1 6882 60 [RESEARCH PROGRESS ON NON-CODING RNAS IN THE MOLECULAR PATHOGENESIS OF HEPATOCELLULAR CARCINOMA]. PRIMARY LIVER CANCER ARISES FROM CHRONIC LIVER DISEASE, AND CIRRHOTIC LIVER GRADUALLY DEVELOPS INTO DYSPLASTIC NODULES THAT EVENTUALLY FORM MALIGNANT TUMORS. IN RECENT YEARS, MOLECULAR BIOTECHNOLOGY DEVELOPMENT HAS DEEPENED PEOPLE'S UNDERSTANDING ON THE PATHOGENESIS OF LIVER CANCER. EPIGENETIC MODIFICATIONS PLAY A SIGNIFICANT ROLE IN DNA METHYLATION, NON-CODING RNAS, CHROMATIN REMODELING, AND HISTONE MODIFICATION. THIS REVIEW FOCUSES ON THE PROGRESS OF CURRENTLY IMPLICATED NON-CODING RNAS IN THE MOLECULAR PATHOGENESIS OF HEPATOCELLULAR CARCINOMA, AND ITS POTENTIAL APPLICATION IN IMPROVING THE DIAGNOSIS AND TREATMENT. 2018 2 2538 27 EPIGENETICS IN HEPATOCELLULAR CARCINOMA: AN UPDATE AND FUTURE THERAPY PERSPECTIVES. HEPATOCELLULAR CARCINOMA (HCC), THE PREDOMINANT FORM OF ADULT LIVER MALIGNANCIES, IS A GLOBAL HEALTH CONCERN. ITS DISMAL PROGNOSIS HAS PROMPTED RECENT SIGNIFICANT ADVANCES IN THE UNDERSTANDING OF ITS ETIOLOGY AND PATHOGENESIS. THE DEREGULATION OF EPIGENETIC MECHANISMS, WHICH MAINTAIN HERITABLE GENE EXPRESSION CHANGES AND CHROMATIN ORGANIZATION, IS IMPLICATED IN THE DEVELOPMENT OF MULTIPLE CANCERS, INCLUDING HCC. THIS REVIEW SUMMARIZES THE CURRENT KNOWLEDGE OF EPIGENETIC MECHANISMS IN THE PATHOGENESIS OF HCC, WITH AN EMPHASIS ON HCC MEDIATED BY CHRONIC HEPATITIS B VIRUS INFECTION. THIS REVIEW ALSO DISCUSSES THE ENCOURAGING OUTCOMES AND LESSONS LEARNT FROM EPIGENETIC THERAPIES FOR HEMATOLOGICAL AND OTHER SOLID CANCERS, AND HIGHLIGHTS THE FUTURE POTENTIAL OF SIMILAR THERAPIES IN THE TREATMENT OF HCC. 2014 3 2014 25 EPIGENETIC BIOMARKERS FOR THE DIAGNOSIS AND TREATMENT OF LIVER DISEASE. RESEARCH IN THE LAST DECADES HAS DEMONSTRATED THE RELEVANCE OF EPIGENETICS IN CONTROLLING GENE EXPRESSION TO MAINTAIN CELL HOMEOSTASIS, AND THE IMPORTANT ROLE PLAYED BY EPIGENOME ALTERATIONS IN DISEASE DEVELOPMENT. MOREOVER, THE REVERSIBILITY OF EPIGENETIC MARKS CAN BE HARNESSED AS A THERAPEUTIC STRATEGY, AND EPIGENETIC MARKS CAN BE USED AS DIAGNOSIS BIOMARKERS. EPIGENETIC ALTERATIONS IN DNA METHYLATION, HISTONE POST-TRANSLATIONAL MODIFICATIONS (PTMS), AND NON-CODING RNA (NCRNA) EXPRESSION HAVE BEEN ASSOCIATED WITH THE PROCESS OF HEPATOCARCINOGENESIS. HERE, WE SUMMARIZE EPIGENETIC ALTERATIONS INVOLVED IN THE PATHOGENESIS OF CHRONIC LIVER DISEASE (CLD), PARTICULARLY FOCUSING ON DNA METHYLATION. WE ALSO DISCUSS THEIR UTILITY AS EPIGENETIC BIOMARKERS IN LIQUID BIOPSY FOR THE DIAGNOSIS AND PROGNOSIS OF HEPATOCELLULAR CARCINOMA (HCC). FINALLY, WE DISCUSS THE POTENTIAL OF EPIGENETIC THERAPEUTIC STRATEGIES FOR HCC TREATMENT. 2021 4 4421 21 MOLECULAR AND FUNCTIONAL GENETICS OF HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE FIFTH MOST COMMON CANCER AND ONE OF THE LEADING CAUSES OF CANCER DEATH WORLDWIDE. HEPATOCARCINOGENESIS IS A MULTISTEP PROCESS DEVELOPING FROM NORMAL THROUGH CHRONIC HEPATITIS/CIRRHOSIS AND DYSPLASTIC NODULES TO HCC. ALTHOUGH WE HAVE INSUFFICIENT UNDERSTANDING TO PROPOSE A ROBUST GENERAL MODEL, WITH ADVANCES IN MOLECULAR METHODS, THERE IS A GROWING UNDERSTANDING OF THE MOLECULAR MECHANISMS IN THE DEVELOPMENT OF HCC. HEPATOCARCINOGENESIS IS STRONGLY LINKED TO INCREASES IN ALLELIC LOSSES, CHROMOSOMAL CHANGES, GENE MUTATIONS, EPIGENETIC ALTERATIONS, AND ALTERATIONS IN MOLECULAR CELLULAR PATHWAYS. SPECIAL EMPHASIS IN THIS REVIEW IS GIVEN TO THE GENETICS, EPIGENETICS, AND REGULATION OF MAJOR SIGNALING PATHWAYS INVOLVED IN HCC SUCH AS WNT/B-CATENIN, RAS, AND PI3K/AKT/MTOR PATHWAYS. A DETAILED UNDERSTANDING OF THE UNDERLYING MOLECULAR MECHANISMS INVOLVED IN THE PROGRESSION OF HCC CAN IMPROVE OUR PREVENTION AND DIAGNOSTIC TOOLS FOR HCC AND BE AN IMPORTANT POTENTIAL SOURCE OF NOVEL MOLECULAR TARGETS FOR NEW THERAPIES. 2010 5 2341 28 EPIGENETIC REGULATION OF LIVER FIBROSIS. FIBROSIS IS A COMMON AND IMPORTANT PATHOLOGY ASSOCIATED WITH PROGRESSIVE CHRONIC LIVER DISEASES AND UNDERLIES THE DEVELOPMENT OF CIRRHOSIS AND HEPATOCELLULAR CARCINOMA. RESEARCH INTO THE MOLECULAR REGULATION OF FIBROSIS HAS DISCOVERED THAT IT IS UNDER THE CONTROL OF A NUMBER OF EPIGENETIC MECHANISMS INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND THE ACTIVITIES OF NON-CODING RNAS. A DEEPER UNDERSTANDING OF HOW EPIGENETIC REGULATORS SUCH AS DNA METHYLTRANSERASES, METHYL-DNA BINDING PROTEINS, HISTONE MODIFYING ENZYMES AND REGULATORY RNA MOLECULES IMPACT ON THE FIBROGENIC PROCESS IS EXPECTED TO RESULT IN NEW BIOMARKERS FOR DISEASE PROGRESSION AS WELL AS NOVEL THERAPEUTIC TARGETS. THE AIM OF THIS MINI-REVIEW IS TO BRIEFLY INTRODUCE THE READER TO THE MAJOR EPIGENETIC REGULATORS SO FAR IDENTIFIED AS BEING IMPLICATED IN FIBROSIS. 2015 6 4476 20 MOLECULAR PATHOGENESIS OF HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE FIFTH MOST COMMON CANCER AND THE THIRD LEADING CAUSE OF CANCER DEATH WORLDWIDE. HEPATOCARCINOGENESIS IS A MULTISTEP PROCESS EVOLVING FROM NORMAL THROUGH CHRONIC HEPATITIS/CIRRHOSIS AND DYSPLASTIC NODULES TO HCC. WITH ADVANCES IN MOLECULAR METHODS, THERE IS A GROWING UNDERSTANDING OF THE MOLECULAR MECHANISMS IN HEPATOCARCINOGENESIS. HEPATOCARCINOGENESIS IS STRONGLY LINKED TO INCREASES IN ALLELIC LOSSES, CHROMOSOMAL CHANGES, GENE MUTATIONS, EPIGENETIC ALTERATIONS AND ALTERATIONS IN MOLECULAR CELLULAR PATHWAYS. SOME OF THESE ALTERATIONS ARE ACCOMPANIED BY A STEPWISE INCREASE IN THE DIFFERENT PATHOLOGICAL DISEASE STAGES IN HEPATOCARCINOGENESIS. OVERALL, A DETAILED UNDERSTANDING OF THE UNDERLYING MOLECULAR MECHANISMS INVOLVED IN THE PROGRESSION OF HCC IS OF FUNDAMENTAL IMPORTANCE TO THE DEVELOPMENT OF EFFECTIVE PREVENTION AND TREATMENT REGIMES FOR HCC. 2008 7 1480 22 DIVERSITY OF DYSREGULATED LONG NON-CODING RNAS IN HBV-RELATED HEPATOCELLULAR CARCINOMA. INFECTION WITH THE HEPATITIS B VIRUS (HBV) CONTINUES TO POSE A MAJOR THREAT TO PUBLIC HEALTH AS APPROXIMATELY 292 MILLION PEOPLE WORLDWIDE ARE CURRENTLY LIVING WITH THE CHRONIC FORM OF THE DISEASE, FOR WHICH TREATMENT IS NON-CURATIVE. CHRONIC HBV INFECTIONS OFTEN PROGRESS TO HEPATOCELLULAR CARCINOMA (HCC) WHICH IS ONE OF THE WORLD'S LEADING CAUSES OF CANCER-RELATED DEATHS. ALTHOUGH THE PROCESS OF HEPATOCARCINOGENESIS IS MULTIFACETED AND HAS YET TO BE FULLY ELUCIDATED, SEVERAL STUDIES HAVE IMPLICATED NUMEROUS LONG NON-CODING RNAS (LNCRNAS) AS CONTRIBUTORS TO THE DEVELOPMENT OF HCC. THESE HOST-DERIVED LNCRNAS, WHICH ARE OFTEN DYSREGULATED AS A CONSEQUENCE OF VIRAL INFECTION, HAVE BEEN SHOWN TO FUNCTION AS SIGNALS, DECOYS, GUIDES, OR SCAFFOLDS, TO MODULATE GENE EXPRESSION AT EPIGENETIC, TRANSCRIPTIONAL, POST-TRANSCRIPTIONAL AND EVEN POST-TRANSLATIONAL LEVELS. THESE LNCRNAS MAINLY FUNCTION TO PROMOTE HBV REPLICATION AND ONCOGENE EXPRESSION OR DOWNREGULATE TUMOR SUPPRESSORS. VERY FEW LNCRNAS ARE KNOWN TO SUPPRESS TUMORIGENESIS AND THESE ARE OFTEN DOWNREGULATED IN HCC. IN THIS REVIEW, WE DESCRIBE THE MECHANISMS BY WHICH LNCRNA DYSREGULATION IN HBV-RELATED HCC PROMOTES TUMORIGENESIS AND CANCER PROGRESSION. 2022 8 3103 20 GENOMIC LANDSCAPE OF HCC. INTRODUCTION: HEPATOCELLULAR CARCINOMA (HCC) IS A LEADING CAUSE OF CANCER RELATED MORTALITY IN THE WORLD AND IT HAS LIMITED TREATMENT OPTIONS. UNDERSTANDING THE MOLECULAR DRIVERS OF HCC IS IMPORTANT TO DEVELOP NOVEL BIOMARKERS AND THERAPEUTICS. PURPOSE OF REVIEW: HCC ARISES IN A COMPLEX BACKGROUND OF CHRONIC HEPATITIS, FIBROSIS AND LIVER REGENERATION WHICH LEAD TO GENOMIC CHANGES. HERE, WE SUMMARIZE STUDIES THAT HAVE EXPANDED OUR UNDERSTANDING OF THE MOLECULAR LANDSCAPE OF HCC. RECENT FINDINGS: RECENT TECHNOLOGICAL ADVANCES IN NEXT GENERATION SEQUENCING (NGS) HAVE ELUCIDATED SPECIFIC GENETIC AND MOLECULAR PROGRAMS INVOLVED IN HEPATOCARCINOGENESIS. WE SUMMARIZE THE MAJOR SOMATIC MUTATIONS AND EPIGENETIC CHANGES HAVE BEEN IDENTIFIED IN NGS-BASED STUDIES. WE ALSO DESCRIBE PROMISING MOLECULAR THERAPIES AND IMMUNOTHERAPIES WHICH TARGET SPECIFIC GENETIC AND EPIGENETIC MOLECULAR EVENTS. SUMMARY: THE GENOMIC LANDSCAPE OF HCC IS INCREDIBLY COMPLEX AND HETEROGENEOUS. PROMISING NEW DEVELOPMENTS ARE HELPING US DECIPHER THE MOLECULAR DRIVERS OF HCC AND LEADING TO NEW THERAPIES. 2020 9 2165 27 EPIGENETIC MECHANISMS IN HEPATITIS B VIRUS-ASSOCIATED HEPATOCELLULAR CARCINOMA. CHRONIC INFECTION OF THE LIVER BY THE HEPATITIS B VIRUS (HBV) IS ASSOCIATED WITH INCREASED RISK FOR DEVELOPING HEPATOCELLULAR CARCINOMA (HCC). A MULTITUDE OF STUDIES HAVE INVESTIGATED THE MECHANISM OF LIVER CANCER PATHOGENESIS DUE TO CHRONIC HBV INFECTION. CHRONIC INFLAMMATION, EXPRESSION OF SPECIFIC VIRAL PROTEINS SUCH AS HBX, THE INTEGRATION SITE OF THE VIRAL GENOME INTO THE HOST GENOME, AND THE VIRAL GENOTYPE, ARE KEY PLAYERS CONTRIBUTING TO HCC PATHOGENESIS. IN ADDITION, THE GENETIC BACKGROUND OF THE HOST AND EXPOSURE TO ENVIRONMENTAL CARCINOGENS ARE ALSO PREDISPOSING PARAMETERS IN HEPATOCARCINOGENESIS. DESPITE THE PLETHORA OF STUDIES, THE MOLECULAR MECHANISM OF HCC PATHOGENESIS REMAINS INCOMPLETELY UNDERSTOOD. IN THIS REVIEW, THE FOCUS IS ON EPIGENETIC MECHANISMS INVOLVED IN THE PATHOGENESIS OF HBV-ASSOCIATED HCC. EPIGENETIC MECHANISMS ARE DYNAMIC MOLECULAR PROCESSES THAT REGULATE GENE EXPRESSION WITHOUT ALTERING THE HOST DNA, ACTING BY MODIFYING THE HOST CHROMATIN STRUCTURE VIA COVALENT POST-TRANSLATIONAL HISTONE MODIFICATIONS, CHANGING THE DNA METHYLATION STATUS, EXPRESSION OF NON-CODING RNAS SUCH AS MICRORNAS AND LONG NONCODING RNAS, AND ALTERING THE SPATIAL, 3-D ORGANIZATION OF THE CHROMATIN OF THE VIRUS-INFECTED CELL. HEREIN, STUDIES ARE DESCRIBED THAT PROVIDE EVIDENCE IN SUPPORT OF DEREGULATION OF EPIGENETIC MECHANISMS IN THE HBV-INFECTED/-REPLICATING HEPATOCYTE AND THEIR CONTRIBUTION TO HEPATOCYTE TRANSFORMATION. IN CONTRAST TO GENETIC MUTATIONS WHICH ARE PERMANENT, EPIGENETIC ALTERATIONS ARE DYNAMIC AND REVERSIBLE. ACCORDINGLY, THE IDENTIFICATION OF ESSENTIAL MOLECULAR EPIGENETIC TARGETS INVOLVED IN HBV-MEDIATED HCC PATHOGENESIS OFFERS THE OPPORTUNITY FOR THE DESIGN AND DEVELOPMENT OF NOVEL EPIGENETIC THERAPEUTIC APPROACHES. 2021 10 3932 17 LIVER REGENERATION, LIVER CANCERS AND CYCLINS. ACCUMULATING EVIDENCE HAS REVEALED THAT MALIGNANT CELL GROWTH IS REGULATED BY COMPLEX MECHANISMS INVOLVED IN GENETIC AND EPIGENETIC FACTORS. AMONG HUMAN CANCERS, CANCER IN THE LIVER (HEPATOCELLULAR CARCINOMA (HCC)) IS CHARACTERIZED BY THE EVIDENCE THAT IT IS USUALLY BASED ON CHRONIC LIVER DISEASES SUCH AS LIVER CIRRHOSIS OR CHRONIC HEPATITIS, IN WHICH THE LIVER IS PERSISTENTLY REGENERATING FOLLOWING HEPATIC INJURY. THIS RAISES THE POSSIBILITY THAT REPEATED HEPATOCYTE PROLIFERATION MAY CAUSE DISORDER OF GENES THAT ARE REGULATING THE CELL CYCLE IN HEPATOCYTES, THUS CAUSING HCC. IN THIS ARTICLE, RECENT STUDIES FOCUSING ON LIVER REGENERATION AND CANCER ARE REVIEWED FROM THE VIEWPOINT OF THE CELL CYCLE THAT IS REGULATED BY CYCLIN AND THE ASSOCIATED PROTEINS. 1998 11 2182 21 EPIGENETIC MECHANISMS REGULATING THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA AND THEIR PROMISE FOR THERAPEUTICS. HEPATOCELLULAR CARCINOMA (HCC) IS ONE OF THE MOST COMMON CANCERS AROUND THE GLOBE AND THIRD MOST FATAL MALIGNANCY. CHRONIC LIVER DISORDERS SUCH AS CHRONIC HEPATITIS AND LIVER CIRRHOSIS OFTEN LEAD TO THE DEVELOPMENT OF HCC. ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS ARE INVOLVED IN THE DEVELOPMENT OF HCC. GENETIC RESEARCH SPARKED BY RECENT DEVELOPMENTS IN NEXT GENERATION SEQUENCING HAS IDENTIFIED THE FREQUENCY OF GENETIC ALTERATIONS THAT OCCUR IN HCC AND HAS LED TO THE IDENTIFICATION OF GENETIC HOTSPOTS. EMERGING EVIDENCE SUGGESTS THAT EPIGENETIC ABERRATIONS ARE STRONGLY ASSOCIATED WITH THE INITIATION AND DEVELOPMENT OF HCC. VARIOUS IMPORTANT GENES ENCODING TUMOR SUPPRESSORS INCLUDING P16, RASSF1A, DLC-1, RUNX3 AND SOCS-1 ARE TARGETS OF EPIGENETIC DYSREGULATION DURING THE DEVELOPMENT OF HCC. THE PRESENT REVIEW DISCUSSES THE IMPORTANCE OF EPIGENETIC REGULATIONS INCLUDING DNA METHYLATION, HISTONE MODIFICATION AND MICRORNA MEDIATED REGULATION OF GENE EXPRESSION DURING TUMORIGENESIS AND THEIR USE AS DISEASE BIOMARKERS. FURTHERMORE, THESE EPIGENETIC ALTERATIONS HAVE BEEN DISCUSSED IN RELATIONSHIP WITH PROMISING THERAPEUTIC PERSPECTIVES FOR HCC AND RELATED CANCERS. 2017 12 3365 29 HISTONE METHYLATION IN PRE-CANCEROUS LIVER DISEASES AND HEPATOCELLULAR CARCINOMA: RECENT OVERVIEW. HEPATOCELLULAR CARCINOMA (HCC) IS THE PREVALENT FORM OF LIVER CANCER IN ADULTS AND THE FOURTH MOST COMMON CAUSE OF CANCER-RELATED DEATH WORLDWIDE. HCC PREDOMINANTLY ARISES IN THE CONTEXT OF CIRRHOSIS AS A RESULT OF CHRONIC LIVER DISEASE, INJURY AND INFLAMMATION. FULL-BLOWN HCC HAS POOR PROGNOSIS BECAUSE IT IS HIGHLY AGGRESSIVE AND RESISTANT TO THERAPY. CONSEQUENTLY, INTERVENTIONS THAT CAN PREVENT OR RESTRAIN HCC EMERGENCE FROM PRE-CANCEROUS DISEASED LIVER ARE A DESIRABLE STRATEGY. HISTONE METHYLATION IS A DYNAMIC, REVERSIBLE EPIGENETIC MODIFICATION INVOLVING THE ADDITION OR REMOVAL OF METHYL GROUPS FROM LYSINE, ARGININE OR GLUTAMINE RESIDUES. ABERRANT ACTIVITY OF HISTONE METHYLATION WRITERS, ERASES AND READERS HAS BEEN IMPLICATED IN SEVERAL CANCER TYPES, INCLUDING HCC. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF RESEARCH ON THE ROLE OF HISTONE METHYLATION IN PRE-CANCEROUS AND CANCEROUS HCC PUBLISHED OVER THE LAST 5 YEARS. IN PARTICULAR, WE PRESENT THE EVIDENCE LINKING ENVIRONMENTAL FACTORS SUCH AS DIET, VIRAL INFECTIONS AND CARCINOGENIC AGENTS WITH DYSREGULATION OF HISTONE METHYLATION DURING LIVER CANCER PROGRESSION WITH THE AIM TO HIGHLIGHT FUTURE THERAPEUTIC POSSIBILITIES. 2023 13 6092 26 THE EFFECTS OF EPIGENETIC MODIFICATION ON THE OCCURRENCE AND PROGRESSION OF LIVER DISEASES AND THE INVOLVED MECHANISM. INTRODUCTION: EPIGENETIC MODIFICATION IS A TYPE OF GENE EXPRESSION AND REGULATION THAT DOES NOT INVOLVE CHANGES IN DNA SEQUENCES. AN INCREASING NUMBER OF STUDIES HAVE PROVEN THAT EPIGENETIC MODIFICATIONS PLAY AN IMPORTANT ROLE IN THE OCCURRENCE AND PROGRESSION OF LIVER DISEASES THROUGH THE GENE REGULATION AND PROTEIN EXPRESSIONS OF HEPATOCELLULAR LIPID METABOLISM, INFLAMMATORY REACTION, CELL PROLIFERATION, AND ACTIVATION, ETC.AREAS COVERED: IN THIS STUDY, WE ELABORATED AND ANALYZED THE UNDERLYING FUNCTIONAL MECHANISM OF EPIGENETIC MODIFICATION IN ALCOHOLIC LIVER DISEASE (ALD), NONALCOHOLIC FATTY LIVER DISEASE (NAFLD), LIVER FIBROSIS (LF), VIRAL HEPATITIS, HEPATOCELLULAR CARCINOMA (HCC), AND RESEARCH PROGRESS OF RECENT YEARS.EXPERT OPINION: THE FURTHER UNDERSTANDING OF EPIGENETIC MECHANISMS THAT CAN REGULATE GENE EXPRESSION AND CELL PHENOTYPE LEADS TO NEW INSIGHTS IN EPIGENETIC CONTROL OF CHRONIC LIVER DISEASE. CURRENTLY, HEPATOLOGISTS ARE EXPLORING THE ROLE OF DNA METHYLATION, HISTONE/CHROMATIN MODIFICATION, AND NON-CODING RNA IN SPECIFIC LIVER PATHOLOGY. THESE FINDINGS HAVE LED TO ADVANCES IN DIRECT EPIGENETIC BIOMARKER TESTING OF PATIENT TISSUE OR BODY FLUID SPECIMENS, AS WELL AS QUANTITATIVE ANALYSIS. BASED ON THESE FINDINGS, DRUG VALIDATION OF SOME TARGETS INVOLVED IN THE EPIGENETIC MECHANISM OF LIVER DISEASE IS GRADUALLY BEING CARRIED OUT CLINICALLY. 2020 14 2970 27 GENETIC AND EPIGENETIC SIGNATURES IN HUMAN HEPATOCELLULAR CARCINOMA: A SYSTEMATIC REVIEW. HEPATOCELLULAR CARCINOMA (HCC) IS THE THIRD MOST COMMON CAUSE OF CANCER DEATHS WORLDWIDE, AND THE INCIDENCE OF THIS FATAL DISEASE IS STILL ON RISE. THE MAJORITY OF HCCS EMERGE IN THE BACKGROUND OF A CHRONIC LIVER DISEASE, SUCH AS CHRONIC HEPATITIS AND LIVER CIRRHOSIS. THE CURRENT UNDERSTANDING IS THAT MAJORITY OF HCCS EVOLVE AS A CONSEQUENCE OF CHRONIC INFLAMMATION AND DUE TO THE PRESENCE OF INFECTION WITH HEPATITIS VIRUSES. THESE UNDERLYING PATHOGENIC STIMULI SUBSEQUENTLY INDUCE A SPECTRUM OF GENETIC AND EPIGENETIC ALTERATIONS IN SEVERAL CANCER-RELATED GENES, WHICH ARE INVOLVED IN CELL-CYCLE REGULATION, CELL GROWTH AND ADHESION. SUCH WIDESPREAD GENOMIC ALTERATIONS CAUSE DISRUPTION OF NORMAL CELLULAR SIGNALING AND FINALLY LEAD TO THE ACQUISITION OF A MALIGNANT PHENOTYPE IN HCC. IN GENERAL, THE TYPE OF GENE ALTERATIONS, SUCH AS POINT MUTATIONS, DELETION OF CHROMOSOMAL REGIONS AND ABNORMAL METHYLATION OF GENE PROMOTERS DIFFER ACCORDING TO THE INDIVIDUAL TARGETED GENE. IN HCC, INCIDENCE OF GENETIC ALTERATIONS IS RELATIVELY RARE AND IS LIMITED TO A SUBSET OF FEW CANCER-SPECIFIC GENES, SUCH AS THE TUMOR SUPPRESSOR P53, RB GENES AND ONCOGENES SUCH AS THE CTNNB1. IN CONTRAST, EPIGENETIC CHANGES THAT INVOLVE ABERRANT METHYLATION OF GENES AND OTHER POST-TRANSCRIPTIONAL HISTONE MODIFICATIONS OCCUR FAR MORE FREQUENTLY, AND SOME OF THESE EPIGENETIC ALTERATIONS ARE NOW BEING EXPLOITED FOR THE DEVELOPMENT OF MOLECULAR DIAGNOSTIC SIGNATURES FOR HCC. IN ADDITION, RECENT FINDINGS OF UNIQUE MICRORNA EXPRESSION PROFILES ALSO PROVIDE AN EVIDENCE FOR THE EXISTENCE OF NOVEL MECHANISMS FOR GENE EXPRESSION REGULATION IN HCC. IN THIS REVIEW ARTICLE, WE WILL REVIEW THE CURRENT STATE OF KNOWLEDGE ON THE ACTIVATION OF VARIOUS ONCOGENIC PATHWAYS AND THE INACTIVATION OF TUMOR SUPPRESSOR PATHWAYS IN HCC THAT RESULT IN THE DISRUPTION OF CANCER-RELATED GENE FUNCTION. IN ADDITION, WE WILL SPECIFICALLY EMPHASIZE THE CLINICAL IMPLICATION OF SOME OF THESE GENETIC AND EPIGENETIC ALTERATIONS IN THE MANAGEMENT OF HEPATOCARCINOGENESIS. 2011 15 2166 28 EPIGENETIC MECHANISMS IN HEPATOCELLULAR CARCINOMA: HOW ENVIRONMENTAL FACTORS INFLUENCE THE EPIGENOME. EPIGENETIC MECHANISMS MAINTAIN HERITABLE CHANGES IN GENE EXPRESSION AND CHROMATIN ORGANIZATION OVER MANY CELL GENERATIONS. IMPORTANTLY, DEREGULATED EPIGENETIC MECHANISMS PLAY A KEY ROLE IN A WIDE RANGE OF HUMAN MALIGNANCIES, INCLUDING LIVER CANCER. HEPATOCELLULAR CARCINOMA (HCC), WHICH ORIGINATES FROM THE HEPATOCYTES, IS BY FAR THE MOST COMMON LIVER CANCER, WITH RATES AND AETIOLOGY THAT SHOW CONSIDERABLE GEOGRAPHIC VARIATION. VARIOUS ENVIRONMENTAL AGENTS AND LIFESTYLES KNOWN TO BE RISK FACTORS FOR HCC (SUCH AS INFECTION BY HEPATITIS B VIRUS (HBV) AND HEPATITIS C VIRUS (HCV), CHRONIC ALCOHOL INTAKE, AND AFLATOXINS) ARE SUSPECTED TO PROMOTE ITS DEVELOPMENT BY ELICITING EPIGENETIC CHANGES, HOWEVER THE PRECISE GENE TARGETS AND UNDERLYING MECHANISMS HAVE NOT BEEN ELUCIDATED. MANY RECENT STUDIES HAVE EXPLOITED CONCEPTUAL AND TECHNOLOGICAL ADVANCES IN EPIGENETICS AND EPIGENOMICS TO INVESTIGATE THE ROLE OF EPIGENETIC EVENTS INDUCED BY ENVIRONMENTAL FACTORS IN HCC TUMORS AND NON-TUMOR PRECANCEROUS (CIRRHOTIC) LESIONS. THESE STUDIES HAVE IDENTIFIED A LARGE NUMBER OF GENES AND PATHWAYS THAT ARE TARGETED BY EPIGENETIC DEREGULATION (CHANGES IN DNA METHYLATION, HISTONE MODIFICATIONS AND RNA-MEDIATED GENE SILENCING) DURING THE DEVELOPMENT AND PROGRESSION OF HCC. FREQUENT IDENTIFICATION OF ABERRANT EPIGENETIC CHANGES IN SPECIFIC GENES IN CIRRHOTIC TISSUE IS CONSISTENT WITH THE NOTION THAT EPIGENETIC DEREGULATION OF SELECTED GENES IN PRE-MALIGNANT LESIONS PRECEDES AND PROMOTES THE DEVELOPMENT OF HCC. IN ADDITION, SEVERAL LINES OF EVIDENCE ARGUE THAT SOME ENVIRONMENTAL FACTORS (SUCH AS HBV VIRUS) MAY ABROGATE CELLULAR DEFENSE SYSTEMS, INDUCE SILENCING OF HOST GENES AND PROMOTE HCC DEVELOPMENT VIA AN "EPIGENETIC STRATEGY". FINALLY, PROFILING STUDIES REVEAL THAT HCC TUMORS AND PRE-CANCEROUS LESIONS MAY EXHIBIT EPIGENETIC SIGNATURES ASSOCIATED WITH SPECIFIC RISK FACTORS AND TUMOR PROGRESSION STAGE. TOGETHER, RECENT EVIDENCE UNDERSCORES THE IMPORTANCE OF ABERRANT EPIGENETIC EVENTS INDUCED BY ENVIRONMENTAL FACTORS IN LIVER CANCER AND HIGHLIGHTS POTENTIAL TARGETS FOR BIOMARKER DISCOVERY AND FUTURE PREVENTIVE AND THERAPEUTIC STRATEGIES. 2011 16 2544 24 EPIGENETICS IN LIVER DISEASE: FROM BIOLOGY TO THERAPEUTICS. KNOWLEDGE OF THE FUNDAMENTAL EPIGENETIC MECHANISMS GOVERNING GENE EXPRESSION AND CELLULAR PHENOTYPE ARE SUFFICIENTLY ADVANCED THAT NOVEL INSIGHTS INTO THE EPIGENETIC CONTROL OF CHRONIC LIVER DISEASE ARE NOW EMERGING. HEPATOLOGISTS ARE IN THE PROCESS OF SHEDDING LIGHT ON THE ROLES PLAYED BY DNA METHYLATION, HISTONE/CHROMATIN MODIFICATIONS AND NON-CODING RNAS IN SPECIFIC LIVER PATHOLOGIES. ALONGSIDE THESE DISCOVERIES ARE ADVANCES IN THE TECHNOLOGIES FOR THE DETECTION AND QUANTIFICATION OF EPIGENETIC BIOMARKERS, EITHER DIRECTLY FROM PATIENT TISSUE OR FROM BODY FLUIDS. THE PREMISE FOR THIS REVIEW IS TO SURVEY THE RECENT ADVANCES IN THE FIELD OF LIVER EPIGENETICS AND TO EXPLORE THEIR POTENTIAL FOR TRANSLATION BY INDUSTRY AND CLINICAL HEPATOLOGISTS FOR THE DESIGN OF NOVEL THERAPEUTICS AND DIAGNOSTIC/PROGNOSTIC BIOMARKERS. IN PARTICULAR, WE PRESENT FINDINGS IN THE CONTEXT OF HEPATOCELLULAR CARCINOMA, FIBROSIS AND NON-ALCOHOLIC FATTY LIVER DISEASE, WHERE THERE IS URGENT UNMET NEED FOR NEW CLINICAL INTERVENTIONS AND BIOMARKERS. 2016 17 3250 19 HEPATITIS B VIRUS INFECTION, MICRORNAS AND LIVER DISEASE. HEPATITIS B VIRUS (HBV) ATTACKS THE LIVER AND CAN CAUSE BOTH ACUTE AS WELL AS CHRONIC LIVER DISEASES WHICH MIGHT LEAD TO LIVER CIRRHOSIS AND HEPATOCELLULAR CARCINOMA. REGARDLESS OF THE AVAILABILITY OF A VACCINE AND NUMEROUS TREATMENT OPTIONS, HBV IS A MAJOR CAUSE OF MORBIDITY AND MORTALITY ACROSS THE WORLD. RECENTLY,MICRORNAS (MIRNAS) HAVE EMERGED AS IMPORTANT MODULATORS OF GENE FUNCTION. STUDIES ON THE ROLE OF MIRNA IN THE REGULATION OF HEPATITIS B VIRUS GENE EXPRESSION HAVE BEEN THE FOCUS OF MODERN ANTIVIRAL RESEARCH. MIRNAS CAN REGULATE VIRAL REPLICATION AND PATHOGENESIS IN A NUMBER OF DIFFERENT WAYS, WHICH INCLUDEFACILITATION, DIRECT OR INDIRECT INHIBITION, ACTIVATION OF IMMUNE RESPONSE, EPIGENETIC MODULATION, ETC. NEVERTHELESS, THESE MECHANISMS CAN APPROPRIATELY BE USED WITH A DIAGNOSTICAND/OR THERAPEUTIC APPROACH. THE PRESENT REVIEW IS AN ATTEMPT TO CLASSIFY SPECIFIC MIRNAS THAT ARE REPORTED TO BE ASSOCIATED WITH VARIOUS ASPECTS OF HEPATITIS B BIOLOGY, IN ORDER TO PRECISELY PRESENT THE PARTICIPATION OF INDIVIDUAL MIRNAS IN MULTIPLE ASPECTS RELATING TO HBV. 2015 18 4687 18 NEW TOOLS FOR MOLECULAR THERAPY OF HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON TYPE OF LIVER CANCER, ARISING FROM NEOPLASTIC TRANSFORMATION OF HEPATOCYTES OR LIVER PRECURSOR/STEM CELLS. HCC IS OFTEN ASSOCIATED WITH PRE-EXISTING CHRONIC LIVER PATHOLOGIES OF DIFFERENT ORIGIN (MAINLY SUBSEQUENT TO HBV AND HCV INFECTIONS), SUCH AS FIBROSIS OR CIRRHOSIS. CURRENT THERAPIES ARE ESSENTIALLY STILL INEFFECTIVE, DUE BOTH TO THE TUMOR HETEROGENEITY AND THE FREQUENT LATE DIAGNOSIS, MAKING NECESSARY THE CREATION OF NEW THERAPEUTIC STRATEGIES TO INHIBIT TUMOR ONSET AND PROGRESSION AND IMPROVE THE SURVIVAL OF PATIENTS. A PROMISING STRATEGY FOR TREATMENT OF HCC IS THE TARGETED MOLECULAR THERAPY BASED ON THE RESTORATION OF TUMOR SUPPRESSOR PROTEINS LOST DURING NEOPLASTIC TRANSFORMATION. IN PARTICULAR, THE DELIVERY OF MASTER GENES OF EPITHELIAL/HEPATOCYTE DIFFERENTIATION, ABLE TO TRIGGER AN EXTENSIVE REPROGRAMMING OF GENE EXPRESSION, COULD ALLOW THE INDUCTION OF AN EFFICIENT ANTITUMOR RESPONSE THROUGH THE SIMULTANEOUS ADJUSTMENT OF MULTIPLE GENETIC/EPIGENETIC ALTERATIONS CONTRIBUTING TO TUMOR DEVELOPMENT. HERE, WE REPORT RECENT LITERATURE DATA SUPPORTING THE USE OF MEMBERS OF THE LIVER ENRICHED TRANSCRIPTION FACTOR (LETF) FAMILY, IN PARTICULAR HNF4ALPHA, AS TOOLS FOR GENE THERAPY OF HCC. 2015 19 4477 20 MOLECULAR PATHOGENESIS OF HUMAN HEPATOCELLULAR CARCINOMA. HEPATOCARCINOGENESIS IS A SLOW PROCESS DURING WHICH GENOMIC CHANGES PROGRESSIVELY ALTER THE HEPATOCELLULAR PHENOTYPE TO PRODUCE CELLULAR INTERMEDIATES THAT EVOLVE INTO HEPATOCELLULAR CARCINOMA. DURING THE LONG PRENEOPLASTIC STAGE, IN WHICH THE LIVER IS OFTEN THE SITE OF CHRONIC HEPATITIS, CIRRHOSIS, OR BOTH, HEPATOCYTE CYCLING IS ACCELERATED BY UPREGULATION OF MITOGENIC PATHWAYS, IN PART THROUGH EPIGENETIC MECHANISMS. THIS LEADS TO THE PRODUCTION OF MONOCLONAL POPULATIONS OF ABERRANT AND DYSPLASTIC HEPATOCYTES THAT HAVE TELOMERE EROSION AND TELOMERASE RE-EXPRESSION, SOMETIMES MICROSATELLITE INSTABILITY, AND OCCASIONALLY STRUCTURAL ABERRATIONS IN GENES AND CHROMOSOMES. DEVELOPMENT OF DYSPLASTIC HEPATOCYTES IN FOCI AND NODULES AND EMERGENCE OF HEPATOCELLULAR CARCINOMA ARE ASSOCIATED WITH THE ACCUMULATION OF IRREVERSIBLE STRUCTURAL ALTERATIONS IN GENES AND CHROMOSOMES, BUT THE GENOMIC BASIS OF THE MALIGNANT PHENOTYPE IS HETEROGENEOUS. THE MALIGNANT HEPATOCYTE PHENOTYPE MAY BE PRODUCED BY THE DISRUPTION OF A NUMBER OF GENES THAT FUNCTION IN DIFFERENT REGULATORY PATHWAYS, PRODUCING SEVERAL MOLECULAR VARIANTS OF HEPATOCELLULAR CARCINOMA. NEW STRATEGIES SHOULD ENABLE THESE VARIANTS TO BE CHARACTERIZED. 2002 20 4335 25 MICRORNAS: SMALL MOLECULES WITH SIGNIFICANT FUNCTIONS, PARTICULARLY IN THE CONTEXT OF VIRAL HEPATITIS B AND C INFECTION. A MICRORNA (MIRNA) IS DEFINED AS A SMALL MOLECULE OF NON-CODING RNA (NCRNA). ITS MOLECULAR SIZE IS ABOUT 20 NUCLEOTIDES (NT), AND IT ACTS ON GENE EXPRESSION'S REGULATION AT THE POST-TRANSCRIPTION LEVEL THROUGH BINDING TO THE 3'UNTRANSLATED REGIONS (UTR), CODING SEQUENCES, OR 5'UTR OF THE TARGET MESSENGER RNAS (MRNAS), WHICH LEADS TO THE SUPPRESSION OR DEGRADATION OF THE MRNA. IN RECENT YEARS, A HUGE EVOLUTION HAS IDENTIFIED THE ORIGIN AND FUNCTION OF MIRNAS, FOCUSING ON THEIR IMPORTANT EFFECTS IN RESEARCH AND CLINICAL APPLICATIONS. FOR EXAMPLE, MICRORNAS ARE KEY PLAYERS IN HCV INFECTION AND HAVE IMPORTANT HOST CELLULAR FACTORS REQUIRED FOR HCV REPLICATION AND CELL GROWTH. ALTERED EXPRESSION OF MIRNAS AFFECTS THE PATHOGENICITY ASSOCIATED WITH HCV INFECTION THROUGH REGULATING DIFFERENT SIGNALING PATHWAYS THAT CONTROL HCV/IMMUNITY INTERACTIONS, PROLIFERATION, AND CELL DEATH. ON THE OTHER HAND, CIRCULATING MIRNAS CAN BE USED AS NOVEL BIOMARKERS AND DIAGNOSTIC TOOLS FOR HCV PATHOGENESIS AND EARLY THERAPEUTIC RESPONSE. MOREOVER, MICRORNAS (MIRNA) HAVE BEEN INVOLVED IN HEPATITIS B VIRUS (HBV) GENE EXPRESSION AND ADVANCED ANTIVIRAL DISCOVERY. THEY REGULATE HBV/HCV REPLICATION AND PATHOGENESIS WITH DIFFERENT PATHWAYS INVOLVING FACILITATION, INHIBITION, ACTIVATION OF THE IMMUNE SYSTEM (INNATE AND ADAPTIVE), AND EPIGENETIC MODIFICATIONS. IN THIS SHORT REVIEW, WE WILL DISCUSS HOW MICRORNAS CAN BE USED AS PROGNOSTIC, DIAGNOSTIC, AND THERAPEUTIC TOOLS, ESPECIALLY FOR CHRONIC HEPATITIS VIRUSES (HBV AND HCV), AS WELL AS HOW THEY COULD BE USED AS NEW BIOMARKERS DURING INFECTION AND ADVANCED TREATMENT. 2023