1 3999 118 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 2 5239 39 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 3 3667 33 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 4 468 38 ARGININE METHYLTRANSFERASES MEDIATE AN EPIGENETIC OVARIAN RESPONSE TO ENDOMETRIOSIS. ENDOMETRIOSIS IS ASSOCIATED WITH INFERTILITY AND DEBILITATING CHRONIC PAIN. ABNORMAL EPIGENETIC MODIFICATIONS IN THE HUMAN ENDOMETRIUM HAVE RECENTLY BEEN IMPLICATED IN THE PATHOGENESIS OF THIS CONDITION. HOWEVER, WHETHER AN ALTERED EPIGENETIC LANDSCAPE CONTRIBUTES TO PATHOLOGICAL CHANGES IN THE OVARY IS UNKNOWN. USING AN ESTABLISHED BABOON ENDOMETRIOSIS MODEL, EARLY-, AND LATE-STAGE EPIGENETIC CHANGES IN THE OVARY WERE INVESTIGATED. TRANSCRIPT PROFILING OF KEY CHROMATIN-MODIFYING ENZYMES USING PATHWAY-FOCUSED PCR ARRAYS ON OVARIAN TISSUE FROM HEALTHY CONTROL ANIMALS AND AT 3 AND 15 MONTHS OF ENDOMETRIOSIS REVEALED DRAMATIC CHANGES IN GENE EXPRESSION IN A DISEASE DURATION-DEPENDENT MANNER. INGENUITY PATHWAY ANALYSIS INDICATED THAT TRANSCRIPTS FOR CHROMATIN-REMODELING ENZYMES ASSOCIATED WITH REPRODUCTIVE SYSTEM DISEASE AND CANCER DEVELOPMENT WERE ABNORMALLY REGULATED, MOST PROMINENTLY THE ARGININE METHYLTRANSFERASES CARM1, PRMT2, AND PRMT8. DOWNREGULATION OF CARM1 PROTEIN EXPRESSION WAS ALSO DETECTED IN THE OVARY, FULLY-GROWN OOCYTES AND EUTOPIC ENDOMETRIUM FOLLOWING 15 MONTHS OF ENDOMETRIOSIS. SODIUM BISULFITE SEQUENCING REVEALED DNA HYPERMETHYLATION WITHIN THE PRMT8 PROMOTER, SUGGESTING THAT DEREGULATED CPG METHYLATION MAY PLAY A ROLE IN TRANSCRIPTIONAL REPRESSION OF THIS GENE. THESE RESULTS DEMONSTRATE THAT ENDOMETRIOSIS IS ASSOCIATED WITH CHANGES OF EPIGENETIC PROFILES IN THE PRIMATE OVARY AND SUGGEST THAT ARGININE METHYLTRANSFERASES PLAY A PROMINENT ROLE IN MEDIATING THE OVARIAN RESPONSE TO ENDOMETRIOSIS. OWING TO THE CRITICAL ROLE OF CARM1 IN NUCLEAR RECEPTOR-MEDIATED TRANSCRIPTION AND MAINTENANCE OF PLURIPOTENCY IN THE CLEAVAGE STAGE EMBRYO, OUR RESULTS SUGGEST THAT EPIGENETIC ALTERATIONS IN THE OVARY MAY HAVE FUNCTIONAL CONSEQUENCES FOR OOCYTE QUALITY AND THE ETIOLOGY OF INFERTILITY ASSOCIATED WITH ENDOMETRIOSIS. 2015 5 3061 36 GENOME-WIDE DNA METHYLATION ANALYSIS PREDICTS AN EPIGENETIC SWITCH FOR GATA FACTOR EXPRESSION IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A GYNECOLOGICAL DISEASE DEFINED BY THE EXTRAUTERINE GROWTH OF ENDOMETRIAL-LIKE CELLS THAT CAUSE CHRONIC PAIN AND INFERTILITY. THE DISEASE IS LIMITED TO PRIMATES THAT EXHIBIT SPONTANEOUS DECIDUALIZATION, AND DISEASED CELLS ARE CHARACTERIZED BY SIGNIFICANT DEFECTS IN THE STEROID-DEPENDENT GENETIC PATHWAYS THAT TYPIFY THIS PROCESS. ALTERED DNA METHYLATION MAY UNDERLIE THESE DEFECTS, BUT FEW REGIONS WITH DIFFERENTIAL METHYLATION HAVE BEEN IMPLICATED IN THE DISEASE. WE MAPPED GENOME-WIDE DIFFERENCES IN DNA METHYLATION BETWEEN HEALTHY HUMAN ENDOMETRIAL AND ENDOMETRIOTIC STROMAL CELLS AND CORRELATED THIS WITH GENE EXPRESSION USING AN INTERACTION ANALYSIS STRATEGY. WE IDENTIFIED 42,248 DIFFERENTIALLY METHYLATED CPGS IN ENDOMETRIOSIS COMPARED TO HEALTHY CELLS. THESE EXTENSIVE DIFFERENCES WERE NOT UNIDIRECTIONAL, BUT WERE FOCUSED INTRAGENICALLY AND AT SITES DISTAL TO CLASSIC CPG ISLANDS WHERE METHYLATION STATUS WAS TYPICALLY NEGATIVELY CORRELATED WITH GENE EXPRESSION. SIGNIFICANT DIFFERENCES IN METHYLATION WERE MAPPED TO 403 GENES, WHICH INCLUDED A DISPROPORTIONALLY LARGE NUMBER OF TRANSCRIPTION FACTORS. FURTHERMORE, MANY OF THESE GENES ARE IMPLICATED IN THE PATHOLOGY OF ENDOMETRIOSIS AND DECIDUALIZATION. OUR RESULTS TREMENDOUSLY IMPROVE THE SCOPE AND RESOLUTION OF DIFFERENTIAL METHYLATION AFFECTING THE HOX GENE CLUSTERS, NUCLEAR RECEPTOR GENES, AND INTRIGUINGLY THE GATA FAMILY OF TRANSCRIPTION FACTORS. FUNCTIONAL ANALYSIS OF THE GATA FAMILY REVEALED THAT GATA2 REGULATES KEY GENES NECESSARY FOR THE HORMONE-DRIVEN DIFFERENTIATION OF HEALTHY STROMAL CELLS, BUT IS HYPERMETHYLATED AND REPRESSED IN ENDOMETRIOTIC CELLS. GATA6, WHICH IS HYPOMETHYLATED AND ABUNDANT IN ENDOMETRIOTIC CELLS, POTENTLY BLOCKED HORMONE SENSITIVITY, REPRESSED GATA2, AND INDUCED MARKERS OF ENDOMETRIOSIS WHEN EXPRESSED IN HEALTHY ENDOMETRIAL CELLS. THE UNIQUE EPIGENETIC FINGERPRINT IN ENDOMETRIOSIS SUGGESTS DNA METHYLATION IS AN INTEGRAL COMPONENT OF THE DISEASE, AND IDENTIFIES A NOVEL ROLE FOR THE GATA FAMILY AS KEY REGULATORS OF UTERINE PHYSIOLOGY-ABERRANT DNA METHYLATION IN ENDOMETRIOTIC CELLS CORRELATES WITH A SHIFT IN GATA ISOFORM EXPRESSION THAT FACILITATES PROGESTERONE RESISTANCE AND DISEASE PROGRESSION. 2014 6 146 29 ABERRANT ENDOMETRIAL DNA METHYLOME AND ASSOCIATED GENE EXPRESSION IN WOMEN WITH ENDOMETRIOSIS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT, PROGESTERONE-RESISTANT DISORDER LARGELY DERIVED FROM RETROGRADE TRANSPLANTATION OF MENSTRUAL TISSUE/CELLS INTO THE PELVIS, ELICITING AN INFLAMMATORY RESPONSE, PELVIC PAIN, AND INFERTILITY. EUTOPIC ENDOMETRIUM (WITHIN THE UTERUS), GIVING RISE TO PELVIC DISEASE, DISPLAYS CYCLE-DEPENDENT TRANSCRIPTOMIC, PROTEOMIC, AND SIGNALING ABNORMALITIES, AND ALTHOUGH ITS DNA METHYLATION PROFILES DYNAMICALLY CHANGE ACROSS THE CYCLE IN HEALTHY WOMEN, STUDIES IN ENDOMETRIOSIS ARE LIMITED. HEREIN, WE INVESTIGATED THE DNA METHYLOME AND ASSOCIATED GENE EXPRESSION IN THREE PHASES OF THE CYCLE IN EUTOPIC ENDOMETRIUM OF WOMEN WITH SEVERE ENDOMETRIOSIS VERSUS CONTROLS, MATCHED FOR ETHNICITY, MEDICATIONS, SMOKING, AND NO RECENT CONTRACEPTIVE STEROID USE. GENOME-WIDE DNA METHYLATION AND GENE EXPRESSION WERE COASSESSED IN EACH SAMPLE. CYCLE PHASE WAS DETERMINED BY HISTOLOGY, SERUM HORMONE LEVELS, AND UNSUPERVISED PRINCIPAL COMPONENT AND HIERARCHICAL CLUSTER ANALYSES OF MICROARRAY DATA. ALTERED ENDOMETRIAL DNA METHYLATION IN ENDOMETRIOSIS WAS MOST PROMINENT IN THE MIDSECRETORY PHASE (PEAK PROGESTERONE), WITH DISRUPTION OF THE NORMAL PATTERN OF CYCLE-DEPENDENT DNA METHYLATION CHANGES, INCLUDING A BIAS TOWARD METHYLATION OF CPG ISLANDS, SUGGESTING WIDE-RANGE ABNORMALITIES OF THE CHROMATIN REMODELING MACHINERY IN ENDOMETRIOSIS. DNA METHYLATION CHANGES WERE ASSOCIATED WITH ALTERED GENE EXPRESSION RELEVANT TO ENDOMETRIAL FUNCTION/DYSFUNCTION, INCLUDING CELL PROLIFERATION, INFLAMMATION/IMMUNE RESPONSE, ANGIOGENESIS, AND STEROID HORMONE RESPONSE. THE DATA PROVIDE INSIGHT INTO EPIGENETIC REPROGRAMMING AND STEROID HORMONE ACTIONS IN ENDOMETRIUM CONTRIBUTING TO THE PATHOGENESIS AND PATHOPHYSIOLOGY OF ENDOMETRIOSIS. 2016 7 5242 32 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 8 1840 35 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 9 5754 20 SOCIAL PSYCHOGENIC STRESS PROMOTES THE DEVELOPMENT OF ENDOMETRIOSIS IN MOUSE. EXPOSURE TO CHRONIC STRESS BEFORE AND WELL AFTER THE INDUCTION OF ENDOMETRIOSIS IS REPORTED TO INCREASE LESION SIZES IN RATS, BUT IT IS UNCLEAR WHETHER STRESS, EXPOSED SHORTLY AFTER THE INDUCTION OF ENDOMETRIOSIS, WOULD ALSO PROMOTE THE DEVELOPMENT OF ENDOMETRIOSIS, NOR IS IT CLEAR WHAT THE UNDERLYING POSSIBLE MOLECULAR MECHANISM IS. THIS STUDY WAS UNDERTAKEN TO TEST THE HYPOTHESIS THAT CHRONIC STRESS CAN PROMOTE THE DEVELOPMENT OF ENDOMETRIOSIS. A PROSPECTIVE RANDOMIZED MOUSE EXPERIMENT WAS CONDUCTED THAT SUBJECTED MICE WITH INDUCED ENDOMETRIOSIS TO PREDATOR STRESS. IN ADDITION, A CROSS-SECTIONAL IMMUNOHISTOCHEMISTRY STUDY WAS PERFORMED IN ECTOPIC AND EUTOPIC ENDOMETRIAL TISSUE SAMPLES FROM AGE- AND ROUGHLY MENSTRUAL PHASE-MATCHED WOMEN WITH OVARIAN ENDOMETRIOMAS. IT WAS FOUND THAT THE CHRONIC PSYCHOGENIC STRESS INDUCED EPIGENETIC CHANGES IN THE HIPPOCAMPUS IN MOUSE INDEPENDENT OF ENDOMETRIOSIS. IT WAS ALSO FOUND THAT CHRONIC PSYCHOGENIC STRESS INDUCED EPIGENETIC CHANGES IN THE HIPPOCAMPUS OF MICE WITH ENDOMETRIOSIS, AND SEEMINGLY ACTIVATED THE ADRENERGIC SIGNALLING IN ECTOPIC ENDOMETRIUM, RESULTING IN INCREASED ANGIOGENESIS AND ACCELERATED GROWTH OF ENDOMETRIOTIC LESIONS. THUS, CHRONIC PSYCHOGENIC STRESS PROMOTES ENDOMETRIOSIS DEVELOPMENT, RAISING THE POSSIBILITY THAT THE USE OF ANTI-DEPRESSANTS IN CASES OF PROLONGED AND INTENSE STRESS MIGHT FORESTALL THE NEGATIVE IMPACT OF STRESS ON THE DEVELOPMENT OF ENDOMETRIOSIS. 2017 10 5388 30 REDOX REGULATION OF MICRORNAS IN ENDOMETRIOSIS-ASSOCIATED PAIN. ENDOMETRIOSIS IS A CHRONIC, PAINFUL CONDITION WITH UNKNOWN ETIOLOGY. A DIFFERENTIAL EXPRESSION OF MICRORNAS IN THE ENDOMETRIOTIC TISSUES FROM WOMEN WITH ENDOMETRIOSIS WITH PAIN COMPARED TO THOSE WITHOUT SUGGESTED A PLAUSIBLE ROLE FOR MIRNA OR EPIGENETIC MECHANISMS IN THE ETIOLOGY OF ENDOMETRIOTIC PAIN. THE PERITONEAL MILIEU IS INVOLVED IN MAINTENANCE OF ENDOMETRIOTIC LESION AND NOCICEPTION. WE RECENTLY SHOWED THE MECHANISTIC ROLE FOR OXIDIZED-LIPOPROTEINS (OX-LDLS) PRESENT IN PERITONEAL FLUID (PF) IN ENDOMETRIOSIS AND PAIN. WE EXPLORED THE POSSIBILITY OF OX-LDLS MODULATING THE EXPRESSION OF MIRNAS IN A MANNER SIMILAR TO PF FROM WOMEN WITH ENDOMETRIOSIS. EXPRESSION LEVELS OF MIRNAS AND THEIR PREDICTED NOCICEPTIVE AND INFLAMMATORY TARGETS WERE DETERMINED IN PF AND OX-LDL TREATED HUMAN ENDOMETRIAL CELL-LINES. SAMPLES FROM IRB-APPROVED AND CONSENTED PATIENTS WITH AND WITHOUT ENDOMETRIOSIS OR PAIN WERE USED. THESE WERE COMPARED TO ENDOMETRIAL CELL-LINES TREATED WITH VARIOUS FORMS OF OXIDIZED-LIPOPROTEINS. RNA (INCLUDING MIRNAS) WERE ISOLATED FROM TREATED ENDOMETRIAL CELLS AND EXPRESSION LEVELS WERE DETERMINED USING COMMERCIAL MIRNOME ARRAYS. CELL LYSATES WERE USED IN IMMUNOBLOTTING FOR INFLAMMATORY PROTEINS USING A PROTEIN ARRAY. TWENTY MIRNAS INCLUDING ISOFORMS OF MIR-29, MIR-181 AND LET-7 WERE MUTUALLY DIFFERENTIALLY EXPRESSED IN CELLS TREATED WITH PF FROM ENDOMETRIOSIS PATIENTS WITH PAIN AND THOSE TREATED WITH OX-LDL COMPONENTS. THE OX-LDLS AND ENDO-PF TREATMENT ALSO PRODUCED SIGNIFICANT OVEREXPRESSION OF MICRORNA PREDICTED TARGET GENES NERVE GROWTH FACTOR, INTERLEUKIN-6 AND PROSTAGLANDIN E SYNTHASE AND OVEREXPRESSION OF THEIR DOWNSTREAM PROTEIN TARGETS MIP1ALPHA AND MCP1. THIS STUDY SHOWED SIMILARITIES BETWEEN MIRNA REGULATION IN PF FROM ENDOMETRIOTIC WOMEN AND OX-LDLS PRESENT IN ABUNDANCE IN THE PF OF THESE WOMEN. KEY MIRNAS RESPONSIBLE FOR TARGETING NOCICEPTIVE AND INFLAMMATORY MOLECULES WERE DOWNREGULATED IN THE PRESENCE OF OX-LDLS AND ENDO-PF, THUS PLAYING A ROLE IN THE ETIOLOGY OF ENDOMETRIOTIC PAIN. THESE REDOX-SENSITIVE MIRNAS CAN BE OF POTENTIAL USE AS TARGETS IN THE TREATMENT OF ENDOMETRIOSIS-ASSOCIATED PAIN. 2017 11 3047 34 GENOME-WIDE ANALYSIS OF DNA METHYLATION IN ENDOMETRIOSIS USING ILLUMINA HUMAN METHYLATION 450 K BEADCHIPS. ENDOMETRIOSIS IS A COMMON CHRONIC GYNECOLOGIC DISORDER CHARACTERIZED BY THE PRESENCE AND GROWTH OF ENDOMETRIAL-LIKE TISSUE OUTSIDE OF THE UTERINE CAVITY. ALTHOUGH THE EXACT ETIOLOGY REMAINS UNCLEAR, EPIGENETIC MODIFICATIONS, SUCH AS DNA METHYLATION, ARE THOUGHT TO CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. HERE, WE USED THE ILLUMINA HUMAN METHYLATION 450 K BEADCHIP ARRAY TO ANALYZE THE GENOME-WIDE DNA METHYLATION PROFILES OF SIX ENDOMETRIOTIC LESIONS AND SIX EUTOPIC ENDOMETRIA FROM PATIENTS WITH OVARIAN ENDOMETRIOSIS AND SIX ENDOMETRIA OF WOMEN WITHOUT ENDOMETRIOSIS. COMPARED WITH THE EUTOPIC ENDOMETRIA OF WOMEN WITH ENDOMETRIOSIS, 12,159 DIFFERENTIALLY METHYLATED CPG SITES AND 375 DIFFERENTIALLY METHYLATED PROMOTER REGIONS WERE IDENTIFIED IN ENDOMETRIOTIC LESIONS. GO ANALYSES SHOWED THAT THESE PUTATIVE DIFFERENTIALLY METHYLATED GENES WERE PRIMARILY ASSOCIATED WITH IMMUNE RESPONSE, INFLAMMATORY RESPONSE, RESPONSE TO STEROID HORMONE STIMULUS, CELL ADHESION, NEGATIVE REGULATION OF APOPTOSIS, AND ACTIVATION OF THE MAPK ACTIVITY. IN ADDITION, THE EXPRESSION LEVELS OF DNMT1, DNMT3A, DNMT3B, AND MBD2 IN ENDOMETRIOTIC LESIONS AND EUTOPIC ENDOMETRIA WERE SIGNIFICANTLY DECREASED COMPARED WITH CONTROL ENDOMETRIA. OUR FINDINGS SUGGEST THAT ABERRANT DNA METHYLATION STATUS IN ENDOMETRIOTIC LESIONS MAY PLAY A SIGNIFICANT ROLE IN THE PATHOGENESIS AND PROGRESSION OF ENDOMETRIOSIS. 2019 12 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 13 898 31 CHRONIC EXPOSURE OF MICE TO BISPHENOL-A ALTERS UTERINE FIBROBLAST GROWTH FACTOR SIGNALING AND LEADS TO ABERRANT EPITHELIAL PROLIFERATION. UTERINE EPITHELIAL PROLIFERATION IS REGULATED IN A PARACRINE MANNER BY A COMPLEX INTERPLAY BETWEEN ESTROGEN (E) AND PROGESTERONE (P) SIGNALING, IN WHICH E STIMULATES PROLIFERATION AND P INHIBITS IT. PERTURBATION OF STEROID HORMONE SIGNALING WITHIN THE UTERINE MILIEU COULD CONTRIBUTE TO THE DEVELOPMENT OF ENDOMETRIAL HYPERPLASIA AND CANCER. IT IS WELL ESTABLISHED THAT BISPHENOL-A (BPA) IS AN ENDOCRINE-DISRUPTING CHEMICAL WITH WEAK ESTROGENIC EFFECTS, ALTHOUGH LITTLE IS KNOWN ABOUT HOW IT AFFECTS STEROID HORMONE SIGNALING IN THE ADULT UTERUS. BECAUSE BPA ACTS AS A WEAK E, WE HYPOTHESIZED THAT CHRONIC EXPOSURE TO BPA WOULD CREATE AN IMBALANCE BETWEEN E AND P SIGNALING AND CAUSE CHANGES IN THE UTERUS, SUCH AS ABERRANT EPITHELIAL PROLIFERATION. INDEED, EXPOSURE TO AN ENVIRONMENTALLY RELEVANT DOSE OF BPA HAD A UTEROTROPHIC AFFECT. BPA-TREATED MICE SHOWED INCREASED PROLIFERATION, NOTABLY IN THE GLANDULAR EPITHELIUM, WHICH ARE SITES OF ORIGIN FOR ENDOMETRIAL HYPERPLASIA AND CANCER. INCREASED PROLIFERATION APPEARED TO BE MEDIATED THROUGH A SIMILAR MECHANISM AS E-INDUCED PROLIFERATION, VIA ACTIVATION OF THE FIBROBLAST GROWTH FACTOR RECEPTOR PATHWAY AND PHOSPHORYLATION OF THE ERK1/2 MITOGEN-ACTIVATED PROTEIN KINASES IN THE EPITHELIUM. INTERESTINGLY, BPA REDUCED EXPRESSION OF HEART AND NEURAL CREST DERIVATIVES EXPRESSED 2 (HAND2), A KNOWN MEDIATOR OF THE ANTIPROLIFERATIVE EFFECTS OF P. BPA ALSO INCREASED METHYLATION OF A CPG ISLAND IN THE HAND2 GENE PROMOTER, SUGGESTING THAT BPA MAY PROMOTE EPITHELIAL PROLIFERATION THROUGH EPIGENETIC SILENCING OF ANTIPROLIFERATIVE FACTORS LIKE HAND2. COLLECTIVELY, THESE FINDINGS ESTABLISH THAT CHRONIC EXPOSURE TO BPA IMPAIRS STEROID HORMONE SIGNALING IN THE MOUSE UTERUS, AND MAY CONTRIBUTE TO THE PATHOGENESIS OF UTERINE HYPERPLASIA AND CANCER. 2019 14 4310 31 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 15 2575 24 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 16 2602 36 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 17 978 31 CHRONIC OXIDATIVE STRESS CAUSES ESTROGEN-INDEPENDENT AGGRESSIVE PHENOTYPE, AND EPIGENETIC INACTIVATION OF ESTROGEN RECEPTOR ALPHA IN MCF-7 BREAST CANCER CELLS. THE ROLE OF CHRONIC OXIDATIVE STRESS IN THE DEVELOPMENT AND AGGRESSIVE GROWTH OF ESTROGEN RECEPTOR (ER)-POSITIVE BREAST CANCER IS WELL KNOWN; HOWEVER, THE MECHANISTIC UNDERSTANDING IS NOT CLEAR. ESTROGEN-INDEPENDENT GROWTH IS ONE OF THE FEATURES OF AGGRESSIVE SUBTYPE OF BREAST CANCER. THEREFORE, THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE EFFECT OF OXIDATIVE STRESS ON ESTROGEN SENSITIVITY AND EXPRESSION OF NUCLEAR ESTROGEN RECEPTORS IN ER-POSITIVE BREAST CANCER CELLS. MCF-7 CELLS CHRONICALLY EXPOSED TO HYDROGEN PEROXIDE WERE USED AS A CELL MODEL IN THIS STUDY, AND THEIR GROWTH IN RESPONSE TO 17-BETA ESTRADIOL WAS EVALUATED BY CELL VIABILITY, CELL CYCLE, AND CELL MIGRATION ANALYSIS. RESULTS WERE FURTHER CONFIRMED AT MOLECULAR LEVEL BY ANALYSIS OF GENE EXPRESSIONS AT TRANSCRIPT AND PROTEIN LEVELS. HISTONE H3 MODIFICATIONS, EXPRESSION OF EPIGENETIC REGULATORY GENES, AND THE EFFECT OF DNA DEMETHYLATION WERE ALSO ANALYZED. LOSS OF GROWTH IN RESPONSE TO ESTROGEN WITH A DECREASE IN ERALPHA EXPRESSION WAS OBSERVED IN MCF-7 CELLS ADAPTED TO CHRONIC OXIDATIVE STRESS. INCREASES IN MTTFA AND NRF1 IN THESE CELLS FURTHER SUGGESTED THE ROLE OF MITOCHONDRIA-DEPENDENT REDOX-SENSITIVE GROWTH SIGNALING AS AN ALTERNATIVE PATHWAY TO ESTROGEN-DEPENDENT GROWTH. CHANGES IN EXPRESSION OF EPIGENETIC REGULATORY GENES, LEVELS OF HISTONE H3 MODIFICATIONS AS WELL AS SIGNIFICANT RESTORATIONS OF BOTH ERALPHA EXPRESSION AND ESTROGEN RESPONSE BY 5-AZA-2'-DEOXYCYTIDINE FURTHER CONFIRMED THE EPIGENETIC BASIS FOR ESTROGEN-INDEPENDENT GROWTH IN THESE CELLS. IN CONCLUSION, RESULTS OF THIS STUDY SUGGEST THAT CHRONIC OXIDATIVE STRESS CAN CONVERT ESTROGEN-DEPENDENT NONAGGRESSIVE BREAST CANCER CELLS INTO ESTROGEN-INDEPENDENT AGGRESSIVE FORM POTENTIALLY BY EPIGENETIC MECHANISM. 2015 18 2669 38 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 19 3726 25 INHIBITION OF HISTONE METHYLTRANSFERASE EZH2 SUPPRESSES ENDOMETRIOTIC VESICLE DEVELOPMENT IN A RAT MODEL OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A PAINFUL GYNECOLOGICAL DISEASE WITH NO CURE AND LIMITED THERAPEUTIC OPTIONS. IT HAS BEEN HYPOTHESIZED THAT EPIGENETIC DRUGS CAN BE USED AS A NONHORMONAL TREATMENT FOR ENDOMETRIOSIS. THIS STUDY WAS CONDUCTED TO STUDY THE EFFICACY OF AN INHIBITOR OF THE HISTONE METHYLTRANSFERASE EZH2 USING AN ESTABLISHED RAT MODEL OF ENDOMETRIOSIS. WE HYPOTHESIZED THAT TREATMENT WILL BLOCK OR REDUCE THE NUMBER OF ENDOMETRIOTIC VESICLES IN THIS MODEL. WE CONDUCTED A PRECLINICAL DRUG STUDY IN FEMALE RATS WITH EXPERIMENTAL ENDOMETRIOSIS (UTERINE TISSUE TRANSPLANTED NEXT TO THE INTESTINAL MESENTERY) OR CONTROL SHAM (SUTURES ONLY). RATS WITH ENDOMETRIOSIS OR SHAM SURGERY RECEIVED EITHER TREATMENT WITH EZH2 INHIBITOR (5 MG/KG OR 10 MG/KG) OR VEHICLE (0.1%, 67% DMSO) EVERY OTHER DAY DURING 4 WEEKS. AFTER TREATMENT COMPLETION, THE NUMBER, AREA, VOLUME, AND WEIGHT OF VESICLES WERE EVALUATED. RT [2] PROFILER ARRAYS FOR NEUROPATHIC AND INFLAMMATION, EPITHELIAL TO MESENCHYMAL TRANSITION, INFLAMMATORY RESPONSE, AND AUTOIMMUNITY PATHWAYS WERE USED TO EXAMINE GENE EXPRESSION CHANGES IN THE VESICLES THAT DEVELOPED. TREATMENT WITH EZH2 INHIBITOR (10 MG/KG) SUPPRESSED THE DEVELOPMENT OF VESICLES, BY SIGNIFICANTLY DECREASING THE TOTAL VESICLE NUMBER, AREA, VOLUME, AND WEIGHT. IN ADDITION, EZH2 INHIBITION SIGNIFICANTLY INCREASED THE EXPRESSION OF CACNA1B AND FKBP1A GENES, INVOLVED IN PAIN AND PROLIFERATION, RESPECTIVELY. EZH2 INHIBITION SUPPRESSES THE GROWTH OF VESICLES WITHOUT APPARENT DETRIMENTAL EFFECTS TO OTHER ORGANS. TREATMENT WITH THIS EPIGENETIC INHIBITOR LEADS TO UPREGULATION OF A LIMITED NUMBER OF GENES RELATED TO ENDOMETRIOSIS-RELEVANT PATHWAYS. IN CONCLUSION, THESE DATA SUPPORT FOLLOW-UP STUDIES TO EVALUATE ITS POTENTIAL AS A THERAPEUTIC APPROACH FOR ENDOMETRIOSIS. 2020 20 5241 28 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