1 4421 93 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 2 4476 55 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 3 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 4 2970 46 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 5 3103 31 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 6 2182 31 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 7 4687 33 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 8 4477 32 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 9 3932 19 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 10 2166 38 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 11 6798 36 [EPIDEMIOLOGY, RISK FACTORS AND MOLECULAR PATHOGENESIS OF PRIMARY LIVER CANCER]. PRIMARY LIVER CANCER IS THE FIFTH MOST COMMON CANCER WORLDWIDE. HEPATOCELLULAR CARCINOMA ACCOUNTS FOR 85-90% OF PRIMARY LIVER CANCERS. DISTRIBUTION OF HEPATOCELLULAR CARCINOMA SHOWS VARIATIONS AMONG GEOGRAPHIC REGIONS AND ETHNIC GROUPS. MALES HAVE HIGHER LIVER CANCER RATES THAN FEMALES. HEPATOCELLULAR CARCINOMA OCCURS WITHIN AN ESTABLISHED BACKGROUND OF CHRONIC LIVER DISEASE AND CIRRHOSIS (70-90%). MAJOR CAUSES (80%) OF HEPATOCELLULAR CARCINOMA ARE HEPATITIS B, C VIRUS INFECTION, AND AFLATOXIN EXPOSITION. ITS DEVELOPMENT IS A MULTISTEP PROCESS. WE HAVE A GROWING UNDERSTANDING ON THE MOLECULAR PATHOGENESIS. GENETIC AND EPIGENETIC CHANGES ACTIVATE ONCOGENES, INHIBIT TUMORSUPPRESSOR GENES, WHICH RESULT IN AUTONOMOUS CELL PROLIFERATION. THE CHROMOSOMAL INSTABILITY CAUSED BY TELOMERE DYSFUNCTION, THE GROWTH-RETRAINED ENVIRONMENT AND THE ALTERATIONS OF THE MICRO- AND MACROENVIRONMENT HELP THE EXPANSION OF THE MALIGNANT CELLS. UNDERSTANDING THE MOLECULAR MECHANISMS COULD IMPROVE THE SCREENING OF PATIENTS WITH CHRONIC LIVER DISEASE, OR CIRRHOSIS, AND THE PREVENTION AS WELL AS TREATMENT OF HEPATOCELLULAR CARCINOMA. 2008 12 4888 34 OXIDATIVE DAMAGE IN THE PROGRESSION OF CHRONIC LIVER DISEASE TO HEPATOCELLULAR CARCINOMA: AN INTRICATE PATHWAY. THE HISTO-PATHOLOGIC AND MOLECULAR MECHANISMS LEADING TO INITIATION AND PROGRESSION OF HEPATOCELLULAR CARCINOMA (HCC) ARE STILL ILL-DEFINED; HOWEVER, THERE IS INCREASING EVIDENCE THAT THE GRADUAL ACCUMULATION OF MUTATIONS, GENETIC AND EPIGENETIC CHANGES WHICH OCCUR IN PRENEOPLASTIC HEPATOCYTES RESULTS IN THE DEVELOPMENT OF DYSPLASTIC FOCI, NODULES, AND FINALLY, OVERT HCC. AS WELL AS MANY OTHER NEOPLASIAS, LIVER CANCER IS CONSIDERED AN "INFLAMMATORY CANCER", ARISING FROM A CONTEXT OF INFLAMMATION, AND CHARACTERIZED BY INFLAMMATION-RELATED MECHANISMS THAT FAVOR TUMOR CELL SURVIVAL, PROLIFERATION, AND INVASION. MOLECULAR MECHANISMS THAT LINK INFLAMMATION AND NEOPLASIA HAVE BEEN WIDELY INVESTIGATED, AND IT HAS BEEN WELL ESTABLISHED THAT INFLAMMATORY CELLS RECRUITED AT THESE SITES WITH ONGOING INFLAMMATORY ACTIVITY RELEASE CHEMOKINES THAT ENHANCE THE PRODUCTION OF REACTIVE OXYGEN SPECIES. THE LATTER, IN TURN, PROBABLY HAVE A MAJOR PATHOGENIC ROLE IN THE CONTINUUM STARTING FROM HEPATITIS FOLLOWED BY CHRONIC INFLAMMATION, AND ULTIMATELY LEADING TO CANCER. THE RELATIONSHIP AMONGST CHRONIC LIVER INJURY, FREE RADICAL PRODUCTION, AND DEVELOPMENT OF HCC IS EXPLORED IN THE PRESENT REVIEW, PARTICULARLY IN THE LIGHT OF THE COMPLEX NETWORK THAT INVOLVES OXIDATIVE DNA DAMAGE, CYTOKINE SYNTHESIS, TELOMERE DYSFUNCTION, AND MICRORNA REGULATION. 2014 13 5622 33 SEARCH FOR USEFUL BIOMARKERS IN HEPATOCELLULAR CARCINOMA, TUMOR FACTORS AND BACKGROUND LIVER FACTORS (REVIEW). HEPATOCARCINOGENESIS IS A COMPLEX AND MULTISTEP PROCESS THAT INVOLVES THE ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS IN REGULATORY GENES. TO UNDERSTAND THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC), CURRENT RESEARCH HAS UTILIZED IMPROVED ARRAY TECHNOLOGIES. THE IDENTIFICATION OF CANCER-RELATED MOLECULES COULD LEAD TO THE DEVELOPMENT OF NOVEL MOLECULAR TARGETS FOR TREATMENT AND BIOMARKERS FOR PREDICTING PROGNOSIS. HOWEVER, PROGNOSTIC PREDICTION IS INSUFFICIENT WHEN CONSIDERING ONLY TUMOR FACTORS, SINCE HEPATOCARCINOGENESIS IS ALSO GREATLY INFLUENCED BY THE STATUS OF THE BACKGROUND LIVER. CLINICAL BACKGROUND LIVER FACTORS, SUCH AS THE PRESENCE OF CHRONIC ACTIVE HEPATITIS OR CIRRHOSIS, ARE WELL KNOWN AS RISK FACTORS FOR DEVELOPING HCC. IN CONTRAST, GENETIC OR EPIGENETIC BACKGROUND LIVER FACTORS REMAIN UNKNOWN, ALBEIT THOSE ARE IMPORTANT TO UNDERSTAND THE DEVELOPING PROCESS OF HCC. INVESTIGATING BACKGROUND LIVER FACTORS COULD CONTRIBUTE TO THE DEVELOPMENT OF CARCINOGENIC MARKERS OF HCC AND TO THE PREVENTION OF THE DEVELOPMENT OF HCC. IN THE PRESENT STUDY, WE REVIEW THE CURRENTLY IDENTIFIED TUMOR FACTORS AND BACKGROUND LIVER FACTORS FROM A MOLECULAR BIOLOGICAL VIEWPOINT AND ALSO INTRODUCE OUR COMBINATION ARRAY ANALYSIS. 2017 14 3277 31 HEPATOCYTE PLOIDY AND PATHOLOGICAL MUTATIONS IN HEPATOCELLULAR CARCINOMA: IMPACT ON ONCOGENESIS AND THERAPEUTICS. HEPATOCELLULAR CARCINOMA (HCC) OCCURS IN THE CHRONIC LIVER INFLAMMATION SUCH AS VIRAL HEPATITIS, ALCOHOLIC AND NON-ALCOHOLIC STEATOHEPATITIS. WHILE ANTI-VIRAL TREATMENT HAS BEEN SIGNIFICANTLY IMPROVED, THE PREVALENCE OF HCC REMAINS HIGH AND TREATMENT IS STILL CHALLENGING. THE CONTINUATION OF HEPATOCYTE DEATH, INFLAMMATION, AND FIBROSIS LEADS TO THE ACCUMULATION OF GENE ALTERATIONS, WHICH MAY TRIGGER CARCINOGENESIS. HEPATOCYTES ARE A UNIQUE CELL TYPE HAVING MORE THAN ONE COMPLETE SET OF 23 CHROMOSOMES, TERMED POLYPLOIDY. DUE TO GENE REDUNDANCY, HEPATOCYTES MAY TOLERATE LETHAL MUTATIONS. NEXT GENERATION SEQUENCING TECHNOLOGY HAS REVEALED GENE ALTERATIONS IN HCC RELATED TO TELOMERE MAINTENANCE, WNT/BETA-CATENIN PATHWAY, P53 CELL-CYCLE PATHWAY, EPIGENETIC MODIFIERS, OXIDATIVE STRESS PATHWAY, PI3K/AKT/MTOR, AND RAS/RAF/MAPK PATHWAY WITH OR WITHOUT A CHROMOSOMAL INSTABILITY. SOME TYPE OF DRIVER GENE MUTATIONS ACCUMULATES IN HEPATOCYTES AND BREAKS THE ORCHESTRATION OF EXCESSIVE COPIES OF CHROMOSOMES, WHICH MAY LEAD TO UNFAVORABLE GENE EXPRESSIONS AND FUEL TUMORIGENESIS. RECENTLY, MOLECULAR TARGETED DRUGS, DEVELOPED WITH THE AIM OF INTERFERING WITH THESE SIGNALING PATHWAYS, ARE BEING USED FOR HCC PATIENTS IN THE CLINICS. THEREFORE, A DEEPER UNDERSTANDING OF HEPATOCYTE PLOIDY AND GENETIC OR EPIGENETIC ALTERATIONS IS INDISPENSABLE FOR THE ESTABLISHMENT OF NOVEL THERAPEUTIC STRATEGIES AGAINST HCC. 2020 15 5761 41 SOMATIC MUTATIONS, VIRAL INTEGRATION AND EPIGENETIC MODIFICATION IN THE EVOLUTION OF HEPATITIS B VIRUS-INDUCED HEPATOCELLULAR CARCINOMA. LIVER CANCER IN MEN IS THE SECOND LEADING CAUSE OF CANCER DEATH AND HEPATOCELLULAR CARCINOMA (HCC) ACCOUNTS FOR 70%-85% OF THE TOTAL LIVER CANCER WORLDWIDE. CHRONIC INFECTION WITH HEPATITIS B VIRUS (HBV) IS THE MAJOR CAUSE OF HCC. CHRONIC, INTERMITTENTLY ACTIVE INFLAMMATION PROVIDES "FERTILE FIELD" FOR "MUTATION, SELECTION, AND ADAPTATION" OF HBV AND THE INFECTED HEPATOCYTES, A LONG-TERM EVOLUTIONARY PROCESS DURING HBV-INDUCED CARCINOGENESIS. HBV MUTATIONS, WHICH ARE POSITIVELY SELECTED BY INSUFFICIENT IMMUNITY, CAN PROMOTE AND PREDICT THE OCCURRENCE OF HCC. RECENTLY, ADVANCED SEQUENCING TECHNOLOGIES INCLUDING WHOLE GENOME SEQUENCING, EXOME SEQUENCING, AND RNA SEQUENCING PROVIDE OPPORTUNITIES TO BETTER UNDER-STAND THE INSIGHT OF HOW SOMATIC MUTATIONS, STRUCTURE VARIATIONS, HBV INTEGRATIONS, AND EPIGENETIC MODIFICATIONS CONTRIBUTE TO HCC DEVELOPMENT. GENOMIC VARIATIONS OF HCC CAUSED BY VARIOUS ETIOLOGICAL FACTORS MAY BE DIFFERENT, BUT THE COMMON DRIVER MUTATIONS ARE IMPORTANT TO ELUCIDATE THE HCC EVOLUTIONARY PROCESS. GENOME-WIDE ANALYSES OF HBV INTEGRATIONS ARE HELPFUL IN CLARIFYING THE TARGETED GENES OF HBV IN CARCINOGENESIS AND DISEASE PROGRESSION. RNA SEQUENCING CAN IDENTIFY KEY MOLECULES WHOSE EXPRESSIONS ARE EPIGENETICALLY MODIFIED DURING HCC EVOLUTION. IN THIS REVIEW, WE SUMMARIZED THE CURRENT FINDINGS OF NEXT GENERATION SEQUENCINGS FOR HBV-HCC AND PROPOSED A THEORY FRAMEWORK OF CANCER EVOLUTION AND DEVELOPMENT BASED ON THE CURRENT KNOWLEDGE OF HBV-INDUCED HCC TO CHARACTERIZE AND INTERPRET EVOLUTIONARY MECHANISMS OF HCC AND POSSIBLE OTHER CANCERS. UNDERSTANDING THE KEY VIRAL AND GENOMIC VARIATIONS INVOLVED IN HCC EVOLUTION IS ESSENTIAL FOR GENERATING EFFECTIVE DIAGNOSTIC, PROGNOSTIC, AND PREDICTIVE BIOMARKERS AS WELL AS THERAPEUTIC TARGETS FOR THE INTERVENTIONS OF HBV-HCC. 2014 16 309 32 ALCOHOL AND HEPATOCELLULAR CARCINOMA: ADDING FUEL TO THE FLAME. PRIMARY TUMORS OF THE LIVER REPRESENT THE FIFTH MOST COMMON TYPE OF CANCER IN THE WORLD AND THE THIRD LEADING CAUSE OF CANCER-RELATED DEATH. CASE-CONTROL STUDIES FROM DIFFERENT COUNTRIES REPORT THAT CHRONIC ETHANOL CONSUMPTION IS ASSOCIATED WITH AN APPROXIMATELY 2-FOLD INCREASED ODDS RATIO FOR HEPATOCELLULAR CARCINOMA (HCC). DESPITE THE SUBSTANTIAL EPIDEMIOLOGIC DATA IN HUMANS DEMONSTRATING THAT CHRONIC ALCOHOL CONSUMPTION IS A MAJOR RISK FACTOR FOR HCC DEVELOPMENT, THE PATHWAYS CAUSING ALCOHOL-INDUCED LIVER CANCER ARE POORLY UNDERSTOOD. IN THIS OVERVIEW, WE SUMMARIZE THE EPIDEMIOLOGICAL EVIDENCE FOR THE ASSOCIATION BETWEEN ALCOHOL AND LIVER CANCER, REVIEW THE GENETIC, ONCOGENIC, AND EPIGENETIC FACTORS THAT DRIVE HCC DEVELOPMENT SYNERGISTICALLY WITH ETHANOL INTAKE AND DISCUSS THE ESSENTIAL MOLECULAR AND METABOLIC PATHWAYS INVOLVED IN ALCOHOL-INDUCED LIVER TUMORIGENESIS. 2017 17 915 37 CHRONIC HEPATITIS B VIRUS AND HEPATITIS C VIRUS INFECTIONS AND CANCER: SYNERGY BETWEEN VIRAL AND HOST FACTORS. HEPATITIS B VIRUS (HBV) OR HEPATITIS C VIRUS (HCV) INFECTIONS REPRESENT MAJOR CAUSES OF CHRONIC LIVER DISEASE AND HEPATOCELLULAR CARCINOMA. DESPITE INDUCING SHARED PATHOLOGICAL EVENTS LEADING TO ONCOGENIC TRANSFORMATION, THESE TWO VIRUSES PRESENT PROFOUND DIFFERENCES IN THEIR MOLECULAR FEATURES, LIFE CYCLE AND INTERPLAY WITH HOST FACTORS, WHICH SIGNIFICANTLY DIFFERENTIATE THE PROGNOSTIC AND THERAPEUTIC APPROACH TO THE RELATED DISEASES. IN THE PRESENT REVIEW, WE REPORT THE MAIN MECHANISMS INVOLVED IN THE MULTISTEP PROCESS LEADING FROM HCV/HBV INFECTION AND CANCER DEVELOPMENT, DISCUSSING SIDE-BY-SIDE THE ANALOGIES AND DIFFERENCES BETWEEN THE TWO VIRUSES. SUCH EVENTS CAN BE BROADLY CATEGORIZED INTO (A) DIRECT ONCOGENIC EFFECTS, INVOLVING INTEGRATION IN THE HOST GENOME (IN THE CASE OF HBV) AND CHROMOSOMAL INSTABILITY, INTERFERENCE WITH ONCOSUPPRESSOR PATHWAYS, INDUCTION OF OXIDATIVE STRESS, PROMOTION OF ANGIOGENESIS, EPITHELIAL-MESENCHYMAL TRANSITION, ALTERATIONS IN THE EPIGENETIC ASSET AND INTERACTION WITH NON-CODING RNAS; AND (B) INDIRECT ACTIVITIES MOSTLY MEDIATED BY HOST EVENTS, INCLUDING CHRONIC INFLAMMATION SUSTAINED BY PECULIAR CYTOKINE NETWORKS (SUCH AS INTERLEUKIN-6 AND LYMPHOTOXINS), METABOLIC DYSFUNCTIONS PROMOTED BY STEATOHEPATITIS, INTERPLAY WITH GUT MICROBIOTA AND FIBROTIC EVENTS (MAINLY IN HCV INFECTION). THIS SCENARIO SUGGESTS THAT THE INTEGRATED STUDY OF VIRAL AND HOST FACTORS MAY LEAD TO THE SUCCESSFUL DEVELOPMENT OF NOVEL BIOMARKERS AND TARGETS FOR THERAPY. 2015 18 3265 39 HEPATOCARCINOMA: GENETIC AND EPIGENETIC FEATURES. HCC IS THE THIRD LEADING CAUSE OF CANCER-RELATED DEATHS WORLDWIDE, ACCOUNTING FOR ABOUT 1 MILLION DEATHS ANNUALLY. THE INCIDENCE OF HCC IS HIGHEST IN ASIA AND AFRICA, WHERE THE ENDEMIC HIGH PREVALENCE OF HEPATITIS B AND HEPATITIS C STRONGLY PREDISPOSES TO THE DEVELOPMENT OF CHRONIC LIVER DISEASE AND SUBSEQUENT DEVELOPMENT OF HCC. PATIENTS WITH HCC GENERALLY PRESENT AT AN ADVANCED STAGE DUE TO COMPENSATED CIRRHOSIS DEFINED BY THE ABSENCE OF PATHOGNOMONIC SYMPTOMS, RESULTING IN DEATH WITHIN 6 TO 20 MONTHS, SUGGESTING AN URGENT NEED IN TREATMENT MODALITIES THAT WILL DRAMATICALLY DECREASE THE MORTALITY RATE OF HCC. THE MOLECULAR HEPATOCARCINOGENESIS IS, HOWEVER, A GRADUAL PROCESS DURING WHICH GENETIC ALTERATIONS PROGRESSIVELY ACCUMULATE AND LEAD TO HCC THROUGH INTERMEDIATE PRENEOPLASTIC STAGES. WITH THE ADVENT OF WHOLE GENOME SEQUENCING TOOLS, VARIOUS MUTATIONS ASSOCIATED WITH HCC HAVE BEEN IDENTI FI ED, WHICH HAVE ADVANCED OUR MOLECULAR UNDERSTANDING OF HCC. HOWEVER, THE FREQUENCY OF THESE MUTATIONS IS RARE, AND THESE GENETIC MUTATIONS ONLY PARTLY EXPLAIN THE ETIOLOGY OF THE DISEASE. BETTER UNDERSTANDING AND CHARACTERIZATION OF NOVEL GENETIC AND EPIGENETIC ALTERATIONS, WHICH ARE IMPORTANT TO HEPATOCARCINOGENESIS, MAY HELP UNDERSTAND THE MOLECULAR PATHOGENESIS OF HCC, AS WELL AS PROVIDING NOVEL THERAPEUTIC TARGETS FOR HCC TREATMENT. FURTHER CONSIDERATION SHOULD BE GIVEN TO DEVELOPING MORE EFFECTIVE MOLECULAR DIAGNOSTIC MARKERS AND TARGETED DRUG THERAPY. 2018 19 3263 36 HEPATITIS VIRUS AND HEPATOCELLULAR CARCINOMA: RECENT ADVANCES. HEPATOCELLULAR CARCINOMA (HCC) REMAINS A GLOBAL HEALTH CHALLENGE, CAUSING 600,000 DEATHS EACH YEAR. INFECTIOUS FACTORS, INCLUDING HEPATITIS B VIRUS (HBV), HEPATITIS C VIRUS (HCV) AND HEPATITIS D VIRUS (HDV), HAVE LONG BEEN CONSIDERED THE MAJOR RISK FACTORS FOR THE DEVELOPMENT AND PROGRESSION OF HCC. THESE PATHOGENS INDUCE HEPATOCYTE TRANSFORMATION THROUGH A VARIETY OF MECHANISMS, INCLUDING INSERTIONAL MUTATIONS CAUSED BY VIRAL GENE INTEGRATION, EPIGENETIC CHANGES, AND THE INDUCTION OF LONG-TERM IMMUNE DYSFUNCTION. THE DISCOVERY OF THESE MECHANISMS, WHILE ADVANCING OUR UNDERSTANDING OF THE DISEASE, ALSO PROVIDES TARGETS FOR NEW DIAGNOSTIC AND THERAPEUTIC APPROACHES. IN ADDITION, THE DISCOVERY AND RESEARCH OF CHRONIC HEV INFECTION OVER THE PAST DECADE INDICATE THAT THIS COMMON HEPATITIS VIRUS ALSO SEEMS TO HAVE THE POTENTIAL TO INDUCE HCC. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF RECENT STUDIES ON THE LINK BETWEEN HEPATITIS VIRUS AND HCC, AS WELL AS NEW DIAGNOSTIC AND THERAPEUTIC APPROACHES TO HCC BASED ON THESE FINDINGS. FINALLY, WE ALSO DISCUSS THE POTENTIAL RELATIONSHIP BETWEEN HEV AND HCC. IN CONCLUSION, THESE ASSOCIATIONS WILL FURTHER OPTIMIZE THE DIAGNOSIS AND TREATMENT OF INFECTION-ASSOCIATED HCC AND CALL FOR BETTER MANAGEMENT POLICIES. 2023 20 4134 38 MECHANISMS OF HUMAN HEPATOCARCINOGENESIS. THE MAJOR RISK FACTORS AND ETIOLOGICAL AGENTS RESPONSIBLE FOR DEVELOPMENT OF HEPATOCELLULAR CARCINOMA IN HUMANS HAVE BEEN IDENTIFIED AND CHARACTERIZED. AMONG THESE ARE CHRONIC INFECTION WITH HEPATITIS B VIRUS OR HEPATITIS C VIRUS, EXPOSURE TO AFLATOXIN B1, AND CIRRHOSIS OF ANY ETIOLOGY (INCLUDING ALCOHOLIC CIRRHOSIS AND CIRRHOSIS ASSOCIATED WITH GENETIC LIVER DISEASES). BOTH CHRONIC HEPATITIS AND CIRRHOSIS REPRESENT MAJOR PRENEOPLASTIC CONDITIONS OF THE LIVER AS THE MAJORITY OF HEPATOCELLULAR CARCINOMAS ARISE IN THESE PATHOLOGICAL SETTINGS. HEPATOCARCINOGENESIS REPRESENTS A LINEAR AND PROGRESSIVE PROCESS IN WHICH SUCCESSIVELY MORE ABERRANT MONOCLONAL POPULATIONS OF HEPATOCYTES EVOLVE. REGENERATIVE HEPATOCYTES IN FOCAL LESIONS IN THE INFLAMED LIVER (CHRONIC HEPATITIS OR CIRRHOSIS) GIVE RISE TO HYPERPLASTIC HEPATOCYTE NODULES, AND THESE PROGRESS TO DYSPLASTIC NODULES, WHICH ARE THOUGHT TO BE THE DIRECT PRECURSOR OF HEPATOCELLULAR CARCINOMA. IN MOST CASES, THE NEOPLASTIC TRANSFORMATION OF HEPATOCYTES RESULTS FROM ACCUMULATION OF GENETIC DAMAGE DURING THE REPETITIVE CELLULAR PROLIFERATION THAT OCCURS IN THE INJURED LIVER IN RESPONSE TO PARACRINE GROWTH FACTOR AND CYTOKINE STIMULATION. HEPATOCELLULAR CARCINOMAS EXHIBIT NUMEROUS GENETIC ABNORMALITIES (INCLUDING CHROMOSOMAL DELETIONS, REARRANGEMENTS, ANEUPLOIDY, GENE AMPLIFICATIONS, AND MUTATIONS), AS WELL AS EPIGENETIC ALTERATIONS (INCLUDING MODULATION OF DNA METHYLATION). THESE GENETIC AND EPIGENETIC ALTERATIONS COMBINE TO ACTIVATE POSITIVE MEDIATORS OF CELLULAR PROLIFERATION (INCLUDING CELLULAR PROTO-ONCOGENES AND THEIR MITOGENIC SIGNALING PATHWAYS) AND INACTIVATE NEGATIVE MEDIATORS OF CELLULAR PROLIFERATION (INCLUDING TUMOR SUPPRESSOR GENES), RESULTING IN CELLS WITH AUTONOMOUS GROWTH POTENTIAL. HOWEVER, HEPATOCELLULAR CARCINOMAS EXHIBIT A HIGH DEGREE OF GENETIC HETEROGENEITY, SUGGESTING THAT MULTIPLE MOLECULAR PATHWAYS MAY BE INVOLVED IN THE GENESIS OF SUBSETS OF HEPATOCELLULAR NEOPLASMS. CONTINUED INVESTIGATION OF THE MECHANISMS OF HEPATOCARCINOGENESIS WILL REFINE OUR CURRENT UNDERSTANDING OF THE MOLECULAR AND CELLULAR BASIS FOR NEOPLASTIC TRANSFORMATION IN LIVER, ENABLING THE DEVELOPMENT OF EFFECTIVE STRATEGIES FOR PREVENTION AND/OR MORE EFFECTIVE TREATMENT OF HEPATOCELLULAR CARCINOMA. 2003