1 259 139 ADVANCES IN PCOS PATHOGENESIS AND PROGRESSION-MITOCHONDRIAL MUTATIONS AND DYSFUNCTION. POLYCYSTIC OVARY SYNDROME (PCOS) IS A COMMON FEMALE ENDOCRINE DISORDER, WHICH STILL REMAINS LARGELY UNSOLVED IN TERMS OF ETIOLOGY AND PATHOGENESIS DESPITE IMPORTANT ADVANCES IN OUR UNDERSTANDING OF ITS GENETIC, EPIGENETIC, OR ENVIRONMENTAL FACTOR IMPLICATIONS. IT IS A HETEROGENEOUS DISEASE, FREQUENTLY ASSOCIATED WITH INSULIN RESISTANCE, CHRONIC INFLAMMATION, AND OXIDATIVE STRESS AND PROBABLY ACCOMPANIED WITH SUBCLINICAL CARDIOVASCULAR DISEASE (CVD) AND SOME MALIGNANT LESIONS AS WELL, SUCH AS ENDOMETRIAL CANCER. DISCREPANCIES IN THE CLINICAL PHENOTYPE AND PROGRESSION OF PCOS EXIST BETWEEN DIFFERENT POPULATION GROUPS, WHICH NUCLEAR GENETIC STUDIES HAVE SO FAR FAILED TO EXPLAIN. OVER THE LAST YEARS, MITOCHONDRIAL DYSFUNCTION HAS BEEN INCREASINGLY RECOGNIZED AS AN IMPORTANT CONTRIBUTOR TO AN ARRAY OF DISEASES. BECAUSE MITOCHONDRIA ARE UNDER THE DUAL GENETIC CONTROL OF BOTH THE MITOCHONDRIAL AND NUCLEAR GENOMES, MUTATIONS WITHIN EITHER DNA MOLECULE MAY RESULT IN DEFICIENCY IN RESPIRATORY CHAIN FUNCTION THAT LEADS TO A REDUCED ABILITY TO PRODUCE CELLULAR ADENOSINE-5'-TRIPHOSPHATE AND TO AN EXCESSIVE PRODUCTION OF REACTIVE OXYGEN SPECIES. HOWEVER, THE ASSOCIATION BETWEEN VARIANTS IN MITOCHONDRIAL GENOME, MITOCHONDRIAL DYSFUNCTION, AND PCOS HAS BEEN INVESTIGATED TO A LESSER EXTENT. MAY MUTATIONS IN MITOCHONDRIAL DNA (MTDNA) BECOME AN ADDITIONAL TARGET OF INVESTIGATIONS ON THE MISSING PCOS HERITABILITY? ARE MUTATIONS IN MTDNA IMPLICATED IN THE INITIATION AND PROGRESSION OF PCOS COMPLICATIONS, E.G., CVDS, DIABETES MELLITUS, CANCERS? 2018 2 6116 31 THE EPIGENETIC CORRELATION AMONG OVARIAN CANCER, ENDOMETRIOSIS AND PCOS: A REVIEW. OVARIAN CANCER IS A FREQUENT MALIGNANCY THAT AFFECTS A LARGE PERCENTAGE OF WOMEN. ENDOMETRIOSIS IS A CHRONIC CONDITION, WHERE THERE IS A PRODUCTION OF BENIGN LESIONS WERE OBSERVED IN THE UTERINE ENVIRONMENT. PCOS IS A METABOLIC DISORDER CHARACTERIZED BY THE PRESENCE OF NUMEROUS CYSTS IN THE OVARIES. THE RELATION BETWEEN OVARIAN MALIGNANCIES AND PCOS, BY AN INCREASED RATIO OF OVARIAN STROMAL TISSUES IN PCOS PATIENTS. THE DIRECT CORRELATION IS NOT YET CONFIRMED AMONG THE THREE DISORDERS, BUT IT IS OFTEN NOTED THAT THEY SHARE RISK FACTORS, SUCH AS OBESITY, HORMONAL IMBALANCES. EPIGENETIC FACTORS HAVE SHOWN TO BE AN IMPORTANT REASON FOR CANCER PROGRESSION. OUR FINDINGS AT THE EPIGENETIC LEVEL INCLUDES A COMPARATIVE ANALYSIS, POINT MUTATIONS IN GENES, OVERACTIVATION OF SIGNALING PATHWAYS. THIS REVIEW PAPER, HIGHLIGHT THE POSSIBLE CORRELATION BETWEEN THE THREE DISORDERS IN TERMS OF GENETIC AND EPIGENETIC FACTORS AND HOW IT COULD TOGETHER TRIGGER THE CANCER PROGRESSION AND METASTASIS. 2022 3 6067 48 THE DIABETES MELLITUS-ATHEROSCLEROSIS CONNECTION: THE ROLE OF LIPID AND GLUCOSE METABOLISM AND CHRONIC INFLAMMATION. DIABETES MELLITUS COMPRISES A GROUP OF CARBOHYDRATE METABOLISM DISORDERS THAT SHARE A COMMON MAIN FEATURE OF CHRONIC HYPERGLYCEMIA THAT RESULTS FROM DEFECTS OF INSULIN SECRETION, INSULIN ACTION, OR BOTH. INSULIN IS AN IMPORTANT ANABOLIC HORMONE, AND ITS DEFICIENCY LEADS TO VARIOUS METABOLIC ABNORMALITIES IN PROTEINS, LIPIDS, AND CARBOHYDRATES. ATHEROSCLEROSIS DEVELOPS AS A RESULT OF A MULTISTEP PROCESS ULTIMATELY LEADING TO CARDIOVASCULAR DISEASE ASSOCIATED WITH HIGH MORBIDITY AND MORTALITY. ALTERATION OF LIPID METABOLISM IS A RISK FACTOR AND CHARACTERISTIC FEATURE OF ATHEROSCLEROSIS. POSSIBLE LINKS BETWEEN THE TWO CHRONIC DISORDERS DEPENDING ON ALTERED METABOLIC PATHWAYS HAVE BEEN INVESTIGATED IN NUMEROUS STUDIES. IT WAS SHOWN THAT BOTH TYPES OF DIABETES MELLITUS CAN ACTUALLY INDUCE ATHEROSCLEROSIS DEVELOPMENT OR FURTHER ACCELERATE ITS PROGRESSION. ELEVATED GLUCOSE LEVEL, DYSLIPIDEMIA, AND OTHER METABOLIC ALTERATIONS THAT ACCOMPANY THE DISEASE DEVELOPMENT ARE TIGHTLY INVOLVED IN THE PATHOGENESIS OF ATHEROSCLEROSIS AT ALMOST EVERY STEP OF THE ATHEROGENIC PROCESS. CHRONIC INFLAMMATION IS CURRENTLY CONSIDERED AS ONE OF THE KEY FACTORS IN ATHEROSCLEROSIS DEVELOPMENT AND IS PRESENT STARTING FROM THE EARLIEST STAGES OF THE PATHOLOGY INITIATION. IT MAY ALSO BE REGARDED AS ONE OF THE POSSIBLE LINKS BETWEEN ATHEROSCLEROSIS AND DIABETES MELLITUS. HOWEVER, THE DATA AVAILABLE SO FAR DO NOT ALLOW FOR DEVELOPING EFFECTIVE ANTI-INFLAMMATORY THERAPEUTIC STRATEGIES THAT WOULD STOP ATHEROSCLEROTIC LESION PROGRESSION OR INDUCE LESION REDUCTION. IN THIS REVIEW, WE SUMMARIZE THE MAIN ASPECTS OF DIABETES MELLITUS THAT POSSIBLY AFFECT THE ATHEROGENIC PROCESS AND ITS RELATIONSHIP WITH CHRONIC INFLAMMATION. WE ALSO DISCUSS THE ESTABLISHED PATHOPHYSIOLOGICAL FEATURES THAT LINK ATHEROSCLEROSIS AND DIABETES MELLITUS, SUCH AS OXIDATIVE STRESS, ALTERED PROTEIN KINASE SIGNALING, AND THE ROLE OF CERTAIN MIRNA AND EPIGENETIC MODIFICATIONS. 2020 4 6812 32 [EPIGENETICS, INTERFACE BETWEEN ENVIRONMENT AND GENES: ROLE IN COMPLEX DISEASES]. EPIGENETICS IS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION OR CELLULAR PHENOTYPE CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE. EPIGENETICS IS ONE OF THE MAJOR MECHANISMS EXPLAINING THE "DEVELOPMENTAL ORIGIN OF HEALTH AND DISEASES" (DOHAD). BESIDES GENETIC BACKGROUND INHERITED FROM PARENTS, WHICH CONFERS SUSCEPTIBILITY TO CERTAIN PATHOLOGIES, EPIGENETIC CHANGES CONSTITUTE THE MEMORY OF PREVIOUS EVENTS, EITHER POSITIVE OR NEGATIVE, ALONG THE LIFE CYCLE, INCLUDING AT THE IN UTERO STAGE. THE LATER EXPOSITION TO HOSTILE ENVIRONMENT MAY REVEAL SUCH SUSCEPTIBILITY, WITH THE DEVELOPMENT OF VARIOUS PATHOLOGIES, AMONG THEM NUMEROUS CHRONIC COMPLEX DISEASES. THE DEMONSTRATION OF SUCH A SEQUENCE OF EVENTS HAS BEEN SHOWN FOR METABOLIC DISEASES AS OBESITY, METABOLIC SYNDROME AND TYPE 2 DIABETES, CARDIOVASCULAR DISEASE AND CANCER. IN CONTRAST TO GENETIC PREDISPOSITION, WHICH IS IRREVERSIBLE, EPIGENETIC CHANGES ARE POTENTIALLY REVERSIBLE, THUS GIVING TARGETS NOT ONLY FOR PREVENTION, BUT POSSIBLY ALSO FOR THE TREATMENT OF CERTAIN COMPLEX DISEASES. 2012 5 4273 34 MICROBIOTA AND EPIGENETICS: HEALTH IMPACT. EPIGENETIC CHANGES ASSOCIATED WITH DISEASE DEVELOPMENT AND PROGRESSIONS ARE OF INCREASING IMPORTANCE BECAUSE OF THEIR POTENTIAL DIAGNOSTIC AND THERAPEUTIC APPLICATIONS. SEVERAL EPIGENETIC CHANGES ASSOCIATED WITH CHRONIC METABOLIC DISORDERS HAVE BEEN STUDIED IN VARIOUS DISEASES. EPIGENETIC CHANGES ARE MOSTLY MODULATED BY ENVIRONMENTAL FACTORS, INCLUDING THE HUMAN MICROBIOTA LIVING IN DIFFERENT PARTS OF OUR BODIES. THE MICROBIAL STRUCTURAL COMPONENTS AND THE MICROBIALLY DERIVED METABOLITES DIRECTLY INTERACT WITH HOST CELLS, THEREBY MAINTAINING HOMEOSTASIS. MICROBIOME DYSBIOSIS, ON THE OTHER HAND, IS KNOWN TO PRODUCE ELEVATED LEVELS OF DISEASE-LINKED METABOLITES, WHICH MAY DIRECTLY AFFECT A HOST METABOLIC PATHWAY OR INDUCE EPIGENETIC CHANGES THAT CAN LEAD TO DISEASE DEVELOPMENT. DESPITE THEIR IMPORTANT ROLE IN HOST PHYSIOLOGY AND SIGNAL TRANSDUCTION, THERE HAS BEEN LITTLE RESEARCH INTO THE MECHANICS AND PATHWAYS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. THIS CHAPTER FOCUSES ON THE RELATIONSHIP BETWEEN MICROBES AND THEIR EPIGENETIC EFFECTS IN DISEASED PATHOLOGY, AS WELL AS ON THE REGULATION AND METABOLISM OF THE DIETARY OPTIONS AVAILABLE TO THE MICROBES. FURTHERMORE, THIS CHAPTER ALSO PROVIDES A PROSPECTIVE LINK BETWEEN THESE TWO IMPORTANT PHENOMENA, TERMED "MICROBIOME AND EPIGENETICS." 2023 6 5373 37 RECENT ADVANCES IN UNDERSTANDING THE ROLE OF DIET AND OBESITY IN THE DEVELOPMENT OF COLORECTAL CANCER. COLORECTAL CANCER (CRC) IS A MAJOR CAUSE OF PREMATURE DEATH IN THE UK AND MANY DEVELOPED COUNTRIES. HOWEVER, THE RISK OF DEVELOPING CRC IS WELL RECOGNISED TO BE ASSOCIATED NOT ONLY WITH DIET BUT ALSO WITH OBESITY AND LACK OF EXERCISE. WHILE EPIDEMIOLOGICAL EVIDENCE SHOWS AN ASSOCIATION WITH FACTORS SUCH AS HIGH RED MEAT INTAKE AND LOW INTAKE OF VEGETABLES, FIBRE AND FISH, THE MECHANISMS UNDERLYING THESE EFFECTS ARE ONLY NOW BEING ELUCIDATED. CRC DEVELOPS OVER MANY YEARS AND IS TYPICALLY CHARACTERISED BY AN ACCUMULATION OF MUTATIONS, WHICH MAY ARISE AS A CONSEQUENCE OF INHERITED POLYMORPHISMS IN KEY GENES, BUT MORE COMMONLY AS A RESULT OF SPONTANEOUSLY ARISING MUTATIONS AFFECTING GENES CONTROLLING CELL PROLIFERATION, DIFFERENTIATION, APOPTOSIS AND DNA REPAIR. EPIGENETIC CHANGES ARE OBSERVED THROUGHOUT THE PROGRESS FROM NORMAL MORPHOLOGY THROUGH FORMATION OF ADENOMA, AND THE SUBSEQUENT DEVELOPMENT OF CARCINOMA. THE REASONS WHY THIS ACCUMULATION OF LOSS OF HOMOEOSTATIC CONTROLS ARISES ARE UNCLEAR BUT CHRONIC INFLAMMATION HAS BEEN PROPOSED TO PLAY A CENTRAL ROLE. OBESITY IS ASSOCIATED WITH INCREASED PLASMA LEVELS OF CHEMOKINES AND ADIPOKINES CHARACTERISTIC OF CHRONIC SYSTEMIC INFLAMMATION, AND DIETARY FACTORS SUCH AS FISH OILS AND PHYTOCHEMICALS HAVE BEEN SHOWN TO HAVE ANTI-INFLAMMATORY PROPERTIES AS WELL AS MODULATING ESTABLISHED RISK FACTORS SUCH AS APOPTOSIS AND CELL PROLIFERATION. THERE IS ALSO SOME EVIDENCE THAT DIET CAN MODIFY EPIGENETIC CHANGES. THIS PAPER BRIEFLY REVIEWS THE CURRENT STATE OF KNOWLEDGE IN RELATION TO CRC DEVELOPMENT AND CONSIDERS EVIDENCE FOR POTENTIAL MECHANISMS BY WHICH DIET MAY MODIFY RISK. 2011 7 4425 45 MOLECULAR BASIS OF AGEING IN CHRONIC METABOLIC DISEASES. AIM: OVER THE LAST DECADES, THE SHIFT IN AGE DISTRIBUTION TOWARDS OLDER AGES AND THE PROGRESSIVE AGEING WHICH HAS OCCURRED IN MOST POPULATIONS HAVE BEEN PARALLELED BY A GLOBAL EPIDEMIC OF OBESITY AND ITS RELATED METABOLIC DISORDERS, PRIMARILY, TYPE 2 DIABETES (T2D). DYSFUNCTION OF THE ADIPOSE TISSUE (AT) IS WIDELY RECOGNIZED AS A SIGNIFICANT HALLMARK OF THE AGEING PROCESS THAT, IN TURN, RESULTS IN SYSTEMIC METABOLIC ALTERATIONS. THESE INCLUDE INSULIN RESISTANCE, ACCUMULATION OF ECTOPIC LIPIDS AND CHRONIC INFLAMMATION, WHICH ARE RESPONSIBLE FOR AN ELEVATED RISK OF OBESITY AND T2D ONSET ASSOCIATED TO AGEING. ON THE OTHER HAND, OBESITY AND T2D, THE PARADIGMS OF AT DYSFUNCTION, SHARE MANY PHYSIOLOGICAL CHARACTERISTICS WITH THE AGEING PROCESS, SUCH AS AN INCREASED BURDEN OF SENESCENT CELLS AND EPIGENETIC ALTERATIONS. THUS, THESE CHRONIC METABOLIC DISORDERS MAY REPRESENT A STATE OF ACCELERATED AGEING. MATERIALS AND METHODS: A MORE PRECISE EXPLANATION OF THE FUNDAMENTAL AGEING MECHANISMS THAT OCCUR IN AT AND A DEEPER UNDERSTANDING OF THEIR ROLE IN THE INTERPLAY BETWEEN ACCELERATED AGEING AND AT DYSFUNCTION CAN BE A FUNDAMENTAL LEAP TOWARDS NOVEL THERAPIES THAT ADDRESS THE CAUSES, NOT JUST THE SYMPTOMS, OF OBESITY AND T2D, UTILIZING STRATEGIES THAT TARGET EITHER SENESCENT CELLS OR DNA METHYLATION. RESULTS: IN THIS REVIEW, WE SUMMARIZE THE CURRENT KNOWLEDGE OF THE PATHWAYS THAT LEAD TO AT DYSFUNCTION IN THE CHRONOLOGICAL AGEING PROCESS AS WELL AS THE PATHOPHYSIOLOGY OF OBESITY AND T2D, EMPHASIZING THE CRITICAL ROLE OF CELLULAR SENESCENCE AND DNA METHYLATION. CONCLUSION: FINALLY, WE HIGHLIGHT THE NEED FOR FURTHER RESEARCH FOCUSED ON TARGETING THESE MECHANISMS. 2020 8 2163 33 EPIGENETIC MECHANISMS IN DIABETIC VASCULAR COMPLICATIONS. THERE HAS BEEN A RAPID INCREASE IN THE INCIDENCE OF DIABETES AS WELL THE ASSOCIATED VASCULAR COMPLICATIONS. BOTH GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN IMPLICATED IN THESE PATHOLOGIES. INCREASING EVIDENCE SUGGESTS THAT EPIGENETIC FACTORS PLAY A KEY ROLE IN THE COMPLEX INTERPLAY BETWEEN GENES AND THE ENVIRONMENT. ACTIONS OF MAJOR PATHOLOGICAL MEDIATORS OF DIABETES AND ITS COMPLICATIONS SUCH AS HYPERGLYCAEMIA, OXIDANT STRESS, AND INFLAMMATORY FACTORS CAN LEAD TO DYSREGULATED EPIGENETIC MECHANISMS THAT AFFECT CHROMATIN STRUCTURE AND GENE EXPRESSION. FURTHERMORE, PERSISTENCE OF THIS ALTERED STATE OF THE EPIGENOME MAY BE THE UNDERLYING MECHANISM CONTRIBUTING TO A 'METABOLIC MEMORY' THAT RESULTS IN CHRONIC INFLAMMATION AND VASCULAR DYSFUNCTION IN DIABETES EVEN AFTER ACHIEVING GLYCAEMIC CONTROL. FURTHER EXAMINATION OF EPIGENETIC MECHANISMS BY ALSO TAKING ADVANTAGE OF RECENTLY DEVELOPED NEXT-GENERATION SEQUENCING TECHNOLOGIES CAN PROVIDE NOVEL INSIGHTS INTO THE PATHOLOGY OF DIABETES AND ITS COMPLICATIONS AND LEAD TO THE DISCOVERY OF MUCH NEEDED NEW DRUG TARGETS FOR THESE DISEASES. IN THIS REVIEW, WE HIGHLIGHT THE ROLE OF EPIGENETICS IN DIABETES AND ITS VASCULAR COMPLICATIONS, AND RECENT TECHNOLOGICAL ADVANCES THAT HAVE SIGNIFICANTLY ACCELERATED THE FIELD. 2011 9 3748 37 INSIGHTS INTO THE ROLE OF DNA METHYLATION AND PROTEIN MISFOLDING IN DIABETES MELLITUS. BACKGROUND: DIABETES MELLITUS IS A METABOLIC DISORDER THAT IS CHARACTERIZED BY IMPAIRED GLUCOSE TOLERANCE RESULTING FROM DEFECTS IN INSULIN SECRETION, INSULIN ACTION, OR BOTH. EPIGENETIC MODIFICATIONS, WHICH ARE DEFINED AS INHERITED CHANGES IN GENE EXPRESSION THAT OCCUR WITHOUT CHANGES IN GENE SEQUENCE, ARE INVOLVED IN THE ETIOLOGY OF DIABETES. METHODS: IN THIS REVIEW, WE FOCUSED ON THE ROLE OF DNA METHYLATION AND PROTEIN MISFOLDING AND THEIR CONTRIBUTION TO THE DEVELOPMENT OF BOTH TYPE 1 AND TYPE 2 DIABETES MELLITUS. RESULTS: CHANGES IN DNA METHYLATION IN PARTICULAR ARE HIGHLY ASSOCIATED WITH THE DEVELOPMENT OF DIABETES. PROTEIN FUNCTION IS DEPENDENT ON THEIR PROPER FOLDING IN THE ENDOPLASMIC RETICULUM. DEFECTIVE PROTEIN FOLDING AND CONSEQUENTLY THEIR FUNCTIONS HAVE ALSO BEEN REPORTED TO PLAY A ROLE. EARLY TREATMENT OF DIABETES HAS PROVEN TO BE OF GREAT BENEFIT, AS EVEN TRANSIENT HYPERGLYCEMIA MAY LEAD TO PATHOLOGICAL EFFECTS AND COMPLICATIONS LATER ON. THIS HAS BEEN EXPLAINED BY THE THEORY OF THE DEVELOPMENT OF A METABOLIC MEMORY IN DIABETES. THE BASIS FOR THIS METABOLIC MEMORY WAS ATTRIBUTED TO OXIDATIVE STRESS, CHRONIC INFLAMMATION, NON-ENZYMATIC GLYCATION OF PROTEINS AND IMPORTANTLY, EPIGENETIC CHANGES. THIS HIGHLIGHTS THE IMPORTANCE OF LINKING NEW THERAPEUTICS TARGETING EPIGENETIC MECHANISMS WITH TRADITIONAL ANTIDIABETIC DRUGS. CONCLUSION: ALTHOUGH NEW DATA IS EVOLVING ON THE RELATION BETWEEN DNA METHYLATION, PROTEIN MISFOLDING, AND THE ETIOLOGY OF DIABETES, MORE STUDIES ARE REQUIRED FOR DEVELOPING NEW RELEVANT DIAGNOSTICS AND THERAPEUTICS. 2019 10 5821 39 STRESS IN OBESITY AND ASSOCIATED METABOLIC AND CARDIOVASCULAR DISORDERS. OBESITY HAS SIGNIFICANT IMPLICATIONS FOR HEALTHCARE, SINCE IT IS A MAJOR RISK FACTOR FOR BOTH TYPE 2 DIABETES AND THE METABOLIC SYNDROME. THIS SYNDROME IS A COMMON AND COMPLEX DISORDER COMBINING OBESITY, DYSLIPIDEMIA, HYPERTENSION, AND INSULIN RESISTANCE. IT IS ASSOCIATED WITH HIGH ATHEROSCLEROTIC CARDIOVASCULAR RISK, WHICH CAN ONLY PARTIALLY BE EXPLAINED BY ITS COMPONENTS. THEREFORE, TO EXPLAIN HOW OBESITY CONTRIBUTES TO THE DEVELOPMENT OF METABOLIC AND CARDIOVASCULAR DISORDERS, MORE AND BETTER INSIGHT IS REQUIRED INTO THE EFFECTS OF PERSONAL AND ENVIRONMENTAL STRESS ON DISEASE PROCESSES. IN THIS PAPER, WE SHOW THAT OBESITY IS A CHRONIC INFLAMMATORY DISEASE, WHICH HAS MANY MOLECULAR MECHANISMS IN COMMON WITH ATHEROSCLEROSIS. FURTHERMORE, WE FOCUS ON THE ROLE OF OXIDATIVE STRESS ASSOCIATED WITH OBESITY IN THE DEVELOPMENT OF THE METABOLIC SYNDROME. WE DISCUSS HOW SEVERAL STRESS CONDITIONS ARE RELATED TO INFLAMMATION AND OXIDATIVE STRESS IN ASSOCIATION WITH OBESITY AND ITS COMPLICATIONS. WE ALSO EMPHASIZE THE RELATION BETWEEN STRESS CONDITIONS AND THE DEREGULATION OF EPIGENETIC CONTROL MECHANISMS BY MEANS OF MICRORNAS AND SHOW HOW THIS IMPAIRMENT FURTHER CONTRIBUTES TO THE DEVELOPMENT OF OBESITY, CLOSING THE VICIOUS CIRCLE. FINALLY, WE DISCUSS THE LIMITATIONS OF CURRENT ANTI-INFLAMMATION AND ANTIOXIDANT THERAPY TO TREAT OBESITY. 2012 11 6287 41 THE POTENTIAL ROLE OF ENVIRONMENTAL FACTORS IN MODULATING MITOCHONDRIAL DNA EPIGENETIC MARKS. MANY STUDIES IMPLICATE MITOCHONDRIAL DYSFUNCTION IN THE DEVELOPMENT AND PROGRESSION OF NUMEROUS CHRONIC DISEASES. MITOCHONDRIA ARE RESPONSIBLE FOR MOST CELLULAR ENERGY PRODUCTION, AND UNLIKE OTHER CYTOPLASMIC ORGANELLES, MITOCHONDRIA CONTAIN THEIR OWN GENOME. MOST RESEARCH TO DATE, THROUGH INVESTIGATING MITOCHONDRIAL DNA COPY NUMBER, HAS FOCUSED ON LARGER STRUCTURAL CHANGES OR ALTERATIONS TO THE ENTIRE MITOCHONDRIAL GENOME AND THEIR ROLE IN HUMAN DISEASE. USING THESE METHODS, MITOCHONDRIAL DYSFUNCTION HAS BEEN LINKED TO CANCERS, CARDIOVASCULAR DISEASE, AND METABOLIC HEALTH. HOWEVER, LIKE THE NUCLEAR GENOME, THE MITOCHONDRIAL GENOME MAY EXPERIENCE EPIGENETIC ALTERATIONS, INCLUDING DNA METHYLATION THAT MAY PARTIALLY EXPLAIN SOME OF THE HEALTH EFFECTS OF VARIOUS EXPOSURES. RECENTLY, THERE HAS BEEN A MOVEMENT TO UNDERSTAND HUMAN HEALTH AND DISEASE WITHIN THE CONTEXT OF THE EXPOSOME, WHICH AIMS TO DESCRIBE AND QUANTIFY THE ENTIRETY OF ALL EXPOSURES PEOPLE ENCOUNTER THROUGHOUT THEIR LIVES. THESE INCLUDE, AMONG OTHERS, ENVIRONMENTAL POLLUTANTS, OCCUPATIONAL EXPOSURES, HEAVY METALS, AND LIFESTYLE AND BEHAVIORAL FACTORS. IN THIS CHAPTER, WE SUMMARIZE THE CURRENT RESEARCH ON MITOCHONDRIA AND HUMAN HEALTH, PROVIDE AN OVERVIEW OF THE CURRENT KNOWLEDGE ON MITOCHONDRIAL EPIGENETICS, AND DESCRIBE THE EXPERIMENTAL AND EPIDEMIOLOGIC STUDIES THAT HAVE INVESTIGATED PARTICULAR EXPOSURES AND THEIR RELATIONSHIPS WITH MITOCHONDRIAL EPIGENETIC MODIFICATIONS. WE CONCLUDE THE CHAPTER WITH SUGGESTIONS FOR FUTURE DIRECTIONS IN EPIDEMIOLOGIC AND EXPERIMENTAL RESEARCH THAT IS NEEDED TO ADVANCE THE GROWING FIELD OF MITOCHONDRIAL EPIGENETICS. 2023 12 6034 38 THE CHALLENGE BY MULTIPLE ENVIRONMENTAL AND BIOLOGICAL FACTORS INDUCE INFLAMMATION IN AGING: THEIR ROLE IN THE PROMOTION OF CHRONIC DISEASE. THE AGING PROCESS IS DRIVEN BY MULTIPLE MECHANISMS THAT LEAD TO CHANGES IN ENERGY PRODUCTION, OXIDATIVE STRESS, HOMEOSTATIC DYSREGULATION AND EVENTUALLY TO LOSS OF FUNCTIONALITY AND INCREASED DISEASE SUSCEPTIBILITY. MOST AGED INDIVIDUALS DEVELOP CHRONIC LOW-GRADE INFLAMMATION, WHICH IS AN IMPORTANT RISK FACTOR FOR MORBIDITY, PHYSICAL AND COGNITIVE IMPAIRMENT, FRAILTY, AND DEATH. AT ANY AGE, CHRONIC INFLAMMATORY DISEASES ARE MAJOR CAUSES OF MORBIMORTALITY, AFFECTING UP TO 5-8% OF THE POPULATION OF INDUSTRIALIZED COUNTRIES. SEVERAL ENVIRONMENTAL FACTORS CAN PLAY AN IMPORTANT ROLE FOR MODIFYING THE INFLAMMATORY STATE. GENETICS ACCOUNTS FOR ONLY A SMALL FRACTION OF CHRONIC-INFLAMMATORY DISEASES, WHEREAS ENVIRONMENTAL FACTORS APPEAR TO PARTICIPATE, EITHER WITH A CAUSATIVE OR A PROMOTIONAL ROLE IN 50% TO 75% OF PATIENTS. SEVERAL OF THOSE CHANGES DEPEND ON EPIGENETIC CHANGES THAT WILL FURTHER MODIFY THE INDIVIDUAL RESPONSE TO ADDITIONAL STIMULI. THE INTERACTION BETWEEN INFLAMMATION AND THE ENVIRONMENT OFFERS IMPORTANT INSIGHTS ON AGING AND HEALTH. THESE CONDITIONS, OFTEN DEPENDING ON THE INDIVIDUAL'S SEX, APPEAR TO LEAD TO DECREASED LONGEVITY AND PHYSICAL AND COGNITIVE DECLINE. IN ADDITION TO BIOLOGICAL FACTORS, THE ENVIRONMENT IS ALSO INVOLVED IN THE GENERATION OF PSYCHOLOGICAL AND SOCIAL CONTEXT LEADING TO STRESS. POOR PSYCHOLOGICAL ENVIRONMENTS AND OTHER SOURCES OF STRESS ALSO RESULT IN INCREASED INFLAMMATION. HOWEVER, THE MECHANISMS UNDERLYING THE ROLE OF ENVIRONMENTAL AND PSYCHOSOCIAL FACTORS AND NUTRITION ON THE REGULATION OF INFLAMMATION, AND HOW THE RESPONSE ELICITED FOR THOSE FACTORS INTERACT AMONG THEM, ARE POORLY UNDERSTOOD. WHEREAS CERTAIN DELETERIOUS ENVIRONMENTAL FACTORS RESULT IN THE GENERATION OF OXIDATIVE STRESS DRIVEN BY AN INCREASED PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES, ENDOPLASMIC RETICULUM STRESS, AND INFLAMMATION, OTHER FACTORS, INCLUDING NUTRITION (POLYUNSATURATED FATTY ACIDS) AND BEHAVIORAL FACTORS (EXERCISE) CONFER PROTECTION AGAINST INFLAMMATION, OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS, AND THUS AMELIORATE THEIR DELETERIOUS EFFECT. HERE, WE DISCUSS PROCESSES AND MECHANISMS OF INFLAMMATION ASSOCIATED WITH ENVIRONMENTAL FACTORS AND BEHAVIOR, THEIR LINKS TO SEX AND GENDER, AND THEIR OVERALL IMPACT ON AGING. 2020 13 4403 45 MODULATION OF THE INFLAMMATORY RESPONSE IN POLYCYSTIC OVARY SYNDROME (PCOS)-SEARCHING FOR EPIGENETIC FACTORS. POLYCYSTIC OVARY SYNDROME (PCOS) IS THE MOST COMMON ENDOCRINE DISORDER IN WOMEN OF REPRODUCTIVE AGE. DESPITE ITS INCIDENCE, THE SYNDROME IS POORLY UNDERSTOOD AND REMAINS UNDERDIAGNOSED, AND FEMALE PATIENTS ARE DIAGNOSED WITH A DELAY. THE HETEROGENOUS NATURE OF THIS COMPLEX DISORDER RESULTS FROM THE COMBINED OCCURRENCE OF GENETIC, ENVIRONMENTAL, ENDOCRINE, AND BEHAVIORAL FACTORS. PRIMARY CLINICAL MANIFESTATIONS OF PCOS ARE DERIVED FROM THE EXCESS OF ANDROGENS (ANOVULATION, POLYCYSTIC OVARY MORPHOLOGY, LACK OF OR SCANTY, IRREGULAR MENSTRUAL PERIODS, ACNE AND HIRSUTISM), WHEREAS THE SECONDARY MANIFESTATIONS INCLUDE MULTIPLE METABOLIC, CARDIOVASCULAR, AND PSYCHOLOGICAL DISORDERS. DIETARY AND LIFESTYLE FACTORS PLAY IMPORTANT ROLES IN THE DEVELOPMENT AND COURSE OF PCOS, WHICH SUGGESTS STRONG EPIGENETIC AND ENVIRONMENTAL INFLUENCES. MANY STUDIES HAVE SHOWN A STRONG ASSOCIATION BETWEEN PCOS AND CHRONIC, LOW-GRADE INFLAMMATION BOTH IN THE OVARIAN TISSUE AND THROUGHOUT THE BODY. IN THE VAST MAJORITY OF PCOS PATIENTS, ELEVATED VALUES OF INFLAMMATORY MARKERS OR THEIR GENE MARKERS HAVE BEEN REPORTED. DEVELOPMENT OF THE VICIOUS CYCLE OF THE CHRONIC INFLAMMATORY STATE IN PCOS IS ADDITIONALLY STIMULATED BY HYPERINSULINEMIA AND OBESITY. CHANGES IN DNA METHYLATION, HISTONE ACETYLATION AND NONCODING RNA LEVELS ARE PRESENTED IN THIS REVIEW IN THE CONTEXT OF OXIDATIVE STRESS, REACTIVE OXYGEN SPECIES, AND INFLAMMATORY SIGNALING IN PCOS. EPIGENETIC MODULATION OF ANDROGENIC ACTIVITY IN RESPONSE TO INFLAMMATORY SIGNALING IS ALSO DISCUSSED. 2022 14 1010 29 CHRONICALLY ELEVATED PROLIFERATION AS A RISK FACTOR FOR NEOPLASIA. CHRONIC DISEASE CONDITIONS THAT ARE ASSOCIATED WITH ELEVATED PROLIFERATION ARE WELL ESTABLISHED AS RISK FACTORS FOR CANCER DEVELOPMENT. THESE MAY BE DUE TO VIRUSES (FOR EXAMPLE, IN THE CASE OF HEPATITIS AND LIVER CANCER), BACTERIAL INFECTIONS, PARASITE INFESTATION OR PHYSICAL TRAUMA. IN ADDITION TO THESE EXOGENOUS AGENTS THERE ARE ALSO METABOLIC ABNORMALITIES THAT CAN CONTRIBUTE, CAUSED BY GENETIC OR EPIGENETIC INFLUENCE. IN THE LATTER CASE, AN INCREASE IN SERUM LEVELS OF THE HORMONES OESTROGEN, TESTOSTERONE AND INSULIN MAY BE OF SPECIAL IMPORTANCE. THE PRESENT REVIEW CONCENTRATES ATTENTION ON FACTORS THAT INDUCE ELEVATED CELL TURNOVER AND FOR WHICH THERE IS EPIDEMIOLOGICAL AND/OR EXPERIMENTAL EVIDENCE OF A LINK WITH NEOPLASIA, WITH PARTICULAR STRESS ON THE INDIVIDUAL ORGAN OR TISSUE LEVEL. 1998 15 6183 37 THE IMPACT OF ENVIRONMENTAL FACTORS IN INFLUENCING EPIGENETICS RELATED TO OXIDATIVE STATES IN THE CARDIOVASCULAR SYSTEM. OXIDATIVE STATES EXERT A SIGNIFICANT INFLUENCE ON A WIDE RANGE OF BIOLOGICAL AND MOLECULAR PROCESSES AND FUNCTIONS. WHEN THEIR BALANCE IS SHIFTED TOWARDS ENHANCED AMOUNTS OF FREE RADICALS, PATHOLOGICAL PHENOMENA CAN OCCUR, AS THE GENERATION OF REACTIVE OXYGEN SPECIES (ROS) IN TISSUE MICROENVIRONMENT OR IN THE SYSTEMIC CIRCULATION CAN BE DETRIMENTAL. EPIDEMIC CHRONIC DISEASES OF WESTERN SOCIETIES, SUCH AS CARDIOVASCULAR DISEASE, OBESITY, AND DIABETES CORRELATE WITH THE IMBALANCE OF REDOX HOMEOSTASIS. CURRENT ADVANCES IN OUR UNDERSTANDING OF EPIGENETICS HAVE REVEALED A PARALLEL SCENARIO SHOWING THE INFLUENCE OF OXIDATIVE STRESS AS A MAJOR REGULATOR OF EPIGENETIC GENE REGULATION VIA MODIFICATION OF DNA METHYLATION, HISTONES, AND MICRORNAS. THIS HAS PROVIDED BOTH THE BIOLOGICAL LINK AND A POTENTIAL MOLECULAR EXPLANATION BETWEEN OXIDATIVE STRESS AND CARDIOVASCULAR/METABOLIC PHENOMENA. ACCORDINGLY, IN THIS REVIEW, WE WILL PROVIDE CURRENT INSIGHTS ON THE PHYSIOLOGICAL AND PATHOLOGICAL IMPACT OF CHANGES IN OXIDATIVE STATES ON CARDIOVASCULAR DISORDERS, BY SPECIFICALLY FOCUSING ON THE INFLUENCE OF EPIGENETIC REGULATION. A SPECIAL EMPHASIS WILL HIGHLIGHT THE EFFECT ON EPIGENETIC REGULATION OF HUMAN'S CURRENT LIFE HABITS, EXTERNAL AND ENVIRONMENTAL FACTORS, INCLUDING FOOD INTAKE, TOBACCO, AIR POLLUTION, AND ANTIOXIDANT-BASED APPROACHES. ADDITIONALLY, THE STRATEGY TO QUANTIFY OXIDATIVE STATES IN HUMANS IN ORDER TO DETERMINE WHICH BIOLOGICAL MARKER COULD BEST MATCH A SUBJECT'S PROFILE WILL BE DISCUSSED. 2017 16 3404 32 HOW EPIGENETICS IMPACTS ON HUMAN DISEASES. EPIGENETICS IS A RAPIDLY GROWING FIELD OF BIOLOGY THAT STUDIES THE CHANGES IN GENE EXPRESSION THAT ARE NOT DUE TO ALTERATIONS IN THE DNA SEQUENCE BUT RATHER THE CHEMICAL MODIFICATIONS OF DNA AND ITS ASSOCIATED PROTEINS. EPIGENETIC MECHANISMS CAN PROFOUNDLY INFLUENCE GENE EXPRESSION, CELL DIFFERENTIATION, TISSUE DEVELOPMENT, AND DISEASE SUSCEPTIBILITY. UNDERSTANDING EPIGENETIC CHANGES IS ESSENTIAL TO ELUCIDATE THE MECHANISMS UNDERLYING THE INCREASINGLY RECOGNIZED ROLE OF ENVIRONMENTAL AND LIFESTYLE FACTORS IN HEALTH AND DISEASE AND THE INTERGENERATIONAL TRANSMISSION OF PHENOTYPES. RECENT STUDIES SUGGEST EPIGENETICS MAY BE CRITICAL IN VARIOUS DISEASES, FROM CARDIOVASCULAR DISEASE AND CANCER TO NEURODEVELOPMENTAL AND NEURODEGENERATIVE DISORDERS. EPIGENETIC MODIFICATIONS ARE POTENTIALLY REVERSIBLE AND COULD PROVIDE NEW THERAPEUTIC AVENUES FOR TREATING THESE DISEASES USING EPIGENETIC MODULATORS. MOREOVER, EPIGENETICS PROVIDE INSIGHT INTO DISEASE PATHOGENESIS AND BIOMARKERS FOR DISEASE DIAGNOSIS AND RISK STRATIFICATION. NEVERTHELESS, EPIGENETIC INTERVENTIONS HAVE THE POTENTIAL FOR UNINTENDED CONSEQUENCES AND MAY POTENTIALLY LEAD TO INCREASED RISKS OF UNEXPECTED OUTCOMES, SUCH AS ADVERSE DRUG REACTIONS, DEVELOPMENTAL ABNORMALITIES, AND CANCER. THEREFORE, RIGOROUS STUDIES ARE ESSENTIAL TO MINIMIZE THE RISKS ASSOCIATED WITH EPIGENETIC THERAPIES AND TO DEVELOP SAFE AND EFFECTIVE INTERVENTIONS FOR IMPROVING HUMAN HEALTH. THIS ARTICLE PROVIDES A SYNTHETIC AND HISTORICAL VIEW OF THE ORIGIN OF EPIGENETICS AND SOME OF THE MOST RELEVANT ACHIEVEMENTS. 2023 17 1112 39 COMMON PATHOGENETIC MECHANISMS UNDERLYING AGING AND TUMOR AND MEANS OF INTERVENTIONS. RECENTLY, THERE HAS BEEN AN INCREASE IN THE INCIDENCE OF MALIGNANT TUMORS AMONG THE OLDER POPULATION. MOREOVER, THERE IS AN ASSOCIATION BETWEEN AGING AND CANCER. DURING THE PROCESS OF SENESCENCE, THE HUMAN BODY SUFFERS FROM A SERIES OF IMBALANCES, WHICH HAVE BEEN SHOWN TO FURTHER ACCELERATE AGING, TRIGGER TUMORIGENESIS, AND FACILITATE CANCER PROGRESSION. THEREFORE, EXPLORING THE JUNCTIONS OF AGING AND CANCER AND SEARCHING FOR NOVEL METHODS TO RESTORE THE JUNCTIONS IS OF GREAT IMPORTANCE TO INTERVENE AGAINST AGING-RELATED CANCERS. IN THIS REVIEW, WE HAVE IDENTIFIED THE UNDERLYING PATHOGENETIC MECHANISMS OF AGING-RELATED CANCERS BY COMPARING ALTERATIONS IN THE HUMAN BODY CAUSED BY AGING AND THE FACTORS THAT TRIGGER CANCERS. WE FOUND THAT THE COMMON MECHANISMS OF AGING AND CANCER INCLUDE CELLULAR SENESCENCE, ALTERATIONS IN PROTEOSTASIS, MICROBIOTA DISORDERS (DECREASED PROBIOTICS AND INCREASED PERNICIOUS BACTERIA), PERSISTENT CHRONIC INFLAMMATION, EXTENSIVE IMMUNOSENESCENCE, INORDINATE ENERGY METABOLISM, ALTERED MATERIAL METABOLISM, ENDOCRINE DISORDERS, ALTERED GENETIC EXPRESSION, AND EPIGENETIC MODIFICATION. FURTHERMORE, WE HAVE PROPOSED THAT AGING AND CANCER HAVE COMMON MEANS OF INTERVENTION, INCLUDING NOVEL USES OF COMMON MEDICINE (METFORMIN, RESVERATROL, AND RAPAMYCIN), DIETARY RESTRICTION, AND ARTIFICIAL MICROBIOTA INTERVENTION OR SELECTIVELY REPLENISHING SCARCE METABOLITES. IN ADDITION, WE HAVE SUMMARIZED THE RESEARCH PROGRESS OF EACH INTERVENTION AND REVEALED THEIR BIDIRECTIONAL EFFECTS ON CANCER PROGRESSION TO COMPARE THEIR RELIABILITY AND FEASIBILITY. THEREFORE, THE STUDY FINDINGS PROVIDE VITAL INFORMATION FOR ADVANCED RESEARCH STUDIES ON AGE-RELATED CANCERS. HOWEVER, THERE IS A NEED FOR FURTHER OPTIMIZATION OF THE DESCRIBED METHODS AND MORE SUITABLE METHODS FOR COMPLICATED CLINICAL PRACTICES. IN CONCLUSION, TARGETING AGING MAY HAVE POTENTIAL THERAPEUTIC EFFECTS ON AGING-RELATED CANCERS. 2022 18 1871 35 EMERGING ROLE OF EPIGENETICS IN EXPLAINING RELATIONSHIP OF PERIODONTITIS AND CARDIOVASCULAR DISEASES. CARDIOVASCULAR DISEASES SUCH AS ISCHEMIC HEART DISEASES OR STROKE ARE AMONG THE LEADING CAUSE OF DEATHS GLOBALLY, AND EVIDENCE SUGGESTS THAT THESE DISEASES ARE MODULATED BY A MULTIFACTORIAL AND COMPLEX INTERPLAY OF GENETIC, ENVIRONMENTAL, AND LIFESTYLE FACTORS. GENETIC PREDISPOSITION AND CHRONIC EXPOSURE TO MODIFIABLE RISK FACTORS HAVE BEEN EXPLORED TO BE INVOLVED IN THE PATHOPHYSIOLOGY OF CVD. ENVIRONMENTAL FACTORS CONTRIBUTE TO AN INDIVIDUAL'S PROPENSITY TO DEVELOP MAJOR CARDIOVASCULAR RISK FACTORS THROUGH EPIGENETIC MODIFICATIONS OF DNA AND HISTONES VIA MIRNA REGULATION OF PROTEIN TRANSLATION THAT ARE TYPES OF EPIGENETIC MECHANISMS AND PARTICIPATE IN DISEASE DEVELOPMENT. PERIODONTAL DISEASE (PD) IS ONE OF THE MOST COMMON ORAL DISEASES IN HUMANS THAT IS CHARACTERIZED BY LOW-GRADE INFLAMMATION AND HAS BEEN SHOWN TO INCREASE THE RISK OF CVDS. RISK FACTORS INVOLVED IN PD AND CVD ARE DETERMINED BOTH GENETICALLY AND BEHAVIORALLY. PERIODONTAL DISEASES SUCH AS CHRONIC INFLAMMATION PROMOTE DNA METHYLATION. EPIGENETIC MODIFICATIONS INVOLVED IN THE INITIATION AND PROGRESSION OF ATHEROSCLEROSIS PLAY AN ESSENTIAL ROLE IN PLAQUE DEVELOPMENT AND VULNERABILITY. EPIGENETICS HAS OPENED A NEW WORLD TO UNDERSTAND AND MANAGE HUMAN DISEASES, INCLUDING CVDS AND PERIODONTAL DISEASES. GENETIC MEDICINE HAS STARTED A NEW ERA OF EPIGENETICS TO OVERCOME HUMAN DISEASES WITH VARIOUS NEW METHODOLOGY. EPIGENETIC PROFILING MAY AID IN BETTER DIAGNOSIS AND STRATIFICATION OF PATIENTS SHOWING POTENTIAL PREDISPOSED STATES FOR DISEASE. A BETTER UNDERSTANDING OF THE EXACT REGULATORY MECHANISMS OF EPIGENETIC PATHWAYS DRIVING INFLAMMATION IS SLOWLY EMERGING AND WILL AID IN DEVELOPING NOVEL TOOLS FOR THE TREATMENT OF DISEASE. 2021 19 5105 42 POLYCYSTIC OVARIAN SYNDROME: A COMPLEX DISEASE WITH A GENETICS APPROACH. POLYCYSTIC OVARIAN SYNDROME (PCOS) IS A COMPLEX ENDOCRINE DISORDER AFFECTING FEMALES IN THEIR REPRODUCTIVE AGE. THE EARLY DIAGNOSIS OF PCOS IS COMPLICATED AND COMPLEX DUE TO OVERLAPPING SYMPTOMS OF THIS DISEASE. THE MOST ACCEPTED DIAGNOSTIC APPROACH TODAY IS THE ROTTERDAM CONSENSUS (2003), WHICH SUPPORTS THE POSITIVE DIAGNOSIS OF PCOS WHEN PATIENTS PRESENT TWO OUT OF THE FOLLOWING THREE SYMPTOMS: BIOCHEMICAL AND CLINICAL SIGNS OF HYPERANDROGENISM, OLIGO, AND ANOVULATION, ALSO POLYCYSTIC OVARIAN MORPHOLOGY ON SONOGRAPHY. GENETIC VARIANCE, EPIGENETIC CHANGES, AND DISTURBED LIFESTYLE LEAD TO THE DEVELOPMENT OF PATHOPHYSIOLOGICAL DISTURBANCES, WHICH INCLUDE HYPERANDROGENISM, INSULIN RESISTANCE, AND CHRONIC INFLAMMATION IN PCOS FEMALES. AT THE MOLECULAR LEVEL, DIFFERENT PROTEINS AND MOLECULAR AND SIGNALING PATHWAYS ARE INVOLVED IN DISEASE PROGRESSION, WHICH LEADS TO THE FAILURE OF A SINGLE GENETIC DIAGNOSTIC APPROACH. THE GENETIC APPROACH TO ELUCIDATE THE MECHANISM OF PATHOGENESIS OF PCOS WAS RECENTLY DEVELOPED, WHEREBY FOUR PHENOTYPIC VARIANCES OF PCOS CATEGORIZE PCOS PATIENTS INTO CLASSIC, OVULATORY, AND NON-HYPERANDROGENIC TYPES. GENETIC STUDIES HELP TO IDENTIFY THE ROOT CAUSE FOR THE DEVELOPMENT OF THIS PCOS. PCOS GENETIC INHERITANCE IS AUTOSOMAL DOMINANT BUT THE LATEST INVESTIGATIONS REVEALED IT AS A MULTIGENE ORIGIN DISEASE. DIFFERENT GENETIC LOCI AND SPECIFIC GENES HAVE BEEN IDENTIFIED SO FAR AS BEING ASSOCIATED WITH THIS DISEASE. GENOME-WIDE ASSOCIATION STUDIES (GWAS) AND RELATED GENETIC STUDIES HAVE CHANGED THE SCENARIO FOR THE DIAGNOSIS AND TREATMENT OF THIS REPRODUCTIVE AND METABOLIC CONDITION KNOWN AS PCOS. THIS REVIEW ARTICLE BRIEFLY DISCUSSES DIFFERENT GENES ASSOCIATED DIRECTLY OR INDIRECTLY WITH DISEASE DEVELOPMENT AND PROGRESSION. 2022 20 738 33 CANCER SUSCEPTIBILITY: EPIGENETIC MANIFESTATION OF ENVIRONMENTAL EXPOSURES. CANCER IS A DISEASE THAT RESULTS FROM BOTH GENETIC AND EPIGENETIC CHANGES. DISCORDANT PHENOTYPES AND VARYING INCIDENCES OF COMPLEX DISEASES SUCH AS CANCER IN MONOZYGOTIC TWINS AS WELL AS GENETICALLY IDENTICAL LABORATORY ANIMALS HAVE LONG BEEN ATTRIBUTED TO DIFFERENCES IN ENVIRONMENTAL EXPOSURES. ACCUMULATING EVIDENCE INDICATES, HOWEVER, THAT DISPARITIES IN GENE EXPRESSION RESULTING FROM VARIABLE MODIFICATIONS IN DNA METHYLATION AND CHROMATIN STRUCTURE IN RESPONSE TO THE ENVIRONMENT ALSO PLAY A ROLE IN DIFFERENTIAL SUSCEPTIBILITY TO DISEASE. DESPITE A GROWING CONSENSUS ON THE IMPORTANCE OF EPIGENETICS IN THE ETIOLOGY OF CHRONIC HUMAN DISEASES, THE GENES MOST PRONE TO EPIGENETIC DYSREGULATION ARE INCOMPLETELY DEFINED. MOREOVER, NEITHER THE ENVIRONMENTAL AGENTS MOST STRONGLY AFFECTING THE EPIGENOME NOR THE CRITICAL WINDOWS OF VULNERABILITY TO ENVIRONMENTALLY INDUCED EPIGENETIC ALTERATIONS ARE ADEQUATELY CHARACTERIZED. THESE MAJOR DEFICITS IN KNOWLEDGE MARKEDLY IMPAIR OUR ABILITY TO UNDERSTAND FULLY THE ETIOLOGY OF CANCER AND THE IMPORTANCE OF THE EPIGENOME IN DIAGNOSING AND PREVENTING THIS DEVASTATING DISEASE. 2007