1 4454 91 MOLECULAR MECHANISMS DRIVING PROGRESSION OF LIVER CIRRHOSIS TOWARDS HEPATOCELLULAR CARCINOMA IN CHRONIC HEPATITIS B AND C INFECTIONS: A REVIEW. ALMOST ALL PATIENTS WITH HEPATOCELLULAR CARCINOMA (HCC), A MAJOR TYPE OF PRIMARY LIVER CANCER, ALSO HAVE LIVER CIRRHOSIS, THE SEVERITY OF WHICH HAMPERS EFFECTIVE TREATMENT FOR HCC DESPITE RECENT PROGRESS IN THE EFFICACY OF ANTICANCER DRUGS FOR ADVANCED STAGES OF HCC. HERE, WE REVIEW RECENT KNOWLEDGE CONCERNING THE MOLECULAR MECHANISMS OF LIVER CIRRHOSIS AND ITS PROGRESSION TO HCC FROM GENETIC AND EPIGENOMIC POINTS OF VIEW. BECAUSE ~70% OF PATIENTS WITH HCC HAVE HEPATITIS B VIRUS (HBV) AND/OR HEPATITIS C VIRUS (HCV) INFECTION, WE FOCUSED ON HBV- AND HCV-ASSOCIATED HCC. THE LITERATURE SUGGESTS THAT GENETIC AND EPIGENETIC FACTORS, SUCH AS MICRORNAS, PLAY A ROLE IN LIVER CIRRHOSIS AND ITS PROGRESSION TO HCC, AND THAT HBV- AND HCV-ENCODED PROTEINS APPEAR TO BE INVOLVED IN HEPATOCARCINOGENESIS. FURTHER STUDIES ARE NEEDED TO ELUCIDATE THE MECHANISMS, INCLUDING IMMUNE CHECKPOINTS AND MOLECULAR TARGETS OF KINASE INHIBITORS, ASSOCIATED WITH LIVER CIRRHOSIS AND ITS PROGRESSION TO HCC. 2019 2 2980 34 GENETIC BASIS OF HEPATITIS VIRUS-ASSOCIATED HEPATOCELLULAR CARCINOMA: LINKAGE BETWEEN INFECTION, INFLAMMATION, AND TUMORIGENESIS. HEPATITIS VIRUS INFECTION IS A LEADING CAUSE OF CHRONIC LIVER DISEASE, INCLUDING CIRRHOSIS AND HEPATOCELLULAR CARCINOMA (HCC). ALTHOUGH ANTI-VIRAL THERAPIES AGAINST HEPATITIS B VIRUS (HBV) AND HEPATITIS C VIRUS (HCV) HAVE DRAMATICALLY PROGRESSED DURING THE PAST DECADE, THE ESTIMATED NUMBER OF PEOPLE CHRONICALLY INFECTED WITH HBV AND/OR HCV IS ~370 MILLION, AND HEPATITIS VIRUS-ASSOCIATED HEPATOCARCINOGENESIS IS A SERIOUS HEALTH CONCERN WORLDWIDE. UNDERSTANDING THE MECHANISM OF VIRUS-ASSOCIATED CARCINOGENESIS IS CRUCIAL TOWARD BOTH TREATMENT AND PREVENTION, AND THE RECENTLY DEVELOPED WHOLE GENOME/EXOME SEQUENCING ANALYSIS USING NEXT-GENERATION SEQUENCING TECHNOLOGIES HAS CONTRIBUTED TO UNVEILING THE LANDSCAPE OF GENETIC AND EPIGENETIC ABERRATIONS IN NOT ONLY TUMOR TISSUES BUT ALSO THE BACKGROUND LIVER TISSUES UNDERLYING CHRONIC LIVER DAMAGE CAUSED BY HEPATITIS VIRUS INFECTION. SEVERAL MAJOR MECHANISMS UNDERLIE THE GENETIC AND EPIGENETIC ABERRATIONS IN THE HEPATITIS VIRUS-INFECTED LIVER, SUCH AS THE GENERATION OF REACTIVE OXIDATIVE STRESS, ECTOPIC EXPRESSION OF DNA MUTATOR ENZYMES, AND DYSFUNCTION OF THE DNA REPAIR SYSTEM. IN ADDITION, DIRECT ONCOGENIC EFFECTS OF HEPATITIS VIRUS, REPRESENTED BY THE INTEGRATION OF HBV-DNA, ARE OBSERVED IN INFECTED HEPATOCYTES. ELUCIDATING THE WHOLE PICTURE OF GENETIC AND EPIGENETIC ALTERATIONS, AS WELL AS THE MECHANISMS OF TUMORIGENESIS, WILL FACILITATE THE DEVELOPMENT OF EFFICIENT TREATMENT AND PREVENTION STRATEGIES FOR HEPATITIS VIRUS-ASSOCIATED HCC. 2017 3 3394 32 HOST EPIGENETIC ALTERATIONS AND HEPATITIS B VIRUS-ASSOCIATED HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST FREQUENT PRIMARY MALIGNANCY OF THE LIVER AND A LEADING CAUSE OF CANCER-RELATED DEATHS WORLDWIDE. ALTHOUGH MUCH PROGRESS HAS BEEN MADE IN HCC DRUG DEVELOPMENT IN RECENT YEARS, TREATMENT OPTIONS REMAIN LIMITED. THE MAJOR CAUSE OF HCC IS CHRONIC HEPATITIS B VIRUS (HBV) INFECTION. DESPITE THE EXISTENCE OF A VACCINE, MORE THAN 250 MILLION INDIVIDUALS ARE CHRONICALLY INFECTED BY HBV. CURRENT ANTIVIRAL THERAPIES CAN REPRESS VIRAL REPLICATION BUT TO DATE THERE IS NO CURE FOR CHRONIC HEPATITIS B. OF NOTE, INHIBITION OF VIRAL REPLICATION REDUCES BUT DOES NOT ELIMINATE THE RISK OF HCC DEVELOPMENT. HBV CONTRIBUTES TO LIVER CARCINOGENESIS BY DIRECT AND INDIRECT EFFECTS. THIS REVIEW SUMMARIZES THE CURRENT KNOWLEDGE OF HBV-INDUCED HOST EPIGENETIC ALTERATIONS AND THEIR ASSOCIATION WITH HCC, WITH AN EMPHASIS ON THE INTERACTIONS BETWEEN HBV PROTEINS AND THE HOST CELL EPIGENETIC MACHINERY LEADING TO MODULATION OF GENE EXPRESSION. 2021 4 3187 37 HBV INDUCED HEPATOCELLULAR CARCINOMA AND RELATED POTENTIAL IMMUNOTHERAPY. CHRONIC INFECTION OF HEPATITIS B VIRUS (HBV) HAS LONG BEEN RECOGNIZED AS A MAJOR RISK FACTOR IN THE INITIATION AND DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC), CONTRIBUTING TO OVER HALF THE CASES OF HCC WORLDWIDE. TRANSFORMATION OF THE LIVER WITH HBV INFECTION TO HCC MAINLY RESULTS FROM LONG-TERM INTERACTION BETWEEN HBV AND THE HOST HEPATOCYTES VIA A VARIETY OF MECHANISMS, INCLUDING HBV DNA INTEGRATION, PROLONGED EXPRESSION OF THE VIRAL HBX REGULATORY PROTEIN AND/OR ABERRANT PRES/S ENVELOPE PROTEINS, AND EPIGENETIC DYSREGULATION OF TUMOR SUPPRESSOR GENES. WHILE THERE HAVE BEEN SEVERAL FAILURES IN THE DEVELOPMENT OF DRUGS FOR HCC, THE IMMUNE-TOLERANT MICROENVIRONMENT OF THIS MALIGNANCY SUGGESTS THAT IMMUNOTHERAPEUTIC AGENTS COULD PROVIDE BENEFITS FOR THESE PATIENTS. THIS IS SUPPORTED BY RECENT DATA SHOWING THAT IMMUNOTHERAPY HAS PROMISING ACTIVITY IN PATIENTS WITH ADVANCED HCC. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF HBV-INDUCED HCC AND RECENT IMMUNE BASED APPROACHES FOR THE TREATMENT OF HCC PATIENTS. 2020 5 2939 29 GENETIC AND EPIGENETIC ALTERATIONS IN HEPATITIS B VIRUS-ASSOCIATED HEPATOCELLULAR CARCINOMA. HEPATITIS B VIRUS (HBV) IS A MAJOR CAUSE OF HEPATOCELLULAR CARCINOMA (HCC). ITS CHRONIC INFECTION CAN LEAD TO CHRONIC LIVER INFLAMMATION AND THE ACCUMULATION OF GENETIC ALTERATIONS TO RESULT IN THE ONCOGENIC TRANSFORMATION OF HEPATOCYTES. HBV CAN ALSO SENSITIZE HEPATOCYTES TO ONCOGENIC TRANSFORMATION BY CAUSING GENETIC AND EPIGENETIC CHANGES OF THE HOST CHROMOSOMES. HBV DNA CAN INSERT INTO HOST CHROMOSOMES AND RECENT LARGE-SCALE WHOLE-GENOME SEQUENCING STUDIES REVEALED RECURRENT HBV DNA INTEGRATIONS SITES THAT MAY PLAY IMPORTANT ROLES IN THE INITIATION OF HEPATOCELLULAR CARCINOGENESIS. HBV CAN ALSO CAUSE EPIGENETIC CHANGES BY ALTERING THE METHYLATION STATUS OF CELLULAR DNA, THE POST-TRANSLATIONAL MODIFICATION OF HISTONES, AND THE EXPRESSION OF MICRORNAS. THESE CHANGES CAN ALSO LEAD TO THE EVENTUAL HEPATOCELLULAR TRANSFORMATION. THESE RECENT FINDINGS ON THE GENETIC AND EPIGENETIC ALTERATIONS OF THE HOST CHROMOSOMES INDUCED BY HBV OPENED A NEW AVENUE FOR THE DEVELOPMENT OF NOVEL DIAGNOSIS AND TREATMENTS FOR HBV-INDUCED HCC. 2015 6 3263 39 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 7 6797 36 [EPIDEMIOLOGY, NATURAL HISTORY AND PATHOGENESIS OF HEPATOCELLULAR CARCINOMA]. HEPATOCELLULAR CARCINOMA (HCC) IS THE MAIN TYPE OF PRIMARY LIVER CANCERS AND THE THIRD MOST COMMON CAUSE OF CANCER MORTALITY WORLDWIDE. IN FRANCE, RISING NUMBER BETWEEN 5000 AND 6000 CASES ARE DIAGNOSED EACH YEAR. THE MAJOR RISK FACTOR FOR HEPATOCELLULAR CARCINOMA IS CHRONIC HEPATITIS: VIRAL HEPATITIS B, VIRAL HEPATITIS C, CONSUMPTION OF ALCOHOL, HEMOCHROMATOSIS. HEPATOCELLULAR CARCINOMA IS CLOSELY ASSOCIATED TO LIVER CIRRHOSIS, WHICH IS A TRUE PRECANCEROUS STATE. BECAUSE HEPATOCARCINOGENESIS IS A LONG AND HETEROGENEOUS PROCESS, THERE IS STILL MUCH TO UNDERSTAND. MANY GENETIC AND EPIGENETIC ALTERATIONS ARE DESCRIBED LEADING TO CHANGES IN CELLULAR SIGNALLING CASCADES INVOLVED IN REGULATION OF GROWTH, DIFFERENTIATION, APOPTOSIS, MOTILITY. HEPATITIS VIRUSES PLAY A DIRECT ONCOGENIC ROLE THROUGH THE INTERACTION BETWEEN VIRAL AND CELLULAR PROTEINS, WHICH CONTROL CELL HOMEOSTASIS, OR BY THE INTEGRATION OF HEPATITIS B VIRUS GENOME INTO THE HOST GENOME. FURTHERMORE, HEPATITIS VIRUSES PLAY AN INDIRECT ONCOGENIC ROLE BY CAUSING CHRONIC INFLAMMATION AND HEPATOCYTE REGENERATION RELATED TO VIRAL HEPATOPATHY. IN EXPECTATION OF A BETTER UNDERSTANDING OF HEPATOCARCINOGENESIS AND NEW TREATMENTS, PREVENTION FROM RISK FACTORS AND ULTRASONOGRAPHIC SCREENING OF PATIENTS WITH CIRRHOSIS SHOULD INCREASE PROGNOSIS. 2011 8 4133 28 MECHANISMS OF HEPATITIS B VIRUS-INDUCED HEPATOCARCINOGENESIS. HEPATITIS B VIRUS (HBV) IS A MAJOR CAUSE OF HEPATOCELLULAR CARCINOMA (HCC). THERE ARE APPROXIMATELY 250 MILLION PEOPLE IN THE WORLD THAT ARE CHRONICALLY INFECTED BY THIS VIRUS, RESULTING IN NEARLY 1 MILLION DEATHS EVERY YEAR. MANY OF THESE PATIENTS DIE FROM SEVERE LIVER DISEASES, INCLUDING HCC. HBV MAY INDUCE HCC THROUGH THE INDUCTION OF CHRONIC LIVER INFLAMMATION, WHICH CAN CAUSE OXIDATIVE STRESS AND DNA DAMAGE. HOWEVER, MANY STUDIES ALSO INDICATED THAT HBV COULD INDUCE HCC VIA THE ALTERATION OF HEPATOCELLULAR PHYSIOLOGY THAT MAY INVOLVE GENETIC AND EPIGENETIC CHANGES OF THE HOST DNA, THE ALTERATION OF CELLULAR SIGNALING PATHWAYS, AND THE INHIBITION OF DNA REPAIR MECHANISMS. THIS ALTERATION OF CELLULAR PHYSIOLOGY CAN LEAD TO THE ACCUMULATION OF DNA DAMAGES AND THE PROMOTION OF CELL CYCLES AND PREDISPOSE HEPATOCYTES TO ONCOGENIC TRANSFORMATION. 2021 9 5761 39 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 10 6850 33 [MOLECULAR PATHOGENESIS OF HEPATOCELLULAR CARCINOMA]. HEPATOCELLULAR CARCINOMA (HCC) IS THE THIRD LEADING CAUSE OF CANCER DEATH WORLDWIDE. HCC NEARLY ALMOST ALWAYS DEVELOPS IN CONNECTION WITH CHRONIC HEPATITIS OR LIVER CIRRHOSIS, MAINLY DUE TO HEPATITIS B VIRUS OR HEPATITIS C VIRUS INFECTION. SEVERAL FACTORS ARE SUPPOSED TO PLAY KEY ROLES IN THE DEVELOPMENT OF HCC, SUCH AS ABERRANT VIRAL PROTEIN EXPRESSION, GENOMIC INSTABILITY WITH/WITHOUT INSERTIONS OF VIRAL DNAS, GENE MUTATIONS, EPIGENETIC GENE MODIFICATION, OXIDATIVE STRESS, AND ALTERATION OF THE MICROENVIRONMENT INCLUDING INFLAMMATION, FIBROSIS, AND EMERGENCE OF STEM/PROGENITOR CELLS AS A RESULT OF REPEATED NECROSIS AND REGENERATION OF HEPATOCYTES. THE ELUCIDATION OF MOLECULAR MECHANISMS OF HEPATOCARCINOGENESIS HAS SUCCESSFULLY PROVIDED SMALL MOLECULE INHIBITORS TARGETING ABERRANTLY ACTIVATED SIGNALING IN HCC. DEVELOPMENT OF NOVEL CLASSIFICATION SYSTEMS BASED ON THE MOLECULAR PROFILES AND DRUG SENSITIVITIES AGAINST MOLECULARLY TARGETED COMPOUNDS IS CURRENTLY UNDERWAY TO FACILITATE NOVEL STRATEGIES FOR EFFECTIVE ERADICATION OF HCC. 2010 11 3259 34 HEPATITIS C VIRUS AND HEPATOCELLULAR CARCINOMA: WHEN THE HOST LOSES ITS GRIP. CHRONIC INFECTION WITH HEPATITIS C VIRUS (HCV) IS A MAJOR CAUSE OF HEPATOCELLULAR CARCINOMA (HCC). NOVEL TREATMENTS WITH DIRECT-ACTING ANTIVIRALS ACHIEVE HIGH RATES OF SUSTAINED VIROLOGIC RESPONSE; HOWEVER, THE HCC RISK REMAINS ELEVATED IN CURED PATIENTS, ESPECIALLY THOSE WITH ADVANCED LIVER DISEASE. LONG-TERM HCV INFECTION CAUSES A PERSISTENT AND ACCUMULATING DAMAGE OF THE LIVER DUE TO A COMBINATION OF DIRECT AND INDIRECT PRO-ONCOGENIC MECHANISMS. THIS REVIEW DESCRIBES THE PROCESSES INVOLVED IN VIRUS-INDUCED DISEASE PROGRESSION BY VIRAL PROTEINS, DERAILED SIGNALING, IMMUNITY, AND PERSISTENT EPIGENETIC DEREGULATION, WHICH MAY BE INSTRUMENTAL TO DEVELOP URGENTLY NEEDED PROGNOSTIC BIOMARKERS AND AS TARGETS FOR NOVEL CHEMOPREVENTIVE THERAPIES. 2020 12 3251 31 HEPATITIS B VIRUS INFECTION: AN INSIGHT INTO THE CLINICAL CONNECTION AND MOLECULAR INTERACTION BETWEEN HEPATITIS B VIRUS AND HOST EXTRAHEPATIC CANCER RISK. THE EVIDENCE FOR CHRONIC HEPATITIS B VIRUS (HBV) INFECTION AND HEPATOCELLULAR CARCINOMA (HCC) OCCURRENCE IS WELL ESTABLISHED. THE HEPATOCYTE EPITHELIUM CARCINOGENESIS CAUSED BY HBV HAS BEEN INVESTIGATED AND REVIEWED IN DEPTH. NEVERTHELESS, RECENT FINDINGS FROM PRECLINICAL AND OBSERVATIONAL STUDIES SUGGESTED THAT CHRONIC HBV INFECTION IS EQUALLY IMPORTANT IN EXTRAHEPATIC CANCER OCCURRENCE AND SURVIVAL, SPECIFICALLY GASTROINTESTINAL SYSTEM-DERIVED CANCERS. IMMUNE MICROENVIRONMENT CHANGES (IMMUNE-SUPPRESSIVE CYTOKINE INFILTRATION), EPIGENETIC MODIFICATION (N6-METHYLADENOSINE), MOLECULAR SIGNALING PATHWAYS (PI3K-AKT AND WNT), AND SERUM BIOMARKERS SUCH AS HEPATITIS B VIRUS X (HBX) PROTEIN ARE POTENTIAL UNDERLYING MECHANISMS IN CHRONIC HBV INFECTION-INDUCED EXTRAHEPATIC CANCERS. THIS NARRATIVE REVIEW AIMED TO COMPREHENSIVELY SUMMARIZE THE MOST RECENT ADVANCES IN EVALUATING THE ASSOCIATION BETWEEN CHRONIC HBV INFECTION AND EXTRAHEPATIC CANCER RISK AND EXPLORE THE POTENTIAL UNDERLYING MOLECULAR MECHANISMS IN THE CARCINOGENESIS INDUCTION OF EXTRAHEPATIC CANCERS IN CHRONIC HBV CONDITIONS. 2023 13 6271 31 THE ONCOGENIC ROLE OF HEPATITIS B VIRUS. THE HEPATITIS B VIRUS (HBV) IS A SMALL ENVELOPED DNA VIRUS THAT CAUSES ACUTE AND CHRONIC HEPATITIS. HBV INFECTION IS A WORLD HEALTH PROBLEM, WITH 350 MILLION CHRONICALLY INFECTED PEOPLE AT INCREASED RISK OF DEVELOPING LIVER DISEASE AND HEPATOCELLULAR CARCINOMA (HCC). HBV HAS BEEN CLASSIFIED AMONG HUMAN TUMOR VIRUSES BY VIRTUE OF A ROBUST EPIDEMIOLOGIC ASSOCIATION BETWEEN CHRONIC HBV CARRIAGE AND HCC OCCURRENCE. IN THE ABSENCE OF CYTOPATHIC EFFECT IN INFECTED HEPATOCYTES, THE ONCOGENIC ROLE OF HBV MIGHT INVOLVE A COMBINATION OF DIRECT AND INDIRECT EFFECTS OF THE VIRUS DURING THE MULTISTEP PROCESS OF LIVER CARCINOGENESIS. LIVER INFLAMMATION AND HEPATOCYTE PROLIFERATION DRIVEN BY HOST IMMUNE RESPONSES ARE RECOGNIZED DRIVING FORCES OF LIVER CELL TRANSFORMATION. GENETIC AND EPIGENETIC ALTERATIONS CAN ALSO RESULT FROM VIRAL DNA INTEGRATION INTO HOST CHROMOSOMES AND FROM PROLONGED EXPRESSION OF VIRAL GENE PRODUCTS. NOTABLY, THE TRANSCRIPTIONAL REGULATORY PROTEIN HBX ENCODED BY THE X GENE IS ENDOWED WITH TUMOR PROMOTER ACTIVITY. HBX HAS PLEIOTROPIC ACTIVITIES AND PLAYS A MAJOR ROLE IN HBV PATHOGENESIS AND IN LIVER CARCINOGENESIS. BECAUSE HEPATIC TUMORS CARRY A DISMAL PROGNOSIS, THERE IS URGENT NEED TO DEVELOP EARLY DIAGNOSTIC MARKERS OF HCC AND EFFECTIVE THERAPIES AGAINST CHRONIC HEPATITIS B. DECIPHERING THE ONCOGENIC MECHANISMS THAT UNDERLIE HBV-RELATED TUMORIGENESIS MIGHT HELP DEVELOPING ADAPTED THERAPEUTIC STRATEGIES. 2014 14 6707 36 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 15 4476 25 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 16 4449 34 MOLECULAR MECHANISM OF HEPATITIS B VIRUS-INDUCED HEPATOCARCINOGENESIS. HEPATITIS B VIRUS (HBV) INFECTION IS A GLOBAL PUBLIC HEALTH PROBLEM WITH APPROXIMATELY 2 BILLION PEOPLE THAT HAVE BEEN EXPOSED TO THE VIRUS. HBV IS A MEMBER OF A FAMILY OF SMALL, ENVELOPED DNA VIRUSES CALLED HEPADNAVIRUSES, AND HAS A PREFERENTIAL TROPISM FOR HEPATOCYTES OF MAMMALS AND BIRDS. EPIDEMIOLOGICAL STUDIES HAVE PROVED A STRONG CORRELATION BETWEEN CHRONIC HEPATITIS B VIRUS INFECTION AND THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC). HCC IS THE FIFTH MOST COMMON MALIGNANCY WITH ABOUT 700000 NEW CASES EACH YEAR, AND MORE THAN 50% OF THEM ARISE IN HBV CARRIERS. A LARGE NUMBER OF STUDIES DESCRIBE THE WAY IN WHICH HBV CAN CONTRIBUTE TO HCC DEVELOPMENT. MULTIPLE MECHANISMS HAVE BEEN PROPOSED, INCLUDING THE ACCUMULATION OF GENETIC DAMAGE DUE TO IMMUNE-MEDIATED HEPATIC INFLAMMATION AND THE INDUCTION OF OXIDATIVE STRESS. THERE IS EVIDENCE OF THE DIRECT EFFECTS OF THE VIRAL PROTEINS HBX AND HBS ON THE CELL BIOLOGY. INTEGRATION OF HBV-DNA INTO THE HUMAN GENOME IS CONSIDERED AN EARLY EVENT IN THE CARCINOGENIC PROCESS AND CAN INDUCE, THROUGH INSERTIONAL MUTAGENESIS, THE ALTERATION OF GENE EXPRESSION AND CHROMOSOMAL INSTABILITY. HBV HAS ALSO EPIGENETIC EFFECTS THROUGH THE MODIFICATION OF THE GENOMIC METHYLATION STATUS. FURTHERMORE, THE VIRUS PLAYS AN IMPORTANT ROLE IN THE REGULATION OF MICRORNA EXPRESSION. THIS REVIEW WILL SUMMARIZE THE MANY MECHANISMS INVOLVED IN HBV-RELATED LIVER CARCINOGENESIS. 2014 17 6016 31 THE ASSOCIATION BETWEEN HEPATOCARCINOGENESIS AND INTRACELLULAR ALTERATIONS DUE TO HEPATITIS B VIRUS INFECTION. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IS A WORLDWIDE HEALTH PROBLEM LEADING TO SEVERE LIVER DYSFUNCTION, INCLUDING LIVER CIRRHOSIS AND HEPATOCELLULAR CARCINOMA. ALTHOUGH CURRENT ANTIVIRAL THERAPIES FOR CHRONIC HBV INFECTION HAVE BEEN IMPROVED AND CAN LEAD TO A STRONG SUPPRESSION OF VIRAL REPLICATION, IT IS DIFFICULT TO COMPLETELY ELIMINATE THE VIRUS WITH THESE THERAPIES ONCE CHRONIC HBV INFECTION IS ESTABLISHED IN THE HOST. FURTHERMORE, CHRONIC HBV INFECTION ALTERS INTRACELLULAR METABOLISM AND SIGNALLING PATHWAYS, RESULTING IN THE ACTIVATION OF CARCINOGENESIS IN THE LIVER. HBV PRODUCES FOUR VIRAL PROTEINS: HEPATITIS B SURFACE-, HEPATITIS B CORE-, HEPATITIS B X PROTEIN, AND POLYMERASE; EACH PLAYS AN IMPORTANT ROLE IN HBV REPLICATION AND THE INTRACELLULAR SIGNALLING PATHWAYS ASSOCIATED WITH HEPATOCARCINOGENESIS. IN VITRO AND IN VIVO EXPERIMENTAL MODELS FOR ANALYZING HBV INFECTION AND REPLICATION HAVE BEEN ESTABLISHED, AND GENE EXPRESSION ANALYSES USING MICROARRAYS OR NEXT-GENERATION SEQUENCING HAVE ALSO BEEN DEVELOPED. THUS, IT IS POSSIBLE TO CLARIFY THE MOLECULAR MECHANISMS FOR INTRACELLULAR ALTERATIONS, SUCH AS ENDOPLASMIC RETICULUM STRESS, OXIDATIVE STRESS, AND EPIGENETIC MODIFICATIONS. IN THIS REVIEW, THE IMPACT OF HBV VIRAL PROTEINS AND INTRACELLULAR ALTERATIONS IN HBV-ASSOCIATED HEPATOCARCINOGENESIS ARE DISCUSSED. 2021 18 3254 26 HEPATITIS B VIRUS X PROTEIN AND HEPATOCARCINOGENESIS. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IS ONE OF THE MOST ASSOCIATED FACTORS IN HEPATOCARCINOGENESIS. HBV IS ABLE TO INTEGRATE INTO THE HOST GENOME AND ENCODE THE MULTI-FUNCTIONAL HEPATITIS B VIRUS X PROTEIN (HBX). ALTHOUGH THE MECHANISM BETWEEN HBX AND CARCINOGENESIS IS STILL ELUSIVE, RECENT STUDIES HAVE SHOWN THAT HBX WAS ABLE TO INFLUENCE VARIOUS SIGNALING PATHWAYS, AS WELL AS EPIGENETIC AND GENETIC PROCESSES. THIS REVIEW WILL EXAMINE AND SUMMARIZE RECENT LITERATURE ABOUT HBX'S ROLE IN THESE VARIOUS PROCESSES. 2016 19 5233 34 PROFIBROTIC SIGNALING AND HCC RISK DURING CHRONIC VIRAL HEPATITIS: BIOMARKER DEVELOPMENT. DESPITE BREAKTHROUGHS IN ANTIVIRAL THERAPIES, CHRONIC VIRAL HEPATITIS B AND C ARE STILL THE MAJOR CAUSES OF LIVER FIBROSIS AND HEPATOCELLULAR CARCINOMA (HCC). IMPORTANTLY, EVEN IN PATIENTS WITH CONTROLLED INFECTION OR VIRAL CURE, THE CANCER RISK CANNOT BE FULLY ELIMINATED, HIGHLIGHTING A PERSISTING ONCOGENIC PRESSURE IMPOSED BY EPIGENETIC IMPRINTING AND ADVANCED LIVER DISEASE. RELIABLE AND MINIMALLY INVASIVE BIOMARKERS FOR EARLY FIBROSIS AND FOR RESIDUAL HCC RISK IN HCV-CURED PATIENTS ARE URGENTLY NEEDED. CHRONIC INFECTION WITH HBV AND/OR HCV DYSREGULATES ONCOGENIC AND PROFIBROGENIC SIGNALING WITHIN THE HOST, ALSO DISPLAYED IN THE SECRETION OF SOLUBLE FACTORS TO THE BLOOD. THE STUDY OF VIRUS-DYSREGULATED SIGNALING PATHWAYS MAY, THEREFORE, CONTRIBUTE TO THE IDENTIFICATION OF RELIABLE MINIMALLY INVASIVE BIOMARKERS FOR THE DETECTION OF PATIENTS AT EARLY-STAGE LIVER DISEASE POTENTIALLY COMPLEMENTING EXISTING NONINVASIVE METHODS IN CLINICS. WITH A FOCUS ON VIRUS-INDUCED SIGNALING EVENTS, THIS REVIEW PROVIDES AN OVERVIEW OF CANDIDATE BLOOD BIOMARKERS FOR LIVER DISEASE AND HCC RISK ASSOCIATED WITH CHRONIC VIRAL HEPATITIS AND EPIGENETIC VIRAL FOOTPRINTS. 2021 20 4475 40 MOLECULAR PATHOGENESIS OF HEPATITIS C VIRUS-ASSOCIATED HEPATOCELLULAR CARCINOMA. CHRONIC INFECTION WITH HEPATITIS C VIRUS (HCV) IS CAUSALLY ASSOCIATED WITH THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC). HCV IS NOT CYTOLYTIC AND REPLICATES ENTIRELY IN THE CYTOPLASM. VIRAL INTERACTION WITH THE HOST LEADS TO SUBVERSION OF IMMUNE RESPONSE AND OTHER DEFENSE MECHANISMS. THE RECENT DEVELOPMENT OF ROBUST CELL CULTURE SYSTEMS FOR HCV INFECTION PROVIDES NEW OPPORTUNITIES FOR THE STUDY OF VIRUS-CELL INTERACTION AND VIRAL PATHOGENESIS. HCV INFECTION CAUSES ACTIVE INFLAMMATION AND FIBROSIS, WHICH ULTIMATELY PROGRESSES TO CIRRHOSIS. THE ONSET OF CIRRHOSIS USUALLY PRECEDES THE MULTISTAGE PROCESS OF TUMOR DEVELOPMENT, IN WHICH COMMON THEMES OF VIRAL CARCINOGENESIS CAN BE IDENTIFIED. WHILE CHRONIC INFLAMMATION AND CIRRHOSIS ARE THOUGHT TO PLAY AN IMPORTANT ROLE IN TUMOR INITIATION, THE UNDERLYING MECHANISMS ARE INCOMPLETELY UNDERSTOOD. RECENT STUDIES HAVE REVEALED THAT INFECTION WITH HCV INDUCES GENOME INSTABILITY, LEADING TO FURTHER GENETIC AND EPIGENETIC ALTERATIONS WHICH CONTRIBUTE TO THE FULL DEVELOPMENT OF HCC TUMOR. THE EXPRESSION OF VIRAL ONCOPROTEINS SUCH AS C AND NS5A IS CRITICALLY INVOLVED BOTH IN THE INDUCTION OF GENOME INSTABILITY AND IN DYSREGULATING CELLULAR CONTROL OF GROWTH AND SIGNAL TRANSDUCTION. A BETTER UNDERSTANDING OF THE MOLECULAR PATHOGENESIS OF HCV WILL REVEAL NOVEL STRATEGIES FOR THE PREVENTION AND TREATMENT OF RELATED DISEASES INCLUDING HCC. 2007