1 5057 82 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 2 5487 26 REVERSIBLE ALTERATION IN THE EXPRESSION OF THE GAP JUNCTIONAL PROTEIN CONNEXIN 32 DURING TUMOR PROMOTION IN RAT LIVER AND ITS ROLE DURING CELL PROLIFERATION. ALTHOUGH NUMEROUS BIOCHEMICAL MARKERS CAN IDENTIFY PUTATIVE PRENEOPLASTIC ALTERED HEPATIC FOCI (AHF) IN RAT LIVER, NO CONSISTENT PATTERN OF EXPRESSION DURING HEPATOCARCINOGENESIS HAS EMERGED. USING QUANTITATIVE STEREOLOGIC ANALYSES WE DEMONSTRATED THAT DECREASED EXPRESSION OF THE MAJOR HEPATOCYTE GAP JUNCTION PROTEIN, CONNEXIN 32 (CX32), IN RAT AHF IS A CONSISTENT OBSERVATION IN SEVERAL PROTOCOLS OF MULTISTAGE HEPATOCARCINOGENESIS. THIS CHANGE WAS OBSERVED AFTER INITIATION BY EITHER ETHYLNITROSOUREA (ENU) OR DIETHYLNITROSAMINE (DEN), FOLLOWED BY PROMOTION WITH PHENOBARBITAL (PB), DIOXIN, CHLORENDIC ACID, C.I. SOLVENT YELLOW, OR TAMOXIFEN. AHF GENERATED BY WY-14,643, CIPROFIBRATE, AND A CHOLINE/METHIONINE-DEFICIENT DIETARY REGIMEN ALSO SHOWED DECREASED CX32 EXPRESSION. THE DECREASE OF CX32 IN AHF WAS RAPIDLY REVERSIBLE AFTER WITHDRAWAL OF PB, AND THIS CHANGE PRECEDED A REDUCTION IN PLACENTAL ISOZYME OF GLUTATHIONE-S-TRANSFERASE (GST) EXPRESSION IN THE SAME AHF. WITHIN 20 DAYS OF WITHDRAWAL, FEWER THAN 4% OF GST-POSITIVE AHF WERE CX32 DEFICIENT, WHILE THE VOLUME OF TOTAL AHF DECREASED 30%. CHRONIC PB TREATMENT ALSO RESULTED IN A REVERSIBLE DECREASE IN CX32 SPECIFICALLY IN MID- AND CENTRO-LOBULAR HEPATOCYTES. CONTINUOUS THYMIDINE LABELING DEMONSTRATED THAT CX32 COULD BE UNCOUPLED FROM THE CELL CYCLE, SUGGESTING THAT SOME LIVER PROMOTERS MAY ACT DIRECTLY TO ALTER THE EXPRESSION OF CX32. THESE OBSERVATIONS SUGGEST THAT A DECREASE IN CX32 CONTENT WAS A RELATIVELY COMMON EPIGENETIC CHANGE IN AHF INDUCED DURING HEPATOCARCINOGENESIS BY A NUMBER OF INITIATING AND PROMOTING AGENTS BUT THAT THIS CHANGE WAS NOT SUFFICIENT FOR CARCINOGENESIS. THIS CHANGE, HOWEVER, MAY BE NECESSARY FOR THE MECHANISM(S) OF TUMOR PROMOTION, SINCE CX32-POSITIVE AHF DID NOT PROLIFERATE AS READILY AS CX32-DEFICIENT AHF. 1990 3 1501 13 DNA METHYLATION ANALYSIS OF HUMAN TISSUE-SPECIFIC CONNEXIN GENES. CONNEXINS ARE THE STRUCTURAL PROTEINS OF GAP JUNCTIONS AND THEIR FUNCTIONING AS TUMOR SUPPRESSORS IS WELL KNOWN. EPIGENETIC MODIFICATIONS, SUCH AS METHYLATION OF CONNEXIN GENES, PLAY IMPORTANT ROLES IN REGULATING GENE EXPRESSION. OVER THE PAST DECADE, SEVERAL METHODS HAVE BEEN APPLIED TO CHARACTERIZE DNA METHYLATION-SPECIFIC LOCI OF CONNEXIN GENES. THIS CHAPTER DESCRIBES ANALYSIS OF SELECTIVE CONNEXIN32 AND CONNEXIN43 GENE DNA METHYLATION IN HUMAN GASTRIC TISSUES USING METHYLATION-SPECIFIC PCR, BISULFITE-SPECIFIC PCR SEQUENCING AS WELL AS MASSARRAY TECHNIQUES. 2016 4 5066 20 PHTHALATES SUPPRESS TYPE I INTERFERON IN HUMAN PLASMACYTOID DENDRITIC CELLS VIA EPIGENETIC REGULATION. BACKGROUND: EXPOSURE TO ENVIRONMENTAL ENDOCRINE-DISRUPTING CHEMICALS (EDCS) IS ASSOCIATED WITH ALLERGY, CHRONIC INFLAMMATION, AND IMMUNODEFICIENCY. PHTHALATES, THE COMMON EDCS USED IN PLASTIC INDUSTRY, MAY ACT AS ADJUVANTS TO DISRUPT IMMUNE SYSTEM AND ENHANCE ALLERGY. PLASMACYTOID DCS (PDCS) ARE PREDOMINANT CELLS SECRETING TYPE I INTERFERON (IFN) AGAINST INFECTION AND ARE PROFESSIONAL ANTIGEN-PRESENTING CELLS IN REGULATING ADAPTIVE IMMUNITY. HOWEVER, THE EFFECTS OF PHTHALATES ON THE FUNCTION OF PDCS ARE UNKNOWN. METHODS: CIRCULATING PDCS WERE ISOLATED FROM HEALTHY SUBJECTS, WERE PRETREATED WITH DIETHYLHEXYL PHTHALATE (DEHP) AND BUTYL BENZYL PHTHALATE (BBP), AND WERE STIMULATED WITH TOLL-LIKE RECEPTOR (TLR)-9 AGONIST CPG. IFN-ALPHA/IFN-BETA LEVELS, SURFACE MARKERS, AND T-CELL STIMULATORY FUNCTION WERE INVESTIGATED USING ELISA, FLOW CYTOMETRY, AND PDC/T-CELL COCULTURE ASSAY. MECHANISMS WERE INVESTIGATED USING RECEPTOR ANTAGONISTS, PATHWAY INHIBITORS, WESTERN BLOTTING, AND CHROMATIN IMMUNOPRECIPITATION. RESULTS: DIETHYLHEXYL PHTHALATE AND BUTYL BENZYL PHTHALATE SUPPRESSED CPG-INDUCED IFN-ALPHA/IFN-BETA EXPRESSION IN PDCS, AND THE EFFECT WAS REVERSED BY ARYL HYDROCARBON RECEPTOR (AHR) ANTAGONIST. DIETHYLHEXYL PHTHALATE SUPPRESSED CPG-ACTIVATED MITOGEN-ACTIVATED PROTEIN KINASE (MAPK)-MEK1/2-ERK-ELK1 AND NFKAPPAB SIGNALING PATHWAYS. DIETHYLHEXYL PHTHALATE SUPPRESSED CPG-INDUCED INTERFERON REGULATORY FACTOR (IRF)-7 EXPRESSION BY SUPPRESSING HISTONE H3K4 TRIMETHYLATION AT IRF7 GENE PROMOTER REGION THROUGH INHIBITING TRANSLOCATION OF H3K4-SPECIFIC TRIMETHYLTRANSFERASE WDR5 FROM CYTOPLASM INTO NUCLEUS. BUTYL BENZYL PHTHALATE OR DIETHYLHEXYL PHTHALATE-TREATED PDCS SUPPRESSED IFN-GAMMA BUT ENHANCED IL-13 PRODUCTION BY CD4+ T CELLS. CONCLUSION: PHTHALATES MAY INTERFERE WITH IMMUNITY AGAINST INFECTION AND PROMOTE THE DEVIATION OF TH2 RESPONSE TO INCREASE ALLERGY BY ACTING ON HUMAN PDCS VIA SUPPRESSING IFN-ALPHA/IFN-BETA EXPRESSION AND MODULATING THE ABILITY TO STIMULATE T-CELL RESPONSES. 2013 5 1079 26 CLONAL XENOBIOTIC RESISTANCE DURING POLLUTION-INDUCED TOXIC INJURY AND HEPATOCELLULAR CARCINOGENESIS IN LIVER OF FEMALE FLOUNDER (PLATICHTHYS FLESUS (L.)). JUVENILE AND ADULT FEMALE FLOUNDER (PLATICHTHYS FLESUS (L.)) WERE CAUGHT EITHER IN THE ESTUARY OF THE MOST POLLUTED EUROPEAN RIVER, THE ELBE, OR AS CONTROLS IN A REFERENCE SITE TO STUDY POLLUTION-INDUCED XENOBIOTIC RESISTANCE IN THEIR LIVERS IN RELATION TO PATHOLOGICAL ALTERATIONS. IN JUVENILE FISH, LIVERS DISPLAYED REVERSIBLE AND IRREVERSIBLE DEGENERATIVE TOXIPATHIC LESION TYPES BUT NEVER SHOWED (PRE)NEOPLASTIC CHANGES. TUMOUR FREQUENCIES UP TO 70% WERE FOUND MACROSCOPICALLY IN LIVERS OF ADULT FEMALE FLOUNDER WHICH HAD PROGRESSED TO ADENOMAS AND CARCINOMAS IN THE MOST POLLUTED SITE. BECAUSE MALE ADULT FLOUNDER SHOW ONLY UP TO 50% OF LIVERS CONTAINING EARLY PRENEOPLASTIC FOCI BUT NEVER MALIGNANCIES, WE FOCUSSED OUR STUDY ON FEMALE INDIVIDUALS. (PRE)NEOPLASTIC CHANGES RANGED FROM EARLY EOSINOPHILIC FOCI TO BASOPHILIC FOCI, ADENOMAS AND HEPATOCELLULAR CARCINOMAS. ADENOMAS WERE GENERALLY EOSINOPHILIC WHEREAS CARCINOMAS WERE MAINLY BASOPHILIC. THESE PHENOTYPICAL SEQUENTIAL CHANGES STRONGLY RESEMBLE THOSE FOUND IN CHEMICALLY-INDUCED LIVER CARCINOGENESIS IN MAMMALS. CHARACTERISTIC MUTATIONS KNOWN FROM MAMMALIAN CANCERS HAVE NOT BEEN FOUND SO FAR IN THESE FLOUNDER LIVERS. THEREFORE, WE INVESTIGATED WHETHER EPIGENETIC EVENTS HAD INDUCED A METABOLIC "RESISTANT PHENOTYPE" OF (PRE)MALIGNANT CANCER CELLS DURING HEPATOCELLULAR CARCINOGENESIS. WITH A QUANTITATIVE IMMUNOHISTOCHEMICAL APPROACH, WE STUDIED EXPRESSION OF P-GLYCOPROTEIN (P-GP)-MEDIATED MULTIXENOBIOTIC RESISTANCE (MXR), CYTOCHROME P4501A1, GLUTATHIONE-S-TRANSFERASE-A WHICH ARE KEY PROTEINS IN XENOBIOTIC METABOLISM AND ELIMINATION. GLUCOSE-6-PHOSPHATE DEHYDROGENASE (G6PDH) ACTIVITY, THE MAJOR SOURCE OF THE REDUCING POWER NADPH WHICH IS NEEDED FOR BIOTRANSFORMATION, OXYRADICAL SCAVENGING AND BIOSYNTHESIS, WAS DETECTED AS WELL. WE OBSERVED UPREGULATION OF G6PDH ACTIVITY ALREADY IN EARLY PRENEOPLASTIC EOSINOPHILIC FOCI AND SUBSEQUENT FURTHER UPREGULATION IN BASOPHILIC FOCI AND CARCINOMAS. P-GP STARTED TO BECOME OVEREXPRESSED IN BASOPHILIC FOCI AND WAS OVEREXPRESSED EVEN MORE STRONGLY IN CARCINOMAS AND THEIR INVASIVELY-GROWING PROTRUSIONS (SATELLITES). IN CARCINOMAS, P-GP PROTEIN WAS PREDOMINANTLY PRESENT IN MEMBRANES OF LYSOSOMES WHICH ARE THE INTRACELLULAR SITES OF DEPOSITION OF XENOBIOTICS. CYP450 WAS REDUCED WHEREAS GST-A WAS INCREASED IN THESE CARCINOMAS. PROGRESSION TOWARDS MALIGNANCY WAS POSITIVELY CORRELATED WITH LEVELS OF MITOGENIC ORGANOCHLORINES IN THESE LIVERS WHICH ARE "FINGERPRINT CONTAMINANTS" OF THE RIVER ELBE. WE CONCLUDE THAT (PRE)NEOPLASTIC HEPATOCYTES IN FEMALE FLOUNDER ACQUIRE GROWTH ADVANTAGES OVER NORMAL HEPATOCYTES BY EPIGENETIC METABOLIC ADAPTATIONS DURING LIVER CARCINOGENESIS AS A RESULT OF CHRONIC EXPOSURE TO (PRO)CARCINOGENS IN THE POLLUTED HABITAT. 2004 6 5098 29 PLEIOTROPIC EFFECTS OF METHIONINE ADENOSYLTRANSFERASES DEREGULATION AS DETERMINANTS OF LIVER CANCER PROGRESSION AND PROGNOSIS. DOWNREGULATION OF LIVER-SPECIFIC MAT1A GENE, ENCODING S-ADENOSYLMETHIONINE (SAM) SYNTHESIZING ISOZYMES MATI/III, AND UPREGULATION OF WIDELY EXPRESSED MAT2A, ENCODING MATII ISOZYME, KNOWN AS MAT1A:MAT2A SWITCH, OCCURS IN HEPATOCELLULAR CARCINOMA (HCC). BEING INHIBITED BY ITS REACTION PRODUCT, MATII ISOFORM UPREGULATION CANNOT COMPENSATE FOR MATI/III DECREASE. THEREFORE, MAT1A:MAT2A SWITCH CONTRIBUTES TO DECREASE IN SAM LEVEL IN RODENT AND HUMAN HEPATOCARCINOGENESIS. SAM ADMINISTRATION TO CARCINOGEN-TREATED RATS PREVENTS HEPATOCARCINOGENESIS, WHEREAS MAT1A-KO MICE, CHARACTERIZED BY CHRONIC SAM DEFICIENCY, EXHIBIT MACROVESICULAR STEATOSIS, MONONUCLEAR CELL INFILTRATION IN PERIPORTAL AREAS, AND HCC DEVELOPMENT. THIS REVIEW FOCUSES UPON THE PLEIOTROPIC CHANGES, INDUCED BY MAT1A/MAT2A SWITCH, ASSOCIATED WITH HCC DEVELOPMENT. EPIGENETIC CONTROL OF MATS EXPRESSION OCCURS AT TRANSCRIPTIONAL AND POST-TRANSCRIPTIONAL LEVELS. IN HCC CELLS, MAT1A/MAT2A SWITCH IS ASSOCIATED WITH GLOBAL DNA HYPOMETHYLATION, DECREASE IN DNA REPAIR, GENOMIC INSTABILITY, AND SIGNALING DEREGULATION INCLUDING C-MYC OVEREXPRESSION, RISE IN POLYAMINE SYNTHESIS, UPREGULATION OF RAS/ERK, IKK/NF-KB, PI3K/AKT, AND LKB1/AMPK AXIS. FURTHERMORE, DECREASE IN MAT1A EXPRESSION AND SAM LEVELS RESULTS IN INCREASED HCC CELL PROLIFERATION, CELL SURVIVAL, AND MICROVASCULARIZATION. ALL OF THESE CHANGES ARE REVERSED BY SAM TREATMENT IN VIVO OR FORCED MAT1A OVEREXPRESSION OR MAT2A INHIBITION IN CULTURED HCC CELLS. IN HUMAN HCC, MAT1A:MAT2A AND MATI/III:MATII RATIOS CORRELATE NEGATIVELY WITH CELL PROLIFERATION AND GENOMIC INSTABILITY, AND POSITIVELY WITH APOPTOSIS AND GLOBAL DNA METHYLATION. THIS SUGGESTS THAT SAM DECREASE AND MATS DEREGULATION REPRESENT POTENTIAL THERAPEUTIC TARGETS FOR HCC. FINALLY, MATI/III:MATII RATIO STRONGLY PREDICTS PATIENTS' SURVIVAL LENGTH SUGGESTING THAT MAT1A:MAT2A EXPRESSION RATIO IS A PUTATIVE PROGNOSTIC MARKER FOR HUMAN HCC. 2013 7 6361 29 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 8 1996 21 EPIGENETIC AND GENETIC ALTERATIONS OF THE EDNRB GENE IN NASOPHARYNGEAL CARCINOMA. BACKGROUND: LOSS OF HETEROZYGOSITY (LOH) AT 13Q22 IS A COMMON EVENT IN NASOPHARYNGEAL CARCINOMA (NPC). EDNRB GENE LOCATED AT 13Q22 HAS BEEN DEMONSTRATED TO BE HYPERMETHYLATED IN SOME KINDS OF TUMORS. IN THE CURRENT STUDY, WE FOCUSED ON THE EPIGENETIC AND GENETIC ALTERATIONS OF EDNRB IN NPC. METHODS: THE MRNA EXPRESSION OF EDNRB WAS DETECTED BY SEMIQUANTITATIVE RT-PCR AND REAL-TIME QUANTITATIVE PCR IN 49 NPC AND 12 CHRONIC NASOPHARYNGITIS BIOPSIES. THE METHYLATION AND LOH STATUS OF EDNRB WERE EXAMINED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION, MICROSATELLITE PCR AND SEQUENCING. WE ALSO EXAMINED THE MRNA EXPRESSION OF EDNRB IN FOUR NPC CELL LINES AFTER 5-AZA-2'-DEOXYCYTIDINE TREATMENT. RESULTS: EDNRB WAS DOWNREGULATED IN PRIMARY NPC TISSUES AND NPC CELL LINES, AND A RELATIVELY HIGHER METHYLATION LEVEL OF EDNRB WAS FOUND IN NPC BIOPSIES (84%) COMPARED TO THAT IN CHRONIC NASOPHARYNGITIS BIOPSIES (42%). TREATMENT OF NPC CELL LINES WITH 5-AZA-2'-DEOXYCYTIDINE ACTIVATED EDNRB EXPRESSION. LOH OF EDNRB GENE WAS ALSO FOUND AT TWO MICROSATELLITE SITES WITH RATIOS OF 6.25 AND 16.67% IN NPC. CONCLUSION: OUR RESULTS SUGGESTED THAT EDNRB EXPRESSION MAY BE AFFECTED BY ABERRANT PROMOTER METHYLATION AND GENE DELETION AND MAY PLAY A ROLE IN THE DEVELOPMENT OF NPC. 2007 9 1700 28 DYNAMIC EXPRESSION OF ZNF382 AND ITS TUMOR-SUPPRESSOR ROLE IN HEPATITIS B VIRUS-RELATED HEPATOCELLULAR CARCINOGENESIS. HEPATITIS B VIRUS (HBV) INFECTION IS THE PRIMARY CAUSE OF HEPATOCELLULAR CARCINOMA (HCC). ZINC-FINGER PROTEIN 382 (ZNF382), WHICH BELONGS TO ZINC-FINGER PROTEIN FAMILY, HAS BEEN DOCUMENTED TO BE DOWNREGULATED IN CERTAIN TYPES OF CANCER. HOWEVER, ITS ROLE IN HCC REMAINS LARGELY UNKNOWN. IN THIS STUDY, WE DEMONSTRATED THAT ZNF382 EXPRESSION WAS SIGNIFICANTLY ELEVATED IN HBV-INFECTED LIVER CIRRHOSIS TISSUES RELATIVE TO HBV-NEGATIVE NORMAL LIVER TISSUES AT PROTEIN LEVELS, BUT NOT AT MRNA LEVELS, AND WAS POSITIVELY CORRELATED WITH THE LEVELS OF HBV DNA AND HEPATITIS B VIRUS X PROTEIN (HBX). FURTHER STUDIES REVEALED THAT ZNF382 WAS A TARGET OF MIR-6867, AND HBX PROMOTED THE TRANSLATION OF ZNF382 DURING HBV CHRONIC INFECTION THROUGH ERK-MEDIATED MIR-6867 INHIBITION. IN ADDITION, OUR DATA SHOWED THAT ZNF382 WAS FREQUENTLY DOWNREGULATED BY PROMOTER METHYLATION IN HBV-RELATED HCCS RELATIVE TO HBV-INFECTED LIVER CIRRHOSIS TISSUES, AND DECREASED EXPRESSION OF ZNF382 WAS STRONGLY CORRELATED WITH POOR SURVIVAL IN EARLY-STAGE HCC PATIENTS. FUNCTIONAL STUDIES DEMONSTRATED THAT ZNF382 WAS A POTENT TUMOR SUPPRESSOR IN HCC CELLS THROUGH INHIBITING CELL PROLIFERATION, COLONY FORMATION, MIGRATION, INVASION, AND TUMORIGENIC POTENTIAL IN NUDE MICE, AND INDUCING CELL APOPTOSIS. MECHANISTICALLY, ZNF382 EXERTED ITS TUMOR-SUPPRESSOR FUNCTIONS IN HCC THROUGH TRANSCRIPTIONALLY REPRESSING ITS DOWNSTREAM TARGETS SUCH AS FOS PROTO-ONCOGENE (FOS), JUN PROTO-ONCOGENE (JUN), DISHEVELED SEGMENT POLARITY PROTEIN 2 (DVL2), AND FRIZZLED CLASS RECEPTOR 1 (FZD1), THEREBY IMPAIRING THE ACTIVITIES OF ACTIVATING PROTEIN 1 (AP-1) AND WNT/BETA-CATENIN PATHWAYS AND ACTIVATING P53 SIGNALING. ALTOGETHER, OUR DATA SHOW THAT ZNF382 ACTS AS A TUMOR SUPPRESSOR, AND IS CO-REGULATED BY HBX AND EPIGENETIC MECHANISM IN HBV-RELATED HEPATOCELLULAR CARCINOGENESIS. 2019 10 4993 22 PENTOXIFYLLINE-INDUCED PROTEIN EXPRESSION CHANGE IN RAW 264.7 CELLS AS DETERMINED BY IMMUNOPRECIPITATION-BASED HIGH PERFORMANCE LIQUID CHROMATOGRAPHY. ALTHOUGH PENTOXIFYLLINE (PTX) WAS IDENTIFIED AS A COMPETITIVE NON-SELECTIVE PHOSPHODIESTERASE INHIBITOR, ITS PHARMACOLOGICAL EFFECT HAS NOT BEEN CLEARLY ELUCIDATED. THE PRESENT STUDY EXPLORED THE EFFECT OF LOW DOSE 10 MUG/ML PTX (THERAPEUTIC DOSE) COMPARED TO HIGH DOSE 300 MUG/ML PTX (EXPERIMENTAL DOSE) IN RAW 264.7 CELLS THROUGH IMMUNOPRECIPITATION-BASED HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (IP-HPLC), IMMUNOHISTOCHEMISTRY, AND WESTERN BLOT. 10 MUG/ML PTX INCREASED THE EXPRESSION OF PROLIFERATION (KI-67, PCNA, CYCLIN D2, CDC25A), EPIGENETIC MODIFICATION (KDM4D, PCAF, HMGB1), PROTEIN TRANSLATION (DOHH, DHPS, EIF5A1), RAS SIGNALING (KRAS, PAKT1/2/3, PI3K), NFKB SIGNALING (NFKB, GADD45, P38), PROTECTION (HSP70, SOD1, GSTO1/2), SURVIVAL (PAKT1/2/3, SP1, SIRTUIN 6), NEUROMUSCULAR DIFFERENTIATION (NSEGAMMA, MYOSIN-1A, DESMIN), OSTEOBLASTIC DIFFERENTIATION (BMP2, RUNX2, OSTERIX), ACUTE INFLAMMATION (TNFALPHA, IL-1, CXCR4), INNATE IMMUNITY (BETA-DEFENSIN 1, LACTOFERRIN, TLR-3, -4), CELL-MEDIATED IMMUNITY (CD4, CD8, CD80), WHILE DECREASED THE EXPRESSION OF ER STRESS (EIF2ALPHA, EIF2AK3, ATF6ALPHA), FIBROSIS (FGF2, CTGF, COLLAGEN 3A1), AND CHRONIC INFLAMMATION (CD68, MMP-2, -3, COX2) VERSUS THE UNTREATED CONTROLS. THE ACTIVATION OF PROLIFERATION BY 10 MUG/ML PTX WAS ALSO SUPPORTED BY THE INCREASE OF CMYC-MAX HETERODIMER AND BETA-CATENIN-TCF1 COMPLEX IN DOUBLE IP-HPLC. 10 MUG/ML PTX ENHANCED FAS-MEDIATED APOPTOSIS BUT DIMINISHED P53-MEDIATED APOPTOSIS, AND DOWNREGULATED MANY ANGIOGENESIS PROTEINS (ANGIOGENIN, VEGF-A, AND FLT4), BUT UPREGULATED HIF1ALPHA, VEGFR2, AND CMG2 REACTIVELY. WHEREAS, 300 MUG/ML PTX CONSISTENTLY DECREASED PROLIFERATION, EPIGENETIC MODIFICATION, RAS AND NFKB SIGNALING, NEUROMUSCULAR AND OSTEOBLASTIC DIFFERENTIATION, BUT INCREASED APOPTOSIS, ER STRESS, AND FIBROSIS COMPARED TO 10 MUG/ML PTX. THESE DATA SUGGEST PTX HAS DIFFERENT BIOLOGICAL EFFECT ON RWA 264.7 CELLS DEPENDING ON THE CONCENTRATION OF 10 MUG/ML AND 300 MUG/ML PTX. THE LOW DOSE 10 MUG/ML PTX ENHANCED RAS/NFKB SIGNALING, PROLIFERATION, DIFFERENTIATION, AND INFLAMMATION, PARTICULARLY, IT STIMULATED NEUROMUSCULAR AND OSTEOBLASTIC DIFFERENTIATION, INNATE IMMUNITY, AND CELL-MEDIATED IMMUNITY, BUT ATTENUATED ER STRESS, FIBROSIS, ANGIOGENESIS, AND CHRONIC INFLAMMATION, WHILE THE HIGH DOSE 300 MUG/ML PTX WAS FOUND TO ALLEVIATE THE 10 MUG/ML PTX-INDUCED BIOLOGICAL EFFECTS, RESULTED IN THE SUPPRESSION OF RAS/NFKB SIGNALING, PROLIFERATION, NEUROMUSCULAR AND OSTEOBLASTIC DIFFERENTIATION, AND INFLAMMATION. 2022 11 6816 20 [EXPRESSION, GENETIC AND EPIGENETIC ALTERATIONS OF LTF GENE IN NASOPHARYNGEAL CARCINOMA CELL LINES]. OBJECTIVE: TO INVESTIGATE THE EXPRESSION OF LTF MRNA IN SEVERAL NASOPHARYNGEAL CANCER (NPC) CELL LINES, AND ANALYZE THE RELATIONSHIP BETWEEN THE GENETIC AND EPIGENETIC CHANGES AND EXPRESSION OF LTF GENE. METHODS: THE EXPRESSION LEVEL OF LTF WAS DETECTED IN NPC CELL LINES HNE1, HNE2, HNE3, CNE1, CNE2, 5-8F, 6-10B CELLS AND TISSUES OF 15 CASES OF CHRONIC NASOPHARYNGITIS BY RT-PCR. THE LTF PROTEIN LEVEL WAS ANALYZED BY WESTERN BLOTTING IN 6-10B CELLS. THEN LOH, MUTATION AND METHYLATION STATUS OF LTF WAS EXAMINED BY MICROSATELLITES ANALYSIS, PCR-SSCP, MSP AND BISULFITE GENOMIC SEQUENCING, RESPECTIVELY. RESULTS: 15 CHRONIC NASOPHARYNGITIS TISSUES SHOWED STABLE LTF EXPRESSION, WHILE THERE WERE WEAK EXPRESSION IN 6-10B CELLS AND ABSENT EXPRESSION IN REMAINING DETECTED NPC CELL LINES. THERE WAS A SIGNIFICANTLY LOWER LTF EXPRESSION IN CHRONIC NASOPHARYNGITIS TISSUES (Z = -3.738, P = 0.000). NO LTF PROTEIN EXPRESSION WAS OBSERVED IN 6-10B CELLS. LOH ANALYSIS DEMONSTRATED THAT ALLELE LOSS OF LTF WASN'T FOUND IN NPC CELL LINES. LTF MUTATION WAS NOTED IN 14.3% (1/7) OF NPC CELL LINES. DNA SEQUENCING CONFIRMED THE MUTATION POINT IN THE PROMOTER REGION (-305 BP TO -50 BP) WAS AT -218 BP (DEL T) OF LTF GENE IN THE HNE1 CELL LINE. METHYLATION OF LTF GENE WAS NOT FOUND IN CHRONIC NASOPHARYNGITIS. HOWEVER, METHYLATION OF LTF PROMOTER WAS DETECTED IN ALL NPC CELL LINES. LTF MRNA EXPRESSION WAS INCREASED IN 5-8F AND 6-10B CELL LINES AFTER TREATMENT WITH 5-AZA-2-DEOXYCYTIDINE. CONCLUSION: THERE IS AN INACTIVATION OF EXPRESSION OF LTF GENE IN THE NPC CELL LINES. ITS MOLECULAR MECHANISM MAY BE RELATED WITH METHYLATION OF PROMOTER REGION AND DELETION MUTATION. 2010 12 3267 20 HEPATOCELLULAR CARCINOMA AND POSSIBLE CHEMICAL AND BIOLOGICAL CAUSES: A REVIEW. THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC) IS A MULTISTEP PROCESS. IN HCC, PROGRESSIVE AND MORPHOLOGICALLY DISTINCT PRENEOPLASTIC LESIONS/ALTERATIONS ASSOCIATED WITH CHRONIC LIVER INJURY, INFLAMMATION, HEPATOCELLULAR DEGENERATION/REGENERATION, NECROSIS, AND SMALL-CELL DYSPLASIA CAN BE OBSERVED. THE INCIDENCE OF HCC EXHIBITS REGIONAL AND ETHNIC DIFFERENCES. SEVERAL CYTOTOXIC AND DNA-DAMAGING CHEMICALS ARE SUGGESTED TO BE THE UNDERLYING CAUSES OF HCC-FOR EXAMPLE, ACRYLAMIDE, PERFLUOROOCTANOIC ACID (PFOA), POLYCHLORINATED BIPHENYLS (PCBS), BENZO(A)PYRENE (BAP), PERFLUORINATED CHEMICALS (PFCS), VINYL CHLORIDE MONOMER (VCM), AND DIETARY CONTAMINANTS (AFLATOXINS, OCHRATOXINS). ALSO SUGGESTED ARE SUBSTANCES OF ABUSE (ALCOHOL) AND BIOLOGICAL AGENTS, SUCH AS HEPATITIS B AND C AND HUMAN IMMUNODEFICIENCY VIRUS 1 (HIV-1). THESE CAN ACT THROUGH GENETIC AND/OR EPIGENETIC MECHANISMS. THIS REVIEW WILL SHORTLY ADDRESS THE GENETIC AND EPIGENETIC MECHANISMS OF HCC AND FOCUS ON CYTOTOXIC AND DNA-DAMAGING CHEMICALS AND BIOLOGICAL AGENTS, EXPOSURE TO WHICH ARE SUGGESTED TO LEAD TO HCC INITIATION, PROMOTION, AND/OR PROGRESSION. 2017 13 3627 24 INACTIVATION OF LARS2, LOCATED AT THE COMMONLY DELETED REGION 3P21.3, BY BOTH EPIGENETIC AND GENETIC MECHANISMS IN NASOPHARYNGEAL CARCINOMA. ALLELIC LOSS OF CHROMOSOME 3P, INCLUDING THE 3P21.3 REGION, IS FOUND IN 95-100% OF PRIMARY NASOPHARYNGEAL CARCINOMA (NPC) BIOPSIES, SUGGESTING THAT THIS REGION SHOULD HARBOR SOME TUMOR SUPPRESSOR GENES (TSGS) CLOSELY RELATED TO NPC DEVELOPMENT. SEVERAL TSGS LOCATED AT 3P21.3, SUCH AS RASSF1A, LTF AND BLU, HAVE BEEN DEMONSTRATED TO BE INVOLVED IN NPC DEVELOPMENT. LARS2 (LEUCYL-TRNA SYNTHETASE 2, MITOCHONDRIAL) IS ANOTHER GENE LOCATED IN THE CHROMOSOME 3 COMMON ELIMINATED REGION-1 (C3CER1) AT 3P21.3. IN THIS STUDY, WE FOCUSSED ON THE EPIGENETIC AND GENETIC ALTERATIONS OF LARS2 IN NPC. THE MRNA EXPRESSION OF LARS2 WAS DETECTED IN 36 NPC AND 8 CHRONIC NASOPHARYNGITIS (NP) TISSUES BY SEMI-QUANTITATIVE REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION (RT-PCR) AND REAL-TIME RT-PCR. SUBSEQUENTLY, THE MUTATION, ALLELIC LOSS, AND METHYLATION STATUS OF LARS2 WERE ANALYSED BY POLYMERASE CHAIN REACTION-SINGLE-STRAND CONFORMATION POLYMORPHISM (PCR-SSCP), HOMOZYGOUS DELETION (HD) ANALYSIS AND METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION IN PRIMARY NPC TISSUES. NO EXPRESSION OR DOWNREGULATION OF LARS2 WAS OBSERVED IN 78% OF PRIMARY NPC TISSUES. NO MUTATIONS, ASSESSED BY PCR-SSCP AND DNA SEQUENCING, WERE FOUND IN THE PROMOTER REGION AND EXON 1 OF LARS2 IN NPC TISSUES, WHEREAS HD WAS DETECTED IN 28% OF NPC SPECIMENS AT THE LARS2 LOCUS. IN ADDITION, HYPERMETHYLATION OF LARS2 WAS FOUND IN 64% OF NPC SAMPLES BUT ONLY IN 12.5% OF NP BIOPSIES. OUR DATA INDICATE THAT INACTIVATION OF LARS2 BY BOTH GENETIC AND EPIGENETIC MECHANISMS MAY BE A COMMON AND IMPORTANT EVENT IN THE CARCINOGENESIS OF NPC. 2009 14 2792 22 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 15 4819 25 OCCURRENCE OF TOXICITY AND CELL PROLIFERATION AFTER A SINGLE GAVAGE ADMINISTRATION OF CHLOROFORM TO MALE F344 RATS. CHLOROFORM, AN INDUSTRIAL SOLVENT AND ONE OF THE MOST COMMON ENVIRONMENTAL CONTAMINANTS WHICH PRODUCES CARCINOGENIC EFFECTS IN THE LIVER AND KIDNEY OF RODENTS, IS NOT GENOTOXIC IN MOST TRADITIONAL BACTERIAL AND MAMMALIAN TEST SYSTEMS. ITS CARCINOGENIC POTENTIAL APPEARS ATTRIBUTABLE TO THE SUSTAINED CELL TURNOVER (REGENERATIVE HYPERPLASIA) WHICH RESULTS FROM CHRONIC CHLOROFORM TOXICITY. IN THIS PRESENT STUDY, CELL PROLIFERATION (REPLICATIVE DNA SYNTHESIS, RDS) AND HISTOPATHOLOGICAL CHANGES IN HEPATOCYTES AND RENAL TUBULAR EPITHELIAL CELLS WERE ASSESSED IN MALE F344 RATS FOLLOWING A SINGLE GAVAGE CHLOROFORM EXPOSURE (50, 150 OR 500 MG/KG). IN ADDITION, BIOCHEMICAL PARAMETERS (BUN, GOT, LDH AND NAG) WERE EXAMINED USING PLASMA AND URINE SAMPLES. CELL PROLIFERATION AND HISTOPATHOLOGICAL CHANGES (E.G. HYPERTROPHY, NECROSIS, VACUOLATION) WERE ONLY SEEN AT THE DOSE OF 500 MG/KG IN THE LIVER AND KIDNEY. AT THE SAME DOSE, ALL BIOCHEMICAL MARKERS WERE INCREASED AT THE 24 TO 48 HR TIME POINTS. THESE RESULTS OBTAINED ARE THUS IN LINE WITH EARLIER FINDINGS POINTING TO EPIGENETIC CARCINOGENICITY. 1998 16 3615 23 IN VITRO FOLATE DEFICIENCY INDUCES DEOXYNUCLEOTIDE POOL IMBALANCE, APOPTOSIS, AND MUTAGENESIS IN CHINESE HAMSTER OVARY CELLS. THE GENETIC AND EPIGENETIC EFFECTS OF NUTRITIONAL FOLATE DEFICIENCY WERE STUDIED IN TWO CHINESE HAMSTER OVARY (CHO) CELL LINES. THE CHO-AA8 CELL LINE (HEMIZYGOUS AT THE APRT LOCUS) AND CHO-UV5 (DNA REPAIR-DEFICIENT MUTANT OF AA8) WERE CULTURED IN HAM'S F-12 MEDIUM OR IN CUSTOM-PREPARED HAM'S F-12 MEDIUM LACKING FOLIC ACID, THYMIDINE, AND HYPOXANTHINE. CELLS CULTURED ACUTELY IN THE FOLATE DEFICIENT MEDIUM EXHIBITED INITIAL GROWTH ARREST, FOLLOWED BY MASSIVE CELL DEATH AND DNA FRAGMENTATION INTO NUCLEOSOMAL MULTIMERS CHARACTERISTIC OF APOPTOSIS. ALTHOUGH PROLONGED CULTURE IN THE FOLATE DEFICIENT MEDIUM WAS CYTOSTATIC AND LETHAL TO THE MAJORITY CELLS, MINOR SUBPOPULATIONS IN BOTH CELL LINES FAILED TO INITIATE CELL DEATH, EXHIBITED PHENOTYPIC ABNORMALITIES, AND ADAPTED A SELECTIVE GROWTH ADVANTAGE UNDER MARGINAL FOLATE CONDITIONS. THESE "RESISTANT" CLONES EXHIBITED MAJOR ALTERATIONS IN DEOXYNUCLEOTIDE POOLS ASSOCIATED WITH AN INCREASE IN MUTANT FREQUENCY AT THE APRT LOCUS AS DETECTED BY RESISTANCE TO CYTOTOXICITY IN 8-AZAADENOSINE. THE MUTATION FREQUENCY IN THE DNA REPAIR-DEFICIENT CHO-UV5 CELLS WAS APPROXIMATELY 100-FOLD GREATER THAN THAT IN THE PARENTAL AA8 CLONES, UNDERSCORING THE IMPORTANCE OF DNA REPAIR UNDER CONDITIONS OF FOLATE DEFICIENCY AND NUCLEOTIDE POOL IMBALANCE. THE ENHANCED MUTATION FREQUENCY IN THE DNA REPAIR-COMPETENT FOLATE-DEFICIENT CHO-AA8 CELLS SUGGESTS THAT DNA REPAIR ACTIVITY IS LESS EFFECTIVE UNDER FOLATE-DEFICIENT CONDITIONS. THESE RESULTS ADD TO THE ACCUMULATING CLINICAL AND EXPERIMENTAL EVIDENCE RELATING CHRONIC FOLATE DEFICIENCY TO GENOMIC INSTABILITY AND CARCINOGENESIS. 1994 17 600 18 BETA-DEFENSINS AND ANALOGS IN HELICOBACTER PYLORI INFECTIONS: MRNA EXPRESSION LEVELS, DNA METHYLATION, AND ANTIBACTERIAL ACTIVITY. ANTIMICROBIAL PEPTIDES CAN PROTECT THE GASTRIC MUCOSA FROM BACTERIA, BUT HELICOBACTER PYLORI (H. PYLORI) CAN EQUALLY COLONIZE THE GASTRIC APPARATUS. TO UNDERSTAND BETA-DEFENSIN FUNCTION IN H. PYLORI-ASSOCIATED CHRONIC GASTRITIS, WE INVESTIGATED SUSCEPTIBILITY, HUMAN BETA-DEFENSIN MRNA EXPRESSION, AND DNA METHYLATION CHANGES TO PROMOTERS IN THE GASTRIC MUCOSA WITH OR WITHOUT H. PYLORI INFECTION. WE STUDIED THE EXPRESSION OF HBD2 (GENE NAME DEFB4A), HBD3 (DEFB103A), AND HBD4 (DEFB104) USING REAL-TIME PCR IN 15 CONTROL AND 10 H. PYLORI INFECTION PATIENT GASTRIC SPECIMENS. THIS STUDY DEMONSTRATES THAT H. PYLORI INFECTION IS RELATED TO GASTRIC ENHANCEMENT OF INDUCIBLE HBD2, BUT INDUCIBLE HBD3 AND HBD4 EXPRESSION LEVELS REMAINED UNCHANGED. HBD2 GENE METHYLATION LEVELS WERE OVERALL HIGHER IN H. PYLORI-NEGATIVE SAMPLES THAN IN H. PYLORI-POSITIVE SAMPLES. WE ALSO ASSESSED ANTIMICROBIAL SUSCEPTIBILITY USING GROWTH ON BLOOD AGAR. THE H. PYLORI STRAIN TOX+ WAS SUSCEPTIBLE TO ALL DEFENSINS TESTED AND THEIR ANALOGS (3N, 3NI). THESE RESULTS SHOW THAT HBD2 IS INVOLVED IN GASTRITIS DEVELOPMENT DRIVEN BY H. PYLORI, WHICH FACILITATES THE CREATION OF AN EPIGENETIC FIELD DURING H. PYLORI-ASSOCIATED GASTRIC TUMORIGENESIS. 2019 18 6849 22 [MOLECULAR MECHANISM OF HEPATOCARCINOGENESIS]. HEPATOCELLULAR CARCINOMA (HCC) IN JAPAN IS CLOSELY ASSOCIATED WITH THE CHRONIC LIVER DISEASES OF INFECTION WITH THE HEPATITIS B OR C VIRUSES. ANALYSIS OF HCC TISSUES FREQUENTLY DETECTS LOSS OF HETEROZYGOSITY AT CHROMOSOMES 1P, 4, 6Q, 8P, 10Q, 13Q, 16Q, 17P, AND MANY GENOMIC AND EPIGENOMIC ABNORMALITIES HAVE BEEN FOUND IN P53, BETA-CATENIN, P16CDKI, DNA MISMATCH REPAIR GENES, AND OTHERS. HOWEVER, NO SPECIFIC ABNORMAL GENETIC OR EPIGENETIC CHANGES FOR HCC HAVE BEEN FOUND SO FAR. THE DEVELOPMENT OF HCC HAS BEEN REPORTED IN MICE TRANSGENIC FOR THE HEPATITIS B VIRUS X GENE OR THE HEPATITIS C VIRUS CORE GENE, AND THESE VIRAL PROTEINS MIGHT PLAY ESSENTIAL ROLES IN HEPATOCARCINOGENESIS. CHRONIC HEPATITIS AND FIBROSIS DUE TO PERSISTENT VIRAL INFECTION MIGHT ALSO INFLUENCE THE GENOMIC INSTABILITY OF HEPATOCYTES, LEADING TO ACCUMULATION OF GENOMIC CHANGES. 1999 19 6487 28 TP53 MUTATIONS AND HEPATOCELLULAR CARCINOMA: INSIGHTS INTO THE ETIOLOGY AND PATHOGENESIS OF LIVER CANCER. HEPATOCELLULAR CARCINOMA (HCC) IS ONE OF THE MOST COMMON MALIGNANCIES WORLDWIDE AND THE MAJOR RISK FACTORS INCLUDE CHRONIC INFECTIONS WITH THE HEPATITIS B (HBV) OR C (HCV) VIRUS, AND EXPOSURE TO DIETARY AFLATOXIN B(1) (AFB(1)) OR ALCOHOL CONSUMPTION. MULTIPLE GENETIC AND EPIGENETIC CHANGES ARE INVOLVED IN THE MOLECULAR PATHOGENESIS OF HCC, FOR EXAMPLE, SOMATIC MUTATIONS IN THE P53 TUMOR SUPPRESSOR GENE (TP53) AND THE ACTIVATION OF THE WNT SIGNAL TRANSDUCTION PATHWAY. AFB(1) FREQUENTLY INDUCES G:C TO T:A TRANSVERSIONS AT THE THIRD BASE IN CODON 249 OF TP53 AND COOPERATES WITH HBV IN CAUSING P53 MUTATIONS IN HCC. THE DETECTION OF TP53 MUTANT DNA IN PLASMA IS A BIOMARKER OF BOTH AFB(1) EXPOSURE AND HCC RISK. CHRONIC INFECTION WITH HBV AND HCV VIRUSES, AND OXYRADICAL DISORDERS INCLUDING HEMOCHROMATOSIS, ALSO GENERATE REACTIVE OXYGEN/NITROGEN SPECIES THAT CAN BOTH DAMAGE DNA AND MUTATE CANCER-RELATED GENES SUCH AS TP53. CERTAIN MUTANT P53 PROTEINS MAY EXHIBIT A 'GAIN OF ONCOGENIC FUNCTION'. THE P53 BIOLOGICAL NETWORK IS A KEY RESPONDER TO THIS OXIDATIVE AND NITROSATIVE STRESS. DEPENDING ON THE EXTENT OF THE DNA DAMAGE, P53 REGULATES THE TRANSCRIPTION OF PROTECTIVE ANTIOXIDANT GENES AND WITH EXTENSIVE DNA DAMAGE, TRANSACTIVATES PRO-OXIDANT GENES THAT CONTRIBUTE TO APOPTOSIS. THE X GENE OF HBV (HBX) IS THE MOST COMMON OPEN READING FRAME INTEGRATED INTO THE HOST GENOME IN HCC AND THE INTEGRATED HBX IS FREQUENTLY MUTATED. MUTANT HBX PROTEINS STILL RETAIN THEIR ABILITY TO BIND TO P53, AND ATTENUATE DNA REPAIR AND P53-MEDIATED APOPTOSIS. IN SUMMARY, BOTH VIRUSES AND CHEMICALS ARE IMPLICATED IN THE ETIOLOGY OF TP53 MUTATIONS DURING THE MOLECULAR PATHOGENESIS OF HCC. 2007 20 1819 24 EFFECTS OF CHRONIC OCHRATOXIN A EXPOSURE ON P53 HETEROZYGOUS AND P53 HOMOZYGOUS MICE. EXPOSURE TO THE MYCOTOXIN OCHRATOXIN A (OTA) CAUSES NEPHROPATHY IN DOMESTIC ANIMALS AND RODENTS AND RENAL TUMORS IN RODENTS AND POULTRY. HUMANS ARE EXPOSED TO OTA BY CONSUMING FOODS MADE WITH CONTAMINATED CEREAL GRAINS AND OTHER COMMODITIES. MANAGEMENT OF HUMAN HEALTH RISKS DUE TO OTA EXPOSURE DEPENDS, IN PART, ON ESTABLISHING A MODE OF ACTION (MOA) FOR OTA CARCINOGENESIS. TO FURTHER INVESTIGATE OTA'S MOA, P53 HETEROZYGOUS (P53+/-) AND P53 HOMOZYGOUS (P53+/+) MICE WERE EXPOSED TO OTA IN DIET FOR 26 WEEKS. THE FORMER ARE SUSCEPTIBLE TO TUMORIGENESIS UPON CHRONIC EXPOSURE TO GENOTOXIC CARCINOGENS. OTA-INDUCED RENAL DAMAGE BUT NO TUMORS WERE OBSERVED IN EITHER STRAIN, INDICATING THAT P53 HETEROZYGOSITY CONFERRED LITTLE ADDITIONAL SENSITIVITY TO OTA. RENAL CHANGES INCLUDED DOSE-DEPENDENT INCREASES IN CELLULAR PROLIFERATION, APOPTOSIS, KARYOMEGALY, AND TUBULAR DEGENERATION IN PROXIMAL TUBULES, WHICH WERE CONSISTENT WITH OCHRATOXICOSIS. THE LOWEST OBSERVED EFFECT LEVEL FOR RENAL CHANGES IN P53+/- AND P53+/+ MICE WAS 200 MUG OTA/KG BW/DAY. BASED ON THE LACK OF TUMORS AND THE SEVERITY OF RENAL AND BODY WEIGHT CHANGES AT A MAXIMUM TOLERATED DOSE, THE RESULTS WERE INTERPRETED AS SUGGESTIVE OF A PRIMARILY NONGENOTOXIC (EPIGENETIC) MOA FOR OTA CARCINOGENESIS IN THIS MOUSE MODEL. 2015