1 6796 107 [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 2 1893 44 ENDOMETRIOSIS: NEW PERSPECTIVE FOR THE DIAGNOSIS OF CERTAIN CYTOKINES IN WOMEN AND ADOLESCENT GIRLS, AS WELL AS THE PROGRESSION OF DISEASE OUTGROWTH: A SYSTEMATIC REVIEW. ENDOMETRIOSIS IS A COMMON CHRONIC GYNECOLOGICAL DISORDER THAT UNDOUBTEDLY IMPACTS ON QUALITY OF LIFE, AND IS ONE OF THE MORE COMPLEX AND MYSTERIOUS ILLNESSES OF OUR CENTURY, WHICH IS ASSOCIATED WITH THE IMPROPER GROWTH OF ENDOMETRIAL TISSUE OUTSIDE OF THE UTERINE CAVITY. THIS PATHOLOGICALLY IMPLANTED TISSUE CAN BE FOUND MOST FREQUENTLY IN THE MINOR PELVIS, BUT ALSO IN THE PERITONEAL CAVITY, AND CAN AFFECT MANY ORGANS, LEADING TO CHRONIC PELVIC PAIN SYNDROME, INFERTILITY, AND DYSMENORRHEA. ENDOMETRIAL TISSUE IS A PARTICULARLY DYNAMIC TISSUE THAT HAS A DIRECT IMPACT ON THE PROGRESSION OF THE DISEASE, WITH ALTERED IMMUNITY, AS WELL AS CYTOKINE STORMS WITHIN THE METAPLASTIC ENDOMETRIOTIC SITE, AS POSSIBLE KEY FACTORS. CURRENTLY, DIAGNOSIS OF THIS MYSTERIOUS CHRONIC ILLNESS RELIES ON PERFORMING A LAPAROSCOPIC PROCEDURE WITH TISSUE SAMPLING. ONE OF THE MOST TROUBLESOME OUTCOMES OF THIS UNINTENDED PROGRESSION IS THAT WE LACK ANY SPECIFIC, SENSITIVE, NON-INVASIVE DIAGNOSTIC TOOLS. CURRENTLY, THE VAST MAJORITY OF REGIME STEWARDSHIP OPTIONS RELY ON ANTI-CONTRACEPTIVE DRUGS, OR OTHER REMEDIES THAT SUPPRESS THE RELEASE OF ESTROGEN THROUGH THE GONADS-ALTHOUGH IN MOST CLINICAL TRIALS, ENDOMETRIOSIS IS A CHRONIC PROGRESSIVE DISORDER THAT DEPENDS MOSTLY ON THE HIGH CONCENTRATION OF ESTROGEN. MOREOVER, MANY SPECIFIC TRIALS HAVE DEMONSTRATED THAT THE EUTOPIC ENDOMETRIAL CELLS IN INDIVIDUALS WITH ENDOMETRIOSIS REMAIN MUCH MORE RESISTANT TO THE IMMUNOLOGICAL ANNIHILATION PROCESS CAUSED BY CERTAIN ELEMENTS OF THE IMMUNE SYSTEM. NEVERTHELESS, EUTOPIC ENDOMETRIAL CELLS HAVE THE POTENTIAL TO SIMILARLY ESCALATE THE EXPRESSION OF AROMATASE RECEPTORS ON THE SURFACE OF THE PATHOLOGICAL CELLS, WHICH IN THE FINAL CASCADE CAUSE AN INCREASE IN THE CONCENTRATION OF ESTROGEN, AS WELL AS OTHER INFLAMMATORY PROTEINS THAT CONTRIBUTE TO PATHOLOGICAL OUTGROWTH. DATA REVEAL OCCURRENCE AMONG FIRST-DEGREE RELATIVES, SUGGESTING THAT THE SPECIFIC CASCADE COULD BE RELATED TO INHERITED AS WELL AS EPIGENETIC (ACQUIRED) MECHANISMS. IN WOMEN WITH THE DISEASE, CONFIRMED BY LAPAROSCOPIC PROCEDURES, DIAGNOSIS OF ENDOMETRIOSIS CAN BE ESTABLISHED ALSO VIA DETECTION BY GENE POLYMORPHISM IN THE GENES WHICH ARE RESPONSIBLE FOR RESPONSIBLE FOR THE DETOXIFICATION PHASE OF ESTROGEN RECEPTORS AND OTHER IMMUNOMODULATOR COMPONENTS. A RECENT PUBLICATION AIMS TO REVEAL A NEW PROSPECT FOR THE NON-INVASIVE DIAGNOSIS, DETECTION, AND ESTIMATION OF CERTAIN BIOMARKERS FOR MUCH MORE SPECIFIC INVESTIGATION OF THE DISEASE'S PROGRESSION. 2021 3 5788 20 SREBP1 DRIVES KERATIN-80-DEPENDENT CYTOSKELETAL CHANGES AND INVASIVE BEHAVIOR IN ENDOCRINE-RESISTANT ERALPHA BREAST CANCER. APPROXIMATELY 30% OF ERALPHA BREAST CANCER PATIENTS RELAPSE WITH METASTATIC DISEASE FOLLOWING ADJUVANT ENDOCRINE THERAPIES. THE CONNECTION BETWEEN ACQUISITION OF DRUG RESISTANCE AND INVASIVE POTENTIAL IS POORLY UNDERSTOOD. IN THIS STUDY, WE DEMONSTRATE THAT THE TYPE II KERATIN TOPOLOGICAL ASSOCIATING DOMAIN UNDERGOES EPIGENETIC REPROGRAMMING IN AROMATASE INHIBITORS (AI)-RESISTANT CELLS, LEADING TO KERATIN-80 (KRT80) UPREGULATION. KRT80 EXPRESSION IS DRIVEN BY DE NOVO ENHANCER ACTIVATION BY STEROL REGULATORY ELEMENT-BINDING PROTEIN 1 (SREBP1). KRT80 UPREGULATION DIRECTLY PROMOTES CYTOSKELETAL REARRANGEMENTS AT THE LEADING EDGE, INCREASED FOCAL ADHESION AND CELLULAR STIFFENING, COLLECTIVELY PROMOTING CANCER CELL INVASION. SHEARWAVE ELASTICITY IMAGING PERFORMED ON PROSPECTIVELY RECRUITED PATIENTS CONFIRMS KRT80 LEVELS CORRELATE WITH STIFFER TUMORS. IMMUNOHISTOCHEMISTRY SHOWED INCREASED KRT80-POSITIVE CELLS AT RELAPSE AND, USING SEVERAL CLINICAL ENDPOINTS, KRT80 EXPRESSION ASSOCIATES WITH POOR SURVIVAL. COLLECTIVELY, OUR DATA UNCOVER AN UNPREDICTED AND POTENTIALLY TARGETABLE DIRECT LINK BETWEEN EPIGENETIC AND CYTOSKELETAL REPROGRAMMING PROMOTING CELL INVASION IN RESPONSE TO CHRONIC AI TREATMENT. 2019 4 5239 35 PROGESTERONE ALLEVIATES ENDOMETRIOSIS VIA INHIBITION OF UTERINE CELL PROLIFERATION, INFLAMMATION AND ANGIOGENESIS IN AN IMMUNOCOMPETENT MOUSE MODEL. ENDOMETRIOSIS, DEFINED AS GROWTH OF THE ENDOMETRIAL CELLS OUTSIDE THE UTERUS, IS AN INFLAMMATORY DISORDER THAT IS ASSOCIATED WITH CHRONIC PELVIC PAIN AND INFERTILITY IN WOMEN OF CHILDBEARING AGE. ALTHOUGH THE ESTROGEN-DEPENDENCE OF ENDOMETRIOSIS IS WELL KNOWN, THE ROLE OF PROGESTERONE IN DEVELOPMENT OF THIS DISEASE REMAINS POORLY UNDERSTOOD. IN THIS STUDY, WE DEVELOPED A DISEASE MODEL IN WHICH ENDOMETRIOSIS WAS INDUCED IN THE PERITONEAL CAVITIES OF IMMUNOCOMPETENT FEMALE MICE, AND MAINTAINED WITH EXOGENOUS ESTROGEN. THE ENDOMETRIOSIS-LIKE LESIONS THAT WERE IDENTIFIED AT A VARIETY OF ECTOPIC LOCATIONS EXHIBITED ABUNDANT BLOOD SUPPLY AND EXTENSIVE ADHESIONS. HISTOLOGICAL EXAMINATION REVEALED THAT THESE LESIONS HAD A WELL-ORGANIZED ENDOMETRIAL ARCHITECTURE AND FIBROTIC RESPONSE, RESEMBLING THOSE RECOVERED FROM CLINICAL PATIENTS. IN ADDITION, AN EXTENSIVE PROLIFERATION, INFLAMMATORY RESPONSE, AND LOSS OF ESTROGEN RECEPTOR ALPHA (ERALPHA) AND PROGESTERONE RECEPTOR (PR) EXPRESSION WERE ALSO OBSERVED IN THESE LESIONS. INTERESTINGLY, ADMINISTRATION OF PROGESTERONE BEFORE, BUT NOT AFTER, LESION INDUCTION SUPPRESSED LESION EXPANSION AND MAINTAINED ERALPHA AND PR EXPRESSIONS. THESE PROGESTERONE-PRETREATED LESIONS EXHIBITED ATTENUATION IN KI67, CD31, AND PRO-INFLAMMATORY CYTOKINE EXPRESSION AS WELL AS MACROPHAGE INFILTRATION, INDICATING THAT PROGESTERONE AMELIORATES ENDOMETRIOSIS PROGRESSION BY INHIBITING CELL PROLIFERATION, INFLAMMATION AND NEOVASCULARIZATION. OUR STUDIES FURTHER SHOWED THAT SUPPRESSION OF GLOBAL DNA METHYLATION BY APPLICATION OF DNA METHYLTRANSFERASE INHIBITOR TO FEMALE MICE BEARING ECTOPIC LESIONS RESTRAINED LESION EXPANSION AND RESTORED ERALPHA AND PR EXPRESSION IN EUTOPIC ENDOMETRIUM AND ECTOPIC LESIONS. THESE RESULTS INDICATE THAT EPIGENETIC REGULATION OF TARGET GENE EXPRESSION VIA DNA METHYLATION CONTRIBUTES, AT LEAST IN PART, TO PROGESTERONE RESISTANCE IN ENDOMETRIOSIS. 2016 5 1891 35 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 6 166 29 ABNORMAL OVARIAN DNA METHYLATION PROGRAMMING DURING GONAD MATURATION IN WILD CONTAMINATED FISH. THERE IS INCREASING EVIDENCE THAT POLLUTANTS MAY CAUSE DISEASES VIA EPIGENETIC MODIFICATIONS. EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION PARTICIPATE IN THE REGULATION OF GENE TRANSCRIPTION. SURPRISINGLY, EPIGENETICS RESEARCH IS STILL LIMITED IN ECOTOXICOLOGY. IN THIS STUDY, WE INVESTIGATED WHETHER CHRONIC EXPOSURE TO CONTAMINANTS EXPERIENCED BY WILD FEMALE FISH (ANGUILLA ANGUILLA) THROUGHOUT THEIR JUVENILE PHASE CAN AFFECT THE DNA METHYLATION STATUS OF THEIR OOCYTES DURING GONAD MATURATION. THUS, FISH WERE SAMPLED IN TWO LOCATIONS PRESENTING A LOW OR A HIGH CONTAMINATION LEVEL. THEN, FISH WERE TRANSFERRED TO THE LABORATORY AND ARTIFICIALLY MATURED. BEFORE HORMONAL TREATMENT, THE DNA METHYLATION LEVELS OF THE GENES ENCODING FOR THE AROMATASE AND THE RECEPTOR OF THE FOLLICLE STIMULATING HORMONE WERE HIGHER IN CONTAMINATED FISH THAN IN FISH FROM THE CLEAN SITE. FOR THE HORMONE RECEPTOR, THIS HYPERMETHYLATION WAS POSITIVELY CORRELATED WITH THE CONTAMINATION LEVEL OF FISH AND WAS ASSOCIATED WITH A DECREASE IN ITS TRANSCRIPTION LEVEL. IN ADDITION, WHEREAS GONAD GROWTH WAS ASSOCIATED WITH AN INCREASE IN DNA METHYLATION IN FISH FROM THE CLEAN SITE, NO CHANGES WERE OBSERVED IN CONTAMINATED FISH IN RESPONSE TO HORMONAL TREATMENT. FINALLY, A HIGHER GONAD GROWTH WAS OBSERVED IN FISH FROM THE REFERENCE SITE IN COMPARISON TO CONTAMINATED FISH. 2014 7 603 31 BETULINIC ACID INHIBITS ENDOMETRIOSIS THROUGH SUPPRESSION OF ESTROGEN RECEPTOR BETA SIGNALING PATHWAY. ENDOMETRIOSIS IS AN INFLAMMATORY GYNECOLOGICAL DISORDER CHARACTERIZED BY ENDOMETRIAL TISSUE GROWTH LOCATED OUTSIDE OF THE UTERINE CAVITY IN ADDITION TO CHRONIC PELVIC PAIN AND INFERTILITY. IN THIS STUDY, WE AIM TO DEVELOP A POTENTIAL THERAPEUTIC TREATMENT BASED ON THE PATHOGENESIS AND MECHANISM OF ENDOMETRIOSIS. OUR PRELIMINARY DATA SHOWED THAT THE EXPRESSION OF ESTROGEN RECEPTOR BETA (ERBETA) WAS SIGNIFICANTLY INCREASED, WHILE ERALPHA WAS SIGNIFICANTLY DECREASED, IN ENDOMETRIOTIC CELLS COMPARED TO NORMAL ENDOMETRIAL CELLS. FURTHER INVESTIGATION SHOWED THAT BETULINIC ACID (BA) TREATMENT SUPPRESSED ERBETA EXPRESSION THROUGH EPIGENETIC MODIFICATION ON THE ERBETA PROMOTER, WHILE HAD NO EFFECT ON ERALPHA EXPRESSION. IN ADDITION, BA TREATMENT SUPPRESSES ERBETA TARGET GENES, INCLUDING SUPEROXIDE DISMUTASE 2 (SOD2), NUCLEAR RESPIRATORY FACTOR-1 (NRF1), CYCLOOXYGENASE 2 (COX2), AND MATRIX METALLOPROTEINASE-1 (MMP1), SUBSEQUENTLY INCREASING OXIDATIVE STRESS, TRIGGERING MITOCHONDRIAL DYSFUNCTION, DECREASING ELEVATED PROINFLAMMATORY CYTOKINES, AND EVENTUALLY SUPPRESSING ENDOMETRIOTIC CELL PROLIFERATION, MIMICKING THE EFFECT OF ERBETA KNOCKDOWN. ON THE OTHER HAND, GAIN OF ERBETA BY LENTIVIRUS INFECTION IN NORMAL ENDOMETRIAL CELLS RESULTED IN INCREASED CELL PROLIFERATION AND PROINFLAMMATORY CYTOKINE RELEASE, WHILE BA TREATMENT DIMINISHED THIS EFFECT THROUGH ERBETA SUPPRESSION WITH SUBSEQUENT OXIDATIVE STRESS AND APOPTOSIS. OUR RESULTS INDICATE THAT ERBETA MAY BE A MAJOR DRIVING FORCE FOR THE DEVELOPMENT OF ENDOMETRIOSIS, WHILE BA INHIBITS ENDOMETRIOSIS THROUGH SPECIFIC SUPPRESSION OF THE ERBETA SIGNALING PATHWAY. THIS STUDY PROVIDES A NOVEL THERAPEUTIC STRATEGY FOR ENDOMETRIOSIS TREATMENT THROUGH BA-MEDIATED ERBETA SUPPRESSION. 2020 8 5242 29 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 9 4310 36 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 10 2668 27 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 11 5241 34 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 12 1889 34 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 13 2602 38 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 14 2575 30 EPIGENETICS OF ESTROGEN AND PROGESTERONE RECEPTORS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT INFLAMMATORY GYNECOLOGICAL DISEASE. INCREASED ESTROGEN ACTIVITY AND PROGESTERONE RESISTANCE ARE THE MAIN HORMONAL SUBSTRATE OF THIS DISEASE AND ARE ASSOCIATED WITH INFLAMMATORY RESPONSE AND DEBILITATING SYMPTOMS, INCLUDING PAIN AND INFERTILITY. ESTROGENS AND PROGESTERONE ACT VIA THEIR SPECIFIC NUCLEAR RECEPTORS. THE REGULATION OF RECEPTOR EXPRESSION BY EPIGENETICS MAYBE A CRITICAL FACTOR FOR ENDOMETRIOSIS. THE PRESENT REVIEW AIMS TO DISCUSS THE EPIGENETIC MECHANISMS RELATED TO THE EXPRESSION OF ESTROGEN RECEPTORS (ERS) AND PROGESTERONE RECEPTORS (PRS) IN PATIENTS WITH ENDOMETRIOSIS, INCLUDING TWO CLASSIC EPIGENETIC MECHANISMS: DNA METHYLATION AND HISTONE MODIFICATION, AND, OTHER NON-CLASSIC MECHANISMS: MIRNAS AND LNCRNA. SEVERAL IN VITRO AND IN VIVO STUDIES SUPPORT THE KEY ROLE OF EPIGENETICS IN THE REGULATION OF THE EXPRESSION OF ERS AND PRS, WHICH MAY PROVIDE NEW MOLECULES AND TARGETS FOR THE DIAGNOSIS AND TREATMENT OF ENDOMETRIOSIS. 2020 15 3667 29 INFILTRATING MACROPHAGES INDUCE ERALPHA EXPRESSION THROUGH AN IL17A-MEDIATED EPIGENETIC MECHANISM TO SENSITIZE ENDOMETRIAL CANCER CELLS TO ESTROGEN. PERSISTENT UNOPPOSED ESTROGEN STIMULATION IS A CENTRAL ONCOGENIC MECHANISM DRIVING THE FORMATION OF TYPE I ENDOMETRIAL CANCER. RECENT EPIDEMIOLOGIC AND CLINICAL STUDIES OF ENDOMETRIAL CANCER HAVE ALSO REVEALED A ROLE FOR INSULIN RESISTANCE, CLINICALLY MANIFESTED BY CHRONIC INFLAMMATION. HOWEVER, THE ROLE OF INFLAMMATION IN ESTROGEN-DRIVEN ENDOMETRIAL CANCER IS NOT WELL CHARACTERIZED. IN THIS STUDY, WE INVESTIGATED THE ASSOCIATION BETWEEN INFILTRATING MACROPHAGES AND ESTROGEN SENSITIVITY IN ENDOMETRIAL CANCER. EVALUATING TISSUE SAMPLES AND SERUM FROM PATIENTS WITH PRECANCEROUS LESIONS OR ENDOMETRIAL CANCER, WE FOUND THAT TISSUE MACROPHAGE INFILTRATION, BUT NOT SERUM ESTRADIOL LEVELS, CORRELATED POSITIVELY WITH ENDOMETRIAL CANCER DEVELOPMENT. FURTHERMORE, IL4/IL13-INDUCED CD68(+)CD163(+) MACROPHAGES ENHANCED THE PROLIFERATIVE EFFECTS OF ESTRADIOL IN ENDOMETRIAL CANCER CELLS BY UPREGULATING ESTROGEN RECEPTOR ALPHA (ERALPHA), BUT NOT ERBETA. MECHANISTIC INVESTIGATIONS REVEALED THAT CD68(+)CD163(+) MACROPHAGES SECRETED CYTOKINES, SUCH AS IL17A, THAT UPREGULATED ERALPHA EXPRESSION THROUGH TET1-MEDIATED EPIGENETIC MODULATION OF THE ERALPHA GENE. OVERALL, OUR FINDINGS SHOW HOW CYTOKINES PRODUCED BY INFILTRATING MACROPHAGES IN THE ENDOMETRIAL MICROENVIRONMENT CAN INDUCE EPIGENETIC UPREGULATION OF ERALPHA EXPRESSION, WHICH IN TURN SENSITIZES ENDOMETRIAL CELLS TO ESTROGEN STIMULATION. THE CONCEPT THAT INFLAMMATION-INDUCED ESTROGEN SENSITIVITY IN THE ENDOMETRIUM ACTS AS A DRIVER OF TYPE I ENDOMETRIAL CANCER HAS IMPLICATIONS FOR INFILTRATING MACROPHAGES AS A PROGNOSTIC BIOMARKER OF PROGRESSION IN THIS DISEASE SETTING. 2016 16 6272 27 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 17 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 18 3999 27 LOSS OF HDAC3 RESULTS IN NONRECEPTIVE ENDOMETRIUM AND FEMALE INFERTILITY. ENDOMETRIOSIS IS A DISEASE IN WHICH TISSUE THAT NORMALLY GROWS INSIDE THE UTERUS GROWS OUTSIDE THE UTERUS AND CAUSES CHRONIC PELVIC PAIN AND INFERTILITY. HOWEVER, THE EXACT MECHANISMS OF THE PATHOGENESIS OF ENDOMETRIOSIS-ASSOCIATED INFERTILITY ARE UNKNOWN. EPIGENETIC DYSREGULATION HAS RECENTLY BEEN IMPLICATED IN INFERTILITY. HERE, WE REPORT A REDUCTION OF HISTONE DEACETYLASE 3 (HDAC3) PROTEIN AMOUNTS IN EUTOPIC ENDOMETRIUM OF INFERTILE WOMEN WITH ENDOMETRIOSIS COMPARED TO A CONTROL GROUP. TO INVESTIGATE THE EFFECT OF HDAC3 LOSS IN THE UTERUS, WE GENERATED MICE WITH CONDITIONAL ABLATION OF HDAC3 IN PROGESTERONE RECEPTOR (PGR)-POSITIVE CELLS (PGR(CRE/+)HDAC3(F/F) ; HDAC3(D/D) ). LOSS OF HDAC3 IN THE UTERUS OF MICE RESULTS IN INFERTILITY DUE TO IMPLANTATION FAILURE AND DECIDUALIZATION DEFECT. EXPRESSION MICROARRAY AND CHIP-SEQ ANALYSES IDENTIFIED COL1A1 AND COL1A2 AS DIRECT TARGETS OF HDAC3 IN BOTH MICE AND HUMANS. REDUCTION OF HDAC3 ABROGATED DECIDUALIZATION IN A PRIMARY CULTURE OF HUMAN ENDOMETRIAL STROMAL CELLS (HESCS) SIMILAR TO THAT OBSERVED IN INFERTILE PATIENTS WITH ENDOMETRIOSIS. WHEREAS ATTENUATION OF HDAC3 RESULTED IN P300 RECRUITMENT TO COL1A1 AND COL1A2 GENES IN THE UTERUS OF MICE AS WELL AS HESCS, INHIBITION OF P300 PERMITTED HESCS TO UNDERGO DECIDUALIZATION. COLLECTIVELY, WE FOUND ATTENUATION OF HDAC3 AND OVEREXPRESSION OF COLLAGEN TYPE I IN THE EUTOPIC ENDOMETRIUM OF INFERTILE PATIENTS WITH ENDOMETRIOSIS. HDAC3 LOSS CAUSED A DEFECT OF DECIDUALIZATION THROUGH THE ABERRANT TRANSCRIPTIONAL ACTIVATION OF COL1A1 AND COL1A2 GENES IN MICE AND COL1A1 AND COL1A2 GENES IN HUMANS. OUR RESULTS SUGGEST THAT HDAC3 IS CRITICAL FOR ENDOMETRIAL RECEPTIVITY AND DECIDUALIZATION. 2019 19 1840 30 EFFECTS OF SELECTIVE INHIBITION OF PROSTAGLANDIN E2 RECEPTORS EP2 AND EP4 ON THE MIRNA PROFILE IN ENDOMETRIOSIS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT, PROGESTERONE-RESISTANT, CHRONIC INFLAMMATORY GYNECOLOGICAL DISEASE OF REPRODUCTIVE-AGE WOMEN. TWO MAJOR CLINICAL SYMPTOMS OF ENDOMETRIOSIS ARE CHRONIC PELVIC PAIN AND INFERTILITY, WHICH PROFOUNDLY AFFECT THE QUALITY OF LIFE IN WOMEN. CURRENT HORMONAL THERAPIES TO INDUCE A HYPOESTROGENIC STATE ARE UNSUCCESSFUL BECAUSE OF UNDESIRABLE SIDE EFFECTS, REPRODUCTIVE HEALTH CONCERNS, AND FAILURE TO PREVENT DISEASE RECURRENCE. PROSTAGLANDIN E(2) (PGE(2)) PLAYS AN IMPORTANT ROLE IN THE SURVIVAL AND GROWTH OF ENDOMETRIOTIC LESIONS. MICRORNAS (MIRNAS) ARE SMALL, NONCODING RNAS THAT CONTROL GENE EXPRESSIONS THROUGH MULTIPLE MECHANISMS AND HAVE IMPORTANT ROLES IN THE PATHOGENESIS OF ENDOMETRIOSIS. THE OBJECTIVE OF THE PRESENT STUDY IS TO DETERMINE THE EFFECTS OF PHARMACOLOGICAL INHIBITION OF PGE(2) RECEPTORS, EP2 AND EP4, ON MIRNA PROFILE IN ENDOMETRIOSIS. THE NOVEL RESULTS COLLECTIVELY INDICATE THAT INHIBITION OF PGE(2)-EP2/EP4 SIGNALING REGULATED SEVERAL MIRNA CLUSTERS ASSOCIATED WITH CELL ADHESION, MIGRATION, INVASION, SURVIVAL AND GROWTH IN CELL-SPECIFIC AND THE CHROMOSOME-SPECIFIC MANNER AND REVERSES THE EPIGENETIC SILENCING OF PROAPOPTOTIC MIRNAS 15A AND 34C IN THE HUMAN ENDOMETRIOTIC EPITHELIAL AND STROMAL CELLS AND EXPERIMENTAL ENDOMETRIOTIC LESIONS. THUS, SELECTIVE INHIBITION OF EP2/EP4 RECEPTORS COULD EMERGE AS A POTENTIAL NONSTEROIDAL THERAPY FOR ENDOMETRIOSIS. 2022 20 4129 28 MECHANISMS OF ENDOMETRIAL PROGESTERONE RESISTANCE. THROUGHOUT THE REPRODUCTIVE YEARS, THE RISE AND FALL IN OVARIAN HORMONES ELICIT IN THE ENDOMETRIUM WAVES OF CELL PROLIFERATION, DIFFERENTIATION, RECRUITMENT OF INFLAMMATORY CELLS, APOPTOSIS, TISSUE BREAKDOWN AND REGENERATION. THE ACTIVATED PROGESTERONE RECEPTOR, A MEMBER OF THE SUPERFAMILY OF LIGAND-DEPENDENT TRANSCRIPTION FACTORS, IS THE MASTER REGULATOR OF THIS INTENSE TISSUE REMODELLING PROCESS IN THE UTERUS. ITS ACTIVITY IS TIGHTLY REGULATED BY INTERACTION WITH CELL-SPECIFIC TRANSCRIPTION FACTORS AND COREGULATORS AS WELL AS BY SPECIFIC POSTTRANSLATIONAL MODIFICATIONS THAT RESPOND DYNAMICALLY TO A VARIETY OF ENVIRONMENTAL AND INFLAMMATORY SIGNALS. ENDOMETRIOSIS, A CHRONIC INFLAMMATORY DISORDER, DISRUPTS COORDINATED PROGESTERONE RESPONSES THROUGHOUT THE REPRODUCTIVE TRACT, INCLUDING IN THE ENDOMETRIUM. THIS PHENOMENON IS INCREASINGLY REFERRED TO AS 'PROGESTERONE RESISTANCE'. EMERGING EVIDENCE SUGGESTS THAT PROGESTERONE RESISTANCE IN ENDOMETRIOSIS IS NOT JUST A CONSEQUENCE OF PERTURBED PROGESTERONE SIGNAL TRANSDUCTION CAUSED BY CHRONIC INFLAMMATION BUT ASSOCIATED WITH EPIGENETIC CHROMATIN CHANGES THAT DETERMINE THE INTRINSIC RESPONSIVENESS OF ENDOMETRIAL CELLS TO DIFFERENTIATION CUES. 2012