1 5867 101 SUPPRESSIVE EFFECT OF THE HISTONE DEACETYLASE INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) ON HEPATITIS C VIRUS REPLICATION. THE HISTONE DEACETYLASE (HDAC) INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) HAS A CLINICAL PROMISE FOR TREATMENT OF CANCER INCLUDING HEPATOCELLULAR CARCINOMA (HCC). TO INVESTIGATE EFFECT OF SAHA ON HEPATITIS C VIRUS (HCV) REPLICATION, WE TREATED THE HCV REPLICON CELL OR6 WITH SAHA. HCV REPLICATION WAS SIGNIFICANTLY INHIBITED BY SAHA AT CONCENTRATIONS BELOW 1 MUM WITH NO CELLULAR TOXICITY. ANOTHER HDAC INHIBITOR, TRICOSTATIN A, ALSO SHOWED REDUCTION OF HCV REPLICATION. THE MICROARRAY ANALYSIS AND QUANTITATIVE RT-PCR DEMONSTRATED UP-REGULATION OF OSTEOPONTIN (OPN) AND DOWN-REGULATION OF APOLIPOPROTEIN-A1 (APO-A1) AFTER SAHA TREATMENT. DIRECT GENE INDUCTION OF OPN AND KNOCKDOWN OF APO-A1 ALSO SHOWED REDUCTION OF HCV REPLICATION. THE LIVER SPECIFIC MICRORNA-122, WHICH IS INVOLVED IN HCV REPLICATION, WAS NOT AFFECTED BY SAHA TREATMENT. THESE RESULTS SUGGEST THAT SAHA HAS SUPPRESSIVE EFFECT ON HCV REPLICATION THROUGH ALTERATIONS OF GENE EXPRESSION SUCH AS OPN AND APO-A1 IN HOST CELLS. EPIGENETIC TREATMENT WITH HDAC INHIBITORS MAY BE A NOVEL THERAPEUTIC APPROACH FOR DISEASES ASSOCIATED WITH HCV INFECTION SUCH AS CHRONIC HEPATITIS, LIVER CIRRHOSIS, AND HCC. 2013 2 819 34 CHARACTERIZATION OF A KDM5 SMALL MOLECULE INHIBITOR WITH ANTIVIRAL ACTIVITY AGAINST HEPATITIS B VIRUS. CHRONIC HEPATITIS B (CHB) IS A GLOBAL HEALTH CARE CHALLENGE AND A MAJOR CAUSE OF LIVER DISEASE. TO FIND NEW THERAPEUTIC AVENUES WITH A POTENTIAL TO FUNCTIONALLY CURE CHRONIC HEPATITIS B VIRUS (HBV) INFECTION, WE PERFORMED A FOCUSED SCREEN OF EPIGENETIC MODIFIERS TO IDENTIFY POTENTIAL INHIBITORS OF REPLICATION OR GENE EXPRESSION. FROM THIS WORK WE IDENTIFIED ISONICOTINIC ACID INHIBITORS OF THE HISTONE LYSINE DEMETHYLASE 5 (KDM5) WITH POTENT ANTI-HBV ACTIVITY. TO ENHANCE THE CELLULAR PERMEABILITY AND LIVER ACCUMULATION OF THE MOST POTENT KDM5 INHIBITOR IDENTIFIED (GS-080) AN ESTER PRODRUG WAS DEVELOPED (GS-5801) THAT RESULTED IN IMPROVED BIOAVAILABILITY AND LIVER EXPOSURE AS WELL AS AN INCREASED H3K4ME3:H3 RATIO ON CHROMATIN. GS-5801 TREATMENT OF HBV-INFECTED PRIMARY HUMAN HEPATOCYTES REDUCED THE LEVELS OF HBV RNA, DNA AND ANTIGEN. EVALUATION OF GS-5801 ANTIVIRAL ACTIVITY IN A HUMANIZED MOUSE MODEL OF HBV INFECTION, HOWEVER, DID NOT RESULT IN ANTIVIRAL EFFICACY, DESPITE ACHIEVING PHARMACODYNAMIC LEVELS OF H3K4ME3:H3 PREDICTED TO BE EFFICACIOUS FROM THE IN VITRO MODEL. HERE WE DISCUSS POTENTIAL REASONS FOR THE DISCONNECT BETWEEN IN VITRO AND IN VIVO EFFICACY, WHICH HIGHLIGHT THE TRANSLATIONAL DIFFICULTIES OF EPIGENETIC TARGETS FOR VIRAL DISEASES. 2022 3 3728 30 INHIBITION OF REPLICATION OF HEPATITIS B VIRUS USING TRANSCRIPTIONAL REPRESSORS THAT TARGET THE VIRAL DNA. BACKGROUND: CHRONIC INFECTION WITH HEPATITIS B VIRUS (HBV) IS A SERIOUS GLOBAL HEALTH PROBLEM. PERSISTENCE OF THE VIRUS OCCURS AS A RESULT OF STABILITY OF THE REPLICATION INTERMEDIATE COMPRISING COVALENTLY CLOSED CIRCULAR DNA (CCCDNA). DEVELOPMENT OF DRUGS THAT ARE CAPABLE OF DISABLING THIS CCCDNA IS VITAL. METHODS: TO INVESTIGATE AN EPIGENETIC APPROACH TO INACTIVATING VIRAL DNA, WE ENGINEERED TRANSCRIPTIONAL REPRESSORS THAT COMPRISE AN HBV DNA-BINDING DOMAIN OF TRANSCRIPTION ACTIVATOR LIKE EFFECTORS (TALES) AND A FUSED KRUPPEL ASSOCIATED BOX (KRAB). THESE REPRESSOR TALES (RTALES) TARGETED THE VIRAL SURFACE OPEN READING FRAME AND WERE PLACED UNDER TRANSCRIPTION CONTROL OF CONSTITUTIVELY ACTIVE OR LIVER-SPECIFIC PROMOTERS. RESULTS: EVALUATION IN CULTURED CELLS AND FOLLOWING HYDRODYNAMIC INJECTION OF MICE REVEALED THAT THE RTALES SIGNIFICANTLY INHIBITED PRODUCTION OF MARKERS OF HBV REPLICATION WITHOUT EVIDENCE OF HEPATOTOXICITY. INCREASED METHYLATION OF HBV DNA AT CPG ISLAND II SHOWED THAT THE RTALES CAUSED INTENDED EPIGENETIC MODIFICATION. CONCLUSIONS: EPIGENETIC MODIFICATION OF HBV DNA IS A NEW AND EFFECTIVE MEANS OF INACTIVATING THE VIRUS IN VIVO. THE APPROACH HAS THERAPEUTIC POTENTIAL AND AVOIDS POTENTIALLY PROBLEMATIC UNINTENDED MUTAGENESIS OF GENE EDITING. 2019 4 3195 37 HDAC INHIBITORS AUGMENTED CELL MIGRATION AND METASTASIS THROUGH INDUCTION OF PKCS LEADING TO IDENTIFICATION OF LOW TOXICITY MODALITIES FOR COMBINATION CANCER THERAPY. PURPOSE: HISTONE DEACETYLASE INHIBITORS (HDACI) ARE ACTIVELY EXPLORED AS NEW-GENERATION EPIGENETIC DRUGS BUT HAVE LOW EFFICACY IN CANCER MONOTHERAPY. TO REVEAL NEW MECHANISM FOR COMBINATION THERAPY, WE SHOW THAT HDACI INDUCE CELL DEATH BUT SIMULTANEOUSLY ACTIVATE TUMOR-PROGRESSIVE GENES TO RUIN THERAPEUTIC EFFICACY. COMBINED TREATMENTS TO TARGET TUMORIGENESIS AND HDACI-ACTIVATED METASTASIS WITH LOW TOXIC MODALITIES COULD DEVELOP NEW STRATEGIES FOR LONG-TERM CANCER THERAPY. EXPERIMENTAL DESIGN: BECAUSE METASTASIS IS THE MAJOR CAUSE OF CANCER MORTALITY, WE MEASURED CELL MIGRATION ACTIVITY AND PROFILED METASTASIS-RELATED GENE EXPRESSIONS IN HDACI-TREATED CANCER CELLS. WE DEVELOPED LOW TOXIC COMBINATION MODALITIES TARGETING TUMORIGENESIS AND HDACI-ACTIVATED METASTASIS FOR PRECLINICAL THERAPIES IN MICE. RESULTS: WE SHOWED THAT CELL MIGRATION ACTIVITY WAS DRAMATICALLY AND DOSE DEPENDENTLY ENHANCED BY VARIOUS CLASSES OF HDACI TREATMENTS IN 13 OF 30 EXAMINED HUMAN BREAST, GASTRIC, LIVER, AND LUNG CANCER CELL LINES. TUMOR METASTASIS WAS ALSO ENHANCED IN HDACI-TREATED MICE. HDACI TREATMENTS ACTIVATED MULTIPLE PKCS AND DOWNSTREAM SUBSTRATES ALONG WITH UPREGULATED PROAPOPTOTIC P21. FOR TARGETING TUMORIGENESIS AND METASTASIS WITH IMMEDIATE CLINICAL IMPACT, WE SHOWED THAT NEW MODALITIES OF HDACI COMBINED DRUGS WITH PKC INHIBITORY AGENT, CURCUMIN OR TAMOXIFEN, NOT ONLY SUPPRESSED HDACI-ACTIVATED TUMOR PROGRESSIVE PROTEINS AND CELL MIGRATION IN VITRO BUT ALSO INHIBITED TUMOR GROWTH AND METASTASIS IN VIVO. CONCLUSION: TREATMENTS OF DIFFERENT STRUCTURAL CLASSES OF HDACI SIMULTANEOUSLY INDUCED CELL DEATH AND PROMOTED CELL MIGRATION AND METASTASIS IN MULTIPLE CANCER CELL TYPES. SUPPRESSION OF HDACI-INDUCED PKCS LEADS TO DEVELOPMENT OF LOW TOXIC AND LONG-TERM THERAPEUTIC STRATEGIES TO POTENTIALLY TREAT CANCER AS A CHRONIC DISEASE. 2012 5 1615 26 DNA METHYLTRANSFERASE 3B PLAYS A PROTECTIVE ROLE AGAINST HEPATOCARCINOGENESIS CAUSED BY CHRONIC INFLAMMATION VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. MOST HEPATOCELLULAR CARCINOMAS (HCCS) DEVELOP ON THE BASIS OF CHRONIC HEPATITIS, BUT THE MECHANISM OF EPIGENETIC REGULATION IN INFLAMMATORY HEPATOCARCINOGENESIS HAS YET TO BE ELUCIDATED. AMONG DE NOVO DNA METHYLTRANSFERASES (DNMTS), DNMT3B HAS LATELY BEEN REPORTED TO ACT SPECIFICALLY ON ACTIVELY TRANSCRIBED GENES, SUGGESTING THE POSSIBILITY THAT IT PLAYS A ROLE IN THE PATHOGENESIS OF CANCER. WE CONFIRMED THAT DNMT3B ISOFORMS LACKING ITS CATALYTIC DOMAIN WERE HIGHLY EXPRESSED IN HCCS COMPARED WITH NON-TUMOROUS LIVER TISSUE. TO ELUCIDATE THE ROLE OF DNMT3B IN HEPATOCARCINOGENESIS, WE GENERATED A GENETICALLY ENGINEERED MOUSE MODEL WITH HEPATOCYTE-SPECIFIC DNMT3B DELETION. THE LIVER OF THE DNMT3B-DEFICIENT MICE EXHIBITED AN EXACERBATION OF THIOACETAMIDE-INDUCED HEPATITIS, PROGRESSION OF LIVER FIBROSIS AND A HIGHER INCIDENCE OF HCC COMPARED WITH THE LIVER OF THE CONTROL MICE. WHOLE-GENOME BISULFITE SEQUENCING VERIFIED A LOWER CG METHYLATION LEVEL IN THE DNMT3B-DEFICIENT LIVER, DEMONSTRATING DIFFERENTIALLY METHYLATED REGIONS THROUGHOUT THE GENOME. TRANSCRIPTOME ANALYSIS REVEALED DECREASED EXPRESSION OF GENES RELATED TO OXIDATIVE PHOSPHORYLATION IN THE DNMT3B-DEFICIENT LIVER. MOREOVER, PRIMARY HEPATOCYTES ISOLATED FROM THE DNMT3B-DEFICIENT MICE SHOWED REDUCED MITOCHONDRIAL RESPIRATORY CAPACITY, LEADING TO THE ENHANCEMENT OF OXIDATIVE STRESS IN THE LIVER TISSUE. OUR FINDINGS SUGGEST THE PROTECTIVE ROLE OF DNMT3B AGAINST CHRONIC INFLAMMATION AND HCC DEVELOPMENT VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. 2020 6 3247 31 HEPATITIS B VIRUS BASAL CORE PROMOTER MUTATIONS SHOW LOWER REPLICATION FITNESS ASSOCIATED WITH CCCDNA ACETYLATION STATUS. IN CHRONIC HEPATITIS B VIRUS (HBV) INFECTION, VARIANTS WITH MUTATIONS IN THE BASAL CORE PROMOTER (BCP) AND PRECORE REGION PREDOMINATE AND ASSOCIATE WITH MORE SEVERE DISEASE FORMS. STUDIES ON THEIR EFFECT ON VIRAL REPLICATION REMAIN CONTROVERSIAL. INCREASING EVIDENCE SHOWS THAT EPIGENETIC MODIFICATIONS OF CCCDNA REGULATE HBV REPLICATION AND DISEASE OUTCOME. HERE WE DETERMINED THE TRANSCRIPTION AND VIRAL REPLICATION EFFICIENCY OF WELL-DEFINED BCP AND PRECORE MUTATIONS AND THEIR EFFECT ON CCCDNA EPIGENETIC CONTROL. HBV MONOMERS BEARING BCP MUTATIONS A1762T/G1764A AND A1762T/G1764A/C1766T, AND PRECORE MUTATIONS G1896A, G1899A AND G1896A/G1899A, WERE TRANSFECTED INTO HEPG2 CELLS USING A PLASMID-FREE APPROACH. VIRAL RNA TRANSCRIPTS WERE DETECTED BY NORTHERN BLOT HYBRIDIZATION AND RT PCR, DNA REPLICATIVE INTERMEDIATES BY SOUTHERN BLOTTING AND RT PCR, AND VIRAL RELEASE WAS MEASURED BY ELISA. ACETYLATION OF CCCDNA-BOUND HISTONES WAS ASSESSED BY CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY AND METHYLATION OF CCCDNA BY BISULFITE SEQUENCING. BCP MUTATIONS RESULTED IN LOW VIRAL RELEASE, MRNA TRANSCRIPTION AND PGRNA/CCCDNA RATIOS THAT PARALLELED THE ACETYLATION OF CCCDNA-BOUND H4 HISTONE AND INVERSELY CORRELATED WITH THE HDAC1 RECRUITMENT ONTO CCCDNA. INDEPENDENTLY OF THE MUTATIONS, CCCDNA WAS A TARGET FOR METHYLATION, ACCOMPANIED BY THE UPREGULATION OF DNMT1 EXPRESSION AND DNMT1 RECRUITMENT ONTO CCCDNA. OUR RESULTS SUGGEST THAT BCP MUTATIONS DECREASE VIRAL REPLICATION CAPACITY POSSIBLY BY MODULATING THE ACETYLATION AND DEACETYLATION OF CCCDNA-BOUND HISTONES WHILE PRECORE MUTATIONS DO NOT HAVE A SIGNIFICANT EFFECT ON VIRAL REPLICATION. THESE DATA PROVIDE EVIDENCE THAT EPIGENETIC FACTORS CONTRIBUTE TO THE REGULATION OF HBV VIRAL REPLICATION. 2016 7 4877 42 OVEREXPRESSION OF MIR-4433 BY SUBEROYLANILIDE HYDROXAMIC ACID SUPPRESSES GROWTH OF CML CELLS AND INDUCES APOPTOSIS THROUGH TARGETING BCR-ABL. BACKGROUND: TARGETING BCR-ABL IS THE KEY FOR THE TREATMENT OF CML. ALTHOUGH GREAT PROGRESS HAS BEEN ACHIEVED FOR THE TREATMENT OF CML PATIENTS IN CHRONIC STAGE, EFFECTIVE DRUGS WITH GOOD SAFETY ARE NOT AVAILABLE FOR THOSE IN ADVANCED STAGES OF CML PATIENTS. IN PRESENT STUDY, A HISTONE DEACETYLASE INHIBITOR, SUBEROYLANILIDE HYDROXAMIC ACID (SAHA), WAS USED TO SCREEN FOR MICRORNA THAT CAN TARGET BCR-ABL. METHODS: RT-QPCR WAS USED TO DETERMINE BCR-ABL AND MIR-4433 TRANSCRIPTION LEVEL IN CML CELLS. IN CML CELLS, PROTEINS INCLUDING PARP, CASPASE-3, ACETYL-HISTONE 3, HISTONE 3 AND BCR-ABL, AS WELL AS BCR-ABL DOWNSTREAM PROTEINS WERE DETECTED USING WESTERN BLOT. CELL VIABILITY AND APOPTOSIS WERE MONITORED RESPECTIVELY BY MTS ASSAY AND FLOW CYTOMETRY. THE CORRELATION BETWEEN MIR-4433 AND BCR-ABL WAS DETERMINED BY LUCIFERASE REPORTER ASSAY. THE ANTI-TUMOR EFFECT OF MIR-4433 TO K562 CELLS WAS EVALUATED BY NUDE MOUSE XENOGRAFT MODEL IN VIVO. RESULTS: SAHA UP-REGULATED THE ACETYLATION LEVEL OF HISTONE 3, AND EFFECTIVELY INHIBITED BCR-ABL MRNA LEVEL AND ITS DOWNSTREAM SIGNAL TRANSDUCTION PATHWAY, WHILE INHIBITING THE GROWTH OF CML CELLS AND INDUCING APOPTOSIS. FURTHERMORE, BIOINFORMATICS TOOLS PREDICTED THAT MIR-4433 IS A PUTATIVE MICRORNA TARGETING BCR-ABL AND THAT THE EXPRESSION LEVEL OF MIR-4433 WAS SIGNIFICANTLY INCREASED AFTER SAHA TREATMENT IN K562 CELLS. LUCIFERASE ACTIVITY ANALYSIS REVEALED THAT MIR-4433 DIRECTLY TARGETS BCR-ABL. ADDITIONALLY, TRANSIENT EXPRESSION OF MIR-4433 ABROGATED BCR-ABL ACTIVITY AND ITS DOWNSTREAM SIGNALING PATHWAYS WHILE INDUCING APOPTOSIS IN K562 CELLS. MOREOVER, STABLE EXPRESSION OF MIR-4433 SUPPRESSED BCR-ABL AND ITS DOWNSTREAM SIGNALING PATHWAY, AND INHIBITED THE GROWTH OF K562 CELLS IN VITRO AND THE GROWTH OF K562-XENOGRAFTS IN NUDE MICE. CONCLUSION: MIR-4433 WAS IDENTIFIED AS A MICRORNA TARGETING BCR-ABL, WHICH MAY BE SUBJECT TO EPIGENETIC REGULATION OF SAHA, A HISTONE DEACETYLASE INHIBITOR THAT HAS BEEN APPROVED BY THE US FDA FOR THE TREATMENT OF CUTANEOUS T-CELL LYMPHOMA. THE FINDINGS OF THIS STUDY PROVIDE A MOLECULAR BASIS FROM ANOTHER ANGLE FOR THE USE OF SAHA IN THE TREATMENT OF CML. 2019 8 3660 38 INDUCTION OF HEPATIC DIFFERENTIATION OF MOUSE BONE MARROW STROMAL STEM CELLS BY THE HISTONE DEACETYLASE INHIBITOR VPA. BONE MARROW STROMAL STEM CELLS (BMSSCS) MAY HAVE POTENTIAL TO DIFFERENTIATE IN VITRO AND IN VIVO INTO HEPATOCYTES. HERE, WE INVESTIGATED THE EFFECTS OF VALPROIC ACID (VPA) INVOLVED IN EPIGENETIC MODIFICATION, A DIRECT INHIBITOR OF HISTONE DEACETYLASE, ON HEPATIC DIFFERENTIATION OF MOUSE BMSSCS. FOLLOWING THE TREATMENT OF 2.5 MM VPA FOR 72 HRS, THE IN VITRO EXPANDED, HIGHLY PURIFIED AND FUNCTIONALLY ACTIVE MOUSE BMSSCS FROM BONE MARROW WERE EITHER EXPOSED TO SOME WELL-DEFINED CYTOKINES AND GROWTH FACTORS IN A SEQUENTIAL WAY (FIBROBLAST GROWTH FACTOR-4 [FGF-4], FOLLOWED BY HGF, AND HGF + OSM + ITS + DEXAMETHASONE, RESEMBLING THE ORDER OF SECRETION DURING LIVER EMBRYOGENESIS) OR TRANSPLANTED (CAUDAL VEIN) IN MICE SUBMITTED TO A PROTOCOL OF CHRONIC INJURY (CHRONIC I.P. INJECTION OF CCL4). ADDITIONAL EXPOSURE OF THE CELLS TO VPA CONSIDERABLY IMPROVED THE IN VITRO DIFFERENTIATION, AS DEMONSTRATED BY A MORE HOMOGENEOUS CELL POPULATION EXHIBITED EPITHELIAL MORPHOLOGY, INCREASING EXPRESSION OF HEPATIC SPECIAL GENES AND ENHANCED HEPATIC FUNCTIONS. FURTHER MORE, IN VIVO RESULTS INDICATE THAT THE PRE-TREATMENT OF VPA SIGNIFICANTLY INCREASED THE HOMING EFFICIENCY OF BMSSCS TO THE SITE OF LIVER INJURY AND, ADDITIONALLY, FOR SUPPORTING HEPATIC DIFFERENTIATION AS WELL AS IN VITRO. WE HAVE DEMONSTRATED THE USEFULNESS OF VPA IN THE TRANSDIFFERENTIATION OF BMSSCS INTO HEPATOCYTES BOTH IN VITRO AND IN VIVO, AND REGULATION OF FIBROBLAST GROWTH FACTOR RECEPTORS (FGFRS) AND C-MET GENE EXPRESSION THROUGH POST-TRANSLATIONAL MODIFICATION OF CORE HISTONES MIGHT BE THE PRIMARY INITIATING EVENT FOR THESE EFFECTS. THIS MODE COULD BE HELPFUL FOR LIVER ENGINEERING AND CLINICAL THERAPY. 2009 9 6421 40 THE THERAPEUTIC PROPERTIES OF RESMINOSTAT FOR HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON FORM OF PRIMARY LIVER CANCER WITH INCREASES IN NEW CASES BEING REPORTED ANNUALLY. HISTOPATHOLOGISTS HAVE IDENTIFIED HEPATIC STEATOSIS AS A CHARACTERISTIC OF A BROAD RANGE OF CHRONIC LIVER DISEASES THAT ARE ASSOCIATED WITH THE ONSET AND DEVELOPMENT OF HCC. IN THIS CONTEXT, EPIGENETIC MODIFICATIONS MAY SERVE AS PRECANCEROUS FACTORS PREDISPOSING NORMAL CELLS TO THE INITIATION OF CARCINOGENESIS. THIS STUDY DEMONSTRATED THAT HEPATIC TUMORIGENESIS AND DIFFERENTIATED ADIPOCYTES MAY MODULATE BOTH GLOBAL HISTONE DEACETYLASE (HDAC) EXPRESSION AND SPECIFIC CLASS I HDAC GENES IN THE TUMOUR MICROENVIRONMENT. THE NOVEL CLASS I HDAC INHIBITOR RESMINOSTAT WAS SHOWN TO REDUCE THE PROLIFERATION OF HCC CELLS ALONG WITH ITS SPECIFICITY IN TARGETING CLASS I HDACS AND ONCOGENES. THE COMBINED EFFECT OF RESMINOSTAT WITH SEVERAL PHARMACEUTICAL AGENTS SUCH AS SORAFENIB, CISPLATIN AND DOXORUBICIN WAS ALSO DEMONSTRATED. THE INHIBITION OF HEAT SHOCK PROTEIN 90 (HSP90) HAS BEEN DEMONSTRATED AS A POTENTIAL THERAPEUTIC OPTION FOR HCC. IN LINE WITH THIS, THE SPECIFIC HSP90 INHIBITOR 17-(ALLYLAMINO)-17-DEMETHOXYGELDANAMYCIN (17-AAG) WAS SELECTED AND IT WAS FOUND THAT THE COMBINATION OF RESMINOSTAT AND 17-AAG MAY PROVIDE A "SMART" CLINICAL STRATEGY FOR HCC PATIENTS BY TARGETING CELLULAR COMMUNICATION WITHIN THE TUMOUR MICROENVIRONMENT. THIS STUDY PROVIDES AN INSIGHT INTO THE USE OF RESMINOSTAT AS AN EPIGENETIC BASED THERAPEUTIC FOR HCC ALONG WITH OTHER PHARMACEUTICAL OPTIONS, IN PARTICULAR BY TARGETING THE CELL-TO-CELL COMMUNICATION THAT OCCURS BETWEEN HEPATOMA AND ADIPOCYTES. 2018 10 3261 35 HEPATITIS C VIRUS-INDUCED UP-REGULATION OF PROTEIN PHOSPHATASE 2A INHIBITS HISTONE MODIFICATION AND DNA DAMAGE REPAIR. THE MOLECULAR MECHANISMS UNDERLYING HEPATOCARCINOGENESIS IN CHRONIC VIRAL HEPATITIS ARE POORLY UNDERSTOOD. A POTENTIAL TUMORIGENIC PATHWAY COULD INVOLVE PROTEIN PHOSPHATASE 2A (PP2A) AND PROTEIN ARGININE METHYLTRANSFERASE 1 (PRMT1), BECAUSE BOTH ENZYMES ARE DYSREGULATED IN CHRONIC HEPATITIS C, AND BOTH ENZYMES HAVE BEEN INVOLVED IN CHROMATIN REMODELING AND DNA DAMAGE REPAIR. WE USED CELL LINES THAT ALLOW THE INDUCIBLE EXPRESSION OF HEPATITIS C VIRUS PROTEINS (UHCV57.3) AND OF THE CATALYTIC SUBUNIT OF PP2A (UPP2A-C8) AS WELL AS HUH7.5 CELLS INFECTED WITH RECOMBINANT CELL CULTURE-DERIVED HEPATITIS C VIRUS (HCVCC) TO STUDY EPIGENETIC HISTONE MODIFICATIONS AND DNA DAMAGE REPAIR. THE INDUCTION OF VIRAL PROTEINS, THE OVEREXPRESSION OF PP2AC, OR THE INFECTION OF HUH7.5 CELLS WITH HCVCC RESULTED IN AN INHIBITION OF HISTONE H4 METHYLATION/ACETYLATION AND HISTONE H2AX PHOSPHORYLATION, IN A SIGNIFICANTLY CHANGED EXPRESSION OF GENES IMPORTANT FOR HEPATOCARCINOGENESIS, AND INHIBITED DNA DAMAGE REPAIR. OVEREXPRESSION OF PP2AC IN NIH-3T3 CELLS INCREASED ANCHORAGE-INDEPENDENT GROWTH. THESE CHANGES WERE PARTIALLY REVERSED BY THE TREATMENT OF CELLS WITH THE METHYL-GROUP DONOR S-ADENOSYL-L-METHIONINE (SAME). CONCLUSION: HEPATITIS C VIRUS-INDUCED OVEREXPRESSION OF PP2AC CONTRIBUTES TO HEPATOCARCINOGENESIS THROUGH DYSREGULATION OF EPIGENETIC HISTONE MODIFICATIONS. THE CORRECTION OF DEFECTIVE HISTONE MODIFICATIONS BY S-ADENOSYL-L-METHIONINE MAKES THIS DRUG A CANDIDATE FOR CHEMOPREVENTIVE THERAPIES IN PATIENTS WITH CHRONIC HEPATITIS C WHO ARE AT RISK FOR DEVELOPING HEPATOCELLULAR CARCINOMA. 2010 11 2837 33 FORKHEAD O TRANSCRIPTION FACTOR 4 RESTRICTS HBV COVALENTLY CLOSED CIRCULAR DNA TRANSCRIPTION AND HBV REPLICATION THROUGH GENETIC DOWNREGULATION OF HEPATOCYTE NUCLEAR FACTOR 4 ALPHA AND EPIGENETIC SUPPRESSION OF COVALENTLY CLOSED CIRCULAR DNA VIA INTERACTING WITH PROMYELOCYTIC LEUKEMIA PROTEIN. NUCLEAR LOCATED HEPATITIS B VIRUS (HBV) COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) REMAINS THE KEY OBSTACLE TO CURE CHRONIC HEPATITIS B (CHB). IN OUR PREVIOUS INVESTIGATION, IT WAS FOUND THAT FOXO4 COULD INHIBIT HBV CORE PROMOTER ACTIVITY THROUGH DOWNREGULATING THE EXPRESSION OF HNF4ALPHA. HOWEVER, THE EXACT MECHANISMS WHEREBY FOXO4 INHIBITS HBV REPLICATION, ESPECIALLY ITS EFFECT ON CCCDNA, REMAIN UNCLEAR. HERE, OUR DATA FURTHER REVEALED THAT FOXO4 COULD EFFECTIVELY INHIBIT CCCDNA MEDIATED TRANSCRIPTION AND HBV REPLICATION WITHOUT AFFECTING CCCDNA LEVEL. MECHANISTIC STUDY SHOWED THAT FOXO4 COULD CAUSE EPIGENETIC SUPPRESSION OF CCCDNA. ALTHOUGH FOXO4-MEDIATED DOWNREGULATION OF HNF4ALPHA CONTRIBUTED TO INHIBITING HBV CORE PROMOTER ACTIVITY, IT HAD LITTLE EFFECT ON CCCDNA EPIGENETIC REGULATION. FURTHER, IT WAS FOUND THAT FOXO4 COULD COLOCALIZE WITHIN PROMYELOCYTIC LEUKEMIA PROTEIN (PML) NUCLEAR BODIES AND INTERACT WITH PML. OF NOTE, PML WAS REVEALED TO BE CRITICAL FOR FOXO4-MEDIATED INHIBITION OF CCCDNA EPIGENETIC MODIFICATION AND OF THE FOLLOWING CCCDNA TRANSCRIPTION AND HBV REPLICATION. FURTHERMORE, FOXO4 WAS FOUND TO BE DOWNREGULATED IN HBV-INFECTED HEPATOCYTES AND HUMAN LIVER TISSUES, AND IT WAS NEGATIVELY CORRELATED WITH CCCDNA TRANSCRIPTIONAL ACTIVITY IN CHB PATIENTS. TOGETHER, THESE FINDINGS HIGHLIGHT THE ROLE OF FOXO4 IN SUPPRESSING CCCDNA TRANSCRIPTION AND HBV REPLICATION VIA GENETIC DOWNREGULATION OF HNF4ALPHA AND EPIGENETIC SUPPRESSION OF CCCDNA THROUGH INTERACTING WITH PML. TARGETING FOXO4 MAY PRESENT AS A NEW THERAPEUTIC STRATEGY AGAINST CHRONIC HBV INFECTION. IMPORTANCE HBV CCCDNA IS A DETERMINING FACTOR FOR VIRAL PERSISTENCE AND THE MAIN OBSTACLE FOR A CURE OF CHRONIC HEPATITIS B. STRATEGIES THAT TARGET CCCDNA DIRECTLY ARE THEREFORE OF GREAT IMPORTANCE IN CONTROLLING PERSISTENT HBV INFECTION. IN PRESENT INVESTIGATION, WE FOUND THAT FOXO4 COULD EFFICIENTLY SUPPRESS CCCDNA TRANSCRIPTION AND HBV REPLICATION WITHOUT AFFECTING THE LEVEL OF CCCDNA ITSELF. FURTHER, OUR DATA REVEALED THAT FOXO4 MIGHT INHIBIT CCCDNA FUNCTION VIA A TWO-PART MECHANISM: ONE IS TO EPIGENETICALLY SUPPRESS CCCDNA TRANSCRIPTION VIA INTERACTING WITH PML, AND THE OTHER IS TO INHIBIT HBV CORE PROMOTER ACTIVITY VIA THE GENETIC DOWNREGULATION OF HNF4ALPHA. OF NOTE, HBV MIGHT DAMPEN THE EXPRESSION OF FOXO4 FOR ITS OWN PERSISTENT INFECTION. WE PROPOSE THAT MANIPULATION OF FOXO4 MAY PRESENT AS A POTENTIAL THERAPEUTIC STRATEGY AGAINST CHRONIC HBV INFECTION. 2022 12 3948 32 LNCRNA-CD160 DECREASES THE IMMUNITY OF CD8(+) T CELLS THROUGH EPIGENETIC MECHANISMS IN HEPATITIS B VIRUS INFECTION. THE TRANSFER AND DEVELOPMENT OF CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IS ASSOCIATED WITH THE T CELL IMMUNE RESPONSE, THEREFORE INVESTIGATING THE KEY REGULATORS OF CELL IMMUNE RESPONSE IS NEEDED TO IMPROVE CHRONIC HBV TREATMENT. BLOOD SAMPLES FROM PATIENTS WITH CHRONIC HBV INFECTION WERE USED TO CONFIRM THE CORRELATION BETWEEN HBV INFECTION STAGE AND CD160 RECEPTOR EXPRESSION LEVELS IN CD8(+) T CELLS, THE CD8(+) T CELLS ARE USED TO RESEARCH THE MECHANISM OF T CELL IMMUNE RESPONSE MODULATION, MOREOVER, C3H/HEN MICE WITH REDUCED CD160 EXPRESSION LEVELS WERE USED TO INVESTIGATE THE ASSOCIATION BETWEEN LONG NON-CODING (LNC)RNA-CD160 AND HBV INFECTION. LONG NON-CODING (LNC)RNA-CD160 AND HISTONE-MODIFICATION ENZYME GENE HISTONE DEACETYLASE 11 (HDAC11) EXPRESSION LEVELS WERE NEGATIVELY ASSOCIATED WITH CD160 EXPRESSION. LNCRNA-CD160 CAN INHIBIT THE SECRETION OF IFN-GAMMA AND TNF-ALPHA THROUGH HDAC11 RECRUITMENT AND BIND TO HDAC11 TO FORM A COMPLEX ON THE PROMOTERS OF IFN-GAMMA AND TNF-ALPHA. THE HDAC11, IFN-GAMMA AND TNF-ALPHA FORM A COMPLEX AND ENHANCE THE METHYLATION OF H3K9ME1, CHROMATIN CHANGES INTO THE HETEROCHROMATIN AND THE TRANSCRIPTION OF IFN-GAMMA AND TNF-ALPHA IS BLOCKED; MOREOVER, THE HDAC11/IFN-GAMMA/TNF-ALPHA COMPLEX CAN ALSO INHIBIT THE SECRETION OF IFN-GAMMA AND TNF-ALPHA IN CD160(-) CD8(+) T CELLS AND SUPPRESSES THE FUNCTION OF CD8(+) T CELLS. FURTHERMORE, SMALL INTERFERING RNA TARGETING LNCRNA-CD160 CAN BLOCK HBV INFECTION PROGRESSION. LNCRNA-CD160 ACTS AS AN IMMUNE SUPPRESSIVE FACTOR AND IS EXPRESSED AT A HIGH LEVEL IN PERIPHERAL BLOOD CD8(+) T CELLS OF HBV INFECTED PATIENTS. FURTHERMORE, HIGH EXPRESSION LEVELS OF LNCRNA-CD160 CAN CONTRIBUTE TO THE INHIBITION OF IFN-GAMMA AND TNF-ALPHA SECRETION IN CD8(+) T CELLS AND DECREASE THE IMMUNE RESPONSE OF CD8(+) T CELLS. THEREFORE, LNCRNA-CD160 MAY BECOME A NEW TARGET FOR IMMUNOTHERAPY OF CHRONIC HBV INFECTION IN THE FUTURE AND MAY PROVIDE A NEW THERAPEUTIC STRATEGY FOR THE TREATMENT OF HBV INFECTION. 2020 13 4771 33 NUCLEAR SENSOR INTERFERON-INDUCIBLE PROTEIN 16 INHIBITS THE FUNCTION OF HEPATITIS B VIRUS COVALENTLY CLOSED CIRCULAR DNA BY INTEGRATING INNATE IMMUNE ACTIVATION AND EPIGENETIC SUPPRESSION. BACKGROUND AND AIMS: NUCLEAR-LOCATED COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) OF HEPATITIS B VIRUS (HBV) IS A DETERMINING FACTOR FOR HBV PERSISTENCE AND THE KEY OBSTACLE FOR A CURE OF CHRONIC HEPATITIS B. HOWEVER, IT REMAINS UNCLEAR WHETHER AND HOW THE HOST IMMUNE SYSTEM SENSES HBV CCCDNA AND ITS BIOLOGICAL CONSEQUENCES. APPROACH AND RESULTS: HERE, WE DEMONSTRATED THAT INTERFERON-INDUCIBLE PROTEIN 16 (IFI16) COULD SERVE AS A UNIQUE INNATE SENSOR TO RECOGNIZE AND BIND TO HBV CCCDNA IN HEPATIC NUCLEI, LEADING TO THE INHIBITION OF CCCDNA TRANSCRIPTION AND HBV REPLICATION. MECHANISTICALLY, OUR DATA SHOWED THAT IFI16 PROMOTED THE EPIGENETIC SUPPRESSION OF HBV CCCDNA BY TARGETING AN INTERFERON-STIMULATED RESPONSE ELEMENT (ISRE) PRESENT IN CCCDNA. IT IS OF INTEREST THAT THIS ISRE WAS ALSO REVEALED TO PLAY AN IMPORTANT ROLE IN IFI16-ACTIVATED TYPE I INTERFERON RESPONSES. FURTHERMORE, OUR DATA REVEALED THAT HBV COULD DOWN-REGULATE THE EXPRESSION LEVEL OF IFI16 IN HEPATOCYTES, AND THERE WAS A NEGATIVE CORRELATION BETWEEN IFI16 AND HBV TRANSCRIPTS IN LIVER BIOPSIES, SUGGESTING THE POSSIBLE ROLE OF IFI16 IN SUPPRESSING CCCDNA FUNCTION UNDER PHYSIOLOGICAL CONDITIONS. CONCLUSIONS: THE NUCLEAR SENSOR IFI16 SUPPRESSES CCCDNA FUNCTION BY INTEGRATING INNATE IMMUNE ACTIVATION AND EPIGENETIC REGULATION BY TARGETING THE ISRE OF CCCDNA, AND IFI16 MAY PRESENT AS A THERAPEUTIC TARGET AGAINST HBV INFECTION. 2020 14 3330 31 HISTONE DEACETYLASE INHIBITOR GIVINOSTAT ALLEVIATES LIVER FIBROSIS BY REGULATING HEPATIC STELLATE CELL ACTIVATION. HEPATIC FIBROSIS, A COMMON PATHOLOGICAL MANIFESTATION OF CHRONIC LIVER INJURY, IS GENERALLY CONSIDERED TO BE THE END RESULT OF AN INCREASE IN EXTRACELLULAR MATRIX PRODUCED BY ACTIVATED HEPATIC STELLATE CELLS (HSCS). THE AIM OF THE PRESENT STUDY WAS TO TARGET THE MECHANISMS UNDERLYING HSC ACTIVATION IN ORDER TO PROVIDE A POWERFUL THERAPEUTIC STRATEGY FOR THE PREVENTION AND TREATMENT OF LIVER FIBROSIS. IN THE PRESENT STUDY, A HIGH?THROUGHPUT SCREENING ASSAY WAS ESTABLISHED, AND THE HISTONE DEACETYLASE INHIBITOR GIVINOSTAT WAS IDENTIFIED AS A POTENT INHIBITOR OF HSC ACTIVATION IN VITRO. GIVINOSTAT SIGNIFICANTLY INHIBITED HSC ACTIVATION IN VIVO, AMELIORATED CARBON TETRACHLORIDE?INDUCED MOUSE LIVER FIBROSIS AND LOWERED PLASMA AMINOTRANSFERASES. TRANSCRIPTOMIC ANALYSIS REVEALED THE MOST SIGNIFICANTLY REGULATED GENES IN THE GIVINOSTAT TREATMENT GROUP IN COMPARISON WITH THOSE IN THE SOLVENT GROUP, AMONG WHICH, DERMOKINE (DMKN), MESOTHELIN (MSLN) AND UROPLAKIN?3B (UPK3B) WERE IDENTIFIED AS POTENTIAL REGULATORS OF HSC ACTIVATION. GIVINOSTAT SIGNIFICANTLY REDUCED THE MRNA EXPRESSION OF DMKN, MSLN AND UPK3B IN BOTH A MOUSE LIVER FIBROSIS MODEL AND IN HSC?LX2 CELLS. KNOCKDOWN OF ANY OF THE AFOREMENTIONED GENES INHIBITED THE TGF?BETA1?INDUCED EXPRESSION OF ALPHA?SMOOTH MUSCLE ACTIN AND COLLAGEN TYPE I, INDICATING THAT THEY ARE CRUCIAL FOR HSC ACTIVATION. IN SUMMARY, USING A NOVEL STRATEGY TARGETING HSC ACTIVATION, THE PRESENT STUDY IDENTIFIED A POTENTIAL EPIGENETIC DRUG FOR THE TREATMENT OF HEPATIC FIBROSIS AND REVEALED NOVEL REGULATORS OF HSC ACTIVATION. 2021 15 5955 40 TELBIVUDINE TREATMENT CORRECTS HBV-INDUCED EPIGENETIC ALTERATIONS IN LIVER CELLS OF PATIENTS WITH CHRONIC HEPATITIS B. HEPATITIS B VIRUS (HBV) ALTERS THE EXPRESSION OF HOST CELLULAR GENES TO SUPPORT ITS REPLICATION AND SURVIVAL AND TO PROMOTE THE LIVER CELL INJURY. HOWEVER, THE UNDERLYING MECHANISM REMAINED INCOMPLETELY UNDERSTOOD. IN THIS STUDY, WE INVESTIGATED HBV-INDUCED EPIGENETIC CHANGES IN HEPG2 CELLS BY PROFILING THE LANDSCAPES OF THE ACTIVE HISTONE MODIFICATION MARK H3K4ME3 AND REPRESSIVE MARK H3K27ME3 USING CHROMATIN IMMUNOPRECIPITATION-SEQUENCING. HBV CAUSED THE ALTERED HISTONE MODIFICATIONS AT THOUSANDS OF GENOMIC LOCI, WHICH ARE CRITICALLY INVOLVED IN HBV ENTRY, INFLAMMATION, FIBROSIS AND CARCINOGENESIS OF HOST CELLS. INTERESTINGLY, TREATMENT OF THE HBV-TRANSFORMED HEPG2 CELLS WITH THE ANTI-HBV DRUG TELBIVUDINE SUBSTANTIALLY RESTORED THE H3K4ME3 LEVEL TO THAT OF UNTRANSFORMED HEPG2 CELLS. MORE IMPORTANTLY, OUR ANALYSIS OF LIVER SAMPLES FROM CONTROL AND CHRONIC HEPATITIS B PATIENTS REVEALED THAT TREATMENT OF THE PATIENTS WITH TELBIVUDINE NOT ONLY CORRECTED THE TARGET GENE EXPRESSION BUT ALSO THE EPIGENETIC MODIFICATION OF CRITICAL GENES. IN ADDITION, THE EXPRESSION OF THE HISTONE METHYLTRANSFERASES SMYD3 AND EZH2 THAT REGULATE HISTONE H3-SPECIFIC METHYLATION SHOWED NO DIFFERENCE IN HEPG2 CELL WITH OR WITHOUT HBV EXISTENCE. THUS, OUR DATA SUGGEST THAT ABNORMAL HISTONE MODIFICATIONS MIGHT CRITICALLY INVOLVED IN HBV-MEDIATED LIVER PATHOGENESIS AND TELBIVUDINE THERAPY MIGHT BENEFIT PATIENTS WITH HBV-RELATED CHRONIC INFECTION, LIVER CIRRHOSIS AND EVEN HEPATIC CARCINOMA. SUMMARY: TELBIVUDINE SUBSTANTIALLY RESTORES IN VITRO AND IN VIVO HBV-CAUSED ABNORMAL EXPRESSIONS AND HISTONE H3K4ME3 AND H3K27ME3 MODIFICATIONS AT THOUSANDS OF GENOMIC LOCI THAT ARE INVOLVED IN THE PATHOGENESIS OF LIVER CELLS, REVEALING A NOVEL MECHANISM FOR HBV-MEDIATED LIVER DAMAGE. 2014 16 3243 34 HEPATIC STEATOSIS IN HEPATITIS C IS A STORAGE DISEASE DUE TO HCV INTERACTION WITH MICROSOMAL TRIGLYCERIDE TRANSFER PROTEIN (MTP). LIVER STEATOSIS IS A FREQUENT HISTOLOGICAL FEATURE IN PATIENTS CHRONICALLY INFECTED WITH HEPATITIS C VIRUS (HCV). THE RELATIONSHIP BETWEEN HCV AND HEPATIC STEATOSIS SEEMS TO BE THE RESULT OF BOTH EPIGENETIC AND GENETIC FACTORS. IN VIVO AND IN VITRO STUDIES HAVE SHOWN THAT HCV CAN ALTER INTRAHEPATIC LIPID METABOLISM BY AFFECTING LIPID SYNTHESIS, OXIDATIVE STRESS, LIPID PEROXIDATION, INSULIN RESISTANCE AND THE ASSEMBLY AND SECRETION OF VLDL. MANY STUDIES SUGGEST THAT HCV-RELATED STEATOSIS MIGHT BE THE RESULT OF A DIRECT INTERACTION BETWEEN THE VIRUS AND MTP. IT HAS BEEN DEMONSTRATED THAT MTP IS CRITICAL FOR THE SECRETION OF HCV PARTICLES AND THAT INHIBITION OF ITS LIPID TRANSFER ACTIVITY REDUCES HCV PRODUCTION. HOWEVER, HIGHER DEGREES OF HEPATIC STEATOSIS WERE FOUND IN CHRONIC HEPATITIS C PATIENTS CARRYING THE T ALLELE OF MTP -493G/T POLYMORPHISM THAT SEEMS TO BE ASSOCIATED WITH INCREASED MTP TRANSCRIPTION. WE PROPOSE HERE THAT LIVER STEATOSIS IN HEPATITIS C COULD BE A STORAGE DISEASE INDUCED BY THE EFFECTS OF THE VIRUS AND OF ITS PROTEINS ON THE INTRACELLULAR LIPID MACHINERY AND ON MTP. AVAILABLE DATA SUPPORT THE HYPOTHESIS THAT HCV MAY MODULATE MTP EXPRESSION AND ACTIVITY THROUGH A NUMBER OF MECHANISMS SUCH AS INHIBITION OF ITS ACTIVITY AND TRANSCRIPTIONAL CONTROL. INITIAL UP REGULATION COULD FAVOUR PROPAGATION OF HCV WHILE DOWN REGULATION IN CHRONIC PHASE COULD CAUSE IMPAIRMENT OF TRIGLYCERIDE SECRETION AND EXCESSIVE LIPID ACCUMULATION, WITH ABNORMAL LIPID DROPLETS FACILITATING THE "STORAGE" OF VIRUS PARTICLES FOR PERSISTENT INFECTION. 2010 17 5844 38 STUDY OF PROMOTER HYPOMETHYLATION PROFILES OF RAS ONCOGENES IN HEPATOCELLULAR CARCINOMA DERIVED FROM HEPATITIS C VIRUS GENOTYPE 3A IN PAKISTANI POPULATION. EPIGENETIC MODIFICATIONS SUCH AS DNA METHYLATION CONTRIBUTE TO PROGRESSION OF HEPATITIS C VIRUS (HCV) INFECTION TO LIFE-THREATENING HEPATOCELLULAR CARCINOMA (HCC) BY PROMOTING THE SILENCING OF TUMOR SUPPRESSOR GENES THROUGH DNA HYPERMETHYLATION AND BY CAUSING GENOMIC INSTABILITY THROUGH GLOBAL HYPOMETHYLATION. HOWEVER FEW STUDIES HAVE ADDRESSED THE PROMOTER REGION HYPOMETHYLATION STATUS OF THE ONCOGENES INVOLVED IN HCV DERIVED HCC. IN THIS STUDY, WE ANALYZED THE PROMOTER REGION METHYLATION PATTERN OF RAS ONCOGENES (HRAS, KRAS, AND NRAS) USING METHYLATION-SPECIFIC PCR FOR 50 CHRONIC HCV PATIENTS INFECTED WITH GENOTYPE 3A (27 HCC PATIENTS AND 23 CONTROL NON-HCC PATIENTS). METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION ANALYSIS REVEALED THAT THE NRAS ONCOGENE PROMOTER (P = .0025) WAS SIGNIFICANTLY HYPOMETHYLATED IN HCC PATIENTS COMPARED TO THE NON-HCC PATIENTS SUGGESTING ITS CONTRIBUTION TO THE PROGRESSION OF HCV TOWARDS HCC. TO IDENTIFY THE AGENT FOR ALTERATION IN THE RAS ONCOGENE EXPRESSION, 7 HCV GENES WERE EXPRESSED IN THE HUH-7 CELL LINE FOLLOWED BY MEASUREMENT OF THE NRAS EXPRESSION LEVEL IN HUH-7 BY A QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION. AN INCREASE IN THE MESSENGER RNA LEVEL OF THE NRAS GENE WAS DETECTED WHEN HUH-7 WERE TRANSFECTED WITH CORE, NS5A, AND NS2 GENES. OUR FINDINGS SUGGEST THE INVOLVEMENT OF NRAS ONCOGENE IN THE PATHOGENESIS OF HCV3A DERIVED HCC IN PAKISTANI POPULATION AND ALSO IDENTIFIES THE HCV GENES RESPONSIBLE FOR ITS ENHANCED EXPRESSION. OUR STUDY RAISES THE HYPOTHESIS THAT A SINGLE HCV GENE MAY INCREASE THE CHANCES OF MALIGNANCY. THEREFORE, OUR STUDY MAY HAVE IDENTIFIED A USEFUL EPIGENETIC BIOMARKER OF HCC PROGRESSION IN HCV PATIENTS AND MAY HELP TO DEVELOP NOVEL DIAGNOSTIC TOOLS. 2018 18 4056 39 MAPPING THE HETEROGENEITY OF HISTONE MODIFICATIONS ON HEPATITIS B VIRUS DNA USING LIVER NEEDLE BIOPSIES OBTAINED FROM CHRONICALLY INFECTED PATIENTS. COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) FORMS THE BASIS FOR REPLICATION AND PERSISTENCE OF HEPATITIS B VIRUS (HBV) IN THE CHRONICALLY INFECTED LIVER. WE HAVE PREVIOUSLY SHOWN THAT VIRAL TRANSCRIPTION IS SUBJECT TO REGULATION BY POSTTRANSLATIONAL MODIFICATIONS (PTMS) OF HISTONE PROTEINS BOUND TO CCCDNA THROUGH ANALYSIS OF DE NOVO HBV-INFECTED CELL LINES. WE NOW REPORT THE SUCCESSFUL ADAPTATION OF THIS CHROMATIN IMMUNOPRECIPITATION SEQUENCING (CHIPSEQ) APPROACH FOR ANALYSIS OF FINE-NEEDLE PATIENT LIVER BIOPSY SPECIMENS TO INVESTIGATE THE ROLE OF HISTONE PTMS IN CHRONICALLY HBV-INFECTED PATIENTS. USING 18 SPECIMENS FROM PATIENTS IN DIFFERENT STAGES OF CHRONIC HBV INFECTION, OUR WORK SHOWS THAT THE PROFILE OF HISTONE PTMS IN CHRONIC INFECTION IS MORE NUANCED THAN PREVIOUSLY OBSERVED IN IN VITRO MODELS OF ACUTE INFECTION. IN LINE WITH OUR PREVIOUS FINDINGS, WE FIND THAT THE MAJORITY OF HBV-DERIVED SEQUENCES ARE ASSOCIATED WITH THE ACTIVATING HISTONE PTM H3K4ME3. HOWEVER, WE SHOW A STRIKING INTERPATIENT VARIABILITY OF ITS DEPOSITION IN THIS PATIENT COHORT CORRELATED WITH VIRAL TRANSCRIPTION AND PATIENT HBV EARLY ANTIGEN (HBEAG) STATUS. UNEXPECTEDLY, WE DETECTED DEPOSITION OF THE CLASSICAL INHIBITORY HISTONE PTM H3K9ME3 ON HBV-DNA IN AROUND HALF OF THE PATIENT BIOPSY SPECIMENS, WHICH COULD NOT BE LINKED TO REDUCED LEVELS OF VIRAL TRANSCRIPTS. OUR RESULTS SHOW THAT CURRENT IN VITRO MODELS ARE UNABLE TO FULLY RECAPITULATE THE COMPLEX EPIGENETIC LANDSCAPE OF CHRONIC HBV INFECTION OBSERVED IN VIVO AND DEMONSTRATE THAT FINE-NEEDLE LIVER BIOPSY SPECIMENS CAN PROVIDE SUFFICIENT MATERIAL TO FURTHER INVESTIGATE THE INTERACTION OF VIRAL AND HOST PROTEINS ON HBV-DNA.IMPORTANCE HEPATITIS B VIRUS (HBV) IS A MAJOR GLOBAL HEALTH CONCERN, CHRONICALLY INFECTING MILLIONS OF PATIENTS AND CONTRIBUTING TO A RISING BURDEN OF LIVER DISEASE. THE VIRAL GENOME FORMS THE BASIS FOR CHRONIC INFECTION AND HAS BEEN SHOWN TO BE SUBJECT TO REGULATION BY EPIGENETIC MECHANISMS, SUCH AS POSTTRANSLATIONAL MODIFICATION OF HISTONE PROTEINS. HERE, WE CONFIRM AND EXPAND ON PREVIOUS RESULTS BY ADAPTING A HIGH-RESOLUTION TECHNIQUE FOR ANALYSIS OF HISTONE MODIFICATIONS FOR USE WITH PATIENT-DERIVED FINE-NEEDLE LIVER BIOPSY SPECIMENS. OUR WORK HIGHLIGHTS THAT THE SITUATION IN VIVO IS MORE COMPLEX THAN PREDICTED BY CURRENT IN VITRO MODELS, FOR EXAMPLE, BY SUGGESTING A NOVEL, NONCANONICAL ROLE OF THE HISTONE MODIFICATION H3K9ME3 IN THE HBV LIFE CYCLE. IMPORTANTLY, ENABLING THE USE OF FINE-NEEDLE LIVER BIOPSY SPECIMENS FOR SUCH HIGH-RESOLUTION ANALYSES MAY FACILITATE FURTHER RESEARCH INTO THE EPIGENETIC REGULATION OF THE HBV GENOME. 2019 19 6707 29 VIRAL HEPATITIS AND HEPATOCELLULAR CARCINOMA: STATE OF THE ART. VIRAL HEPATITIS IS ONE OF THE MAIN CAUSES LEADING TO HEPATOCELLULAR CARCINOMA (HCC). THE CONTINUED RISE IN INCIDENCE OF HCC SUGGESTS ADDITIONAL FACTORS FOLLOWING INFECTION MAY BE INVOLVED. THIS REVIEW EXAMINES RECENT STUDIES INVESTIGATING THE MOLECULAR MECHANISMS OF CHRONIC HEPATITIS AND ITS ASSOCIATION WITH HEPATOCARCINOGENESIS. HEPATITIS B VIRUS PATIENTS WITH GENOTYPE C DISPLAY AN AGGRESSIVE DISEASE COURSE LEADING TO HCC MORE THAN OTHER GENOTYPES. FURTHERMORE, HEPATITIS B EXCRETORY ANTIGEN (HBEAG) SEEMS TO BE A MORE SENSITIVE PREDICTIVE TUMOR MARKER EXHIBITING A SIX-FOLD HIGHER RELATIVE RISK IN PATIENTS WITH POSITIVE HBSAG AND HBEAG THAN THOSE WITH HBSAG ONLY. SINGLE OR COMBINED MUTATIONS OF VIRAL GENOME CAN PREDICT HCC DEVELOPMENT IN UP TO 80% OF PATIENTS. SEVERAL MUTATIONS IN HBX-GENE ARE RELATED WITH HIGHER HCC INCIDENCE. OVEREXPRESSION OF THE CORE PROTEIN IN HCV LEADS TO HEPATOCELLULAR LIPID ACCUMULATION ASSOCIATED WITH ONCOGENESIS. REDUCED NUMBER AND DECREASED FUNCTIONALITY OF NATURAL KILLER CELLS IN CHRONIC HCV INDIVIDUALS DYSREGULATE THEIR SURVEILLANCE FUNCTION IN TUMOR AND VIRAL CELLS RESULTING IN HCC. FURTHERMORE, HIGH T-CELL IMMUNOGLOBULIN AND MUCIN 3 LEVELS SUPRESS CD8+ T-CELLS, WHICH LEAD TO IMMUNOLOGICAL DYSREGULATION. HEPATITIS D PROMOTES HCC DEVELOPMENT INDIRECTLY VIA MODIFICATIONS TO INNATE IMMUNITY, EPIGENETIC ALTERATIONS AND PRODUCTION OF REACTIVE OXYGEN SPECIES WITH THE LHDAG BEING THE MOST HIGHLY ASSOCIATED WITH HCC DEVELOPMENT. SUMMARIZING THE RESULTS, HBV AND HCV INFECTION REPRESENT THE MOST ASSOCIATED FORMS OF VIRAL HEPATITIS CAUSING HCC. FURTHER STUDIES ARE WARRANTED TO FURTHER IMPROVE THE PREDICTION OF HIGH-RISK PATIENTS AND DEVELOPMENT OF TARGETED THERAPEUTICS PREVENTING THE TRANSITION FROM HEPATIC INFLAMMATION-FIBROSIS TO CANCER. 2021 20 6830 35 [HOW HISTONE DEACETYLASE 3 CONTROLS HEPCIDIN EXPRESSION AND HEPATITIS C VIRUS REPLICATION]. THE KEY ROLE OF HISTONE DEACETYLASES (HDAC) IN THE REGULATION OF THE CELLULAR RESPONSE TO INFECTION WITH THE HEPATITIS C VIRUS (HCV) WAS FIRST DEMONSTRATED IN 2008. WHEN STUDYING THE METABOLISM OF IRON IN THE LIVER TISSUES OF PATIENTS WITH CHRONIC HEPATITIS C, THE AUTHORS FOUND THAT THE EXPRESSION OF THE HEPCIDIN GENE (HAMP), A HORMONE REGULATOR OF IRON EXPORT, IS MARKEDLY REDUCED IN HEPATOCYTES UNDER CONDITIONS OF OXIDATIVE STRESS CAUSED BY VIRAL INFECTION. HDAC WERE INVOLVED IN THE REGULATION OF HEPCIDIN EXPRESSION THROUGH THE CONTROL OF ACETYLATION LEVEL OF HISTONES AND TRANSCRIPTION FACTORS, PRIMARILY STAT3, ASSOCIATED WITH THE HAMP PROMOTER. THE PURPOSE OF THIS REVIEW WAS TO SUMMARIZE CURRENT DATA ON THE FUNCTIONING OF THE HCV-HDAC3-STAT3-HAMP REGULATORY CIRCUIT AS AN EXAMPLE OF A WELL-CHARACTERIZED INTERACTION BETWEEN THE VIRUS AND THE EPIGENETIC APPARATUS OF THE HOST CELL. 2023