH5, AN ENDOTHELIAL MARKER, AND UP-REGULATION OF COL1A2, A MESENCHYMAL MARKER, IN CULTURED VASCULAR ENDOTHELIAL CELLS. ON THE ONE HAND, BRG1 INTERACTED WITH AND WAS RECRUITED BY SP1 TO THE SNAI2 (ENCODING SLUG) PROMOTER TO ACTIVATE SNAI2 TRANSCRIPTION IN RESPONSE TO ANG II STIMULATION. ONCE ACTIVATED, SLUG BOUND TO THE CDH5 PROMOTER TO REPRESS CDH5 TRANSCRIPTION. ON THE OTHER HAND, BRG1 INTERACTED WITH AND WAS RECRUITED BY SRF TO THE COL1A2 PROMOTER TO ACTIVATE COL1A2 TRANSCRIPTION. MECHANISTICALLY, BRG1 EVICTED HISTONES FROM THE TARGET PROMOTERS TO FACILITATE THE BINDINGS OF SP1 AND SRF. FINALLY, ENDOTHELIAL CONDITIONAL BRG1 KNOCKOUT MICE (CKO) EXHIBITED A REDUCTION IN CARDIAC FIBROSIS, COMPARED TO THE WILD TYPE (WT) LITTERMATES, IN RESPONSE TO CHRONIC ANG II INFUSION. IN CONCLUSION, OUR DATA DEMONSTRATE THAT BRG1 IS A KEY TRANSCRIPTIONAL COORDINATOR PROGRAMMING ANG II-INDUCED ENDMT TO CONTRIBUTE TO CARDIAC FIBROSIS. 2020 2 922 25 CHRONIC IL-1BETA-INDUCED INFLAMMATION REGULATES EPITHELIAL-TO-MESENCHYMAL TRANSITION MEMORY PHENOTYPES VIA EPIGENETIC MODIFICATIONS IN NON-SMALL CELL LUNG CANCER. CHRONIC INFLAMMATION FACILITATES TUMOR PROGRESSION. WE DISCOVERED THAT A SUBSET OF NON-SMALL CELL LUNG CANCER CELLS UNDERWENT A GRADUALLY PROGRESSING EPITHELIAL-TO-MESENCHYMAL (EMT) PHENOTYPE FOLLOWING A 21-DAY EXPOSURE TO IL-1BETA, AN ABUNDANT PROINFLAMMATORY CYTOKINE IN THE AT-RISK FOR LUNG CANCER PULMONARY AND THE LUNG TUMOR MICROENVIRONMENTS. PATHWAY ANALYSIS OF THE GENE EXPRESSION PROFILE AND IN VITRO FUNCTIONAL STUDIES REVEALED THAT THE EMT AND EMT-ASSOCIATED PHENOTYPES, INCLUDING ENHANCED CELL INVASION, PD-L1 UPREGULATION, AND CHEMORESISTANCE, WERE SUSTAINED IN THE ABSENCE OF CONTINUOUS IL-1BETA EXPOSURE. WE REFERRED TO THIS PHENOMENON AS EMT MEMORY. UTILIZING A DOXYCYCLINE-CONTROLLED SLUG EXPRESSION SYSTEM, WE FOUND THAT HIGH EXPRESSION OF THE TRANSCRIPTION FACTOR SLUG WAS INDISPENSABLE FOR THE ESTABLISHMENT OF EMT MEMORY. HIGH SLUG EXPRESSION IN TUMORS OF LUNG CANCER PATIENTS WAS ASSOCIATED WITH POOR SURVIVAL. CHEMICAL OR GENETIC INHIBITION OF SLUG UPREGULATION PREVENTED EMT FOLLOWING THE ACUTE IL-1BETA EXPOSURE BUT DID NOT REVERSE EMT MEMORY. CHROMATIN IMMUNOPRECIPITATION AND METHYLATION-SPECIFIC PCR FURTHER REVEALED A SLUG-MEDIATED TEMPORAL REGULATION OF EPIGENETIC MODIFICATIONS, INCLUDING ACCUMULATION OF H3K27, H3K9, AND DNA METHYLATION, IN THE CDH1 (E-CADHERIN) PROMOTER FOLLOWING THE CHRONIC IL-1BETA EXPOSURE. CHEMICAL INHIBITION OF DNA METHYLATION NOT ONLY RESTORED E-CADHERIN EXPRESSION IN EMT MEMORY, BUT ALSO PRIMED CELLS FOR CHEMOTHERAPY-INDUCED APOPTOSIS. 2020 3 1632 33 DNMTS ARE INVOLVED IN TGF-BETA1-INDUCED EPITHELIAL-MESENCHYMAL TRANSITIONS IN AIRWAY EPITHELIAL CELLS. CHRONIC RHINOSINUSITIS (CRS) PATHOGENESIS IS CLOSELY RELATED TO TISSUE REMODELING, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION (EMT). EPIGENETIC MECHANISMS PLAY KEY ROLES IN EMT. DNA METHYLATION, MEDIATED BY DNA METHYLTRANSFERASES (DNMTS), IS AN EPIGENETIC MARKER THAT IS CRITICAL TO EMT. THE GOAL OF THIS STUDY WAS TO DETERMINE WHETHER DNMTS WERE INVOLVED IN TGF-BETA1-INDUCED EMT AND ELUCIDATE THE UNDERLYING MECHANISMS IN NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION AND DNMT ACTIVITY WERE QUANTIFIED. DNMT EXPRESSION WAS MEASURED USING REAL-TIME PCR (QRT-PCR) IN HUMAN CRS TISSUES. MRNA AND PROTEIN LEVELS OF DNMTS, E-CADHERIN, VIMENTIN, ALPHA-SMA, AND FIBRONECTIN WERE DETERMINED USING RT-PCR AND WESTERN BLOTTING, RESPECTIVELY. DNMT1, DNMT3A, AND DNMT3B GENE EXPRESSION WERE KNOCKED DOWN USING SIRNA TRANSFECTION. MAPK PHOSPHORYLATION AND EMT-RELATED TRANSCRIPTION FACTOR LEVELS WERE DETERMINED USING WESTERN BLOTTING. SIGNALING PATHWAYS WERE ANALYZED USING SPECIFIC INHIBITORS OF MAPK. WE DEMONSTRATED THESE DATA IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION, DNMT ACTIVITY, AND DNMT EXPRESSION INCREASED IN CRS TISSUES. DNMT EXPRESSION WAS POSITIVELY CORRELATED WITH LUND-MCKAY CT SCORES. TGF-BETA1 DOSE-DEPENDENTLY INDUCED DNMT EXPRESSION. FURTHER, 5-AZA INHIBITED TGF-BETA1-INDUCED DNMT, SNAIL, AND SLUG EXPRESSION RELATED TO EMT, AS WELL AS P38 AND JNK PHOSPHORYLATION IN A549 CELLS AND TGF-BETA1-INDUCED DNMT EXPRESSION AND EMT IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. TGF-BETA1-INDUCED DNMT EXPRESSION LEADS TO DNA METHYLATION AND EMT VIA P38, JNK, SNAIL, AND SLUG SIGNALING PATHWAYS. INHIBITION OF DNMT SUPPRESSED THE EMT PROCESS AND THEREFORE IS POTENTIALLY A CRS THERAPEUTIC STRATEGY. 2022 4 2425 25 EPIGENETIC SILENCING OF IRF1 DYSREGULATES TYPE III INTERFERON RESPONSES TO RESPIRATORY VIRUS INFECTION IN EPITHELIAL TO MESENCHYMAL TRANSITION. CHRONIC OXIDATIVE INJURY PRODUCED BY AIRWAY DISEASE TRIGGERS A TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA)-MEDIATED EPIGENETIC REPROGRAMMING KNOWN AS THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). WE OBSERVE THAT EMT SILENCES PROTECTIVE MUCOSAL INTERFERON (IFN)-I AND III PRODUCTION ASSOCIATED WITH ENHANCED RHINOVIRUS (RV) AND RESPIRATORY SYNCYTIAL VIRUS (RSV) REPLICATION. MESENCHYMAL TRANSITIONED CELLS ARE DEFECTIVE IN INDUCIBLE INTERFERON REGULATORY FACTOR 1 (IRF1) EXPRESSION BY OCCLUDING RELA AND IRF3 ACCESS TO THE PROMOTER. IRF1 IS NECESSARY FOR THE EXPRESSION OF TYPE III IFNS (IFNLS 1 AND 2/3). INDUCED BY THE EMT, ZINC FINGER E-BOX BINDING HOMEOBOX 1 (ZEB1) BINDS AND SILENCES IRF1. ECTOPIC ZEB1 IS SUFFICIENT FOR IRF1 SILENCING, WHEREAS ZEB1 KNOCKDOWN PARTIALLY RESTORES IRF1-IFNL UPREGULATION. ZEB1 SILENCES IRF1 THROUGH THE CATALYTIC ACTIVITY OF THE ENHANCER OF ZESTE 2 POLYCOMB REPRESSIVE COMPLEX 2 SUBUNIT (EZH2), FORMING REPRESSIVE H3K27(ME3) MARKS. WE OBSERVE THAT IRF1 EXPRESSION IS MEDIATED BY ZEB1 DE-REPRESSION, AND OUR STUDY DEMONSTRATES HOW AIRWAY REMODELLING/FIBROSIS IS ASSOCIATED WITH A DEFECTIVE MUCOSAL ANTIVIRAL RESPONSE THROUGH ZEB1-INITIATED EPIGENETIC SILENCING. 2017 5 6235 28 THE M(6)A DEMETHYLASE FTO PROMOTES RENAL EPITHELIAL-MESENCHYMAL TRANSITION BY REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. BACKGROUND: RENAL INTERSTITIAL FIBROSIS (RIF) IS THE MAIN PATHOLOGICAL CHANGE OF A VARIETY OF CHRONIC KIDNEY DISEASES (CKD). EPIGENETIC MODIFICATIONS OF FIBROSIS-PRONE GENES REGULATE RIF PROGRESSION. THIS STUDY AIMED TO INVESTIGATE LONG NON-CODING RNA (LNCRNA) N6-METHYLADENOSINE (M(6)A) MODIFICATION AND ITS ROLE IN REGULATING RIF PROGRESSION. METHODS: UNILATERAL URETERAL OCCLUSION (UUO) WAS EMPLOYED TO CONSTRUCT THE RIF IN VIVO MODEL; AND TGF-BETA1-TREATED HK-2 AND HKC-8 CELLS WERE USED FOR IN VITRO EXPERIMENTS. THE MRNA AND PROTEIN EXPRESSIONS WERE ASSESSED USING QRT-PCR AND WESTERN BLOT. THE PROLIFERATION AND MIGRATION WERE EVALUATED BY EDU ASSAY AND TRANSWELL ASSAY, RESPECTIVELY. IN ADDITION, LEVELS OF INFLAMMATORY CYTOKINES WERE DETERMINED BY ELISA ASSAY AND QRT-PCR. MOREOVER, LNCRNA GAS5 M(6)A LEVEL WAS DETECTED USING ME-RIP ASSAY. HE AND MASSON STAINING WERE EMPLOYED TO EVALUATE FIBROTIC LESIONS OF THE KIDNEY. RESULTS: FTO EXPRESSION WAS ELEVATED IN HK-2 AND HKC-8 CELLS AFTER TGF-BETA1 TREATMENT AND MOUSE KIDNEY TISSUE FOLLOWING UUO, AND LNCRNA GAS5 WAS DOWNREGULATED. LNCRNA GAS5 OVEREXPRESSION OR FTO SILENCING SUPPRESSED TGF-BETA1-INDUCED THE INCREASE OF EMT-RELATED PROTEINS (VIMENTIN, SNAIL AND N-CADHERIN) AND INFLAMMATORY CYTOKINES (IL-6, IL-1BETA AND TNF-ALPHA) LEVELS IN HK-2 CELLS. FTO SUPPRESSED LNCRNA GAS5 EXPRESSION BY REDUCING THE M6A MODIFICATION OF LNCRNA GAS5. ADDITIONALLY, FTO KNOCKDOWN COULD SUPPRESS EMT PROCESS AND INFLAMMATION RESPONSE INDUCED BY TGF-BETA1 AND UUO IN VITRO AND IN VIVO. AS EXPECTED, FTO KNOCKDOWN ABROGATED THE PROMOTION EFFECTS OF LNCRNA GAS5 SILENCING ON TGF-BETA1-INDUCED EMT PROCESS AND INFLAMMATION RESPONSE IN HK-2 AND HKC-8 CELLS. CONCLUSION: FTO PROMOTED EMT PROCESS AND INFLAMMATION RESPONSE THROUGH REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. 2022 6 5850 27 SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) REDUCES FIBROSIS MARKERS AND DEACTIVATES HUMAN STELLATE CELLS VIA THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). HEPATIC FIBROSIS IS KNOWN AS THE ACCUMULATION OF CONNECTIVE TISSUE SECONDARY TO CHRONIC DAMAGE TO THE LIVER. EPITHELIAL-MESENCHYMAL TRANSITION (EMT) CORRESPONDING INCREASE IN LIVER FIBROGENESIS WAS SHOWN WITH IMMUNOHISTOCHEMISTRY AND PCR-BASED STUDIES. SUBEROYLANILIDE HYDROXAMIC ACID (SAHA), A SYNTHETIC COMPOUND APPROVED AS A HISTONE DEACETYLASE INHIBITOR (HDAC) BY THE FDA TO TREAT CUTANEOUS T-CELL LYMPHOMA IS UNDER INVESTIGATION FOR THE TREATMENT OF LUNG AND RENAL FIBROSIS. EXPERIMENTAL MODELING FOR HEPATIC FIBROSIS CAN BE CONSTRUCTED WITH AN LX2 CELL LINE ISOLATED FROM HUMAN HEPATIC STELLATE CELLS (HSCS). IN THIS STUDY, WE AIMED TO INVESTIGATE THE MODULATION OF SAHA IN THE PATHOGENESIS OF LIVER FIBROSIS BY DETECTING THE LEVELS OF PROTEINS; (E-CADHERIN (E-CAD), N-CADHERIN (N-CAD), VIMENTIN (VIM), AND GENES; E-CAD, N-CAD, VIM, TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA), ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), TYPE 1 COLLAGEN (COL1A1), TYPE 3 COLLAGEN (COL3A1)) THAT PLAY A SIGNIFICANT ROLE IN EMT WITH THE LX2 CELL LINE. WE ALSO EVALUATED THE ACTION OF SAHA WITH CELL PROLIFERATION, CLONOGENIC, AND MIGRATION ASSAY. CELL PROLIFERATION WAS PERFORMED BY FLOW CYTOMETRY. ALL THE PROTEIN LEVELS WERE DETERMINED BY WESTERN BLOT ANALYSIS, AND GENE EXPRESSION LEVELS WERE MEASURED BY REAL-TIME PCR. OUR STUDY OBSERVED THAT SAHA TREATMENT DECREASED CELL VIABILITY, COLONY FORMATION AND MIGRATION IN LX2 CELLS. WE FOUND THAT SAHA INCREASED E-CAD EXPRESSION LEVEL, WHILE IT DECREASED N-CAD, VIM, COL1A1, COL3A1, ALPHA-SMA TGF-BETA GENES EXPRESSION LEVELS. SAHA DECREASED THE LEVEL OF E-CAD, N-CAD, AND VIM PROTEIN LEVELS. WE THOUGHT THAT SAHA POSSESSES POTENT ANTIFIBROTIC AND ANTI-EMT PROPERTIES IN LX2. 2021 7 6417 25 THE SWI/SNF CHROMATIN REMODELING COMPLEXES BAF AND PBAF DIFFERENTIALLY REGULATE EPIGENETIC TRANSITIONS IN EXHAUSTED CD8(+) T CELLS. CD8(+) T CELL EXHAUSTION (TEX) LIMITS DISEASE CONTROL DURING CHRONIC VIRAL INFECTIONS AND CANCER. HERE, WE INVESTIGATED THE EPIGENETIC FACTORS MEDIATING MAJOR CHROMATIN-REMODELING EVENTS IN TEX-CELL DEVELOPMENT. A PROTEIN-DOMAIN-FOCUSED IN VIVO CRISPR SCREEN IDENTIFIED DISTINCT FUNCTIONS FOR TWO VERSIONS OF THE SWI/SNF CHROMATIN-REMODELING COMPLEX IN TEX-CELL DIFFERENTIATION. DEPLETION OF THE CANONICAL SWI/SNF FORM, BAF, IMPAIRED INITIAL CD8(+) T CELL RESPONSES IN ACUTE AND CHRONIC INFECTION. IN CONTRAST, DISRUPTION OF PBAF ENHANCED TEX-CELL PROLIFERATION AND SURVIVAL. MECHANISTICALLY, PBAF REGULATED THE EPIGENETIC AND TRANSCRIPTIONAL TRANSITION FROM TCF-1(+) PROGENITOR TEX CELLS TO MORE DIFFERENTIATED TCF-1(-) TEX SUBSETS. WHEREAS PBAF ACTED TO PRESERVE TEX PROGENITOR BIOLOGY, BAF WAS REQUIRED TO GENERATE EFFECTOR-LIKE TEX CELLS, SUGGESTING THAT THE BALANCE OF THESE FACTORS COORDINATES TEX-CELL SUBSET DIFFERENTIATION. TARGETING PBAF IMPROVED TUMOR CONTROL BOTH ALONE AND IN COMBINATION WITH ANTI-PD-L1 IMMUNOTHERAPY. THUS, PBAF MAY PRESENT A THERAPEUTIC TARGET IN CANCER IMMUNOTHERAPY. 2023 8 6232 29 THE LONG NONCODING RNA MEG3 REGULATES MYOBLAST PLASTICITY AND MUSCLE REGENERATION THROUGH EPITHELIAL-MESENCHYMAL TRANSITION. FORMATION OF SKELETAL MUSCLE IS AMONG THE MOST STRIKING EXAMPLES OF CELLULAR PLASTICITY IN ANIMAL TISSUE DEVELOPMENT, AND WHILE MUSCLE PROGENITOR CELLS ARE REPROGRAMMED BY EPITHELIAL-MESENCHYMAL TRANSITION (EMT) TO MIGRATE DURING EMBRYONIC DEVELOPMENT, THE REGULATION OF EMT IN POST-NATAL MYOGENESIS REMAINS POORLY UNDERSTOOD. HERE, WE DEMONSTRATE THAT THE LONG NONCODING RNA (LNCRNA) MEG3 REGULATES EMT IN MYOBLAST DIFFERENTIATION AND SKELETAL MUSCLE REGENERATION. CHRONIC INHIBITION OF MEG3 IN C2C12 MYOBLASTS INDUCED EMT, AND SUPPRESSED CELL STATE TRANSITIONS REQUIRED FOR DIFFERENTIATION. FURTHERMORE, ADENOVIRAL MEG3 KNOCKDOWN COMPROMISED MUSCLE REGENERATION, WHICH WAS ACCOMPANIED BY ABNORMAL MESENCHYMAL GENE EXPRESSION AND INTERSTITIAL CELL PROLIFERATION. TRANSCRIPTOMIC AND PATHWAY ANALYSES OF MEG3-DEPLETED C2C12 MYOBLASTS AND INJURED SKELETAL MUSCLE REVEALED A SIGNIFICANT DYSREGULATION OF EMT-RELATED GENES, AND IDENTIFIED TGFBETA AS A KEY UPSTREAM REGULATOR. IMPORTANTLY, INHIBITION OF TGFBETAR1 AND ITS DOWNSTREAM EFFECTORS, AND THE EMT TRANSCRIPTION FACTOR SNAI2, RESTORED MANY ASPECTS OF MYOGENIC DIFFERENTIATION IN MEG3-DEPLETED MYOBLASTS IN VITRO WE FURTHER DEMONSTRATE THAT REDUCTION OF MEG3-DEPENDENT EZH2 ACTIVITY RESULTS IN EPIGENETIC ALTERATIONS ASSOCIATED WITH TGFBETA ACTIVATION. THUS, MEG3 REGULATES MYOBLAST IDENTITY TO FACILITATE PROGRESSION INTO DIFFERENTIATION. 2021 9 5860 33 SULFORAPHANE PREVENTS ANGIOTENSIN II-INDUCED CARDIOMYOPATHY BY ACTIVATION OF NRF2 THROUGH EPIGENETIC MODIFICATION. NUCLEAR FACTOR ERYTHROID 2-RELATED FACTOR (NRF2) IS AN IMPORTANT REGULATOR OF CELLULAR ANTIOXIDANT DEFENCE. WE PREVIOUSLY SHOWED THAT SFN PREVENTED ANG II-INDUCED CARDIAC DAMAGE VIA ACTIVATION OF NRF2. HOWEVER, THE UNDERLYING MECHANISM OF SFN'S PERSISTENT CARDIAC PROTECTION REMAINS UNCLEAR. THIS STUDY AIMED TO EXPLORE THE POTENTIAL OF SFN IN ACTIVATING CARDIAC NRF2 THROUGH EPIGENETIC MECHANISMS. WILD-TYPE MICE WERE INJECTED SUBCUTANEOUSLY WITH ANG II, WITH OR WITHOUT SFN. ADMINISTRATION OF CHRONIC ANG II-INDUCED CARDIAC INFLAMMATORY FACTOR EXPRESSION, OXIDATIVE DAMAGE, FIBROSIS AND CARDIAC REMODELLING AND DYSFUNCTION, ALL OF WHICH WERE EFFECTIVELY IMPROVED BY SFN TREATMENT, COUPLED WITH AN UP-REGULATION OF NRF2 AND DOWNSTREAM GENES. BISULFITE GENOME SEQUENCING AND CHROMATIN IMMUNOPRECIPITATION (CHIP) WERE PERFORMED TO DETECT THE METHYLATION LEVEL OF THE FIRST 15 CPGS AND HISTONE H3 ACETYLATION (AC-H3) STATUS IN THE NRF2 PROMOTER REGION, RESPECTIVELY. THE RESULTS SHOWED THAT SFN REDUCED ANG II-INDUCED CPG HYPERMETHYLATION AND PROMOTED AC-H3 ACCUMULATION IN THE NRF2 PROMOTER REGION, ACCOMPANIED BY THE INHIBITION OF GLOBAL DNMT AND HDAC ACTIVITY, AND A DECREASED PROTEIN EXPRESSION OF KEY DNMT AND HDAC ENZYMES. TAKEN TOGETHER, SFN EXERTS ITS CARDIOPROTECTIVE EFFECT THROUGH EPIGENETIC MODIFICATION OF NRF2, WHICH MAY PARTIALLY CONTRIBUTE TO LONG-TERM ACTIVATION OF CARDIAC NRF2. 2021 10 766 26 CCL5 SUPPRESSES KLOTHO EXPRESSION VIA P-STAT3/DNA METHYLTRANSFERASE1-MEDIATED PROMOTER HYPERMETHYLATION. BACKGROUND: ENHANCED INFLAMMATION AND REDUCED KLOTHO ARE COMMON FEATURES IN CHRONIC KIDNEY DISEASE (CKD). INFLAMMATION INDUCES DNA HYPERMETHYLATION. THIS STUDY ASSESSED THE PERFORMANCE OF INFLAMMATORY MARKER C-C MOTIF CHEMOKINE 5 (CCL5) IN EPIGENETIC REGULATION OF KLOTHO EXPRESSION. METHODS: FIFTY CKD PATIENTS AND 25 MATCHED CONTROLS WERE ENROLLED, AND SERUM CCL5 LEVEL, SKLOTHO LEVEL, AND DNA METHYLATION WERE EVALUATED IN THESE SUBJECTS. A RENAL INTERSTITIAL FIBROSIS (RIF) MODEL WITH CKD WAS INDUCED IN MICE VIA UNILATERAL URETERAL OBSTRUCTION (UUO) IN VIVO AND HUMAN PROXIMAL TUBULAR EPITHELIAL (HK-2) CELLS TREATED WITH CCL5 IN VITRO. 5-AZA-2'-DEOXYCYTIDINE (5-AZA), A DNA METHYLTRANSFERASE INHIBITOR WAS GIVEN TO UUO MICE. HEMATOXYLIN AND EOSIN (HE) AND MASSON TRICHROME STAINING WERE ADOPTED TO EVALUATE RENAL PATHOLOGICAL CHANGES. METHYLATION-SPECIFIC PCR WAS PERFORMED TO ASSESS DNA METHYLATION OF KLOTHO PROMOTER IN THE PERIPHERAL BLOOD LEUCOCYTES (PBLS) FROM CKD PATIENTS AND OBSTRUCTIVE KIDNEY FROM UUO MICE. CCL5, KLOTHO, AND DNA METHYLTRANSFERASES (DNMTS) WERE DETERMINED BY ELISAS, IMMUNOFLUORESCENCE, OR WESTERN BLOTTING. HK-2 CELLS WERE EXPOSED TO CCL5 WITH OR WITHOUT 5-AZA AND STATTIC, A P-SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) INHIBITOR, AND EXPRESSIONS OF P-STAT3, DNMT1, AND KLOTHO WERE DETERMINED BY WESTERN BLOTTING. RESULTS: CCL5 UPREGULATION CONCOMITANT WITH KLOTHO DOWNREGULATION IN SERUM AND GLOBAL DNA METHYLATION IN PBLS WERE OBSERVED IN CKD SAMPLES. UUO CONTRIBUTED TO SEVERE RENAL INTERSTITIAL FIBROSIS AND ENHANCED EXPRESSIONS OF FIBROTIC MARKERS. MOREOVER, UUO INCREASED THE CCL5 LEVEL, INDUCED KLOTHO PROMOTER METHYLATION, SUPPRESSED KLOTHO LEVEL, ACTIVATED P-STAT3 SIGNALING, AND UPREGULATED DNMT1 LEVEL. A SIMILAR OBSERVATION WAS MADE IN HK-2 CELLS TREATED WITH CCL5. MORE IMPORTANTLY, 5-AZA INHIBITED UUO-INDUCED KLOTHO HYPERMETHYLATION, REVERSED KLOTHO, DOWNREGULATED P-STAT3 EXPRESSIONS, AND AMELIORATED RIF IN VIVO. THE CONSISTENT FINDINGS IN VITRO WERE ALSO OBTAINED IN HK-2 CELLS EXPOSED TO 5-AZA AND STATTIC. CONCLUSION: THE CCL5/P-STAT3/DNMT1 AXIS IS IMPLICATED IN EPIGENETIC REGULATION OF KLOTHO EXPRESSION IN CKD. THIS STUDY PROVIDES NOVEL THERAPEUTIC POSSIBILITIES FOR REVERSAL OF KLOTHO SUPPRESSION BY CKD. 2022 11 4260 28 METTL3-MEDIATED M6A MODIFICATION OF SIRT1 MRNA INHIBITS PROGRESSION OF ENDOMETRIOSIS BY CELLULAR SENESCENCE ENHANCING. BACKGROUND: ENDOMETRIOSIS (EMS), THE ECTOPIC PLANTING OF FUNCTIONAL ENDOMETRIUM OUTSIDE OF THE UTERUS, IS A LEADING CAUSE OF INFERTILITY AND PELVIC PAIN. AS A FUNDAMENTAL MRNA MODIFICATION, N6-METHYLADENOSINE (M6A) PARTICIPATES IN VARIOUS PATHOLOGICAL PROCESSES. HOWEVER, THE ROLE OF M6A RNA MODIFICATION IN ENDOMETRIOSIS REMAINS UNCLEAR. THE PRESENT STUDY EXPLORES METTL3-MEDIATED M6A MODIFICATION AND THE MECHANISMS INVOLVED IN ENDOMETRIOSIS. METHODS: THE DOMINANT M6A REGULATORS IN EMS WERE ANALYSED USING RT?PCR. CANDIDATE TARGETS AND POSSIBLE MECHANISMS OF METTL3 WERE ASSESSED BY M6A-MRNA EPITRANSCRIPTOMIC MICROARRAY AND RNA SEQUENCING. A PRIMARY ESCS MODEL WAS EMPLOYED TO VERIFY THE EFFECT OF METTL3 ON M6A MODIFICATION OF SIRT1 MRNA, AND THE MECHANISM WAS ELUCIDATED BY RT?PCR, WESTERN BLOTTING, MERIP, AND RIP ASSAYS. CCK-8 VIABILITY ASSAYS, TRANSWELL INVASION ASSAYS, EDU PROLIFERATION ASSAYS, WOUND HEALING MIGRATION ASSAYS, AND SENESCENCE-ASSOCIATED BETA-GALACTOSIDASE STAINING WERE PERFORMED TO ILLUMINATE THE POTENTIAL BIOLOGICAL MECHANISM OF METTL3 AND SIRT1 IN ESCS IN VITRO. AN IN VIVO PGRCRE/ + METTL3 -/- FEMALE HOMOZYGOUS MOUSE MODEL AND A NUDE MOUSE XENOGRAFT MODEL WERE EMPLOYED TO FURTHER INVESTIGATE THE PHYSIOLOGIC CONSEQUENCES OF METTL3-MEDIATED M6A ALTERATION ON EMS. RESULTS: OUR DATA SHOW THAT DECREASED METTL3 EXPRESSION SIGNIFICANTLY DOWNREGULATES M6A RNA METHYLATION LEVELS IN ESCS. SILENCING M6A MODIFICATIONS MEDIATED BY METTL3 ACCELERATES ESCS VIABILITY, PROLIFERATION, MIGRATION, AND INVASION IN VITRO. THE M6A READER PROTEIN YTHDF2 BINDS TO M6A MODIFICATIONS TO INDUCE THE DEGRADATION OF SIRT1 MRNA. SIRT1/FOXO3A SIGNALLING PATHWAY ACTIVATION IS SUBSEQUENTLY INHIBITED, PROMOTING THE CELLULAR SENESCENCE OF ESCS AND INHIBITING THE ECTOPIC IMPLANTATION OF ESCS IN VITRO AND IN VIVO. CONCLUSIONS: OUR FINDINGS DEMONSTRATE THAT METTL3-MEDIATED M6A METHYLATION EPIGENETICALLY REGULATES THE ECTOPIC IMPLANTATION OF ESCS, RESULTING IN THE PROGRESSION OF ENDOMETRIOSIS. OUR STUDY ESTABLISHES METTL3-YTHDF2-SIRT1/FOXO3A AS A CRITICAL AXIS AND POTENTIAL MECHANISM IN ENDOMETRIOSIS. 2023 12 4159 36 MECP2 CONTROLS AN EPIGENETIC PATHWAY THAT PROMOTES MYOFIBROBLAST TRANSDIFFERENTIATION AND FIBROSIS. BACKGROUND & AIMS: MYOFIBROBLAST TRANSDIFFERENTIATION GENERATES HEPATIC MYOFIBROBLASTS, WHICH PROMOTE LIVER FIBROGENESIS. THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPARGAMMA) IS A NEGATIVE REGULATOR OF THIS PROCESS. WE INVESTIGATED EPIGENETIC REGULATION OF PPARGAMMA AND MYOFIBROBLAST TRANSDIFFERENTIATION. METHODS: CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAYS ASSESSED THE BINDING OF METHYL-CPG BINDING PROTEIN 2 (MECP2) TO PPARGAMMA AND CHROMATIN MODIFICATIONS THAT SILENCE THIS GENE. MECP2(-/Y) MICE AND AN INHIBITOR (DZNEP) OF THE EPIGENETIC REGULATORY PROTEIN EZH2 WERE USED IN THE CARBON TETRACHLORIDE MODEL OF LIVER FIBROSIS. LIVER TISSUES FROM MICE WERE ASSESSED BY HISTOLOGIC ANALYSIS; MARKERS OF FIBROSIS WERE MEASURED BY QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR). REVERSE TRANSCRIPTION PCR DETECTED CHANGES IN EXPRESSION OF THE MICRORNA MIR132 AND ITS TARGET, ELONGATED TRANSCRIPTS OF MECP2. MYOFIBROBLASTS WERE TRANSFECTED WITH MIR132; PPARGAMMA AND MECP2 EXPRESSIONS WERE ANALYZED BY QPCR OR IMMUNOBLOTTING. RESULTS: MYOFIBROBLAST TRANSDIFFERENTIATION OF HEPATIC STELLATE CELLS IS CONTROLLED BY A COMBINATION OF MECP2, EZH2, AND MIR132 IN A RELAY PATHWAY. THE PATHWAY IS ACTIVATED BY DOWN-REGULATION OF MIR132, RELEASING THE TRANSLATIONAL BLOCK ON MECP2. MECP2 IS RECRUITED TO THE 5' END OF PPARGAMMA, WHERE IT PROMOTES METHYLATION BY H3K9 AND RECRUITS THE TRANSCRIPTION REPRESSOR HP1ALPHA. MECP2 ALSO STIMULATES EXPRESSION OF EZH2 AND METHYLATION OF H3K27 TO FORM A REPRESSIVE CHROMATIN STRUCTURE IN THE 3' EXONS OF PPARGAMMA. GENETIC AND PHARMACOLOGIC DISRUPTIONS OF MECP2 OR EZH2 REDUCED THE FIBROGENIC CHARACTERISTICS OF MYOFIBROBLASTS AND ATTENUATED FIBROGENESIS. CONCLUSIONS: LIVER FIBROSIS IS REGULATED BY AN EPIGENETIC RELAY PATHWAY THAT INCLUDES MECP2, EZH2, AND MIR132. REAGENTS THAT INTERFERE WITH THIS PATHWAY MIGHT BE DEVELOPED TO REDUCE FIBROGENESIS IN CHRONIC LIVER DISEASE. 2010 13 673 35 BRAHMA-RELATED GENE 1 (BRG1) EPIGENETICALLY REGULATES CAM ACTIVATION DURING HYPOXIC PULMONARY HYPERTENSION. AIMS: ESTABLISHMENT OF AN INFLAMMATORY MILIEU FOLLOWING ELEVATED LEUKOCYTE ADHESION TO THE VASCULAR ENDOTHELIUM, WHICH IS MEDIATED BY TRANSCRIPTIONAL ACTIVATION OF CELL ADHESION MOLECULES (CAMS), CONTRIBUTES TO THE PATHOGENESIS OF CHRONIC HYPOXIA-INDUCED PULMONARY HYPERTENSION (HPH). THE EPIGENETIC SWITCH THAT DICTATES CAM TRANSACTIVATION IN RESPONSE TO HYPOXIA IN ENDOTHELIAL CELLS LEADING UP TO HPH IS NOT FULLY APPRECIATED. METHODS AND RESULTS: WE REPORT HERE THAT BRAHMA-RELATED GENE 1 (BRG1) AND BRAHMA (BRM), TWO CATALYTIC COMPONENTS OF THE MAMMALIAN CHROMATIN REMODELLING COMPLEX, WERE INDUCED IN CULTURED ENDOTHELIAL CELLS CHALLENGED WITH HYPOXIA IN VITRO AS WELL AS IN PULMONARY ARTERIES IN AN ANIMAL MODEL OF HPH. OVER-EXPRESSION OF BRG1/BRM ENHANCED, WHILE THE DEPLETION OF BRG1/BRM ATTENUATED, CAM TRANSACTIVATION AND ADHESION OF LEUKOCYTES. ENDOTHELIAL-SPECIFIC DELETION OF BRG1/BRM AMELIORATED VASCULAR INFLAMMATION AND HPH IN MICE. CHROMATIN IMMUNOPRECIPITATION (CHIP) AND RE-CHIP ASSAYS REVEALED THAT HYPOXIA UP-REGULATED THE OCCUPANCIES OF BRG1 AND BRM ON CAM PROMOTERS IN A NUCLEAR FACTOR KAPPAB (NF-KAPPAB) -DEPENDENT MANNER. FINALLY, BRG1 AND BRM ACTIVATED CAM TRANSCRIPTION BY ALTERING THE CHROMATIN STRUCTURE SURROUNDING THE CAM PROMOTERS. CONCLUSION: OUR DATA SUGGEST THAT BRG1 PROVIDES THE CRUCIAL EPIGENETIC LINK TO HYPOXIA-INDUCED CAM INDUCTION AND LEUKOCYTE ADHESION THAT ENGENDERS ENDOTHELIAL MALFUNCTION AND PATHOGENESIS OF HPH. AS SUCH, TARGETING BRG1 IN ENDOTHELIAL CELLS MAY YIELD PROMISING STRATEGIES IN THE INTERVENTION AND/OR PREVENTION OF HPH. 2013 14 6134 16 THE EPIGENETICALLY-REGULATED MIR-34A TARGETING C-SRC SUPPRESSES RAF/MEK/ERK SIGNALING PATHWAY IN K-562 CELLS. PREVIOUS REPORTS SHOW THAT MIR-34A SUPPRESSED K-562 CELL PROLIFERATION AND CONTRIBUTED TO MEGAKARYOCYTIC DIFFERENTIATION OF K-562 CELLS. HERE, WE REPORTED THAT MIR-34A, A TUMOR SUPPRESSOR GENE, IS DOWN-REGULATED IN THE K-562 CELLS AND CHRONIC MYELOID LEUKEMIA (CML) PATIENTS DUE TO ABERRANT DNA HYPERMETHYLATION. C-SRC IS A TARGET OF MIR-34A. RESTORING MIR-34A EXPRESSION RESULTED IN DOWN-REGULATION OF C-SRC AND PHOSPHORYLATED (TYR416) C-SRC PROTEIN IN K-562 CELLS, WHICH CONSEQUENTLY TRIGGERED SUPPRESSION OF THE RAF/MEK/ERK SIGNALING PATHWAY TO DECREASE CELL PROLIFERATION. 2017 15 3175 29 H2AX PHOSPHORYLATION REGULATED BY P38 IS INVOLVED IN BIM EXPRESSION AND APOPTOSIS IN CHRONIC MYELOGENOUS LEUKEMIA CELLS INDUCED BY IMATINIB. INCREASING EVIDENCE SUGGESTS THAT HISTONE H2AX PLAYS A CRITICAL ROLE IN REGULATION OF TUMOR CELL APOPTOSIS AND ACTS AS A NOVEL HUMAN TUMOR SUPPRESSOR PROTEIN. HOWEVER, THE ACTION OF H2AX IN CHRONIC MYELOGENOUS LEUKEMIA (CML) CELLS IS UNKNOWN. THE DETAILED MECHANISM AND EPIGENETIC REGULATION BY H2AX REMAIN ELUSIVE IN CANCER CELLS. HERE, WE REPORT THAT H2AX WAS INVOLVED IN APOPTOSIS OF CML CELLS. OVEREXPRESSION OF H2AX INCREASED APOPTOTIC SENSITIVITY OF CML CELLS (K562) INDUCED BY IMATINIB. HOWEVER, OVEREXPRESSION OF SER139-MUTATED H2AX (BLOCKING PHOSPHORYLATION) DECREASED SENSITIVITY OF K562 CELLS TO APOPTOSIS. SIMILARLY, KNOCKDOWN OF H2AX MADE K562 CELLS RESISTANT TO APOPTOTIC INDUCTION. THESE RESULTS REVEALED THAT THE FUNCTION OF H2AX INVOLVED IN APOPTOSIS IS STRICTLY RELATED TO ITS PHOSPHORYLATION (SER139). OUR DATA FURTHER INDICATED THAT IMATINIB MAY STIMULATE MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) FAMILY MEMBER P38, AND H2AX PHOSPHORYLATION FOLLOWED A SIMILAR TIME COURSE, SUGGESTING A PARALLEL RESPONSE. H2AX PHOSPHORYLATION CAN BE BLOCKED BY P38 SIRNA OR ITS INHIBITOR. THESE DATA DEMONSTRATED THAT H2AX PHOSPHORYLATION WAS REGULATED BY P38 MAPK PATHWAY IN K562 CELLS. HOWEVER, THE P38 MAPK DOWNSTREAM, MITOGEN- AND STRESS-ACTIVATED PROTEIN KINASE-1 AND -2, WHICH PHOSPHORYLATED HISTONE H3, WERE NOT REQUIRED FOR H2AX PHOSPHORYLATION DURING APOPTOSIS. FINALLY, WE PROVIDED EPIGENETIC EVIDENCE THAT H2AX PHOSPHORYLATION REGULATED APOPTOSIS-RELATED GENE BIM EXPRESSION. BLOCKING OF H2AX PHOSPHORYLATION INHIBITED BIM GENE EXPRESSION. TAKEN TOGETHER, THESE DATA DEMONSTRATED THAT H2AX PHOSPHORYLATION REGULATED BY P38 IS INVOLVED IN BIM EXPRESSION AND APOPTOSIS IN CML CELLS INDUCED BY IMATINIB. 2014 16 4696 26 NF-KAPPAB REPRESSES RETINOIC ACID RECEPTOR-MEDIATED GPRC5A TRANSACTIVATION IN LUNG EPITHELIAL CELLS TO PROMOTE NEOPLASIA. CHRONIC INFLAMMATION IS ASSOCIATED WITH LUNG TUMORIGENESIS, IN WHICH NF-KAPPAB-MEDIATED EPIGENETIC REGULATION PLAYS A CRITICAL ROLE. LUNG TUMOR SUPPRESSOR G PROTEIN-COUPLED RECEPTOR, FAMILY C, MEMBER 5A (GPRC5A), IS REPRESSED IN MOST NON-SMALL CELL LUNG CANCER (NSCLC); HOWEVER, THE MECHANISMS REMAIN UNCLEAR. HERE, WE SHOW THAT NF-KAPPAB ACTS AS A TRANSCRIPTIONAL REPRESSOR IN SUPPRESSION OF GPRC5A. NF-KAPPAB INDUCED GPRC5A REPRESSION BOTH IN VITRO AND IN VIVO. INTRIGUINGLY, TRANSACTIVATION OF NF-KAPPAB DOWNSTREAM TARGETS WAS NOT REQUIRED, BUT THE TRANSACTIVATION DOMAIN OF RELA/P65 WAS REQUIRED FOR GPRC5A REPRESSION. NF-KAPPAB DID NOT BIND TO ANY POTENTIAL CIS-ELEMENT IN THE GPRC5A PROMOTER. INSTEAD, P65 WAS COMPLEXED WITH RETINOIC ACID RECEPTOR ALPHA/BETA (RARALPHA/BETA) AND RECRUITED TO THE RA RESPONSE ELEMENT SITE AT THE GPRC5A PROMOTER, RESULTING IN DISRUPTED RNA POLYMERASE II COMPLEXING AND SUPPRESSED TRANSCRIPTION. NOTABLY, PHOSPHORYLATION ON SERINE 276 OF P65 WAS REQUIRED FOR INTERACTION WITH RARALPHA/BETA AND REPRESSION OF GPRC5A. MOREOVER, NF-KAPPAB-MEDIATED EPIGENETIC REPRESSION WAS THROUGH SUPPRESSION OF ACETYLATED HISTONE H3K9 (H3K9AC), BUT NOT DNA METHYLATION OF THE CPG ISLANDS, AT THE GPRC5A PROMOTER. CONSISTENTLY, A HISTONE DEACETYLASE INHIBITOR, BUT NOT DNA METHYLATION INHIBITOR, RESTORED GPRC5A EXPRESSION IN NSCLC CELLS. THUS, NF-KAPPAB INDUCES TRANSCRIPTIONAL REPRESSION OF GPRC5A VIA A COMPLEX WITH RARALPHA/BETA AND MEDIATES EPIGENETIC REPRESSION VIA SUPPRESSION OF H3K9AC. 2023 17 2479 24 EPIGENETIC UPREGULATION OF CXCL12 EXPRESSION MEDIATES ANTITUBULIN CHEMOTHERAPEUTICS-INDUCED NEUROPATHIC PAIN. CLINICALLY, MICROTUBULE-TARGETED AGENTS-INDUCED NEUROPATHIC PAIN HAMPERS CHEMOTHERAPEUTICS FOR PATIENTS WITH CANCER. HERE, WE FOUND THAT APPLICATION OF PACLITAXEL OR VINCRISTINE INCREASED THE PROTEIN AND MRNA EXPRESSION OF CXCL12 AND FREQUENCY AND AMPLITUDE OF MINIATURE EXCITATORY POST SYNAPTIC CURRENTS (MEPSCS) IN SPINAL DORSAL HORN NEURONS. SPINAL LOCAL APPLICATION OF CXCL12 INDUCED THE LONG-TERM POTENTIATION OF NOCICEPTIVE SYNAPTIC TRANSMISSION AND INCREASED THE AMPLITUDE OF MEPSCS. INHIBITION OF CXCL12 USING THE TRANSGENIC MICE (CXCL12) OR NEUTRALIZING ANTIBODY OR SIRNA AMELIORATED THE MEPSC'S ENHANCEMENT AND MECHANICAL ALLODYNIA. IN ADDITION, PACLITAXEL AND VINCRISTINE BOTH COULD INCREASE THE PHOSPHORYLATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) AND THE ACETYLATION OF HISTONE H4 IN THE CXCL12-EXPRESSING NEURONS. IMMUNOPRECIPITATION AND CHROMATIN IMMUNOPRECIPITATION ASSAYS DEMONSTRATED THAT ANTITUBULIN CHEMOTHERAPEUTICS INCREASED THE BINDING OF STAT3 TO THE CXCL12 GENE PROMOTER AND THE INTERACTION BETWEEN STAT3 AND P300, AND CONTRIBUTED TO THE ENHANCED TRANSCRIPTION OF CXCL12 BY INCREASING THE ACETYLATION OF HISTONE H4 IN CXCL12 GENE PROMOTER. INHIBITION OF STAT3 BY INTRATHECAL INJECTION OF ADENO-ASSOCIATED VIRUS ENCODING CRE AND GREEN FLUORESCENT PROTEIN INTO STAT3 MICE OR INHIBITOR S3I-201 INTO RATS SUPPRESSED THE CXCL12 UPSURGE BY DECREASING THE ACETYLATION OF HISTONE H4. FINALLY, BLOCKADE OF CXCR4 BUT NOT CXCR7 AMELIORATED THE PACLITAXEL- OR VINCRISTINE-INDUCED MECHANICAL ALLODYNIA. TOGETHER, THESE RESULTS SUGGESTED THAT ENHANCED INTERACTION BETWEEN STAT3 AND P300 MEDIATED THE EPIGENETIC UPREGULATION OF CXCL12 IN DORSAL HORN NEURONS, WHICH CONTRIBUTED TO THE ANTITUBULIN CHEMOTHERAPEUTICS-INDUCED PERSISTENT PAIN. 2017 18 2863 24 FUNCTION OF DNA METHYLTRANSFERASE 3A IN LEAD (PB(2+) )-INDUCED CYCLOOXYGENASE-2 GENE. LEAD IONS (PB(2+) ) ARE TOXIC INDUSTRIAL POLLUTANTS ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES IN HUMANS AND ANIMALS. PREVIOUSLY, WE FOUND THAT PB(2+) IONS INDUCE COX-2 GENE EXPRESSION VIA THE EGF RECEPTOR/NUCLEAR FACTOR-KAPPAB SIGNAL TRANSDUCTION PATHWAY IN EPIDERMOID CARCINOMA CELL LINE A431. IN THIS STUDY, TO SEE WHETHER PB(2+) IONS AFFECT COX-2 EXPRESSION BY EPIGENETIC MECHANISMS, WE LOOKED AT THE MRNAS OF DNA METHYLTRANSFERASES (DNMTS) USING REAL-TIME PCR OF TOTAL RNA FROM THESE CELLS. CELLS EXPOSED TO PB(2+) HAD LOW LEVELS OF DNMT3A MRNA, WHEREAS THE LEVELS OF DNMT1 AND DNMT3B MRNAS REMAINED UNCHANGED. PRETREATMENT OF CELLS WITH DNMT INHIBITOR 5-AZA-2'-DEOXYCYTIDINE (5 MUM) FOLLOWED BY PB(2+) (1 MUM) SIGNIFICANTLY INCREASED LEVELS OF COX-2 MRNA COMPARED WITH CELLS TREATED WITH PB(2+) ALONE. OVEREXPRESSION OF TUMOR SUPPRESSOR GENE RB CORRELATED WITH AN INCREASE IN COX-2 MRNA AND A DECREASE IN DNMT3A MRNA. CONVERSELY, OVEREXPRESSION OF TRANSCRIPTION FACTOR E2F1 CORRELATED WITH A DECREASE IN COX-2 MRNA AND AN INCREASE IN DMNT3A MRNA. PRETREATMENT WITH EGFR INHIBITORS AG1478 AND PD153035 SIGNIFICANTLY LIMITED PB(2+) -INDUCED REDUCTION IN DNMT3A MRNA. IN ADDITION, GENE KNOCKDOWN OF DNMT3A WITH SHORT HAIRPIN RNA CORRELATED WITH INCREASED COX-2 MRNA INDUCED BY PB(2+) . OUR FINDINGS SUGGEST PB(2+) IONS INDUCE COX-2 EXPRESSION INDIRECTLY BY REDUCING DNMT3A METHYLATION OF THE COX-2 PROMOTER VIA TRANSCRIPTION FACTORS RB AND E2F1. 2015 19 3216 27 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 20 1730 16 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