1 3174 150 H19 LNCRNA IDENTIFIED AS A MASTER REGULATOR OF GENES THAT DRIVE UTERINE LEIOMYOMAS. UTERINE LEIOMYOMAS OR FIBROIDS (UFS) ARE BENIGN TUMORS CHARACTERIZED BY HYPERPLASTIC SMOOTH MUSCLE CELLS AND EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX (ECM). AFFLICTING ~80% OF WOMEN, AND SYMPTOMATIC IN 25%, UFS BRING TREMENDOUS SUFFERING AND ARE AN ECONOMIC BURDEN WORLDWIDE; THEY CAUSE SEVERE PAIN AND BLEEDING, AND ARE THE LEADING CAUSE OF HYSTERECTOMY. YET, UFS ARE SEVERELY UNDERSTUDIED WITH FEW EFFECTIVE TREATMENT OPTIONS AVAILABLE; THOSE THAT ARE AVAILABLE FREQUENTLY HAVE SIGNIFICANT SIDE EFFECTS SUCH AS MENOPAUSAL SYMPTOMS. RECENTLY, INTEGRATED GENOME-SCALE STUDIES HAVE REVEALED MUTATIONS AND FIBROID SUBTYPE-SPECIFIC EXPRESSION CHANGES IN KEY DRIVER GENES, WITH MED12 AND HMGA2 TOGETHER CONTRIBUTING TO NEARLY 90% OF ALL UFS, BUT THEIR REGULATION OF EXPRESSION IS POORLY CHARACTERIZED. HERE WE REPORT THAT THE EXPRESSION OF H19 LONG NONCODING RNA (LNCRNA) IS ABERRANTLY INCREASED IN UFS. USING CELL CULTURE AND GENOME-WIDE TRANSCRIPTOME AND METHYLATION PROFILING ANALYSES, WE DEMONSTRATE THAT H19 PROMOTES EXPRESSION OF MED12, HMGA2, AND KEY ECM-REMODELING GENES VIA MULTIPLE MECHANISMS INCLUDING A NEW CLASS OF EPIGENETIC MODIFICATION BY TET3. OUR RESULTS MARK THE FIRST EXAMPLE OF AN EVOLUTIONARILY CONSERVED LNCRNA IN PATHOGENESIS OF UFS AND REGULATION OF TET EXPRESSION. GIVEN THE LINK BETWEEN A H19 SINGLE-NUCLEOTIDE POLYMORPHISM (SNP) AND INCREASED RISK AND TUMOR SIZE OF UFS, AND THE EXISTENCE OF MULTIPLE FIBROID SUBTYPES DRIVEN BY KEY PATHWAY GENES REGULATED BY H19, WE PROPOSE A UNIFYING MECHANISM FOR PATHOGENESIS OF UTERINE FIBROIDS MEDIATED BY H19 AND IDENTIFY A PATHWAY FOR FUTURE EXPLORATION OF NOVEL TARGET THERAPIES FOR UTERINE LEIOMYOMAS. 2019 2 2295 37 EPIGENETIC REGULATION IN UTERINE FIBROIDS-THE ROLE OF TEN-ELEVEN TRANSLOCATION ENZYMES AND THEIR POTENTIAL THERAPEUTIC APPLICATION. UTERINE FIBROIDS (UFS) ARE MONOCLONAL, BENIGN TUMORS THAT CONTAIN ABNORMAL SMOOTH MUSCLE CELLS AND THE ACCUMULATION OF EXTRACELLULAR MATRIX (ECM). ALTHOUGH BENIGN, UFS ARE A MAJOR SOURCE OF GYNECOLOGIC AND REPRODUCTIVE DYSFUNCTION, RANGING FROM MENORRHAGIA AND PELVIC PAIN TO INFERTILITY, RECURRENT MISCARRIAGE, AND PRETERM LABOR. MANY RISK FACTORS ARE INVOLVED IN THE PATHOGENESIS OF UFS VIA GENETIC AND EPIGENETIC MECHANISMS. THE LATTER INVOLVING DNA METHYLATION AND DEMETHYLATION REACTIONS PROVIDE SPECIFIC DNA METHYLATION PATTERNS THAT REGULATE GENE EXPRESSION. ACTIVE DNA DEMETHYLATION REACTIONS MEDIATED BY TEN-ELEVEN TRANSLOCATION PROTEINS (TETS) AND ELEVATED LEVELS OF 5-HYDROXYMETHYLCYTOSINE HAVE BEEN SUGGESTED TO BE INVOLVED IN UF FORMATION. THIS REVIEW PAPER SUMMARIZES THE MAIN FINDINGS REGARDING THE FUNCTION OF TET ENZYMES AND THEIR ACTIVITY DYSREGULATION THAT MAY TRIGGER THE DEVELOPMENT OF UFS. UNDERSTANDING THE ROLE THAT EPIGENETICS PLAYS IN THE PATHOGENESIS OF UFS MAY POSSIBLY LEAD TO A NEW TYPE OF PHARMACOLOGICAL FERTILITY-SPARING TREATMENT METHOD. 2022 3 1744 50 EARLY LIFE ADVERSE ENVIRONMENTAL EXPOSURES INCREASE THE RISK OF UTERINE FIBROID DEVELOPMENT: ROLE OF EPIGENETIC REGULATION. UTERINE FIBROIDS [UF(S), AKA: LEIOMYOMA] ARE THE MOST IMPORTANT BENIGN NEOPLASTIC THREAT TO WOMEN'S HEALTH. THEY ARE THE MOST COMMON CAUSE OF HYSTERECTOMY IMPOSING UNTOLD PERSONAL CONSEQUENCES AND 100S OF BILLIONS OF HEALTHCARE DOLLARS, WORLDWIDE. CURRENTLY, THERE IS NO LONG TERM EFFECTIVE FDA-APPROVED MEDICAL TREATMENT AVAILABLE, AND SURGERY IS THE MAINSTAY. THE ETIOLOGY OF UFS IS NOT FULLY UNDERSTOOD. IN THIS REGARD, WE AND OTHERS HAVE RECENTLY REPORTED THAT SOMATIC MUTATIONS IN THE GENE ENCODING THE TRANSCRIPTIONAL MEDIATOR SUBUNIT MED12 ARE FOUND TO OCCUR AT A HIGH FREQUENCY ( APPROXIMATELY 85%) IN UFS. UFS LIKELY ORIGINATE WHEN A MED12 MUTATION OCCURS IN A MYOMETRIAL STEM CELL CONVERTING IT INTO A TUMOR-FORMING STEM CELL LEADING TO A CLONAL FIBROID LESION. ALTHOUGH THE MOLECULAR ATTRIBUTES UNDERLYING THE MECHANISTIC FORMATION OF UFS IS LARGELY UNKNOWN, A GROWING BODY OF LITERATURE IMPLICATES UNFAVORABLE EARLY LIFE ENVIRONMENTAL EXPOSURES AS POTENTIALLY IMPORTANT CONTRIBUTORS. EARLY LIFE EXPOSURE TO EDCS DURING SENSITIVE WINDOWS OF DEVELOPMENT CAN REPROGRAM NORMAL PHYSIOLOGICAL RESPONSES AND ALTER DISEASE SUSCEPTIBILITY LATER IN LIFE. NEONATAL EXPOSURE TO THE EDCS SUCH AS DIETHYLSTILBESTROL (DES) AND GENISTEIN DURING REPRODUCTIVE TRACT DEVELOPMENT HAS BEEN SHOWN TO INCREASE THE INCIDENCE, MULTIPLICITY AND OVERALL SIZE OF UFS IN THE EKER RAT MODEL, CONCOMITANTLY REPROGRAMMING ESTROGEN-RESPONSIVE GENE EXPRESSION. IMPORTANTLY, EDC EXPOSURE REPRESSES ENHANCER OF ZESTE 2 (EZH2) AND REDUCES LEVELS OF HISTONE 3 LYSINE 27 TRIMETHYLATION (H3K27ME3) REPRESSIVE MARK THROUGH ESTROGEN RECEPTOR/PHOSPHATIDYLINOSITIDE 3-KINASES/PROTEIN KINASE B NON-GENOMIC SIGNALING IN THE DEVELOPING UTERUS. CONSIDERING THE FACT THAT DISTINCT MEDIATOR COMPLEX SUBUNIT 12 (MED12) MUTATIONS ARE DETECTED IN DIFFERENT FIBROID LESIONS IN THE SAME UTERUS, THE EMERGENCE OF EACH MED12 MUTATION IS LIKELY AN INDEPENDENT EVENT IN AN ALTERED MYOMETRIAL STEM CELL. IT IS THEREFORE POSSIBLE THAT A CHRONIC REDUCTION IN DNA REPAIR CAPACITY EVENTUALLY CAUSES THE EMERGENCE OF MUTATIONS SUCH AS MED12 IN MYOMETRIAL STEM CELLS CONVERTING THEM INTO FIBROID TUMOR-FORMING STEM CELLS, AND THEREBY LEADS TO THE DEVELOPMENT OF UFS. ADVANCING OUR UNDERSTANDING OF THE MECHANISTIC ROLE EPIGENETIC REGULATION OF STEM CELLS PLAYS IN MEDIATING RISK AND TUMORIGENESIS WILL HELP IN POINTING THE WAY TOWARD THE DEVELOPMENT OF NOVEL THERAPEUTIC OPTIONS. 2016 4 828 49 CHARACTERIZATION OF M (6) A MODIFIERS AND RNA MODIFICATIONS IN UTERINE FIBROIDS. UTERINE LEIOMYOMA OR FIBROIDS ARE THE MOST COMMON PREVALENT NONCANCEROUS TUMORS OF THE UTERINE MUSCLE LAYER. COMMON SYMPTOMS ASSOCIATED WITH FIBROIDS INCLUDE PELVIC PAIN, HEAVY MENSTRUAL BLEEDING, ANEMIA, AND PELVIC PRESSURE. THESE TUMORS ARE A LEADING CAUSE OF GYNECOLOGICAL CARE BUT LACK LONG-TERM THERAPY AS THE ORIGIN AND DEVELOPMENT OF FIBROIDS ARE NOT WELL UNDERSTOOD. SEVERAL NEXT-GENERATION SEQUENCING TECHNOLOGIES HAVE BEEN PERFORMED TO IDENTIFY THE UNDERLYING GENETIC AND EPIGENETIC BASIS OF FIBROIDS. HOWEVER, THERE REMAINS A SYSTEMIC GAP IN OUR UNDERSTANDING OF MOLECULAR AND BIOLOGICAL PROCESS THAT DEFINE UTERINE FIBROIDS. RECENT EPITRANSCRIPTOMICS STUDIES HAVE UNRAVELED RNA MODIFICATIONS THAT ARE ASSOCIATED WITH ALL FORMS OF RNA AND ARE THOUGHT TO INFLUENCE BOTH NORMAL PHYSIOLOGICAL FUNCTIONS AND THE PROGRESSION OF DISEASES. WE QUANTIFIED RNA EXPRESSION PROFILES BY ANALYZING PUBLICLY AVAILABLE RNA-SEQ DATA FOR 15 KNOWN EPIGENETIC MEDIATORS TO IDENTIFY THEIR EXPRESSION PROFILE IN UTERINE FIBROIDS COMPARED TO MYOMETRIUM. TO VALIDATE OUR FINDINGS, WE PERFORMED RT-QPCR ON A SEPARATE COHORT OF UTERINE FIBROIDS TARGETING THESE MODIFIERS CONFIRMING OUR RNA-SEQ DATA. WE THEN EXAMINED PROTEIN PROFILES OF KEY M (6) A MODIFIERS IN FIBROIDS AND THEIR MATCHED MYOMETRIUM. IN CONCORDANCE WITH OUR RNA EXPRESSION PROFILES, NO SIGNIFICANT DIFFERENCES WERE OBSERVED IN THESE PROTEINS IN UTERINE FIBROIDS COMPARED TO MYOMETRIUM. TO DETERMINE ABUNDANCE OF RNA MODIFICATIONS, MRNA AND SMALL RNA FROM FIBROIDS AND MATCHED MYOMETRIUM WERE ANALYZED BY UHPLC MS/MS. IN ADDITION TO THE PREVALENT N6-METHYLADENOSINE (M (6) A), WE IDENTIFIED 11 OTHER KNOWN MODIFIERS BUT DID NOT IDENTIFY ANY ABERRANT EXPRESSION IN FIBROIDS. WE THEN MINED A PREVIOUSLY PUBLISHED DATASET AND IDENTIFIED DIFFERENTIAL EXPRESSION OF M (6) A MODIFIERS THAT WERE SPECIFIC TO FIBROID GENETIC SUB-TYPE. OUR ANALYSIS ALSO IDENTIFIED M (6) A CONSENSUS MOTIFS ON GENES PREVIOUSLY IDENTIFIED TO BE DYSREGULATED IN UTERINE FIBROIDS. OVERALL, USING STATE-OF-THE-ART MASS SPECTROMETRY, RNA EXPRESSION AND PROTEIN PROFILES, WE CHARACTERIZED AND IDENTIFIED DIFFERENTIALLY EXPRESSED M (6) A MODIFIERS IN RELATION TO DRIVER MUTATIONS. DESPITE THE USE OF SEVERAL DIFFERENT APPROACHES, WE IDENTIFIED LIMITED DIFFERENTIAL EXPRESSION OF RNA MODIFIERS AND ASSOCIATED MODIFICATIONS IN UTERINE FIBROIDS. HOWEVER, CONSIDERING THE HIGHLY HETEROGENOUS GENOMIC AND CELLULAR NATURE OF FIBROIDS, AND THE POSSIBLE CONTRIBUTION OF SINGLE MOLECULE M (6) A MODIFICATIONS TO FIBROID PATHOLOGY, THERE IS A NEED FOR GREATER IN-DEPTH CHARACTERIZATION OF M (6) A MARKS AND MODIFIERS IN A LARGER AND VARIED PATIENT COHORT. 2023 5 4413 40 MOLECULAR AND CELLULAR INSIGHTS INTO THE DEVELOPMENT OF UTERINE FIBROIDS. UTERINE LEIOMYOMAS REPRESENT THE MOST COMMON BENIGN GYNECOLOGIC TUMOR. THESE HORMONE-DEPENDENT SMOOTH-MUSCLE FORMATIONS OCCUR WITH AN ESTIMATED PREVALENCE OF ~70% AMONG WOMEN OF REPRODUCTIVE AGE AND CAUSE SYMPTOMS INCLUDING PAIN, ABNORMAL UTERINE BLEEDING, INFERTILITY, AND RECURRENT ABORTION. DESPITE THE PREVALENCE AND PUBLIC HEALTH IMPACT OF UTERINE LEIOMYOMAS, AVAILABLE TREATMENTS REMAIN LIMITED. AMONG THE POTENTIAL CAUSES OF LEIOMYOMAS, EARLY HORMONAL EXPOSURE DURING PERIODS OF DEVELOPMENT MAY RESULT IN DEVELOPMENTAL REPROGRAMMING VIA EPIGENETIC CHANGES THAT PERSIST IN ADULTHOOD, LEADING TO DISEASE ONSET OR PROGRESSION. RECENT DEVELOPMENTS IN UNBIASED HIGH-THROUGHPUT SEQUENCING TECHNOLOGY ENABLE POWERFUL APPROACHES TO DETECT DRIVER MUTATIONS, YIELDING NEW INSIGHTS INTO THE GENOMIC INSTABILITY OF LEIOMYOMAS. CURRENT DATA ALSO SUGGEST THAT EACH LEIOMYOMA ORIGINATES FROM THE CLONAL EXPANSION OF A SINGLE TRANSFORMED SOMATIC STEM CELL OF THE MYOMETRIUM. IN THIS REVIEW, WE PROPOSE AN INTEGRATED CELLULAR AND MOLECULAR VIEW OF THE ORIGINS OF LEIOMYOMAS, AS WELL AS PARADIGM-SHIFTING STUDIES THAT WILL LEAD TO BETTER UNDERSTANDING AND THE FUTURE DEVELOPMENT OF NON-SURGICAL TREATMENTS FOR THESE HIGHLY FREQUENT TUMORS. 2021 6 1202 33 COULD DNA HYDROXYMETHYLATION BE CRUCIAL IN INFLUENCING STEROID HORMONE SIGNALING IN ENDOMETRIAL BIOLOGY AND ENDOMETRIOSIS? ENDOMETRIOSIS AFFECTS 10% OF REPRODUCTIVE-AGED WOMEN. IT IS CHARACTERIZED BY THE GROWTH OF THE ENDOMETRIUM, OUTSIDE THE UTERUS AND IS ASSOCIATED WITH INFERTILITY AND CHRONIC ABDOMINAL PAIN. LACK OF NONINVASIVE DIAGNOSTIC TOOLS AND EARLY SCREENING TESTS RESULTS IN DELAYED TREATMENT AND SUBSEQUENTLY INCREASED DISEASE SEVERITY. ENDOMETRIOSIS IS A DISEASE ASSOCIATED WITH A DEREGULATED HORMONAL RESPONSE, THEREFORE, UNDERSTANDING THE MOLECULAR MECHANISMS THAT GOVERN THIS HORMONAL INTERPLAY IS OF PARAMOUNT IMPORTANCE. DNA METHYLATION IS AN EPIGENETIC MARK THAT REGULATES GENE EXPRESSION AND IS OFTEN ASSOCIATED WITH GENES THAT CODE FOR STEROID RECEPTORS AND ENZYMES ASSOCIATED WITH ESTROGEN SYNTHESIS AND METABOLISM IN ENDOMETRIOSIS. DNA HYDROXYMETHYLATION, WHICH IS STRUCTURALLY SIMILAR TO METHYLATION BUT FUNCTIONALLY DIFFERENT, IS A BIOLOGICALLY CRITICAL MECHANISM THAT IS ALSO KNOWN TO REGULATE GENE EXPRESSION. TEN ELEVEN TRANSLOCATION (TET) PROTEINS MEDIATE HYDROXYMETHYLATION. HOWEVER, THE ROLE OF DNA HYDROXYMETHYLATION OR TETS IN THE ENDOMETRIUM REMAINS RELATIVELY UNEXPLORED. CURRENTLY, THE "GOLD STANDARD" TECHNIQUE USED TO STUDY METHYLATION PATTERNS IS BISULFITE GENOMIC SEQUENCING. THIS TECHNIQUE ALSO DETECTS HYDROXYMETHYLATION BUT FAILS TO DISTINGUISH BETWEEN THE TWO, THEREBY LIMITING OUR UNDERSTANDING OF THESE TWO PROCESSES. THE PRESENCE OF TETS IN THE MALE AND FEMALE REPRODUCTIVE TRACT AND ITS CONTRIBUTION TO ENDOMETRIAL CANCER MAKES IT AN IMPORTANT FACTOR TO STUDY IN ENDOMETRIOSIS. THIS REVIEW SUMMARIZES THE ROLE OF DNA METHYLATION IN ABERRANT STEROID HORMONE SIGNALING AND HYPOTHESIZES THAT HYDROXYMETHYLATION COULD BE A FACTOR INFLUENCING HORMONAL INSTABILITY SEEN IN ENDOMETRIOSIS. 2020 7 3005 32 GENETIC, EPIGENETIC, AND STEROIDOGENIC MODULATION MECHANISMS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC GYNECOLOGICAL DISEASE, AFFECTING UP TO 10% OF REPRODUCTIVE-AGE WOMEN. THE EXACT CAUSE OF THE DISEASE IS UNKNOWN; HOWEVER, IT IS A HERITABLE CONDITION AFFECTED BY MULTIPLE GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. PREVIOUS STUDIES REPORTED VARIATIONS IN THE EPIGENETIC PATTERNS OF NUMEROUS GENES KNOWN TO BE INVOLVED IN THE ABERRANT MODULATION OF CELL CYCLE STEROIDOGENESIS, ABNORMAL HORMONAL, IMMUNE AND INFLAMMATORY STATUS IN ENDOMETRIOSIS, APOPTOSIS, ADHESION, ANGIOGENESIS, PROLIFERATION, IMMUNE AND INFLAMMATORY PROCESSES, RESPONSE TO HYPOXIA, STEROIDOGENIC PATHWAY AND HORMONE SIGNALING ARE INVOLVED IN THE PATHOGENESIS OF ENDOMETRIOSIS. ACCUMULATING EVIDENCE SUGGEST THAT VARIOUS EPIGENETIC ABERRATIONS MAY CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. AMONG THEM, DNA METHYLTRANSFERASES, HISTONE DEACETYLATORS, AND NON-CODING MICRORNAS DEMONSTRATE DIFFERENTIAL EXPRESSION WITHIN ENDOMETRIOTIC LESIONS AND IN THE ENDOMETRIUM OF PATIENTS WITH ENDOMETRIOSIS. IT HAS BEEN INDICATED THAT THE IDENTIFICATION OF EPIGENETIC DIFFERENCES WITHIN THE DNA OR HISTONE PROTEINS MAY CONTRIBUTE TO THE DISCOVERY OF A USEFUL PROGNOSTIC BIOMARKER, WHICH COULD AID IN THE FUTURE EARLIER DETECTION, TIMELY DIAGNOSIS, AND INITIATION OF A NEW APPROACH TO THE TREATMENT OF ENDOMETRIOSIS, AS WELL AS INFORM US ABOUT THE EFFECTIVENESS OF TREATMENT AND THE STAGE OF THE DISEASE. AS THE ETIOLOGY OF ENDOMETRIOSIS IS HIGHLY COMPLEX AND STILL FAR FROM BEING FULLY ELUCIDATED, THE PRESENTED REVIEW FOCUSES ON DIFFERENT APPROACHES TO IDENTIFY THE GENETIC AND EPIGENETIC LINKS OF ENDOMETRIOSIS AND ITS PATHOGENESIS. 2020 8 3003 44 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 9 1028 31 CIRCULATING MIRNAS RELATED TO EPITHELIAL-MESENCHYMAL TRANSITIONS (EMT) AS THE NEW MOLECULAR MARKERS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC GYNECOLOGICAL DISEASE DEFINED BY THE PRESENCE OF ENDOMETRIAL-LIKE TISSUE FOUND OUTSIDE THE UTERUS, MOST COMMONLY IN THE PERITONEAL CAVITY. ENDOMETRIOSIS LESIONS ARE HETEROGENOUS BUT USUALLY CONTAIN ENDOMETRIAL STROMAL CELLS AND EPITHELIAL GLANDS, IMMUNE CELL INFILTRATES AND ARE VASCULARIZED AND INNERVATED BY NERVES. THE COMPLEX ETIOPATHOGENESIS AND HETEROGENITY OF THE CLINICAL SYMPTOMS, AS WELL AS THE LACK OF A SPECIFIC NON-INVASIVE DIAGNOSTIC BIOMARKERS, UNDERLINE THE NEED FOR MORE ADVANCED DIAGNOSTIC TOOLS. UNFORTUNATELY, THE CONTRIBUTION OF ENVIRONMENTAL, HORMONAL AND IMMUNOLOGICAL FACTORS IN THE DISEASE ETIOLOGY IS INSUFFICIENT, AND THE CONTRIBUTION OF GENETIC/EPIGENETIC FACTORS IS STILL FRAGMENTARY. THEREFORE, THERE IS A NEED FOR MORE FOCUSED STUDY ON THE MOLECULAR MECHANISMS OF ENDOMETRIOSIS AND NON-INVASIVE DIAGNOSTIC MONITORING SYSTEMS. MICRORNAS (MIRNAS) DEMONSTRATE HIGH STABILITY AND TISSUE SPECIFICITY AND PLAY A SIGNIFICANT ROLE IN MODULATING A RANGE OF MOLECULAR PATHWAYS, AND HENCE MAY BE SUITABLE DIAGNOSTIC BIOMARKERS FOR THE ORIGIN AND DEVELOPMENT OF ENDOMETRIOSIS. OF THESE, THE MOST FREQUENTLY STUDIED ARE THOSE RELATED TO ENDOMETRIOSIS, INCLUDING THOSE INVOLVED IN EPITHELIAL-MESENCHYMAL TRANSITION (EMT), WHOSE EXPRESSION IS ALTERED IN PLASMA OR ENDOMETRIOTIC LESION BIOPSIES; HOWEVER, THE RESULTS ARE AMBIGUOUS. SPECIFIC MIRNAS EXPRESSED IN ENDOMETRIOSIS MAY SERVE AS DIAGNOSTICS MARKERS WITH PROGNOSTIC VALUE, AND THEY HAVE BEEN PROPOSED AS MOLECULAR TARGETS FOR TREATMENT. THE AIM OF THIS REVIEW IS TO PRESENT SELECTED MIRNAS ASSOCIATED WITH EMT KNOWN TO HAVE EXPERIMENTALLY CONFIRMED SIGNIFICANCE, AND DISCUSS THEIR UTILITY AS BIOMARKERS IN ENDOMETRIOSIS. 2021 10 1269 40 CYTOSINE METHYLATION CHANGES IN ENHANCER REGIONS OF CORE PRO-FIBROTIC GENES CHARACTERIZE KIDNEY FIBROSIS DEVELOPMENT. BACKGROUND: ONE IN ELEVEN PEOPLE IS AFFECTED BY CHRONIC KIDNEY DISEASE, A CONDITION CHARACTERIZED BY KIDNEY FIBROSIS AND PROGRESSIVE LOSS OF KIDNEY FUNCTION. EPIDEMIOLOGICAL STUDIES INDICATE THAT ADVERSE INTRAUTERINE AND POSTNATAL ENVIRONMENTS HAVE A LONG-LASTING ROLE IN CHRONIC KIDNEY DISEASE DEVELOPMENT. EPIGENETIC INFORMATION REPRESENTS A PLAUSIBLE CARRIER FOR MEDIATING THIS PROGRAMMING EFFECT. HERE WE DEMONSTRATE THAT GENOME-WIDE CYTOSINE METHYLATION PATTERNS OF HEALTHY AND CHRONIC KIDNEY DISEASE TUBULE SAMPLES OBTAINED FROM PATIENTS SHOW SIGNIFICANT DIFFERENCES. RESULTS: WE IDENTIFY DIFFERENTIALLY METHYLATED REGIONS AND VALIDATE THESE IN A LARGE REPLICATION DATASET. THE DIFFERENTIALLY METHYLATED REGIONS ARE RARELY OBSERVED ON PROMOTERS, BUT MOSTLY OVERLAP WITH PUTATIVE ENHANCER REGIONS, AND THEY ARE ENRICHED IN CONSENSUS BINDING SEQUENCES FOR IMPORTANT RENAL TRANSCRIPTION FACTORS. THIS INDICATES THEIR IMPORTANCE IN GENE EXPRESSION REGULATION. A CORE SET OF GENES THAT ARE KNOWN TO BE RELATED TO KIDNEY FIBROSIS, INCLUDING GENES ENCODING COLLAGENS, SHOW CYTOSINE METHYLATION CHANGES CORRELATING WITH DOWNSTREAM TRANSCRIPT LEVELS. CONCLUSIONS: OUR REPORT RAISES THE POSSIBILITY THAT EPIGENETIC DYSREGULATION PLAYS A ROLE IN CHRONIC KIDNEY DISEASE DEVELOPMENT VIA INFLUENCING CORE PRO-FIBROTIC PATHWAYS AND CAN AID THE DEVELOPMENT OF NOVEL BIOMARKERS AND FUTURE THERAPEUTICS. 2013 11 6428 33 THE TUMOR MICROENVIRONMENT AND METASTATIC DISEASE. THE MICROENVIRONMENT OF SOLID TUMORS IS A HETEROGENEOUS, COMPLEX MILIEU FOR TUMOR GROWTH AND SURVIVAL THAT INCLUDES FEATURES SUCH AS ACIDIC PH, LOW NUTRIENT LEVELS, ELEVATED INTERSTITIAL FLUID PRESSURE (IFP) AND CHRONIC AND FLUCTUATING LEVELS OF OXYGENATION THAT RELATE TO THE ABNORMAL VASCULAR NETWORK THAT EXISTS IN TUMORS. THE METASTATIC POTENTIAL OF TUMOR CELLS IS BELIEVED TO BE REGULATED BY INTERACTIONS BETWEEN THE TUMOR CELLS AND THEIR EXTRACELLULAR ENVIRONMENT (EXTRACELLULAR MATRIX (ECM)). THESE INTERACTIONS CAN BE MODIFIED BY THE ACCUMULATION OF GENETIC CHANGES AND BY THE TRANSIENT ALTERATIONS IN GENE EXPRESSION INDUCED BY THE LOCAL TUMOR MICROENVIRONMENT. CLINICAL AND EXPERIMENTAL EVIDENCE SUGGESTS THAT ALTERED GENE EXPRESSION IN RESPONSE TO THE HYPOXIC MICROENVIRONMENT IS A CONTRIBUTING FACTOR TO INCREASED METASTATIC EFFICIENCY. A NUMBER OF GENES THAT HAVE BEEN IMPLICATED IN THE METASTATIC PROCESS, INVOLVING ANGIOGENESIS, INTRA/EXTRAVASATION, SURVIVAL AND GROWTH, HAVE BEEN FOUND TO BE HYPOXIA-RESPONSIVE. THE VARIOUS METASTATIC DETERMINANTS, GENETIC AND EPIGENETIC, SOMATIC AND INHERITED MAY SERVE AS PRECEDENTS FOR THE FUTURE IDENTIFICATION OF MORE GENES THAT ARE INVOLVED IN METASTASIS. MUCH RESEARCH HAS FOCUSED ON GENETIC AND MOLECULAR PROPERTIES OF THE TUMOR CELLS THEMSELVES. IN THE PRESENT REVIEW WE DISCUSS THE EPIGENETIC AND PHYSIOLOGICAL REGULATION OF METASTASIS AND EMPHASIZE THE NEED FOR FURTHER STUDIES ON THE INTERACTIONS BETWEEN THE PATHOPHYSIOLOGIC TUMOR MICROENVIRONMENT AND THE TUMOR EXTRACELLULAR MATRIX. 2009 12 5892 37 SYSTEMS GENETICS VIEW OF ENDOMETRIOSIS: A COMMON COMPLEX DISORDER. ENDOMETRIOSIS IS A CONDITION IN WHICH CELLS DERIVED FROM THE ENDOMETRIUM GROW OUTSIDE THE UTERUS, E.G. IN THE PERITONEUM (EXTERNAL GENITAL ENDOMETRIOSIS). AS THESE CELLS ARE UNDER THE INFLUENCE OF FEMALE HORMONES, MAJOR SYMPTOMS OF ENDOMETRIOSIS ARE PAIN, ESPECIALLY DURING THE CYCLE, AND INFERTILITY. NUMEROUS HYPOTHESES FOR THE FORMATION OF ENDOMETRIOSIS CAN BE FOUND IN THE LITERATURE, BUT THERE IS GROWING EVIDENCE OF SERIOUS GENETIC CONTRIBUTIONS TO ENDOMETRIOSIS SUSCEPTIBILITY. THE INVOLVEMENT OF GENES, STEROID HORMONE METABOLISM, IMMUNOLOGICAL REACTIONS, RECEPTOR FORMATION, INFLAMMATION, PROLIFERATION, APOPTOSIS, INTERCELLULAR ADHESION, CELL INVASION AND ANGIOGENESIS AS WELL AS GENES REGULATING THE ACTIVITY OF AFOREMENTIONED ENZYMES HAVE BEEN SUGGESTED. SOME MORE RECENTLY SUGGESTED CANDIDATE GENES PICKED UP IN GENOME-WIDE ASSOCIATION STUDIES ARE INVOLVED IN ONCOGENESIS, METAPLASIA OF ENDOMETRIUM CELLS AND PATHWAYS OF EMBRYONIC DEVELOPMENT OF THE FEMALE REPRODUCTIVE SYSTEM. HOWEVER, GENE MUTATIONS PROVEN TO BE CAUSATIVE FOR ENDOMETRIOSIS HAVE NOT BEEN IDENTIFIED SO FAR, EVEN THOUGH THE ABNORMAL EXPRESSION OF CANDIDATE GENES FOR ENDOMETRIOSIS COULD BE PROVOKED BY DIFFERENT EPIGENETIC MODIFICATIONS INCLUDING DNA METHYLATION, HETEROCHROMATIZATION OR INTRODUCTION OF REGULATORY MIRNA. WE HYPOTHESIZE THAT ENDOMETRIOSIS IS INDUCED BY A COMBINATION OF ABNORMAL GENETIC AND/OR EPIGENETIC MUTATIONS: THE LATTER PAVE THE WAY FOR PATHOLOGICAL CHANGES WHICH BECOME IRREVERSIBLE, AND ACCORDING TO THE "EPIGENETIC LANDSCAPE" THEORY, THIS PROCEEDS TO THE TYPICAL CLINICAL MANIFESTATIONS. TWO STAGES IN THE ENDOMETRIOSIS PATHWAY ARE SUGGESTED: (1) INDUCTION OF PRIMARY ENDOMETRIAL CELLS TOWARD ENDOMETRIOSIS, AND (2) IMPLANTATION AND PROGRESSION OF THESE CELLS INTO ENDOMETRIOSIS LESIONS. THE MODEL FAVORS ENDOMETRIOSIS AS AN OUTGROWTH OF PRIMARY CELLS DIFFERENT IN THEIR ORIGIN, CANALIZATION OF PATHOLOGICAL PROCESSES, MANIFESTATION DIVERSITY PROVOKED BY UNIQUE GENETIC BACKGROUND AND EPIGENETIC INFLUENCES, WHICH RESULT IN MANY DIFFERENT CLINICAL FORMS OF THE DISEASE. 2015 13 4228 26 METHYLATION OF INFLAMMATORY CELLS IN LUNG DISEASES. THIS CHAPTER OVERVIEWS ROLES OF DNA METHYLATION IN INFLAMMATORY CELL BIOLOGY WITH THE FOCUSES ON LYMPHOCYTES AND MACROPHAGES/MONOCYTES IN LUNG DISEASES, ALTHOUGH THE MOLECULAR MECHANISMS BY WHICH TARGET GENES ARE METHYLATED AND REGULATED IN LUNG DISEASES REMAIN UNCLEAR. MOST OF EPIGENETIC STUDIES ON DNA METHYLATION OF TARGET GENES IN LUNG DISEASES MAINLY DEMONSTRATED THE CORRELATION OF DNA METHYLATION OF TARGET GENES WITH THE LEVELS OF OTHER CORRESPONDING FACTORS, WITH THE SPECIFICITY OF CLINICAL PHENOMES, AND WITH THE SEVERITY OF LUNG DISEASES. THERE IS AN URGENT NEED TO IDENTIFY AND VALIDATE THE SPECIFICITY AND REGULATORY MECHANISMS OF INFLAMMATORY CELL EPIGENETICS IN DEPTH. THE EPIGENETIC HETEROGENEITY AMONG DIFFERENT SUBSETS OF T CELLS AND AMONG PROMOTERS OR NON-PROMOTERS OF TARGET GENES SHOULD BE FURTHERMORE CLARIFIED IN ACUTE OR CHRONIC LUNG DISEASES AND CANCERS. THE HYPER/HYPO-METHYLATION AND MODIFICATIONS OF CHROMOSOL AND EXTRACHROMOSOMAL DNA MAY RESULT IN ALTERNATIONS IN PROTEINS WITHIN INFLAMMATORY CELLS, WHICH CAN BE IDENTIFIED AS DISEASE-SPECIFIC BIOMARKERS AND THERAPEUTIC TARGETS. 2020 14 3743 48 INSIGHTS FROM GENOMIC STUDIES ON THE ROLE OF SEX STEROIDS IN THE AETIOLOGY OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC NEURO-INFLAMMATORY DISORDER THE DEFINING FEATURE OF WHICH IS THE GROWTH OF TISSUE (LESIONS) THAT RESEMBLES THE ENDOMETRIUM OUTSIDE THE UTERUS. ESTIMATES OF PREVALENCE QUOTE RATES OF ~10% OF WOMEN OF REPRODUCTIVE AGE, EQUATING TO AT LEAST 190 MILLION WOMEN WORLD-WIDE. GENETIC, HORMONAL AND IMMUNOLOGICAL FACTORS HAVE ALL BEEN PROPOSED AS CONTRIBUTING TO RISK FACTORS ASSOCIATED WITH THE DEVELOPMENT OF LESIONS. TWIN STUDIES REPORT THE HERITABLE COMPONENT OF ENDOMETRIOSIS AS ~50%. GENOME-WIDE ASSOCIATION STUDIES (GWAS) HAVE IDENTIFIED SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) THAT APPEAR OVER-REPRESENTED IN PATIENTS WITH ENDOMETRIOSIS, PARTICULARLY THOSE WITH MORE EXTENSIVE DISEASE (STAGE III/IV). IN DIFFERENT SAMPLE POPULATIONS, THERE HAS BEEN REPLICATION OF SNPS NEAR GENES INVOLVED IN OESTROGEN AND OTHER STEROID REGULATED PATHWAYS INCLUDING ESR1 (OESTROGEN RECEPTOR ALPHA), GREB1, HOXA10, WNT4 AND MAPK KINASE SIGNALLING. COMPARISONS WITH GWAS CONDUCTED ON OTHER PATIENT COHORTS HAVE FOUND LINKS WITH REPRODUCTIVE TRAITS (AGE AT MENARCHE) AND DISORDERS (FIBROIDS, ENDOMETRIAL AND OVARIAN CANCER) AND COMMON CO-MORBIDITIES (MIGRAINE, DEPRESSION, ASTHMA). IN SUMMARY, GENETIC ANALYSES HAVE PROVIDED NEW INSIGHTS INTO THE HORMONE-REGULATED PATHWAYS THAT MAY CONTRIBUTE TO INCREASED RISK OF DEVELOPING ENDOMETRIOSIS SOME OF WHICH MAY ACT IN EARLY LIFE. NEW STUDIES ARE NEEDED TO CLARIFY THE RELATIONSHIP BETWEEN THE MANY SNPS IDENTIFIED, THE GENES THAT THEY REGULATE AND THEIR CONTRIBUTION(S) TO DEVELOPMENT OF DIFFERENT FORMS OF ENDOMETRIOSIS. WE HOPE THAT MORE ADVANCED METHODS ALLOWING INTEGRATION BETWEEN GWAS, EPIGENETIC AND TISSUE EXPRESSION DATA WILL IMPROVE RISK ANALYSIS AND REDUCE DIAGNOSITIC DELAY. LAY SUMMARY: ENDOMETRIOSIS IS A DEBILITATING REPRODUCTIVE DISORDER AFFECTING ~10% OF REPRODUCTIVE-AGE WOMEN, AND THOSE ASSIGNED FEMALE AT BIRTH, WHICH CAUSES A RANGE OF SYMPTOMS INCLUDING CHRONIC PAIN AND INFERTILITY. THE REASON WHY SOME, BUT NOT ALL THESE INDIVIDUALS, DEVELOP THE LESIONS THAT CHARACTERISE THE DISEASE ARE POORLY UNDERSTOOD, BUT RECENTLY ATTENTION HAS FOCUSED ON GENETIC RISK FACTORS TO EXPLAIN WHY THE INCIDENCE IS HIGHER IN SOME FAMILIES. STUDIES ON LARGE COHORTS OF PATIENTS WITH COMPARISON OF THEIR DNA TO WOMEN WITHOUT ENDOMETRIOSIS OR WITH OTHER DISORDERS HAVE DOCUMENTED CHANGES IN GENES ASSOCIATED WITH STEROID HORMONE PRODUCTION OR ACTION. THE RESULTS PROVIDE FURTHER EVIDENCE THAT ENDOMETRIOSIS SHARES GENETIC RISK FACTORS WITH OTHER DISORDERS OF THE REPRODUCTIVE SYSTEM AND A PLATFORM FOR NEW IDEAS RELATED TO RISK, BIOMARKERS AND THERAPIES. 2022 15 1562 40 DNA METHYLATION OF ENHANCER ELEMENTS IN MYELOID NEOPLASMS: THINK OUTSIDE THE PROMOTERS? GENE REGULATION THROUGH DNA METHYLATION IS A WELL DESCRIBED PHENOMENON THAT HAS A PROMINENT ROLE IN PHYSIOLOGICAL AND PATHOLOGICAL CELL-STATES. THIS EPIGENETIC MODIFICATION IS USUALLY GROUPED IN REGIONS DENOMINATED CPG ISLANDS, WHICH FREQUENTLY CO-LOCALIZE WITH GENE PROMOTERS, SILENCING THE TRANSCRIPTION OF THOSE GENES. RECENT GENOME-WIDE DNA METHYLATION STUDIES HAVE CHALLENGED THIS PARADIGM, DEMONSTRATING THAT DNA METHYLATION OF REGULATORY REGIONS OUTSIDE PROMOTERS IS ABLE TO INFLUENCE CELL-TYPE SPECIFIC GENE EXPRESSION PROGRAMS UNDER PHYSIOLOGIC OR PATHOLOGIC CONDITIONS. COUPLING GENOME-WIDE DNA METHYLATION ASSAYS WITH HISTONE MARK ANNOTATION HAS ALLOWED FOR THE IDENTIFICATION OF SPECIFIC EPIGENOMIC CHANGES THAT AFFECT ENHANCER REGULATORY REGIONS, REVEALING AN ADDITIONAL LAYER OF COMPLEXITY TO THE EPIGENETIC REGULATION OF GENE EXPRESSION. IN THIS REVIEW, WE SUMMARIZE THE NOVEL EVIDENCE FOR THE MOLECULAR AND BIOLOGICAL REGULATION OF DNA METHYLATION IN ENHANCER REGIONS AND THE DYNAMISM OF THESE CHANGES CONTRIBUTING TO THE FINE-TUNING OF GENE EXPRESSION. WE ALSO ANALYZE THE CONTRIBUTION OF ENHANCER DNA METHYLATION ON THE EXPRESSION OF RELEVANT GENES IN ACUTE MYELOID LEUKEMIA AND CHRONIC MYELOPROLIFERATIVE NEOPLASMS. THE CHARACTERIZATION OF THE ABERRANT ENHANCER DNA METHYLATION PROVIDES NOT ONLY A NOVEL PATHOGENIC MECHANISM FOR DIFFERENT TUMORS BUT ALSO HIGHLIGHTS NOVEL POTENTIAL THERAPEUTIC TARGETS FOR MYELOID DERIVED NEOPLASMS. 2019 16 6616 36 UNCOVERING THE DNA METHYLOME IN CHRONIC LYMPHOCYTIC LEUKEMIA. OVER THE PAST TWO DECADES, ABERRANT DNA METHYLATION HAS EMERGED AS A KEY PLAYER IN THE PATHOGENESIS OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), AND KNOWLEDGE REGARDING ITS BIOLOGICAL AND CLINICAL CONSEQUENCES IN THIS DISEASE HAS EVOLVED RAPIDLY. SINCE THE INITIAL STUDIES RELATING DNA HYPOMETHYLATION TO GENOMIC INSTABILITY IN CLL, A PLETHORA OF REPORTS HAVE FOLLOWED SHOWING THE IMPACT OF DNA HYPERMETHYLATION IN SILENCING VITAL SINGLE GENE PROMOTERS AND THE REVERSIBLE NATURE OF DNA METHYLATION THROUGH INHIBITOR DRUGS. WITH THE RECOGNITION THAT DNA HYPERMETHYLATION EVENTS COULD POTENTIALLY ACT AS NOVEL PROGNOSTIC AND TREATMENT TARGETS IN CLL, THE SEARCH FOR ABERRANTLY METHYLATED GENES, GENE FAMILIES AND PATHWAYS HAS ENSUED. SUBSEQUENTLY, THE ADVENT OF MICROARRAY AND NEXT-GENERATION SEQUENCING TECHNOLOGIES HAS SUPPORTED THE HUNT FOR SUCH TARGETS, ALLOWING EXPLORATION OF THE METHYLATION LANDSCAPE IN CLL AT AN UNPRECEDENTED SCALE. IN LIGHT OF THESE ANALYSES, WE NOW UNDERSTAND THAT DIFFERENT CLL PROGNOSTIC SUBGROUPS ARE CHARACTERIZED BY DIFFERENTIAL METHYLATION PROFILES; WE RECOGNIZE DNA METHYLATION OF A NUMBER OF SIGNALING PATHWAYS GENES TO BE ALTERED IN CLL, AND ACKNOWLEDGE THE ROLE OF DNA METHYLATION OUTSIDE OF TRADITIONAL CPG ISLAND PROMOTERS AS FUNDAMENTAL PLAYERS IN THE REGULATION OF GENE EXPRESSION. TODAY, THE SIGNIFICANCE AND TIMING OF ALTERED DNA METHYLATION WITHIN THE COMPLEX EPIGENETIC NETWORK OF CONCOMITANT EPIGENETIC MESSENGERS SUCH AS HISTONES AND MIRNAS IS AN INTENSIVE AREA OF RESEARCH. IN CLL, IT APPEARS THAT DNA METHYLATION IS A RATHER STABLE EPIGENETIC MARK OCCURRING RATHER EARLY IN THE DISEASE PATHOGENESIS. HOWEVER, OTHER CONSEQUENCES, SUCH AS HOW AND WHY ABERRANT METHYLATION MARKS OCCUR, ARE LESS EXPLORED. IN THIS REVIEW, WE WILL NOT ONLY PROVIDE A COMPREHENSIVE SUMMARY OF THE CURRENT LITERATURE WITHIN THE EPIGENETICS FIELD OF CLL, BUT ALSO HIGHLIGHT SOME OF THE NOVEL FINDINGS RELATING TO WHEN, WHERE, WHY AND HOW ALTERED DNA METHYLATION MATERIALIZES IN CLL. 2013 17 3964 43 LONG NONCODING RNAS IN LUNG CANCER. DESPITE GREAT PROGRESS IN RESEARCH AND TREATMENT OPTIONS, LUNG CANCER REMAINS THE LEADING CAUSE OF CANCER-RELATED DEATHS WORLDWIDE. ONCOGENIC DRIVER MUTATIONS IN PROTEIN-ENCODING GENES WERE DEFINED AND ALLOW FOR PERSONALIZED THERAPIES BASED ON GENETIC DIAGNOSES. NONETHELESS, DIAGNOSIS OF LUNG CANCER MOSTLY OCCURS AT LATE STAGES, AND CHRONIC TREATMENT IS FOLLOWED BY A FAST ONSET OF CHEMORESISTANCE. HENCE, THERE IS AN URGENT NEED FOR RELIABLE BIOMARKERS AND ALTERNATIVE TREATMENT OPTIONS. WITH THE ERA OF WHOLE GENOME AND TRANSCRIPTOME SEQUENCING TECHNOLOGIES, LONG NONCODING RNAS EMERGED AS A NOVEL CLASS OF VERSATILE, FUNCTIONAL RNA MOLECULES. ALTHOUGH FOR MOST OF THEM THE MECHANISM OF ACTION REMAINS TO BE DEFINED, ACCUMULATING EVIDENCE CONFIRMS THEIR INVOLVEMENT IN VARIOUS ASPECTS OF LUNG TUMORIGENESIS. THEY ARE FUNCTIONAL ON THE EPIGENETIC, TRANSCRIPTIONAL, AND POSTTRANSCRIPTIONAL LEVEL AND ARE REGULATORS OF PATHOPHYSIOLOGICAL KEY PATHWAYS INCLUDING CELL GROWTH, APOPTOSIS, AND METASTASIS. LONG NONCODING RNAS ARE GAINING INCREASING ATTENTION AS POTENTIAL BIOMARKERS AND A NOVEL CLASS OF DRUGGABLE MOLECULES. IT HAS BECOME CLEAR THAT WE ARE ONLY BEGINNING TO UNDERSTAND THE COMPLEXITY OF TUMORIGENIC PROCESSES. THE CLINICAL INTEGRATION OF LONG NONCODING RNAS IN TERMS OF PROGNOSTIC AND PREDICTIVE BIOMARKER SIGNATURES AND ADDITIONAL CANCER TARGETS COULD PROVIDE A CHANCE TO INCREASE THE THERAPEUTIC BENEFIT. HERE, WE REVIEW THE CURRENT KNOWLEDGE ABOUT THE EXPRESSION, REGULATION, BIOLOGICAL FUNCTION, AND CLINICAL RELEVANCE OF LONG NONCODING RNAS IN LUNG CANCER. 2016 18 606 38 BEYOND GENETICS--THE EMERGING ROLE OF EPIGENETIC CHANGES IN HEMATOPOIETIC MALIGNANCIES. THE TERM EPIGENETIC REFERS TO A HERITABLE CHANGE IN GENE EXPRESSION THAT IS MEDIATED BY MECHANISMS OTHER THAN ALTERATIONS IN THE PRIMARY NUCLEOTIDE SEQUENCE. DNA METHYLATION AT CYTOSINE BASES THAT ARE LOCATED 5' TO GUANOSINE WITHIN A CPG DINUCLEOTIDE IS THE MAIN EPIGENETIC MODIFICATION IN HUMANS. PATTERNS OF DNA METHYLATION ARE PROFOUNDLY DERANGED IN HUMAN CANCER AND COMPRISE GENOME-WIDE LOSSES AS WELL AS REGIONAL GAINS IN DNA METHYLATION. HYPERMETHYLATION OF CPG ISLANDS WITHIN GENE PROMOTER REGIONS IS ASSOCIATED WITH TRANSCRIPTIONAL INACTIVATION AND REPRESENTS, IN ADDITION TO GENETIC ABERRATIONS, AN IMPORTANT MECHANISM OF GENE SILENCING IN THE PATHOGENESIS OF HEMATOPOIETIC MALIGNANCIES. THIS EPIGENETIC PHENOMENON ACTS AS AN ALTERNATIVE TO MUTATIONS AND DELETIONS TO DISRUPT TUMOR SUPPRESSOR GENE FUNCTION. A LARGE NUMBER OF GENES INVOLVING FUNDAMENTAL CELLULAR PATHWAYS MAY BE AFFECTED IN VIRTUALLY ALL TYPES OF HUMAN CANCER BY ABERRANT CPG ISLAND METHYLATION IN ASSOCIATION WITH TRANSCRIPTIONAL SILENCING. ALTERED METHYLATION PATTERNS CAN BE USED AS BIOMARKERS FOR CANCER DETECTION, ASSESSMENT OF PROGNOSIS, AND PREDICTION OF RESPONSE TO ANTITUMOR TREATMENT. FURTHERMORE, CLINICAL TRIALS USING EPIGENETICALLY TARGETED THERAPIES HAVE YIELDED PROMISING RESULTS FOR ACUTE AND CHRONIC LEUKEMIAS AS WELL AS FOR MYELODYSPLASTIC SYNDROMES. THE EXPLORATION OF OUR GROWING KNOWLEDGE ABOUT EPIGENETIC ABERRATIONS MAY HELP DEVELOP NOVEL STRATEGIES FOR THE DIAGNOSIS AND TREATMENT OF HEMATOPOIETIC MALIGNANCIES IN THE FUTURE. 2004 19 3089 31 GENOMIC AND EPIGENOMIC ALTERATIONS IN CHRONIC LYMPHOCYTIC LEUKEMIA. CHRONIC LYMPHOCYTIC LEUKEMIA IS A COMMON DISEASE IN WESTERN COUNTRIES AND HAS HETEROGENEOUS CLINICAL BEHAVIOR. THE RELEVANCE OF THE GENETIC BASIS OF THE DISEASE HAS COME TO THE FOREFRONT RECENTLY, WITH GENOME-WIDE STUDIES THAT HAVE PROVIDED A COMPREHENSIVE VIEW OF STRUCTURAL VARIANTS, SOMATIC MUTATIONS, AND DIFFERENT LAYERS OF EPIGENETIC CHANGES. THE MUTATIONAL LANDSCAPE IS CHARACTERIZED BY RELATIVELY COMMON COPY NUMBER ALTERATIONS, A FEW MUTATED GENES OCCURRING IN 10-15% OF CASES, AND A LARGE NUMBER OF GENES MUTATED IN A SMALL NUMBER OF CASES. THE EPIGENOMIC PROFILE HAS REVEALED A MARKED REPROGRAMMING OF REGULATORY REGIONS IN TUMOR CELLS COMPARED WITH NORMAL B CELLS. ALL OF THESE ALTERATIONS ARE DIFFERENTIALLY DISTRIBUTED IN CLINICAL AND BIOLOGICAL SUBSETS OF THE DISEASE, INDICATING THAT THEY MAY UNDERLIE THE HETEROGENEOUS EVOLUTION OF THE DISEASE. THESE GLOBAL STUDIES ARE REVEALING THE MOLECULAR COMPLEXITY OF CHRONIC LYMPHOCYTIC LEUKEMIA AND PROVIDE NEW PERSPECTIVES THAT HAVE HELPED TO UNDERSTAND ITS PATHOGENIC MECHANISMS AND IMPROVE THE CLINICAL MANAGEMENT OF PATIENTS. 2020 20 2033 35 EPIGENETIC CHANGES IN SOLID AND HEMATOPOIETIC TUMORS. THERE ARE THREE CONNECTED MOLECULAR MECHANISMS OF EPIGENETIC CELLULAR MEMORY IN MAMMALIAN CELLS: DNA METHYLATION, HISTONE MODIFICATIONS, AND RNA INTERFERENCE. THE FIRST TWO HAVE NOW BEEN FIRMLY LINKED TO NEOPLASTIC TRANSFORMATION. HYPERMETHYLATION OF CPG-RICH PROMOTERS TRIGGERS LOCAL HISTONE CODE MODIFICATIONS RESULTING IN A CELLULAR CAMOUFLAGE MECHANISM THAT SEQUESTERS GENE PROMOTERS AWAY FROM TRANSCRIPTION FACTORS AND RESULTS IN STABLE SILENCING. THIS NORMALLY RESTRICTED MECHANISM IS UBIQUITOUSLY USED IN CANCER TO SILENCE HUNDREDS OF GENES, AMONG WHICH SOME CRITICALLY CONTRIBUTE TO THE NEOPLASTIC PHENOTYPE. VIRTUALLY EVERY PATHWAY IMPORTANT TO CANCER FORMATION IS AFFECTED BY THIS PROCESS. METHYLATION PROFILING OF HUMAN CANCERS REVEALS TISSUE-SPECIFIC EPIGENETIC SIGNATURES, AS WELL AS TUMOR-SPECIFIC SIGNATURES, REFLECTING IN PARTICULAR THE PRESENCE OF EPIGENETIC INSTABILITY IN A SUBSET OF CANCERS AFFECTED BY THE CPG ISLAND METHYLATOR PHENOTYPE. GENERALLY, METHYLATION PATTERNS CAN BE TRACED TO A TISSUE-SPECIFIC, PROLIFERATION-DEPENDENT ACCUMULATION OF ABERRANT PROMOTER METHYLATION IN AGING TISSUES, A PROCESS THAT CAN BE ACCELERATED BY CHRONIC INFLAMMATION AND LESS WELL-DEFINED MECHANISMS INCLUDING, POSSIBLY, DIET AND GENETIC PREDISPOSITION. THE EPIGENETIC MACHINERY CAN ALSO BE ALTERED IN CANCER BY SPECIFIC LESIONS IN EPIGENETIC EFFECTOR GENES, OR BY ABERRANT RECRUITMENT OF THESE GENES BY MUTANT TRANSCRIPTION FACTORS AND COACTIVATORS. EPIGENETIC PATTERNS ARE PROVING CLINICALLY USEFUL IN HUMAN ONCOLOGY VIA RISK ASSESSMENT, EARLY DETECTION, AND PROGNOSTIC CLASSIFICATION. PHARMACOLOGIC MANIPULATION OF THESE PATTERNS-EPIGENETIC THERAPY-IS ALSO POISED TO CHANGE THE WAY WE TREAT CANCER IN THE CLINIC. 2005