1 1889 93 ENDOMETRIOSIS MALIGNANT TRANSFORMATION: EPIGENETICS AS A PROBABLE MECHANISM IN OVARIAN TUMORIGENESIS. ENDOMETRIOSIS, DEFINED AS THE PRESENCE OF ECTOPIC ENDOMETRIAL GLANDS AND STROMA OUTSIDE THE UTERINE CAVITY, IS A CHRONIC, HORMONE-DEPENDENT GYNECOLOGIC DISEASE AFFECTING MILLIONS OF WOMEN ACROSS THE WORLD, WITH SYMPTOMS INCLUDING CHRONIC PELVIC PAIN, DYSMENORRHEA, DYSPAREUNIA, DYSURIA, AND SUBFERTILITY. IN ADDITION, THERE IS WELL-ESTABLISHED EVIDENCE THAT, ALTHOUGH ENDOMETRIOSIS IS CONSIDERED BENIGN, IT IS ASSOCIATED WITH AN INCREASED RISK OF MALIGNANT TRANSFORMATION, WITH THE INVOLVEMENT OF VARIOUS MECHANISMS OF DEVELOPMENT. MORE AND MORE EVIDENCE REVEALS AN IMPORTANT CONTRIBUTION OF EPIGENETIC MODIFICATION NOT ONLY IN ENDOMETRIOSIS BUT ALSO IN MECHANISMS OF ENDOMETRIOSIS MALIGNANT TRANSFORMATION, INCLUDING DNA METHYLATION AND DEMETHYLATION, HISTONE MODIFICATIONS, AND MIRNA ABERRANT EXPRESSIONS. IN THIS PRESENT REVIEW, WE MAINLY SUMMARIZE THE RESEARCH PROGRESS ABOUT THE CURRENT KNOWLEDGE REGARDING THE EPIGENETIC MODIFICATIONS OF THE RELATIONS BETWEEN ENDOMETRIOSIS MALIGNANT TRANSFORMATION AND OVARIAN CANCER IN AN EFFORT TO IDENTIFY SOME RISK FACTORS PROBABLY ASSOCIATED WITH ECTOPIC ENDOMETRIUM TRANSFORMATION. 2018 2 3820 24 INTRODUCTION TO PRECLINICAL EVIDENCE FROM ANIMAL MODELS OF ENDOMETRIOSIS. ENDOMETRIOSIS, THE PRESENCE AND GROWTH OF UTERINE ENDOMETRIAL GLANDULAR EPITHELIAL AND STROMA CELLS OUTSIDE THE UTERINE CAVITY, CAUSES PAIN AND INFERTILITY IN WOMEN AND GIRLS OF REPRODUCTIVE AGE. AS RANDOMIZED, DOUBLE-BLINDED, CONTROLLED STUDIES OF ENDOMETRIOSIS IN WOMEN ARE IMPRACTICAL AND AT TIMES ETHICALLY PROHIBITIVE, ANIMAL MODELS FOR ENDOMETRIOSIS AROSE AS AN IMPORTANT ADJUNCT TO GAIN MECHANISTIC INSIGHTS INTO THE ETIOLOGY AND PATHOPHYSIOLOGICAL MECHANISMS OF THIS PERPLEXING DISORDER. A MORE THOROUGH UNDERSTANDING OF ENDOMETRIOSIS IN WOMEN MAY HELP DEVELOP NOVEL NONINVASIVE DIAGNOSTICS, CLASSIFICATION SYSTEMS, THERAPEUTIC REGIMES, AND EVEN PREVENTATIVE METHODS FOR THE MANAGEMENT OF ENDOMETRIOSIS. THIS CHAPTER IS INTENDED TO INTRODUCE A BRIEF HISTORICAL BACKGROUND, BIOLOGICAL AND EPIDEMIOLOGICAL ASPECTS, THE MAJOR SYMPTOMS, THE EFFECTS OF ENDOCRINE-DISRUPTING CHEMICALS, AND AN EXAMPLE OF AN EPIGENETIC FACTOR OF ENDOMETRIOSIS IN WOMEN. 2020 3 1447 29 DIOXIN AND ENDOMETRIOSIS: A NEW POSSIBLE RELATION BASED ON EPIGENETIC THEORY. ENDOMETRIOSIS IS A CHRONIC DISEASE CHARACTERIZED BY THE GROWTH OF ENDOMETRIAL-LIKE GLANDS AND STROMA OUTSIDE THE UTERINE CAVITY. NOWADAYS, THE EXACT ETIOLOGY OF ENDOMETRIOSIS IS UNCLEAR AND THE INTERACTION BETWEEN A VARIETY OF ENVIRONMENTAL PHYSICAL AND CHEMICAL COMPOUNDS MAY POTENTIALLY PROMOTE THE DISEASE IN WOMEN WITH AN INDIVIDUAL SUSCEPTIBILITY. THE FIRST DEMONSTRATION OF A RELATION BETWEEN AN ENVIRONMENTAL FACTOR AND ENDOMETRIOSIS WAS OBTAINED WITH THE CHRONIC DIETARY EXPOSURE OF A PRIMATE COLONY TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD). BESIDES THE WELL-KNOWN DIOXIN'S PATHWAY OF ACTION, SEVERAL PAPERS ARE FOCUSING ON THE ROLE OF EPIGENETIC MECHANISMS, A WAY THROUGH WHICH THE GENOME RESPONDS TO THE ENVIRONMENT AND CAN LEAD TO PERMANENT CHANGES IN GENE EXPRESSION UNTIL AFFECTING THE PHENOTYPES OR CAUSE DISEASE. IN THIS REVIEW, WE FOCUS ON THE POSSIBLE ROLE OF DIOXIN EPIGENETICS MODIFICATION IN ENDOMETRIOSIS. 2020 4 2602 45 EPIGENETICS, ENDOMETRIOSIS AND SEX STEROID RECEPTORS: AN UPDATE ON THE EPIGENETIC REGULATORY MECHANISMS OF ESTROGEN AND PROGESTERONE RECEPTORS IN PATIENTS WITH ENDOMETRIOSIS. ENDOMETRIOSIS IS A BENIGN GYNECOLOGICAL DISEASE AFFECTING APPROXIMATELY 10% OF REPRODUCTIVE-AGED WOMEN AND IS DEFINED AS THE PRESENCE OF ENDOMETRIAL GLANDS AND STROMA OUTSIDE THE UTERINE CAVITY. ENDOMETRIOSIS CAN CAUSE A VARIETY OF HEALTH PROBLEMS, FROM PELVIC DISCOMFORT TO CATAMENIAL PNEUMOTHORAX, BUT IT'S MAINLY LINKED WITH SEVERE AND CHRONIC PELVIC PAIN, DYSMENORRHEA, AND DEEP DYSPAREUNIA, AS WELL AS REPRODUCTIVE ISSUES. THE PATHOGENESIS OF ENDOMETRIOSIS INVOLVES AN ENDOCRINE DYSFUNCTION, WITH ESTROGEN DEPENDENCY AND PROGESTERONE RESISTANCE, AND INFLAMMATORY MECHANISM ACTIVATION, TOGETHER WITH IMPAIRED CELL PROLIFERATION AND NEUROANGIOGENESIS. THE PRESENT CHAPTER AIMS TO DISCUSS THE MAIN EPIGENETIC MECHANISMS RELATED TO ESTROGEN RECEPTORS (ERS) AND PROGESTERONE RECEPTORS (PRS) IN PATIENTS WITH ENDOMETRIOSIS. THERE ARE NUMEROUS EPIGENETIC MECHANISMS PARTICIPATING IN ENDOMETRIOSIS, REGULATING THE EXPRESSION OF THE GENES ENCODING THESE RECEPTORS BOTH INDIRECTLY, THROUGH THE REGULATION OF TRANSCRIPTION FACTORS, AND DIRECTLY, THROUGH DNA METHYLATION, HISTONE MODIFICATIONS, MICRO RNAS AND LONG NONCODING RNAS. THIS REPRESENTS AN OPEN FIELD OF INVESTIGATION, WHICH MAY LEAD TO IMPORTANT CLINICAL IMPLICATIONS SUCH AS THE DEVELOPMENT OF EPIGENETIC DRUGS FOR THE TREATMENT OF ENDOMETRIOSIS AND THE IDENTIFICATION OF SPECIFIC AND EARLY BIOMARKERS FOR THE DISEASE. 2023 5 1114 32 COMMONALITIES AND DISPARITIES BETWEEN ENDOMETRIOSIS AND CHRONIC ENDOMETRITIS: THERAPEUTIC POTENTIAL OF NOVEL ANTIBIOTIC TREATMENT STRATEGY AGAINST ECTOPIC ENDOMETRIUM. CHRONIC ENDOMETRITIS (CE) IS A LOCAL MUCOSAL INFLAMMATORY DISORDER OF THE UTERINE LINING, WHICH IS HISTOPATHOLOGICALLY RECOGNIZED AS THE UNUSUAL INFILTRATION OF CD138(+) PLASMACYTES INTO THE ENDOMETRIAL STROMAL COMPARTMENT. ACCUMULATING BODY OF RESEARCH DOCUMENTED THAT CE IS ASSOCIATED WITH FEMALE INFERTILITY AND SEVERAL OBSTETRIC/NEONATAL COMPLICATIONS. THE MAJOR CAUSE OF CE IS THOUGHT TO BE INTRAUTERINE INFECTION REPRESENTED BY COMMON BACTERIA (ESCHERICHIA COLI, ENTEROCOCCUS FAECALIS, STREPTOCOCCUS, AND STAPHYLOCOCCUS), MYCOPLASMA/UREAPLASMA, AND MYCOBACTERIUM. ADDITIONALLY, LOCAL DYSBIOSIS IN THE FEMALE REPRODUCTIVE TRACT MAY BE INVOLVED IN THE ONSET AND DEVELOPMENT OF CE. ANTIBIOTIC TREATMENTS AGAINST THESE MICROORGANISMS ARE EFFECTIVE IN THE ELIMINATION OF ENDOMETRIAL STROMAL PLASMACYTES IN THE AFFECTED PATIENTS. MEANWHILE, ENDOMETRIOSIS IS A COMMON FEMALE REPRODUCTIVE TRACT DISEASE CHARACTERIZED BY ENDOMETRIOTIC TISSUES (ECTOPIC ENDOMETRIUM) GROWING OUTSIDE THE UTERUS AND POTENTIALLY CAUSES CHRONIC PELVIC SYMPTOMS (DYSMENORRHEA, DYSPAREUNIA, DYSCHEZIA, AND DYSURIA), INFERTILITY, AND OVARIAN CANCERS. ENDOMETRIOSIS INVOLVES ENDOCRINOLOGICAL, GENETIC, AND EPIGENETIC FACTORS IN ITS ETIOLOGY AND PATHOGENESIS. RECENT STUDIES FOCUS ON IMMUNOLOGICAL, INFLAMMATORY, AND INFECTIOUS ASPECTS OF ENDOMETRIOSIS AND DEMONSTRATE SEVERAL COMMON CHARACTERISTICS BETWEEN ENDOMETRIOSIS AND CE. THIS REVIEW AIMED TO BETTER UNDERSTAND THE IMMUNOLOGICAL AND MICROBIAL BACKGROUNDS UNDERLYING ENDOMETRIOSIS AND CE AND LOOK INTO THE THERAPEUTIC POTENTIAL OF THE NOVEL ANTIBIOTIC TREATMENT STRATEGY AGAINST ENDOMETRIOSIS IN LIGHT OF ENDOMETRIAL INFECTIOUS DISEASE. 2023 6 2669 33 ESTROGEN- AND PROGESTERONE (P4)-MEDIATED EPIGENETIC MODIFICATIONS OF ENDOMETRIAL STROMAL CELLS (ENSCS) AND/OR MESENCHYMAL STEM/STROMAL CELLS (MSCS) IN THE ETIOPATHOGENESIS OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A COMMON CHRONIC INFLAMMATORY CONDITION IN WHICH ENDOMETRIAL TISSUE APPEARS OUTSIDE THE UTERINE CAVITY. BECAUSE ECTOPIC ENDOMETRIOSIS CELLS EXPRESS BOTH ESTROGEN AND PROGESTERONE (P4) RECEPTORS, THEY GROW AND UNDERGO CYCLIC PROLIFERATION AND BREAKDOWN SIMILAR TO THE ENDOMETRIUM. THIS DEBILITATING GYNECOLOGICAL DISEASE AFFECTS UP TO 15% OF REPRODUCTIVE AGED WOMEN. DESPITE MANY YEARS OF RESEARCH, THE ETIOPATHOGENESIS OF ENDOMETRIAL LESIONS REMAINS UNCLEAR. RETROGRADE TRANSPORT OF THE VIABLE MENSTRUAL ENDOMETRIAL CELLS WITH RETAINED ABILITY FOR ATTACHMENT WITHIN THE PELVIC CAVITY, PROLIFERATION, DIFFERENTIATION AND SUBSEQUENT INVASION INTO THE SURROUNDING TISSUE CONSTITUTES THE RATIONALE FOR WIDELY ACCEPTED IMPLANTATION THEORY. ACCORDINGLY, THE MOST ABUNDANT CELLS IN THE ENDOMETRIUM ARE ENDOMETRIAL STROMAL CELLS (ENSCS). THESE CELLS CONSTITUTE A PARTICULAR POPULATION WITH CLONOGENIC ACTIVITY THAT RESEMBLES PROPERTIES OF MESENCHYMAL STEM/STROMAL CELLS (MSCS). THUS, A SIGNIFICANT ROLE OF STEM CELL-BASED DYSFUNCTION IN FORMATION OF THE INITIAL ENDOMETRIAL LESIONS IS SUSPECTED. THERE IS INCREASING EVIDENCE THAT THE ROLE OF EPIGENETIC MECHANISMS AND PROCESSES IN ENDOMETRIOSIS HAVE BEEN UNDERESTIMATED. THE IMPORTANCE OF EXCESS ESTROGEN EXPOSURE AND P4 RESISTANCE IN EPIGENETIC HOMEOSTASIS FAILURE IN THE ENDOMETRIAL/ENDOMETRIOTIC TISSUE ARE CRUCIAL. EPIGENETIC ALTERATIONS REGARDING TRANSCRIPTION FACTORS OF ESTROGEN AND P4 SIGNALING PATHWAYS IN MSCS ARE ROBUST IN ENDOMETRIOTIC TISSUE. THUS, PERSPECTIVES FOR THE FUTURE MAY INCLUDE MSCS AND ENSCS AS THE TARGETS OF EPIGENETIC THERAPIES IN THE PREVENTION AND TREATMENT OF ENDOMETRIOSIS. HERE, WE REVIEWED THE CURRENT KNOWN CHANGES IN THE EPIGENETIC BACKGROUND OF ENSCS AND MSCS DUE TO ESTROGEN/P4 IMBALANCES IN THE CONTEXT OF ETIOPATHOGENESIS OF ENDOMETRIOSIS. GRAPHICAL ABSTRACT. 2021 7 2275 42 EPIGENETIC REGULATION AND T-CELL RESPONSES IN ENDOMETRIOSIS - SOMETHING OTHER THAN AUTOIMMUNITY. ENDOMETRIOSIS IS DEFINED AS THE PRESENCE OF ENDOMETRIAL-LIKE GLANDS AND STROMA LOCATED OUTSIDE THE UTERINE CAVITY. THIS COMMON, ESTROGEN DEPENDENT, INFLAMMATORY CONDITION AFFECTS UP TO 15% OF REPRODUCTIVE-AGED WOMEN AND IS A WELL-RECOGNIZED CAUSE OF CHRONIC PELVIC PAIN AND INFERTILITY. DESPITE THE STILL UNKNOWN ETIOLOGY OF ENDOMETRIOSIS, MUCH EVIDENCE SUGGESTS THE PARTICIPATION OF EPIGENETIC MECHANISMS IN THE DISEASE ETIOPATHOGENESIS. THE MAIN RATIONALE IS BASED ON THE FACT THAT HERITABLE PHENOTYPE CHANGES THAT DO NOT INVOLVE ALTERATIONS IN THE DNA SEQUENCE ARE COMMON TRIGGERS FOR HORMONAL, IMMUNOLOGICAL, AND INFLAMMATORY DISORDERS, WHICH PLAY A KEY ROLE IN THE FORMATION OF ENDOMETRIOTIC FOCI. EPIGENETIC MECHANISMS REGULATING T-CELL RESPONSES, INCLUDING DNA METHYLATION AND POSTTRANSLATIONAL HISTONE MODIFICATIONS, DESERVE ATTENTION BECAUSE TISSUE-RESIDENT T LYMPHOCYTES WORK IN CONCERT WITH ORGAN STRUCTURAL CELLS TO GENERATE APPROPRIATE IMMUNE RESPONSES AND ARE FUNCTIONALLY SHAPED BY ORGAN-SPECIFIC ENVIRONMENTAL CONDITIONS. THUS, A FAILURE TO PRECISELY REGULATE IMMUNE CELL TRANSCRIPTION MAY RESULT IN COMPROMISED IMMUNOLOGICAL INTEGRITY OF THE ORGAN WITH AN INCREASED RISK OF INFLAMMATORY DISORDERS. THE COEXISTENCE OF ENDOMETRIOSIS AND AUTOIMMUNITY IS A WELL-KNOWN OCCURRENCE. RECENT RESEARCH RESULTS INDICATE REGULATORY T-CELL (TREG) ALTERATIONS IN ENDOMETRIOSIS, AND AN INCREASED NUMBER OF HIGHLY ACTIVE TREGS AND MACROPHAGES HAVE BEEN FOUND IN PERITONEAL FLUID FROM WOMEN WITH ENDOMETRIOSIS. ELIMINATION OF THE REGULATORY FUNCTION OF T CELLS AND AN IMBALANCE BETWEEN T HELPER CELLS OF THE TH1 AND TH2 TYPES HAVE BEEN REPORTED IN THE ENDOMETRIA OF WOMEN WITH ENDOMETRIOSIS-ASSOCIATED INFERTILITY. THIS REVIEW AIMS TO PRESENT THE STATE OF THE ART IN RECOGNITION EPIGENETIC REPROGRAMMING OF T CELLS AS THE KEY FACTOR IN THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS IN THE CONTEXT OF T-CELL-RELATED AUTOIMMUNITY. THE NEW POTENTIAL THERAPEUTIC APPROACHES BASED ON EPIGENETIC MODULATION AND/OR ADOPTIVE TRANSFER OF T CELLS WILL ALSO BE OUTLINED. 2022 8 6272 21 THE ORIGIN AND PATHOGENESIS OF ENDOMETRIOSIS. RECENT MOLECULAR GENETIC FINDINGS ON ENDOMETRIOSIS AND NORMAL ENDOMETRIUM SUGGEST A MODIFIED MODEL IN WHICH CIRCULATING EPITHELIAL PROGENITOR OR STEM CELLS INTENDED TO REGENERATE UTERINE ENDOMETRIUM AFTER MENSTRUATION MAY BECOME OVERREACTIVE AND TRAPPED OUTSIDE THE UTERUS. THESE TRAPPED EPITHELIUM-COMMITTED PROGENITOR CELLS FORM NASCENT GLANDS THROUGH CLONAL EXPANSION AND RECRUIT POLYCLONAL STROMAL CELLS, LEADING TO THE ESTABLISHMENT OF DEEP INFILTRATING ENDOMETRIOSIS. ONCE FORMED, THE ECTOPIC TISSUE BECOMES SUBJECT TO IMMUNE SURVEILLANCE, RESULTING IN CHRONIC INFLAMMATION. THE INFLAMMATORY RESPONSE ORCHESTRATED BY NUCLEAR FACTOR-KAPPAB SIGNALING IS EXACERBATED BY ABERRATIONS IN THE ESTROGEN RECEPTOR-BETA AND PROGESTERONE RECEPTOR PATHWAYS, WHICH ARE ALSO AFFECTED BY LOCAL INFLAMMATION, FORMING A DYSREGULATED INFLAMMATION-HORMONAL LOOP. GLANDULAR EPITHELIUM WITHIN ENDOMETRIOTIC TISSUE HARBORS CANCER-ASSOCIATED MUTATIONS THAT ARE FREQUENTLY DETECTED IN ENDOMETRIOSIS-RELATED OVARIAN CANCERS. IN THIS REVIEW, WE SUMMARIZE RECENT ADVANCES THAT HAVE ILLUMINATED THE ORIGIN AND PATHOGENESIS OF ENDOMETRIOSIS AND HAVE PROVIDED NEW AVENUES FOR RESEARCH THAT PROMISE TO IMPROVE THE EARLY DIAGNOSIS AND MANAGEMENT OF ENDOMETRIOSIS. 2020 9 4956 31 PATHOGENESIS OF ENDOMETRIOSIS: FOCUS ON ADENOGENESIS-RELATED FACTORS. ENDOMETRIOSIS CAN BE DEFINED AS THE PRESENCE OF THE ENDOMETRIUM OUTSIDE THE UTERINE CAVITY. IT AFFECTS APPROXIMATELY 10% OF WOMEN OF REPRODUCTIVE AGE AND CAUSES INFERTILITY, CHRONIC PAIN, AND DETERIORATION OF THE QUALITY OF LIFE. SINCE THE IDENTIFICATION OF THE DISEASE, VARIOUS PATHOGENETIC MECHANISMS HAVE BEEN PROPOSED, SUCH AS RETROGRADE MENSTRUATION, COELOMIC METAPLASIA, HORMONAL IMBALANCE, STEM CELL INVOLVEMENT, AND ALTERATIONS IN EPIGENETIC REGULATION. HOWEVER, THE UNDERLYING PATHOGENESIS OF ENDOMETRIOSIS REMAINS INADEQUATELY UNDERSTOOD. ELUCIDATION OF THE PRECISE MECHANISM OF THE DEVELOPMENT AND PROGRESSION OF ENDOMETRIOSIS IS CRUCIAL FOR EFFECTIVE TREATMENT. THIS REVIEW PRESENTS THE MAJOR PATHOGENETIC THEORIES OF ENDOMETRIOSIS BASED ON CURRENT RESEARCH STUDIES WITH A MAJOR FOCUS ON THE POTENTIAL ROLE OF UTERINE FACTORS. 2023 10 6237 32 THE MAIN THEORIES ON THE PATHOGENESIS OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A COMPLEX DISEASE, WHICH IS DEFINED BY ABNORMAL GROWTH OF ENDOMETRIAL TISSUE OUTSIDE THE UTERUS. IT AFFECTS ABOUT 10% OF WOMEN OF REPRODUCTIVE AGE ALL OVER THE WORLD. ENDOMETRIOSIS CAUSES SYMPTOMS THAT NOTABLY WORSEN PATIENT'S WELL-BEING-SUCH AS SEVERE PELVIC PAIN, DYSFUNCTION OF THE ORGANS OF PELVIC CAVITY, INFERTILITY AND SECONDARY MENTAL ISSUES. THE DIAGNOSIS OF ENDOMETRIOSIS IS QUITE OFTEN DELAYED BECAUSE OF NONSPECIFIC MANIFESTATIONS. SINCE THE DISEASE WAS DEFINED, SEVERAL DIFFERENT PATHOGENETIC PATHWAYS HAVE BEEN CONSIDERED, INCLUDING RETROGRADE MENSTRUATION, BENIGN METASTASIS, IMMUNE DYSREGULATION, COELOMIC METAPLASIA, HORMONAL DISBALANCE, INVOLVEMENT OF STEM CELLS AND ALTERATIONS IN EPIGENETIC REGULATION, BUT THE TRUE PATHOGENESIS OF ENDOMETRIOSIS REMAINS POORLY UNDERSTOOD. THE KNOWLEDGE OF THE EXACT MECHANISM OF THE ORIGIN AND PROGRESSION OF THIS DISEASE IS SIGNIFICANT FOR THE APPROPRIATE TREATMENT. THEREFORE, THIS REVIEW REPORTS THE MAIN PATHOGENETIC THEORIES OF ENDOMETRIOSIS BASED ON CURRENT STUDIES. 2023 11 1891 32 ENDOMETRIOSIS. PELVIC ENDOMETRIOSIS IS A COMPLEX SYNDROME CHARACTERIZED BY AN ESTROGEN-DEPENDENT CHRONIC INFLAMMATORY PROCESS THAT AFFECTS PRIMARILY PELVIC TISSUES, INCLUDING THE OVARIES. IT IS CAUSED WHEN SHED ENDOMETRIAL TISSUE TRAVELS RETROGRADE INTO THE LOWER ABDOMINAL CAVITY. ENDOMETRIOSIS IS THE MOST COMMON CAUSE OF CHRONIC PELVIC PAIN IN WOMEN AND IS ASSOCIATED WITH INFERTILITY. THE UNDERLYING PATHOLOGIC MECHANISMS IN THE INTRACAVITARY ENDOMETRIUM AND EXTRAUTERINE ENDOMETRIOTIC TISSUE INVOLVE DEFECTIVELY PROGRAMMED ENDOMETRIAL MESENCHYMAL PROGENITOR/STEM CELLS. ALTHOUGH ENDOMETRIOTIC STROMAL CELLS, WHICH COMPOSE THE BULK OF ENDOMETRIOTIC LESIONS, DO NOT CARRY SOMATIC MUTATIONS, THEY DEMONSTRATE SPECIFIC EPIGENETIC ABNORMALITIES THAT ALTER EXPRESSION OF KEY TRANSCRIPTION FACTORS. FOR EXAMPLE, GATA-BINDING FACTOR-6 OVEREXPRESSION TRANSFORMS AN ENDOMETRIAL STROMAL CELL TO AN ENDOMETRIOTIC PHENOTYPE, AND STEROIDOGENIC FACTOR-1 OVEREXPRESSION CAUSES EXCESSIVE PRODUCTION OF ESTROGEN, WHICH DRIVES INFLAMMATION VIA PATHOLOGICALLY HIGH LEVELS OF ESTROGEN RECEPTOR-BETA. PROGESTERONE RECEPTOR DEFICIENCY CAUSES PROGESTERONE RESISTANCE. POPULATIONS OF ENDOMETRIAL AND ENDOMETRIOTIC EPITHELIAL CELLS ALSO HARBOR MULTIPLE CANCER DRIVER MUTATIONS, SUCH AS KRAS, WHICH MAY BE ASSOCIATED WITH THE ESTABLISHMENT OF PELVIC ENDOMETRIOSIS OR OVARIAN CANCER. IT IS NOT KNOWN HOW INTERACTIONS BETWEEN EPIGENOMICALLY DEFECTIVE STROMAL CELLS AND THE MUTATED GENES IN EPITHELIAL CELLS CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. ENDOMETRIOSIS-ASSOCIATED PELVIC PAIN IS MANAGED BY SUPPRESSION OF OVULATORY MENSES AND ESTROGEN PRODUCTION, CYCLOOXYGENASE INHIBITORS, AND SURGICAL REMOVAL OF PELVIC LESIONS, AND IN VITRO FERTILIZATION IS FREQUENTLY USED TO OVERCOME INFERTILITY. ALTHOUGH NOVEL TARGETED TREATMENTS ARE BECOMING AVAILABLE, AS ENDOMETRIOSIS PATHOPHYSIOLOGY IS BETTER UNDERSTOOD, PREVENTIVE APPROACHES SUCH AS LONG-TERM OVULATION SUPPRESSION MAY PLAY A CRITICAL ROLE IN THE FUTURE. 2019 12 4310 29 MICRORNAS AND PROGESTERONE RECEPTOR SIGNALING IN ENDOMETRIOSIS PATHOPHYSIOLOGY. ENDOMETRIOSIS IS A SIGNIFICANT DISEASE CHARACTERIZED BY INFERTILITY AND PELVIC PAIN IN WHICH ENDOMETRIAL STROMAL AND GLANDULAR TISSUE GROW IN ECTOPIC LOCATIONS. ALTERED RESPONSIVENESS TO PROGESTERONE IS A CONTRIBUTING FACTOR TO ENDOMETRIOSIS PATHOPHYSIOLOGY, BUT THE PRECISE MECHANISMS ARE POORLY UNDERSTOOD. PROGESTERONE RESISTANCE INFLUENCES BOTH THE EUTOPIC AND ECTOPIC (ENDOMETRIOTIC LESION) ENDOMETRIUM. AN INABILITY OF THE EUTOPIC ENDOMETRIUM TO PROPERLY RESPOND TO PROGESTERONE IS BELIEVED TO CONTRIBUTE TO THE INFERTILITY ASSOCIATED WITH THE DISEASE, WHILE AN ALTERED RESPONSIVENESS OF ENDOMETRIOTIC LESION TISSUE MAY CONTRIBUTE TO THE SURVIVAL OF THE ECTOPIC TISSUE AND ASSOCIATED SYMPTOMS. WOMEN WITH ENDOMETRIOSIS EXPRESS ALTERED LEVELS OF SEVERAL ENDOMETRIAL PROGESTERONE TARGET GENES WHICH MAY BE DUE TO THE ABNORMAL EXPRESSION AND/OR FUNCTION OF PROGESTERONE RECEPTORS AND/OR CHAPERONE PROTEINS, AS WELL AS INFLAMMATION, GENETICS, AND EPIGENETICS. MIRNAS ARE A CLASS OF EPIGENETIC MODULATORS PROPOSED TO PLAY A ROLE IN ENDOMETRIOSIS PATHOPHYSIOLOGY, INCLUDING THE MODULATION OF PROGESTERONE SIGNALING. IN THIS PAPER, WE SUMMARIZE THE ROLE OF PROGESTERONE RECEPTORS AND PROGESTERONE SIGNALING IN ENDOMETRIOSIS PATHOPHYSIOLOGY, REVIEW MIRNAS, WHICH ARE OVER-EXPRESSED IN ENDOMETRIOSIS TISSUES AND FLUIDS, AND FOLLOW THIS WITH A DISCUSSION ON THE POTENTIAL REGULATION OF KEY PROGESTERONE SIGNALING COMPONENTS BY THESE MIRNAS, CONCLUDING WITH SUGGESTIONS FOR FUTURE RESEARCH ENDEAVORS IN THIS AREA. 2022 13 5241 29 PROGESTERONE RESISTANCE IN ENDOMETRIOSIS: CURRENT EVIDENCE AND PUTATIVE MECHANISMS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT DISEASE CHARACTERIZED BY THE GROWTH OF ENDOMETRIAL-LIKE TISSUE OUTSIDE THE UTERUS. PROGESTINS ARE CURRENTLY THE MOST COMMONLY USED TREATMENT FOR ENDOMETRIOSIS BECAUSE OF THEIR EXCELLENT THERAPEUTIC EFFECTS AND LIMITED SIDE EFFECTS. HOWEVER, PROGESTINS HAVE BEEN UNSUCCESSFUL IN SOME SYMPTOMATIC PATIENTS. THE INABILITY OF THE ENDOMETRIUM TO RESPOND PROPERLY TO PROGESTERONE IS KNOWN AS PROGESTERONE RESISTANCE. AN INCREASING BODY OF EVIDENCE SUGGESTS THE LOSS OF PROGESTERONE SIGNALING AND THE EXISTENCE OF PROGESTERONE RESISTANCE IN ENDOMETRIOSIS. THE MECHANISMS OF PROGESTERONE RESISTANCE HAVE RECEIVED CONSIDERABLE SCHOLARLY ATTENTION IN RECENT YEARS. ABNORMAL PGR SIGNALING, CHRONIC INFLAMMATION, ABERRANT GENE EXPRESSION, EPIGENETIC ALTERATIONS, AND ENVIRONMENTAL TOXINS ARE CONSIDERED POTENTIAL MOLECULAR CAUSES OF PROGESTERONE RESISTANCE IN ENDOMETRIOSIS. THE GENERAL OBJECTIVE OF THIS REVIEW WAS TO SUMMARIZE THE EVIDENCE AND MECHANISMS OF PROGESTERONE RESISTANCE. A DEEPER UNDERSTANDING OF HOW THESE MECHANISMS CONTRIBUTE TO PROGESTERONE RESISTANCE MAY HELP DEVELOP A NOVEL THERAPEUTIC REGIMEN FOR WOMEN WITH ENDOMETRIOSIS BY REVERSING PROGESTERONE RESISTANCE. 2023 14 2668 31 ESTROGEN RECEPTORS AND ENDOMETRIOSIS. ENDOMETRIOSIS IS A FREQUENT AND CHRONIC INFLAMMATORY DISEASE WITH IMPACTS ON REPRODUCTION, HEALTH AND QUALITY OF LIFE. THIS DISORDER IS HIGHLY ESTROGEN-DEPENDENT AND THE PURPOSE OF HORMONAL TREATMENTS IS TO DECREASE THE ENDOGENOUS OVARIAN PRODUCTION OF ESTROGENS. HIGH ESTROGEN PRODUCTION IS A CONSISTENTLY OBSERVED ENDOCRINE FEATURE OF ENDOMETRIOSIS. MRNA AND PROTEIN LEVELS OF ESTROGEN RECEPTORS (ER) ARE DIFFERENT BETWEEN A NORMAL HEALTHY ENDOMETRIUM AND ECTOPIC/EUTOPIC ENDOMETRIAL LESIONS: ENDOMETRIOTIC STROMAL CELLS EXPRESS EXTRAORDINARILY HIGHER ERBETA AND SIGNIFICANTLY LOWER ERALPHA LEVELS COMPARED WITH ENDOMETRIAL STROMAL CELLS. ABERRANT EPIGENETIC REGULATION SUCH AS DNA METHYLATION IN ENDOMETRIOTIC CELLS IS ASSOCIATED WITH THE PATHOGENESIS AND DEVELOPMENT OF ENDOMETRIOSIS. ALTHOUGH THERE IS A LARGE BODY OF DATA REGARDING ERS IN ENDOMETRIOSIS, OUR UNDERSTANDING OF THE ROLES OF ERALPHA AND ERBETA IN THE PATHOGENESIS OF ENDOMETRIOSIS REMAINS INCOMPLETE. THE GOAL OF THIS REVIEW IS TO PROVIDE AN OVERVIEW OF THE LINKS BETWEEN ENDOMETRIOSIS, ERS AND THE RECENT ADVANCES OF TREATMENT STRATEGIES BASED ON ERS MODULATION. WE WILL ALSO ATTEMPT TO SUMMARIZE THE CURRENT UNDERSTANDING OF THE MOLECULAR AND CELLULAR MECHANISMS OF ACTION OF ERS AND HOW THIS COULD PAVE THE WAY TO NEW THERAPEUTIC STRATEGIES. 2020 15 4438 19 MOLECULAR FINDINGS IN BARRETT'S EPITHELIUM. BARRETT'S METAPLASIA IS A PREMALIGNANT CONDITION AND REMAINS THE NUMBER ONE RISK FACTOR FOR DEVELOPING ADENOCARCINOMA. THE HISTOLOGIC CHANGES LEADING TO ADENOCARCINOMA ARE ACCOMPANIED BY GENETIC DISTURBANCES OF THE EPITHELIAL CELLS ITSELF AS WELL AS THE SURROUNDING STROMA. GENETIC AND EPIGENETIC EVENTS AFFECT THE CELL CYCLE, LEADING TO GROWTH SELF-SUFFICIENCY AND IGNORATION OF ANTIGROWTH SIGNALS. THE BALANCE OF CELL TURNOVER IS INSTABLE BY AVOIDANCE OF APOPTOSIS AND A GENERAL LIMITLESS OF THE REPLICATIVE POTENTIAL OF THE (MUTATED) STEM CELLS. SUSTAINED ANGIOGENESIS, NOT ONLY A CONSEQUENCE OF CHRONIC INFLAMMATION, MAY PRECEDE INVASION OF GENETICALLY INSTABLE (ANEUPLOID) CELLS. THE PRINCIPAL GENETIC CHANGES IN BARRETT'S CARCINOGENESIS ARE COMPARABLE TO THOSE KNOWN FROM OTHER EPITHELIAL MALIGNANCIES. LOSS OF P16 GENE EXPRESSION (BY DELETION OR HYPERMETHYLATION), THE LOSS OF P53 EXPRESSION (BY MUTATION AND DELETION), THE INCREASE IN CYCLIN EXPRESSION, AND THE LOSSES OF RB, APC AS WELL AS VARIOUS CHROMOSOMAL LOCI HAVE BEEN REPORTED. SINCE THESE GENETIC OR EPIGENETIC ALTERATIONS ARE NEITHER TUMOR NOR STAGE SPECIFIC, THEY COULD NOT GAIN DIAGNOSTIC SIGNIFICANCE AS BIOMARKERS UNTIL NOW. 2004 16 1892 24 ENDOMETRIOSIS: EPIDEMIOLOGY, CLASSIFICATION, PATHOGENESIS, TREATMENT AND GENETICS (REVIEW OF LITERATURE). ENDOMETRIOSIS IS A "MYSTERIOUS" DISEASE AND ITS EXACT CAUSE HAS NOT YET BEEN ESTABLISHED. AMONG THE ETIOLOGICAL FACTORS, CONGENITAL, ENVIRONMENTAL, EPIGENETIC, AUTOIMMUNE AND ALLERGIC FACTORS ARE LISTED. IT IS BELIEVED THAT THE PRIMARY MECHANISM OF THE FORMATION OF ENDOMETRIOSIS FOCI IS RETROGRADE MENSTRUATION, I.E., THE PASSAGE OF MENSTRUAL BLOOD THROUGH THE FALLOPIAN TUBES INTO THE PERITONEAL CAVITY AND IMPLANTATION OF EXFOLIATED ENDOMETRIAL CELLS. HOWEVER, SINCE THIS MECHANISM IS ALSO OBSERVED IN HEALTHY WOMEN, OTHER FACTORS MUST ALSO BE INVOLVED IN THE FORMATION OF ENDOMETRIOSIS FOCI. ENDOMETRIOSIS IS IN MANY WOMEN THE CAUSE OF INFERTILITY, CHRONIC PAIN AND THE DETERIORATION OF THE QUALITY OF LIFE. IT ALSO REPRESENTS A SIGNIFICANT FINANCIAL BURDEN ON HEALTH SYSTEMS. THE ARTICLE PRESENTS A REVIEW OF THE LITERATURE ON ENDOMETRIOSIS-A DISEASE AFFECTING WOMEN THROUGHOUT THE WORLD. 2021 17 5242 27 PROGESTERONE RESISTANCE IN ENDOMETRIOSIS: ORIGINS, CONSEQUENCES AND INTERVENTIONS. ENDOMETRIOSIS IS A COMMON CAUSE OF PELVIC PAIN AND AFFECTS UP TO 10% OF WOMEN OF REPRODUCTIVE AGE. ABERRANT PROGESTERONE SIGNALING IN THE ENDOMETRIUM PLAYS A SIGNIFICANT ROLE IN IMPAIRED DECIDUALIZATION AND ESTABLISHMENT OF ECTOPIC ENDOMETRIAL IMPLANTS. EUTOPIC ENDOMETRIAL CELLS FROM WOMEN WITH ENDOMETRIOSIS FAIL TO DOWNREGULATE GENES NEEDED FOR DECIDUALIZATION, SUCH AS THOSE INVOLVED IN CELL CYCLE REGULATION, LEADING TO UNBRIDLED PROLIFERATION. SEVERAL CAUSES OF PROGESTERONE RESISTANCE IN THE ENDOMETRIUM HAVE BEEN POSTULATED, INCLUDING CONGENITAL "PRECONDITIONING", WHEREBY THE IN UTERO ENVIRONMENT RENDERS INFANTS SUSCEPTIBLE TO NEONATAL UTERINE BLEEDING AND ENDOMETRIOSIS. PROGESTERONE ACTION IS CRUCIAL TO DECREASING INFLAMMATION IN THE ENDOMETRIUM, AND DEVIANT PROGESTERONE SIGNALING RESULTS IN A PROINFLAMMATORY PHENOTYPE. CONVERSELY, CHRONIC INFLAMMATION CAN INDUCE A PROGESTERONE-RESISTANT STATE. REPETITIVE RETROGRADE ENDOMETRIAL SHEDDING BEGETS CHRONIC PERITONEAL INFLAMMATION, WHICH FURTHER EXACERBATES PROGESTERONE RESISTANCE. GENETIC CAUSES OF PROGESTERONE RESISTANCE INCLUDE PROGESTERONE RECEPTOR GENE POLYMORPHISMS, ALTERED MICRORNA EXPRESSION, AND EPIGENETIC MODIFICATIONS TO PROGESTERONE RECEPTORS AND THEIR TARGETS. ENVIRONMENTAL TOXINS SUCH AS DIOXIN PLAY A POSSIBLE ROLE IN THE GENESIS OF ENDOMETRIOSIS BY PERMITTING AN INFLAMMATORY MILIEU. A CONSEQUENCE OF IMPAIRED PROGESTERONE ACTION IS THAT HORMONAL THERAPY IS RENDERED INEFFECTIVE FOR A SUBSET OF WOMEN WITH ENDOMETRIOSIS. SYNTHETIC PROGESTINS, SUCH AS DIENOGEST, MAY OVERCOME THIS PHENOMENON BY INCREASING PROGESTERONE RECEPTOR EXPRESSION AND DECREASING PROINFLAMMATORY CYTOKINES. OTHER MODALITIES INCLUDE HIGH DOSE DEPOT FORMULATIONS OF PROGESTINS, MEDICATED INTRAUTERINE DEVICES AND THE LIKELY ADVENT OF ORAL GNRH ANTAGONISTS. UNEARTHING ROOT CAUSES OF PROGESTERONE INACTION IN ENDOMETRIOSIS WILL AID IN THE DEVELOPMENT OF NOVEL THERAPEUTICS GEARED TOWARD PREVENTION AND TREATMENT. 2017 18 6796 34 [ENDOMETRIOSIS: A NEW APPROACH TO ETIOLOGY AND PATHOGENESIS (REVIEW)]. ENDOMETRIOSIS IS A DYSHORMONAL IMMUNE-DEPENDENT GENETICALLY DETERMINED DISEASE, WHICH APPEARS AS AN ENDOMETRIOID TISSUE THAT GROWS OUTSIDE THE UTERINE. ENDOMETRIOSIS IS ONE OF THE MOST URGENT PROBLEMS OF MEDICINE. TO DATE, NEW CONCEPTS OF THE ENDOMETRIOSIS ETIOLOGY AND PATHOGENESIS HAVE BEEN DEVELOPED, BUT, DESPITE THEIR ABUNDANCE, THERE IS NO UNIFIED THEORY. GENETIC AND EPIGENETIC FACTORS RESULT IN CHANGES IN AN EXPRESSION OF AROMATASE, STEROIDOGENIC FACTOR 1, AND ESTROGEN RECEPTORS ARE SUGGESTED TO BE THE MAIN CAUSE OF ENDOMETRIOSIS. THESE CHANGES LEAD TO AN ACTIVE SYNTHESIS OF VARIOUS PRO-INFLAMMATORY AGENTS AND A NERVE GROWTH FACTOR, THAT ARE IMPORTANT IN THE DEVELOPMENT OF PAIN SYNDROME. ALSO, CHANGES IN THE PROGESTERONE RECEPTOR FUNCTIONING AND THE LOCAL PROGESTERONE RESISTANCE DEVELOPMENT DECREASE THE ANTIPROLIFERATIVE ACTIVITY, APOPTOSIS, AND THE ANTI-INFLAMMATORY SUBSTANCES LEVEL, AS WELL AS INCREASE THE PROSTAGLANDIN, METALLOPROTEINASE ACTIVITY, AND LEVEL OF HYPOXIA FACTORS. IN ADDITION, THERE ARE SHREDS OF EVIDENCE THAT ENDOMETRIOSIS IS ASSOCIATED WITH THE RISK OF MALIGNANT TUMORS DEVELOPMENT, SO NEW CONCEPTS FOR UNDERSTANDING THESE MECHANISMS ARE ACTIVELY DEVELOPING. SOME OF THESE MECHANISMS ARE DISCUSSED IN THIS REVIEW. 2017 19 236 28 ADENOMYOSIS: MECHANISMS AND PATHOGENESIS. ADENOMYOSIS IS A COMMON DISORDER OF THE UTERUS, AND IS ASSOCIATED WITH AN ENLARGED UTERUS, HEAVY MENSTRUAL BLEEDING (HMB), PELVIC PAIN, AND INFERTILITY. IT IS CHARACTERIZED BY ENDOMETRIAL EPITHELIAL CELLS AND STROMAL FIBROBLASTS ABNORMALLY FOUND IN THE MYOMETRIUM WHERE THEY ELICIT HYPERPLASIA AND HYPERTROPHY OF SURROUNDING SMOOTH MUSCLE CELLS. WHILE BOTH THE MECHANISTIC PROCESSES AND THE PATHOGENESIS OF ADENOMYOSIS ARE UNCERTAIN, SEVERAL THEORIES HAVE BEEN PUT FORWARD ADDRESSING HOW THIS DISEASE DEVELOPS. THESE INCLUDE INTRINSIC OR INDUCED (1) MICROTRAUMA OF THE ENDOMETRIAL-MYOMETRIAL INTERFACE; (2) ENHANCED INVASION OF ENDOMETRIUM INTO MYOMETRIUM; (3) METAPLASIA OF STEM CELLS IN MYOMETRIUM; (4) INFILTRATION OF ENDOMETRIAL CELLS IN RETROGRADE MENSTRUAL EFFLUENT INTO THE UTERINE WALL FROM THE SEROSAL SIDE; (5) INDUCTION OF ADENOMYOTIC LESIONS BY ABERRANT LOCAL STEROID AND PITUITARY HORMONES; AND (6) ABNORMAL UTERINE DEVELOPMENT IN RESPONSE TO GENETIC AND EPIGENETIC MODIFICATIONS. DYSMENORRHEA, HMB, AND INFERTILITY ARE LIKELY RESULTS OF INFLAMMATION, NEUROGENESIS, ANGIOGENESIS, AND CONTRACTILE ABNORMALITIES IN THE ENDOMETRIAL AND MYOMETRIAL COMPONENTS. ELUCIDATING MECHANISMS UNDERLYING THE PATHOGENESIS OF ADENOMYOSIS RAISE POSSIBILITIES TO DEVELOP TARGETED THERAPIES TO AMELIORATE SYMPTOMS BEYOND THE CURRENT AGENTS THAT ARE LARGELY INEFFECTIVE. HEREIN, WE ADDRESS THESE POSSIBLE ETIOLOGIES AND DATA THAT SUPPORT UNDERLYING MECHANISMS. 2020 20 3003 56 GENETIC, EPIGENETIC AND STEM CELL ALTERATIONS IN ENDOMETRIOSIS: NEW INSIGHTS AND POTENTIAL THERAPEUTIC PERSPECTIVES. HUMAN ENDOMETRIUM IS A HIGHLY DYNAMIC TISSUE, UNDERGOING PERIODIC GROWTH AND REGRESSION AT EACH MENSTRUAL CYCLE. ENDOMETRIOSIS IS A FREQUENT CHRONIC PATHOLOGICAL STATUS CHARACTERIZED BY ENDOMETRIAL TISSUE WITH AN ECTOPIC LOCALIZATION, CAUSING PELVIC PAIN AND INFERTILITY AND A VARIABLE CLINICAL PRESENTATION. IN ADDITION, THERE IS WELL-ESTABLISHED EVIDENCE THAT, ALTHOUGH ENDOMETRIOSIS IS CONSIDERED BENIGN, IT IS ASSOCIATED WITH AN INCREASED RISK OF MALIGNANT TRANSFORMATION IN APPROXIMATELY 1.0% OF AFFECTED WOMEN, WITH THE INVOLVEMENT OF MULTIPLE PATHWAYS OF DEVELOPMENT. INCREASING EVIDENCE SUPPORTS A KEY CONTRIBUTION OF DIFFERENT STEM/PROGENITOR CELL POPULATIONS NOT ONLY IN THE CYCLIC REGENERATION OF EUTOPIC ENDOMETRIUM, BUT ALSO IN THE PATHOGENESIS OF AT LEAST SOME TYPES OF ENDOMETRIOSIS. EVIDENCE HAS ARISEN FROM EXPERIMENTS IN ANIMAL MODELS OF DISEASE THROUGH DIFFERENT KINDS OF ASSAYS (INCLUDING CLONOGENICITY, THE LABEL-RETAINING CELL APPROACH, THE ANALYSIS OF UNDIFFERENTIATION MARKERS), AS WELL AS FROM DESCRIPTIVE STUDIES ON ECTOPIC AND EUTOPIC TISSUE SAMPLES HARVESTED FROM AFFECTED WOMEN. CHANGES IN STEM CELL POPULATIONS IN ENDOMETRIOTIC LESIONS ARE ASSOCIATED WITH GENETIC AND EPIGENETIC ALTERATIONS, INCLUDING IMBALANCE OF MIRNA EXPRESSION, HISTONE AND DNA MODIFICATIONS AND CHROMOSOMAL ABERRATIONS. THE PRESENT SHORT REVIEW MAINLY SUMMARIZES THE LATEST OBSERVATIONS CONTRIBUTING TO THE CURRENT KNOWLEDGE REGARDING THE PRESENCE AND THE POTENTIAL CONTRIBUTION OF STEM/PROGENITOR CELLS IN EUTOPIC ENDOMETRIUM AND THE AETIOLOGY OF ENDOMETRIOSIS, TOGETHER WITH A REPORT OF THE MOST RECENTLY IDENTIFIED GENETIC AND EPIGENETIC ALTERATIONS IN ENDOMETRIOSIS. WE ALSO DESCRIBE THE POTENTIAL ADVANTAGES OF SINGLE CELL MOLECULAR PROFILING IN ENDOMETRIUM AND IN ENDOMETRIOTIC LESIONS. ALL THESE DATA CAN HAVE CLINICAL IMPLICATIONS AND PROVIDE A BASIS FOR NEW POTENTIAL THERAPEUTIC APPLICATIONS. 2014