1 6614 150 ULTRAVIOLET IRRADIATION INDUCES KERATINOCYTE PROLIFERATION AND EPIDERMAL HYPERPLASIA THROUGH THE ACTIVATION OF THE EPIDERMAL GROWTH FACTOR RECEPTOR. CHRONIC EXPOSURE TO ULTRAVIOLET (UV) IRRADIATION INDUCES SKIN CANCER, IN PART, THROUGH EPIGENETIC MECHANISMS THAT RESULT IN THE DEREGULATION OF CELL PROLIFERATION. UV IRRADIATION ALSO RAPIDLY ACTIVATES THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR). SINCE EGFR ACTIVATION IS STRONGLY MITOGENIC IN MANY CELL TYPES INCLUDING KERATINOCYTES OF THE SKIN, WE HYPOTHESIZED THAT UV-INDUCED CUTANEOUS PROLIFERATION RESULTS FROM EGFR ACTIVATION. THE ROLE OF EGFR ACTIVATION IN THE RESPONSE OF THE SKIN TO UV WAS DETERMINED USING EGFR-NULL AND EGFR-WILD-TYPE SKIN GRAFTED ONTO ATHYMIC NUDE MOUSE HOSTS, BECAUSE EGFR-NULL MICE SURVIVE ONLY A FEW DAYS AFTER BIRTH. EGFR WAS RAPIDLY ACTIVATED IN MOUSE EPIDERMIS FOLLOWING EXPOSURE TO UV, AS DETECTED BY THE PHOSPHORYLATION OF EGFR ON TYROSINE RESIDUES 992, 1045, 1068 AND 1173. UV INDUCED EPIDERMAL HYPERPLASIA IN EGFR-WILD-TYPE SKIN BETWEEN 48 AND 72 H POST-UV. HOWEVER, NO EPIDERMAL HYPERPLASIA OCCURRED IN EGFR-NULL SKIN. BASELINE CELL PROLIFERATION WAS SIMILAR IN SKIN GRAFTS OF BOTH GENOTYPES. HOWEVER, UV EXPOSURE INCREASED CELL PROLIFERATION, AS MEASURED BY KI67 IMMUNOHISTOCHEMISTRY AND PROLIFERATING CELL NUCLEAR ANTIGEN IMMUNOBLOTTING, MAXIMALLY AT 48 H TO A LEVEL MORE THAN THREE TIMES HIGHER IN WILD-TYPE COMPARED WITH EGFR-NULL SKIN. APOPTOTIC CELL DEATH, AS MEASURED BY TERMINAL DEOXYNUCLEOTIDYL TRANSFERASE BIOTIN-DUTP NICK END LABELING (TUNEL) ANALYSIS, WAS ALSO INCREASED IN UV-EXPOSED EGFR-NULL SKIN WHEN COMPARED WITH WILD-TYPE 1-2 DAYS POST-UV. THESE CHANGES IN CELLULAR HOMEOSTASIS AFTER UV WERE ACCOMPANIED BY INCREASED CYCLIN D EXPRESSION IN WILD-TYPE BUT NOT EGFR-NULL SKIN AND INCREASED EXPRESSION OF P53 AND THE CYCLIN-DEPENDENT KINASE (CDK) INHIBITOR P21WAF1 IN EGFR-NULL SKIN WHEN COMPARED WITH WILD-TYPE. COLLECTIVELY, THESE RESULTS DEMONSTRATE THAT THE UV-INDUCED ACTIVATION OF EGFR AUGMENTS KERATINOCYTE PROLIFERATION AND SUPPRESSES APOPTOSIS, LEADING TO EPIDERMAL HYPERPLASIA, ASSOCIATED WITH INCREASED G1 CYCLIN EXPRESSION AND SUPPRESSION OF CDK INHIBITOR EXPRESSION. 2006 2 6011 30 THE ANTIRESECTION ACTIVITY OF THE X PROTEIN ENCODED BY HEPATITIS VIRUS B. CHRONIC INFECTION OF HEPATITIS B VIRUS (HBV) IS ASSOCIATED WITH AN INCREASED INCIDENCE OF HEPATOCELLULAR CARCINOMA (HCC). HBV ENCODES AN ONCOPROTEIN, HEPATITIS B X PROTEIN (HBX), THAT IS CRUCIAL FOR VIRAL REPLICATION AND INTERFERES WITH MULTIPLE CELLULAR ACTIVITIES INCLUDING GENE EXPRESSION, HISTONE MODIFICATIONS, AND GENOMIC STABILITY. TO DATE, IT REMAINS UNCLEAR HOW DISRUPTION OF THESE ACTIVITIES CONTRIBUTES TO HEPATOCARCINOGENESIS. HERE, WE REPORT THAT HBV EXHIBITS ANTIRESECTION ACTIVITY BY DISRUPTING DNA END RESECTION, THUS IMPAIRING THE INITIAL STEPS OF HOMOLOGOUS RECOMBINATION (HR). THIS ANTIRESECTION ACTIVITY OCCURS IN PRIMARY HUMAN HEPATOCYTES UNDERGOING A NATURAL VIRAL INFECTION-REPLICATION CYCLE AS WELL AS IN CELLS WITH INTEGRATED HBV GENOMES. AMONG THE SEVEN HBV-ENCODED PROTEINS, WE IDENTIFIED HBX AS THE SOLE VIRAL FACTOR THAT INHIBITS RESECTION. BY DISRUPTING AN EVOLUTIONARILY CONSERVED CULLIN4A-DAMAGE-SPECIFIC DNA BINDING PROTEIN 1-RING TYPE OF E3 LIGASE, CRL4(WDR70) , THROUGH ITS H-BOX, WE SHOW THAT HBX INHIBITS H2B MONOUBIQUITYLATION AT LYSINE 120 AT DOUBLE-STRAND BREAKS, THUS REDUCING THE EFFICIENCY OF LONG-RANGE RESECTION. WE FURTHER SHOW THAT DIRECTLY IMPAIRING H2B MONOUBIQUITYLATION ELICITED TUMORIGENESIS UPON ENGRAFTMENT OF DEFICIENT CELLS IN ATHYMIC MICE, CONFIRMING THAT THE IMPAIRMENT OF CRL4(WDR70) FUNCTION BY HBX IS SUFFICIENT TO PROMOTE CARCINOGENESIS. FINALLY, WE DEMONSTRATE THAT LACK OF H2B MONOUBIQUITYLATION IS MANIFEST IN HUMAN HBV-ASSOCIATED HCC WHEN COMPARED WITH HBV-FREE HCC, IMPLYING CORRESPONDING DEFECTS OF EPIGENETIC REGULATION AND END RESECTION. CONCLUSION: THE ANTIRESECTION ACTIVITY OF HBX INDUCES AN HR DEFECT AND GENOMIC INSTABILITY AND CONTRIBUTES TO TUMORIGENESIS OF HOST HEPATOCYTES. 2019 3 1646 34 DOES THE HEPATITIS B ANTIGEN HBX PROMOTE THE APPEARANCE OF LIVER CANCER STEM CELLS? HEPATITIS B VIRUS (HBV) IS A MAJOR ETIOLOGIC AGENT OF CHRONIC LIVER DISEASE AND HEPATOCELLULAR CARCINOMA (HCC). HBV-ENCODED X ANTIGEN, HBX, AND PATHWAYS IMPLICATED IN THE SELF-RENEWAL OF STEM CELLS CONTRIBUTE TO HCC, BUT IT IS NOT CLEAR WHETHER HBX EXPRESSION PROMOTES "STEMNESS." THUS, EXPERIMENTS WERE DESIGNED TO TEST THE HYPOTHESIS THAT HBX TRIGGERS MALIGNANT TRANSFORMATION BY PROMOTING PROPERTIES THAT ARE CHARACTERISTIC OF CANCER STEM CELLS (CSC). TO TEST THIS HYPOTHESIS, HEPG2 CELLS WERE STABLY TRANSDUCED WITH HBX AND THEN ASSAYED FOR PHENOTYPIC AND MOLECULAR CHARACTERISTICS OF "STEMNESS." THE RELATIONSHIP BETWEEN HBX AND "STEMNESS"-ASSOCIATED MARKERS WAS ALSO EVALUATED BY IMMUNOHISTOCHEMICAL STAINING OF LIVER AND TUMOR TISSUE SECTIONS FROM HBV-INFECTED PATIENTS. THE RESULTS SHOWED THAT OCT-4, NANOG, KLF-4, BETA-CATENIN, AND EPITHELIAL CELL ADHESION MOLECULE (EPCAM) WERE ACTIVATED BY HBX IN VITRO AND IN VIVO. EPCAM WAS DETECTED IN THE NUCLEI OF HUMAN HCC CELLS FROM INFECTED PATIENTS. HBX PROMOTES "STEMNESS" BY ACTIVATING BETA-CATENIN AND EPIGENETIC UPREGULATION OF MIR-181, BOTH OF WHICH TARGET EPCAM. HBX EXPRESSION WAS ALSO ASSOCIATED WITH DEPRESSED LEVELS OF E-CADHERIN. MOREOVER, HBX STIMULATED CELL MIGRATION, GROWTH IN SOFT AGAR, AND SPHEROID FORMATION. THIS WORK IS THE FIRST TO PROPOSE THAT HBV PROMOTES "STEMNESS" IN THE PATHOGENESIS OF HCC. HBX-ASSOCIATED UPREGULATED EXPRESSION OF MULTIPLE "STEMNESS" MARKERS SUPPORTS THE HYPOTHESIS THAT HBX CONTRIBUTES TO HEPATOCARCINOGENESIS, AT LEAST IN PART, BY PROMOTING CHANGES IN GENE EXPRESSION THAT ARE CHARACTERISTICS OF CSCS. 2011 4 3246 23 HEPATITIS B VIRUS (HBV) INDUCES THE EXPRESSION OF INTERLEUKIN-8 THAT IN TURN REDUCES HBV SENSITIVITY TO INTERFERON-ALPHA. HIGH LEVELS OF SERUM INTERLEUKIN-8 (IL-8) HAVE BEEN DETECTED IN CHRONIC HEPATITIS B (CHB) PATIENTS DURING EPISODES OF HEPATITIS FLARES. WE INVESTIGATED WHETHER HEPATITIS B VIRUS (HBV) MAY DIRECTLY INDUCE IL-8 PRODUCTION AND WHETHER IL-8 MAY ANTAGONIZE INTERFERON-ALPHA (IFN-ALPHA) ANTIVIRAL ACTIVITY AGAINST HBV. WE SHOWED THAT CHB PATIENTS HAD SIGNIFICANTLY HIGHER IL-8 LEVELS BOTH IN SERUM AND IN LIVER TISSUE THAN CONTROLS. IN HBV-REPLICATING HEPG2 CELLS, IL-8 TRANSCRIPTION WAS SIGNIFICANTLY ACTIVATED. AP-1, C/EBP AND NF-KB TRANSCRIPTION FACTORS WERE CONCURRENTLY NECESSARY FOR MAXIMUM IL-8 INDUCTION. MOREOVER, HBX VIRAL PROTEIN WAS RECRUITED ONTO THE IL-8 PROMOTER AND THIS WAS PARALLELED BY IL8-BOUND HISTONE HYPERACETYLATION AND BY ACTIVE RECRUITMENT OF TRANSCRIPTIONAL COACTIVATORS. INHIBITION OF IL-8 INCREASES THE ANTIVIRAL ACTIVITY OF IFN-ALPHA AGAINST HBV. OUR RESULTS INDICATE THAT HBV ACTIVATES IL-8 GENE EXPRESSION BY TARGETING THE EPIGENETIC REGULATION OF THE IL-8 PROMOTER AND THAT IL-8 MAY CONTRIBUTE TO REDUCE HBV SENSITIVITY TO IFN-ALPHA. 2013 5 3189 23 HBX RELIEVES CHROMATIN-MEDIATED TRANSCRIPTIONAL REPRESSION OF HEPATITIS B VIRAL CCCDNA INVOLVING SETDB1 HISTONE METHYLTRANSFERASE. BACKGROUND & AIMS: MAINTENANCE OF THE COVALENTLY CLOSED CIRCULAR HBV DNA (CCCDNA) THAT SERVES AS A TEMPLATE FOR HBV TRANSCRIPTION IS RESPONSIBLE FOR THE FAILURE OF ANTIVIRAL THERAPIES. WHILE STUDIES IN CHRONIC HEPATITIS PATIENTS HAVE SHOWN THAT HIGH VIREMIA CORRELATES WITH HYPERACETYLATION OF CCCDNA-ASSOCIATED HISTONES, THE MOLECULAR MECHANISMS CONTROLLING CCCDNA STABILITY AND TRANSCRIPTIONAL REGULATION ARE STILL POORLY UNDERSTOOD. THIS STUDY AIMED TO DECIPHER THE ROLE OF CHROMATIN AND CHROMATIN MODIFIER PROTEINS ON HBV TRANSCRIPTION. METHODS: WE ANALYZED THE CHROMATIN STRUCTURE OF ACTIVELY TRANSCRIBED OR SILENCED CCCDNA BY INFECTING PRIMARY HUMAN HEPATOCYTES AND DIFFERENTIATED HEPARG CELLS WITH WILD-TYPE VIRUS OR VIRUS DEFICIENT (HBVX-) FOR THE EXPRESSION OF HEPATITIS B VIRUS X PROTEIN (HBX), THAT IS REQUIRED FOR HBV EXPRESSION. RESULTS: IN THE ABSENCE OF HBX, HBV CCCDNA WAS TRANSCRIPTIONALLY SILENCED WITH THE CONCOMITANT DECREASE OF HISTONE 3 (H3) ACETYLATION AND H3K4ME3, INCREASE OF H3 DI- AND TRI-METHYLATION (H3K9ME) AND THE RECRUITMENT OF HETEROCHROMATIN PROTEIN 1 FACTORS (HP1) THAT CORRELATE WITH CONDENSED CHROMATIN. SETDB1 WAS FOUND TO BE THE MAIN HISTONE METHYLTRANSFERASE RESPONSIBLE FOR THE DEPOSITION OF H3K9ME3 AND HBV REPRESSION. FINALLY, FULL TRANSCRIPTIONAL REACTIVATION OF HBVX- UPON HBX RE-EXPRESSION CORRELATED WITH AN INCREASE OF HISTONE ACETYLATION AND H3K4ME3, AND A CONCOMITANT DECREASE OF HP1 BINDING AND OF H3K9ME3 ON THE CCCDNA. CONCLUSION: UPON HBV INFECTION, CELLULAR MECHANISMS INVOLVING SETDB1-MEDIATED H3K9ME3 AND HP1 INDUCE SILENCING OF HBV CCCDNA TRANSCRIPTION THROUGH MODULATION OF CHROMATIN STRUCTURE. HBX IS ABLE TO RELIEVE THIS REPRESSION AND ALLOW THE ESTABLISHMENT OF ACTIVE CHROMATIN. 2015 6 5715 30 SIRT3 RESTRICTS HEPATITIS B VIRUS TRANSCRIPTION AND REPLICATION THROUGH EPIGENETIC REGULATION OF COVALENTLY CLOSED CIRCULAR DNA INVOLVING SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG 1 AND SET DOMAIN CONTAINING 1A HISTONE METHYLTRANSFERASES. HEPATITIS B VIRUS (HBV) INFECTION REMAINS A MAJOR HEALTH PROBLEM WORLDWIDE. MAINTENANCE OF THE COVALENTLY CLOSED CIRCULAR DNA (CCCDNA), WHICH SERVES AS A TEMPLATE FOR HBV RNA TRANSCRIPTION, IS RESPONSIBLE FOR THE FAILURE OF ERADICATING CHRONIC HBV DURING CURRENT ANTIVIRAL THERAPY. CCCDNA IS ASSEMBLED WITH CELLULAR HISTONE PROTEINS INTO CHROMATIN, BUT LITTLE IS KNOWN ABOUT THE REGULATION OF HBV CHROMATIN BY HISTONE POSTTRANSLATIONAL MODIFICATIONS. IN THIS STUDY, WE IDENTIFIED SILENT MATING TYPE INFORMATION REGULATION 2 HOMOLOG 3 (SIRT3) AS A HOST FACTOR RESTRICTING HBV TRANSCRIPTION AND REPLICATION BY SCREENING SEVEN MEMBERS OF THE SIRTUIN FAMILY, WHICH IS THE CLASS III HISTONE DEACETYLASE. ECTOPIC SIRT3 EXPRESSION SIGNIFICANTLY REDUCED TOTAL HBV RNAS, 3.5-KB RNA, AS WELL AS REPLICATIVE INTERMEDIATE DNA IN HBV-INFECTED HEPG2-NA(+) /TAUROCHOLATE COTRANSPORTING POLYPEPTIDE CELLS AND PRIMARY HUMAN HEPATOCYTES. IN CONTRAST, GENE SILENCING OF SIRT3 PROMOTED HBV TRANSCRIPTION AND REPLICATION. A MECHANISTIC STUDY FOUND THAT NUCLEAR SIRT3 WAS RECRUITED TO THE HBV CCCDNA, WHERE IT DEACETYLATED HISTONE 3 LYSINE 9. IMPORTANTLY, OCCUPANCY OF SIRT3 ON CCCDNA COULD INCREASE THE RECRUITMENT OF HISTONE METHYLTRANSFERASE SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG 1 TO CCCDNA AND DECREASE RECRUITMENT OF SET DOMAIN CONTAINING 1A, LEADING TO A MARKED INCREASE OF TRIMETHYL-HISTONE H3 (LYS9) AND A DECREASE OF TRIMETHYL-HISTONE H3 (LYS4) ON CCCDNA. MOREOVER, SIRT3-MEDIATED HBV CCCDNA TRANSCRIPTIONAL REPRESSION INVOLVED DECREASED BINDING OF HOST RNA POLYMERASE II AND TRANSCRIPTION FACTOR YIN YANG 1 TO CCCDNA. FINALLY, HEPATITIS B VIRAL X PROTEIN COULD RELIEVE SIRT3-MEDIATED CCCDNA TRANSCRIPTIONAL REPRESSION BY INHIBITING BOTH SIRT3 EXPRESSION AND ITS RECRUITMENT TO CCCDNA. CONCLUSION: SIRT3 IS A HOST FACTOR EPIGENETICALLY RESTRICTING HBV CCCDNA TRANSCRIPTION BY ACTING COOPERATIVELY WITH HISTONE METHYLTRANSFERASE; THESE DATA PROVIDE A RATIONALE FOR THE USE OF SIRT3 ACTIVATORS IN THE PREVENTION OR TREATMENT OF HBV INFECTION. (HEPATOLOGY 2018). 2018 7 1700 38 DYNAMIC EXPRESSION OF ZNF382 AND ITS TUMOR-SUPPRESSOR ROLE IN HEPATITIS B VIRUS-RELATED HEPATOCELLULAR CARCINOGENESIS. HEPATITIS B VIRUS (HBV) INFECTION IS THE PRIMARY CAUSE OF HEPATOCELLULAR CARCINOMA (HCC). ZINC-FINGER PROTEIN 382 (ZNF382), WHICH BELONGS TO ZINC-FINGER PROTEIN FAMILY, HAS BEEN DOCUMENTED TO BE DOWNREGULATED IN CERTAIN TYPES OF CANCER. HOWEVER, ITS ROLE IN HCC REMAINS LARGELY UNKNOWN. IN THIS STUDY, WE DEMONSTRATED THAT ZNF382 EXPRESSION WAS SIGNIFICANTLY ELEVATED IN HBV-INFECTED LIVER CIRRHOSIS TISSUES RELATIVE TO HBV-NEGATIVE NORMAL LIVER TISSUES AT PROTEIN LEVELS, BUT NOT AT MRNA LEVELS, AND WAS POSITIVELY CORRELATED WITH THE LEVELS OF HBV DNA AND HEPATITIS B VIRUS X PROTEIN (HBX). FURTHER STUDIES REVEALED THAT ZNF382 WAS A TARGET OF MIR-6867, AND HBX PROMOTED THE TRANSLATION OF ZNF382 DURING HBV CHRONIC INFECTION THROUGH ERK-MEDIATED MIR-6867 INHIBITION. IN ADDITION, OUR DATA SHOWED THAT ZNF382 WAS FREQUENTLY DOWNREGULATED BY PROMOTER METHYLATION IN HBV-RELATED HCCS RELATIVE TO HBV-INFECTED LIVER CIRRHOSIS TISSUES, AND DECREASED EXPRESSION OF ZNF382 WAS STRONGLY CORRELATED WITH POOR SURVIVAL IN EARLY-STAGE HCC PATIENTS. FUNCTIONAL STUDIES DEMONSTRATED THAT ZNF382 WAS A POTENT TUMOR SUPPRESSOR IN HCC CELLS THROUGH INHIBITING CELL PROLIFERATION, COLONY FORMATION, MIGRATION, INVASION, AND TUMORIGENIC POTENTIAL IN NUDE MICE, AND INDUCING CELL APOPTOSIS. MECHANISTICALLY, ZNF382 EXERTED ITS TUMOR-SUPPRESSOR FUNCTIONS IN HCC THROUGH TRANSCRIPTIONALLY REPRESSING ITS DOWNSTREAM TARGETS SUCH AS FOS PROTO-ONCOGENE (FOS), JUN PROTO-ONCOGENE (JUN), DISHEVELED SEGMENT POLARITY PROTEIN 2 (DVL2), AND FRIZZLED CLASS RECEPTOR 1 (FZD1), THEREBY IMPAIRING THE ACTIVITIES OF ACTIVATING PROTEIN 1 (AP-1) AND WNT/BETA-CATENIN PATHWAYS AND ACTIVATING P53 SIGNALING. ALTOGETHER, OUR DATA SHOW THAT ZNF382 ACTS AS A TUMOR SUPPRESSOR, AND IS CO-REGULATED BY HBX AND EPIGENETIC MECHANISM IN HBV-RELATED HEPATOCELLULAR CARCINOGENESIS. 2019 8 3794 35 INTERLEUKIN-33 MEDIATES BOTH IMMUNE-RELATED AND NON-IMMUNE-RELATED INHIBITORY EFFECTS AGAINST HEPATITIS B VIRUS. CHRONIC INFECTION BY HEPATITIS B VIRUS (HBV) IS ASSOCIATED WITH HIGH RISKS OF LIVER FIBROSIS, CIRRHOSIS AND HEPATOCELLULAR CARCINOMA. HBV COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IN THE NUCLEUS OF INFECTED HEPATOCYTE SERVES AS TRANSCRIPTION TEMPLATE. NEITHER NATURAL RESOLUTION OF ACUTE INFECTION NOR CURRENT TREATMENT OPTIONS FOR CHRONIC INFECTION ARE BELIEVED TO CAUSE CCCDNA CLEARANCE. WE PREVIOUSLY SHOWED THAT INJECTION OF IL-33-EXPRESSING PLASMID FACILITATED CLEARANCE OF INTRAHEPATIC HBV DNA IN A MOUSE MODEL OF HBV PERSISTENCE. IN THIS WORK, HBV-TARGETING THERAPEUTIC EFFECTS OF IL-33 WERE FURTHER EXPLORED. MURINE IL-33 DELIVERED BY RECOMBINANT ADENO-ASSOCIATED VIRUS (AAV-MIL-33) INDUCED CLEARANCE OF BOTH SERUM HBV MARKERS AND INTRAHEPATIC HBV DNA IN TWO MOUSE MODELS OF HBV PERSISTENCE BASED ON REPLICON PLASMID AND RECOMBINANT CCCDNA (RCCCDNA) RESPECTIVELY. CLEARANCE WAS ASSOCIATED WITH SERUM ALT ELEVATIONS AND LIVER INFILTRATIONS BY CD4(+) AND CD8(+) T CELLS, INDICATING IL-33-INDUCED CELLULAR IMMUNE RESPONSES AGAINST HBV-HARBORING CELLS. ADOPTIVE TRANSFER OF SPLENOCYTES FROM AAV-MIL-33-CURED MICE WAS INDEED SUFFICIENT TO ENGENDER SIMILAR CLEARANCE IN RECIPIENT MICE. IN VITRO, INTRACELLULAR, INSTEAD OF EXTRACELLULAR, IL-33 WAS MAINLY RESPONSIBLE FOR REPRESSING VIRAL TRANSCRIPTION, PROTEIN PRODUCTION AND GENOME REPLICATION IN HUH7 CELLS TRANSFECTED WITH HBV REPLICON OR RCCCDNA. IL-33 WAS SHOWN TO BE RECRUITED ONTO RCCCDNA MINICHROMOSOME ACCOMPANIED BY LOSS OF TRANSCRIPTIONAL ACTIVATION EPIGENETIC MARKS. FINALLY, TRANSFECTION OF IL-33 INTO HBV-INFECTED HEPG2/NTCP CELLS RESULTED IN REDUCED TRANSCRIPTION, ANTIGEN EXPRESSION AND GENOME REPLICATION, SUGGESTING REPRESSION OF CANONICAL CCCDNA. THESE DATA DEMONSTRATED DIVERSE INHIBITORY EFFECTS ON HBV AND HBV-INFECTED CELLS MEDIATED BY IL-33, AND SUGGEST IL-33 AS AN INTERESTING THERAPEUTIC CANDIDATE. 2022 9 6753 20 WILD TYPE HBX AND TRUNCATED HBX: PLEIOTROPIC REGULATORS DRIVING SEQUENTIAL GENETIC AND EPIGENETIC STEPS OF HEPATOCARCINOGENESIS AND PROGRESSION OF HBV-ASSOCIATED NEOPLASMS. HEPATITIS B VIRUS (HBV) IS ONE OF THE CAUSATIVE AGENTS OF HEPATOCELLULAR CARCINOMA. THE MOLECULAR MECHANISMS OF TUMORIGENESIS ARE COMPLEX. ONE OF THE HOST FACTORS INVOLVED IS APPARENTLY THE LONG-LASTING INFLAMMATORY REACTION WHICH ACCOMPANIES CHRONIC HBV INFECTION. ALTHOUGH HBV LACKS A TYPICAL VIRAL ONCOGENE, THE HBX GENE ENCODING A PLEIOTROPIC REGULATORY PROTEIN EMERGED AS A MAJOR PLAYER IN LIVER CARCINOGENESIS. HERE WE REVIEW THE TUMORIGENIC FUNCTIONS OF HBX WITH AN EMPHASIS ON WILD TYPE AND TRUNCATED HBX VARIANTS, AND THEIR ROLE IN THE TRANSCRIPTIONAL DYSREGULATION AND EPIGENETIC REPROGRAMMING OF THE HOST CELL GENOME. WE SUGGEST THAT HBX ACQUIRED BY THE HBV GENOME DURING EVOLUTION ACTS LIKE A CELLULAR PROTO-ONC GENE THAT IS ACTIVATED BY DELETION DURING HEPATOCARCINOGENESIS. THE RESULTING VIRAL ONCOGENE (V-ONC GENE) CODES FOR A TRUNCATED HBX PROTEIN THAT FACILITATES TUMOR PROGRESSION. COPYRIGHT (C) 2015 JOHN WILEY & SONS, LTD. 2016 10 4239 28 METHYLATION PROFILE OF HEPATITIS B VIRUS IS NOT INFLUENCED BY INTERFERON ALPHA IN HUMAN LIVER CANCER CELLS. INTERFERON (IFN) ALPHA IS USED FOR THE TREATMENT OF CHRONIC HEPATITIS B VIRUS (HBV) INFECTION, BUT THE MOLECULAR MECHANISMS UNDERLYING ITS ANTIVIRAL EFFECT HAVE NOT BEEN FULLY ELUCIDATED. EPIGENETIC MODIFICATIONS REGULATE THE TRANSCRIPTIONAL ACTIVITY OF COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IN CELLS WITH CHRONIC HBV INFECTION. IFN?ALPHA HAS BEEN SHOWN TO MODIFY CCCDNA?BOUND HISTONES, BUT IT IS NOT KNOWN WHETHER THE ANTI?HBV EFFECT OF IFN?ALPHA INVOLVES METHYLATION OF CCCDNA. THE PRESENT STUDY AIMED TO DETERMINE WHETHER IFN?ALPHA INDUCED METHYLATION OF HBV CCCDNA IN A CELL?BASED MODEL IN WHICH HEPG2 CELLS WERE DIRECTLY INFECTED WITH WILD?TYPE HBV VIRIONS. METHYLATION STATUS OF HBV CCCDNA WAS ASSESSED USING GLOBAL DNA METHYLATION ELISA ASSAY, METHYLATION?SPECIFIC PCR AND BISULFITE SEQUENCING. IFN?ALPHA SUPPRESSED HBV DNA AND RNA TRANSCRIPTS, BUT METHYLATION PROFILES WERE SIMILAR BETWEEN THE CONTROL AND IFN?ALPHA TREATED GROUPS. CHROMATIN IMMUNOPRECIPITATION RESULTS REVEALED BINDING OF DNA METHYLTRANSFERASES (DNMT) 3A AND DNMT3B TO HBV CCCDNA AND TREATMENT WITH IFN?ALPHA SUPPRESSED THE RECRUITMENT OF DNMT3B TO CCCDNA. TAKEN TOGETHER, THESE RESULTS SUGGEST THAT IFN?ALPHA DOES NOT INDUCE METHYLATION OF HBV CCCDNA. THEREFORE, IT WAS CONCLUDED THAT METHYLATION IS UNLIKELY TO CONTRIBUTE TO THE ANTI?HBV EFFECT OF IFN?ALPHA IN HEPG2 CELLS, AND THAT ALTERNATIVE MECHANISMS NEED TO BE SOUGHT TO ENHANCE CCCDNA METHYLATION AS A NOVEL THERAPY AGAINST HBV. 2021 11 3619 35 IN VIVO ACUTE ON CHRONIC ETHANOL EFFECTS IN LIVER: A MOUSE MODEL EXHIBITING EXACERBATED INJURY, ALTERED METABOLIC AND EPIGENETIC RESPONSES. CHRONIC ALCOHOLICS WHO ALSO BINGE DRINK (I.E., ACUTE ON CHRONIC) ARE PRONE TO AN EXACERBATED LIVER INJURY BUT ITS MECHANISM IS NOT UNDERSTOOD. WE THEREFORE INVESTIGATED THE IN VIVO EFFECTS OF CHRONIC AND BINGE ETHANOL INGESTION AND COMPARED TO CHRONIC ETHANOL FOLLOWED BY THREE REPEAT BINGE ETHANOL ON THE LIVER OF MALE C57/BL6 MICE FED ETHANOL IN LIQUID DIET (4%) FOR FOUR WEEKS FOLLOWED BY BINGE ETHANOL (INTRAGASTRIC ADMINISTRATION, 3.5 G/KG BODY WEIGHT, THREE DOSES, 12H APART). CHRONIC FOLLOWED BY BINGE ETHANOL EXACERBATED FAT ACCUMULATION, NECROSIS, DECREASE IN HEPATIC SAM AND SAM:SAH RATIO, INCREASE IN ADENOSINE LEVELS, AND ELEVATED CYP2E1 LEVELS. HISTONE H3 LYSINE ACETYLATION (H3ACK9), DUALLY MODIFIED PHOSPHOACETYLATED HISTONE H3 (H3ACK9/PS10), AND PHOSPHORYLATED H2AX INCREASED AFTER BINGE WHEREAS PHOSPHORYLATION OF HISTONE H3 SER 10 (H3S10) AND H3 SER 28 (H3S28) INCREASED AFTER CHRONIC ETHANOL-BINGE. HISTONE H3 LYSINE 4 AND 9 DIMETHYLATION INCREASED WITH A MARKED DIMETHYLATION IN H3K9 IN CHRONIC ETHANOL BINGE GROUP. TRIMETHYLATED HISTONE H3 LEVELS DID NOT CHANGE. NUCLEAR LEVELS OF HISTONE ACETYL TRANSFERASE GCN5 AND HISTONE DEACETYLASE HDAC3 WERE ELEVATED WHEREAS PHOSPHO-CREB DECREASED IN A DISTINCTIVE MANNER. TAKEN TOGETHER, ACUTE ON CHRONIC ETHANOL INGESTION CAUSED AMPLIFICATION OF LIVER INJURY AND ELICITED CHARACTERISTIC PROFILES OF HISTONE MODIFICATIONS, METABOLIC ALTERATIONS, AND CHANGES IN NUCLEAR PROTEIN LEVELS. THESE FINDINGS DEMONSTRATE THAT CHRONIC ETHANOL EXPOSURE RENDERS LIVER MORE SUSCEPTIBLE TO REPEAT ACUTE/BINGE ETHANOL INDUCED ACCELERATION OF ALCOHOLIC LIVER DISEASE. 2015 12 10 34 14-3-3 LIGAND PREVENTS NUCLEAR IMPORT OF C-ABL PROTEIN IN CHRONIC MYELOID LEUKEMIA. HERE WE DEMONSTRATED THAT THE 'LOSS OF FUNCTION' OF NOT-REARRANGED C-ABL IN CHRONIC MYELOID LEUKEMIA (CML) IS PROMOTED BY ITS CYTOPLASMIC COMPARTMENTALIZATION BOUND TO 14-3-3 SIGMA SCAFFOLDING PROTEIN. IN PARTICULAR, CONSTITUTIVE TYROSINE KINASE (TK) ACTIVITY OF P210 BCR-ABL BLOCKS C-JUN N-TERMINAL KINASE (JNK) PHOSPHORYLATION LEADING TO 14-3-3 SIGMA PHOSPHORYLATION AT A CRITICAL RESIDUE (SER(186)) FOR C-ABL BINDING IN RESPONSE TO DNA DAMAGE. MOREOVER, IT IS ASSOCIATED WITH 14-3-3 SIGMA OVER-EXPRESSION ARISING FROM EPIGENETIC MECHANISMS (PROMOTER HYPER-ACETYLATION). ACCORDINGLY, P210 BCR-ABL TK INHIBITION BY THE TK INHIBITOR IMATINIB MESYLATE (IM) EVOKES MULTIPLE EVENTS, INCLUDING JNK PHOSPHORYLATION AT THR(183), P38 MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) PHOSPHORYLATION AT THR(180), C-ABL DE-PHOSPHORYLATION AT SER RESIDUES INVOLVED IN 14-3-3 BINDING AND REDUCTION OF 14-3-3 SIGMA EXPRESSION, THAT LET C-ABL RELEASE FROM 14-3-3 SIGMA AND NUCLEAR IMPORT, AND ADDRESS BCR-ABL-EXPRESSING CELLS TOWARDS APOPTOTIC DEATH. INFORMATIONAL SPECTRUM METHOD (ISM), A VIRTUAL SPECTROSCOPY METHOD FOR ANALYSIS OF PROTEIN INTERACTIONS BASED ON THEIR STRUCTURE, AND MATHEMATICAL FILTERING IN CROSS SPECTRUM (CS) ANALYSIS IDENTIFIED 14-3-3 SIGMA/C-ABL BINDING SITES. FURTHER INVESTIGATION ON CS PROFILES OF C-ABL- AND P210 BCR-ABL-CONTAINING COMPLEXES REVEALED THE MECHANISM LIKELY INVOLVED 14-3-3 PRECLUDED PHOSPHORYLATION IN CML CELLS. 2009 13 1826 37 EFFECTS OF HISTONE DEACETYLASE INHIBITOR ON EXTRACELLULAR MATRIX PRODUCTION IN HUMAN NASAL POLYP ORGAN CULTURES. BACKGROUND: NASAL POLYPOSIS IS ASSOCIATED WITH A CHRONIC INFLAMMATORY CONDITION OF THE SINONASAL MUCOSA AND INVOLVES MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION. EPIGENETIC MODULATION BY HISTONE DEACETYLASE (HDAC) INHIBITORS INCLUDING TRICHOSTATIN A (TSA) HAS BEEN REPORTED TO HAVE INHIBITORY EFFECTS ON MYOFIBROBLAST DIFFERENTIATION IN LUNG AND RENAL FIBROBLASTS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE THE INHIBITORY EFFECT OF TSA ON MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION IN NASAL POLYP ORGAN CULTURES. METHODS: NASAL POLYP TISSUES FROM 18 PATIENTS WERE ACQUIRED DURING ENDOSCOPIC SINUS SURGERY. AFTER ORGAN CULTURE, NASAL POLYPS WERE STIMULATED WITH TGF-BETA1 AND THEN TREATED WITH TSA. ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), FIBRONECTIN, AND COLLAGEN TYPE I EXPRESSION LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION (PCR), REAL-TIME PCR, WESTERN BLOT, AND IMMUNOFLUORESCENT STAINING. HDAC2, HDAC4, AND ACETYLATED H4 EXPRESSION LEVELS WERE ASSAYED BY WESTERN BLOT. CYTOTOXICITY WAS ANALYZED BY THE TERMINAL DEOXYNUCLEOTIDYL TRANSFERASE BIOTIN-DUTP NICK END LABELING ASSAY. RESULTS: THE EXPRESSION LEVELS OF ALPHA-SMA, FIBRONECTIN, AND COLLAGEN TYPE 1 WERE INCREASED IN NASAL POLYP AFTER TRANSFORMING GROWTH FACTOR (TGF) BETA1 TREATMENT. TSA-INHIBITED TGF-BETA1 INDUCED THESE GENE AND PROTEIN EXPRESSION LEVELS. FURTHERMORE, TSA SUPPRESSED PROTEIN EXPRESSION LEVELS OF HDAC2 AND HDAC4. HOWEVER, TSA INDUCED HYPERACETYLATION OF HISTONES H4. TREATMENT WITH TGF-BETA1 WITH OR WITHOUT TSA DID NOT HAVE CYTOTOXIC EFFECT. CONCLUSION: THESE FINDINGS PROVIDE NOVEL INSIGHTS INTO THE EPIGENETIC REGULATION IN MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION OF NASAL POLYP. TSA COULD BE A CANDIDATE OF A THERAPEUTIC AGENT FOR REVERSING THE TGF-BETA1-INDUCED ECM SYNTHESIS THAT LEADS TO NASAL POLYP DEVELOPMENT. 2013 14 3175 36 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 15 3185 25 HBC BINDS TO THE CPG ISLANDS OF HBV CCCDNA AND PROMOTES AN EPIGENETIC PERMISSIVE STATE. HBV COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IS THE TEMPLATE FOR THE TRANSCRIPTION OF HBV. HBV CORE PROTEIN (HBC) IS A MAIN COMPONENT OF THE HBV CCCDNA MINICHROMOSOME. HOWEVER, THE FUNCTION OF HBC IN CCCDNA IS NOT FULLY UNDERSTOOD. IN LIGHT OF RECENT FINDINGS THAT HBV CCCDNA MAY BE REGULATED EPIGENETICALLY, WE ANALYZED THE BINDING OF HBC TO CCCDNA AND THE IMPACT OF HBC ON CCCDNA EPIGENETIC PROFILE IN THE LIVER BIOPSY SAMPLES OF 22 PATIENTS WITH CHRONIC HEPATITIS B (CHB). WE FOUND THAT HBC BINDING TO HBV CCCDNA OCCURRED PREFERENTIALLY AT CPG ISLAND 2, AN IMPORTANT REGION FOR THE REGULATION OF HBV TRANSCRIPTION. FURTHERMORE, THE RELATIVE ABUNDANCES OF HBC BINDING TO CPG ISLAND 2 WERE POSITIVELY CORRELATED WITH THE RATIOS OF RELAXED CIRCULAR DNA TO CCCDNA AND THE LEVELS OF SERUM HBV DNA IN THOSE PATIENTS. INTERESTINGLY, THE RELATIVE ABUNDANCES OF HBC BINDING TO CPG ISLAND 2 WERE ASSOCIATED WITH THE BINDING OF CREB BINDING PROTEIN (CBP) AND WITH HYPOMETHYLATION IN CPG ISLAND 2 OF HBV CCCDNA MINICHROMOSOMES. HOWEVER, RELATIVELY HIGHER AMOUNTS OF HBC BINDING TO CPG ISLAND 2 OF CCCDNA WERE ACCOMPANIED BY LOWER AMOUNTS OF HDAC1 BINDING. MULTIVARIATE ANALYSIS REVEALED THAT THE ABUNDANCES OF HBC BINDING TO CPG ISLAND 2 OF CCCDNA AND POSITIVE HBEAG WERE INDEPENDENT FACTORS ASSOCIATED WITH THE REPLICATION OF HBV (P = 0.001 FOR BOTH). APPARENTLY, HBC IS A POSITIVE REGULATOR OF HBV TRANSCRIPTION AND REPLICATION, MAINTAINING THE PERMISSIVE EPIGENETIC STATE IN THE CRITICAL REGION OF THE HBV CCCDNA MINICHROMOSOMES. 2011 16 2433 29 EPIGENETIC SILENCING OF NAD(P)H:QUINONE OXIDOREDUCTASE 1 BY HEPATITIS B VIRUS X PROTEIN INCREASES MITOCHONDRIAL INJURY AND CELLULAR SUSCEPTIBILITY TO OXIDATIVE STRESS IN HEPATOMA CELLS. NAD(P)H:QUINONE OXIDOREDUCTASE 1 (NQO1) IS A PHASE II ENZYME THAT PARTICIPATES IN THE DETOXIFICATION OF DOPAMINE-DERIVED QUINONE MOLECULES AND REACTIVE OXYGEN SPECIES. OUR PRIOR WORK USING A PROTEOMIC APPROACH FOUND THAT NQO1 PROTEIN LEVELS WERE SIGNIFICANTLY DECREASED IN STABLE HEPATITIS B VIRUS (HBV)-PRODUCING HEPATOMA CELLS RELATIVE TO THE EMPTY-VECTOR-TRANSFECTED CONTROLS. HOWEVER, THE MECHANISM AND BIOLOGICAL SIGNIFICANCE OF THE NQO1 SUPPRESSION REMAIN ELUSIVE. IN THIS STUDY WE DEMONSTRATE THAT HBV X PROTEIN (HBX) INDUCES EPIGENETIC SILENCING OF NQO1 IN HEPATOMA CELLS THROUGH PROMOTER HYPERMETHYLATION VIA RECRUITMENT OF DNA METHYLTRANSFERASE DNMT3A TO THE PROMOTER REGION OF THE NQO1 GENE. IN HBV-RELATED HEPATOCELLULAR CARCINOMA (HCC) SPECIMENS, HBX EXPRESSION WAS CORRELATED NEGATIVELY TO NQO1 TRANSCRIPTS BUT POSITIVELY TO NQO1 PROMOTER HYPERMETHYLATION. DOWNREGULATION OF NQO1 BY HBX REDUCED INTRACELLULAR GLUTATHIONE LEVELS, IMPAIRED MITOCHONDRIAL FUNCTION, AND INCREASED SUSCEPTIBILITY OF HEPATOMA CELLS TO OXIDATIVE STRESS-INDUCED CELL INJURY. THESE RESULTS SUGGEST A NOVEL MECHANISM FOR HBV-MEDIATED PATHOGENESIS OF CHRONIC LIVER DISEASES, INCLUDING HCC. 2013 17 3186 29 HBV COVALENTLY CLOSED CIRCULAR DNA MINICHROMOSOMES IN DISTINCT EPIGENETIC TRANSCRIPTIONAL STATES DIFFER IN THEIR VULNERABILITY TO DAMAGE. BACKGROUND AND AIMS: HBV COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IS A MAJOR OBSTACLE FOR A CURE OF CHRONIC HEPATITIS B. ACCUMULATING EVIDENCE SUGGESTS THAT EPIGENETIC MODIFICATIONS REGULATE THE TRANSCRIPTIONAL ACTIVITY OF CCCDNA MINICHROMOSOMES. HOWEVER, IT REMAINS UNCLEAR HOW THE EPIGENETIC STATE OF CCCDNA AFFECTS ITS STABILITY. APPROACHES AND RESULTS: BY USING HBV INFECTION CELL MODELS AND IN VITRO AND IN VIVO RECOMBINANT CCCDNA (RCCCDNA) AND HBVCIRCLE MODELS, THE REDUCTION RATE OF HBV CCCDNA AND THE EFFICACY OF APOLIPOPROTEIN B MRNA EDITING ENZYME CATALYTIC SUBUNIT 3A (APOBEC3A)-MEDIATED AND CRISPR/CRISPR-ASSOCIATED 9 (CAS9)-MEDIATED CCCDNA TARGETING WERE COMPARED BETWEEN CCCDNAS WITH DISTINCT TRANSCRIPTIONAL ACTIVITIES. INTERFERON-ALPHA TREATMENT AND HEPATITIS B X PROTEIN (HBX) DELETION WERE APPLIED AS TWO STRATEGIES FOR CCCDNA REPRESSION. CHROMATIN IMMUNOPRECIPITATION AND MICROCOCCAL NUCLEASE ASSAYS WERE PERFORMED TO DETERMINE THE EPIGENETIC PATTERN OF CCCDNA. HBV CCCDNA LEVELS REMAINED STABLE IN NONDIVIDING HEPATOCYTES; HOWEVER, THEY WERE SIGNIFICANTLY REDUCED DURING CELL DIVISION, AND THE REDUCTION RATE WAS SIMILAR BETWEEN CCCDNAS IN TRANSCRIPTIONALLY ACTIVE AND TRANSCRIPTIONALLY REPRESSED STATES. STRIKINGLY, HBV RCCCDNA WITHOUT HBX EXPRESSION EXHIBITED A SIGNIFICANTLY LONGER PERSISTENCE IN MICE. THE CCCDNA WITH LOW TRANSCRIPTIONAL ACTIVITY EXHIBITED AN EPIGENETICALLY INACTIVE PATTERN AND WAS MORE DIFFICULT TO ACCESS BY APOBEC3A AND ENGINEERED CRISPR-CAS9. THE EPIGENETIC REGULATOR ACTIVATING CCCDNA INCREASED ITS VULNERABILITY TO APOBEC3A. CONCLUSIONS: HBV CCCDNA MINICHROMOSOMES IN DISTINCT EPIGENETIC TRANSCRIPTIONAL STATES SHOWED A SIMILAR REDUCTION RATE DURING CELL DIVISION BUT SIGNIFICANTLY DIFFERED IN THEIR ACCESSIBILITY AND VULNERABILITY TO TARGETED NUCLEASES AND ANTIVIRAL AGENTS. EPIGENETIC SENSITIZATION OF CCCDNA MAKES IT MORE SUSCEPTIBLE TO DAMAGE AND MAY POTENTIALLY CONTRIBUTE TO AN HBV CURE. 2022 18 4546 31 MUTANT P53 REGULATES ENHANCER-ASSOCIATED H3K4 MONOMETHYLATION THROUGH INTERACTIONS WITH THE METHYLTRANSFERASE MLL4. MONOMETHYLATION OF HISTONE H3 LYSINE 4 (H3K4ME1) IS ENRICHED AT ENHANCERS THAT ARE PRIMED FOR ACTIVATION AND THE LEVELS OF THIS HISTONE MARK ARE FREQUENTLY ALTERED IN VARIOUS HUMAN CANCERS. YET, HOW ALTERATIONS IN H3K4ME1 ARE ESTABLISHED AND THE CONSEQUENCES OF THESE EPIGENETIC CHANGES IN TUMORIGENESIS ARE NOT WELL UNDERSTOOD. USING CHIP-SEQ IN HUMAN COLON CANCER CELLS, WE DEMONSTRATE THAT MUTANT P53 DEPLETION RESULTS IN DECREASED H3K4ME1 LEVELS AT ACTIVE ENHANCERS THAT REVEAL A STRIKING COLOCALIZATION OF MUTANT P53 AND THE H3K4 MONOMETHYLTRANSFERASE MLL4 FOLLOWING CHRONIC TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) SIGNALING. WE FURTHER REVEAL THAT MUTANT P53 FORMS PHYSIOLOGICAL ASSOCIATIONS AND DIRECT INTERACTIONS WITH MLL4 AND PROMOTES THE ENHANCER BINDING OF MLL4, WHICH IS REQUIRED FOR TNFALPHA-INDUCIBLE H3K4ME1 AND HISTONE H3 LYSINE 27 ACETYLATION (H3K27AC) LEVELS, ENHANCER-DERIVED TRANSCRIPT (ERNA) SYNTHESIS, AND MUTANT P53-DEPENDENT TARGET GENE ACTIVATION. COMPLEMENTARY IN VITRO STUDIES WITH RECOMBINANT CHROMATIN AND PURIFIED PROTEINS DEMONSTRATE THAT BINDING OF THE MLL3/4 COMPLEX AND H3K4ME1 DEPOSITION IS ENHANCED BY MUTANT P53 AND P300-MEDIATED ACETYLATION, WHICH IN TURN REFLECTS A MLL3/4-DEPENDENT ENHANCEMENT OF MUTANT P53 AND P300-DEPENDENT TRANSCRIPTIONAL ACTIVATION. COLLECTIVELY, OUR FINDINGS ESTABLISH A MECHANISM IN WHICH MUTANT P53 COOPERATES WITH MLL4 TO REGULATE ABERRANT ENHANCER ACTIVITY AND TUMOR-PROMOTING GENE EXPRESSION IN RESPONSE TO CHRONIC IMMUNE SIGNALING. 2018 19 3264 35 HEPATITIS VIRUS INFECTION AFFECTS DNA METHYLATION IN MICE WITH HUMANIZED LIVERS. BACKGROUND & AIMS: CELLS OF TUMORS ASSOCIATED WITH CHRONIC INFLAMMATION FREQUENTLY HAVE ALTERED PATTERNS OF DNA METHYLATION, INCLUDING HEPATOCELLULAR CARCINOMAS. CHRONIC HEPATITIS HAS ALSO BEEN ASSOCIATED WITH ABERRANT DNA METHYLATION, BUT LITTLE IS KNOWN ABOUT THEIR RELATIONSHIP. METHODS: PYROSEQUENCING WAS USED TO DETERMINE THE METHYLATION STATUS OF CULTURED HUH7.5.1 HEPATOMA CELLS AFTER HEPATITIS C VIRUS (HCV) INFECTION. WE ALSO STUDIED MICE WITH SEVERE COMBINED IMMUNODEFICIENCY CARRYING THE UROKINASE-TYPE PLASMINOGEN ACTIVATOR TRANSGENE CONTROLLED BY AN ALBUMIN PROMOTER (UROKINASE-TYPE PLASMINOGEN ACTIVATOR/SEVERE COMBINED IMMUNODEFICIENT MICE), IN WHICH UP TO 85% OF HEPATOCYTES WERE REPLACED BY HUMAN HEPATOCYTES (CHIMERIC MICE). MICE WERE GIVEN INTRAVENOUS INJECTIONS OF HEPATITIS B VIRUS (HBV) OR HCV, LIVER TISSUES WERE COLLECTED, AND DNA METHYLATION PROFILES WERE DETERMINED AT DIFFERENT TIME POINTS AFTER INFECTION. WE ALSO COMPARED METHYLATION PATTERNS BETWEEN PAIRED SAMPLES OF HEPATOCELLULAR CARCINOMAS AND ADJACENT NONTUMOR LIVER TISSUES FROM PATIENTS. RESULTS: NO REPRODUCIBLE CHANGES IN DNA METHYLATION WERE OBSERVED AFTER INFECTION OF HUH7.5.1 CELLS WITH HCV. LIVERS FROM HBV- AND HCV-INFECTED MICE HAD GENOME-WIDE, TIME-DEPENDENT CHANGES IN DNA METHYLATION, COMPARED WITH UNINFECTED UROKINASE-TYPE PLASMINOGEN ACTIVATOR/SEVERE COMBINED IMMUNODEFICIENT MICE. THERE WERE CHANGES IN 160 +/- 63 GENES IN HBV-INFECTED AND 237 +/- 110 GENES IN HCV-INFECTED MICE. METHYLATION OF 149 COMMON GENES INCREASED IN HBV- AND HCV-INFECTED MICE; METHYLATION OF SOME OF THESE GENES ALSO INCREASED IN HEPATOCELLULAR CARCINOMA SAMPLES FROM PATIENTS COMPARED WITH NONTUMOR TISSUES. EXPRESSION OF IFNG, WHICH IS EXPRESSED BY NATURAL KILLER CELLS, INCREASED SIGNIFICANTLY IN CHIMERIC LIVERS, IN CONCORDANCE WITH INDUCTION OF DNA METHYLATION, AFTER INFECTION WITH HBV OR HCV. INDUCTION OF IFNG WAS REDUCED AFTER ADMINISTRATION OF AN INHIBITOR OF NATURAL KILLER CELL FUNCTION (ANTI-ASIALO GM1). CONCLUSIONS: IN CHIMERIC MICE WITH HUMANIZED LIVERS, INFECTION WITH HBV AND HCV APPEARS TO ACTIVATE A NATURAL KILL CELL-DEPENDENT INNATE IMMUNE RESPONSE. THIS CONTRIBUTES TO THE INDUCTION AND ACCUMULATION OF ABERRANT DNA METHYLATION IN HUMAN HEPATOCYTES. 2014 20 3373 30 HISTONE MODULATION BLOCKS TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER OF VIRUS-SPECIFIC CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS-INFECTED CATS. CD8(+) T CELLS ARE CRITICAL FOR CONTROLLING HIV INFECTION. DURING THE CHRONIC PHASE OF LENTIVIRAL INFECTION, CD8(+) T CELLS LOSE THEIR PROLIFERATIVE CAPACITY AND EXHIBIT IMPAIRED ANTIVIRAL FUNCTION. THIS LOSS OF CD8(+) T CELL FUNCTION IS DUE, IN PART, TO CD4(+)CD25(+) T REGULATORY (TREG) CELL-MEDIATED SUPPRESSION. OUR RESEARCH GROUP HAS DEMONSTRATED THAT LENTIVIRUS-ACTIVATED CD4(+)CD25(+) TREG CELLS INDUCE THE REPRESSIVE TRANSCRIPTION FACTOR FORKHEAD BOX P3 (FOXP3) IN AUTOLOGOUS CD8(+) T CELLS FOLLOWING CO-CULTURE. WE HAVE RECENTLY REPORTED THAT TREG-INDUCED FOXP3 BINDS THE INTERLEUKIN-2 (IL-2), INTERFERON-GAMMA (IFN- GAMMA), AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PROMOTERS IN VIRUS-SPECIFIC CD8(+) T CELLS. THESE DATA SUGGEST AN IMPORTANT ROLE OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION IN LENTIVIRAL INFECTION. TO ELUCIDATE THE MECHANISM OF THIS SUPPRESSION, WE PREVIOUSLY REPORTED THAT DECREASED METHYLATION FACILITATES FOXP3 BINDING IN MITOGEN-ACTIVATED CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS (FIV)-INFECTED CATS. WE DEMONSTRATED THE REDUCED BINDING OF FOXP3 TO THE IL-2 PROMOTER BY INCREASING METHYLATION OF CD8(+) T CELLS. IN THE STUDIES PRESENTED HERE, WE ASK IF ANOTHER FORM OF EPIGENETIC MODULATION MIGHT ALLEVIATE FOXP3-MEDIATED SUPPRESSION IN CD8(+) T CELLS. WE HYPOTHESIZED THAT DECREASING HISTONE ACETYLATION IN VIRUS-SPECIFIC CD8(+) T CELLS WOULD DECREASE TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER. INDEED, USING ANACARDIC ACID (AA), A KNOWN HISTONE ACETYL TRANSFERASE (HAT) INHIBITOR, WE DEMONSTRATE A REDUCTION IN FOXP3 BINDING TO THE IL-2 PROMOTER IN VIRUS-SPECIFIC CD8(+) T CELLS CO-CULTURED WITH AUTOLOGOUS TREG CELLS. THESE DATA IDENTIFY A NOVEL MECHANISM OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION DURING LENTIVIRAL INFECTION. 2018