1 5184 114 PREMATURE CHROMOSOME CONDENSATION ASSAY TO STUDY INFLUENCE OF HIGH-LEVEL NATURAL RADIATION ON THE INITIAL DNA DOUBLE STRAND BREAK REPAIR IN HUMAN G(0) LYMPHOCYTES. THE INHERENT CAPACITY OF INDIVIDUALS TO EFFICIENTLY REPAIR IONIZING RADIATION INDUCED DNA DOUBLE STRAND BREAKS (DSBS) MAY BE INHERITED, HOWEVER, IT IS INFLUENCED BY SEVERAL EPIGENETIC AND ENVIRONMENTAL FACTORS. A PILOT STUDY TESTED WHETHER CHRONIC LOW DOSE NATURAL RADIATION EXPOSURE INFLUENCES THE REJOINING OF INITIAL DNA DSBS INDUCED BY A 2 GY GAMMA-IRRADIATION IN 22 INDIVIDUALS FROM HIGH (>1.5 MGY/YEAR) AND NORMAL ( 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 14 3657 33 INDUCTION AND RECOVERY OF CPG SITE SPECIFIC METHYLATION CHANGES IN HUMAN BRONCHIAL CELLS AFTER LONG-TERM EXPOSURE TO CARBON NANOTUBES AND ASBESTOS. INTRODUCTION: INHALATION OF ASBESTOS INDUCES LUNG CANCER VIA DIFFERENT CELLULAR MECHANISMS. TOGETHER WITH THE INCREASED PRODUCTION OF CARBON NANOTUBES (CNTS) GROWS THE CONCERN ABOUT ADVERSE EFFECTS ON THE LUNGS GIVEN THE SIMILARITIES WITH ASBESTOS. WHILE IT HAS BEEN ESTABLISHED THAT CNT AND ASBESTOS INDUCE EPIGENETIC ALTERATIONS, IT IS CURRENTLY NOT KNOWN WHETHER ALTERATIONS AT EPIGENETIC LEVEL REMAIN STABLE AFTER WITHDRAWAL OF THE EXPOSURE. IDENTIFICATION OF DNA METHYLATION CHANGES AFTER A LOW DOSE OF CNT AND ASBESTOS EXPOSURE AND RECOVERY CAN BE USEFUL TO DETERMINE THE FIBRE/PARTICLE TOXICITY AND ADVERSE OUTCOME. METHODS: HUMAN BRONCHIAL EPITHELIAL CELLS (16HBE) WERE TREATED WITH A LOW AND NON-CYTOTOXIC DOSE (0.25 MICROG/ML) OF MULTI-WALLED CARBON NANOTUBES (MWCNTS-NM400) OR SINGLE-WALLED CARBON NANOTUBES (SWCNTS-SRM2483) AND 0.05 MICROG/ML AMOSITE (BROWN) ASBESTOS FOR THE COURSE OF FOUR WEEKS (SUB-CHRONIC EXPOSURE). AFTER THIS TREATMENT, THE CELLS WERE FURTHER INCUBATED (WITHOUT PARTICLE/FIBRE) FOR TWO WEEKS, ALLOWING RECOVERY FROM THE EXPOSURE (RECOVERY PERIOD). NUCLEAR DEPOSITIONS OF THE CNTS WERE ASSESSED USING FEMTOSECOND PULSED LASER MICROSCOPY IN A LABEL-FREE MANNER. DNA METHYLATION ALTERATIONS WERE ANALYSED USING MICROARRAYS THAT ASSESS MORE THAN 850 THOUSAND CPG SITES IN THE WHOLE GENOME. RESULTS: AT NON-CYTOTOXIC DOSES, CNTS WERE NOTED TO BE INCORPORATED WITH IN THE NUCLEUS AFTER A FOUR WEEKS PERIOD. EXPOSURE TO MWCNTS INDUCED A SINGLE HYPOMETHYLATION AT A CPG SITE AND GENE PROMOTER REGION. NO CHANGE IN DNA METHYLATION WAS OBSERVED AFTER THE RECOVERY PERIOD FOR MWCNTS. EXPOSURE TO SWCNTS OR AMOSITE INDUCED HYPERMETHYLATION AT CPG SITES AFTER SUB-CHRONIC EXPOSURE WHICH MAY INVOLVE IN 'TRANSCRIPTION FACTOR ACTIVITY' AND 'SEQUENCE-SPECIFIC DNA BINDING' GENE ONTOLOGIES. AFTER THE RECOVERY PERIOD, HYPERMETHYLATION AND HYPOMETHYLATION WERE NOTED FOR BOTH SWCNTS AND AMOSITE. HIPPOCALCINLIKE 1 (HPCAL1), PROTEASE SERINE 3 (PRSS3), KALLIKREIN-RELATED PEPTIDASE 3 (KLK3), KRUPPEL LIKE FACTOR 3 (KLF3) GENES WERE HYPERMETHYLATED AT DIFFERENT TIME POINTS IN EITHER SWCNT-EXPOSED OR AMOSITE-EXPOSED CELLS. CONCLUSION: THESE RESULTS SUGGEST THAT THE SPECIFIC SWCNT (SRM2483) AND AMOSITE FIBRES STUDIED INDUCE HYPO- OR HYPERMETHYLATION ON CPG SITES IN DNA AFTER VERY LOW-DOSE EXPOSURE AND RECOVERY PERIOD. THIS EFFECT WAS NOT SEEN FOR THE STUDIED MWCNT (NM400). 2020 15 3718 25 INHIBITION OF BCL6B PROMOTES GASTRIC CANCER BY AMPLIFYING INFLAMMATION IN MICE. BACKGROUND: CHRONIC GASTRITIS HAS BEEN DEMONSTRATED TO BE A KEY CAUSE OF GASTRIC CANCER (GC), AND CONTROL OF GASTRIC INFLAMMATION IS REGARDED AS AN EFFECTIVE TREATMENT FOR THE CLINICAL PREVENTION OF GASTRIC CARCINOGENESIS. HOWEVER, THERE REMAINS AN UNMET NEED TO IDENTIFY THE DOMINANT REGULATORS OF GASTRIC ONCOGENESIS-ASSOCIATED INFLAMMATION IN VIVO. METHODS: THE MOUSE MODEL FOR THE STUDY OF INFLAMMATION-ASSOCIATED GC WAS INDUCED BY BENZO[A]PYRENE (BAP) INTRAGASTRIC ADMINISTRATION IN BCL6B(-/-) AND WILDTYPE MICE ON A C57BL/6 BACKGROUND. 5-AZA-2'-DEOXYCYTIDINE (5-AZA), THE DEMETHYLATION DRUG, WAS INTRAPERITONEALLY INJECTED TO RESTORE BCL6B EXPRESSION. HUMAN GC TISSUE ARRAY WAS USED TO ANALYSE PATIENT SURVIVAL BASED ON BCL6B AND CD3 PROTEIN EXPRESSION. RESULTS: BCL6B WAS GRADUALLY DOWNREGULATED BY ITS OWN PROMOTER HYPERMETHYLATION IN PARALLEL TO AN INCREASING INFLAMMATORY RESPONSE DURING THE PROGRESSION OF BAP-INDUCED GASTRIC CARCINOGENESIS IN MICE. MOREOVER, KNOCKOUT OF BCL6B DRAMATICALLY WORSENED THE SEVERITY OF GASTRIC CANCER AND AGGRAVATED THE INFLAMMATORY RESPONSE IN THE BAP-INDUCED MICE GC MODEL. RE-ACTIVATION OF BCL6B BY 5-AZA IMPEDED INFLAMMATORY AMPLIFICATION AND BAP-INDUCED GC DEVELOPMENT, PROLONGING SURVIVAL TIME IN WILDTYPE MICE, WHEREAS NO NOTABLE CURATIVE EFFECT OCCURRED IN BCL6B(-/-) MICE WITH 5-AZA TREATMENT. FINALLY, SIGNIFICANT NEGATIVE CORRELATIONS WERE DETECTED BETWEEN THE MRNA LEVELS OF BCL6B AND INFLAMMATORY CYTOKINES IN HUMAN GC TISSUES; PATIENTS HARBOURING BCL6B-NEGETIVE AND SEVERE-INFLAMMATION GC TUMOURS WERE FOUND TO EXHIBIT THE SHORTEST SURVIVAL TIME. CONCLUSIONS: EPIGENETIC INACTIVATION OF BCL6B PROMOTES GASTRIC CANCER THROUGH AMPLIFICATION OF THE GASTRIC INFLAMMATORY RESPONSE IN VIVO AND OFFERS A NEW APPROACH FOR GC TREATMENT AND REGENERATIVE MEDICINE. 2019 16 6777 14 [ASSOCIATION OF P-MOBILE ELEMENT ACTIVITY AND DNA METHYLATION PATTERN CHANGES IN THE CONDITIONS OF DROSOPHILA MELANOGASTER PROLONGED IRRADIATION]. ASSOCIATION OF THE RADIOSENSITIVITY AND EPIGENETIC PATTERN DNA CHANGES AT THE CONDITIONS OF PROLONGED IRRADIATION WAS INVESTIGATED. TWO LABORATORY DROSOPHILA MELANOGASTER STRAINS (CANTON-S AND RI) IRRADIATED FOR 20 GENERATIONS TO LOW DOSES RATE (1.2 X 10(-1), 0.8 X 10(-8) AND 0.12 X 10(-8) GY/S) WERE USED AS EXPERIMENTAL OBJECTS. DNA FOR THE ANALYSIS WAS EXTRACTED SEPARATELY FOR THE FLIES OF MALES AND FEMALES. RESTRICTION ENDONUCLEASES GLUL, GLAL WERE USED. RESTRICTION ANALYSIS HAS SHOWN THAT THERE ARE DIFFERENT DNA METHYLATED PATTERNS FOR MALES AND FEMALES AS FOR CONTROL AND EXPOSED VARIANTS. AT THE CHRONIC IRRADIATION THERE WAS THE DECLINE OF METHYLATION LEVEL AT THE ENZYMES GLUL, GLAL SITES RECOGNITION. 2010 17 491 28 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 18 2763 23 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS. 2010 19 3074 25 GENOME-WIDE DNA METHYLOME AND TRANSCRIPTOME CHANGES INDUCED BY INORGANIC NANOPARTICLES IN HUMAN KIDNEY CELLS AFTER CHRONIC EXPOSURE. THE UNIQUE PHYSICOCHEMICAL PROPERTIES MAKE INORGANIC NANOPARTICLES (INPS) AN EXCITING TOOL IN DIAGNOSIS AND DISEASE MANAGEMENT. HOWEVER, AS INPS ARE RELATIVELY DIFFICULT TO FULLY DEGRADE AND EXCRETE, THEIR UNINTENDED ACCUMULATION IN THE TISSUE MIGHT RESULT IN ADVERSE HEALTH EFFECTS. HEREIN, WE PROVIDE A METHYLOME-TRANSCRIPTOME FRAMEWORK FOR CHRONIC EFFECTS OF INPS, COMMONLY USED IN BIOMEDICAL APPLICATIONS, IN HUMAN KIDNEY TH-1 CELLS. RENAL CLEARANCE IS ONE OF THE MOST IMPORTANT ROUTES OF NANOPARTICLE EXCRETION; THEREFORE, A DETAILED EVALUATION OF NANOPARTICLE-MEDIATED NEPHROTOXICITY IS AN IMPORTANT TASK. INTEGRATED ANALYSIS OF METHYLOME AND TRANSCRIPTOME CHANGES INDUCED BY INPS (PEG-AUNPS, FE(3)O(4)NPS, SIO(2)NPS, AND TIO(2)NPS) REVEALED SIGNIFICANTLY DEREGULATED GENES WITH FUNCTIONAL CLASSIFICATION IN IMMUNE RESPONSE, DNA DAMAGE, AND CANCER-RELATED PATHWAYS. ALTHOUGH MOST DEREGULATED GENES WERE UNIQUE TO INDIVIDUAL INPS, A RELATIVELY HIGH PROPORTION OF THEM ENCODED THE TRANSCRIPTION FACTORS. INTERESTINGLY, FOS HYPERMETHYLATION INVERSELY CORRELATING WITH GENE EXPRESSION WAS ASSOCIATED WITH ALL INPS EXPOSURES. OUR STUDY EMPHASIZES THE NEED FOR A MORE COMPREHENSIVE INVESTIGATION OF INPS' BIOLOGICAL SAFETY, ESPECIALLY AFTER CHRONIC EXPOSURE. 2022 20 136 25 ABERRANT DNA HYPERMETHYLATION PATTERNS LEAD TO TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS OF MICE. OVEREXPOSURE OF THE HUMAN SKIN TO SOLAR ULTRAVIOLET (UV) RADIATION IS THE MAJOR ETIOLOGIC FACTOR FOR DEVELOPMENT OF SKIN CANCERS. HERE, WE REPORT THE RESULTS OF EPIGENETIC MODIFICATIONS IN UV-EXPOSED SKIN AND SKIN TUMORS IN A SYSTEMATIC MANNER. THE SKIN AND TUMOR SAMPLES WERE COLLECTED AFTER CHRONIC EXPOSURE OF THE SKIN OF SKH-1 HAIRLESS MICE TO UVB RADIATION USING A WELL-ESTABLISHED PHOTOCARCINOGENESIS PROTOCOL. WE FOUND A DISTINCT DNA HYPERMETHYLATION PATTERN IN THE UVB-EXPOSED EPIDERMAL SKIN AND UVB-INDUCED SKIN TUMORS THAT WAS ASSOCIATED WITH THE ELEVATED EXPRESSION AND ACTIVITY OF THE DNA METHYLTRANSFERASES (DNMT) 1, DNMT3A AND DNMT3B. TO EXPLORE THE ROLE OF HYPERMETHYLATION IN SKIN PHOTOCARCINOGENESIS, WE FOCUSED ON THE P16(INK4A) AND RASSF1A TUMOR SUPPRESSOR GENES, WHICH ARE TRANSCRIPTIONALLY SILENCED ON METHYLATION. WE ESTABLISHED THAT THE SILENCING OF THESE GENES IN UVB-EXPOSED EPIDERMIS AND UVB-INDUCED SKIN TUMORS IS ASSOCIATED WITH A NETWORK OF EPIGENETIC MODIFICATIONS, INCLUDING HYPOACETYLATION OF HISTONE H3 AND H4 AND INCREASED HISTONE DEACETYLATION, AS WELL AS RECRUITMENT OF METHYL-BINDING PROTEINS, INCLUDING MECP2 AND MBD1, TO THE METHYLATED CPGS. HIGHER LEVELS OF DNA METHYLATION AND DNMT ACTIVITY IN HUMAN SQUAMOUS CELL CARCINOMA SPECIMENS THAN IN NORMAL HUMAN SKIN SUGGEST THAT THE DATA ARE RELEVANT CLINICALLY. OUR DATA INDICATE FOR THE FIRST TIME THAT UVB-INDUCED DNA HYPERMETHYLATION, ENHANCED DNMT ACTIVITY AND HISTONE MODIFICATIONS OCCUR IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS AND SUGGEST THAT THESE EVENTS ARE INVOLVED IN THE SILENCING OF TUMOR SUPPRESSOR GENES AND IN SKIN TUMOR DEVELOPMENT. 2011