1 1079 200 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 2 155 33 ABERRANT METHYLATION OF POLO-LIKE KINASE CPG ISLANDS IN PLK4 HETEROZYGOUS MICE. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC), ONE OF THE MOST COMMON CANCERS WORLD-WIDE OCCURS TWICE AS OFTEN IN MEN COMPARED TO WOMEN. PREDISPOSING CONDITIONS SUCH AS ALCOHOLISM, CHRONIC VIRAL HEPATITIS, AFLATOXIN B1 INGESTION, AND CIRRHOSIS ALL CONTRIBUTE TO THE DEVELOPMENT OF HCC. METHODS: WE USED A COMBINATION OF METHYLATION SPECIFIC PCR AND BISULFITE SEQUENCING, QREAL-TIME PCR (QPCR), AND WESTERN BLOT ANALYSIS TO EXAMINE EPIGENETIC CHANGES FOR THE POLO-LIKE KINASES (PLKS) DURING THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC) IN PLK4 HETEROZYGOUS MICE AND MURINE EMBRYONIC FIBROBLASTS (MEFS). RESULTS: HERE WE REPORT THAT THE PROMOTER METHYLATION OF PLK4 CPG ISLANDS INCREASES WITH AGE, WAS MORE PREVALENT IN MALES AND THAT PLK4 EPIGENETIC MODIFICATION AND SUBSEQUENT DOWNREGULATION OF EXPRESSION WAS ASSOCIATED WITH THE DEVELOPMENT OF HCC IN PLK4 MUTANT MICE. INTERESTINGLY, THE OPPOSITE OCCURS WITH ANOTHER PLK FAMILY MEMBER, PLK1 WHICH WAS TYPICALLY HYPERMETHYLATED IN NORMAL LIVER TISSUE BUT BECAME HYPOMETHYLATED AND UPREGULATED IN LIVER TUMOURS. FURTHERMORE, UPON ALCOHOL EXPOSURE MURINE EMBRYONIC FIBROBLASTS EXHIBITED INCREASED PLK4 HYPERMETHYLATION AND DOWNREGULATION ALONG WITH INCREASED CENTROSOME NUMBERS AND MULTINUCLEATION. CONCLUSIONS: THESE RESULTS SUGGEST THAT ABERRANT PLK METHYLATION IS CORRELATED WITH THE DEVELOPMENT OF HCC IN MICE. 2011 3 491 30 ASSESSING THE IMPACT OF POLYETHYLENE NANO/MICROPLASTIC EXPOSURE ON HUMAN VAGINAL KERATINOCYTES. THE GLOBAL RISE OF SINGLE-USE THROW-AWAY PLASTIC PRODUCTS HAS ELICITED A MASSIVE INCREASE IN THE NANO/MICROPLASTICS (N/MPLS) EXPOSURE BURDEN IN HUMANS. RECENTLY, IT HAS BEEN DEMONSTRATED THAT DISPOSABLE PERIOD PRODUCTS MAY RELEASE N/MPLS WITH USAGE, WHICH REPRESENTS A POTENTIAL THREAT TO WOMEN'S HEALTH WHICH HAS NOT BEEN SCIENTIFICALLY ADDRESSED YET. BY USING POLYETHYL ENE (PE) PARTICLES (200 NM TO 9 MUM), WE SHOWED THAT ACUTE EXPOSURE TO A HIGH CONCENTRATION OF N/MPLS INDUCED CELL TOXICITY IN VAGINAL KERATINOCYTES AFTER EFFECTIVE CELLULAR UPTAKE, AS VIABILITY AND APOPTOSIS DATA SUGGEST, ALONG WITH TRANSMISSION ELECTRON MICROSCOPY (TEM) OBSERVATIONS. THE INTERNALISED N/MPLS ALTERED THE EXPRESSION OF JUNCTIONAL AND ADHERENCE PROTEINS AND THE ORGANISATION OF THE ACTIN CORTEX, INFLUENCING THE LEVEL OF GENES INVOLVED IN OXIDATIVE STRESS SIGNALLING PATHWAYS AND THAT OF MIRNAS RELATED TO EPITHELIAL BARRIER FUNCTION. WHEN THE EXPOSURE TO PE N/MPLS WAS DISCONTINUED OR BECAME CHRONIC, CELLS WERE ABLE TO RECOVER FROM THE NEGATIVE EFFECTS ON VIABILITY AND DIFFERENTIATION/PROLIFERATION GENE EXPRESSION IN A FEW DAYS. HOWEVER, IN ALL CASES, PE N/MPL EXPOSURE PROMPTED A SUSTAINED ALTERATION OF DNA METHYLTRANSFERASE AND DNA DEMETHYLASE EXPRESSION, WHICH MIGHT IMPACT EPIGENETIC REGULATION PROCESSES, LEADING TO ACCELERATED CELL AGEING AND INFLAMMATION, OR THE OCCURRENCE OF MALIGNANT TRANSFORMATION. 2023 4 452 34 APPLICATION OF THE KEY CHARACTERISTICS OF CARCINOGENS TO PER AND POLYFLUOROALKYL SUBSTANCES. PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) CONSTITUTE A LARGE CLASS OF ENVIRONMENTALLY PERSISTENT CHEMICALS USED IN INDUSTRIAL AND CONSUMER PRODUCTS. HUMAN EXPOSURE TO PFAS IS EXTENSIVE, AND PFAS CONTAMINATION HAS BEEN REPORTED IN DRINKING WATER AND FOOD SUPPLIES AS WELL AS IN THE SERUM OF NEARLY ALL PEOPLE. THE MOST WELL-STUDIED MEMBER OF THE PFAS CLASS, PERFLUOROOCTANOIC ACID (PFOA), INDUCES TUMORS IN ANIMAL BIOASSAYS AND HAS BEEN ASSOCIATED WITH ELEVATED RISK OF CANCER IN HUMAN POPULATIONS. GENX, ONE OF THE PFOA REPLACEMENT CHEMICALS, INDUCES TUMORS IN ANIMAL BIOASSAYS AS WELL. USING THE KEY CHARACTERISTICS OF CARCINOGENS FRAMEWORK FOR CANCER HAZARD IDENTIFICATION, WE CONSIDERED THE EXISTING EPIDEMIOLOGICAL, TOXICOLOGICAL AND MECHANISTIC DATA FOR 26 DIFFERENT PFAS. WE FOUND STRONG EVIDENCE THAT MULTIPLE PFAS INDUCE OXIDATIVE STRESS, ARE IMMUNOSUPPRESSIVE, AND MODULATE RECEPTOR-MEDIATED EFFECTS. WE ALSO FOUND SUGGESTIVE EVIDENCE INDICATING THAT SOME PFAS CAN INDUCE EPIGENETIC ALTERATIONS AND INFLUENCE CELL PROLIFERATION. EXPERIMENTAL DATA INDICATE THAT PFAS ARE NOT GENOTOXIC AND GENERALLY DO NOT UNDERGO METABOLIC ACTIVATION. DATA ARE CURRENTLY INSUFFICIENT TO ASSESS WHETHER ANY PFAS PROMOTE CHRONIC INFLAMMATION, CELLULAR IMMORTALIZATION OR ALTER DNA REPAIR. WHILE MORE RESEARCH IS NEEDED TO ADDRESS DATA GAPS, EVIDENCE EXISTS THAT SEVERAL PFAS EXHIBIT ONE OR MORE OF THE KEY CHARACTERISTICS OF CARCINOGENS. 2020 5 4545 31 MUTANT P53 GAIN OF FUNCTION AND CHEMORESISTANCE: THE ROLE OF MUTANT P53 IN RESPONSE TO CLINICAL CHEMOTHERAPY. PURPOSE: TO REVIEW MECHANISMS UNDERLYING MUTANT P53 (MUTP53) GAIN OF FUNCTION (GOF) AND MUTP53-INDUCED CHEMORESISTANCE, AND TO INVESTIGATE THE ROLE OF MUTP53 IN RESPONSE TO CLINICAL CHEMOTHERAPY. METHODS: WE SEARCHED THE PUBMED DATABASE FOR CLINICAL STUDIES FROM THE PAST DECADE, INCLUDING DATA EVALUATING THE IMPACT OF MUTP53 IN CLINICAL CHEMOTHERAPY RESPONSE. RESULTS: INTERACTIONS BETWEEN MUTP53 AND TRANSCRIPTIONAL FACTORS, PROTEINS OR DNA STRUCTURES, AS WELL AS EPIGENETIC REGULATION, CONTRIBUTE TO MUTP53 GOF. MAJOR MECHANISMS OF MUTP53-INDUCED CHEMORESISTANCE INCLUDE ENHANCED DRUG EFFLUX AND METABOLISM, PROMOTING SURVIVAL, INHIBITING APOPTOSIS, UPREGULATING DNA REPAIR, SUPPRESSING AUTOPHAGY, ELEVATING MICROENVIRONMENTAL RESISTANCE AND INDUCING A STEM-LIKE PHENOTYPE. CLINICALLY, MUTP53 PREDICTED RESISTANCE TO CHEMOTHERAPY IN DIFFUSE LARGE B-CELL LYMPHOMA, AND ESOPHAGEAL AND OROPHARYNGEAL CANCERS, BUT ITS IMPACT ON CHRONIC LYMPHOCYTIC LEUKEMIA WAS UNCLEAR. IN BLADDER CANCER, MUTP53 DID NOT PREDICT RESISTANCE, WHEREAS IN SOME BREAST AND OVARIAN CANCERS, IT WAS ASSOCIATED WITH SENSITIVITY TO CERTAIN CHEMOTHERAPEUTIC AGENTS. CONCLUSION: MUTP53 HAS AN INTRICATE ROLE IN THE RESPONSE TO CLINICAL CHEMOTHERAPY AND SHOULD NOT BE INTERPRETED IN ISOLATION. FURTHERMORE, WHEN PREDICTING TUMOR RESPONSE TO CHEMOTHERAPY BASED ON THE P53 STATUS, THE DRUGS USED SHOULD ALSO BE TAKEN INTO CONSIDERATION. THESE CONCEPTS REQUIRE FURTHER INVESTIGATION. 2017 6 5688 38 SILENCING EFFECTS OF MUTANT RAS SIGNALLING ON TRANSCRIPTOMES. MUTATED GENES OF THE RAS FAMILY ENCODING SMALL GTP-BINDING PROTEINS DRIVE NUMEROUS CANCERS, INCLUDING PANCREATIC, COLON AND LUNG TUMORS. BESIDES THE NUMEROUS EFFECTS OF MUTANT RAS GENE EXPRESSION ON ABERRANT PROLIFERATION, TRANSFORMED PHENOTYPES, METABOLISM, AND THERAPY RESISTANCE, THE MOST STRIKING CONSEQUENCES OF CHRONIC RAS ACTIVATION ARE CHANGES OF THE GENETIC PROGRAM. BY PERFORMING SYSTEMATIC GENE EXPRESSION STUDIES IN CELLULAR MODELS THAT ALLOW COMPARISONS OF PRE-NEOPLASTIC WITH RAS-TRANSFORMED CELLS, WE AND OTHERS HAVE ESTIMATED THAT 7 PERCENT OR MORE OF ALL TRANSCRIPTS ARE ALTERED IN CONJUNCTION WITH THE EXPRESSION OF THE ONCOGENE. IN THIS CONTEXT, THE NUMBER OF UP-REGULATED TRANSCRIPTS APPROXIMATES THAT OF DOWN-REGULATED TRANSCRIPTS. WHILE UP-REGULATED TRANSCRIPTION FACTORS SUCH AS MYC, FOSL1, AND HMGA2 HAVE BEEN IDENTIFIED AND CHARACTERIZED AS RAS-RESPONSIVE DRIVERS OF THE ALTERED TRANSCRIPTOME, THE SUPPRESSED FACTORS HAVE BEEN LESS WELL STUDIED AS POTENTIAL REGULATORS OF THE GENETIC PROGRAM AND TRANSFORMED PHENOTYPE IN THE BREADTH OF THEIR OCCURRENCE. WE THEREFORE HAVE COLLECTED INFORMATION ON DOWNREGULATED RAS-RESPONSIVE FACTORS AND DISCUSS THEIR POTENTIAL ROLE AS TUMOR SUPPRESSORS THAT ARE LIKELY TO ANTAGONIZE ACTIVE CANCER DRIVERS. TO BETTER UNDERSTAND THE ACTIVE MECHANISMS THAT ENTAIL ANTI-RAS FUNCTION AND THOSE THAT LEAD TO LOSS OF TUMOR SUPPRESSOR ACTIVITY, WE FOCUS ON THE TUMOR SUPPRESSOR HREV107 (ALIAS PLAAT3 [PHOSPHOLIPASE A AND ACYLTRANSFERASE 3], PLA2G16 [PHOSPHOLIPASE A2, GROUP XVI] AND HRASLS3 [HRAS-LIKE SUPPRESSOR 3]). INACTIVATING HREV107 MUTATIONS IN TUMORS ARE EXTREMELY RARE, HENCE EPIGENETIC CAUSES MODULATED BY THE RAS PATHWAY ARE LIKELY TO LEAD TO DOWN-REGULATION AND LOSS OF FUNCTION. 2023 7 6464 27 TISSUE MISREPAIR HYPOTHESIS FOR RADIATION CARCINOGENESIS. DOSE-RESPONSE CURVES FOR CHRONIC LEUKEMIA IN A-BOMB SURVIVORS AND LIVER TUMORS IN PATIENTS GIVEN THOROTRAST (COLLOIDAL THORIUM DIOXIDE) SHOW LARGE THRESHOLD EFFECTS. THE EXISTENCE OF THESE THRESHOLD EFFECTS CAN BE EXPLAINED BY THE FOLLOWING HYPOTHESIS. A HIGH DOSE OF RADIATION CAUSES A PERSISTENT WOUND IN A CELL-RENEWABLE TISSUE. DISORDER OF THE INJURED CELL SOCIETY PARTLY FREES THE COMPONENT CELLS FROM TERRITORIAL RESTRAINTS ON THEIR PROLIFERATION, ENABLING THEM TO CONTINUE DEVELOPMENT OF THEIR CELLULAR FUNCTIONS TOWARD ADVANCED AUTONOMY. THIS PROGRESSION MIGHT BE ACHIEVED BY CONTINUED EPIGENETIC AND GENETIC CHANGES AS A RESULT OF OCCASIONAL ERRORS IN THE OTHERWISE CONCERTED HEALING ACTION OF VARIOUS ENDOGENOUS FACTORS RECRUITED FOR TISSUE REPAIR. CARCINOGENESIS IS NOT SIMPLY A SINGLE-CELL PROBLEM BUT A CELL-SOCIETY PROBLEM. THEREFORE, IT IS NOT WARRANTED TO ESTIMATE RISK AT LOW DOSES BY LINEAR EXTRAPOLATION FROM CANCER DATA AT HIGH DOSES WITHOUT KNOWLEDGE OF THE MECHANISM OF RADIATION CARCINOGENESIS. 1991 8 3468 39 HYPOXIA-INDUCED DNA HYPERMETHYLATION IN HUMAN PULMONARY FIBROBLASTS IS ASSOCIATED WITH THY-1 PROMOTER METHYLATION AND THE DEVELOPMENT OF A PRO-FIBROTIC PHENOTYPE. BACKGROUND: PULMONARY FIBROSIS IS A DEBILITATING AND LETHAL DISEASE WITH NO EFFECTIVE TREATMENT OPTIONS. UNDERSTANDING THE PATHOLOGICAL PROCESSES AT PLAY WILL DIRECT THE APPLICATION OF NOVEL THERAPEUTIC AVENUES. HYPOXIA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF PULMONARY FIBROSIS YET THE PRECISE MECHANISM BY WHICH IT CONTRIBUTES TO DISEASE PROGRESSION REMAINS TO BE FULLY ELUCIDATED. IT HAS BEEN SHOWN THAT CHRONIC HYPOXIA CAN ALTER DNA METHYLATION PATTERNS IN TUMOUR-DERIVED CELL LINES. THIS EPIGENETIC ALTERATION CAN INDUCE CHANGES IN CELLULAR PHENOTYPE WITH PROMOTER METHYLATION BEING ASSOCIATED WITH GENE SILENCING. OF PARTICULAR RELEVANCE TO IDIOPATHIC PULMONARY FIBROSIS (IPF) IS THE OBSERVATION THAT THY-1 PROMOTER METHYLATION IS ASSOCIATED WITH A MYOFIBROBLAST PHENOTYPE WHERE LOSS OF THY-1 OCCURS ALONGSIDE INCREASED ALPHA SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION. THE INITIAL AIM OF THIS STUDY WAS TO DETERMINE WHETHER HYPOXIA REGULATES DNA METHYLATION IN NORMAL HUMAN LUNG FIBROBLASTS (CCD19LU). AS IT HAS BEEN REPORTED THAT HYPOXIA SUPPRESSES THY-1 EXPRESSION DURING LUNG DEVELOPMENT WE ALSO STUDIED THE EFFECT OF HYPOXIA ON THY-1 PROMOTER METHYLATION AND GENE EXPRESSION. METHODS: CCD19LU WERE GROWN FOR UP TO 8 DAYS IN HYPOXIA AND ASSESSED FOR GLOBAL CHANGES IN DNA METHYLATION USING FLOW CYTOMETRY. REAL-TIME PCR WAS USED TO QUANTIFY EXPRESSION OF THY-1, ALPHA-SMA, COLLAGEN I AND III. GENOMIC DNA WAS BISULPHITE TREATED AND METHYLATION SPECIFIC PCR (MSPCR) WAS USED TO EXAMINE THE METHYLATION STATUS OF THE THY-1 PROMOTER. RESULTS: SIGNIFICANT GLOBAL HYPERMETHYLATION WAS DETECTED IN HYPOXIC FIBROBLASTS RELATIVE TO NORMOXIC CONTROLS AND WAS ACCOMPANIED BY INCREASED EXPRESSION OF MYOFIBROBLAST MARKERS. THY-1 MRNA EXPRESSION WAS SUPPRESSED IN HYPOXIC CELLS, WHICH WAS RESTORED WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE. MSPCR REVEALED THAT THY-1 BECAME METHYLATED FOLLOWING FIBROBLAST EXPOSURE TO 1% O2. CONCLUSION: THESE DATA SUGGEST THAT GLOBAL AND GENE-SPECIFIC CHANGES IN DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN FIBROBLAST FUNCTION IN HYPOXIA. 2012 9 6032 25 THE CARCINOGENIC INITIATING AND PROMOTING PROPERTIES OF A LIGHTLY REFINED PARAFFINIC OIL. THE DERMAL CARCINOGENIC POTENTIAL OF SOME PETROLEUM-DERIVED LIQUIDS IS RELATED TO THE POLYCYCLIC AROMATIC HYDROCARBON (PAH) CONTENT. HOWEVER, REPEATED APPLICATION OF MIDDLE DISTILLATES (MDS), E.G., KEROSENE, DIESEL FUEL, AND HEATING OIL, PRODUCED TUMORS IN MOUSE SKIN. THIS RESULT WAS UNEXPECTED SINCE THE MDS TYPICALLY CONTAIN VERY LOW LEVELS OF BIOLOGICALLY ACTIVE PAHS. THE PRESENT STUDY EXAMINED THE TUMORIGENIC MECHANISM OF A LIGHTLY REFINED PARAFFINIC OIL (LRPO), AN MD SHOWN TO BE ACTIVE IN MOUSE SKIN. THE LRPO WAS SEPARATED INTO SATURATED AND AROMATIC FRACTIONS. WHOLE LRPO AND VARIOUS FRACTIONS WERE TESTED FOR MUTAGENIC ACTIVITY IN THE SALMONELLA ASSAY AND FOR CARCINOGENIC INITIATING AND PROMOTING ACTIVITY. THERE WAS NO EVIDENCE THAT ANY OF THE SAMPLES EXAMINED WERE MUTAGENIC IN BACTERIA OR CARCINOGENIC INITIATING AGENTS IN MOUSE SKIN. THUS NO SUPPORT WAS PROVIDED FOR THE HYPOTHESIS THAT THE COMPLETE TUMORIGENIC ACTIVITY OF LRPO WAS IN ANY WAY RELATED TO THE PRESENCE OF LOW LEVELS OF PAHS OR TO AN INTERACTION BETWEEN INITIATING AND PROMOTING CONSTITUENTS. THERE WAS EVIDENCE THAT LRPO WAS A WEAK PROMOTER OF DIMETHYLBENZANTHRACENE (DMBA)-INITIATED MOUSE SKIN. IT WAS ALSO FOUND THAT REPEATED APPLICATION OF LRPO PRODUCED CHRONIC IRRITATION AND HYPERPLASIA, AND THIS MAY HAVE BEEN RESPONSIBLE FOR THE PROMOTIONAL EFFECTS. BASED ON THESE DATA, IT SEEMED LIKELY THAT THE COMPLETE CARCINOGENIC ACTIVITY OF THIS CLASS OF PRODUCTS IS ALSO THE RESULT OF AN EPIGENETIC PROCESS RELATED TO SKIN IRRITATION. 1989 10 493 25 ASSESSMENT OF P53 AND ATM FUNCTIONALITY IN CHRONIC LYMPHOCYTIC LEUKEMIA BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION. THE ATM-P53 DNA-DAMAGE RESPONSE (DDR) PATHWAY HAS A CRUCIAL ROLE IN CHEMORESISTANCE IN CLL, AS INDICATED BY THE ADVERSE PROGNOSTIC IMPACT OF GENETIC ABERRATIONS OF TP53 AND ATM. IDENTIFYING AND DISTINGUISHING TP53 AND ATM FUNCTIONAL DEFECTS HAS BECOME RELEVANT AS EPIGENETIC AND POSTTRANSCRIPTIONAL DYSREGULATION OF THE ATM/P53 AXIS IS INCREASINGLY BEING RECOGNIZED AS THE UNDERLYING CAUSE OF CHEMORESISTANCE. ALSO, SPECIFIC TREATMENTS SENSITIZING TP53- OR ATM-DEFICIENT CLL CELLS ARE EMERGING. WE THEREFORE DEVELOPED A NEW ATM-P53 FUNCTIONAL ASSAY WITH THE AIM TO (I) IDENTIFY AND (II) DISTINGUISH ABNORMALITIES OF TP53 VERSUS ATM AND (III) ENABLE THE IDENTIFICATION OF ADDITIONAL DEFECTS IN THE ATM-P53 PATHWAY. REVERSED TRANSCRIPTASE MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION (RT-MLPA) WAS USED TO MEASURE ATM AND/OR P53-DEPENDENT GENES AT THE RNA LEVEL FOLLOWING DNA DAMAGE USING IRRADIATION. HERE, WE SHOWED THAT THIS ASSAY IS ABLE TO IDENTIFY AND DISTINGUISH THREE SUBGROUPS OF CLL TUMORS (I.E., TP53-DEFECTIVE, ATM-DEFECTIVE AND WT) AND IS ALSO ABLE TO DETECT ADDITIONAL SAMPLES WITH A DEFECTIVE DDR, WITHOUT MOLECULAR ABERRATIONS IN TP53 AND/OR ATM. THESE FINDINGS MAKE THE ATM-P53 RT-MLPA FUNCTIONAL ASSAY A PROMISING PROGNOSTIC TOOL FOR PREDICTING TREATMENT RESPONSES IN CLL. 2015 11 2896 31 GASTRIC ENTEROCHROMAFFIN-LIKE CELL HYPERPLASIA AND NEOPLASIA IN THE RAT: AN INDIRECT EFFECT OF THE HISTAMINE H2-RECEPTOR ANTAGONIST, BL-6341. ORAL ADMINISTRATION OF BL-6341 HYDROCHLORIDE, A LONG-ACTING HISTAMINE H2-RECEPTOR ANTAGONIST, TO RATS FOR 2 YEARS AT DOSES OF 10, 55 OR 300 MG/KG/DAY RESULTED IN SEVERAL CHANGES IN THE FUNDIC (OXYNTIC) MUCOSA OF THE GLANDULAR STOMACH. THE MOST SIGNIFICANT ALTERATION WAS A PROLIFERATION OF ARGYROPHIL ENDOCRINE CELLS THAT WAS DEMONSTRATED TO BE ENTEROCHROMAFFIN-LIKE (ECL) CELLS. THE ECL CELL PROLIFERATION CONSISTED OF A CONTINUUM OF CHANGES INVOLVING DIFFUSE HYPERPLASIA, FOCAL ADENOMATOUS HYPERPLASIA, AND CARCINOID TUMOR FORMATION AT THE HIGHEST DOSE LEVEL OF 300 MG/KG. AT 55 MG/KG ONLY ECL CELL HYPERPLASIA OCCURRED, AND AT THE LOW DOSE OF 10 MG/KG THERE WERE NO REMARKABLE PROLIFERATIVE CHANGES. THE REFERENCE COMPOUND, CIMETIDINE (950 MG/KG), PRODUCED A DEGREE OF ECL CELL PROLIFERATION THAT WAS SLIGHTLY LESS, BUT NOT SIGNIFICANTLY DIFFERENT THAN, THAT OBSERVED WITH 55 MG/KG OF BL-6341. DOSE-RELATED ELEVATIONS OF SERUM GASTRIN WERE OBSERVED WITH BL-6341, WHILE CIMETIDINE PRODUCED HYPERGASTRINEMIA THAT WAS GENERALLY INTERMEDIATE BETWEEN THAT PRODUCED BY THE MIDDLE AND LOW DOSES OF BL-6341. THE HYPERGASTRINEMIA RESULTED FROM THE PHARMACOLOGIC INHIBITION OF ACID SECRETION, WHICH IS THE NEGATIVE FEEDBACK MECHANISM CONTROLLING THE PRODUCTION OF GASTRIN. ONLY THE 300 MG/KG DOSE OF BL-6341 PRODUCED A SIGNIFICANT, SUSTAINED (24 HOURS) HYPERGASTRINEMIA AND CARCINOID TUMORS. THE CHRONIC, SUSTAINED HYPERGASTRINEMIA WAS CONSIDERED TO BE THE PRIMARY CAUSE OF THE ECL CELL CARCINOID NEOPLASIA. ALL GENETIC TOXICOLOGY TESTS PERFORMED WITH BL-6341 WERE NEGATIVE. IT WAS CONCLUDED THAT THE DEMONSTRATED HYPERGASTRINEMIA REPRESENTS AN INDIRECT, HORMONAL, EPIGENETIC MECHANISM OF TUMORIGENESIS. 1988 12 6484 27 TOXICOLOGIC PROFILE OF ACRYLONITRILE. ACRYLONITRILE IS A MONOMER USED EXTENSIVELY AS A RAW MATERIAL IN THE MANUFACTURING OF ACRYLIC FIBERS, PLASTICS, SYNTHETIC RUBBERS, AND ACRYLAMIDE. IT HAS BEEN CLASSIFIED AS A PROBABLE HUMAN CARCINOGEN ACCORDING TO THE RESULTS OF NUMEROUS CHRONIC RAT BIOASSAYS. THE PRESENT REPORT SUMMARIZES THE TOXICITY DATA ON ACRYLONITRILE AND REVIEWS AVAILABLE DATA CONCERNING THE MECHANISM (GENETIC VERSUS EPIGENETIC) BY WHICH ACRYLONITRILE IS CARCINOGENIC IN RATS. FROM THE EVALUATION OF THE RELEVANT TOXICITY DATA, IT CAN BE CONCLUDED THAT ACRYLONITRILE IS INDEED CARCINOGENIC TO RATS AFTER EITHER ORAL OR INHALATIONAL EXPOSURE. HOWEVER, INFORMATION ON OTHER MAMMALIAN SPECIES IS LACKING, AND, MOREOVER, THE EXACT MECHANISM OF THE CARCINOGENIC PROCESS IS UNCLEAR. THEREFORE, IT IS RECOMMENDED TO CONDUCT AN ADDITIONAL LONG-TERM INHALATION CARCINOGENICITY STUDY WITH ACRYLONITRILE IN MICE, AS WELL AS STUDIES INTO THE MECHANISM BY WHICH ACRYLONITRILE INDUCES (BRAIN) TUMORS IN RATS (GENETIC VERSUS EPIGENETIC). 1998 13 2761 31 EXPRESSION OF TESTIS-SPECIFIC GENES, TEX101 AND ODF4, IN CHRONIC MYELOID LEUKEMIA AND EVALUATION OF TEX101 IMMUNOGENICITY. BACKGROUND AND OBJECTIVES: CANCER-TESTIS (CT) ANTIGENS ARE A GROUP OF ANTIGENS WITH A RESTRICTED EXPRESSION IN NORMAL TISSUES, EXCEPT TESTIS, AND THEY HAVE ABERRANT EXPRESSION IN DIFFERENT TUMORS. THIS PATTERN OF EXPRESSION HAS MADE THEM PROMISING TARGETS FOR IMMUNOTHERAPY AND CANCER DETECTION. OUR AIM WAS TO FIND NEW MEMBERS OF THIS GROUP THAT MIGHT BE USEFUL AS MARKERS IN THE DETECTION OF CANCER AND IMMUNOTHERAPY. DESIGN AND SETTING: A DESCRIPTIVE STUDY CONDUCTED IN REFERRAL CENTERS OF TEHRAN UNIVERSITY OF MEDICAL SCIENCE FROM JANUARY 2008 TO JANUARY 2009. PATIENTS AND METHODS: WE ANALYZED THE EXPRESSION OF TWO TESTIS-SPECIFIC GENES NAMED ODF4 (OUTER DENSE FIBER OF SPERM TAILS 4) AND TEX101 (TESTIS EXPRESSED 101) IN 20 CHRONIC MYELOID LEUKEMIA (CML) AND 20 NORMAL SAMPLES BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION AND SEQUENCING. IMMUNOGENICITY OF TEX101 WAS EVALUATED BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY. RESULTS: THESE TWO GENES WERE EXPRESSED IN 30% OF CML PATIENTS BUT NOT IN ANY OF THE HEALTHY DONORS. HUMORAL RESPONSE AGAINST TEX101 WAS NOT DETECTED IN ANY SAMPLES. CONCLUSIONS: TEX101 AND ODF4 ARE CT GENES USEFUL FOR DETECTION OF CML. UNLIKE MANY CT GENES, OVEREXPRESSION OF TEX101 WAS NOT SHOWN TO INDUCE IMMUNOLOGIC RESPONSES IN THESE SAMPLES. ACCORDING TO THE PREVIOUS STUDIES, OVEREXPRESSION OF TEX101 LEADS TO SUPPRESSION OF CANCER INVASION AND METASTASIS; THUS, THE INDUCTION OF THE EXPRESSION OF TEX101 IN CANCER BY EPIGENETIC MECHANISMS MAY BE A TREATMENT STRATEGY. 2012 14 222 30 ACUTE LIVER STEATOSIS TRANSLATIONALLY CONTROLS THE EPIGENETIC REGULATOR MIER1 TO PROMOTE LIVER REGENERATION IN A STUDY WITH MALE MICE. THE EARLY PHASE LIPID ACCUMULATION IS ESSENTIAL FOR LIVER REGENERATION. HOWEVER, WHETHER THIS ACUTE LIPID ACCUMULATION CAN SERVE AS SIGNALS TO DIRECT LIVER REGENERATION RATHER THAN SIMPLY PROVIDING BUILDING BLOCKS FOR CELL PROLIFERATION REMAINS UNCLEAR. THROUGH IN VIVO CRISPR SCREENING, WE IDENTIFY MIER1 (MESODERM INDUCTION EARLY RESPONSE 1) AS A KEY EPIGENETIC REGULATOR THAT BRIDGES THE ACUTE LIPID ACCUMULATION AND CELL CYCLE GENE EXPRESSION DURING LIVER REGENERATION IN MALE ANIMALS. PHYSIOLOGICALLY, LIVER ACUTE LIPID ACCUMULATION INDUCES THE PHOSPHORYLATION OF EIF2S1(EUKARYOTIC TRANSLATION INITIATION FACTOR 2), WHICH CONSEQUENTLY ATTENUATED MIER1 TRANSLATION. MIER1 DOWNREGULATION IN TURN PROMOTES CELL CYCLE GENE EXPRESSION AND REGENERATION THROUGH CHROMATIN REMODELING. IMPORTANTLY, THE LIPIDS-EIF2S1-MIER1 PATHWAY IS IMPAIRED IN ANIMALS WITH CHRONIC LIVER STEATOSIS; WHEREAS MIER1 DEPLETION SIGNIFICANTLY IMPROVES REGENERATION IN THESE ANIMALS. TAKEN TOGETHER, OUR STUDIES IDENTIFY AN EPIGENETIC MECHANISM BY WHICH THE EARLY PHASE LIPID REDISTRIBUTION FROM ADIPOSE TISSUE TO LIVER DURING REGENERATION IMPACTS HEPATOCYTE PROLIFERATION, AND SUGGEST A POTENTIAL STRATEGY TO BOOST LIVER REGENERATION. 2023 15 6421 32 THE THERAPEUTIC PROPERTIES OF RESMINOSTAT FOR HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE MOST COMMON FORM OF PRIMARY LIVER CANCER WITH INCREASES IN NEW CASES BEING REPORTED ANNUALLY. HISTOPATHOLOGISTS HAVE IDENTIFIED HEPATIC STEATOSIS AS A CHARACTERISTIC OF A BROAD RANGE OF CHRONIC LIVER DISEASES THAT ARE ASSOCIATED WITH THE ONSET AND DEVELOPMENT OF HCC. IN THIS CONTEXT, EPIGENETIC MODIFICATIONS MAY SERVE AS PRECANCEROUS FACTORS PREDISPOSING NORMAL CELLS TO THE INITIATION OF CARCINOGENESIS. THIS STUDY DEMONSTRATED THAT HEPATIC TUMORIGENESIS AND DIFFERENTIATED ADIPOCYTES MAY MODULATE BOTH GLOBAL HISTONE DEACETYLASE (HDAC) EXPRESSION AND SPECIFIC CLASS I HDAC GENES IN THE TUMOUR MICROENVIRONMENT. THE NOVEL CLASS I HDAC INHIBITOR RESMINOSTAT WAS SHOWN TO REDUCE THE PROLIFERATION OF HCC CELLS ALONG WITH ITS SPECIFICITY IN TARGETING CLASS I HDACS AND ONCOGENES. THE COMBINED EFFECT OF RESMINOSTAT WITH SEVERAL PHARMACEUTICAL AGENTS SUCH AS SORAFENIB, CISPLATIN AND DOXORUBICIN WAS ALSO DEMONSTRATED. THE INHIBITION OF HEAT SHOCK PROTEIN 90 (HSP90) HAS BEEN DEMONSTRATED AS A POTENTIAL THERAPEUTIC OPTION FOR HCC. IN LINE WITH THIS, THE SPECIFIC HSP90 INHIBITOR 17-(ALLYLAMINO)-17-DEMETHOXYGELDANAMYCIN (17-AAG) WAS SELECTED AND IT WAS FOUND THAT THE COMBINATION OF RESMINOSTAT AND 17-AAG MAY PROVIDE A "SMART" CLINICAL STRATEGY FOR HCC PATIENTS BY TARGETING CELLULAR COMMUNICATION WITHIN THE TUMOUR MICROENVIRONMENT. THIS STUDY PROVIDES AN INSIGHT INTO THE USE OF RESMINOSTAT AS AN EPIGENETIC BASED THERAPEUTIC FOR HCC ALONG WITH OTHER PHARMACEUTICAL OPTIONS, IN PARTICULAR BY TARGETING THE CELL-TO-CELL COMMUNICATION THAT OCCURS BETWEEN HEPATOMA AND ADIPOCYTES. 2018 16 6584 32 TRIGGERING RECEPTORS EXPRESSED ON MYELOID CELLS 1 : OUR NEW PARTNER IN HUMAN ONCOLOGY? INFLAMMATION IS RECOGNIZED AS ONE OF THE HALLMARKS OF CANCER. INDEED, STRONG EVIDENCE INDICATES THAT CHRONIC INFLAMMATION PLAYS A MAJOR ROLE IN ONCOGENESIS, PROMOTING GENOME INSTABILITY, EPIGENETIC ALTERATIONS, PROLIFERATION AND DISSEMINATION OF CANCER CELLS. MONONUCLEAR PHAGOCYTES (MPS) HAVE BEEN IDENTIFIED AS KEY CONTRIBUTORS OF THE INFLAMMATORY INFILTRATE IN SEVERAL SOLID HUMAN NEOPLASIA, PROMOTING ANGIOGENESIS AND CANCER PROGRESSION. ONE OF THE MOST DESCRIBED AMPLIFIERS OF MPS PRO-INFLAMMATORY INNATE IMMUNE RESPONSE IS THE TRIGGERING RECEPTORS EXPRESSED ON MYELOID CELLS 1 (TREM-1). GROWING EVIDENCE SUGGESTS TREM-1 INVOLVEMENT IN ONCOGENESIS THROUGH CANCER RELATED INFLAMMATION AND THE SURROUNDING TUMOR MICROENVIRONMENT. IN HUMAN ONCOLOGY, HIGH LEVELS OF TREM-1 AND/OR ITS SOLUBLE FORM HAVE BEEN ASSOCIATED WITH POORER SURVIVAL DATA IN SEVERAL SOLID MALIGNANCIES, ESPECIALLY IN HEPATOCELLULAR CARCINOMA AND LUNG CANCER. TREM-1 SHOULD BE CONSIDERED AS A POTENTIAL BIOMARKER IN HUMAN ONCOLOGY AND COULD BE USED AS A NEW THERAPEUTIC TARGET OF INTEREST IN HUMAN ONCOLOGY (TREM-1 INHIBITORS, TREM-1 AGONISTS). MORE CLINICAL STUDIES ARE URGENTLY NEEDED TO CONFIRM TREM-1 (AND TREM FAMILY) ROLES IN THE PROGNOSIS AND THE TREATMENT OF HUMAN SOLID CANCERS. 2022 17 1121 29 COMPARISON OF EPIGENETIC PROFILES OF HUMAN ORAL EPITHELIAL CELLS FROM HIV-POSITIVE (ON HAART) AND HIV-NEGATIVE SUBJECTS. HIV-INFECTED SUBJECTS ON HIGHLY ACTIVE ANTIRETROVIRAL THERAPY (HAART) ARE SUSCEPTIBLE TO COMORBID MICROBIAL INFECTIONS IN THE ORAL CAVITY. WE OBSERVED THAT PRIMARY ORAL EPITHELIAL CELLS (POECS) ISOLATED FROM HIV+ SUBJECTS ON HAART GROW MORE SLOWLY AND ARE LESS INNATE IMMUNE RESPONSIVE TO MICROBIAL CHALLENGE WHEN COMPARED WITH POECS FROM NORMAL SUBJECTS. THESE ABERRANT CELLS ALSO DEMONSTRATE EPIGENETIC DIFFERENCES THAT INCLUDE REDUCTION IN HISTONE DEACETYLASE 1 (HDAC-1) LEVELS AND REDUCED TOTAL DNA METHYLTRANSFERASE (DNMT) ACTIVITY SPECIFIC TO ENZYMES DNMT1 AND DNMT3A. THE DNMT ACTIVITY CORRELATES WELL WITH GLOBAL DNA METHYLATION, INDICATING THAT ABERRANT DNMT ACTIVITY IN HIV+ (ON HAART) POECS LEADS TO AN ABERRANTLY METHYLATED EPITHELIAL CELL PHENOTYPE. OVERALL, OUR RESULTS LEAD US TO HYPOTHESIZE THAT, IN PATIENTS WITH CHRONIC HIV INFECTION ON HAART, EPIGENETIC CHANGES IN KEY GENES RESULT IN INCREASED VULNERABILITY TO MICROBIAL INFECTION IN THE ORAL CAVITY. 2013 18 546 38 ATTENUATED EXPRESSION OF SLCO2A1 CAUSED BY DNA METHYLATION IN PEDIATRIC INFLAMMATORY BOWEL DISEASE. BACKGROUND: SLCO2A1 ENCODES A PROSTAGLANDIN (PG) TRANSPORTER, AND AUTOSOMAL RECESSIVE PATHOGENIC VARIANTS OF THIS GENE CAUSE CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1. IT IS UNCLEAR WHETHER A HETEROZYGOUS PATHOGENIC VARIANT OF SLCO2A1 HAS A ROLE IN THE PATHOGENESIS OF OTHER TYPES OF INFLAMMATORY BOWEL DISEASE (IBD). IN THIS STUDY, WE INVESTIGATED THE POSSIBLE INVOLVEMENT OF A LOCAL EPIGENETIC ALTERATION IN SLCO2A1 IN PATIENTS WITH A HETEROZYGOUS PATHOGENIC VARIANT. METHODS: WE CONDUCTED WHOLE-EXOME SEQUENCING OF SAMPLES FROM 2 SISTERS WITH SUSPECTED MONOGENIC IBD. IN ADDITION, WE PERFORMED BISULFITE SEQUENCING USING DNA EXTRACTED FROM THEIR SMALL AND LARGE INTESTINE SAMPLES TO EXPLORE EPIGENETIC ALTERATIONS. RESULTS: A HETEROZYGOUS SPLICING SITE VARIANT, SLCO2A1:C.940 + 1G > A, WAS DETECTED IN BOTH PATIENTS. TO EXPLORE THE POSSIBLE INVOLVEMENT OF EPIGENETIC ALTERATIONS, WE ANALYZED PROTEIN AND MESSENGER RNA EXPRESSION OF SLCO2A1, AND OBSERVED ATTENUATED SLCO2A1 EXPRESSION IN THE INFLAMED LESIONS OF THESE PATIENTS COMPARED WITH THAT IN THE CONTROL INDIVIDUALS. FURTHERMORE, BISULFITE SEQUENCING INDICATED DENSE METHYLATION IN THE PROMOTER REGION OF SLCO2A1 ONLY IN THE INFLAMED LESIONS OF BOTH PATIENTS. THE URINARY PG METABOLITE LEVELS IN THESE PATIENTS WERE COMPARABLE TO THOSE IN PATIENTS WITH CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1 AND HIGHER THAN THOSE IN THE CONTROL INDIVIDUALS. WE FOUND CONSIDERABLY HIGHER LEVELS OF THE METABOLITES IN PATIENT 1, WHO SHOWED MORE SEVERE SYMPTOMS THAN PATIENT 2. CONCLUSIONS: LOCAL DNA METHYLATION ATTENUATED SLCO2A1 EXPRESSION, WHICH MAY EVOKE LOCAL INFLAMMATION OF THE MUCOSA BY THE UNINCORPORATED PG. THESE FINDINGS MAY IMPROVE OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS UNDERLYING IBD DEVELOPMENT. 2023 19 5433 25 REL/NF-KAPPA B/I KAPPA B SIGNAL TRANSDUCTION IN THE GENERATION AND TREATMENT OF HUMAN CANCER. THE REL/NF-KAPPA B FAMILY IS A GROUP OF STRUCTURALLY-RELATED, TIGHTLY-REGULATED TRANSCRIPTION FACTORS THAT CONTROL THE EXPRESSION OF A MULTITUDE OF GENES INVOLVED IN KEY CELLULAR AND ORGANISMAL PROCESSES. THE REL/NF-KAPPA B SIGNAL TRANSDUCTION PATHWAY IS MISREGULATED IN A VARIETY OF HUMAN CANCERS, ESPECIALLY ONES OF LYMPHOID CELL ORIGIN, DUE EITHER TO GENETIC CHANGES (SUCH AS CHROMOSOMAL REARRANGEMENTS, AMPLIFICATIONS, AND MUTATIONS) OR TO CHRONIC ACTIVATION OF THE PATHWAY BY EPIGENETIC MECHANISMS. CONSTITUTIVE ACTIVATION OF THE REL/NF-KAPPA B PATHWAY CAN CONTRIBUTE TO THE ONCOGENIC STATE IN SEVERAL WAYS, FOR EXAMPLE, BY DRIVING PROLIFERATION, BY ENHANCING CELL SURVIVAL, OR BY PROMOTING ANGIOGENESIS OR METASTASIS. IN MANY CASES, INHIBITION OF REL/NF-KAPPA B ACTIVITY REVERSES ALL OR PART OF THE MALIGNANT STATE. THUS, THE REL/NF-KAPPA B PATHWAY HAS RECEIVED MUCH ATTENTION AS A FOCAL POINT FOR CLINICAL INTERVENTION. 2002 20 4736 33 NOVEL EPIGENETIC BIOMARKERS MEDIATING BISPHENOL A EXPOSURE AND METABOLIC PHENOTYPES IN FEMALE MICE. THERE IS COMPELLING EVIDENCE THAT EPIGENETIC MODIFICATIONS LINK DEVELOPMENTAL ENVIRONMENTAL INSULTS TO ADULT DISEASE SUSCEPTIBILITY. ANIMAL STUDIES HAVE ASSOCIATED PERINATAL BISPHENOL A (BPA) EXPOSURE TO ALTERED DNA METHYLATION, BUT THESE STUDIES ARE OFTEN LIMITED TO CANDIDATE GENE AND GLOBAL NON-LOCI-SPECIFIC APPROACHES. BY USING AN EPIGENOME-WIDE DISCOVERY PLATFORM, WE ELUCIDATED EPIGENETIC ALTERATIONS IN LIVER TISSUE FROM ADULT MICE OFFSPRING (10 MONTHS) FOLLOWING PERINATAL BPA EXPOSURE AT HUMAN PHYSIOLOGICALLY RELEVANT DOSES (50-NG, 50-MUG, AND 50-MG BPA/KG DIET). BIOLOGICAL PATHWAY ANALYSIS IDENTIFIED AN ENRICHMENT OF SIGNIFICANT DIFFERENTIALLY METHYLATED REGIONS IN METABOLIC PATHWAYS AMONG FEMALES. FURTHERMORE, THROUGH THE USE OF TOP ENRICHED BIOLOGICAL PATHWAYS, 4 CANDIDATE GENES WERE CHOSEN TO ASSESS DNA METHYLATION AS A MEDIATING FACTOR LINKING THE ASSOCIATION OF PERINATAL BPA EXPOSURE TO METABOLIC PHENOTYPES PREVIOUSLY OBSERVED IN FEMALE OFFSPRING. DNA METHYLATION STATUS AT JANUS KINASE-2 (JAK-2), RETINOID X RECEPTOR (RXR), REGULATORY FACTOR X-ASSOCIATED PROTEIN (RFXAP), AND TRANSMEMBRANE PROTEIN 238 (TMEM238) WAS USED WITHIN A MEDIATIONAL REGRESSION ANALYSIS. DNA METHYLATION IN ALL FOUR OF THE CANDIDATE GENES WAS IDENTIFIED AS A MEDIATOR IN THE MECHANISTIC PATHWAY OF DEVELOPMENTAL BPA EXPOSURE AND FEMALE-SPECIFIC ENERGY EXPENDITURE, BODY WEIGHT, AND BODY FAT PHENOTYPES. DATA GENERATED FROM THIS STUDY ARE CRUCIAL FOR DECIPHERING THE MECHANISTIC ROLE OF EPIGENETICS IN THE PATHOGENESIS OF CHRONIC DISEASE AND THE DEVELOPMENT OF EPIGENETIC-BASED PREVENTION AND THERAPEUTIC STRATEGIES FOR COMPLEX HUMAN DISEASE. 2017