1 5843 97 STUDIES ON THE CARCINOGENICITY OF POTASSIUM IODIDE IN F344 RATS. A CHRONIC TOXICITY AND CARCINOGENICITY STUDY, IN WHICH MALE AND FEMALE F344/DUCRJ RATS WERE GIVEN POTASSIUM IODIDE (KI) IN THE DRINKING WATER AT CONCENTRATIONS OF 0, 10, 100 OR 1000 PPM FOR 104 WEEKS, AND A TWO-STAGE CARCINOGENICITY STUDY OF APPLICATION AT 0 OR 1000 PPM FOR 83 WEEKS FOLLOWING A SINGLE INJECTION OF N-BIS(2-HYDROXYPROPYL)NITROSAMINE (DHPN), WERE CONDUCTED. IN THE FORMER, SQUAMOUS CELL CARCINOMAS WERE INDUCED IN THE SALIVARY GLANDS OF THE 1000 PPM GROUP, BUT NO TUMORS WERE OBSERVED IN THE THYROID. IN THE TWO-STAGE CARCINOGENICITY STUDY, THYROIDAL WEIGHTS AND THE INCIDENCE OF THYROID TUMORS DERIVED FROM THE FOLLICULAR EPITHELIUM WERE SIGNIFICANTLY INCREASED IN THE DHPN+KI AS COMPARED WITH THE DHPN ALONE GROUP. THE RESULTS OF OUR STUDIES SUGGEST THAT EXCESS KI HAS A THYROID TUMOR-PROMOTING EFFECT, BUT KI PER SE DOES NOT INDUCE THYROID TUMORS IN RATS. IN THE SALIVARY GLAND, KI WAS SUGGESTED TO HAVE CARCINOGENIC POTENTIAL VIA AN EPIGENETIC MECHANISM, ONLY ACTIVE AT A HIGH DOSE. 2000 2 977 35 CHRONIC ORAL EXPOSURE TO INORGANIC ARSENATE INTERFERES WITH METHYLATION STATUS OF P16INK4A AND RASSF1A AND INDUCES LUNG CANCER IN A/J MICE. ALTHOUGH INORGANIC ARSENATE (IAS(V)) OR ARSENITE (IAS(III)) IS CLEARLY A HUMAN CARCINOGEN, IT HAS BEEN DIFFICULT TO PRODUCE TUMORS IN RODENTS. IN THE PRESENT STUDY, WE ORALLY ADMINISTERED IAS(V) TO A/J MICE TO EXAMINE ARSENIC CARCINOGENICITY IN RODENT. A/J MICE (MALE, N = 120) ASSIGNED TO FOUR GROUPS WERE GIVEN DRINKING WATER CONTAINING 0, 1, 10, AND 100 PPM IAS(V) FOR 18 MONTHS. AT THE END OF EXPERIMENT, THE COMPLETE LUNGS WERE REMOVED AND USED FOR EXAMINING HISTOPATHOLOGY AND EXTRACTING RNA AND DNA. EPIGENETIC EFFECTS OF IAS(V) ON DNA METHYLATION PATTERNS OF P16INK4A AND RASSF1A GENES WERE DETERMINED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. CHANGES OF P16INK4A AND RASSF1A AT MRNA AND PROTEIN LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION AND IMMUNOHISTOCHEMISTRY. ARSENIC WAS ACCUMULATED DOSE DEPENDENTLY IN THE LUNG TISSUES OF IAS(V)-EXPOSED MICE. INCREASE IN LUNG TUMOR NUMBER AND LUNG TUMOR SIZE WAS OBSERVED IN IAS(V)-EXPOSED MICE COMPARED TO THE CONTROL. HISTOPATHOLOGICAL EXAMINATION SHOWED THAT THE RATE OF POORLY DIFFERENTIATED LUNG ADENOCARCINOMA WAS MUCH HIGHER IN IAS(V)-EXPOSED MICE THAN IN THE CONTROL. METHYLATION RATES APPEARED TO BE HIGHER IN A DOSE-RELATED TENDENCY IN LUNG TUMORS FROM IAS(V)-EXPOSED MICE COMPARED TO THE CONTROL. LOWER OR LOSS OF P16INK4A AND RASSF1A EXPRESSION WAS FOUND IN LUNG TUMORS FROM IAS(V)-EXPOSED MICE, COMPARED TO THAT IN NONTUMOR LUNG TISSUES FROM BOTH CONTROL AND IAS(V)-EXPOSED MICE, AND THIS REDUCED OR LOST EXPRESSION WAS IN ACCORDANCE WITH HYPERMETHYLATION OF THE GENES. IN CONCLUSION, IAS(V) EXPOSURE INCREASED LUNG TUMOR INCIDENCE AND MULTIPLICITY IN A/J MICE. EPIGENETIC CHANGES OF TUMOR SUPPRESSOR GENES SUCH AS P16INK4A AND RASSF1A ARE INVOLVED IN THE IAS(V)-INDUCED LUNG CARCINOGENESIS. 2006 3 489 31 ASSESSING POTENTIAL MECHANISMS OF ARSENIC-INDUCED SKIN LESIONS AND CANCERS: HUMAN AND IN VITRO EVIDENCE. ENVIRONMENTAL EXPOSURE TO ARSENIC IS A MAJOR PUBLIC HEALTH CHALLENGE WORLDWIDE. IN DETAILING THE HALLMARK SIGNS OF CHRONIC ARSENIC EXPOSURE, PREVIOUS STUDIES HAVE SHOWN THAT EPIGENETIC AND IMMUNE DYSFUNCTION ARE ASSOCIATED WITH ARSENIC-INDUCED SKIN LESIONS; HOWEVER, KNOWLEDGE REGARDING INTERACTIONS BETWEEN THE MECHANISMS LISTED ABOVE IS LIMITED. IN THIS STUDY, A TOTAL OF 106 SKIN SAMPLES WERE COLLECTED OVER THE PAST 20 YEARS. BASED ON THE PRESENCE OR ABSENCE OF HIGH ARSENIC EXPOSURE, THE PARTICIPANTS WERE DIVIDED INTO ARSENIC EXPOSURE (72) AND REFERENCE (34) GROUPS. ADDITIONALLY, THE ARSENIC EXPOSURE GROUP WAS FURTHER DIVIDED INTO THE NON-CANCER GROUP (31, INCLUDING SKIN HYPERPIGMENTATION AND HYPERKERATOSIS) AND THE SKIN CANCER GROUP (41, INCLUDING BOWEN'S DISEASE, BASAL CELL CARCINOMA AND SQUAMOUS CELL CARCINOMA) ACCORDING TO A SKIN HISTOPATHOLOGICAL EXAMINATION. FIRST, THE ASSOCIATIONS AMONG MIR-155, NF-AT1 WITH IMMUNOLOGICAL DYSFUNCTION AND ARSENIC-INDUCED SKIN LESIONS AND CARCINOGENESIS WERE CONFIRMED USING THESE SKIN SAMPLES. IN THE ARSENIC-EXPOSED GROUP, MIR-155-5P, KERATIN 1(KRT1), KERATIN 10 (KRT10), AND KERATIN 6C (KRT6C) WERE SIGNIFICANTLY INCREASED IN THE SKIN (P < 0.05), WHILE NF-AT1, INTERLEUKIN-2 (IL-2), AND INTERFERON-GAMMA (IFN-GAMMA) WERE SIGNIFICANTLY DECREASED (P < 0.05). CLEAR CORRELATIONS WERE OBSERVED AMONG THESE FACTORS (P < 0.05). IN IMMORTALIZED HUMAN KERATINOCYTES, SILENCING AND OVEREXPRESSION OF NF-AT1 COULD ALTER THE EXPRESSION AND SECRETION OF IMMUNOLOGICAL DYSFUNCTION INDICATORS (IL-2 AND IFN-GAMMA) THAT ARE INDUCED BY ARSENIC EXPOSURE (P < 0.05); HOWEVER, MIR-155-5P LEVELS DID NOT CHANGE SIGNIFICANTLY (P > 0.05). THE MIR-155-5P MIMIC AND INHIBITOR COULD REGULATE THE NF-AT1-MEDIATED IMMUNOLOGICAL DYSFUNCTION CAUSED BY ARSENIC (P < 0.05). OUR STUDY PROVIDES SOME LIMITED EVIDENCE THAT MIR-155-5P REGULATES THE NF-AT1-MEDIATED IMMUNOLOGICAL DYSFUNCTION THAT IS INVOLVED IN THE PATHOGENESIS AND CARCINOGENESIS OF ARSENIC. THE SECOND MAJOR FINDING WAS THAT KRT1 AND KRT10 ARE MARKERS OF HYPERKERATOSIS CAUSED BY ARSENIC, AND KRT6C IS A POTENTIAL BIOMARKER THAT CAN REFLECT ARSENIC CARCINOGENESIS. 2020 4 6488 28 TP53 R72P POLYMORPHISM MODULATES DNA METHYLATION IN HEPATOCELLULAR CARCINOMA. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC) IS CHARACTERIZED BY WIDESPREAD EPIDEMIOLOGICAL AND MOLECULAR HETEROGENEITY. PREVIOUS WORK SHOWED THAT IN THE WESTERN PART OF NORTH AFRICA, A REGION OF LOW INCIDENCE OF HCC, MUTATIONS ARE SCARCE FOR THIS TUMOR TYPE. AS EPIGENETIC CHANGES ARE CONSIDERED POSSIBLE SURROGATES TO MUTATIONS IN HUMAN CANCERS, WE DECIDED, THUS, TO CHARACTERIZE DNA METHYLATION IN HCC FROM NORTH-AFRICAN PATIENTS. METHODS: A SET OF 11 LOCI WAS INVESTIGATED IN A SERIES OF 45 TUMOR SPECIMENS USING METHYLATION-SPECIFIC AND COMBINED-BISULFITE RESTRICTION ASSAY PCR. RESULTS OBTAINED ON CLINICAL SAMPLES WERE SUBSEQUENTLY VALIDATED IN LIVER CANCER CELL LINES. RESULTS: DNA METHYLATION AT TUMOR SUPPRESSOR LOCI IS SIGNIFICANTLY HIGHER IN SAMPLES DISPLAYING CHROMOSOME INSTABILITY. MORE IMPORTANTLY, DNA METHYLATION WAS SIGNIFICANTLY HIGHER IN ARG/ARG WHEN COMPARED TO PRO/PRO GENOTYPE CARRIERS AT CODON 72 RS1042522 OF TP53 (65% VS 20% METHYLATED LOCI, P = 0.0006), A POLYMORPHISM ALREADY KNOWN TO AFFECT SOMATIC MUTATION RATE IN HUMAN CARCINOMAS. IN VITRO EXPERIMENTS IN CELL LINES INDICATED THAT ENZYMES CONTROLLING DNA METHYLATION WERE DIFFERENTIALLY REGULATED BY CODON 72 ARG OR PRO ISOFORMS OF P53. FURTHERMORE, THE ARG72-CARRYING VERSION OF P53 WAS SHOWN TO RE-METHYLATE DNA MORE RAPIDLY THAN THE PRO-HARBORING ISOFORM. FINALLY, PRO-CARRYING CELL LINES WERE SHOWN TO BE SIGNIFICANTLY MORE RESISTANT TO DECITABINE TREATMENT (TWO-FOLD, P = 0.005). CONCLUSIONS: OUR DATA SUGGEST THAT ARG72PRO POLYMORPHISM IN A WT P53 CONTEXT MAY ACT AS A PRIMARY DRIVER OF EPIGENETIC CHANGES IN HCC. IT SUGGESTS, IN ADDITION, THAT RS1042522 GENOTYPE MAY PREDICT SENSITIVITY TO EPIGENETIC-TARGETED THERAPY. THIS MODEL OF LIVER TUMORIGENESIS THAT ASSOCIATES LOW PENETRANCE GENETIC PREDISPOSITION TO EPIGENETIC CHANGES EMERGES FROM A REGION OF LOW HCC INCIDENCE AND IT MAY, THEREFORE, APPLY ESSENTIALLY TO POPULATION LIVING IN SIMILAR AREAS. SURVEYS ON POPULATIONS SUBMITTED TO HIGHLY MUTAGENIC CONDITIONS AS PERINATALLY-ACQUIRED CHRONIC HEPATITIS B OR AFLATOXIN B1 EXPOSURE REMAINED TO BE CONDUCTED TO VALIDATE OUR OBSERVATIONS AS A GENERAL MODEL. 2015 5 6794 27 [EFFECT OF BENZO(A)PYRENE ON THE EXPRESSION OF AHR-REGULATED MICRORNA IN FEMALE AND MALE RAT LUNGS]. SMOKING IS THE MAIN RISK FACTOR FOR LUNG CANCER, MAINLY DUE TO PRESENCE OF NITROSAMINES AND POLYCYCLIC AROMATIC HYDROCARBONS, INCLUDING BENZO[A]PYRENE (BP) IN TOBACCO SMOKE COMPOSITION. THE GENOTOXIC EFFECT OF BP IS BASED ON THE HIGH DNA-BINDING ABILITY OF ITS METABOLITES, WHILE THE EPIGENETIC EFFECTS ARE MEDIATED BY A CHANGE IN THE EXPRESSION OF CANCER RELATED GENES OR REGULATORY RNAS. IT HAS BEEN SHOWN THAT WOMEN HAVE A HIGHER RISK TO DEVELOP LUNG CANCER UPON SMOKING RATHER THAN MEN. WE HYPOTHESIZED THAT CROSSTALK BETWEEN SIGNALING PATHWAYS ACTIVATED BY BP AND ESTROGENS COULD UNDERLIE THE SEX-DEPENDENT DIFFERENCES IN MIRNAS EXPRESSION. TO TEST THIS HYPOTHESIS, MALE AND FEMALE RATS WERE SUBJECTED TO SHORT-TERM OR LONG-TERM BP EXPOSURE. USING IN SILICO ANALYSIS, MIRNAS CONTAINING THE ER- AND AHR-BINDING SITES IN THE PROMOTERS OF THE GENES (OR HOST GENES) WERE SELECTED. DURING CHRONIC EXPOSURE OF BP THE EXPRESSION OF MIR-22-3P, -29A-3P, -126A-3P, -193B-5P IN THE LUNGS OF MALE RATS WERE SIGNIFICANTLY INCREASED, WHILE THE LEVEL OF MIRNA-483-3P WERE DECREASED. EXPRESSION OF MIRNA-483-3P WAS UP-REGULATED DURING CHRONIC BP EXPOSURE IN THE LUNGS OF FEMALE RATS AND THE LEVELS OF OTHER STUDIED MIRNAS WERE UNCHANGED. IN TURN, CHANGES IN THE EXPRESSION OF MIRNAS WERE FOLLOWED BY CHANGES IN THE EXPRESSION OF THEIR TARGET GENES, INCLUDING PTEN, EMP2, IGF1, ITGA6, SLC34A2, AND THE OBSERVED CHANGES IN FEMALE AND MALE RAT LUNGS WERE VARIED. THUS, OUR RESULTS SUGGEST THAT SEX-DEPENDENT EPIGENETIC EFFECTS OF BP MAY BE BASED ON DIFFERENT EXPRESSION OF AHR- AND ER- REGULATED MIRNAS. 2020 6 1011 22 CIGARETTE SMOKE CONDENSATE INDUCES DIFFERENTIAL EXPRESSION AND PROMOTER METHYLATION PROFILES OF CRITICAL GENES INVOLVED IN LUNG CANCER IN NL-20 LUNG CELLS IN VITRO: SHORT-TERM AND CHRONIC EXPOSURE. ESTABLISHING EARLY DIAGNOSTIC MARKERS OF HARM IS CRITICAL FOR EFFECTIVE PREVENTION PROGRAMS AND REGULATION OF TOBACCO PRODUCTS. THIS STUDY EXAMINED EFFECTS OF CIGARETTE SMOKE CONDENSATE (CSC) ON EXPRESSION AND PROMOTER METHYLATION PROFILE OF CRITICAL GENES (DAPK, ECAD, MGMT, AND RASSF1A) INVOLVED IN LUNG CANCER DEVELOPMENT IN DIFFERENT HUMAN LUNG CELL LINES. NL-20 CELLS WERE TREATED WITH 0.1-100 MUG/ML OF CSC FOR 24 TO 72 HRS FOR SHORT-TERM EXPOSURES. DAPK EXPRESSION OR METHYLATION STATUS WAS NOT SIGNIFICANTLY AFFECTED. HOWEVER, CSC TREATMENT RESULTED IN CHANGES IN EXPRESSION AND PROMOTER METHYLATION PROFILE OF ECAD, MGMT, AND RASSF1A. FOR CHRONIC STUDIES, CELLS WERE EXPOSED TO 1 OR 10 MUG/ML CSC UP TO 28 DAYS. CELLS SHOWED MORPHOLOGICAL CHANGES ASSOCIATED WITH TRANSFORMATION AND CHANGES IN INVASION CAPACITIES AND GLOBAL METHYLATION STATUS. THIS STUDY PROVIDES CRITICAL DATA SUGGESTING THAT EPIGENETIC CHANGES COULD SERVE AS AN EARLY BIOMARKER OF HARM DUE TO EXPOSURE TO CIGARETTE SMOKE. 2013 7 4528 19 MULTIGENERATIONAL EFFECTS OF CADMIUM ON THE LIFESPAN AND FERTILITY OF DROSOPHILA MELANOGASTER. ALTHOUGH THE DAMAGE AND TOLERANCE MECHANISMS OF CD STRESS ARE KNOWN, THE DATA ON GENETIC RISK ARE LIMITED. THE AIM OF THIS STUDY WAS TO ASSESS THE CHRONIC TOXICITY OF CD, GENETIC RESPONSES, AND MULTIGENERATIONAL EFFECTS IN FIVE GENERATIONS OF DROSOPHILA MELANOGASTER. FOR EACH GENERATION, LIFESPAN AND FERTILITY WERE STATISTICALLY ANALYSED AND THE EXPRESSION OF APOPTOSIS- (P53 AND CASPASE-3) AND EPIGENESIS-RELATED (DDNMT2 AND DMBD2/3) GENES WAS EXAMINED. LIFESPAN AND FERTILITY SIGNIFICANTLY DECLINED UNDER CD STRESS AND THESE EFFECTS WERE MAINTAINED FOR TWO GENERATIONS AND ONE GENERATION, RESPECTIVELY, WHEN CD STRESS WAS REMOVED. THE EXPRESSION OF P53 AND CASPASE-3 WAS SIGNIFICANTLY UP-REGULATED AFTER EXPOSURE, SUGGESTING THAT APOPTOSIS CONTRIBUTES TO THE RESISTANCE MECHANISM. THEIR ALTERED EXPRESSION WAS RETAINED FOR TWO GENERATIONS. FURTHERMORE, HIGH EXPRESSION OF DDNMT2 AND DMBD2/3 ACCOMPANIED CD EXPOSURE, WHICH WAS PASSED ON TO THREE GENERATIONS, SUGGESTING THAT GENETIC MODIFICATIONS IN APOPTOSIS-RELATED GENES ARE CARRIED TO THE OFFSPRING THROUGH EPIGENETIC REGULATION. 2020 8 1545 27 DNA METHYLATION IN LIVER TUMORIGENESIS IN FISH FROM THE ENVIRONMENT. THE LINK BETWEEN ENVIRONMENT, ALTERATION IN DNA METHYLATION AND CANCER HAS BEEN WELL ESTABLISHED IN HUMANS; YET, IT IS UNDER-STUDIED IN UNSEQUENCED NON-MODEL ORGANISMS. THE OCCURRENCE OF LIVER TUMORS IN THE FLATFISH DAB COLLECTED AT CERTAIN UK SAMPLING SITES EXCEEDS 20%, YET THE CAUSATIVE AGENTS AND THE MOLECULAR MECHANISMS OF TUMOR FORMATION ARE NOT KNOWN, ESPECIALLY REGARDING THE BALANCE BETWEEN EPIGENETIC AND GENETIC FACTORS. METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) COMBINED WITH DE NOVO HIGH-THROUGHPUT DNA SEQUENCING WERE USED TO INVESTIGATE DNA METHYLATION CHANGES IN DAB HEPATOCELLULAR ADENOMA TUMORS FOR THE FIRST TIME IN AN UNSEQUENCED SPECIES. NOVEL CUSTOM-MADE DAB GENE EXPRESSION ARRAYS WERE DESIGNED AND USED TO DETERMINE THE RELATIONSHIP BETWEEN DNA METHYLATION AND GENE EXPRESSION. IN ADDITION, THE CONFIRMATORY TECHNIQUES OF BISULFITE SEQUENCING PCR (BSP) AND RT-PCR WERE APPLIED. GENES INVOLVED IN PATHWAYS RELATED TO CANCER, INCLUDING APOPTOSIS, WNT/BETA-CATENIN SIGNALING AND GENOMIC AND NON-GENOMIC ESTROGEN RESPONSES, WERE ALTERED BOTH IN METHYLATION AND TRANSCRIPTION. GLOBAL METHYLATION WAS STATISTICALLY SIGNIFICANTLY 1.8-FOLD REDUCED IN HEPATOCELLULAR ADENOMA AND NON-CANCEROUS SURROUNDING TISSUES COMPARED WITH LIVER FROM NON-CANCER BEARING DAB. BASED ON THE IDENTIFIED CHANGES AND CHEMICAL EXPOSURE DATA, OUR STUDY SUPPORTS THE EPIGENETIC MODEL OF CANCER. WE HYPOTHESIZE THAT CHRONIC EXPOSURE TO A MIXTURE OF ENVIRONMENTAL CONTAMINANTS CONTRIBUTES TO A GLOBAL HYPOMETHYLATION FOLLOWED BY FURTHER EPIGENETIC AND GENOMIC CHANGES. THE FINDINGS SUGGEST A LINK BETWEEN ENVIRONMENT, EPIGENETICS AND CANCER IN FISH TUMORS IN THE WILD AND SHOW THE UTILITY OF THIS METHODOLOGY FOR STUDIES IN NON-MODEL ORGANISMS. 2011 9 1965 30 EPIGENETIC ALTERATION OF MITOCHONDRIAL BIOGENESIS REGULATORY GENES IN ARSENIC EXPOSED INDIVIDUALS (WITH AND WITHOUT SKIN LESIONS) AND IN SKIN CANCER TISSUES: A CASE CONTROL STUDY. CHRONIC ARSENIC TOXICITY HAS BECOME A GLOBAL CONCERN DUE TO ITS ADVERSE PATHOPHYSIOLOGICAL OUTCOME AND CARCINOGENIC POTENTIAL. IT IS ALREADY ESTABLISHED THAT ARSENIC INDUCED REACTIVE OXYGEN SPECIES ALTERS MITOCHONDRIAL FUNCTIONALITY. MAJOR REGULATORY GENES FOR MITOCHONDRIAL BIOGENESIS, I.E., PGC1ALPHA, TFAM, NRF1AND NRF2 ARE LOCATED IN THE NUCLEUS. AS A RESULT, MITOCHONDRIA-NUCLEUS CROSSTALK IS CRUCIAL FOR PROPER MITOCHONDRIAL FUNCTION. THIS PREVIOUS HYPOTHESIS LED US TO INVESTIGATEINVOLVEMENT OF EPIGENETIC ALTERATION BEHINDENHANCED MITOCHONDRIAL BIOGENESIS IN CHRONIC ARSENIC EXPOSURE. AN EXTENSIVE CASE-CONTROL STUDY WAS CONDUCTED WITH 390 STUDY PARTICIPANTS (UNEXPOSED, EXPOSED WITHOUT SKIN LESION, EXPOSED WITH SKIN LESION AND EXPOSED SKIN TUMOUR) FROM HIGHLY ARSENIC EXPOSED AREAS OFWEST BENGAL, INDIA. METHYLATION SPECIFIC PCRREVEALED SIGNIFICANT PROMOTER HYPOMETHYLATION OFTWO KEY BIOGENESIS REGULATORY GENES, PGC1ALPHAANDTFAM IN ARSENIC EXPOSED INDIVIDUALS AND ALSO IN SKIN TUMOUR TISSUES. LINEAR REGRESSION ANALYSIS INDICATED SIGNIFICANT NEGATIVE CORRELATION BETWEEN URINARY ARSENIC CONCENTRATION AND PROMOTER METHYLATION STATUS. INCREASED EXPRESSION OF BIOGENESIS REGULATORY GENES WASOBTAINED BY QUANTITATIVE REAL-TIME PCR ANALYSIS. MOREOVER, ALTERED MITOCHONDRIAL FUSION-FISSION REGULATORY GENE EXPRESSION WAS ALSO OBSERVED IN SKIN TUMOUR TISSUES. MIR663, HAVING TUMOUR SUPPRESSOR GENE LIKE FUNCTION WAS KNOWN TO BE EPIGENETICALLY REGULATED THROUGH MITOCHONDRIAL RETROGRADE SIGNAL. PROMOTER HYPERMETHYLATION WITH SIGNIFICANTLY DECREASED EXPRESSION OF MIR663 WAS FOUND IN SKIN CANCER TISSUES COMPARED TO NON-CANCEROUS CONTROL TISSUE. IN CONCLUSION, RESULTS INDICATED CRUCIAL ROLE OF EPIGENETIC ALTERATION IN ARSENIC INDUCED MITOCHONDRIAL BIOGENESIS AND ARSENICAL SKIN CARCINOGENESIS FOR THE FIRST TIME. HOWEVER, FURTHER MECHANISTIC STUDIES ARE NECESSARY FOR DETAILED UNDERSTANDING OF MITOCHONDRIA-NUCLEUS CROSSTALK IN ARSENIC PERTURBATION. 2020 10 1607 23 DNA METHYLATION, COLON CANCER AND MEDITERRANEAN DIET: RESULTS FROM THE EPIC-ITALY COHORT. THE BIOLOGICAL MECHANISMS THROUGH WHICH ADHERENCE TO MEDITERRANEAN DIET (MD) PROTECTS AGAINST COLON CANCER (CC) ARE POORLY UNDERSTOOD. EVIDENCE SUGGESTS THAT CHRONIC INFLAMMATION MAY BE IMPLICATED IN THE PATHWAY. BOTH DIET AND CC ARE RELATED TO EPIGENETIC REGULATION. WE PERFORMED A NESTED CASE-CONTROL STUDY ON 161 PAIRS FROM THE ITALIAN COMPONENT OF THE EUROPEAN PROSPECTIVE INVESTIGATION INTO CANCER AND NUTRITION (EPIC) COHORT, IN WHICH WE LOOKED FOR THE METHYLATION SIGNALS IN DNA EXTRACTED FROM LEUCOCYTES ASSOCIATED WITH BOTH CC AND MD IN 995 CPGS LOCATED IN 48 INFLAMMATION GENES. THE DNA METHYLATION SIGNALS DETECTED IN THIS ANALYSIS WERE VALIDATED IN A SUBGROUP OF 47 CASE-CONTROL PAIRS AND FURTHER REPLICATED (WHERE VALIDATED) IN 95 NEW PAIRS BY MEANS OF PYROSEQUENCING. AMONG THE CPG SITES SELECTED A-PRIORI IN INFLAMMATION-RELATED GENES, SEVEN CPG SITES WERE FOUND TO BE ASSOCIATED WITH CC STATUS AND WITH MD, IN LINE WITH ITS PROTECTIVE EFFECT. ONLY TWO CPG SITES (CG17968347-SERPINE1 AND CG20674490-RUNX3) WERE VALIDATED USING BISULPHITE PYROSEQUENCING AND, AFTER REPLICATION, WE FOUND THAT DNA METHYLATION OF CG20674490-RUNX3 MAY BE A POTENTIAL MOLECULAR MEDIATOR EXPLAINING THE PROTECTIVE EFFECT OF MD ON CC ONSET. THE USE OF A 'MEET-IN-THE-MIDDLE' APPROACH TO IDENTIFY THE OVERLAP BETWEEN EXPOSURE AND PREDICTIVE MARKERS OF DISEASE IS INNOVATIVE IN STUDIES ON THE RELATIONSHIP BETWEEN DIET AND CANCER, IN WHICH EXPOSURE ASSESSMENT IS DIFFICULT AND THE MECHANISMS THROUGH WHICH THE NUTRIENTS EXERT THEIR PROTECTIVE EFFECT IS LARGELY UNKNOWN. 2019 11 2714 31 EXERCISE-CONDITIONED PLASMA ATTENUATES NUCLEAR CONCENTRATIONS OF DNA METHYLTRANSFERASE 3B IN HUMAN PERIPHERAL BLOOD MONONUCLEAR CELLS. DNA METHYLATION IS MODIFIABLE BY ACUTE AND CHRONIC EXERCISE. DNA METHYLTRANSFERASES (DNMT) CATALYZE THIS PROCESS; HOWEVER, THERE IS A LACK OF LITERATURE CONCERNING THE SPECIFIC MECHANISMS BY WHICH EXERCISE-INDUCED MODIFICATIONS OCCUR. INTERLEUKIN 6 (IL-6) STIMULATION OF VARIOUS CELL LINES HAS BEEN SHOWN TO AUGMENT DNMT EXPRESSION AND NUCLEAR TRANSLOCATION, WHICH SUGGESTS A POSSIBLE PATHWAY BY WHICH EXERCISE IS ABLE TO ELICIT CHANGES IN EPIGENETIC ENZYMES. THE PRESENT STUDY SOUGHT TO ELUCIDATE THE RESPONSE OF THE DE NOVO METHYLTRANSFERASES DNMT3A AND DNMT3B TO CIRCULATORY FACTORS FOUND IN PLASMA ISOLATED FROM WHOLE BLOOD BEFORE AND AFTER 120-MIN OF TREADMILL RUNNING AT AN INTENSITY OF 60% OF INDIVIDUAL VELOCITY AT V O2MAX (VV O2MAX) INTERSPERSED WITH 30-SEC SPRINTS AT 90% OF VV O2MAX EVERY 10-MIN. PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) ISOLATED FROM A RESTING PARTICIPANT WERE INCUBATED WITH PLASMA ISOLATED FROM EXERCISING PARTICIPANTS (N = 10) OR RECOMBINANT IL-6 (RIL-6), FOLLOWED BY NUCLEAR PROTEIN EXTRACTION AND QUANTIFICATION OF DNMT3A AND DNMT3B CONCENTRATIONS. NUCLEAR CONCENTRATIONS OF DNMT3B SIGNIFICANTLY DECREASED FOLLOWING THE EXPERIMENTAL PROTOCOL (P = 0.03), WITH NO CHANGE OBSERVED IN DNMT3A (P = 0.514).VARIOUS CONCENTRATIONS OF RIL-6 CAUSED AN ELEVATION IN BOTH DNMT3A AND DNMT3B NUCLEAR CONCENTRATION COMPARED WITH THE BLANK CONTROL. THE CONFLICTING RESULTS BETWEEN EXERCISING AND RIL-6 CONDITIONS SUGGESTS THAT IL-6 DOES REGULATE DNMT NUCLEAR TRANSPORT, HOWEVER, OTHER PLASMA MEDIATORS MAY ALSO EXERT SIGNIFICANT INFLUENCE ON THE NUCLEAR CONCENTRATIONS OF THESE ENZYMES. 2015 12 1846 28 EFFECTS OF TWO TYPES OF ENERGY RESTRICTION ON METHYLATION LEVELS OF ADIPONECTIN RECEPTOR 1 AND LEPTIN RECEPTOR OVERLAPPING TRANSCRIPT IN A MOUSE MAMMARY TUMOUR VIRUS-TRANSFORMING GROWTH FACTOR-ALPHA BREAST CANCER MOUSE MODEL. THE ROLE OF ADIPONECTIN AND LEPTIN SIGNALLING PATHWAYS HAS BEEN SUGGESTED TO PLAY IMPORTANT ROLES IN THE PROTECTIVE EFFECTS OF ENERGY RESTRICTION (ER) ON MAMMARY TUMOUR (MT) DEVELOPMENT. TO STUDY THE EFFECTS OF ER ON THE METHYLATION LEVELS IN ADIPONECTIN RECEPTOR 1 (ADIPOR1) AND LEPTIN RECEPTOR OVERLAPPING TRANSCRIPT (LEPROT) GENES USING THE PYROSEQUENCING METHOD IN MAMMARY FAT PAD TISSUE, MOUSE MAMMARY TUMOUR VIRUS-TRANSFORMING GROWTH FACTOR-ALPHA (MMTV-TGF-ALPHA) FEMALE MICE WERE RANDOMLY ASSIGNED TO AD LIBITUM (AL), CHRONIC ER (CER, 15 % ER) OR INTERMITTENT ER (3 WEEKS AL AND 1 WEEK 60 % ER IN CYCLIC PERIODS) GROUPS AT 10 WEEKS OF AGE UNTIL 82 WEEKS OF AGE. THE METHYLATION LEVELS OF ADIPOR1 IN THE CER GROUP WERE HIGHER THAN THOSE IN THE AL GROUP AT WEEK 49/50 (P < 0.05), WHILE THE LEVELS OF METHYLATION FOR ADIPOR1 AND LEPROT GENES WERE SIMILAR AMONG THE OTHER GROUPS. ALSO, THE METHYLATION LEVELS AT CPG2 AND CPG3 REGIONS OF THE PROMOTER REGION OF THE ADIPOR1 GENE IN THE CER GROUP WERE THREE TIMES HIGHER (P < 0.05), WHILE CPG1 ISLAND OF LEPROT METHYLATION WAS SIGNIFICANTLY LOWER COMPARED WITH THE OTHER GROUPS (P < 0.05). ADIPONECTIN AND LEPTIN GENE EXPRESSION LEVELS WERE CONSISTENT WITH THE METHYLATION LEVELS. WE ALSO OBSERVED A CHANGE WITH AGEING IN METHYLATION LEVELS OF THESE GENES. THESE RESULTS INDICATE THAT DIFFERENT TYPES OF ER MODIFY METHYLATION LEVELS OF ADIPOR1 AND LEPROT IN DIFFERENT WAYS AND CER HAD A MORE SIGNIFICANT EFFECT ON METHYLATION LEVELS OF BOTH GENES. EPIGENETIC REGULATION OF THESE GENES MAY PLAY IMPORTANT ROLES IN THE PREVENTIVE EFFECTS OF ER AGAINST MT DEVELOPMENT AND AGEING PROCESSES. 2021 13 5841 22 STRUCTURAL CHROMATIN ALTERATIONS IN PERIPHERAL BLOOD LEUKOCYTES OF ALCOHOL-DEPENDENT INDIVIDUALS DURING DETOXIFICATION THERAPY. BACKGROUND/AIM: THE AIM OF THIS STUDY WAS TO INVESTIGATE THE STATE OF CHROMATIN CONDENSATION IN PERIPHERAL BLOOD LEUKOCYTES OF ALCOHOLICS, DURING THE EARLY DETOXIFICATION PERIOD, IN ORDER TO HIGHLIGHT STRUCTURAL MODIFICATIONS, INDICATING EPIGENETIC MECHANISMS REGULATED BY ALCOHOL. MATERIALS AND METHODS: BLOOD SAMPLES WERE OBTAINED FROM ALCOHOLIC PATIENTS, WHO WERE ADMITTED FOR DETOXIFICATION ON AN INPATIENT BASIS, AND FROM HEALTHY CONTROLS. THE LEVEL OF CONDENSED HETEROCHROMATIN AND DE-CONDENSED EUCHROMATIN WERE DETECTED THROUGH THE RATIO OF LYSINE TO ARGININE RESIDUES, BY THE APPLICATION OF THE AMMONIACAL SILVER REACTION (ASR) STAINING ON LEUKOCYTE PELLETS, AND THROUGH IMMUNOHISTOCHEMICAL LOCALIZATION OF HISTONE H1 ON PERIPHERAL BLOOD SMEARS. RESULTS: LYMPHOCYTES AND NEUTROPHILS WITH RELAXED DE-CONDENSED CHROMATIN WERE FOUND, INDICATING A MORE REACTIVE GENOME IN ALCOHOLICS, EVEN AT THE STAGE OF DETOXIFICATION. CONCLUSION: THE RESULTS UNDERLINE THE IMPORTANCE OF CHROMATIN STRUCTURE OF LEUKOCYTES AS A SENSITIVE, PERIPHERAL, BIOLOGICAL MARKER FOR EPIGENETIC STUDIES IN LIVING CHRONIC ALCOHOLICS. 2014 14 1193 33 CORRELATION OF CYP2R1 GENE PROMOTER METHYLATION WITH CIRCULATING VITAMIN D LEVELS AMONG HEALTHY ADULTS. BACKGROUND & OBJECTIVES: DESPITE BEING A TROPICAL COUNTRY, VITAMIN D DEFICIENCY IS HIGHLY PREVALENT IN INDIA WITH STUDIES INDICATING 40-99 PER CENT PREVALENCE. APART FROM CALCIUM AND PHOSPHATE METABOLISM, VITAMIN D IS INVOLVED IN CELL CYCLE REGULATION, CARDIOVASCULAR, HEPATOPROTECTION. THE METABOLISM OF VITAMIN D IS REGULATED BY VITAMIN D TOOL GENES (CYP2R1/CYP27B1/CYP24A1/VDR). THE PROMOTER REGIONS OF SOME OF THESE GENES HAVE CPG ISLANDS, MAKING THEM PRONE TO METHYLATION INDUCED GENE SILENCING, WHICH MAY CAUSE A REDUCTION IN CIRCULATING VITAMIN D LEVELS. EPIGENETIC BASIS OF VITAMIN D DEFICIENCY IS YET TO BE STUDIED IN INDIA, AND HENCE, THIS PILOT STUDY WAS AIMED TO ANALYZE WHETHER METHYLATION LEVELS OF CYP2R1 GENE WERE CORRELATED WITH THE LEVELS OF 25(OH)D IN HEALTHY, ADULT INDIVIDUALS IN INDIAN POPULATION. METHODS: IN THIS CROSS-SECTIONAL STUDY, HEALTHY ADULTS OF 18-45 YR OF AGE WITH NO HISTORY OF MALABSORPTION, THYROIDECTOMY, CHRONIC ILLNESS OR THERAPEUTIC VITAMIN D SUPPLEMENTATION WERE RECRUITED. DNA METHYLATION ANALYSIS WAS CARRIED OUT BY METHYLATION SPECIFIC QUANTITATIVE PCR. SERUM CALCIUM, PHOSPHATE AND VITAMIN D LEVELS WERE ALSO QUANTIFIED. STATISTICAL ANALYSIS WAS DONE BY R 4.0.5 SOFTWARE. RESULTS: A TOTAL OF 61 APPARENTLY HEALTHY ADULTS WERE ANALYZED. THE SERUM VITAMIN D LEVELS DID NOT CORRELATE WITH CYP2R1 METHYLATION LEVELS IN OUR STUDY POPULATION. SIGNIFICANT POSITIVE CORRELATION WAS OBSERVED BETWEEN AGE AND SERUM VITAMIN D LEVELS. SIGNIFICANT ASSOCIATION OF GENDER WAS FOUND WITH CYP2R1 METHYLATION LEVELS. INTERPRETATION & CONCLUSIONS: THIS STUDY FOUND NO SIGNIFICANT CORRELATION BETWEEN LEVELS OF CYP2R1 METHYLATION AND CIRCULATING 25(OH)D DEFICIENCY. FURTHER STUDIES ON THE INDIAN POPULATION HAVING A LARGER SAMPLE SIZE INCLUDING ENTIRE VITAMIN D TOOL GENES, AMONG DIFFERENT ETHNIC GROUPS MAY BE CONDUCTED TO ELUCIDATE MOLECULAR ETIOLOGY OF CIRCULATING 25(OH)D DEFICIENCY. THE HIGH PREVALENCE OF NORMAL SERUM CALCIUM AND PHOSPHATE LEVELS AMONG VITAMIN D DEFICIENT SUBJECTS IN THIS STUDY COUPLED WITH THE STRIKINGLY HIGH PREVALENCE OF THE DEFICIENCY AT THE NATIONAL LEVEL, MAY SUGGEST THE NEED TO REVISE THE CUT-OFF CRITERIA FOR VITAMIN D DEFICIENCY IN THE INDIAN POPULATION. 2023 15 3125 19 GHSR DNA HYPERMETHYLATION IS A COMMON EPIGENETIC ALTERATION OF HIGH DIAGNOSTIC VALUE IN A BROAD SPECTRUM OF CANCERS. IDENTIFICATION OF A SINGLE MOLECULAR TRAIT THAT IS DETERMINANT OF COMMON MALIGNANCIES MAY SERVE AS A POWERFUL DIAGNOSTIC SUPPLEMENT TO CANCER TYPE-SPECIFIC MARKERS. HERE, WE REPORT A DNA METHYLATION MARK THAT IS CHARACTERISTIC OF SEVEN STUDIED MALIGNANCIES, NAMELY CANCERS OF LUNG, BREAST, PROSTATE, PANCREAS, COLORECTUM, GLIOBLASTOMA AND B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) (N = 137). THIS MARK WAS DEFINED BY SUBSTANTIAL HYPERMETHYLATION AT THE PROMOTER AND FIRST EXON OF GROWTH HORMONE SECRETAGOUGE RECEPTOR (GHSR) THROUGH BISULFITE PYROSEQUENCING. THE DEGREE OF ABERRANT METHYLATION WAS CAPABLE OF ACCURATE DISCRIMINATION BETWEEN CANCER AND CONTROL SAMPLES. THE HIGHEST SENSITIVITY AND SPECIFICITY OF CANCER DETECTION WAS ACHIEVED FOR CANCERS OF PANCREAS, LUNG, BREAST AND CLL YIELDING THE AREA UNDER THE CURVE (AUC) VALUES OF 1.0000, 0.9952, 0.9800 AND 0.9400, RESPECTIVELY. NARROWING TO A SINGLE CPG SITE WITHIN THE GENE'S PROMOTER OR FOUR CONSECUTIVE CPG UNITS OF THE HIGHEST METHYLATION LEVELS WITHIN THE FIRST EXON IMPROVED THE DETECTION POWER. GHSR HYPERMETHYLATION WAS DETECTED ALREADY AT THE EARLY STAGE TUMORS. THE ACCURATE PERFORMANCE OF THIS MARKER WAS FURTHER REPLICATED IN AN INDEPENDENT SET OF PANCREATIC CANCER AND CONTROL SAMPLES (N = 78). THESE FINDINGS SUPPORT THE CANDIDATURE OF GHSR METHYLATION AS A HIGHLY ACCURATE PAN-CANCER MARKER. 2015 16 1144 26 CONCOMITANT HETEROCHROMATINISATION AND DOWN-REGULATION OF GENE EXPRESSION UNVEILS EPIGENETIC SILENCING OF RELB IN AN AGGRESSIVE SUBSET OF CHRONIC LYMPHOCYTIC LEUKEMIA IN MALES. BACKGROUND: THE SENSITIVITY OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS TO CURRENT TREATMENTS, BOTH IN VITRO AND IN VIVO, RELIES ON THEIR ABILITY TO ACTIVATE APOPTOTIC DEATH. CLL CELLS RESISTANT TO DNA DAMAGE-INDUCED APOPTOSIS DISPLAY DEREGULATION OF A SPECIFIC SET OF GENES. METHODS: MICROARRAY HYBRIDIZATION (HUMAN GENECHIP, AFFYMETRIX), IMMUNOFLUORESCENT IN SITU LABELING COUPLED WITH VIDEO-MICROSCOPY RECORDING/ANALYSES, CHROMATIN-IMMUNOPRECIPITATION (CHIP), POLYMERASE CHAIN REACTIONS (PCR), REAL-TIME QUANTITATIVE PCR (RT-QPCR) AND BISULFITE GENOME SEQUENCING WERE THE MAIN METHODS APPLIED. STATISTICAL ANALYSES WERE PERFORMED BY APPLYING GCRMA AND SAM ANALYSIS (MICROARRAY DATA) AND STUDENT'S T-TEST OR MANN & WHITNEY'S U-TEST. RESULTS: HEREIN WE SHOW THAT, REMARKABLY, IN A RESISTANT MALE CLL CELLS THE VAST MAJORITY OF GENES WERE DOWN-REGULATED COMPARED WITH SENSITIVE CELLS, WHEREAS THIS WAS NOT THE CASE IN CELLS DERIVED FROM FEMALES. THIS GENE DOWN-REGULATION WAS FOUND TO BE ASSOCIATED WITH AN OVERALL GAIN OF HETEROCHROMATIN AS EVIDENCED BY IMMUNOFLUORESCENT LABELING OF HETEROCHROMATIN PROTEIN 1ALPHA (HP-1), TRIMETHYLATED HISTONE 3 LYSINE 9 (3METH3K9), AND 5-METHYLCYTIDINE (5METC). NOTABLY, 17 GENES WERE FOUND TO BE COMMONLY DEREGULATED IN RESISTANT MALE AND FEMALE CELL SAMPLES. AMONG THESE, RELB WAS IDENTIFIED AS A DISCRIMINATORY CANDIDATE GENE REPRESSED IN THE MALE AND UPREGULATED IN THE FEMALE RESISTANT CELLS. CONCLUSION: THE MOLECULAR DEFECTS IN THE SILENCING OF RELB INVOLVE AN INCREASE IN H3K9- BUT NOT CPG-ISLAND METHYLATION IN THE PROMOTER REGIONS. INCREASE IN ACETYL-H3 IN RESISTANT FEMALE BUT NOT MALE CLL SAMPLES AS WELL AS A DECREASE OF TOTAL CELLULAR LEVEL OF RELB AFTER AN INHIBITION OF HISTONE DEACETYLASE (HDAC) BY TRICHOSTATIN A (TSA), FURTHER EMPHASIZE THE ROLE OF EPIGENETIC MODIFICATIONS WHICH COULD DISCRIMINATE TWO CLL SUBSETS. TOGETHER, THESE RESULTS HIGHLIGHTED THE EPIGENETIC RELB SILENCING AS A NEW MARKER OF THE PROGRESSIVE DISEASE IN MALES. 2010 17 2297 33 EPIGENETIC REGULATION OF ACUTE INFLAMMATORY PAIN. ACUTE PAIN IS ASSOCIATED WITH TISSUE DAMAGE, WHICH RESULTS IN THE RELEASE OF INFLAMMATORY MEDIATORS. RECENT STUDIES POINT TO THE INVOLVEMENT OF EPIGENETIC MECHANISMS (DNA METHYLATION) IN THE DEVELOPMENT OF PAIN. WE HAVE FOUND THAT DURING ACUTE INFLAMMATORY PAIN INDUCED BY THE APPLICATION OF 10% MUSTARD OIL ON THE TONGUES OF RATS, LEVELS OF DNMT3A AND 3B WERE ELEVATED MARKEDLY (36 AND 42 % RESPECTIVELY), WHEREAS THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY. PREVIOUS INJECTION OF XEFOCAM WITH 0,4 MG/KG DOSE DECREASED LEVELS OF DNMT3A AND 3B (25 AND 24% RESPECTIVELY). THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY COMPARED TO THE CONTROL GROUP. THE FINDINGS SUPPORT THE IDEA THAT INHIBITORS OF DNA-METHYLTRANSFERASES COULD BE USEFUL FOR PAIN MANAGEMENT. OUR DATA SUGGEST THAT NSAIDS (ALONE OR IN COMBINATION WITH DNMT INHIBITORS) MAY BE PROPOSED AS POSSIBLE EPIGENETIC REGULATORY AGENTS, WHICH MAY PLAY A ROLE IN EPIGENETIC MECHANISMS INDIRECTLY THROUGH ALTERING THE ACTIVITY OF INFLAMMATORY MEDIATORS INVOLVED IN PAIN DEVELOPMENT. 2014 18 2921 27 GENE-SPECIFIC DIFFERENTIAL DNA METHYLATION AND CHRONIC ARSENIC EXPOSURE IN AN EPIGENOME-WIDE ASSOCIATION STUDY OF ADULTS IN BANGLADESH. BACKGROUND: INORGANIC ARSENIC IS ONE OF THE MOST COMMON NATURALLY OCCURRING CONTAMINANTS FOUND IN THE ENVIRONMENT. ARSENIC IS ASSOCIATED WITH A NUMBER OF HEALTH OUTCOMES, WITH EPIGENETIC MODIFICATION SUGGESTED AS A POTENTIAL MECHANISM OF TOXICITY. OBJECTIVE: AMONG A SAMPLE OF 400 ADULT PARTICIPANTS, WE EVALUATED THE ASSOCIATION BETWEEN ARSENIC EXPOSURE, AS MEASURED BY BLOOD AND URINARY TOTAL ARSENIC CONCENTRATIONS, AND EPIGENOME-WIDE WHITE BLOOD CELL DNA METHYLATION. METHODS: WE USED LINEAR REGRESSION MODELS TO EXAMINE THE ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND METHYLATION AT EACH CPG SITE, ADJUSTED FOR SEX, AGE, AND BATCH. DIFFERENTIALLY METHYLATED LOCI WERE SUBSEQUENTLY EXAMINED IN RELATION TO CORRESPONDING GENE EXPRESSION FOR FUNCTIONAL EVIDENCE OF GENE REGULATION. RESULTS: IN ADJUSTED ANALYSES, WE OBSERVED FOUR DIFFERENTIALLY METHYLATED CPG SITES WITH URINARY TOTAL ARSENIC CONCENTRATION AND THREE DIFFERENTIALLY METHYLATED CPG SITES WITH BLOOD ARSENIC CONCENTRATION, BASED ON THE BONFERRONI-CORRECTED SIGNIFICANCE THRESHOLD OF P < 1 X 10(-7). METHYLATION OF PLA2G2C (PROBE CG04605617) WAS THE MOST SIGNIFICANTLY ASSOCIATED LOCUS IN RELATION TO BOTH URINARY (P = 3.40 X 10(-11)) AND BLOOD ARSENIC CONCENTRATIONS (P = 1.48 X 10(-11)). THREE ADDITIONAL NOVEL METHYLATION LOCI-SQSTM1 (CG01225779), SLC4A4 (CG06121226), AND IGH (CG13651690)--WERE ALSO SIGNIFICANTLY ASSOCIATED WITH ARSENIC EXPOSURE. FURTHER, THERE WAS EVIDENCE OF METHYLATION-RELATED GENE REGULATION BASED ON GENE EXPRESSION FOR A SUBSET OF DIFFERENTIALLY METHYLATED LOCI. CONCLUSIONS: WE OBSERVED SIGNIFICANT ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND GENE-SPECIFIC DIFFERENTIAL WHITE BLOOD CELL DNA METHYLATION, SUGGESTING THAT EPIGENETIC MODIFICATIONS MAY BE AN IMPORTANT PATHWAY UNDERLYING ARSENIC TOXICITY. THE SPECIFIC DIFFERENTIALLY METHYLATED LOCI IDENTIFIED MAY INFORM POTENTIAL PATHWAYS FOR FUTURE INTERVENTIONS. 2015 19 1729 28 DYSREGULATION OF MIR-155 EXPRESSION IN PROFESSIONAL MIXED MARTIAL ARTS (MMA) FIGHTERS. PSYCHOLOGICAL AND PHYSICAL STRESS CAN INDUCE DYSREGULATION OF GENE EXPRESSION VIA CHANGES IN DNA METHYLATION AND MICRORNA (MIRNA) EXPRESSION. SUCH EPIGENETIC MODIFICATIONS ARE YET TO BE INVESTIGATED IN PROFESSIONAL MIXED MARTIAL ARTS (MMA) FIGHTERS SUBJECT TO HIGHLY STRESSFUL TRAINING INVOLVING REPETITIVE HEAD IMPACTS. THIS STUDY EXAMINED DIFFERENCES IN DNA METHYLATION AND MIRNA EXPRESSION IN ELITE MMA FIGHTERS COMPARED TO ACTIVE CONTROLS. GLOBAL METHYLATION DIFFERENCES BETWEEN GROUPS WERE ASSESSED VIA A LINE-1 ASSAY. AT THE SAME TIME, PCR ARRAYS WERE USED TO ESTIMATE DIFFERENTIAL EXPRESSION IN SAMPLES OF 21 FIGHTERS AND 15 CONTROLS FOR 192 DIFFERENT MIRNAS ASSOCIATED WITH INFLAMMATORY DISEASES. AN INDEPENDENT-SAMPLES T-TEST FOUND NO SIGNIFICANT DIFFERENCE IN LINE-1 METHYLATION BETWEEN GROUPS. HOWEVER, AN INDEPENDENT-SAMPLES MANN-WHITNEY U TEST REVEALED A SIGNIFICANT UPREGULATION IN THE EXPRESSION OF MIR-155 IN MMA FIGHTER PLASMA. SINCE MIR-155 HAS BEEN RECOGNIZED AS AN IMPORTANT REGULATOR OF NEUROINFLAMMATION, THIS DYSREGULATION SUGGESTS A POSSIBLE EPIGENETIC MECHANISM RESPONSIBLE FOR CHRONIC INFLAMMATION ASSOCIATED WITH PROFESSIONAL-LEVEL MMA TRAINING. CONSISTENT WITH OTHER PUBLISHED WORKS, THIS STUDY HIGHLIGHTS THE POTENTIAL OF MIR-155 NOT ONLY AS A BIOMARKER FOR MONITORING LONG-TERM HEALTH RISKS LINKED TO HEAD TRAUMA BUT ALSO AS A TARGET TO REMEDIATE THE IMPACT OF CHRONIC NEUROINFLAMMATION. 2023 20 1117 24 COMPARATIVE AND EXPERIMENTAL STUDIES ON THE GENES ALTERED BY CHRONIC HYPOXIA IN HUMAN BRAIN MICROENDOTHELIAL CELLS. BACKGROUND : HYPOXIA INDUCIBLE FACTOR 1 ALPHA (HIF1A) IS A MASTER REGULATOR OF ACUTE HYPOXIA; HOWEVER, WITH CHRONIC HYPOXIA, HIF1A LEVELS RETURN TO THE NORMOXIC LEVELS. IMPORTANTLY, THE GENES THAT ARE INVOLVED IN THE CELL SURVIVAL AND VIABILITY UNDER CHRONIC HYPOXIA ARE NOT KNOWN. THEREFORE, WE TESTED THE HYPOTHESIS THAT CHRONIC HYPOXIA LEADS TO THE UPREGULATION OF A CORE GROUP OF GENES WITH ASSOCIATED CHANGES IN THE PROMOTER DNA METHYLATION THAT MEDIATES THE CELL SURVIVAL UNDER HYPOXIA. RESULTS : WE EXAMINED THE EFFECT OF CHRONIC HYPOXIA (3 DAYS; 0.5% OXYGEN) ON HUMAN BRAIN MICRO ENDOTHELIAL CELLS (HBMEC) VIABILITY AND APOPTOSIS. HYPOXIA CAUSED A SIGNIFICANT REDUCTION IN CELL VIABILITY AND AN INCREASE IN APOPTOSIS. NEXT, WE EXAMINED CHRONIC HYPOXIA ASSOCIATED CHANGES IN TRANSCRIPTOME AND GENOME-WIDE PROMOTER METHYLATION. THE DATA OBTAINED WAS COMPARED WITH 16 OTHER MICROARRAY STUDIES ON CHRONIC HYPOXIA. NINE GENES WERE ALTERED IN RESPONSE TO CHRONIC HYPOXIA IN ALL 17 STUDIES. INTERESTINGLY, HIF1A WAS NOT ALTERED WITH CHRONIC HYPOXIA IN ANY OF THE STUDIES. FURTHERMORE, WE COMPARED OUR DATA TO THREE OTHER STUDIES THAT IDENTIFIED HIF-RESPONSIVE GENES BY VARIOUS APPROACHES. ONLY TWO GENES WERE FOUND TO BE HIF DEPENDENT. WE SILENCED EACH OF THESE 9 GENES USING CRISPR/CAS9 SYSTEM. DOWNREGULATION OF EGLN3 SIGNIFICANTLY INCREASED THE CELL DEATH UNDER CHRONIC HYPOXIA, WHEREAS DOWNREGULATION OF ERO1L, ENO2, ADRENOMEDULLIN, AND SPAG4 REDUCED THE CELL DEATH UNDER HYPOXIA. CONCLUSIONS : WE PROVIDE A CORE GROUP OF GENES THAT REGULATES CELLULAR ACCLIMATIZATION UNDER CHRONIC HYPOXIC STRESS, AND MOST OF THEM ARE HIF INDEPENDENT. 2017