1 2792 111 FAT10 IS AN EPIGENETIC MARKER FOR LIVER PRENEOPLASIA IN A DRUG-PRIMED MOUSE MODEL OF TUMORIGENESIS. THERE IS CLINICAL EVIDENCE THAT CHRONIC LIVER DISEASES IN WHICH MDBS (MALLORY DENK BODIES) FORM PROGRESS TO HEPATOCELLULAR CARCINOMA. THE PRESENT STUDY PROVIDES EVIDENCE THAT LINKS MDB FORMATION INDUCED BY CHRONIC DRUG INJURY, WITH PRENEOPLASIA AND LATER TO THE FORMATION OF TUMORS, WHICH DEVELOP LONG AFTER DRUG WITHDRAWAL. EVIDENCE INDICATED THAT THIS LINK WAS DUE TO AN EPIGENETIC CELLULAR MEMORY INDUCED BY CHRONIC DRUG INGESTION. MICROARRAY ANALYSIS SHOWED THAT THE EXPRESSIONS OF MANY MARKERS OF PRENEOPLASIA (UBD, ALPHA FETOPROTEIN, KLF6 AND GLUTATHIONE-S-TRANSFERASE MU2) WERE INCREASED TOGETHER WHEN THE DRUG DDC WAS REFED. THESE CHANGES WERE SUPPRESSED BY S-ADENOSYLMETHIONINE FEEDING, INDICATING THAT THE DRUG WAS AFFECTING DNA AND HISTONES METHYLATION IN AN EPIGENETIC MANNER. THE LINK BETWEEN MDB FORMATION AND NEOPLASIA FORMATION WAS LIKELY DUE TO THE OVER EXPRESSION OF UBD (ALSO CALLED FAT10), WHICH IS UP REGULATED IN 90% OF HUMAN HEPATOCELLULAR CARCINOMAS. IMMUNOHISTOCHEMICAL STAINING OF DRUG-PRIMED MOUSE LIVERS SHOWED THAT FAT10 POSITIVE LIVER CELLS PERSISTED UP TO 4 MONTHS AFTER DRUG WITHDRAWAL AND THEY WERE STILL FOUND IN THE LIVERS OF MICE, 14 MONTHS AFTER DRUG WITHDRAWAL. THE REFEEDING OF DDC INCREASED THE PERCENT OF FAT10 HEPATOCYTES. 2008 2 6361 59 THE ROLE OF INNATE IMMUNITY IN THE PATHOGENESIS OF PRENEOPLASIA IN DRUG-INDUCED CHRONIC HEPATITIS BASED ON A MOUSE MODEL. INNATE IMMUNITY FACTORS SUCH AS CONVERSION OF THE 26S PROTEASOME TO FORM THE IMMUNOPROTEASOME AND THE TOLL-LIKE RECEPTOR SIGNALING PATHWAYS ARE ACTIVATED IN CHRONIC HEPATITIS INDUCED BY THE CARCINOGENIC DRUG DDC. OVER TIME, PRENEOPLASTIC HEPATOCYTE PHENOTYPES APPEAR IN THE LIVER PARENCHYMA. THESE CHANGED HEPATOCYTES EXPAND IN NUMBER BECAUSE THEY HAVE A GROWTH ADVANTAGE OVER NORMAL HEPATOCYTES WHEN RESPONDING TO CHRONIC LIVER INJURY. THE CHANGED HEPATOCYTES CAN BE IDENTIFIED USING IMMUNOFLUORESCENT ANTIBODIES TO PRENEOPLASTIC CELLS E.G. FAT10/UBD, A2 MACROGLOBULIN, GLUTATHIONE TRANSPEPTIDASE, ALPHA FETOPROTEIN, GLYCIPAN 3, FAS, AND GAMMA GLUTAMYL TRANSPEPTIDASE. THE FORMATION OF THE PRENEOPLASTIC CELLS OCCURS CONCOMITANT WITH ACTIVATION OF THE TOLL-LIKE RECEPTOR SIGNALING PATHWAYS AND THE TRANSFORMATION OF THE 26S PROTEASOME TO FORM THE IMMUNOPROTEASOME. THIS TRANSFORMATION IS IN RESPONSE TO INTERFERON STIMULATING RESPONSE ELEMENT ON THE PROMOTER OF THE FAT10/UBD GENE. NFKAPPAB, ERK, P38 AND JNK ARE ALSO UP REGULATED. SPECIFIC INHIBITORS BLOCK THESE RESPONSES IN VITRO IN A MOUSE TUMOR CELL LINE EXPOSED TO INTERFERON GAMMA. MALLORY-DENK BODIES FORM IN THESE PRENEOPLASTIC CELLS, BECAUSE OF THE DEPLETION OF THE 26S PROTEASOME DUE TO FORMATION OF THE IMMUNOPROTEASOME. THUS, MDB FORMING CELLS ARE ALSO MARKERS OF THE PRENEOPLASTIC HEPATOCYTES. THE UBD POSITIVE PRENEOPLASTIC CELLS REGRESS WHEN THE LIVER INJURY INDUCED CHRONIC HEPATITIS SUBSIDES. WHEN THE DRUG DDC IS REFED TO MICE AND CHRONIC HEPATITIS IS ACTIVATED, THE PRENEOPLASTIC CELL POPULATION EXPANDS AND MALLORY-DENK BODIES RAPIDLY REFORM. THIS RESPONSE IS REMEMBERED BY THE PRENEOPLASTIC CELLS FOR AT LEAST FOUR MONTHS INDICATING THAT AN EPIGENETIC CELLULAR MEMORY HAS FORMED IN THE PRENEOPLASTIC CELLS. THIS PROLIFERATIVE RESPONSE IS PREVENTED BY FEEDING METHYL DONORS SUCH AS S-ADENOSYLMETHIONINE OR BETAINE. DRUG FEEDING REDUCES THE METHYLATION OF H(3) K4, 9, AND 27 AND THIS RESPONSE IS PREVENTED BY FEEDING THE METHYL DONORS. AFTER 8 TO 15MONTHS OF DRUG WITHDRAWAL IN MICE THE PRENEOPLASTIC LIVER CELLS PERSIST AS SINGLE OR SMALL CLUSTERS OF CELLS IN THE LIVER LOBULES. MULTIPLE LIVER TUMORS FORM, SOME OF WHICH ARE HEPATOCELLULAR CARCINOMAS. THE TUMORS IMMUNOSTAIN POSITIVELY FOR THE SAME PRENEOPLASTIC MARKERS AS THE PRENEOPLASTIC CELLS. SIMILAR CELLS ARE IDENTIFIED IN HUMAN CIRRHOSIS AND HEPATOCELLULAR CARCINOMA INDICATING THE RELEVANCE OF THE DRUG MODEL DESCRIBED HERE TO THE PRENEOPLASTIC CHANGES ASSOCIATED WITH HUMAN CHRONIC HEPATITIS AND HEPATOCELLULAR CARCINOMA. 2011 3 6310 56 THE REGULATION OF NON-CODING RNA EXPRESSION IN THE LIVER OF MICE FED DDC. MALLORY-DENK BODIES (MDBS) ARE FOUND IN THE LIVER OF PATIENTS WITH ALCOHOLIC AND CHRONIC NONALCOHOLIC LIVER DISEASE, AND HEPATOCELLULAR CARCINOMA (HCC). DIETHYL 1,4-DIHYDRO-2,4,6,-TRIMETHYL-3,5-PYRIDINEDICARBOXYLATE (DDC) IS USED AS A MODEL TO INDUCE THE FORMATION OF MDBS IN MOUSE LIVER. PREVIOUS STUDIES IN THIS LABORATORY SHOWED THAT DDC INDUCED EPIGENETIC MODIFICATIONS IN DNA AND HISTONES. THE COMBINATION OF THESE MODIFICATIONS CHANGES THE PHENOTYPE OF THE MDB FORMING HEPATOCYTES, AS INDICATED BY THE MARKER FAT10. THESE EPIGENETIC MODIFICATIONS ARE PARTIALLY PREVENTED BY ADDING TO THE DIET S-ADENOSYLMETHIONINE (SAME) OR BETAINE, BOTH METHYL DONORS. THE EXPRESSION OF THREE IMPRINTED NCRNA GENES WAS FOUND TO CHANGE IN MDB FORMING HEPATOCYTES, WHICH IS THE SUBJECT OF THIS REPORT. NCRNA EXPRESSION WAS QUANTITATED BY REAL-TIME PCR AND RNA FISH IN LIVER SECTIONS. MICROARRAY ANALYSIS SHOWED THAT THE EXPRESSION OF THREE NCRNAS WAS REGULATED BY DDC: UP REGULATION OF H19, ANTISENSE IGF2R (AIR), AND DOWN REGULATION OF GTL2 (ALSO CALLED MEG3). S-ADENOSYLMETHIONINE (SAME) FEEDING PREVENTED THESE CHANGES. BETAINE, ANOTHER METHYL GROUP DONOR, PREVENTED ONLY H19 AND AIR UP REGULATION INDUCED BY DDC, ON MICROARRAYS. THE RESULTS OF THE SAME AND BETAINE GROUPS WERE CONFIRMED BY REAL-TIME PCR, EXCEPT FOR AIR EXPRESSION. AFTER 1 MONTH OF DRUG WITHDRAWAL, THE EXPRESSION OF THE THREE NCRNAS TENDED TOWARD CONTROL LEVELS OF EXPRESSION. LIVER TUMORS THAT DEVELOPED ALSO SHOWED UP REGULATION OF H19 AND AIR. THE RNA FISH APPROACH SHOWED THAT THE MDB FORMING CELLS' PHENOTYPE CHANGED THE LEVEL OF EXPRESSION OF AIR, H19 AND GTL2, COMPARED TO THE SURROUNDING CELLS. FURTHERMORE, OVER EXPRESSION OF H19 AND AIR WAS DEMONSTRATED IN TUMORS FORMED IN MICE WITHDRAWN FOR 9 MONTHS. THE DYSREGULATION OF NCRNA IN MDB FORMING LIVER CELLS HAS BEEN OBSERVED FOR THE FIRST TIME IN DRUG-PRIMED MICE ASSOCIATED WITH LIVER PRENEOPLASTIC FOCI AND TUMORS. 2009 4 2258 27 EPIGENETIC PRIMING IN CHRONIC LIVER DISEASE IMPACTS THE TRANSCRIPTIONAL AND GENETIC LANDSCAPES OF HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMAS (HCCS) USUALLY ARISE FROM CHRONIC LIVER DISEASE (CLD). PRECANCEROUS CELLS IN CHRONICALLY INFLAMED ENVIRONMENTS MAY BE 'EPIGENETICALLY PRIMED', SENSITISING THEM TO ONCOGENIC TRANSFORMATION. WE INVESTIGATED WHETHER EPIGENETIC PRIMING IN CLD MAY AFFECT HCC OUTCOMES BY INFLUENCING THE GENOMIC AND TRANSCRIPTOMIC LANDSCAPES OF HCC. ANALYSIS OF DNA METHYLATION ARRAYS FROM 10 PAIRED CLD-HCC IDENTIFIED 339 SHARED DYSREGULATED CPG SITES AND 18 SHARED DIFFERENTIALLY METHYLATED REGIONS COMPARED WITH HEALTHY LIVERS. THESE REGIONS WERE ASSOCIATED WITH DYSREGULATED EXPRESSION OF GENES WITH RELEVANCE IN HCC, INCLUDING UBIQUITIN D (UBD), CYTOCHROME P450 FAMILY 2 SUBFAMILY C MEMBER 19 (CYP2C19) AND O-6-METHYLGUANINE-DNA METHYLTRANSFERASE (MGMT). METHYLATION CHANGES WERE RECAPITULATED IN AN INDEPENDENT COHORT OF NINE PAIRED CLD-HCC. HIGH CLD METHYLATION SCORE, DEFINED USING THE 124 DYSREGULATED CPGS IN CLD AND HCC IN BOTH COHORTS, WAS ASSOCIATED WITH POOR SURVIVAL, INCREASED SOMATIC GENETIC ALTERATIONS AND TP53 MUTATIONS IN TWO INDEPENDENT HCC COHORTS. ONCOGENIC TRANSCRIPTIONAL AND METHYLATION DYSREGULATION IS EVIDENT IN CLD AND COMPOUNDED IN HCC. EPIGENETIC PRIMING IN CLD SCULPTS THE TRANSCRIPTIONAL LANDSCAPE OF HCC AND CREATES AN ENVIRONMENT FAVOURING THE ACQUISITION OF GENETIC ALTERATIONS, SUGGESTING THAT THE EXTENT OF EPIGENETIC PRIMING IN CLD COULD INFLUENCE DISEASE OUTCOME. 2022 5 1617 32 DNA METHYLTRANSFERASE EXPRESSION AND DNA METHYLATION IN HUMAN HEPATOCELLULAR CARCINOMA AND THEIR CLINICOPATHOLOGICAL CORRELATION. ABERRANT DNA METHYLATION ON CPG ISLANDS IS ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS, AND THE METHYLATION PROCESS IS CATALYZED BY DNA METHYLTRANSFERASE (DNMT). WE EVALUATED I) THE MRNA LEVELS OF THREE DNMTS; DNMT1, DNMT3A AND DNMT3B, IN 25 HEPATOCELLULAR CARCINOMAS (HCCS), IN THEIR CORRESPONDING NON-CANCEROUS LIVER TISSUES AND IN 7 NORMAL LIVERS BY USING REAL-TIME REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION; II) NUCLEAR EXPRESSION OF DNMT1 AND DNMT3A PROTEINS IN THE HCCS BY IMMUNOHISTOCHEMISTRY, III) THE METHYLATION STATUS OF 5 GENES; P16, P15, E-CADHERIN, HIC-1 AND RASSF1A IN THE SAME TISSUES, AND IV) THE RELATIONSHIPS BETWEEN THE ABOVE RESULTS AND THE CLINICOPATHOLOGICAL CHARACTERISTICS, INCLUDING PROGNOSIS. THE DIFFERENCES IN MRNA EXPRESSION LEVELS FOR DNMT1, DNMT3A AND DNMT3B WERE STATISTICALLY SIGNIFICANT BETWEEN HCC AND NORMAL LIVERS (P<0.001), HCC AND CHRONIC HEPATITIS (P<0.001) AND HCC AND CIRRHOSIS (P<0.001). AN INCREASE IN MRNA EXPRESSION LEVELS OF >4-FOLD FOR DNMT3B IN HCCS WAS SIGNIFICANTLY ASSOCIATED WITH A POORER OVERALL SURVIVAL (P=0.027) AND SHORTER METASTASIS-FREE SURVIVAL (P=0.0299). A POORER RECURRENCE-FREE SURVIVAL WAS NOTED IN HCCS WITH A >4-FOLD INCREASE IN DNMT3A MRNA (P=0.0120). THE AVERAGE NUMBERS OF METHYLATED GENES WERE 0, 1.27, 1.38 AND 2.72 FOR NORMAL LIVERS, CHRONIC HEPATITIS, CIRRHOSIS AND HCCS, RESPECTIVELY, AND THIS PROGRESSIVE INCREASE FROM NORMAL LIVERS TO CHRONIC HEPATITIS/CIRRHOSIS THROUGH HCC MAY SUGGEST THAT TUMOR SUPPRESSOR GENE METHYLATION IS AN EARLY EVENT IN HEPATOCARCINOGENESIS. THESE RESULTS FIRST SUGGEST THAT HEPATOCARCINOGENESIS INVOLVES AN INCREASED EXPRESSION OF DNMT1, DNMT3A AND DNMT3B MRNA AND A PROGRESSIVE INCREASE IN THE NUMBER OF METHYLATED GENES FROM NORMAL LIVER, CHRONIC HEPATITIS/CIRRHOSIS TO HCC AND SECONDLY THAT AN INCREASE IN THE DNMT3A AND DNMT3B MRNA LEVELS IN HCCS RELATIVE TO THEIR NON-CANCEROUS TISSUES MAY BE A PREDICTOR OF POOR SURVIVAL. 2007 6 4903 19 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 2842 28 FREQUENT CONCOMITANT EPIGENETIC SILENCING OF SOX1 AND SECRETED FRIZZLED-RELATED PROTEINS (SFRPS) IN HUMAN HEPATOCELLULAR CARCINOMA. BACKGROUND AND AIM: EXCEPT FOR GENETIC MUTATIONS, EPIGENETIC CHANGES ARE ALSO INVOLVED IN THE DEVELOPMENT OF HUMAN CANCERS. RECENTLY, WE HAVE IDENTIFIED SOX1, SRY (SEX DETERMINING REGION Y)-BOX 1, IS HYPERMETHYLATED IN CERVICAL CANCER AND OVARIAN CANCER. THEREFORE, WE INVESTIGATED WHETHER PROMOTER HYPERMETHYLATION OF SOX1 IS COMMON IN HEPATOCELLULAR CARCINOMA (HCC). METHODS: WE USED METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MS-PCR) AND BISULFITE SEQUENCING TO ANALYZE THE METHYALTION LEVEL OF THE SOX1 PROMOTER IN SEVEN HCC CELL LINES, 54 CLINICAL HCCS, 42 CIRRHOTIC LIVERS, 21 LIVERS WITH CHRONIC HEPATITIS, AND 15 CONTROL LIVERS. THEN, WE EMPLOYED QUANTITATIVE MS-PCR (QMSP) TO VALIDATE IN AN INDEPENDENT SET OF SAMPLES (60 PAIRED HCCS AND 30 CONTROL LIVERS). FINALLY, WE USED LUCIFERASE REPORTER AND COLONY FORMATION ASSAY TO CHECK THE EFFECT OF SOX1 IN HCC. RESULTS: PROMOTER METHYLATION OF SOX1 WAS SIGNIFICANTLY FREQUENT IN HCC CELL LINES AND CLINICAL HCCS, CIRRHOTIC LIVERS, BUT NOT IN CONTROL LIVERS (P < 0.0001). THERE IS A SIGNIFICANT CORRELATION BETWEEN DOWNREGULATION OF SOX1 EXPRESSION AND PROMOTER METHYLATION. QMSP RESULTS CONFIRMED THAT PROMOTER HYPERMETHYLATION OF SOX1 IS SIGNIFICANTLY MORE FREQUENT IN HCCS THAN CONTROL LIVERS (P < 0.0001). THE FREQUENCY OF SOX1 METHYLATION IN PATIENTS WITH SECRETED FRIZZLED-RELATED PROTEINS (SFRPS) METHYLATION IS SIGNIFICANTLY HIGHER THAN IN PATIENTS WITHOUT SFRPS METHYLATION (P < 0.0001). FURTHERMORE, ECTOPIC EXPRESSION OF SOX1 COULD SUPPRESS T-CELL FACTOR-DEPENDENT TRANSCRIPTIONAL ACTIVITY AND COLONY FORMATION NUMBER IN HCCS. CONCLUSIONS: CONCOMITANT EPIGENETIC SILENCING OF SOX1 AND SFRPS THROUGH PROMOTER HYPERMETHYLATION IS FREQUENT IN HCCS, AND THIS MIGHT CONTRIBUTE TO ABNORMAL ACTIVATION OF CANONICAL WNT SIGNAL PATHWAY. 2013 8 3190 31 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 9 3264 34 HEPATITIS VIRUS INFECTION AFFECTS DNA METHYLATION IN MICE WITH HUMANIZED LIVERS. BACKGROUND & AIMS: CELLS OF TUMORS ASSOCIATED WITH CHRONIC INFLAMMATION FREQUENTLY HAVE ALTERED PATTERNS OF DNA METHYLATION, INCLUDING HEPATOCELLULAR CARCINOMAS. CHRONIC HEPATITIS HAS ALSO BEEN ASSOCIATED WITH ABERRANT DNA METHYLATION, BUT LITTLE IS KNOWN ABOUT THEIR RELATIONSHIP. METHODS: PYROSEQUENCING WAS USED TO DETERMINE THE METHYLATION STATUS OF CULTURED HUH7.5.1 HEPATOMA CELLS AFTER HEPATITIS C VIRUS (HCV) INFECTION. WE ALSO STUDIED MICE WITH SEVERE COMBINED IMMUNODEFICIENCY CARRYING THE UROKINASE-TYPE PLASMINOGEN ACTIVATOR TRANSGENE CONTROLLED BY AN ALBUMIN PROMOTER (UROKINASE-TYPE PLASMINOGEN ACTIVATOR/SEVERE COMBINED IMMUNODEFICIENT MICE), IN WHICH UP TO 85% OF HEPATOCYTES WERE REPLACED BY HUMAN HEPATOCYTES (CHIMERIC MICE). MICE WERE GIVEN INTRAVENOUS INJECTIONS OF HEPATITIS B VIRUS (HBV) OR HCV, LIVER TISSUES WERE COLLECTED, AND DNA METHYLATION PROFILES WERE DETERMINED AT DIFFERENT TIME POINTS AFTER INFECTION. WE ALSO COMPARED METHYLATION PATTERNS BETWEEN PAIRED SAMPLES OF HEPATOCELLULAR CARCINOMAS AND ADJACENT NONTUMOR LIVER TISSUES FROM PATIENTS. RESULTS: NO REPRODUCIBLE CHANGES IN DNA METHYLATION WERE OBSERVED AFTER INFECTION OF HUH7.5.1 CELLS WITH HCV. LIVERS FROM HBV- AND HCV-INFECTED MICE HAD GENOME-WIDE, TIME-DEPENDENT CHANGES IN DNA METHYLATION, COMPARED WITH UNINFECTED UROKINASE-TYPE PLASMINOGEN ACTIVATOR/SEVERE COMBINED IMMUNODEFICIENT MICE. THERE WERE CHANGES IN 160 +/- 63 GENES IN HBV-INFECTED AND 237 +/- 110 GENES IN HCV-INFECTED MICE. METHYLATION OF 149 COMMON GENES INCREASED IN HBV- AND HCV-INFECTED MICE; METHYLATION OF SOME OF THESE GENES ALSO INCREASED IN HEPATOCELLULAR CARCINOMA SAMPLES FROM PATIENTS COMPARED WITH NONTUMOR TISSUES. EXPRESSION OF IFNG, WHICH IS EXPRESSED BY NATURAL KILLER CELLS, INCREASED SIGNIFICANTLY IN CHIMERIC LIVERS, IN CONCORDANCE WITH INDUCTION OF DNA METHYLATION, AFTER INFECTION WITH HBV OR HCV. INDUCTION OF IFNG WAS REDUCED AFTER ADMINISTRATION OF AN INHIBITOR OF NATURAL KILLER CELL FUNCTION (ANTI-ASIALO GM1). CONCLUSIONS: IN CHIMERIC MICE WITH HUMANIZED LIVERS, INFECTION WITH HBV AND HCV APPEARS TO ACTIVATE A NATURAL KILL CELL-DEPENDENT INNATE IMMUNE RESPONSE. THIS CONTRIBUTES TO THE INDUCTION AND ACCUMULATION OF ABERRANT DNA METHYLATION IN HUMAN HEPATOCYTES. 2014 10 153 35 ABERRANT METHYLATION OF MULTIPLE TUMOR SUPPRESSOR GENES IN AGING LIVER, CHRONIC HEPATITIS, AND HEPATOCELLULAR CARCINOMA. ABERRANT DNA METHYLATION IS AN IMPORTANT EPIGENETIC ALTERATION IN HEPATOCELLULAR CARCINOMA (HCC). HOWEVER, THE MOLECULAR PROCESSES UNDERLYING THE METHYLATOR PHENOTYPE AND THE CONTRIBUTION OF HEPATITIS VIRUSES ARE POORLY UNDERSTOOD. THE CURRENT STUDY IS A COMPREHENSIVE METHYLATION ANALYSIS OF HUMAN LIVER TISSUE SPECIMENS. A TOTAL OF 176 LIVER TISSUES, INCLUDING 77 PAIRS OF HCCS AND MATCHING NONCANCEROUS LIVER AND 22 NORMAL LIVERS, WERE ANALYZED FOR METHYLATION. METHYLATION OF 19 EPIGENETIC MARKERS WAS QUANTIFIED, AND THE RESULTS WERE CORRELATED WITH DIFFERENT DISEASE STATES AND THE PRESENCE OR ABSENCE OF HEPATITIS B VIRUS (HBV) AND HEPATITIS C VIRUS (HCV) INFECTIONS. BASED ON METHYLATION PROFILES, THE 19 LOCI WERE CATEGORIZED INTO 3 GROUPS. NORMAL LIVER TISSUES SHOWED METHYLATION PRIMARILY IN GROUP 1 LOCI (HIC-1, CASP8, GSTP1, SOCS1, RASSF1A, P16, APC), WHICH WAS SIGNIFICANTLY HIGHER THAN GROUP 2 (CDH1, RUNX3, RIZ1, SFRP2, MINT31) AND GROUP 3 MARKERS (COX2, MINT1, CACNA1G, RASSF2, MINT2, REPRIMO, DCC) (P < 0.0001). NONCANCEROUS LIVERS DEMONSTRATED INCREASED METHYLATION IN BOTH GROUP 1 AND GROUP 2 LOCI. METHYLATION WAS SIGNIFICANTLY MORE ABUNDANT IN HCV-POSITIVE LIVERS COMPARED WITH NORMAL LIVER TISSUES. CONVERSELY, HCC SHOWED FREQUENT METHYLATION AT EACH LOCUS INVESTIGATED IN ALL 3 GROUPS. HOWEVER, THE GROUP 3 LOCI SHOWED MORE DENSE AND FREQUENT METHYLATION IN HCV-POSITIVE CANCERS COMPARED WITH BOTH HBV-POSITIVE CANCERS AND VIRUS-NEGATIVE CANCERS (P < 0.0001). CONCLUSION: METHYLATION IN HCC IS FREQUENT BUT OCCURS IN A GENE-SPECIFIC AND DISEASE-SPECIFIC MANNER. METHYLATION PROFILING ALLOWED US TO DETERMINE THAT ABERRANT METHYLATION IS COMMONLY PRESENT IN NORMAL AGING LIVERS, AND SEQUENTIALLY PROGRESSES WITH ADVANCING STAGES OF CHRONIC VIRAL INFECTION. FINALLY, OUR DATA PROVIDE EVIDENCE THAT HCV INFECTION MAY ACCELERATE THE METHYLATION PROCESS AND SUGGESTS A CONTINUUM OF INCREASING METHYLATION WITH PERSISTENT VIRAL INFECTION AND CARCINOGENESIS IN THE LIVER. 2008 11 1646 31 DOES THE HEPATITIS B ANTIGEN HBX PROMOTE THE APPEARANCE OF LIVER CANCER STEM CELLS? HEPATITIS B VIRUS (HBV) IS A MAJOR ETIOLOGIC AGENT OF CHRONIC LIVER DISEASE AND HEPATOCELLULAR CARCINOMA (HCC). HBV-ENCODED X ANTIGEN, HBX, AND PATHWAYS IMPLICATED IN THE SELF-RENEWAL OF STEM CELLS CONTRIBUTE TO HCC, BUT IT IS NOT CLEAR WHETHER HBX EXPRESSION PROMOTES "STEMNESS." THUS, EXPERIMENTS WERE DESIGNED TO TEST THE HYPOTHESIS THAT HBX TRIGGERS MALIGNANT TRANSFORMATION BY PROMOTING PROPERTIES THAT ARE CHARACTERISTIC OF CANCER STEM CELLS (CSC). TO TEST THIS HYPOTHESIS, HEPG2 CELLS WERE STABLY TRANSDUCED WITH HBX AND THEN ASSAYED FOR PHENOTYPIC AND MOLECULAR CHARACTERISTICS OF "STEMNESS." THE RELATIONSHIP BETWEEN HBX AND "STEMNESS"-ASSOCIATED MARKERS WAS ALSO EVALUATED BY IMMUNOHISTOCHEMICAL STAINING OF LIVER AND TUMOR TISSUE SECTIONS FROM HBV-INFECTED PATIENTS. THE RESULTS SHOWED THAT OCT-4, NANOG, KLF-4, BETA-CATENIN, AND EPITHELIAL CELL ADHESION MOLECULE (EPCAM) WERE ACTIVATED BY HBX IN VITRO AND IN VIVO. EPCAM WAS DETECTED IN THE NUCLEI OF HUMAN HCC CELLS FROM INFECTED PATIENTS. HBX PROMOTES "STEMNESS" BY ACTIVATING BETA-CATENIN AND EPIGENETIC UPREGULATION OF MIR-181, BOTH OF WHICH TARGET EPCAM. HBX EXPRESSION WAS ALSO ASSOCIATED WITH DEPRESSED LEVELS OF E-CADHERIN. MOREOVER, HBX STIMULATED CELL MIGRATION, GROWTH IN SOFT AGAR, AND SPHEROID FORMATION. THIS WORK IS THE FIRST TO PROPOSE THAT HBV PROMOTES "STEMNESS" IN THE PATHOGENESIS OF HCC. HBX-ASSOCIATED UPREGULATED EXPRESSION OF MULTIPLE "STEMNESS" MARKERS SUPPORTS THE HYPOTHESIS THAT HBX CONTRIBUTES TO HEPATOCARCINOGENESIS, AT LEAST IN PART, BY PROMOTING CHANGES IN GENE EXPRESSION THAT ARE CHARACTERISTICS OF CSCS. 2011 12 6770 27 [ABERRANT METHYLATION OF MULTIPLE GENES AND ITS CLINICAL IMPLICATION IN HEPATOCELLULAR CARCINOMA]. OBJECTIVE: TO INVESTIGATE THE METHYLATION FREQUENCIES OF MULTIPLE TUMOR SUPPRESSOR GENES (TSGS) IN HEPATOCELLULAR CARCINOMA (HCC) AND THE CLINICAL IMPLICATION OF ABERRANT DNA METHYLATION IN MOLECULAR CARCINOGENESIS OF HCC. METHODS: SIXTY SAMPLES OF HCC AND THE PAIRED ADJACENT LIVER TISSUE, 16 SAMPLES FROM POST-HEPATITIS CIRRHOTIC LIVERS, 5 FROM LIVERS WITH CHRONIC HEPATITIS AND 5 FROM NORMAL LIVERS WERE COLLECTED. EIGHT TSGS FREQUENTLY SILENCED BY HYPERMETHYLATION OF THEIR PROMOTERS IN VARIOUS TYPES OF DIGESTIVE TUMORS WERE SELECTED, INCLUDING APC, RASSF1A, P16, GSTP1, MGMT, DAPK, SOCS-1 AND RIZ1. THE STATUS OF PROMOTER METHYLATION IN THESE 8 GENES WAS INVESTIGATED USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. THE CLINICOPATHOLOGICAL DATA OF HCC WERE ALSO ANALYZED IN ORDER TO EVALUATE THE CLINICAL IMPLICATION OF ABERRANT METHYLATION IN HCC. RESULTS: METHYLATION OF THE 8 TSGS WAS QUITE FREQUENT IN HCC, WITH A METHYLATION RATE OF 95.0% IN RASSF1A, 90.0% IN APC, 73.3% IN GSTP1, 65.0% IN P16, 61.6% IN RIZ1 AND 60.0% IN MGMT. METHYLATION OF THE 6 GENES WAS MORE FREQUENT IN HCC THAN THAT IN ADJACENT TISSUES (P < 0.05). THE METHYLATION RATE OF MGMT, GSTP1 AND RIZ1 IN THE ADJACENT TISSUES WAS 41.6%, 40.0% AND 25.0%, RESPECTIVELY, SIGNIFICANTLY HIGHER THAN THAT IN CIRRHOTIC LIVER (P < 0.05). P16 METHYLATION WAS MORE FREQUENTLY OBSERVED IN HCC IN ELDERLY PATIENTS. THE FREQUENCY OF MGMT METHYLATION WAS TENDED TO BE HIGHER IN GIANT HCC THAN THAT IN THE OTHER TYPES OF HCC. PATIENTS WITH MGMT METHYLATION IN THE TUMOR WERE FOUND TO HAVE A SHORTER DISEASE FREE SURVIVAL. CONCLUSION: DIFFERENT FREQUENCY OF METHYLATION IN HEPATOCELLULAR CARCINOMAS, ADJACENT LIVER TISSUES AND CIRRHOTIC LIVERS IMPLIES THAT EPIGENETIC ALTERATION IN THE HEPATOCELLULAR CARCINOGENESIS MAY BE A GRADUALLY PROGRESSIVE PROCESS. METHYLATION STATUS OF MGMT, GSTP1 AND RIZ1 MAY BE PROMISING IN RISK ASSESSMENT OF HEPATOCELLULAR CARCINOMA AND IN EARLY DIAGNOSIS. FURTHERMORE, MGMT METHYLATION MIGHT BE ALSO USED AS A POTENTIAL PROGNOSTIC BIOMARKER FOR HEPATOCELLULAR CARCINOMA PATIENTS. 2008 13 6692 31 VARIABLE DNA METHYLATION PATTERNS ASSOCIATED WITH PROGRESSION OF DISEASE IN HEPATOCELLULAR CARCINOMAS. HEPATOCELLULAR CARCINOMA (HCC) MOST COMMONLY ARISES FROM CHRONIC INFLAMMATION DUE TO VIRAL INFECTION, AS A RESULT OF GENETIC AND EPIGENETIC ABNORMALITIES. A GLOBAL PICTURE OF EPIGENETIC CHANGES IN HCC IS LACKING. WE USED METHYLATED CPG ISLAND AMPLIFICATION MICROARRAYS (MCAMS) TO STUDY 6458 CPG ISLANDS IN HCC AND ADJACENT PRENEOPLASTIC TISSUES [CHRONIC HEPATITIS (CH) OR LIVER CIRRHOSIS (LC)] IN COMPARISON WITH NORMAL LIVER TISSUES WHERE NEITHER VIRAL INFECTION NOR HEPATITIS HAS EXISTED. MCAM IDENTIFIED 719 (11%) PROMINENT GENES OF HYPERMETHYLATION IN HCCS. HCCS ARISING FROM LC HAD SIGNIFICANTLY MORE METHYLATION THAN THOSE ARISING FROM CH (1249 GENES OR 19% VERSUS 444 GENES OR 7%, P < 0.05). THERE WERE FOUR PATTERNS OF ABERRANT METHYLATION: TYPE I (4%, E.G. MATRIX METALLOPROTEINASE 14) SHOWS A SUBSTANTIALLY HIGH METHYLATION LEVEL IN ADJACENT TISSUE AND DOES NOT INCREASE FURTHER IN CANCER. TYPE II (55%, E.G. RASSF1A) SHOWS PROGRESSIVELY INCREASING METHYLATION FROM ADJACENT TISSUE TO HCC. TYPE III (4%, E.G. GNA14) SHOWS DECREASED METHYLATION IN ADJACENT TISSUE BUT EITHER SIMILAR OR INCREASED METHYLATION IN HCC. TYPE IV (37%, E.G. CDKN2A) SHOWS LOW LEVELS OF METHYLATION IN NORMAL TISSUE AND ADJACENT TISSUE BUT HIGH LEVELS IN HCC. THESE DNA METHYLATION CHANGES WERE CONFIRMED BY QUANTITATIVE PYROSEQUENCING METHYLATION ANALYSIS IN REPRESENTATIVE 24 GENES AND WERE ANALYZED FOR CORRELATION WITH CLINICOPATHOLOGICAL PARAMETERS IN 38 PATIENTS. INTRIGUINGLY, METHYLATION IN THE TYPE IV GENES IS CHARACTERISTIC OF MODERATELY/POORLY DIFFERENTIATED CANCER. OUR GLOBAL EPIGENOME ANALYSIS REVEALS DISTINCT PATTERNS OF METHYLATION THAT ARE PROBABLY TO REPRESENT DIFFERENT PATHOPHYSIOLOGIC PROCESSES IN HCCS. 2008 14 6848 28 [MOLECULAR GENETIC AND EPIGENETIC MECHANISMS OF HEPATOCARCINOGENESIS]. HEPATOCELLULAR CARCINOMA (HCC) IS A MAJOR TYPE OF PRIMARY LIVER CANCER AND ONE OF THE MOST FREQUENT HUMAN MALIGNANT NEOPLASMS. COMMON RISK FACTORS OF HUMAN HCC INCLUDE CHRONIC HEPATITIS VIRUS (HBV AND HCV) INFECTION, DIETARY AFLATOXIN B1 (AFB1) INGESTION, CHRONIC ALCOHOL ABUSE, AND CIRRHOSIS ASSOCIATED WITH GENETIC LIVER DISEASES. HEPATOCARCINOGENESIS IS THE RESULT OF INTERACTION BETWEEN HEREDITARY AND ENVIRONMENTAL FACTORS. INHERITANCE DETERMINES INDIVIDUAL SUSCEPTIBILITY TO CANCER; ENVIRONMENT DETERMINES WHICH SUSCEPTIBLE INDIVIDUALS EXPRESS CANCER. STUDIES OF GENETIC AND EPIGENETIC MECHANISMS OF HEPATOCARCINOGENESIS SHOWED THAT HCC DEVELOPMENT IS A COMPLEX POLYGENE AND MULTIPATHWAY PROCESS; THE ACTIVATION OF PROTO-ONCOGENES AND THE INACTIVATION OF TUMOR SUPPRESSOR GENES INDUCED BY GENETIC AND EPIGENETIC ALTERATIONS ARE CORE BIOLOGICAL PROCESSES OF HEPATOCARCINOGENESIS; RB1, P53, AND WNT PATHWAYS ARE COMMONLY AFFECTED IN HCCS OF DIFFERENT ETIOLOGIES, WHICH MAY REFLECT COMMON PATHOLOGIC SEQUENCE OF HCC: CHRONIC LIVER INJURY, CIRRHOSIS, ATYPICAL HYPERPLASTIC NODULES, AND HCC OF EARLY STAGES. HEPATITIS VIRUS INFECTION-ASSOCIATED HCCS HAVE FREQUENT ALTERATIONS IN RB1 PATHWAY, INCLUDING METHYLATION OF P16INK4A AND RB1 GENES AND AMPLIFICATION OF CYCLIN D1. AFB1 EXPOSURE-ASSOCIATED HCCS HAVE FREQUENT ALTERATIONS IN P53 PATHWAY; THE G-->T MUTATION OF P53 GENE AT CODON 249 HAS BEEN IDENTIFIED AS A GENETIC HALLMARK OF HCC CAUSED BY AFB1. ALCOHOLISM-ASSOCIATED HCCS HAVE FREQUENT ALTERATIONS IN BOTH RB1 AND P53 PATHWAYS. THE ROLES OF SOME IMPORTANT GENES RELATED TO CELL APOPTOSIS, DNA REPAIR, DRUG METABOLISM, AND TUMOR METASTASIS IN HEPATOCARCINOGENESIS HAD BEEN DISCUSSED. 2005 15 512 31 ASSOCIATION OF SAT-A AND ALU METHYLATION STATUS WITH HCV-INDUCED CHRONIC LIVER DISEASE AND HEPATOCELLULAR CARCINOMA. BACKGROUND: THE COMBINATION OF EPIGENETIC AND GENETIC ABNORMALITIES CONTRIBUTES TOGETHER TO THE DEVELOPMENT OF LIVER CANCER. THE METHYLATION STATUS OF THE REPETITIVE ELEMENTS (RES) IN DNA HAS BEEN INVESTIGATED IN A VARIETY OF HUMAN ILLNESSES. HOWEVER, THE METHYLATION PATTERNS OF SAT-ALPHA AND ALU RES IN CHRONIC LIVER DISEASE (CLD) AND HEPATOCELLULAR CARCINOMA (HCC) CAUSED BY HEPATITIS C VIRUS (HCV) HAVE NEVER BEEN STUDIED BEFORE. METHODOLOGY: IN THIS STUDY, 3 GROUPS OF PARTICIPANTS INCLUDING 50 PATIENTS HAVING HCV-INDUCED CLD, 50 PATIENTS HAVING HCV-INDUCED HCC, AND 46 HEALTHY SUBJECTS WERE SUBJECTED TO MEASUREMENT OF SAT-ALPHA AND ALU METHYLATION USING THE QUANTITATIVE METHYLIGHT ASSAY. RESULTS: SAT-ALPHA AND ALU METHYLATION PERCENTAGES DECREASED SIGNIFICANTLY IN BOTH CLD AND HCC, COMPARED TO CONTROL. ALSO, A SIGNIFICANT SAT-ALPHA HYPOMETHYLATION WAS DETECTED IN HCC, COMPARED TO CLD. IN ADDITION, SAT-ALPHA AND ALU METHYLATION SHOWED A SIGNIFICANT DECLINE AS LESION SIZE GREW. HOWEVER, ONLY SAT-ALPHA HYPOMETHYLATION WAS SIGNIFICANTLY INCREASED IN ASSOCIATION WITH PORTAL VEIN THROMBOSIS AND THE MELD SCORE. SAT-ALPHA METHYLATION PERCENTAGE HAD THE HIGHEST SENSITIVITY AND SPECIFICITY FOR DIAGNOSING HCC (100% AND 84.4%) FOLLOWED BY ALPHA-FETOPROTEIN (80% AND 84.4%) AND ALU METHYLATION (66% AND 61.5%). FURTHERMORE, THERE WAS A STRONG POSITIVE CORRELATION BETWEEN SAT-ALPHA AND ALU METHYLATION. CONCLUSIONS: MEASURING SAT-ALPHA AND ALU METHYLATION PROVIDES US WITH A NEW TOOL FOR EARLY DETECTING HCV-INDUCED CLD AND HEPATOCARCINOGENESIS. SAT-ALPHA HAS THE POTENTIAL TO BE UTILIZED AS AN INDEPENDENT PREDICTIVE PARAMETER FOR HCC DEVELOPMENT AND PROGRESSION BECAUSE OF ITS ABILITY TO DISTINGUISH BETWEEN CLD AND HCC WITH THEIR DIFFERENT MELD SCORES. 2022 16 824 30 CHARACTERIZATION OF COPY NUMBER ALTERATIONS IN A MOUSE MODEL OF FIBROSIS-ASSOCIATED HEPATOCELLULAR CARCINOMA REVEALS CONCORDANCE WITH HUMAN DISEASE. HEPATOCELLULAR CARCINOMA (HCC) IS A PREVALENT HUMAN CANCER WITH RISING INCIDENCE WORLDWIDE. HUMAN HCC IS FREQUENTLY ASSOCIATED WITH CHRONIC LIVER INFLAMMATION AND CIRRHOSIS, PATHOPHYSIOLOGICAL PROCESSES THAT ARE A CONSEQUENCE OF CHRONIC VIRAL INFECTION, DISTURBANCES IN METABOLISM, OR EXPOSURE TO CHEMICAL TOXICANTS. TO BETTER CHARACTERIZE THE PATHOGENESIS OF HCC, WE USED A HUMAN DISEASE-RELEVANT MOUSE MODEL OF FIBROSIS-ASSOCIATED HEPATOCARCINOGENESIS. IN THIS MODEL, MARKED LIVER TUMOR RESPONSE CAUSED BY THE PROMUTAGENIC CHEMICAL N-NITROSODIETHYLAMINE IN THE PRESENCE OF LIVER FIBROSIS WAS ASSOCIATED WITH EPIGENETIC EVENTS INDICATIVE OF GENOMIC INSTABILITY. THEREFORE, WE HYPOTHESIZED THAT DNA COPY NUMBER ALTERATIONS (CNAS), A FEATURE OF GENOMIC INSTABILITY AND A COMMON CHARACTERISTIC OF CANCER, ARE CONCORDANT BETWEEN HUMAN HCC AND MOUSE MODELS OF FIBROSIS-ASSOCIATED HEPATOCARCINOGENESIS. WE EVALUATED DNA CNAS AND CHANGES IN GENE EXPRESSION IN THE MOUSE LIVER (NORMAL, TUMOR, AND NONTUMOR FIBROTIC TISSUES). ADDITIONALLY, WE COMPARED OUR FINDINGS TO DNA CNAS IN HUMAN HCC CASES (TUMOR AND NONTUMOR CIRRHOTIC/FIBROTIC TISSUES) USING PUBLICLY AVAILABLE DATA FROM THE CANCER GENOME ATLAS (TCGA). WE OBSERVED THAT WHILE FIBROTIC LIVER TISSUE IS LARGELY DEVOID OF DNA CNAS, HIGHLY FREQUENTLY OCCURRING DNA CNAS ARE FOUND IN MOUSE TUMORS, WHICH IS INDICATIVE OF A PROFOUND INCREASE IN CHROMOSOMAL INSTABILITY IN HCC. THE CROSS-SPECIES GENE-LEVEL COMPARISON OF CNAS IDENTIFIED SHARED REGIONS OF CNAS BETWEEN HUMAN FIBROSIS- AND CIRRHOSIS-ASSOCIATED LIVER TUMORS AND MOUSE FIBROSIS-ASSOCIATED HCC. OUR RESULTS SUGGEST THAT CNAS MOST COMMONLY ARISE IN NEOPLASTIC TISSUE RATHER THAN IN FIBROTIC OR CIRRHOTIC LIVER, AND DEMONSTRATE THE UTILITY OF THIS MOUSE MODEL IN REPLICATING THE MOLECULAR FEATURES OF HUMAN HCC. 2016 17 5731 26 SMAD3 PHOSPHO-ISOFORM SIGNALING IN HEPATITIS C VIRUS-RELATED CHRONIC LIVER DISEASES. THE RISK OF HEPATOCELLULAR CARCINOMA (HCC) DEVELOPMENT INCREASES AS HEPATITIS VIRUS C (HCV)-RELATED LIVER DISEASES PROGRESS, ESPECIALLY IN PATIENTS WITH ACTIVE INFLAMMATION. INSIGHT INTO HEPATIC CARCINOGENESIS HAVE EMERGED FROM RECENT DETAILED ANALYSES OF TRANSFORMING GROWTH FACTOR-BETA AND C-JUN-N-TERMINAL KINASE SIGNALING PROCESSES DIRECTED BY MULTIPLE PHOSPHORYLATED (PHOSPHO)-ISOFORMS OF A SMAD3 MEDIATOR. IN THE COURSE OF HCV-RELATED CHRONIC LIVER DISEASES, CHRONIC INFLAMMATION AND HOST GENETIC/EPIGENETIC ALTERATIONS ADDITIVELY SHIFT THE HEPATOCYTIC SMAD3 PHOSPHO-ISOFORM SIGNALING FROM TUMOR SUPPRESSION TO CARCINOGENESIS, INCREASING THE RISK OF HCC. CHRONIC INFLAMMATION REPRESENTS AN EARLY CARCINOGENIC STEP THAT PROVIDES A NONMUTAGENIC TUMOR-PROMOTING STIMULUS. AFTER UNDERGOING SUCCESSFUL ANTIVIRAL THERAPY, PATIENTS WITH CHRONIC HEPATITIS C COULD EXPERIENCE A LOWER RISK OF HCC AS SMAD3 PHOSPHO-ISOFORM SIGNALING REVERSES FROM POTENTIAL CARCINOGENESIS TO TUMOR SUPPRESSION. EVEN AFTER HCV CLEARANCE, HOWEVER, PATIENTS WITH CIRRHOSIS COULD STILL DEVELOP HCC BECAUSE OF SUSTAINED, INTENSE CARCINOGENIC SMAD3 PHOSPHO-ISOFORM SIGNALING THAT IS POSSIBLY CAUSED BY GENETIC OR EPIGENETIC ALTERATIONS. SMAD3 PHOSPHO-ISOFORMS SHOULD ASSIST WITH EVALUATING THE EFFECTIVENESS OF INTERVENTIONS AIMED AT REDUCING HUMAN HCC. 2014 18 3646 27 INCREASED PROTEIN EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) 1 IS SIGNIFICANTLY CORRELATED WITH THE MALIGNANT POTENTIAL AND POOR PROGNOSIS OF HUMAN HEPATOCELLULAR CARCINOMAS. ALTERATION OF DNA METHYLATION IS ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS. DNA METHYLTRANSFERASE (DNMT) 1 IS A MAJOR ENZYME INVOLVED IN ESTABLISHING GENOMIC METHYLATION PATTERNS. MOST OF THE STUDIES CONCERNING DNMT1 EXPRESSION IN HUMAN CANCERS HAVE BEEN PERFORMED ONLY AT THE MRNA LEVEL. TO DIRECTLY EXAMINE DNMT1 PROTEIN EXPRESSION LEVELS DURING HUMAN HEPATOCARCINOGENESIS, 16 HISTOLOGICALLY NORMAL LIVER TISSUES, 51 NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS, WHICH ARE CONSIDERED TO BE PRECANCEROUS CONDITIONS, AND 53 HEPATOCELLULAR CARCINOMAS (HCCS) WERE SUBJECTED TO IMMUNOHISTOCHEMIC EXAMINATION. IF MORE THAN 20% OF THE CELLS EXHIBITED NUCLEAR DNMT1 STAINING, THE TISSUE SAMPLE WAS CONSIDERED TO BE DNMT1-POSITIVE. DNMT1 IMMUNOREACTIVITY WAS OBSERVED IN 23 (43%) OF THE HCCS, BUT IN NONE (0%) OF THE HISTOLOGICALLY NORMAL LIVER OR NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS. THE INCIDENCE OF INCREASED DNMT1 PROTEIN EXPRESSION IN HCCS CORRELATED SIGNIFICANTLY WITH POOR TUMOR DIFFERENTIATION (P = 0.0006) AND PORTAL VEIN INVOLVEMENT (P = 0.0002). MOREOVER, THE RECURRENCE-FREE (P = 0.0001) AND OVERALL (P < 0.0001) SURVIVAL RATES OF PATIENTS WITH HCCS EXHIBITING INCREASED DNMT1 PROTEIN EXPRESSION WERE SIGNIFICANTLY LOWER THAN THOSE OF PATIENTS WITH HCCS THAT DID NOT EXHIBIT INCREASED EXPRESSION. INCREASED DNMT1 PROTEIN EXPRESSION MAY PLAY A CRITICAL ROLE IN THE MALIGNANT PROGRESSION OF HCCS AND BE A BIOLOGIC PREDICTOR OF BOTH HCC RECURRENCE AND A POOR PROGNOSIS IN HCC PATIENTS. 2003 19 5057 22 PHENOBARBITAL MECHANISTIC DATA AND RISK ASSESSMENT: ENZYME INDUCTION, ENHANCED CELL PROLIFERATION, AND TUMOR PROMOTION. CHRONIC EXPOSURE TO HIGH DOSES OF PHENOBARBITAL (PB) CAUSES HEPATOCELLULAR ADENOMAS IN BOTH MICE AND RATS AND HEPATOCELLULAR CARCINOMAS IN SOME STRAINS OF MICE. LONG-TERM PB THERAPY HAS NOT BEEN FOUND TO CAUSE HUMAN TUMORS. PB IS NOT DNA REACTIVE, AND MOST GENOTOXICITY TESTS HAVE YIELDED NEGATIVE RESULTS. PB HAS BEEN EXTENSIVELY STUDIED AS AN EPIGENETIC, RODENT LIVER TUMOR PROMOTER. AT EXPOSURES CAUSING RODENT LIVER TUMORS, PB HAS MEASURABLE EFFECTS ON HEPATOCYTES: PB INHIBITS CELL-TO-CELL COMMUNICATION; PB INDUCES ENZYMES, INCLUDING P450 CYTOCHROMES; PB STIMULATES PROLIFERATION AND INHIBITS APOPTOSIS OF HEPATOCYTES IN NEOPLASTIC FOCI. THRESHOLD EXPOSURES FOR SOME OF THESE ENDPOINTS COINCIDE WITH THE THRESHOLD EXPOSURE FOR TUMORIGENESIS. 1996 20 2844 24 FREQUENT EPIGENETIC INACTIVATION OF SFRP GENES IN HEPATOCELLULAR CARCINOMA. BACKGROUND: ACTIVATION OF THE WNT SIGNALING PATHWAY IS FREQUENTLY OBSERVED IN HEPATOCELLULAR CARCINOMA (HCC), THOUGH MUTATION OF THREE OF ITS COMPONENTS, CTNNB1, AXIN1, AND AXIN2, IS OBSERVED SUBSTANTIALLY LESS OFTEN. METHODS: WE EXAMINED THE RELATIONSHIP BETWEEN WNT SIGNALING AND EPIGENETIC ALTERATION OF SECRETED FRIZZLED-RELATED PROTEIN (SFRP) GENES IN HCC. RESULTS: WE FREQUENTLY DETECTED THE ACTIVE FORM OF BETA-CATENIN AND ACCUMULATION OF NUCLEAR BETA-CATENIN IN LIVER CANCER CELL LINES. WE DETECTED METHYLATION OF SFRP FAMILY GENES IN LIVER CANCER CELL LINES (SFRP1, 9/12, 75%; SFRP2, 7/12, 58%; SFRP4, 3/12, 25%; SFRP5, 7/12, 58%) AND PRIMARY HCCS (SFRP1, 9/19, 47%; SFRP2, 12/19, 63%; SFRP5, 8/19, 42%), THOUGH METHYLATION OF SFRP4 WAS NOT FOUND IN PRIMARY HCCS. SFRP METHYLATION ALSO WAS DETECTED IN HEPATITIS B OR C VIRUS-ASSOCIATED CHRONIC HEPATITIS (SFRP1, 6/37, 16%; SFRP2, 14/37, 38%; SFRP5, 5/37, 14%) AND LIVER CIRRHOSIS (SFRP1, 10/28, 36%; SFRP2, 9/28, 32%; SFRP5, 3/28, 11%), SUGGESTING THAT METHYLATION OF THESE GENES IS AN EARLY EVENT IN LIVER CARCINOGENESIS. ECTOPIC EXPRESSION OF SFRPS DOWNREGULATED T-CELL FACTOR/LYMPHOCYTE ENHANCER FACTOR (TCF/LEF) TRANSCRIPTIONAL ACTIVITY IN LIVER CANCER CELLS, WHILE OVEREXPRESSION OF A BETA-CATENIN MUTANT AND DEPLETION OF SFRP1 USING SIRNA SYNERGISTICALLY UPREGULATED TCF/LEF TRANSCRIPTIONAL ACTIVITY. CONCLUSIONS: OUR RESULTS CONFIRM THE FREQUENT METHYLATION AND SILENCING OF WNT ANTAGONIST GENES IN HCC, AND SUGGEST THAT THEIR LOSS OF FUNCTION CONTRIBUTES TO ACTIVATION OF WNT SIGNALING DURING HEPATOCARCINOGENESIS. 2008