1 1042 86 CLINICAL AND MOLECULAR BASIS OF HEPATOCELLULAR CARCINOMA AFTER HEPATITIS C VIRUS ERADICATION. HEPATOCELLULAR CARCINOMA (HCC) ARISES IN THE BACKGROUND OF CHRONIC LIVER DISEASES, INCLUDING HEPATITIS AND LIVER CIRRHOSIS CAUSED BY HEPATITIS C VIRUS (HCV) INFECTION. IT IS WELL KNOWN THAT HCV ERADICATION USING ANTIVIRAL DRUGS CAN EFFICIENTLY INHIBIT HEPATOCARCINOGENESIS. RECENT ADVANCES IN AND DEVELOPMENT OF DIRECT-ACTING ANTIVIRAL (DAA) DRUGS HAS REVOLUTIONIZED THE TREATMENT OF HCV INFECTION, AND THE VAST MAJORITY OF HCV PATIENTS CAN ACHIEVE HCV ERADICATION USING DAAS. HOWEVER, MOUNTING EVIDENCE CLEARLY INDICATES THAT HCC INEVITABLY OCCURS IN A SUBSET OF PATIENTS AFTER SUCCESSFUL VIRAL ERADICATION USING DAA THERAPY. CANCER IS A GENETIC DISEASE, AND THE ACCUMULATION OF GENETIC AND EPIGENETIC ABERRATIONS MAY CAUSE HEPATOCARCINOGENESIS IN CHRONICALLY DAMAGED LIVER, EVEN AFTER VIRUS ELIMINATION. IN THIS REVIEW, WE HIGHLIGHT HCC DEVELOPMENT AFTER HCV ERADICATION AND DISCUSS THE CURRENT UNDERSTANDING OF THE MOLECULAR MECHANISMS OF TUMORIGENESIS AFTER VIRUS ELIMINATION, FOCUSING ON THE GENETIC AND EPIGENETIC BACKGROUND OF CHRONICALLY DAMAGED LIVER TISSUES. 2022 2 3190 37 HCV-INDUCED EPIGENETIC CHANGES ASSOCIATED WITH LIVER CANCER RISK PERSIST AFTER SUSTAINED VIROLOGIC RESPONSE. BACKGROUND & AIMS: CHRONIC HEPATITIS C VIRUS (HCV) INFECTION IS AN IMPORTANT RISK FACTOR FOR HEPATOCELLULAR CARCINOMA (HCC). DESPITE EFFECTIVE ANTIVIRAL THERAPIES, THE RISK FOR HCC IS DECREASED BUT NOT ELIMINATED AFTER A SUSTAINED VIROLOGIC RESPONSE (SVR) TO DIRECT-ACTING ANTIVIRAL (DAA) AGENTS, AND THE RISK IS HIGHER IN PATIENTS WITH ADVANCED FIBROSIS. WE INVESTIGATED HCV-INDUCED EPIGENETIC ALTERATIONS THAT MIGHT AFFECT RISK FOR HCC AFTER DAA TREATMENT IN PATIENTS AND MICE WITH HUMANIZED LIVERS. METHODS: WE PERFORMED GENOME-WIDE CHIPMENTATION-BASED CHIP-SEQ AND RNA-SEQ ANALYSES OF LIVER TISSUES FROM 6 PATIENTS WITHOUT HCV INFECTION (CONTROLS), 18 PATIENTS WITH CHRONIC HCV INFECTION, 8 PATIENTS WITH CHRONIC HCV INFECTION CURED BY DAA TREATMENT, 13 PATIENTS WITH CHRONIC HCV INFECTION CURED BY INTERFERON THERAPY, 4 PATIENTS WITH CHRONIC HEPATITIS B VIRUS INFECTION, AND 7 PATIENTS WITH NONALCOHOLIC STEATOHEPATITIS IN EUROPE AND JAPAN. HCV-INDUCED EPIGENETIC MODIFICATIONS WERE MAPPED BY COMPARATIVE ANALYSES WITH MODIFICATIONS ASSOCIATED WITH OTHER LIVER DISEASE ETIOLOGIES. UPA/SCID MICE WERE ENGRAFTED WITH HUMAN HEPATOCYTES TO CREATE MICE WITH HUMANIZED LIVERS AND GIVEN INJECTIONS OF HCV-INFECTED SERUM SAMPLES FROM PATIENTS; MICE WERE GIVEN DAAS TO ERADICATE THE VIRUS. PATHWAYS ASSOCIATED WITH HCC RISK WERE IDENTIFIED BY INTEGRATIVE PATHWAY ANALYSES AND VALIDATED IN ANALYSES OF PAIRED HCC TISSUES FROM 8 PATIENTS WITH AN SVR TO DAA TREATMENT OF HCV INFECTION. RESULTS: WE FOUND CHRONIC HCV INFECTION TO INDUCE SPECIFIC GENOME-WIDE CHANGES IN H3K27AC, WHICH CORRELATED WITH CHANGES IN EXPRESSION OF MRNAS AND PROTEINS. THESE CHANGES PERSISTED AFTER AN SVR TO DAAS OR INTERFERON-BASED THERAPIES. INTEGRATIVE PATHWAY ANALYSES OF LIVER TISSUES FROM PATIENTS AND MICE WITH HUMANIZED LIVERS DEMONSTRATED THAT HCV-INDUCED EPIGENETIC ALTERATIONS WERE ASSOCIATED WITH LIVER CANCER RISK. COMPUTATIONAL ANALYSES ASSOCIATED INCREASED EXPRESSION OF SPHK1 WITH HCC RISK. WE VALIDATED THESE FINDINGS IN AN INDEPENDENT COHORT OF PATIENTS WITH HCV-RELATED CIRRHOSIS (N = 216), A SUBSET OF WHICH (N = 21) ACHIEVED VIRAL CLEARANCE. CONCLUSIONS: IN AN ANALYSIS OF LIVER TISSUES FROM PATIENTS WITH AND WITHOUT AN SVR TO DAA THERAPY, WE IDENTIFIED EPIGENETIC AND GENE EXPRESSION ALTERATIONS ASSOCIATED WITH RISK FOR HCC. THESE ALTERATIONS MIGHT BE TARGETED TO PREVENT LIVER CANCER IN PATIENTS TREATED FOR HCV INFECTION. 2019 3 442 27 ANTIVIRAL THERAPIES FOR HEPATITIS B VIRUS-RELATED HEPATOCELLULAR CARCINOMA. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IS A CRITICAL RISK FACTOR FOR THE CARCINOGENESIS AND PROGRESSION OF HEPATOCELLULAR CARCINOMA (HCC). IT PROMOTES HCC DEVELOPMENT BY INDUCING LIVER FIBROGENESIS, GENETIC AND EPIGENETIC ALTERATIONS, AND THE EXPRESSION OF ACTIVE VIRAL-CODED PROTEINS. EFFECTIVE ANTIVIRAL TREATMENTS INHIBIT THE REPLICATION OF HBV, REDUCE SERUM VIRAL LOAD AND ACCELERATE HEPATITIS B E ANTIGEN SERUM CONVERSION. TIMELY INITIATION OF ANTIVIRAL TREATMENT IS NOT ONLY ESSENTIAL FOR PREVENTING THE INCIDENCE OF HCC IN CHRONIC HEPATITIS B PATIENTS, BUT ALSO IMPORTANT FOR REDUCING HBV REACTIVATION, IMPROVING LIVER FUNCTION, REDUCING OR DELAYING HCC RECURRENCE, AND PROLONGING OVERALL SURVIVAL OF HBV-RELATED HCC PATIENTS AFTER CURATIVE AND PALLIATIVE THERAPIES. THE SELECTION OF ANTIVIRAL DRUGS, MONITORING OF INDICATORS SUCH AS HBV DNA AND HEPATITIS B SURFACE ANTIGEN, AND TIMELY RESCUE TREATMENT WHEN NECESSARY, ARE ESSENTIAL IN ANTIVIRAL THERAPIES FOR HBV-RELATED HCC. 2015 4 6868 21 [PATHOGENESIS OF HEPATITIS B VIRUS-RELATED HEPATOCELLULAR CARCINOMA]. HEPATOCELLULAR CARCINOMA (HCC) IS ONE OF THE MOST COMMON CANCER WORLDWIDE. MOST OF THE HCC OCCUR IN DEVELOPING COUNTRIES. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IS AN IMPORTANT RISK FACTOR FOR HCC DEVELOPMENT. HBV INDUCES IMMUNE-MEDIATED CHRONIC HEPATITIS, LIVER INJURY, REGENERATION AND SCAR FORMING RESPONSES, LEADING TO AN INFLAMMATORY, FIBROTIC AND IMMUNE DEFICIENT MICROENVIRONMENT. HBV MAY INTEGRATE INTO HOST GENOME, INDUCING GENETIC ABNORMALITY AND ALTERING THE EXPRESSION OF HCC-RELATED GENES. HBV ALSO EXPRESSES ACTIVE PROTEINS SUCH AS X (HBX) AND S PROTEINS, WHICH MAY TRANS-ACTIVATE HCC-RELATED PROTEINS EXPRESSION, INTERACT WITH INTRACELLULAR SPECIFIC PROTEINS, ACTIVATE A VARIETY OF SIGNALING PATHWAYS, AND INDUCE ABERRANT EPIGENETIC MODIFICATIONS. HBV MUTATION ALSO HAS IMPACT ON HBV RELATED HCC DEVELOPMENT. 2016 5 3259 33 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 6 4903 23 P16 PROMOTER HYPERMETHYLATION IN HUMAN HEPATOCELLULAR CARCINOMA WITH OR WITHOUT HEPATITIS VIRUS INFECTION. BACKGROUND: EPIGENETIC ALTERATION THROUGH METHYLATION IS ONE OF THE MOST IMPORTANT STEPS IN CARCINOGENESIS. HOWEVER, THE RELATION BETWEEN HEPATITIS VIRUS INFECTION AND EPIGENETIC ALTERATIONS IS POORLY UNDERSTOOD. METHODS: SIXTEEN PATIENTS WITHOUT HEPATITIS B VIRUS (HBV) AND HEPATITIS C VIRUS (HCV) AND 35 PATIENTS WITH HBV OR HCV WHO UNDERWENT LIVER RESECTION FOR HEPATOCELLULAR CARCINOMA (HCC) WERE STUDIED. MUTATION OF P53 WAS DETECTED BY DIRECT SEQUENCING. METHYLATION STATUS OF P16 WAS EVALUATED IN TUMOR AND NONCANCEROUS LIVER TISSUES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. RESULTS: IN HCC WITHOUT HBV AND HCV, P53 MUTATIONS WERE DETECTED IN 5 (31%) OF 16 HCCS. METHYLATION OF P16 PROMOTER WAS DETECTED IN 2 (25%) OF 8 MODERATELY DIFFERENTIATED HCCS, 6 (75%) OF 8 POORLY DIFFERENTIATED HCCS, AND NONE OF 16 NONCANCEROUS TISSUE SPECIMENS. IN HCC WITH HBV OR HCV, P53 MUTATIONS WERE DETECTED IN 8 (23%) OF 35 HCCS. METHYLATION OF P16 PROMOTER WAS DETECTED IN 2 (100%) OF 2 WELL-DIFFERENTIATED HCCS, 13 (76%) OF 17 MODERATELY DIFFERENTIATED HCCS, 12 (75%) OF 16 POORLY DIFFERENTIATED HCCS, AND 9 (26%) OF 35 NONCANCEROUS LIVER TISSUE SPECIMENS. CONCLUSIONS: OUR RESULTS SUGGEST THAT HEPATITIS VIRUSES MIGHT INDUCE METHYLATION OF P16 PROMOTER IN LIVER WITH CHRONIC INFLAMMATION, BEFORE APPEARANCE OF HCC. 2004 7 4454 31 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 8 4815 30 OCCULT HEPATITIS B INFECTION AND HEPATOCELLULAR CARCINOMA: EPIDEMIOLOGY, VIROLOGY, HEPATOCARCINOGENESIS AND CLINICAL SIGNIFICANCE. OCCULT HEPATITIS B INFECTION (OBI) REFERS TO A CONDITION WHERE REPLICATION-COMPETENT HBV DNA IS PRESENT IN THE LIVER, WITH OR WITHOUT HBV DNA IN THE BLOOD, IN INDIVIDUALS WITH SERUM HBSAG NEGATIVITY ASSESSED BY CURRENTLY AVAILABLE ASSAYS. THE EPISOMAL COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) IN OBI IS IN A LOW REPLICATIVE STATE. VIRAL GENE EXPRESSION IS MEDIATED BY EPIGENETIC CONTROL OF HBV TRANSCRIPTION, INCLUDING THE HBV CPG ISLAND METHYLATION PATHWAY AND POST-TRANSLATIONAL MODIFICATION OF CCCDNA-BOUND HISTONE, WITH A DIFFERENT PATTERN FROM PATIENTS WITH CHRONIC HBV INFECTION. THE PREVALENCE OF OBI VARIES TREMENDOUSLY ACROSS PATIENT POPULATIONS OWING TO NUMEROUS FACTORS, SUCH AS GEOGRAPHIC LOCATION, ASSAY CHARACTERISTICS, HOST IMMUNE RESPONSE, COINFECTION WITH OTHER VIRUSES, AND VACCINATION STATUS. APART FROM THE RISK OF VIRAL REACTIVATION UPON IMMUNOSUPPRESSION AND THE RISK OF TRANSMISSION OF HBV, OBI HAS BEEN IMPLICATED IN HEPATOCELLULAR CARCINOMA (HCC) DEVELOPMENT IN PATIENTS WITH CHRONIC HCV INFECTION, THOSE WITH CRYPTOGENIC OR KNOWN LIVER DISEASE, AND IN PATIENTS WITH HBSAG SEROCLEARANCE AFTER CHRONIC HBV INFECTION. AN INCREASING NUMBER OF PROSPECTIVE STUDIES AND META-ANALYSES HAVE REPORTED A HIGHER INCIDENCE OF HCC IN PATIENTS WITH HCV AND OBI, AS WELL AS MORE ADVANCED TUMOUR HISTOLOGICAL GRADES AND EARLIER AGE OF HCC DIAGNOSIS, COMPARED WITH PATIENTS WITHOUT OBI. THE PROPOSED PATHOGENETIC MECHANISMS OF OBI-RELATED HCC INCLUDE THE INFLUENCE OF HBV DNA INTEGRATION ON THE HEPATOCYTE CELL CYCLE, THE PRODUCTION OF PRO-ONCOGENIC PROTEINS (HBX PROTEIN AND MUTATED SURFACE PROTEINS), AND PERSISTENT LOW-GRADE NECROINFLAMMATION (CONTRIBUTING TO THE DEVELOPMENT OF FIBROSIS AND CIRRHOSIS). THERE REMAIN UNCERTAINTIES ABOUT EXACTLY HOW, AND IN WHAT ORDER, THESE MECHANISMS DRIVE THE DEVELOPMENT OF TUMOURS IN PATIENTS WITH OBI. 2020 9 42 28 A COMPREHENSIVE GENOME-WIDE PROFILING COMPARISON BETWEEN HBV AND HCV INFECTED HEPATOCELLULAR CARCINOMA. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC) IS ONE OF THE MOST COMMON CANCERS WORLDWIDE, ESPECIALLY IN EAST ASIA. EVEN WITH THE PROGRESS IN THERAPY, 5-YEAR SURVIVAL RATES REMAIN UNSATISFIED. CHRONIC INFECTION WITH THE HEPATITIS B VIRUS (HBV) OR HEPATITIS C VIRUS (HCV) HAS BEEN EPIDEMIOLOGICALLY ASSOCIATED WITH HCC AND IS THE MAJOR ETIOLOGY IN THE EAST ASIAN POPULATION. THE DETAILED MECHANISM, ESPECIALLY THE CHANGES OF DNA METHYLATION AND GENE EXPRESSION BETWEEN THE TWO TYPES OF VIRUS-RELATED HCC, AND THEIR CONTRIBUTIONS TO THE HCC DEVELOPMENT, METASTASIS, AND RECURRENCE REMAIN LARGELY UNKNOWN. METHODS: IN THIS INTEGRATED ANALYSIS, WE CHARACTERIZED GENOME-SCALE PROFILES OF HBV AND HCV INFECTED HCC BY COMPARING THEIR GENE EXPRESSION PATTERN, METHYLATION PROFILES, AND COPY NUMBER VARIATIONS FROM THE PUBLICLY ACCESSIBLE DATA OF THE CANCER GENOME ATLAS PROGRAM (TCGA). RESULTS: THE HLA-A, STAT1, AND OAS2 GENES WERE HIGHLY ENRICHED AND UP-REGULATED DISCOVERED IN THE HCV-INFECTED HCC. HYPOMETHYLATION BUT NOT COPY NUMBER VARIATIONS MIGHT BE THE MAJOR FACTOR FOR THE UP-REGULATION OF THESE IMMUNE-RELATED GENES IN HCV-INFECTED HCC. CONCLUSIONS: THE RESULTS INDICATED THE DIFFERENT EPIGENETIC CHANGES OF HBV/HCV RELATED HEPATOCARCINOGENESIS. THE TOP UP-REGULATED GENES IN HCV GROUP WERE SIGNIFICANTLY CLUSTERED IN THE IMMUNE-RELATED AND DEFENSE RESPONSE PATHWAYS. THESE FINDINGS WILL HELP US TO UNDERSTAND THE PATHOGENESIS OF HBV/HCV ASSOCIATED HEPATOCELLULAR CARCINOMA. 2019 10 3255 21 HEPATITIS B VIRUS X PROTEIN MEDIATED EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF HEPATOCELLULAR CARCINOMA. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IS A WORLDWIDE HEALTH PROBLEM. HEPATITIS B VIRUS X PROTEIN (HBX), A PLEIOTROPIC REGULATORY PROTEIN ENCODED BY HBV, IS NECESSARY FOR THE TRANSCRIPTION OF HBV COVALENTLY CLOSED CIRCULAR DNA (CCCDNA) MINICHROMOSOMES, AND AFFECTS THE EPIGENETIC REGULATION OF HOST CELLS. THE EPIGENETIC REPROGRAMMING OF HBX ON HOST CELL GENOME IS STRONGLY INVOLVED IN HBV-RELATED HCC CARCINOGENESIS. HERE, WE REVIEW THE LATEST FINDINGS OF THE EPIGENETIC REGULATION INDUCED BY HBX PROTEIN IN HEPATOCELLULAR CARCINOMA (HCC), INCLUDING DNA METHYLATION, HISTONE MODIFICATION AND NON-CODING RNA EXPRESSION. THE INFLUENCE OF HBX ON THE EPIGENETIC REGULATION OF CCCDNA IS ALSO SUMMARIZED. IN ADDITION, PRELIMINARY STUDIES OF TARGETED DRUGS FOR EPIGENETIC CHANGES INDUCED BY HBX ARE ALSO DISCUSSED. THE EXPLORATION OF EPIGENETIC MARKERS AS POTENTIAL TARGETS WILL HELP TO DEVELOP NEW PREVENTION AND/OR TREATMENT METHODS FOR HBX-RELATED HCC. 2022 11 3394 30 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 12 6829 35 [HEPATITIS C VIRUS INFECTION AND HEPATOCARCINOGENESIS]. HEPATITIS C VIRUS INFECTION CAUSES APPROXIMATELY 4 MILLION NEW INFECTIONS WORLDWIDE, AND 399 000 DEATHS DUE TO ITS COMPLICATIONS, CIRRHOSIS AND HEPATOCELLULAR CARCINOMA (HCC). MICROENVIRONMENTAL CHANGES, CHRONIC INFLAMMATION, OXIDATIVE STRESS, ENDOPLASMIC RETICULUM STRESS CAUSED BY HCV INFECTION, VIA GENETIC AND EPIGENETIC CHANGES CAN RESULT IN PRIMARY LIVER CANCER DURING DECADES. THE DIRECT ONCOGENIC PROPERTY OF HCV IS WELLKNOWN. THE TRANSFORMING EFFECT OF FOUR HCV PROTEINS (CORE, NS3, NS4B, NS5A) HAS BEEN PROVEN. EFFECTIVE ANTIVIRAL THERAPY, SUSTAINED VIRAL RESPONSE DECREASES THE HCV-RELATED GENERAL AND LIVER-RELATED MORTALITY. INTERFERON-BASED THERAPY REDUCES THE RISK OF HCC DEVELOPMENT. SHORTER THERAPY WITH DIRECT ACTING ANTIVIRAL AGENTS (DAA) HAS HIGHER EFFICACY, FEWER SIDE-EFFECTS. PUBLICATIONS HAVE REPORTED THE UNEXPECTED EFFECTS OF DAA. THE AUTHORS REVIEW THE ARTICLES FOCUSING ON THE OCCURRENCE OF HCC IN CONNECTION WITH DAA THERAPIES. THERE IS A NEED FOR PROSPECTIVE, MULTICENTRIC STUDIES WITH LONGER FOLLOW-UP TO EXAMINE THE RISK OF HCC FORMATION. AFTER ANTIVIRAL THERAPY, HCC SURVEILLANCE IS OF HIGH IMPORTANCE WHICH MEANS ABDOMINAL ULTRASOUND EVERY 3-6-12 MONTHS IN SUSTAINED VIRAL RESPONSE PATIENTS AS WELL. ORV HETIL. 2019; 160(22): 846-853. 2019 13 2980 38 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 14 3274 34 HEPATOCELLULAR CARCINOMA: THE VIRUS OR THE LIVER? HEPATOCELLULAR CARCINOMA (HCC) REPRESENTS A MAJOR PUBLIC HEALTH PROBLEM BEING ONE OF THE MOST COMMON CAUSES OF CANCER-RELATED DEATHS WORLDWIDE. HEPATITIS B (HBV) AND C VIRUSES HAVE BEEN CLASSIFIED AS ONCOVIRUSES AND ARE RESPONSIBLE FOR THE MAJORITY OF HCC CASES, WHILE THE ROLE OF HEPATITIS D VIRUS (HDV) IN LIVER CARCINOGENESIS HAS NOT BEEN ELUCIDATED. HDV/HBV COINFECTION IS RELATED TO MORE SEVERE LIVER DAMAGE THAN HBV MONO-INFECTION AND RECENT STUDIES SUGGEST THAT HDV/HBV PATIENTS ARE AT INCREASED RISK OF DEVELOPING HCC COMPARED TO HBV MONO-INFECTED PATIENTS. HBV IS KNOWN TO PROMOTE HEPATOCARCINOGENESIS VIA DNA INTEGRATION INTO HOST DNA, DISRUPTION OF MOLECULAR PATHWAYS BY REGULATORY HBV X (HBX) PROTEIN AND EXCESSIVE OXIDATIVE STRESS. RECENTLY, SEVERAL MOLECULAR MECHANISMS HAVE BEEN PROPOSED TO CLARIFY THE PATHOGENESIS OF HDV-RELATED HCC INCLUDING ACTIVATION OF SIGNALLING PATHWAYS BY SPECIFIC HDV ANTIGENS, EPIGENETIC DYSREGULATION AND ALTERED GENE EXPRESSION. ALONGSIDE, ONGOING CHRONIC INFLAMMATION AND IMPAIRED IMMUNE RESPONSES HAVE ALSO BEEN SUGGESTED TO FACILITATE CARCINOGENESIS. FINALLY, CELLULAR SENESCENCE SEEMS TO PLAY AN IMPORTANT ROLE IN CHRONIC VIRAL INFECTION AND INFLAMMATION LEADING TO HEPATOCARCINOGENESIS. IN THIS REVIEW, WE SUMMARIZE THE CURRENT LITERATURE ON THE IMPACT OF HDV IN HCC DEVELOPMENT AND DISCUSS THE POTENTIAL INTERPLAY BETWEEN HBV, HDV AND NEIGHBOURING LIVER TISSUE IN LIVER CARCINOGENESIS. 2023 15 6486 28 TP53 AND LIVER CARCINOGENESIS. PRIMARY HEPATOCELLULAR CARCINOMA (HCC) IS ONE OF THE MOST COMMON MALIGNANCIES AND HAS THE FOURTH HIGHEST MORTALITY RATE WORLDWIDE. THE MAJOR RISK FACTORS, INCLUDING CHRONIC INFECTIONS WITH THE HEPATITIS B OR C VIRUS, ARE EXPOSURE TO DIETARY AFLATOXIN B1(AFB1), VINYL CHLORIDE, OR ALCOHOL CONSUMPTION. SOUTHERN CHINA AND SUB-SAHARAN AFRICA HAVE THE HIGHEST DIETARY AFB1 EXPOSURE, MAKING IT AND HEPATITIS B VIRUS (HBV) THE MAJOR CAUSES OF CANCER MORTALITY IN THESE GEOGRAPHIC AREAS. RECENT STUDIES HAVE DISCOVERED GENETIC AND EPIGENETIC CHANGES INVOLVED IN THE MOLECULAR PATHOGENESIS OF HCC, INCLUDING SOMATIC MUTATIONS IN THE P53 TUMOR SUPPRESSOR GENE (TP53). AFB1 INDUCES TYPICAL G:C TO T:A TRANSVERSIONS AT THE THIRD BASE IN CODON 249 OF P53. CHRONIC ACTIVE HEPATITIS B AND C (HCV) INFECTION, AND FURTHER INFLAMMATORY AND OXYRADICAL DISORDERS INCLUDING WILSON DISEASE (WD) OR HEMOCHROMATOSIS, GENERATE REACTIVE OXYGEN/NITROGEN SPECIES THAT CAN DAMAGE DNA AND MUTATE THE P53 GENE. THE X GENE OF HBV (HBX) IS THE MOST COMMON OPEN READING FRAME INTEGRATED INTO THE HOST GENOME IN HCC. THE INTEGRATED HBX IS FREQUENTLY MUTATED AND HAS A DIMINISHED ABILITY TO FUNCTION AS A TRANSCRIPTIONAL COTRANSACTIVATOR AND TO ACTIVATE THE NF-KAPPA B PATHWAY. HOWEVER, THE MUTANT HBX PROTEINS STILL RETAIN THEIR ABILITY TO BIND TO AND ABROGATE P53-MEDIATED APOPTOSIS. IN SUMMARY, BOTH VIRUSES AND CHEMICALS ARE IMPLICATED IN THE ETIOLOGY AND MOLECULAR PATHOGENESIS OF HCC. THE RESULTANT MOLECULAR CHANGES IN THE RAS AND WNT SIGNAL-TRANSDUCTION PATHWAYS, AND THE P53 AND RB TUMOR SUPPRESSOR PATHWAYS SIGNIFICANTLY CONTRIBUTE TO LIVER CARCINOGENESIS 2003 16 6271 26 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 17 3187 30 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 18 3254 19 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 1478 24 DIVERSE ROLES OF HEPATITIS B VIRUS IN LIVER CANCER. HEPATITIS B VIRUS (HBV) IS A WIDESPREAD HUMAN PATHOGEN RESPONSIBLE FOR ACUTE AND CHRONIC LIVER DISEASES. THE HEPATITIS B BURDEN IS PARTICULARLY HEAVY IN ENDEMIC COUNTRIES, WHERE LIVER CIRRHOSIS AND HEPATOCELLULAR CARCINOMA ARE LEADING CAUSES OF DEATH. HOWEVER, THE ONCOGENIC ROLE OF HBV REMAINS ENIGMATIC. AS THE VIRUS HAS NO CYTOPATHIC EFFECT, LIVER DAMAGE IS ATTRIBUTED TO IMMUNE RESPONSES THAT INDUCE INFLAMMATION, APOPTOSIS AND REGENERATION, FOSTERING THE ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS. IN A MORE DIRECT ACTION, FREQUENT INTEGRATION OF HBV DNA INTO HOST CHROMOSOMES MAY LEAD TO INSERTIONAL MUTAGENESIS OF CANCER-RELATED GENES AND CHROMOSOMAL INSTABILITY. HBV PROTEINS, NOTABLY THE HBX TRANSACTIVATOR, PARTICIPATE AS CO-FACTORS IN ONCOGENESIS. BETTER UNDERSTANDING OF HEPATITIS B PATHOGENESIS IS MANDATORY FOR IMPROVING DISEASE MANAGEMENT. 2012 20 3251 27 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