1 1948 197 EPIGENETIC ACQUISITION OF INDUCIBILITY OF TYPE III CYTOTOXICITY IN P. AERUGINOSA. BACKGROUND: PSEUDOMONAS AERUGINOSA, AN OPPORTUNISTIC PATHOGEN, IS OFTEN ENCOUNTERED IN CHRONIC LUNG DISEASES SUCH AS CYSTIC FIBROSIS OR CHRONIC OBSTRUCTIVE PNEUMONIA, AS WELL AS ACUTE SETTINGS LIKE MECHANICAL VENTILATION ACQUIRED PNEUMONIA OR NEUTROPENIC PATIENTS. IT IS A MAJOR CAUSE OF MORTALITY AND MORBIDITY IN THESE DISEASES. IN LUNGS, P. AERUGINOSA SETTLES IN A BIOFILM MODE OF GROWTH WITH THE SECRETION OF EXOPOLYSACCHARIDES IN WHICH IT IS ENCAPSULATED, ENHANCING ITS ANTIBIOTIC RESISTANCE AND CONTRIBUTING TO THE RESPIRATORY DEFICIENCY OF PATIENTS. HOWEVER, BACTERIA MUST FIRST MULTIPLY TO A HIGH DENSITY AND DISPLAY A CYTOTOXIC PHENOTYPE TO AVOID THE HOST'S DEFENCES. A VIRULENCE DETERMINANT IMPLICATED IN THIS STEP OF INFECTION IS THE TYPE III SECRETION SYSTEM (TTSS), ALLOWING TOXIN INJECTION DIRECTLY INTO HOST CELLS. AT THE BEGINNING OF THE INFECTION, MOST STRAINS ISOLATED FROM PATIENTS' LUNGS POSSESS AN INDUCIBLE TTSS ALLOWING TOXINS INJECTION OR SECRETION UPON IN VIVO OR IN VITRO ACTIVATION SIGNALS. AS THE INFECTION PERSISTS MOST OF THE BACTERIA PERMANENTLY LOOSE THIS CAPACITY, ALTHOUGH NO MUTATIONS HAVE BEEN EVIDENCED. WE NAME "NON INDUCIBLE" THIS PHENOTYPE. AS SUGGESTED BY THE PRESENCE OF A POSITIVE FEEDBACK CIRCUIT IN THE REGULATORY NETWORK CONTROLLING TTSS EXPRESSION, IT MAY BE DUE TO AN EPIGENETIC SWITCH ALLOWING HERITABLE PHENOTYPIC MODIFICATIONS WITHOUT GENOTYPE'S MUTATIONS. RESULTS: USING THE GENERALISED LOGICAL METHOD, WE DESIGNED A MINIMAL MODEL OF THE TTSS REGULATORY NETWORK THAT COULD SUPPORT THE EPIGENETIC HYPOTHESIS, AND STUDIED ITS DYNAMICS WHICH HELPED TO DEFINE A DISCRIMINATING EXPERIMENTAL SCENARIO SUFFICIENT TO VALIDATE THE EPIGENETIC HYPOTHESIS. A MATHEMATICAL FRAMEWORK BASED ON FORMAL METHODS FROM COMPUTER SCIENCE ALLOWED A RIGOROUS VALIDATION AND CERTIFICATION OF PARAMETERS OF THIS MODEL LEADING TO EPIGENETIC BEHAVIOUR. THEN, WE DEMONSTRATED THAT A NON INDUCIBLE STRAIN OF P. AERUGINOSA CAN STABLY ACQUIRE THE CAPACITY TO BE INDUCED BY CALCIUM DEPLETION FOR THE TTSS AFTER A SHORT PULSE OF A REGULATORY PROTEIN. FINALLY, THE INCREASED CYTOTOXICITY OF A STRAIN AFTER THIS EPIGENETIC SWITCH WAS DEMONSTRATED IN VIVO IN AN ACUTE PULMONARY INFECTION MODEL. CONCLUSION: THESE RESULTS MAY OFFER NEW PERSPECTIVES FOR THERAPEUTIC STRATEGIES TO PREVENT LETHAL INFECTIONS BY P. AERUGINOSA BY REVERTING THE EPIGENETIC INDUCIBILITY OF TYPE III CYTOTOXICITY. 2006 2 1524 33 DNA METHYLATION CHANGES IN CYSTIC FIBROSIS: CAUSE OR CONSEQUENCE? TWIN AND SIBLING STUDIES HAVE SHOWN THAT LUNG DISEASE SEVERITY IS VARIABLE AMONG CYSTIC FIBROSIS (CF) PATIENTS AND AFFECTED TO THE SAME EXTENT BY GENETIC AND NONHERITABLE FACTORS. GENETIC FACTORS HAVE BEEN THOROUGHLY ASSESSED, WHEREAS THE MOLECULAR MECHANISMS WHEREBY NONHERITABLE FACTORS CONTRIBUTE TO THE PHENOTYPIC VARIABILITY OF CF PATIENTS ARE STILL UNKNOWN. EPIGENETIC MODIFICATIONS MAY REPRESENT THE MISSING LINK BETWEEN NONHERITABLE FACTORS AND PHENOTYPIC VARIATION IN CF. HEREIN, WE REVIEW RECENT STUDIES SHOWING THAT DNA METHYLATION IS ALTERED IN CF AND WE ADDRESS THREE POSSIBLE FACTORS RESPONSIBLE FOR THESE VARIATIONS: (I) OVERPRODUCTION OF REACTIVE OXYGEN SPECIES, (II) DEPLETION OF DNA METHYLATION COFACTORS AND (III) SUSCEPTIBILITY TO ACUTE AND CHRONIC BACTERIAL INFECTIONS. ALSO, WE HYPOTHESIZE THAT THE UNIQUE DNA METHYLATION PROFILE OF EACH PATIENT CAN MODULATE THE PHENOTYPE AND DISCUSS THE INTEREST OF IMPLEMENTING INTEGRATED GENOMIC, EPIGENOMIC AND TRANSCRIPTOMIC STUDIES TO FURTHER UNDERSTAND THE CLINICAL DIVERSITY OF CF PATIENTS (GRAPHICAL ABSTRACT). 2020 3 4028 41 LUNG TUMORS, COPD AND IMMUNE RESPONSE: IS EPIGENETICS THE BOTTOM LINE? NSCLC IS A HETEROGENEOUS DISORDER CONSISTING OF DISTINCT MOLECULAR SUBTYPES WHICH CAN BE TREATED BY USING SPECIFIC DRUGS TARGETED TO DISTINCT GENETIC LESIONS. IT IS WELL KNOWN THAT NSCLS INCIDENCE IS HIGHER IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS BECAUSE THEY SHARE A COMMON RISK FACTOR (CIGARETTE SMOKING) AND IT IS BELIEVED THAT THE TYPICAL INFLAMMATORY MICROENVIRONMENT OBSERVED IN COPD MAY INFLUENCE THE MOLECULAR MECHANISMS RESPONSIBLE OF CARCINOGENESIS. IN THE LAST YEARS, THE ROLE OF EPIGENETIC PROCESSES IN CELL BIOLOGY AND TISSUE PATHOLOGY HAS BEEN EXTENSIVELY STUDIED BOTH IN COPD AND NSCLC. THE RECENT PAPER BY WAUTERS ET AL. SHOWED A SPECIFIC PATTERN OF DRIVER MUTATIONS AND MOLECULAR FEATURES IN NSCLC RAISING IN THE CONTEXT OF COPD. ALL THESE FINDINGS HAVE SHOWN FOR THE FIRST TIME THAT LUNG TUMORS FOUND IN COPD PATIENTS DIFFER FROM THOSE OBSERVED IN PATIENT WITHOUT COPD DUE TO THE PRESENCE OF A SPECIFIC TUMOR MICROENVIRONMENT WHICH IS CHARACTERIZED BY REDUCED CD4+ TREG CELLS. ON THIS BASIS, THE PRESENT WORK AIMS AT DISCUSSING AND ANALYZING THE CONTEXT-SPECIFIC MECHANISMS OF CLONAL SELECTION AND EVOLUTION MAINLY FOCUSING ON THE EPIGENETIC ALTERATIONS AND AT POINTING OUT THE POTENTIAL THERAPEUTIC IMPLICATIONS. 2016 4 3418 33 HUMAN HEALTH CONSEQUENCES OF ENVIRONMENTALLY-MODULATED GENE EXPRESSION: POTENTIAL ROLES OF ELF-EMF INDUCED EPIGENETIC VERSUS MUTAGENIC MECHANISMS OF DISEASE. IN ORDER TO DETERMINE IF THERE MIGHT BE BIOLOGICAL AND HEALTH CONSEQUENCES AFTER EXPOSURES TO EXTREMELY-LOW FREQUENCY ELECTROMAGNETIC FIELDS (ELF-EMF), EITHER EXPERIMENTALLY OR EPIDEMIOLOGICALLY, MECHANISTIC UNDERSTANDING OF THE POTENTIAL MEANS BY WHICH ANY ENVIRONMENTAL AGENT CAN AFFECT CELLS IN A MULTICELLULAR ORGANISM HAS TO BE REVIEWED. THE GOAL OF THIS LIMITED REVIEW IS TO DEMONSTRATE THAT, WHILE THE PREVAILING PARADIGM OF THE ENVIRONMENTALLY-INDUCED ACUTE AND CHRONIC DISEASES INVOLVES EITHER CELL KILLING (CYTOTOXICITY) OR GENE/CHROMOSOME MUTATIONS (GENOTOXICITY), ALTERATION OF THE EXPRESSION OF GENETIC INFORMATION AT THE TRANSCRIPTIONAL (TURNING GENES "ON" OR "OFF"), TRANSLATIONAL (STABILIZING OR DE-STABILIZING THE GENETIC MESSAGE), OR POSTTRANSLATIONAL (ALTERING THE GENE PRODUCT OR PROTEIN) LEVELS HAS THE POTENTIAL TO CONTRIBUTE TO VARIOUS DISEASES. THIS LATTER MECHANISM, "EPIGENETIC" TOXICITY, UNLIKE THE FORMER TWO WHICH ARE IRREVERSIBLE, IS CHARACTERIZED BY THRESHOLD-LIKE ACTION, MULTIPLE BIOCHEMICAL PATHWAYS AND CHRONIC, REGULAR EXPOSURES TO BE EFFECTIVE. ULTIMATELY, EPIGENETIC TOXICANTS AFFECT ONE OF FOUR POTENTIAL CELL STATES, NAMELY ALTERATION OF CELL PROLIFERATION, CELL DIFFERENTIATION, PROGRAMMED CELL DEATH (APOPTOSIS) OR ADAPTIVE RESPONSES OF DIFFERENTIATED CELLS. 2000 5 2022 36 EPIGENETIC CHANGES ASSOCIATED WITH DISEASE PROGRESSION IN A MOUSE MODEL OF CHILDHOOD ALLERGIC ASTHMA. DEVELOPMENT OF ASTHMA IN CHILDHOOD IS LINKED TO VIRAL INFECTIONS OF THE LOWER RESPIRATORY TRACT IN EARLY LIFE, WITH SUBSEQUENT CHRONIC EXPOSURE TO ALLERGENS. PROGRESSION TO PERSISTENT ASTHMA IS ASSOCIATED WITH A TH2-BIASED IMMUNOLOGICAL RESPONSE AND STRUCTURAL REMODELLING OF THE AIRWAYS. THE UNDERLYING MECHANISMS ARE UNCLEAR, BUT COULD INVOLVE EPIGENETIC CHANGES. TO INVESTIGATE THIS, WE EMPLOYED A RECENTLY DEVELOPED MOUSE MODEL IN WHICH SELF-LIMITED NEONATAL INFECTION WITH A PNEUMOVIRUS, FOLLOWED BY SENSITISATION TO OVALBUMIN VIA THE RESPIRATORY TRACT AND LOW-LEVEL CHRONIC CHALLENGE WITH AEROSOLISED ANTIGEN, LEADS TO DEVELOPMENT OF AN ASTHMATIC PHENOTYPE. WE ASSESSED EXPRESSION OF MICRORNA BY CELLS IN THE PROXIMAL AIRWAYS, COMPARING CHANGES OVER THE PERIOD OF DISEASE PROGRESSION, AND USED TARGET PREDICTION DATABASES TO IDENTIFY GENES LIKELY TO BE UP- OR DOWNREGULATED AS A CONSEQUENCE OF ALTERED REGULATION OF MICRORNA. IN PARALLEL, WE ASSESSED DNA METHYLATION IN PULMONARY CD4(+) T CELLS. WE FOUND THAT A LIMITED NUMBER OF MICRORNAS EXHIBITED MARKED UP- OR DOWNREGULATION FOLLOWING EARLY-LIFE INFECTION AND SENSITISATION, FOR MANY OF WHICH THE LEVELS OF EXPRESSION WERE FURTHER CHANGED FOLLOWING CHRONIC CHALLENGE WITH THE SENSITIZING ANTIGEN. TARGETS OF THESE MICRORNAS INCLUDED GENES INVOLVED IN IMMUNE OR INFLAMMATORY RESPONSES (E.G. GATA3, KITL) AND IN TISSUE REMODELLING (E.G. IGF1, TGFBR1), AS WELL AS GENES FOR VARIOUS TRANSCRIPTION FACTORS AND SIGNALLING PROTEINS. IN PULMONARY CD4(+) T CELLS, THERE WAS SIGNIFICANT DEMETHYLATION AT PROMOTER SITES FOR INTERLEUKIN-4 AND INTERFERON-GAMMA, THE LATTER INCREASING FOLLOWING CHRONIC CHALLENGE. WE CONCLUDE THAT, IN THIS MODEL, PROGRESSION TO AN ASTHMATIC PHENOTYPE IS LINKED TO EPIGENETIC REGULATION OF GENES ASSOCIATED WITH INFLAMMATION AND STRUCTURAL REMODELLING, AND WITH T-CELL COMMITMENT TO A TH2 IMMUNOLOGICAL RESPONSE. EPIGENETIC CHANGES ASSOCIATED WITH THIS PATTERN OF GENE ACTIVATION MIGHT PLAY A ROLE IN THE DEVELOPMENT OF CHILDHOOD ASTHMA. 2013 6 761 36 CATEGORIZING THE CHARACTERISTICS OF HUMAN CARCINOGENS: A NEED FOR SPECIFICITY. THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER (IARC) HAS RECENTLY PROPOSED EMPLOYING "TEN KEY CHARACTERISTICS OF HUMAN CARCINOGENS" (TKCS) TO DETERMINE THE POTENTIAL OF AGENTS FOR HARMFUL EFFECTS. THE TKCS SEEM LIKELY TO CONFUSE THE UNSATISFACTORY CORRELATION FROM TESTING REGIMES THAT HAVE IGNORED THE DIFFERENCES EVIDENT WHEN CELLULAR CHANGES ARE COMPARED IN SHORT AND LONG-LIVED SPECIES, WITH THEIR VERY DIFFERENT STEM CELL AND SOMATIC CELL PHYLOGENIES. THE PROPOSED CHARACTERISTICS ARE SO BROAD THAT THEIR USE WILL LEAD TO AN INCREASE IN THE CURRENT UNACCEPTABLY HIGH RATE OF FALSE POSITIVES. IT COULD BE AN INFORMATIVE EXPERIMENT TO TAKE WELL-ESTABLISHED APPROVED THERAPEUTICS WITH WELL-KNOWN HUMAN SAFETY PROFILES AND TEST THEM AGAINST THIS NEW TKC PARADIGM. CANCERS ARE INITIATED AND DRIVEN BY HERITABLE AND TRANSIENT CHANGES IN GENE EXPRESSION, EXPAND CLONALLY, AND PROGRESS VIA ADDITIONAL ASSOCIATED ACQUIRED MUTATIONS AND EPIGENETIC ALTERATIONS THAT PROVIDE CELLS WITH AN EVOLUTIONARY ADVANTAGE. THE GENOTOXICITY TESTING PROTOCOLS CURRENTLY EMPLOYED AND REQUIRED BY REGULATION, EMPHASIZE TESTING FOR THE MUTATIONAL POTENTIAL OF THE TEST AGENT. TWO-YEAR, CHRONIC RODENT CANCER BIOASSAYS ARE INTENDED TO TEST FOR THE ENTIRE SPECTRUM OF CARCINOGENIC TRANSFORMATION. THE USE OF CYTOTOXIC DOSES CAUSING INCREASED, SUSTAINED CELL PROLIFERATION THAT FACILITATES ACCUMULATED GENETIC DAMAGE LEADS TO A HIGH FALSE-POSITIVE RATE OF TUMOR INDUCTION. CURRENT CANCER HAZARD ASSESSMENT PROTOCOLS AND WEIGHT-OF-THE-EVIDENCE ANALYSIS OF AGENT-SPECIFIC CANCER RISK ALIGN POORLY WITH THE PATHOGENESIS OF HUMAN CARCINOMA AND SO NEED MODERNIZATION AND IMPROVEMENT IN WAYS SUGGESTED HERE. 2021 7 2914 51 GENE REGULATORY NETWORK UNDERLYING THE IMMORTALIZATION OF EPITHELIAL CELLS. BACKGROUND: TUMORIGENIC TRANSFORMATION OF HUMAN EPITHELIAL CELLS IN VITRO HAS BEEN DESCRIBED EXPERIMENTALLY AS THE POTENTIAL RESULT OF SPONTANEOUS IMMORTALIZATION. THIS PROCESS IS CHARACTERIZED BY A SERIES OF CELL-STATE TRANSITIONS, IN WHICH NORMAL EPITHELIAL CELLS ACQUIRE FIRST A SENESCENT STATE WHICH IS LATER SURPASSED TO ATTAIN A MESENCHYMAL STEM-LIKE PHENOTYPE WITH A POTENTIALLY TUMORIGENIC BEHAVIOR. IN THIS PAPER WE AIM TO PROVIDE A SYSTEM-LEVEL MECHANISTIC EXPLANATION TO THE EMERGENCE OF THESE CELL TYPES, AND TO THE TIME-ORDERED TRANSITION PATTERNS THAT ARE COMMON TO NEOPLASIAS OF EPITHELIAL ORIGIN. TO THIS END, WE FIRST INTEGRATE PUBLISHED FUNCTIONAL AND WELL-CURATED MOLECULAR DATA OF THE COMPONENTS AND INTERACTIONS THAT HAVE BEEN FOUND TO BE INVOLVED IN SUCH CELL STATES AND TRANSITIONS INTO A NETWORK OF 41 MOLECULAR COMPONENTS. WE THEN REDUCE THIS INITIAL NETWORK BY REMOVING SIMPLE MEDIATORS (I.E., LINEAR PATHWAYS), AND FORMALIZE THE RESULTING REGULATORY CORE INTO LOGICAL RULES THAT GOVERN THE DYNAMICS OF EACH OF THE NETWORK COMPONENTS AS A FUNCTION OF THE STATES OF ITS REGULATORS. RESULTS: COMPUTATIONAL DYNAMIC ANALYSIS SHOWS THAT OUR PROPOSED GENE REGULATORY NETWORK MODEL RECOVERS EXACTLY THREE ATTRACTORS, EACH OF THEM DEFINED BY A SPECIFIC GENE EXPRESSION PROFILE THAT CORRESPONDS TO THE EPITHELIAL, SENESCENT, AND MESENCHYMAL STEM-LIKE CELLULAR PHENOTYPES, RESPECTIVELY. WE SHOW THAT ALTHOUGH A MESENCHYMAL STEM-LIKE STATE CAN BE ATTAINED EVEN UNDER UNPERTURBED PHYSIOLOGICAL CONDITIONS, THE LIKELIHOOD OF CONVERGING TO THIS STATE IS INCREASED WHEN PRO-INFLAMMATORY CONDITIONS ARE SIMULATED, PROVIDING A SYSTEMS-LEVEL MECHANISTIC EXPLANATION FOR THE CARCINOGENIC ROLE OF CHRONIC INFLAMMATORY CONDITIONS OBSERVED IN THE CLINIC. WE ALSO FOUND THAT THE REGULATORY CORE YIELDS AN EPIGENETIC LANDSCAPE THAT RESTRICTS TEMPORAL PATTERNS OF PROGRESSION BETWEEN THE STEADY STATES, SUCH THAT RECOVERED PATTERNS RESEMBLE THE TIME-ORDERED TRANSITIONS OBSERVED DURING THE SPONTANEOUS IMMORTALIZATION OF EPITHELIAL CELLS, BOTH IN VIVO AND IN VITRO. CONCLUSION: OUR STUDY STRONGLY SUGGESTS THAT THE IN VITRO TUMORIGENIC TRANSFORMATION OF EPITHELIAL CELLS, WHICH STRONGLY CORRELATES WITH THE PATTERNS OBSERVED DURING THE PATHOLOGICAL PROGRESSION OF EPITHELIAL CARCINOGENESIS IN VIVO, EMERGES FROM UNDERLYING REGULATORY NETWORKS INVOLVED IN EPITHELIAL TRANS-DIFFERENTIATION DURING DEVELOPMENT. 2017 8 6199 44 THE IMPORTANCE OF EPIGENETICS IN THE DEVELOPMENT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. IT IS GENERALLY ACCEPTED THAT GENETIC PREDISPOSITION PLAYS A ROLE IN COPD DEVELOPMENT IN SUSCEPTIBLE INDIVIDUALS. THEREFORE, MANY CANDIDATE GENES THAT COULD BE LINKED TO THE DEVELOPMENT OF DISEASE HAVE BEEN EXAMINED IN COPD. HOWEVER, INCONSISTENT RESULTS IN DIFFERENT STUDY POPULATIONS OFTEN LIMIT THIS APPROACH, SUGGESTING THAT NOT ONLY GENETICS, BUT ALSO OTHER FACTORS, MAY BE CONTRIBUTED TO THE SUSCEPTIBILITY TO COPD. EPIGENETIC MECHANISMS CAN AFFECT THE TRANSCRIPTIONAL ACTIVITY OF SPECIFIC GENES, AT DIFFERENT POINTS IN TIME, AND IN DIFFERENT ORGANS. MOREOVER, THESE MECHANISMS CAN HAVE AN EFFECT ON PEOPLE'S HEALTH. RECENTLY, THERE IS EMERGING EVIDENCE SUPPORTING A ROLE OF EPIGENETICS FOR THE REGULATION OF INFLAMMATORY GENES IN DISEASES SUCH AS ASTHMA AND COPD. MOREOVER, RECENT STUDIES SUGGEST THAT THE CURRENTLY USED TREATMENTS INCLUDING CORTICOSTEROIDS MAY WORK THROUGH EPIGENETIC MECHANISMS. EPIGENETIC REGULATION CAN BE REPROGRAMMED, POTENTIALLY AFFECTING THE RISK, AETIOLOGY AND TREATMENT OF VARIOUS DISEASE STATES. THE EPIGENETICALLY INFLUENCED PHENOTYPE COULD BE REVERSED WITH DEMETHYLATING OR DEACETYLATING AGENTS, CONSISTENT WITH EPIGENETIC PLASTICITY. THE POSTNATAL REVERSIBILITY OF THESE METHYLATION OR ACETYLATION EVENTS MAY THEREFORE PROVIDE GOOD OPPORTUNITIES FOR INTERVENTION. THE RECOGNITION OF THE ROLE OF GENETIC AND EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF COPD MAY IDENTIFY NOVEL TARGETS THAT HATCH NEW THERAPIES FOR PATIENTS WITH COPD. 2011 9 5894 34 T CELL EPIGENETIC REMODELING AND ACCELERATED EPIGENETIC AGING ARE LINKED TO LONG-TERM IMMUNE ALTERATIONS IN CHILDHOOD CANCER SURVIVORS. BACKGROUND: CANCER TREATMENTS HAVE SUBSTANTIALLY IMPROVED CHILDHOOD CANCER SURVIVAL BUT ARE ACCOMPANIED BY LONG-TERM COMPLICATIONS, NOTABLY CHRONIC INFLAMMATORY DISEASES. WE HYPOTHESIZE THAT CANCER TREATMENTS COULD LEAD TO LONG-TERM EPIGENETIC CHANGES IN IMMUNE CELLS, RESULTING IN INCREASED PREVALENCE OF INFLAMMATORY DISEASES IN CANCER SURVIVORS. RESULTS: TO TEST THIS HYPOTHESIS, WE ESTABLISHED THE EPIGENETIC AND TRANSCRIPTOMIC PROFILES OF IMMUNE CELLS FROM 44 CHILDHOOD CANCER SURVIVORS (CCS, > 16 YEARS OLD) ON FULL REMISSION (> 5 YEARS) WHO HAD RECEIVED CHEMOTHERAPY ALONE OR IN COMBINATION WITH TOTAL BODY IRRADIATION (TBI) AND HEMATOPOIETIC STEM CELL TRANSPLANT (HSCT). WE FOUND THAT MORE THAN 10 YEARS POST-TREATMENT, CCS TREATED WITH TBI/HSCT SHOWED AN ALTERED DNA METHYLATION SIGNATURE IN T CELL, PARTICULARLY AT GENES CONTROLLING IMMUNE AND INFLAMMATORY PROCESSES AND OXIDATIVE STRESS. DNA METHYLATION REMODELING IN T CELL WAS PARTIALLY ASSOCIATED WITH CHRONIC EXPRESSION CHANGES OF NEARBY GENES, INCREASED FREQUENCY OF TYPE 1 CYTOKINE-PRODUCING T CELL, ELEVATED SYSTEMIC LEVELS OF THESE CYTOKINES, AND OVER-ACTIVATION OF RELATED SIGNALING PATHWAYS. SURVIVORS EXPOSED TO TBI/HSCT WERE FURTHER CHARACTERIZED BY AN EPIGENETIC-AGING-SIGNATURE OF T CELL CONSISTENT WITH ACCELERATED EPIGENETIC AGING. TO INVESTIGATE THE POTENTIAL CONTRIBUTION OF IRRADIATION TO THESE CHANGES, WE ESTABLISHED TWO CELL CULTURE MODELS. WE IDENTIFIED THAT RADIATION PARTIALLY RECAPITULATED THE IMMUNE CHANGES OBSERVED IN SURVIVORS THROUGH A BYSTANDER EFFECT THAT COULD BE MEDIATED BY CIRCULATING FACTORS. CONCLUSION: CANCER TREATMENTS, IN PARTICULAR TBI/HSCT, ARE ASSOCIATED WITH LONG-TERM IMMUNE DISTURBANCES. WE PROPOSE THAT EPIGENETIC REMODELING OF IMMUNE CELLS FOLLOWING CANCER THERAPY AUGMENTS INFLAMMATORY- AND AGE-RELATED DISEASES, INCLUDING METABOLIC COMPLICATIONS, IN CHILDHOOD CANCER SURVIVORS. 2018 10 5130 30 POSTTRANSCRIPTIONAL GENE REGULATION: NOVEL PATHWAYS FOR GLUCOCORTICOIDS' ANTI-INFLAMMATORY ACTION. POSTTRANSCRIPTIONAL GENE REGULATION (PTR) IS A FUNDAMENTAL BIOLOGICAL PROCESS THAT INTEGRATES WITH THE MASTER TRANSCRIPTIONAL CONTROL OF GENE EXPRESSION, IN WAYS THAT ONLY IN THE LAST DECADE HAVE BEEN INCREASINGLY UNDERSTOOD [1, 2]. WHILE EPIGENETIC AND TRANSCRIPTIONAL EVENTS SHAPE CELL RESPONSE QUALITATIVELY, DECIDING THE PATTERN OF GENE EXPRESSION TO 'SWITCH ON OR OFF' IN RESPONSE TO ENDOGENOUS OR ENVIRONMENTAL TRIGGERS, THE KEY TASK OF PTR IS TO ACT AS A 'RHEOSTAT' AND RAPIDLY ADAPT THE CELLULAR RESPONSE BY PROVIDING THE APPROPRIATE AMPLITUDE AND TIMING TO THE PROTEIN EXPRESSION PATTERNS [3, 4]. THE PIVOTAL ROLE OF THIS MECHANISM COMES TO THE FOREFRONT IN INFLAMMATORY AND IMMUNE RESPONSE, WHERE THE CHANGES IN AMPLITUDE AND DURATION IN THE EXPRESSION OF DANGEROUS AND PROTECTIVE GENES ARE IN DELICATE BALANCE, AND ARE CRITICAL IN DETERMINING EITHER THE SUCCESSFUL RESOLUTION OF THE IMMUNE RESPONSE OR ITS CHRONIC OVEREXPRESSION [5]. THIS BRIEF REVIEW INTRODUCES MEMBERS OF THE MAIN CLASSES OF MOLECULES MEDIATING THE CYTOPLASMIC ARM OF GENE REGULATION, NAMELY RNA-BINDING PROTEINS AND MICRO-RNA (MIRNA), AND SUMMARIZES EXPERIMENTAL DATA THAT UNDERSCORE THE ROLE OF THESE MOLECULES IN THE PATHOPHYSIOLOGY OF CHRONIC INFLAMMATION, AS WELL AS THEIR PROMISING VALUE AS MECHANISMS CONVEYING THE ANTI-INFLAMMATORY EFFECT OF SYNTHETIC GLUCOCORTICOIDS. 2012 11 5281 36 PROMOTION AND SELECTION BY SERUM GROWTH FACTORS DRIVE FIELD CANCERIZATION, WHICH IS ANTICIPATED IN VIVO BY TYPE 2 DIABETES AND OBESITY. INDIVIDUALS SUFFERING FROM TYPE 2 DIABETES OR OBESITY EXHIBIT A SIGNIFICANT INCREASE IN THE INCIDENCE OF VARIOUS TYPES OF CANCER. IT IS GENERALLY ACCEPTED THAT THOSE CONDITIONS ARISE FROM OVERNUTRITION AND A SEDENTARY LIFESTYLE, WHICH LEAD TO INSULIN RESISTANCE CHARACTERIZED BY OVERPRODUCTION OF INSULIN ACTING AS A GROWTH FACTOR. THERE IS A CONSENSUS BASED LARGELY ON EPIDEMIOLOGICAL DATA THAT CHRONIC OVERPRODUCTION OF INSULIN IS RESPONSIBLE FOR THE INCREASED INCIDENCE OF CANCER. A MODEL SYSTEM IN CULTURE OF NIH 3T3 CELLS INDUCES THE COLLECTIVE EFFECTS OF SERUM GROWTH FACTORS ON PROGRESSION THROUGH THE STAGES OF FIELD CANCERIZATION. IT SHOWS THAT THE DRIVING FORCE OF PROGRESSION IS PROMOTION OF CELL GROWTH UNDER SELECTION AT HIGH CELL DENSITY, WITH NO REQUIREMENT FOR EXOGENOUS CARCINOGENIC AGENTS. THE EARLY EFFECT IS GRADUAL SELECTION AMONG MANY PREEXISTING, LOW-PENETRANCE PRENEOPLASTIC MUTATIONS OR STABLE EPIGENETIC VARIANTS, FOLLOWED BY SPORADIC, HIGH-PENETRANCE TRANSFORMING VARIANTS, ALL DEPENDENT ON ENDOGENOUS PROCESSES. THE SIGNIFICANCE OF THE RESULTS FOR CANCER IN DIABETIC AND OBESE INDIVIDUALS IS THAT THE INITIAL STAGES OF THE PROCESS INVOLVE MULTIORGAN METABOLIC INTERACTIONS THAT PRODUCE A SYSTEMIC INSULIN RESISTANCE WITH CHRONIC OVERPRODUCTION OF INSULIN AND LOCALIZED FIELD CANCERIZATION. HYPOMAGNESEMIA IS PREVALENT IN THE FOREGOING METABALO/SYSTEMIC DISORDERS, AND MAY ALSO PROVIDE A SELECTIVE MICROENVIRONMENT FOR TUMOR DEVELOPMENT. 2013 12 5618 34 SARS-COV-2 INTERACTION WITH HUMAN DNA METHYL TRANSFERASE 1: A POTENTIAL RISK FOR INCREASING THE INCIDENCE OF LATER CHRONIC DISEASES IN THE SURVIVED PATIENTS. CURRENTLY, THE COVID-19 PANDEMIC IS THE MOST DISCUSSED SUBJECT IN MEDICAL RESEARCHES WORLDWIDE. AS THE KNOWLEDGE IS EXPANDED ABOUT THE DISEASE, MORE HYPOTHESES BECOME CREATED. A RECENT STUDY ON THE VIRAL PROTEIN INTERACTION MAP REVEALED THAT SARS-COV-2 OPEN READING FRAME 8 (ORF8) INTERACTS WITH HUMAN DNA METHYL TRANSFERASE1 (DNMT1), AN ACTIVE EPIGENETIC AGENT IN DNA METHYLATION. MOREOVER, DNMT1 IS A CONTRIBUTOR TO A VARIETY OF CHRONIC DISEASES WHICH COULD CAUSE SOME EPIGENETIC DYSREGULATION IN INFECTED CELLS, ESPECIALLY LEUKOCYTES, PANCREATIC BETA, AND ENDOTHELIAL CELLS. REGARDING THE FACT THAT EPIGENETIC ALTERATIONS HAVE A PARTIAL, BUT NOT COMPLETELY REVERSIBLE PHENOMENA, IT RAISES THE QUESTION THAT IF THIS INTERACTION MAY CAUSE LONG-TERM COMPLICATIONS SUCH AS DIABETES, ATHEROSCLEROSIS, CANCER, AND AUTOIMMUNE DISEASES. ACCORDINGLY, LONG FOLLOW-UP STUDIES ON THE RECOVERED PATIENTS FROM COVID-19 ARE RECOMMENDED. 2022 13 2059 33 EPIGENETIC CONTROL OF GENE EXPRESSION IN THE LUNG. EPIGENETICS IS TRADITIONALLY DEFINED AS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE. THERE ARE THREE MAIN CLASSES OF EPIGENETIC MARKS--DNA METHYLATION, MODIFICATIONS OF HISTONE TAILS, AND NONCODING RNAS--EACH OF WHICH MAY BE INFLUENCED BY THE ENVIRONMENT, DIET, DISEASES, AND AGEING. IMPORTANTLY, EPIGENETIC MARKS HAVE BEEN SHOWN TO INFLUENCE IMMUNE CELL MATURATION AND ARE ASSOCIATED WITH THE RISK OF DEVELOPING VARIOUS FORMS OF CANCER, INCLUDING LUNG CANCER. MOREOVER, THERE IS EMERGING EVIDENCE THAT THESE EPIGENETIC MARKS AFFECT GENE EXPRESSION IN THE LUNG AND ARE ASSOCIATED WITH BENIGN LUNG DISEASES, SUCH AS ASTHMA, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND INTERSTITIAL LUNG DISEASE. TECHNOLOGICAL ADVANCES HAVE MADE IT FEASIBLE TO STUDY EPIGENETIC MARKS IN THE LUNG, AND IT IS ANTICIPATED THAT THIS KNOWLEDGE WILL ENHANCE OUR UNDERSTANDING OF THE DYNAMIC BIOLOGY IN THE LUNG AND LEAD TO THE DEVELOPMENT OF NOVEL DIAGNOSTIC AND THERAPEUTIC APPROACHES FOR OUR PATIENTS WITH LUNG DISEASE. 2011 14 389 28 AN INTEGRATIVE HYPOTHESIS LINKING CANCER, DIABETES AND ATHEROSCLEROSIS: THE ROLE OF MUTATIONS AND EPIGENETIC CHANGES. IT APPEARS THAT THE DISEASE STATES OF CANCER, ALTHEROSCLEROSIS AND DIABETES MIGHT SHARE A COMMON ETIOLOGY. THESE CHRONIC DISEASES APPEAR TO BE MULTI-STAGED IN THEIR PROGRESSION, WITH GENETIC, NUTRITIONAL, PSYCHO-SOCIAL, ENVIRONMENTAL AND VIRAL FACTORS INFLUENCING THEIR APPEARANCE. WE OFFERED A HYPOTHESIS (A "MUTATION THEORY OF DISEASE"), STATING THAT THESE DISEASES CAN BE DESCRIBED BY INITIATION AND PROMOTION PHASES; INITIATION BEING THE RESULT OF THE PRODUCTION OF MUTATED CELLS AFTER UNREPAIRED DAMAGED DNA IS REPLICATED; PROMOTION BEING THE SELECTIVE PROLIFERATION OF THE INITIATED CELLS TO FORM CLONES OF MUTATED CELLS. IT WAS FURTHER POSTULATED THAT PROMOTION AFFECTS CELL PROLIFERATION BY ALTERING A MEMBRANE-CA++ REGULATORY SYSTEM. DEPENDING ON THE NATURE OF THE MUTATION IN THE CLONE OF CELLS, SPECIFIC DISEASE STATES WOULD RESULT. THE ROLES OF RADIATIONS, CHEMICALS, VIRUSES, GENES, NUTRITION AND PSYCHO-SOCIAL STRESS WERE RELATED TO EITHER THE INITIATION (MUTATION PRODUCTION) OR THE PROMOTION (CELL PROLIFERATION) PHASE OF THESE DISEASES. 1980 15 4027 34 LUNG CANCER IN A CF PATIENT: COMBINATION OF BAD LUCK OR IS THERE MORE TO SAY? PATIENTS WITH CYSTIC FIBROSIS HAVE INCREASED RISK FOR GASTROINTESTINAL CANCER, LYMPHOID LEUKEMIA AND TESTICULAR CARCINOMAS. CHRONIC INFLAMMATION DOES NOT SEEM TO BE THE ONLY CONTRIBUTING FACTOR. MUTATIONS AND EPIGENETIC ALTERATIONS IN THE CFTR GENE MAY ALTER SUSCEPTIBILITY TO DEVELOP CANCER. LUNG CANCER IS UP TO NOW NOT FREQUENTLY OBSERVED IN CF PATIENTS. IN LUNG CANCER PATIENTS WITHOUT CF LOW CFTR EXPRESSION IS SIGNIFICANTLY ASSOCIATED WITH ADVANCED STAGING, LYMPH NODE METASTASIS. AS THE MANAGEMENT AND LIFE EXPECTANCY OF PATIENTS WITH CYSTIC FIBROSIS HAVE IMPROVED SUBSTANTIALLY IN RECENT YEARS, WE EXPECT AN INCREASED NUMBER OF THESE PATIENTS DIAGNOSED WITH LUNG CANCER. IN ADDITION, IT IS POSSIBLE THAT THEY, AS A RESULT OF CFTR-DYSFUNCTION, WILL PRESENT WITH MORE AGGRESSIVE LUNG TUMORS. TREATING CANCER IN CF PATIENTS IS A CHALLENGE BECAUSE OF MULTI-ORGAN INVOLVEMENT AND CHRONIC COLONIZATION BY RESISTANT PATHOGENS. THE EFFECTIVENESS AND SAFETY OF IMMUNOTHERAPY IN THIS POPULATION NEEDS TO BE FURTHER EVALUATED. 2021 16 5134 37 POTENTIAL HEALTH RISKS OF MRNA-BASED VACCINE THERAPY: A HYPOTHESIS. THERAPEUTIC APPLICATIONS OF SYNTHETIC MRNA WERE PROPOSED MORE THAN 30 YEARS AGO, AND ARE CURRENTLY THE BASIS OF ONE OF THE VACCINE PLATFORMS USED AT A MASSIVE SCALE AS PART OF THE PUBLIC HEALTH STRATEGY TO GET COVID-19 UNDER CONTROL. TO DATE, THERE ARE NO PUBLISHED STUDIES ON THE BIODISTRIBUTION, CELLULAR UPTAKE, ENDOSOMAL ESCAPE, TRANSLATION RATES, FUNCTIONAL HALF-LIFE AND INACTIVATION KINETICS OF SYNTHETIC MRNA, RATES AND DURATION OF VACCINE-INDUCED ANTIGEN EXPRESSION IN DIFFERENT CELL TYPES. FURTHERMORE, DESPITE THE ASSUMPTION THAT THERE IS NO POSSIBILITY OF GENOMIC INTEGRATION OF THERAPEUTIC SYNTHETIC MRNA, ONLY ONE RECENT STUDY HAS EXAMINED INTERACTIONS BETWEEN VACCINE MRNA AND THE GENOME OF TRANSFECTED CELLS, AND REPORTED THAT AN ENDOGENOUS RETROTRANSPOSON, LINE-1 IS UNSILENCED FOLLOWING MRNA ENTRY TO THE CELL, LEADING TO REVERSE TRANSCRIPTION OF FULL LENGTH VACCINE MRNA SEQUENCES, AND NUCLEAR ENTRY. THIS FINDING SHOULD BE A MAJOR SAFETY CONCERN, GIVEN THE POSSIBILITY OF SYNTHETIC MRNA-DRIVEN EPIGENETIC AND GENOMIC MODIFICATIONS ARISING. WE PROPOSE THAT IN SUSCEPTIBLE INDIVIDUALS, CYTOSOLIC CLEARANCE OF NUCLEOTIDE MODIFIED SYNTHETIC (NMS-MRNAS) IS IMPEDED. SUSTAINED PRESENCE OF NMS-MRNA IN THE CYTOPLASM DEREGULATES AND ACTIVATES ENDOGENOUS TRANSPOSABLE ELEMENTS (TES), CAUSING SOME OF THE MRNA COPIES TO BE REVERSE TRANSCRIBED. THE CYTOSOLIC ACCUMULATION OF THE NMS-MRNA AND THE REVERSE TRANSCRIBED CDNA MOLECULES ACTIVATES RNA AND DNA SENSORY PATHWAYS. THEIR CONCURRENT ACTIVATION INITIATES A SYNCHRONIZED INNATE RESPONSE AGAINST NON-SELF NUCLEIC ACIDS, PROMPTING TYPE-I INTERFERON AND PRO-INFLAMMATORY CYTOKINE PRODUCTION WHICH, IF UNREGULATED, LEADS TO AUTOINFLAMMATORY AND AUTOIMMUNE CONDITIONS, WHILE ACTIVATED TES INCREASE THE RISK OF INSERTIONAL MUTAGENESIS OF THE REVERSE TRANSCRIBED MOLECULES, WHICH CAN DISRUPT CODING REGIONS, ENHANCE THE RISK OF MUTATIONS IN TUMOUR SUPPRESSOR GENES, AND LEAD TO SUSTAINED DNA DAMAGE. SUSCEPTIBLE INDIVIDUALS WOULD THEN EXPECTEDLY HAVE AN INCREASED RISK OF DNA DAMAGE, CHRONIC AUTOINFLAMMATION, AUTOIMMUNITY AND CANCER. IN LIGHT OF THE CURRENT MASS ADMINISTRATION OF NMS-MRNA VACCINES, IT IS ESSENTIAL AND URGENT TO FULLY UNDERSTAND THE INTRACELLULAR CASCADES INITIATED BY CELLULAR UPTAKE OF SYNTHETIC MRNA AND THE CONSEQUENCES OF THESE MOLECULAR EVENTS. 2023 17 45 35 A COMPREHENSIVE REVIEW ON RNA INTERFERENCE-MEDIATED TARGETING OF INTERLEUKINS AND ITS POTENTIAL THERAPEUTIC IMPLICATIONS IN COLON CANCER. COLON CANCER IS THE WORLD'S FOURTH LEADING CAUSE OF DEATH. IT IS CANCER OF THE LATTER PART OF THE LARGE INTESTINE, I.E. THE COLON. CHRONIC INFLAMMATION OVER A LONG PERIOD ALSO LEADS TO THE DEVELOPMENT OF CANCER. CANCER IN THE COLON REGION IS ARDUOUS TO DIAGNOSE AND IS DETECTED AT A LATER STAGE WHEN IT METASTASIZES TO OTHER PARTS OF THE BODY LIKE THE LIVER, LUNGS, PERITONEUM, ETC. COLON CANCER IS A GREAT EXAMPLE OF SOLID TUMOURS ASSOCIATED WITH CHRONIC INFLAMMATION. ALTHOUGH CONVENTIONAL THERAPIES ARE EFFECTIVE, THEY LOSE THEIR EFFECTIVENESS BEYOND A CERTAIN POINT. RELAPSE OF THE DISEASE OCCURS FREQUENTLY. RNA INTERFERENCE (RNAI) IS EMERGING AS A GREAT TOOL TO SPECIFICALLY ATTACK THE CANCER CELLS OF A TARGET SITE LIKE THE COLON. RNAI DEALS WITH EPIGENETIC CHANGES MADE IN THE DEFECTIVE CELLS WHICH ULTIMATELY LEADS TO THEIR DEATH WITHOUT HARMING THE HEALTHY CELLS. IN THIS REVIEW, TWO TYPES OF EPIGENETIC MODULATORS HAVE BEEN CONSIDERED, NAMELY SIRNA AND MIRNA, AND THEIR EFFECT ON INTERLEUKINS. INTERLEUKINS, A CLASS OF CYTOKINES, ARE MAJOR INFLAMMATORY RESPONSES OF THE BODY THAT ARE RELEASED BY IMMUNE CELLS LIKE LEUKOCYTES AND MACROPHAGES. SOME OF THESE INTERLEUKINS ARE PRO-INFLAMMATORY, THEREBY PROMOTING INFLAMMATION WHICH EVENTUALLY CAUSES CANCER. RNAI CAN PREVENT COLON CANCER BY INHIBITING PRO-INFLAMMATORY INTERLEUKINS. 2023 18 4 34 "MIX OF MICS"- PHENOTYPIC AND BIOLOGICAL HETEROGENEITY OF "MULTIPOTENT" MUSCLE INTERSTITIAL CELLS (MICS). THE CAPACITY OF ADULT SKELETAL MUSCLE FOR REGENERATION APPEARS TO BE LIMITED, WITH PROGRESSIVE IMPAIRMENT IN REPAIR EFFICIENCY OF INJURED MUSCLES OBSERVED IN CHRONIC MUSCULAR DISORDERS AND DURING AGING. WHILE SATELLITE CELLS, THE COMMITTED ADULT MUSCLE STEM CELLS, ARE THE MAIN DIRECT CELL SOURCE SUPPORTING THE REGENERATIVE POTENTIAL OF ADULT SKELETAL MUSCLES, THE CHARACTERIZATION OF THE CELL TYPES AND SIGNALS THAT CONSTITUTE THE FUNCTIONAL "NICHE" OF SATELLITE CELLS IS CURRENTLY THE OBJECT OF INTENSE INVESTIGATION. RECENT STUDIES HAVE IDENTIFIED A FUNCTIONAL RELATIONSHIP BETWEEN SATELLITE CELLS AND VARIOUS CELL TYPES LOCATED IN KEY ANATOMICAL POSITION, SUCH AS THE INTERSTITIUM OF SKELETAL MUSCLES. THIS HETEROGENEOUS POPULATION OF MUSCLE INTERSTITIAL CELLS (MICS) APPEARS TO RETAIN AN INTRINSIC MULTIPOTENCY WITHIN THE MESODERMAL LINEAGE, AND THEIR DIRECT OR INDIRECT CONTRIBUTION TO MYOFIBER TURNOVER, REPAIR AND DEGENERATION HAS BEEN SUGGESTED BY MANY STUDIES THAT WILL BE REVIEWED HERE. GIVEN THE EXISTING GAP OF KNOWLEDGE ON LINEAGE IDENTITY AND FUNCTIONAL PROPERTIES OF MICS, THEIR DETAILED CHARACTERIZATION AT THE SINGLE CELL LEVEL HOLDS THE PROMISE TO PROVIDE KEY INSIGHT INTO THE COMPOSITION OF THIS HETEROGENEOUS POPULATION AND THE DYNAMIC TRANSITION THROUGH DISTINCT SUB-POPULATIONS IN HEALTHY, DISEASED AND AGING MUSCLES. THIS REVIEW PROVIDES AN OVERVIEW OF THE RESULTS OF VARIOUS STUDIES DESCRIBING THE PHENOTYPE AND THE FUNCTION OF CELLS ISOLATED FROM SKELETAL MUSCLE INTERSTITIUM, AND DISCUSSES THE IMPORTANCE OF SINGLE CELL TRANSCRIPTION PROFILING IN ORDER TO DECIPHER THE FUNCTIONAL AND PHENOTYPICAL HETEROGENEITY OF MUSCLE INTERSTITIAL CELLS (MICS). 2012 19 1326 26 DEPLETION OF NUCLEAR HISTONE H2A VARIANTS IS ASSOCIATED WITH CHRONIC DNA DAMAGE SIGNALING UPON DRUG-EVOKED SENESCENCE OF HUMAN SOMATIC CELLS. CELLULAR SENESCENCE IS ASSOCIATED WITH GLOBAL CHROMATIN CHANGES, ALTERED GENE EXPRESSION, AND ACTIVATION OF CHRONIC DNA DAMAGE SIGNALING. THESE EVENTS ULTIMATELY LEAD TO MORPHOLOGICAL AND PHYSIOLOGICAL TRANSFORMATIONS IN PRIMARY CELLS. IN THIS STUDY, WE SHOW THAT CHRONIC DNA DAMAGE SIGNALS CAUSED BY GENOTOXIC STRESS IMPACT THE EXPRESSION OF HISTONES H2A FAMILY MEMBERS AND LEAD TO THEIR DEPLETION IN THE NUCLEI OF SENESCENT HUMAN FIBROBLASTS. OUR DATA REINFORCE THE HYPOTHESIS THAT PROGRESSIVE CHROMATIN DESTABILIZATION MAY LEAD TO THE LOSS OF EPIGENETIC INFORMATION AND IMPAIRED CELLULAR FUNCTION ASSOCIATED WITH CHRONIC DNA DAMAGE UPON DRUG-EVOKED SENESCENCE. WE PROPOSE THAT CHANGES IN THE HISTONE BIOSYNTHESIS AND CHROMATIN ASSEMBLY MAY DIRECTLY CONTRIBUTE TO CELLULAR AGING. IN ADDITION, WE ALSO OUTLINE THE METHOD THAT ALLOWS FOR QUANTITATIVE AND UNBIASED MEASUREMENT OF THESE CHANGES. 2012 20 6136 42 THE EPIGENETICS OF MULTIPLE SCLEROSIS AND OTHER RELATED DISORDERS. MULTIPLE SCLEROSIS (MS) IS A DEMYELINATING DISEASE CHARACTERIZED BY CHRONIC INFLAMMATION OF THE CENTRAL NERVOUS SYSTEM (CNS) GRAY AND WHITE MATTER. ALTHOUGH THE CAUSE OF MS IS UNKNOWN, IT IS WIDELY APPRECIATED THAT INNATE AND ADAPTIVE IMMUNE PROCESSES CONTRIBUTE TO ITS PATHOGENESIS. THESE INCLUDE MICROGLIA/MACROPHAGE ACTIVATION, PRO-INFLAMMATORY T-CELL (TH1) RESPONSES AND HUMORAL RESPONSES. ADDITIONALLY, THERE IS EVIDENCE INDICATING THAT MS HAS A NEURODEGENERATIVE COMPONENT SINCE NEURONAL AND AXONAL LOSS OCCURS EVEN IN THE ABSENCE OF OVERT INFLAMMATION. THESE ASPECTS ALSO FORM THE RATIONALE FOR CLINICAL MANAGEMENT OF THE DISEASE. HOWEVER, THE CURRENTLY AVAILABLE THERAPIES TO CONTROL THE DISEASE ARE ONLY PARTIALLY EFFECTIVE AT BEST INDICATING THAT MORE EFFECTIVE THERAPEUTIC SOLUTIONS ARE URGENTLY NEEDED. IT IS APPRECIATED THAT IN THE IMMUNE-DRIVEN AND NEURODEGENERATIVE PROCESSES MS-SPECIFIC DEREGULATION OF GENE EXPRESSIONS AND RESULTING PROTEIN DYSFUNCTION ARE THOUGHT TO PLAY A CENTRAL ROLE. THESE DEVIATIONS IN GENE EXPRESSION PATTERNS CONTRIBUTE TO THE INFLAMMATORY RESPONSE IN THE CNS, AND TO NEURONAL OR AXONAL LOSS. EPIGENETIC MECHANISMS CONTROL TRANSCRIPTION OF MOST, IF NOT ALL GENES, IN NUCLEATED CELLS INCLUDING CELLS OF THE CNS AND IN HAEMATOPOIETIC CELLS. MS-SPECIFIC ALTERATIONS IN EPIGENETIC REGULATION OF GENE EXPRESSION MAY THEREFORE LIE AT THE HEART OF THE DEREGULATION OF GENE EXPRESSION IN MS. AS SUCH, EPIGENETIC MECHANISMS MOST LIKELY PLAY AN IMPORTANT ROLE IN DISEASE PATHOGENESIS. IN THIS REVIEW WE DISCUSS A ROLE FOR MS-SPECIFIC DEREGULATION OF EPIGENETIC FEATURES THAT CONTROL GENE EXPRESSION IN THE CNS AND IN THE PERIPHERY. FURTHERMORE, WE DISCUSS THE APPLICATION OF SMALL MOLECULE INHIBITORS THAT TARGET THE EPIGENETIC MACHINERY TO AMELIORATE DISEASE IN EXPERIMENTAL ANIMAL MODELS, INDICATING THAT SUCH APPROACHES MAY BE APPLICABLE TO MS PATIENTS. 2014