1 4018 173 LOW-DOSE IONIZING RADIATION: INDUCTION OF DIFFERENTIAL INTRACELLULAR SIGNALLING POSSIBLY AFFECTING INTERCELLULAR COMMUNICATION. GIVEN THE COMPLEXITY OF THE CARCINOGENIC PROCESS AND THE LACK OF ANY MECHANISTIC UNDERSTANDING OF HOW IONIZING RADIATION AT LOW-LEVEL EXPOSURES AFFECTS THE MULTISTAGE, MULTIMECHANISM PROCESSES OF CARCINOGENESIS, IT IS IMPERATIVE THAT CONCEPTS AND PARADIGMS BE REEXAMINED WHEN EXTRAPOLATING FROM HIGH DOSE TO LOW DOSE. ANY HEALTH EFFECT DIRECTLY LINKED TO LOW-DOSE RADIATION EXPOSURE MUST HAVE MOLECULAR/BIOCHEMICAL AND BIOLOGICAL BASES. ON THE OTHER HAND, DEMONSTRATING SOME MOLECULAR/BIOCHEMICAL OR CELLULAR EFFECT, USING SURROGATE SYSTEMS FOR THE HUMAN BEING, DOES NOT NECESSARILY IMPLY A CORRESPONDING HEALTH EFFECT. GIVEN THE GENERAL ACCEPTANCE OF AN EXTRAPOLATED LNT MODEL, OUR CURRENT UNDERSTANDING OF CARCINOGENESIS CRIES OUT FOR A RESOLUTION OF A REAL PROBLEM. HOW CAN A LOW-LEVEL ACUTE, OR EVEN A CHRONIC, EXPOSURE OF IONIZING RADIATION BRING ABOUT ALL THE DIFFERENT MECHANISMS (MUTAGENIC, CYTOTOXIC, AND EPIGENETIC) AND GENOTYPIC/PHENOTYPIC CHANGES NEEDED TO CONVERT NORMAL CELLS TO AN INVASIVE, MALIGNANT CELL, GIVEN ALL THE PROTECTIVE, REPAIR, AND SUPPRESSIVE SYSTEMS KNOWN TO EXIST IN THE HUMAN BODY? UNTIL RECENTLY, THE PREVAILING PARADIGM THAT IONIZING RADIATION BRINGS ABOUT CANCER PRIMARILY BY DNA DAMAGE AND ITS CONVERSION TO GENE AND CHROMOSOMAL MUTATIONS, DROVE OUR INTERPRETATION OF RADIATION CARCINOGENESIS. TODAY, OUR KNOWLEDGE INCLUDES THE FACTS BOTH THAT EPIGENETIC EVENTS PLAY A MAJOR ROLE IN CARCINOGENESIS AND THAT LOW-DOSE RADIATION CAN ALSO INDUCE EPIGENETIC EVENTS IN AND BETWEEN CELLS IN TISSUES. THIS CHALLENGES ANY SIMPLE EXTRAPOLATION OF THE LNT MODEL. ALTHOUGH A RECENT DELINEATION OF "HALLMARKS" OF THE CANCER PROCESS HAS HELPED TO FOCUS ON HOW IONIZING RADIATION MIGHT CONTRIBUTE TO THE INDUCTION OF CANCERS, SEVERAL OTHER HALLMARKS, PREVIOUSLY IGNORED--NAMELY, THE STEM CELLS IN TISSUES AS TARGETS FOR CARCINOGENESIS AND THE ROLE OF CELL-CELL COMMUNICATION PROCESSES IN MODULATING THE RADIATION EFFECTS ON THE TARGET CELL--MUST BE CONSIDERED, PARTICULARLY FOR THE ADAPTIVE RESPONSE, BYSTANDER EFFECTS, AND GENOMIC INSTABILITY PHENOMENA. 2005 2 6733 39 WHAT CAN CHEMICAL CARCINOGENESIS SHED LIGHT ON THE LNT HYPOTHESIS IN RADIATION CARCINOGENESIS? TO PROTECT THE PUBLIC'S HEALTH FROM EXPOSURE TO PHYSICAL, CHEMICAL, AND MICROBIOLOGICAL AGENTS, IT IS IMPORTANT THAT ANY POLICY BE BASED ON RIGOROUS SCIENTIFICALLY BASED RESEARCH. THE CONCEPT OF "LINEAR NO-THRESHOLD" (LNT) HAS BEEN IMPLEMENTED TO PROVIDE GUIDELINE EXPOSURES TO THESE AGENTS. THE PRACTICAL LIMITATION TO TESTING THIS HYPOTHESIS IS TO PROVIDE SUFFICIENT SAMPLES FOR EXPERIMENTAL OR EPIDEMIOLOGICAL STUDIES. WHILE THERE IS NO UNIVERSALLY ACCEPTED UNDERSTANDING OF MOST HUMAN DISEASES, THERE SEEMS TO BE BETTER UNDERSTANDING OF CANCER THAT MIGHT HELP RESOLVE THE "LNT" MODEL. THE PUBLIC'S CONCERN, AFTER BEING EXPOSED TO RADIATION, IS THE POTENTIAL OF PRODUCING CANCER. THE MOST RIGOROUS HYPOTHESIS OF HUMAN CARCINOGENESIS IS THE "MULTISTAGE, MULTIMECHANISM" CHEMICAL CARCINOGENESIS MODEL. THE RADIATION CARCINOGENESIS LNT MODEL, RARELY, IF EVER, BUILT IT INTO THEIR SUPPORT. IT WILL BE ARGUED THAT THIS MULTISTAGE, MULTIMECHANISM MODEL OF CARCINOGENESIS, INVOLVING THE "INITIATION" OF A SINGLE CELL BY A MUTAGEN EVENT, FOLLOWED BY CHRONIC EXPOSURE TO THRESHOLD LEVELS OF EPIGENETIC AGENTS OR CONDITIONS THAT STIMULATE THE CLONAL EXPANSION OF THE "INITIATED" CELL, CAN CONVERT THESE BENIGN CELLS TO BECOME INVASIVE AND METASTATIC. THIS "PROMOTION" PROCESS CAN BE INTERRUPTED, THEREBY PREVENTING THESE INITIATED CELLS FROM TRANSITIONING TO THE "PROGRESSION" PROCESS OF INVASION AND METASTASIS. 2019 3 266 57 ADVERSE OUTCOME PATHWAYS FOR IONIZING RADIATION AND BREAST CANCER INVOLVE DIRECT AND INDIRECT DNA DAMAGE, OXIDATIVE STRESS, INFLAMMATION, GENOMIC INSTABILITY, AND INTERACTION WITH HORMONAL REGULATION OF THE BREAST. KNOWLEDGE ABOUT ESTABLISHED BREAST CARCINOGENS CAN SUPPORT IMPROVED AND MODERNIZED TOXICOLOGICAL TESTING METHODS BY IDENTIFYING KEY MECHANISTIC EVENTS. IONIZING RADIATION (IR) INCREASES THE RISK OF BREAST CANCER, ESPECIALLY FOR WOMEN AND FOR EXPOSURE AT YOUNGER AGES, AND EVIDENCE OVERALL SUPPORTS A LINEAR DOSE-RESPONSE RELATIONSHIP. WE USED THE ADVERSE OUTCOME PATHWAY (AOP) FRAMEWORK TO OUTLINE AND EVALUATE THE EVIDENCE LINKING IONIZING RADIATION WITH BREAST CANCER FROM MOLECULAR INITIATING EVENTS TO THE ADVERSE OUTCOME THROUGH INTERMEDIATE KEY EVENTS, CREATING A QUALITATIVE AOP. WE IDENTIFIED KEY EVENTS BASED ON REVIEW ARTICLES, SEARCHED PUBMED FOR RECENT LITERATURE ON KEY EVENTS AND IR, AND IDENTIFIED ADDITIONAL PAPERS USING REFERENCES. WE MANUALLY CURATED PUBLICATIONS AND EVALUATED DATA QUALITY. IONIZING RADIATION DIRECTLY AND INDIRECTLY CAUSES DNA DAMAGE AND INCREASES PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES (RONS). RONS LEAD TO DNA DAMAGE AND EPIGENETIC CHANGES LEADING TO MUTATIONS AND GENOMIC INSTABILITY (GI). PROLIFERATION AMPLIFIES THE EFFECTS OF DNA DAMAGE AND MUTATIONS LEADING TO THE AO OF BREAST CANCER. SEPARATELY, RONS AND DNA DAMAGE ALSO INCREASE INFLAMMATION. INFLAMMATION CONTRIBUTES TO DIRECT AND INDIRECT EFFECTS (EFFECTS IN CELLS NOT DIRECTLY REACHED BY IR) VIA POSITIVE FEEDBACK TO RONS AND DNA DAMAGE, AND SEPARATELY INCREASES PROLIFERATION AND BREAST CANCER THROUGH PRO-CARCINOGENIC EFFECTS ON CELLS AND TISSUE. FOR EXAMPLE, GENE EXPRESSION CHANGES ALTER INFLAMMATORY MEDIATORS, RESULTING IN IMPROVED SURVIVAL AND GROWTH OF CANCER CELLS AND A MORE HOSPITABLE TISSUE ENVIRONMENT. ALL OF THESE EVENTS OVERLAP AT MULTIPLE POINTS WITH EVENTS CHARACTERISTIC OF "BACKGROUND" INDUCTION OF BREAST CARCINOGENESIS, INCLUDING HORMONE-RESPONSIVE PROLIFERATION, OXIDATIVE ACTIVITY, AND DNA DAMAGE. THESE OVERLAPS MAKE THE BREAST PARTICULARLY SUSCEPTIBLE TO IONIZING RADIATION AND REINFORCE THAT THESE BIOLOGICAL ACTIVITIES ARE IMPORTANT CHARACTERISTICS OF CARCINOGENS. AGENTS THAT INCREASE THESE BIOLOGICAL PROCESSES SHOULD BE CONSIDERED POTENTIAL BREAST CARCINOGENS, AND PREDICTIVE METHODS ARE NEEDED TO IDENTIFY CHEMICALS THAT INCREASE THESE PROCESSES. TECHNIQUES ARE AVAILABLE TO MEASURE RONS, DNA DAMAGE AND MUTATION, CELL PROLIFERATION, AND SOME INFLAMMATORY PROTEINS OR PROCESSES. IMPROVED ASSAYS ARE NEEDED TO MEASURE GI AND CHRONIC INFLAMMATION, AS WELL AS THE INTERACTION WITH HORMONALLY DRIVEN DEVELOPMENT AND PROLIFERATION. SEVERAL METHODS MEASURE DIVERSE EPIGENETIC CHANGES, BUT IT IS NOT CLEAR WHICH CHANGES ARE RELEVANT TO BREAST CANCER. IN ADDITION, MOST TOXICOLOGICAL ASSAYS ARE NOT CONDUCTED IN MAMMARY TISSUE, AND SO IT IS A PRIORITY TO EVALUATE IF RESULTS FROM OTHER TISSUES ARE GENERALIZABLE TO BREAST, OR TO CONDUCT ASSAYS IN BREAST TISSUE. DEVELOPING AND APPLYING THESE ASSAYS TO IDENTIFY EXPOSURES OF CONCERN WILL FACILITATE EFFORTS TO REDUCE SUBSEQUENT BREAST CANCER RISK. 2020 4 3287 60 HIERARCHICAL AND CYBERNETIC NATURE OF BIOLOGIC SYSTEMS AND THEIR RELEVANCE TO HOMEOSTATIC ADAPTATION TO LOW-LEVEL EXPOSURES TO OXIDATIVE STRESS-INDUCING AGENTS. DURING EVOLUTION IN AN AEROBIC ENVIRONMENT, MULTICELLULAR ORGANISMS SURVIVED BY ADAPTIVE RESPONSES TO BOTH THE ENDOGENOUS OXIDATIVE METABOLISM IN THE CELLS OF THE ORGANISM AND THE CHEMICALS AND LOW-LEVEL RADIATION TO WHICH THEY HAD BEEN EXPOSED. THE DEFENSE REPERTOIRE EXISTS AT ALL LEVELS OF THE BIOLOGICAL HIERARCHY--FROM THE MOLECULAR AND BIOCHEMICAL LEVEL TO THE CELLULAR AND TISSUE LEVEL TO THE ORGAN AND ORGAN SYSTEM LEVEL. CELLS CONTAIN PREVENTIVE ANTIOXIDANTS TO SUPPRESS OXIDATIVE DAMAGE TO MEMBRANES. CELLS ALSO CONTAIN PROTEINS AND DNA; BUILT-IN REDUNDANCIES FOR DAMAGED MOLECULES AND ORGANELLES; TIGHTLY COUPLED REDOX SYSTEMS; POOLS OF REDUCTANTS; ANTIOXIDANTS; DNA REPAIR MECHANISMS AND SENSITIVE SENSOR MOLECULES SUCH AS NUCLEAR FACTOR KAPPA BETA; AND SIGNAL TRANSDUCTION MECHANISMS AFFECTING BOTH TRANSCRIPTION AND POST-TRANSLATIONAL MODIFICATION OF PROTEINS NEEDED TO COPE WITH OXIDATIVE STRESS. THE BIOLOGIC CONSEQUENCES OF THE LOW-LEVEL RADIATION THAT EXCEEDS THE BACKGROUND LEVEL OF OXIDATIVE DAMAGE COULD BE NECROSIS OR APOPTOSIS, CELL PROLIFERATION, OR CELL DIFFERENTIATION. THESE EFFECTS ARE TRIGGERED BY OXIDATIVE STRESS-INDUCED SIGNAL TRANSDUCTION MECHANISMS--AN EPIGENETIC, NOT GENOTOXIC, PROCESS. IF THE END POINTS OF CELL PROLIFERATION, DIFFERENTIATION, OR CELL DEATH ARE NOT SEEN AT FREQUENCIES ABOVE BACKGROUND LEVELS IN AN ORGANISM, IT IS UNLIKELY THAT LOW-LEVEL RADIATION WOULD PLAY A ROLE IN THE MULTISTEP PROCESSES OF CHRONIC DISEASES SUCH AS CANCER. THE MECHANISM LINKED TO HOMEOSTATIC REGULATION OF PROLIFERATION AND ADAPTIVE FUNCTIONS IN A MULTICELLULAR ORGANISM COULD PROVIDE PROTECTION OF ANY ONE CELL RECEIVING DEPOSITED ENERGY BY THE RADIATION TRACT THROUGH THE SHARING OF REDUCTANTS AND BY TRIGGERING APOPTOSIS OF TARGET STEM CELLS. EXAMPLES OF THE ROLE OF GAP JUNCTIONAL INTERCELLULAR COMMUNICATION IN THE ADAPTIVE RESPONSE OF CELLS AND THE BYSTANDER EFFECT ILLUSTRATE HOW THE INTERACTION OF CELLS CAN MODULATE THE EFFECT OF RADIATION ON THE SINGLE CELL. 1998 5 3418 40 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 6 1340 39 DESIGNING SAFER DRUGS: (Q)SAR-BASED IDENTIFICATION OF MUTAGENS AND CARCINOGENS. MUTAGENICITY AND CARCINOGENICITY ARE CHRONIC EFFECTS OF PRIMARY CONCERN FOR HUMAN HEALTH. A UNIFYING APPROACH TO THEIR MECHANISTIC UNDERSTANDING IS THE RECOGNITION THAT MANY CHEMICALS PROVOKE BOTH EFFECTS BY ELECTROPHILIC ATTACK TO THE BIOLOGICAL MACROMOLECULES, AS SUCH OR AFTER METABOLISM (GENOTOXIC CARCINOGENICITY). QSARS OF INDIVIDUAL CLASSES OF GENOTOXIC CARCINOGENS HAVE CONTRIBUTED TO THE ELUCIDATION OF THE CHEMICAL DETERMINANTS OF THIS ACTIVITY. LITTLE WORK HAS BEEN DONE ON THE EPIGENETIC CARCINOGENS, ACTING THROUGH NON-GENOTOXIC, VERY SPECIFIC MECHANISMS. HOWEVER, THE EXISTING QSARS FOR INDIVIDUAL CHEMICAL CLASSES ARE TOO FEW TO BE OF REAL USEFULNESS IN THE SCREENING OF MASSES OF CANDIDATE DRUGS. MODELS FOR PREDICTING THE CARCINOGENICITY OF "ANY TYPE" OF CHEMICALS HAVE BEEN PROPOSED: PROSPECTIVE PREDICTION EXERCISES POINTED TO THE SERIOUS LIMITATIONS OF MOST OF THESE APPROACHES. THE BEST ALTERNATIVE IS PROVIDED BY PANELS OF HUMAN EXPERTS. THE ABOVE PREDICTION EXERCISES CONSIDERED SAMPLES OF GENERAL CHEMICALS, THUS WE SPECIFICALLY ADDRESSED IN THIS PAPER THE ISSUE OF PHARMACEUTICAL DRUGS. WE APPLIED OUR EXPERT KNOWLEDGE TO A DATABASE OF DRUGS WHOSE CARCINOGENICITY/NONCARCINOGENICITY STATUS WAS KNOWN. WHEREAS MOST OF THE NONCARCINOGENS WERE CORRECTLY IDENTIFIED, OUR PREDICTION OF CARCINOGENS WAS LESS SUCCESSFUL THAN WITH THE GENERAL CHEMICALS. SEVERAL CARCINOGENIC DRUGS DID NOT SHOW RECOGNIZED STRUCTURAL ALERTS, AND SUPPOSEDLY ACTED BY EPIGENETIC MECHANISMS. WHEREAS THE CONTRIBUTION OF HUMAN EXPERTS IS HIGHLY VALUABLE IN THIS PHASE (E.G. PRIORITY SETTING), MORE WORK IS NECESSARY ON: A) EPIGENETIC CARCINOGENS; B) EFFICIENT COMPUTERIZED MODELS. 2003 7 6809 30 [EPIGENETICS IN INFLAMMATORY SYSTEMIC DISEASES]. IN ADDITION TO ANALYSIS OF THE GENETIC CODE, IN RECENT YEARS MORE AND MORE STUDIES HAVE CONCENTRATED ON CHANGES IN THE EPIGENETIC CODE. EPIGENETIC MECHANISMS DETERMINE WHICH GENES IN A CELL ARE TRANSCRIBED AND THUS FORM THE PHENOTYPE OF A CELL. THE EPIGENETIC CODE CAN BE CHANGED BY ENVIRONMENTAL INFLUENCES, WHICH ALLOWS CELLS TO ADAPT TO LONGSTANDING CHANGES IN THE ENVIRONMENT. THEREFORE, IT IS FEASIBLE TO ASSUME THAT EPIGENETIC CHANGES ARE THE MOLECULAR BASIS FOR LONG-TERM EFFECTS OF THE ENVIRONMENT ON DISEASE DEVELOPMENT. IN PARTICULAR IN TUMORS AND CHRONIC INFLAMMATORY DISEASES EPIGENETIC CHANGES WERE FOUND TO CORRELATE WITH DISEASE SEVERITY AND PROGRESSION. KNOWLEDGE ABOUT THESE EPIGENETIC CHANGES MIGHT HELP THAT EPIGENETIC MODIFICATIONS CAN BE USED IN THE FUTURE AS BIOMARKERS, PROGNOSTIC FACTORS AND THERAPEUTIC TARGETS. 2014 8 2412 51 EPIGENETIC SIDE-EFFECTS OF COMMON PHARMACEUTICALS: A POTENTIAL NEW FIELD IN MEDICINE AND PHARMACOLOGY. THE TERM "EPIGENETICS" REFERS TO DNA AND CHROMATIN MODIFICATIONS THAT PERSIST FROM ONE CELL DIVISION TO THE NEXT, DESPITE A LACK OF CHANGE IN THE UNDERLYING DNA SEQUENCE. THE "EPIGENOME" REFERS TO THE OVERALL EPIGENETIC STATE OF A CELL, AND SERVES AS AN INTERFACE BETWEEN THE ENVIRONMENT AND THE GENOME. THE EPIGENOME IS DYNAMIC AND RESPONSIVE TO ENVIRONMENTAL SIGNALS NOT ONLY DURING DEVELOPMENT, BUT ALSO THROUGHOUT LIFE; AND IT IS BECOMING INCREASINGLY APPARENT THAT CHEMICALS CAN CAUSE CHANGES IN GENE EXPRESSION THAT PERSIST LONG AFTER EXPOSURE HAS CEASED. HERE WE PRESENT THE HYPOTHESIS THAT COMMONLY-USED PHARMACEUTICAL DRUGS CAN CAUSE SUCH PERSISTENT EPIGENETIC CHANGES. DRUGS MAY ALTER EPIGENETIC HOMEOSTASIS BY DIRECT OR INDIRECT MECHANISMS. DIRECT EFFECTS MAY BE CAUSED BY DRUGS WHICH AFFECT CHROMATIN ARCHITECTURE OR DNA METHYLATION. FOR EXAMPLE THE ANTIHYPERTENSIVE HYDRALAZINE INHIBITS DNA METHYLATION. AN EXAMPLE OF AN INDIRECTLY ACTING DRUG IS ISOTRETINOIN, WHICH HAS TRANSCRIPTION FACTOR ACTIVITY. A TWO-TIER MECHANISM IS POSTULATED FOR INDIRECT EFFECTS IN WHICH ACUTE EXPOSURE TO A DRUG INFLUENCES SIGNALING PATHWAYS THAT MAY LEAD TO AN ALTERATION OF TRANSCRIPTION FACTOR ACTIVITY AT GENE PROMOTERS. THIS STIMULATION RESULTS IN THE ALTERED EXPRESSION OF RECEPTORS, SIGNALING MOLECULES, AND OTHER PROTEINS NECESSARY TO ALTER GENETIC REGULATORY CIRCUITS. WITH MORE CHRONIC EXPOSURE, CELLS ADAPT BY AN UNKNOWN HYPOTHETICAL PROCESS THAT RESULTS IN MORE PERMANENT MODIFICATIONS TO DNA METHYLATION AND CHROMATIN STRUCTURE, LEADING TO ENDURING ALTERATION OF A GIVEN EPIGENETIC NETWORK. THEREFORE, ANY EPIGENETIC SIDE-EFFECT CAUSED BY A DRUG MAY PERSIST AFTER THE DRUG IS DISCONTINUED. IT IS FURTHER PROPOSED THAT SOME IATROGENIC DISEASES SUCH AS TARDIVE DYSKINESIA AND DRUG-INDUCED SLE ARE EPIGENETIC IN NATURE. IF THIS HYPOTHESIS IS CORRECT THE CONSEQUENCES FOR MODERN MEDICINE ARE PROFOUND, SINCE IT WOULD IMPLY THAT OUR CURRENT UNDERSTANDING OF PHARMACOLOGY IS AN OVERSIMPLIFICATION. WE PROPOSE THAT EPIGENETIC SIDE-EFFECTS OF PHARMACEUTICALS MAY BE INVOLVED IN THE ETIOLOGY OF HEART DISEASE, CANCER, NEUROLOGICAL AND COGNITIVE DISORDERS, OBESITY, DIABETES, INFERTILITY, AND SEXUAL DYSFUNCTION. IT IS SUGGESTED THAT A SYSTEMS BIOLOGY APPROACH EMPLOYING MICROARRAY ANALYSES OF GENE EXPRESSION AND METHYLATION PATTERNS CAN LEAD TO A BETTER UNDERSTANDING OF LONG-TERM SIDE-EFFECTS OF DRUGS, AND THAT IN THE FUTURE, EPIGENETIC ASSAYS SHOULD BE INCORPORATED INTO THE SAFETY ASSESSMENT OF ALL PHARMACEUTICAL DRUGS. THIS NEW APPROACH TO PHARMACOLOGY HAS BEEN TERMED "PHAMACOEPIGENOMICS", THE IMPACT OF WHICH MAY BE EQUAL TO OR GREATER THAN THAT OF PHARMACOGENETICS. WE PROVIDE HERE AN OVERVIEW OF THIS POTENTIALLY MAJOR NEW FIELD IN PHARMACOLOGY AND MEDICINE. 2009 9 1247 44 CURRENT EVIDENCE FOR A ROLE OF EPIGENETIC MECHANISMS IN RESPONSE TO IONIZING RADIATION IN AN ECOTOXICOLOGICAL CONTEXT. THE ISSUE OF POTENTIAL LONG-TERM OR HEREDITARY EFFECTS FOR BOTH HUMANS AND WILDLIFE EXPOSED TO LOW DOSES (OR DOSE RATES) OF IONISING RADIATION IS A MAJOR CONCERN. CHRONIC EXPOSURE TO IONISING RADIATION, DEFINED AS AN EXPOSURE OVER A LARGE FRACTION OF THE ORGANISM'S LIFESPAN OR EVEN OVER SEVERAL GENERATIONS, CAN POSSIBLY HAVE CONSEQUENCES IN THE PROGENY. RECENT WORK HAS BEGUN TO SHOW THAT EPIGENETICS PLAYS AN IMPORTANT ROLE IN ADAPTATION OF ORGANISMS CHALLENGED TO ENVIRONMENTAL STIMULAE. CHANGES TO SO-CALLED EPIGENETIC MARKS SUCH AS HISTONE MODIFICATIONS, DNA METHYLATION AND NON-CODING RNAS RESULT IN ALTERED TRANSCRIPTOMES AND PROTEOMES, WITHOUT DIRECTLY CHANGING THE DNA SEQUENCE. MOREOVER, SOME OF THESE ENVIRONMENTALLY-INDUCED EPIGENETIC CHANGES TEND TO PERSIST OVER GENERATIONS, AND THUS, EPIGENETIC MODIFICATIONS ARE REGARDED AS THE CONDUITS FOR ENVIRONMENTAL INFLUENCE ON THE GENOME. HERE, WE REVIEW THE CURRENT KNOWLEDGE OF POSSIBLE INVOLVEMENT OF EPIGENETICS IN THE CASCADE OF RESPONSES RESULTING FROM ENVIRONMENTAL EXPOSURE TO IONISING RADIATION. IN ADDITION, FROM A COMPARISON OF LAB AND FIELD OBTAINED DATA, WE INVESTIGATE EVIDENCE ON RADIATION-INDUCED CHANGES IN THE EPIGENOME AND IN PARTICULAR THE TOTAL OR LOCUS SPECIFIC LEVELS OF DNA METHYLATION. THE CHALLENGES FOR FUTURE RESEARCH AND POSSIBLE USE OF CHANGES AS AN EARLY WARNING (BIOMARKER) OF RADIOSENSITIVITY AND INDIVIDUAL EXPOSURE IS DISCUSSED. SUCH A BIOMARKER COULD BE USED TO DETECT AND BETTER UNDERSTAND THE MECHANISMS OF TOXIC ACTION AND INTER/INTRA-SPECIES SUSCEPTIBILITY TO RADIATION WITHIN AN ENVIRONMENTAL RISK ASSESSMENT AND MANAGEMENT CONTEXT. 2019 10 1844 44 EFFECTS OF THE LIFESTYLE HABITS IN BREAST CANCER TRANSCRIPTIONAL REGULATION. THROUGH RESEARCH CARRIED OUT IN THE LAST 25 YEARS ABOUT THE BREAST CANCER ETIOLOGY, IT HAS BEEN POSSIBLE TO ESTIMATE THAT LESS THAN 10 % OF PATIENTS WHO ARE DIAGNOSED WITH THE CONDITION ARE CARRIERS OF SOME GERMLINE OR SOMATIC MUTATION. THE CLINICAL REPORTS OF BREAST CANCER PATIENTS WITH HEALTHY TWINS AND THE DEVELOPMENT OF DISEASE IN WOMEN WITHOUT HIGH PENETRANCE MUTATIONS DETECTED, WARN THE PARTICIPATION MORE FACTORS IN THE TRANSFORMATION PROCESS. THE HIGH INCIDENCE OF MAMMARY ADENOCARCINOMA IN THE MODERN WOMAN AND THE URGENT NEED FOR NEW METHODS OF PREVENTION AND EARLY DETECTION HAVE DEMANDED MORE INFORMATION ABOUT THE ROLE THAT ENVIRONMENT AND LIFESTYLE HAVE ON THE TRANSFORMATION OF MAMMARY GLAND EPITHELIAL CELLS. OBESITY, ALCOHOLISM AND SMOKING ARE FACTORS THAT HAVE SHOWN A CLOSE CORRELATION WITH THE RISK OF DEVELOPING BREAST CANCER. AND ALTHOUGH THESE CONDITIONS AFFECT DIFFERENT CELL REGULATION LEVELS, THE STUDY OF ITS EFFECTS IN THE MECHANISMS OF TRANSCRIPTIONAL AND EPIGENETIC REGULATION IS CONSIDERED CRITICAL FOR A BETTER UNDERSTANDING OF THE LOSS OF IDENTITY OF EPITHELIAL CELLS DURING CARCINOGENESIS OF THIS TISSUE. THE MAIN OBJECTIVE OF THIS REVIEW WAS TO ESTABLISH THE IMPORTANCE OF CHANGES OCCURRING TO TRANSCRIPTIONAL LEVEL IN THE MAMMARY GLAND AS A CONSEQUENCE OF ACUTE OR CHRONIC EXPOSURE TO HARMFUL PRODUCTS SUCH AS OBESITY-CAUSING FOODS, ETHANOL AND CIGARETTE SMOKE COMPONENTS. AT ANALYZE THE MAIN STUDIES RELATED TO TOPIC, IT HAS CONCLUDED THAT THE UNDERSTANDING OF EFFECTS CAUSED BY THE LIFESTYLE FACTORS IN PERFORMANCE OF THE TRANSCRIPTIONAL MECHANISMS THAT DETERMINE GENE EXPRESSION OF THE MAMMARY GLAND EPITHELIAL CELLS, MAY HELP EXPLAIN THE DEVELOPMENT OF THIS DISEASE IN WOMEN WITHOUT GENETIC PROPENSITY AND DIFFERENT PHENOTYPIC MANIFESTATIONS OF THIS CANCER TYPE. 2016 11 389 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 12 6656 37 UPDATED UNDERSTANDING OF CANCER AS A METABOLIC AND TELOMERE-DRIVEN DISEASE, AND PROPOSAL FOR COMPLEX PERSONALIZED TREATMENT, A HYPOTHESIS. IN THIS REVIEW, WE PROPOSE A HOLISTIC APPROACH TO UNDERSTANDING CANCER AS A METABOLIC DISEASE. OUR SEARCH FOR RELEVANT STUDIES IN MEDICAL DATABASES CONCLUDES THAT CANCER CELLS DO NOT EVOLVE DIRECTLY FROM NORMAL HEALTHY CELLS. WE HYPOTHESIZE THAT ABERRANT DNA DAMAGE ACCUMULATES OVER TIME-AVOIDING THE NATURAL DNA CONTROLS THAT OTHERWISE REPAIR OR REPLACE THE RAPIDLY REPLICATING CELLS. DNA DAMAGE STARTS TO ACCUMULATE IN NON-REPLICATING CELLS, LEADING TO SENESCENCE AND AGING. DNA DAMAGE IS LINKED WITH GENETIC AND EPIGENETIC FACTORS, BUT THE DEVELOPMENT OF CANCER IS FAVORED BY TELOMERASE ACTIVITY. EVIDENCE INDICATES THAT TELOMERE LENGTH IS AFFECTED BY CHRONIC INFLAMMATIONS, ALTERATIONS OF MITOCHONDRIAL DNA, AND VARIOUS ENVIRONMENTAL FACTORS. EMOTIONAL STRESS ALSO INFLUENCES TELOMERE LENGTH. CHRONIC INFLAMMATION CAN CAUSE OXIDATIVE DNA DAMAGE. OXIDATIVE STRESS, IN TURN, CAN TRIGGER MITOCHONDRIAL CHANGES, WHICH ULTIMATELY ALTER NUCLEAR GENE EXPRESSION. THIS VICIOUS CYCLE HAS LED SEVERAL SCIENTISTS TO VIEW CANCER AS A METABOLIC DISEASE. WE HAVE PROPOSED COMPLEX PERSONALIZED TREATMENTS THAT SEEK TO CORRECT MULTIPLE CHANGES SIMULTANEOUSLY USING A PSYCHOLOGICAL APPROACH TO REDUCE CHRONIC STRESS, IMMUNE CHECKPOINT THERAPY WITH REDUCED DOSES OF CHEMO AND RADIOTHERAPY, MINIMAL SURGICAL INTERVENTION, IF ANY, AND MITOCHONDRIAL METABOLIC REPROGRAMMING PROTOCOLS SUPPLEMENTED BY INTERMITTENT FASTING AND PERSONALIZED DIETARY PLANS WITHOUT INTERFERING WITH THE OTHER THERAPIES. 2020 13 6459 22 TIME TO CHANGE FROM A SIMPLE LINEAR MODEL TO A COMPLEX SYSTEMS MODEL. A SIMPLE LINEAR MODEL TO TEST THE HYPOTHESIS BASED ON ONE-ON-ONE RELATIONSHIP HAS BEEN USED TO FIND THE CAUSATIVE FACTORS OF DISEASES. HOWEVER, WE NOW KNOW THAT NOT JUST ONE, BUT MANY FACTORS FROM DIFFERENT SYSTEMS SUCH AS CHEMICAL EXPOSURE, GENES, EPIGENETIC CHANGES, AND PROTEINS ARE INVOLVED IN THE PATHOGENESIS OF CHRONIC DISEASES SUCH AS DIABETES MELLITUS. SO, WITH AVAILABILITY OF MODERN TECHNOLOGIES TO UNDERSTAND THE INTRICATE NATURE OF RELATIONS AMONG COMPLEX SYSTEMS, WE NEED TO MOVE FORWARD TO THE FUTURE BY TAKING COMPLEX SYSTEMS MODEL. 2016 14 761 40 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 15 3123 36 GETTING AN INSIGHT INTO THE COMPLEXITY OF MAJOR CHRONIC INFLAMMATORY AND DEGENERATIVE DISEASES: A POTENTIAL NEW SYSTEMIC APPROACH TO THEIR TREATMENT. AS THE MODERN SOCIETY IS TROUBLED BY MULTI-FACTORIAL DISEASES, RESEARCH HAS BEEN CONDUCTED ON COMPLEX REALITIES INCLUDING CHRONIC INFLAMMATION, CANCER, OBESITY, HIV INFECTION, METABOLIC SYNDROME AND ITS DETRIMENTAL CARDIOVASCULAR COMPLICATIONS AS WELL AS DEPRESSION AND OTHER BRAIN DISORDERS. DETERIORATION OF CRUCIAL HOMEOSTATIC MECHANISMS IN SUCH DISEASES INVARIABLY RESULTS IN ACTIVATION OF INFLAMMATORY MEDIATORS, CHRONIC INFLAMMATION, LOSS IN IMMUNOLOGICAL FUNCTION, INCREASED SUSCEPTIBILITY TO DISEASES, ALTERATION OF METABOLISM, DECREASE OF ENERGY PRODUCTION AND NEURO-COGNITIVE DECLINE. REGULATION OF GENES EXPRESSION BY EPIGENETIC CODE IS THE DOMINANT MECHANISM FOR THE TRANSDUCTION OF ENVIRONMENTAL INPUTS, SUCH AS STRESS AND INFLAMMATION TO LASTING PHYSIOLOGICAL CHANGES. ACUTE AND CHRONIC STRESS DETERMINES DNA METHYLATION AND HISTONE MODIFICATIONS IN BRAIN REGIONS WHICH MAY CONTRIBUTE TO NEURO-DEGENERATIVE DISORDERS. NUCLEAR GLUCOCORTICOIDS RECEPTOR INTERACTS WITH THE EPIGENOMA RESULTING IN A CORTISOL RESISTANCE STATUS ASSOCIATED WITH A DETERIORATION OF THE METABOLIC AND IMMUNE FUNCTIONS. GONADAL STEROIDS RECEPTORS HAVE A SIMILAR CAPACITY TO PRODUCE EPIGENOMIC REORGANIZATION OF CHROMATINE STRUCTURE. EPIGENOMIC-INDUCED REDUCTION IN IMMUNE CELLS TELOMERES LENGTH HAS BEEN OBSERVED IN MANY DEGENERATIVE DISEASES, INCLUDING ALL TYPES OF CANCER. THE FINAL RESULT OF THESE EPIGENETIC ALTERATIONS IS A SERIOUS DAMAGE TO THE NEURO-ENDOCRINE-IMMUNE-METABOLIC ADAPTIVE SYSTEMS. IN THIS STUDY, WE PROPOSE A TREATMENT WITH STEM CELLS DIFFERENTIATION STAGE FACTORS TAKEN FROM ZEBRAFISH EMBRYOS WHICH ARE ABLE TO REGULATE THE GENES EXPRESSION OF NORMAL AND PATHOLOGICAL STEM CELLS IN A DIFFERENT SPECIFIC WAY. 2015 16 3210 39 HEALTH EFFECTS ASSOCIATED WITH PRE- AND PERINATAL EXPOSURE TO ARSENIC. INORGANIC ARSENIC IS A WELL-ESTABLISHED HUMAN CARCINOGEN, ABLE TO INDUCE GENETIC AND EPIGENETIC ALTERATIONS. MORE THAN 200 MILLION PEOPLE WORLDWIDE ARE EXPOSED TO ARSENIC CONCENTRATIONS IN DRINKING WATER EXCEEDING THE RECOMMENDED WHO THRESHOLD (10MUG/L). ADDITIONALLY, CHRONIC EXPOSURE TO LEVELS BELOW THIS THRESHOLD IS KNOWN TO RESULT IN LONG-TERM HEALTH EFFECTS IN HUMANS. THE ARSENIC-RELATED HEALTH EFFECTS IN HUMANS ARE ASSOCIATED WITH ITS BIOTRANSFORMATION PROCESS, WHEREBY THE RESULTING METABOLITES CAN INDUCE MOLECULAR DAMAGE THAT ACCUMULATES OVER TIME. THE EFFECTS DERIVED FROM THESE ALTERATIONS INCLUDE GENOMIC INSTABILITY ASSOCIATED WITH OXIDATIVE DAMAGE, ALTERATION OF GENE EXPRESSION (INCLUDING CODING AND NON-CODING RNAS), GLOBAL AND LOCALIZED EPIGENETIC REPROGRAMMING, AND HISTONE POSTTRANSLATIONAL MODIFICATIONS. THESE ALTERATIONS DIRECTLY AFFECT MOLECULAR PATHWAYS INVOLVED IN THE ONSET AND PROGRESSION OF MANY CONDITIONS THAT CAN ARISE EVEN DECADES AFTER THE EXPOSURE OCCURS. IMPORTANTLY, ARSENIC METABOLITES GENERATED DURING ITS BIOTRANSFORMATION CAN ALSO PASS THROUGH THE PLACENTAL BARRIER, RESULTING IN FETAL EXPOSURE TO THIS CARCINOGEN AT SIMILAR LEVELS TO THOSE OF THE MOTHER. AS SUCH, MORE IMMEDIATE EFFECTS OF THE ARSENIC-INDUCED MOLECULAR DAMAGE CAN BE OBSERVED AS DETRIMENTAL EFFECTS ON FETAL DEVELOPMENT, PREGNANCY, AND BIRTH OUTCOMES. IN THIS REVIEW, WE FOCUS ON THE GENETIC AND EPIGENETIC DAMAGE ASSOCIATED WITH EXPOSURE TO LOW LEVELS OF ARSENIC, PARTICULARLY THOSE AFFECTING EARLY DEVELOPMENTAL STAGES. WE ALSO PRESENT HOW THESE ALTERATIONS OCCURRING DURING EARLY LIFE CAN IMPACT THE DEVELOPMENT OF CERTAIN DISEASES IN ADULT LIFE. 2021 17 795 42 CELLULAR RESILIENCE. CELLULAR RESILIENCE DESCRIBES THE ABILITY OF A CELL TO COPE WITH ENVIRONMENTAL CHANGES SUCH AS TOXICANT EXPOSURE. IF CELLULAR METABOLISM DOES NOT COLLAPSE DIRECTLY AFTER THE HIT OR END IN PROGRAMMED CELL DEATH, THE ENSUING STRESS RESPONSES PROMOTE A NEW HOMEOSTASIS UNDER STRESS. THE PROCESSES OF REVERTING "BACK TO NORMAL" AND REVERSAL OF APOPTOSIS ("ANASTASIS") HAVE BEEN STUDIED LITTLE AT THE CELLULAR LEVEL. CELL TYPES SHOW ASTONISHINGLY SIMILAR VULNERABILITY TO MOST TOXICANTS, EXCEPT FOR THOSE THAT REQUIRE A VERY SPECIFIC TARGET, METABOLISM OR MECHANISM PRESENT ONLY IN SPECIFIC CELL TYPES. THE MAJORITY OF CHEMICALS TRIGGERS "GENERAL CYTOTOXICITY" IN ANY CELL AT SIMILAR CONCENTRATIONS. WE HYPOTHESIZE THAT CELLS DIFFER LESS IN THEIR VULNERABILITY TO A GIVEN TOXICANT THAN IN THEIR RESILIENCE (COPING WITH THE "HIT"). IN MANY CASES, CELLS DO NOT RETURN TO THE NAIVE STATE AFTER A TOXIC INSULT. THE PHENOMENA OF "PRE-CONDITIONING", "TOLERANCE" AND "HORMESIS" DESCRIBE THIS FOR LOW-DOSE EXPOSURES TO TOXICANTS THAT RENDER THE CELL MORE RESISTANT TO SUBSEQUENT HITS. THE DEFENSE AND RESILIENCE PROGRAMS INCLUDE EPIGENETIC CHANGES THAT LEAVE A "MEMORY/SCAR" - AN ALTERATION AS A CONSEQUENCE OF THE STRESS THE CELL HAS EXPERIENCED. THESE MEMORIES MIGHT HAVE LONG-TERM CONSEQUENCES, BOTH POSITIVE (RESISTANCE) AND NEGATIVE, THAT CONTRIBUTE TO CHRONIC AND DELAYED MANIFESTATIONS OF HAZARD AND, ULTIMATELY, DISEASE. THIS ARTICLE CALLS FOR MORE SYSTEMATIC ANALYSES OF HOW CELLS COPE WITH TOXIC PERTURBATIONS IN THE LONG-TERM AFTER STRESSOR WITHDRAWAL. A TECHNICAL PREREQUISITE FOR THESE ARE STABLE (ORGANOTYPIC) CULTURES AND A CHARACTERIZATION OF STRESS RESPONSE MOLECULAR NETWORKS. 2015 18 5119 43 POSSIBLE CONTRIBUTION OF CHRONIC INFLAMMATION IN THE INDUCTION OF CANCER IN RHEUMATIC DISEASES. SEVERAL CHRONIC INFLAMMATORY CONDITIONS AND AUTOIMMUNE DISEASES INVOLVING DIFFERENT ORGANS AND TISSUES HAVE BEEN FOUND AT RISK OF PROGRESSION TO CANCER. A WIDE ARRAY OF PROINFLAMMATORY CYTOKINES, PROSTAGLANDINS, NITRIC OXIDE PRODUCTS, AND MATRICELLULAR PROTEINS ARE CLOSELY INVOLVED IN PREMALIGNANT AND MALIGNANT TRANSITION OF CELLS ALMOST ALWAYS IN A BACKGROUND OF CHRONIC INFLAMMATION. INTERESTINGLY, EPIGENETIC PERTURBATIONS (I.E. MIRNA ABERRATIONS, ALTERED DNA METHYLATION) TOGETHER WITH IMPORTANT STEROID HORMONE METABOLIC CHANGES (I.E. OESTROGENS), OR THE ALTERED VITAMIN D CONCENTRATIONS THAT MAY UNBALANCE THE IMMUNE / INFLAMMATORY RESPONSE, HAVE BEEN FOUND LINKED TO THE RISK AND SEVERITY IN SEVERAL CHRONIC INFLAMMATORY CONDITIONS, AS WELL AS IN CANCER. IN PARTICULAR, IT IS EVIDENT, THAT NOT ONLY THE PARENT OESTROGEN BUT ALSO OESTROGEN METABOLITES SHOULD BE TAKEN INTO ACCOUNT WHEN THIS PROCESS IS EVALUATED, SPECIALLY THE FORMATION OF CATECHOLOESTROGEN METABOLITES, THAT ARE CAPABLE OF FORMING EITHER STABLE OR DEPURINATING DNA ADDUCTS, WHICH CAN CAUSE EXTENSIVE DNA DAMAGE. IT IS INTERESTING THAT TODAY THE SUCCESSFUL TREATMENT OF SEVERAL CHRONIC IMMUNE/INFLAMMATORY RHEUMATIC DISEASES IS OBTAINED ALSO BY USING MEDICATIONS INITIALLY DEVELOPED FOR THEIR USE IN ONCOLOGY. THE CIRCADIAN INCREASE OF GROWTH FACTORS, SPECIALLY DURING THE LATE NIGHT, IN BOTH CHRONIC INFLAMMATION AND IN CANCER PATIENTS, AS WELL AS THE PRESENCE OF OESTROGEN-REGULATED CIRCADIAN MECHANISMS, SUGGESTS FURTHER IMPORTANT LINKS. 2014 19 1360 41 DEVELOPMENTAL ASPECTS OF A LIFE COURSE APPROACH TO HEALTHY AGEING. WE EXAMINE THE MECHANISTIC BASIS AND WIDER IMPLICATIONS OF ADOPTING A DEVELOPMENTAL PERSPECTIVE ON HUMAN AGEING. PREVIOUS MODELS OF AGEING HAVE CONCENTRATED ON ITS GENETIC BASIS, OR THE DETRIMENTAL EFFECTS OF ACCUMULATED DAMAGE, BUT ALSO HAVE RAISED ISSUES ABOUT WHETHER AGEING CAN BE VIEWED AS ADAPTIVE ITSELF, OR IS A CONSEQUENCE OF OTHER ADAPTIVE PROCESSES, FOR EXAMPLE IF MAINTENANCE AND REPAIR PROCESSES IN THE PERIOD UP TO REPRODUCTION ARE TRADED OFF AGAINST LATER DECLINE IN FUNCTION. A LIFE COURSE MODEL PLACES AGEING IN THE CONTEXT OF THE ATTAINMENT OF PEAK CAPACITY FOR A BODY SYSTEM, STARTING IN EARLY DEVELOPMENT WHEN PLASTICITY PERMITS CHANGES IN STRUCTURE AND FUNCTION INDUCED BY A RANGE OF ENVIRONMENTAL STIMULI, FOLLOWED BY A PERIOD OF DECLINE, THE RATE OF WHICH DEPENDS ON THE PEAK ATTAINED AS WELL AS THE LATER LIFE CONDITIONS. SUCH PATH DEPENDENCY IN THE RATE OF AGEING MAY OFFER NEW INSIGHTS INTO ITS MODIFICATION. FOCUSING ON MUSCULOSKELETAL AND CARDIOVASCULAR FUNCTION, WE DISCUSS THIS MODEL AND THE POSSIBLE UNDERLYING MECHANISMS, INCLUDING ENDOTHELIAL FUNCTION, OXIDATIVE STRESS, STEM CELLS AND NUTRITIONAL FACTORS SUCH AS VITAMIN D STATUS. EPIGENETIC CHANGES INDUCED DURING DEVELOPMENTAL PLASTICITY, AND IMMUNE FUNCTION MAY PROVIDE A COMMON MECHANISTIC PROCESS UNDERLYING A LIFE COURSE MODEL OF AGEING. THE LIFE COURSE TRAJECTORY DIFFERS IN HIGH AND LOW RESOURCE SETTINGS. NEW INSIGHTS INTO THE DEVELOPMENTAL COMPONENTS OF THE LIFE COURSE MODEL OF AGEING MAY LEAD TO THE DESIGN OF BIOMARKERS OF LATER CHRONIC DISEASE RISK AND TO NEW INTERVENTIONS TO PROMOTE HEALTHY AGEING, WITH IMPORTANT IMPLICATIONS FOR PUBLIC HEALTH. 2016 20 5557 42 ROLE OF GENOMIC INSTABILITY IN ARSENIC-INDUCED CARCINOGENICITY. A REVIEW. EXPOSURE TO CHRONIC ARSENIC TOXICITY IS ASSOCIATED WITH CANCER. ALTHOUGH UNSTABLE GENOME IS A CHARACTERISTIC FEATURE OF CANCER CELLS, THE MECHANISMS LEADING TO GENOMIC INSTABILITY IN ARSENIC-INDUCED CARCINOGENESIS ARE POORLY UNDERSTOOD. WHILE THERE ARE EXCELLENT REVIEWS RELATING TO GENOMIC INSTABILITY IN GENERAL, THERE IS NO COMPREHENSIVE REVIEW PRESENTING THE MECHANISMS INVOLVED IN ARSENIC-INDUCED GENOMIC INSTABILITY. THIS REVIEW WAS UNDERTAKEN TO PRESENT THE CURRENT STATE OF RESEARCH IN THIS AREA AND TO HIGHLIGHT THE MAJOR MECHANISMS THAT MAY INVOLVED IN ARSENIC-INDUCED GENOMIC INSTABILITY LEADING TO CANCER. GENOMIC INSTABILITY IS BROADLY CLASSIFIED INTO CHROMOSOMAL INSTABILITY (CIN), PRIMARILY ASSOCIATED WITH MITOTIC ERRORS; AND MICROSATELLITE INSTABILITY (MIN), ASSOCIATED WITH DNA LEVEL INSTABILITY. ARSENIC-INDUCED GENOMIC INSTABILITY IS ESSENTIALLY MULTI-FACTORIAL IN NATURE AND INVOLVES MOLECULAR CROSS-TALK ACROSS SEVERAL CELLULAR PATHWAYS, AND IS MODULATED BY A NUMBER OF ENDOGENOUS AND EXOGENOUS FACTORS. ARSENIC AND ITS METABOLITES GENERATE OXIDATIVE STRESS, WHICH IN TURN INDUCES GENOMIC INSTABILITY THROUGH DNA DAMAGE, IRREVERSIBLE DNA REPAIR, TELOMERE DYSFUNCTION, MITOTIC ARREST AND APOPTOSIS. IN ADDITION TO GENETIC ALTERATION; EPIGENETIC REGULATION THROUGH PROMOTER METHYLATION AND MIRNA EXPRESSION ALTERS GENE EXPRESSION PROFILING LEADING TO GENOME MORE VULNERABLE AND UNSTABLE TOWARDS CANCER RISK. MOREOVER, MUTATIONS OR SILENCING OF PRO-APOPTOTIC GENES CAN LEAD TO GENOMIC INSTABILITY BY ALLOWING SURVIVAL OF DAMAGED CELLS THAT WOULD OTHERWISE DIE. ALTHOUGH A LARGE BODY OF INFORMATION IS NOW GENERATED REGARDING ARSENIC-INDUCED CARCINOGENESIS; FURTHER STUDIES EXPLORING GENOME-WIDE ASSOCIATION, ROLE OF ENVIRONMENT AND DIET ARE NEEDED FOR A BETTER UNDERSTANDING OF THE ARSENIC-INDUCED GENOMIC INSTABILITY. 2013