1 5016 134 PERSISTENT BACTERIAL COINFECTION OF A COVID-19 PATIENT CAUSED BY A GENETICALLY ADAPTED PSEUDOMONAS AERUGINOSA CHRONIC COLONIZER. PSEUDOMONAS AERUGINOSA IS A BIOFILM-FORMING OPPORTUNISTIC PATHOGEN WHICH CAUSES CHRONIC INFECTIONS IN IMMUNOCOMPROMISED PATIENTS AND LEADS TO HIGH MORTALITY RATE. IT IS IDENTIFIED AS A COMMON COINFECTING PATHOGEN IN COVID-19 PATIENTS CAUSING EXACERBATION OF ILLNESS. IN OUR HOSPITAL, P. AERUGINOSA IS ONE OF THE TOP COINFECTING BACTERIA IDENTIFIED AMONG COVID-19 PATIENTS. WE COLLECTED A STRONG BIOFILM-FORMING P. AERUGINOSA STRAIN DISPLAYING SMALL COLONY VARIANT MORPHOLOGY FROM A SEVERE COVID-19 PATIENT. GENOMIC AND TRANSCRIPTOMIC SEQUENCING ANALYSES WERE PERFORMED WITH PHENOTYPIC VALIDATION TO INVESTIGATE ITS ADAPTATION IN SARS-COV-2 INFECTED ENVIRONMENT. GENOMIC CHARACTERIZATION PREDICTED SPECIFIC GENOMIC ISLANDS HIGHLY ASSOCIATED WITH VIRULENCE, TRANSCRIPTIONAL REGULATION, AND DNA RESTRICTION-MODIFICATION SYSTEMS. EPIGENETIC ANALYSIS REVEALED A SPECIFIC N(6)-METHYL ADENINE (M(6)A) METHYLATING PATTERN INCLUDING METHYLATION OF ALGINATE, FLAGELLAR AND QUORUM SENSING ASSOCIATED GENES. DIFFERENTIAL GENE EXPRESSION ANALYSIS INDICATED THAT THIS ISOLATE FORMED EXCESSIVE BIOFILM BY REDUCING FLAGELLAR FORMATION (7.4 TO 1,624.1 FOLDS) AND OVERPRODUCING EXTRACELLULAR MATRIX COMPONENTS INCLUDING CDRA (4.4 FOLDS), ALGINATE (5.2 TO 29.1 FOLDS) AND PEL (4.8-5.5 FOLDS). IN SUMMARY, WE DEMONSTRATED THAT P. AEUGINOSA CLINICAL ISOLATES WITH NOVEL EPIGENETIC MARKERS COULD FORM EXCESSIVE BIOFILM, WHICH MIGHT ENHANCE ITS ANTIBIOTIC RESISTANCE AND IN VIVO COLONIZATION IN COVID-19 PATIENTS. 2021 2 5340 39 QUORUM SENSING AND VIRULENCE OF PSEUDOMONAS AERUGINOSA DURING LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. PSEUDOMONAS AERUGINOSA IS THE PREDOMINANT MICROORGANISM IN CHRONIC LUNG INFECTION OF CYSTIC FIBROSIS PATIENTS. THE CHRONIC LUNG INFECTION IS PRECEDED BY INTERMITTENT COLONIZATION. WHEN THE CHRONIC INFECTION BECOMES ESTABLISHED, IT IS WELL ACCEPTED THAT THE ISOLATED STRAINS DIFFER PHENOTYPICALLY FROM THE INTERMITTENT STRAINS. DOMINATING CHANGES ARE THE SWITCH TO MUCOIDITY (ALGINATE OVERPRODUCTION) AND LOSS OF EPIGENETIC REGULATION OF VIRULENCE SUCH AS THE QUORUM SENSING (QS). TO ELUCIDATE THE DYNAMICS OF P. AERUGINOSA QS SYSTEMS DURING LONG TERM INFECTION OF THE CF LUNG, WE HAVE INVESTIGATED 238 ISOLATES OBTAINED FROM 152 CF PATIENTS AT DIFFERENT STAGES OF INFECTION RANGING FROM INTERMITTENT TO LATE CHRONIC. ISOLATES WERE CHARACTERIZED WITH REGARD TO QS SIGNAL MOLECULES, ALGINATE, RHAMNOLIPID AND ELASTASE PRODUCTION AND MUTANT FREQUENCY. THE GENETIC BASIS FOR CHANGE IN QS REGULATION WERE INVESTIGATED AND IDENTIFIED BY SEQUENCE ANALYSIS OF LASR, RHLR, LASI AND RHLI. THE FIRST QS SYSTEM TO BE LOST WAS THE ONE ENCODED BY LAS SYSTEM 12 YEARS (MEDIAN VALUE) AFTER THE ONSET OF THE LUNG INFECTION WITH SUBSEQUENT LOSS OF THE RHL ENCODED SYSTEM AFTER 17 YEARS (MEDIAN VALUE) SHOWN AS DEFICIENCIES IN PRODUCTION OF THE 3-OXO-C12-HSL AND C4-HSL QS SIGNAL MOLECULES RESPECTIVELY. THE CONCOMITANT DEVELOPMENT OF QS MALFUNCTION SIGNIFICANTLY CORRELATED WITH THE REDUCED PRODUCTION OF RHAMNOLIPIDS AND ELASTASE AND WITH THE OCCURRENCE OF MUTATIONS IN THE REGULATORY GENES LASR AND RHLR. ACCUMULATION OF MUTATIONS IN BOTH LASR AND RHLR CORRELATED WITH DEVELOPMENT OF HYPERMUTABILITY. INTERESTINGLY, A HIGHER NUMBER OF MUCOID ISOLATES WERE FOUND TO PRODUCE C4-HSL SIGNAL MOLECULES AND RHAMNOLIPIDS COMPARED TO THE NON-MUCOID ISOLATES. AS SEEN FROM THE PRESENT DATA, WE CAN CONCLUDE THAT P. AERUGINOSA AND PARTICULARLY THE MUCOID STRAINS DO NOT LOSE THE QS REGULATION OR THE ABILITY TO PRODUCE RHAMNOLIPIDS UNTIL THE LATE STAGE OF THE CHRONIC INFECTION. 2010 3 6368 40 THE ROLE OF MICRORNAS IN CHRONIC PSEUDOMONAS LUNG INFECTION IN CYSTIC FIBROSIS. BACKGROUND: CYSTIC FIBROSIS (CF) IS THE MOST COMMON LIFE LIMITING GENETIC DISORDER, CHARACTERIZED BY CHRONIC RESPIRATORY FAILURE SECONDARY TO INFLAMMATION AND CHRONIC BACTERIAL LUNG INFECTION. PSEUDOMONAS AERUGINOSA LUNG INFECTION IS ASSOCIATED WITH MORE SEVERE LUNG DISEASE AND RAPID PROGRESSION OF RESPIRATORY FAILURE WHEN COMPARED TO STAPHYLOCOCCUS AUREUS INFECTION. WE HYPOTHESIZED THAT A SPECIFIC SIGNATURE OF EPIGENETIC FACTORS TARGETING SPECIFIC GENE TRANSCRIPTS CONTRIBUTES TO THE INCREASED MORBIDITY SEEN IN CF PATIENTS WITH CHRONIC PSEUDOMONAS INFECTION. METHODS: WE COLLECTED EXHALED BREATH CONDENSATE (EBC) FROM 27 SUBJECTS AND EVALUATED MIRNA SIGNATURES IN THESE SAMPLES USING COMMERCIAL PCR ARRAY. WE IDENTIFIED PREDICTED MRNA TARGETS AND ASSOCIATED SIGNALING PATHWAYS USING INGENUITY PATHWAY ANALYSIS. RESULTS: WE FOUND 11 DIFFERENTIALLY EXPRESSED MIRNAS IN EBC OF PATIENTS INFECTED WITH PSEUDOMONAS AERUGINOSA COMPARED TO EBC FROM CF PATIENTS WHO WERE NOT CHRONICALLY INFECTED WITH PSEUDOMONAS AERUGINOSA (P < 0.05). SIX OF THESE MIRNAS (HSA-MIRNA-1247, HSA-MIRNA-1276, HSA-MIRNA-449C, HSA-MIRNA-3170, HSA-MIRNA-432-5P AND HSA-MIR-548) WERE SIGNIFICANTLY DIFFERENT IN THE CF PSEUDOMONAS POSITIVE GROUP WHEN COMPARED TO BOTH THE CF PSEUDOMONAS NEGATIVE GROUP AND HEALTHY CONTROL GROUP. INGENUITY PATHWAY ANALYSIS (IPA) REVEALED ORGANISMAL INJURY AND ABNORMALITIES, REPRODUCTIVE SYSTEM DISEASE AND CANCER AS THE TOP DISEASES AND BIO FUNCTIONS ASSOCIATED WITH THESE MIRNAS. IPA ALSO DETECTED RELA, JUN, TNF, IL-10, CTNNB1, IL-13, SERPINB8, CALM1, STARD3NL, SFI1, CD55, RPS6KA4, TTC36 AND HIST1H3D AS THE TOP TARGET GENES FOR THESE MIRNAS. CONCLUSION: OUR STUDY IDENTIFIED 6 MIRNAS AS EPIGENETIC FACTORS SPECIFICALLY ASSOCIATED WITH CHRONIC PSEUDOMONAS INFECTION IN PATIENTS WITH CF. 2019 4 1619 59 DNA METHYLTRANSFERASE REGULATES NITRIC OXIDE HOMEOSTASIS AND VIRULENCE IN A CHRONICALLY ADAPTED PSEUDOMONAS AERUGINOSA STRAIN. OPPORTUNISTIC PATHOGENS SUCH AS PSEUDOMONAS AERUGINOSA ADAPT THEIR GENOMES RAPIDLY DURING CHRONIC INFECTIONS. UNDERSTANDING THEIR EPIGENETIC REGULATION MAY PROVIDE BIOMARKERS FOR DIAGNOSIS AND REVEAL NOVEL REGULATORY MECHANISMS. WE PERFORMED SINGLE-MOLECULE REAL-TIME SEQUENCING (SMRT-SEQ) TO CHARACTERIZE THE METHYLOME OF A CHRONICALLY ADAPTED P. AERUGINOSA CLINICAL STRAIN, TBCF10839. TWO N(6)-METHYLADENINE (6MA) METHYLATION RECOGNITION MOTIFS (RCCANNNNNNNTGAR AND TRGANNNNNNTGC [MODIFICATION SITES ARE IN BOLD]) WERE IDENTIFIED AND PREDICTED AS NEW TYPE I METHYLATION SITES USING REBASE ANALYSIS. WE CONFIRMED THAT THE MOTIF TRGANNNNNNTGC WAS METHYLATED BY THE METHYLTRANSFERASE (MTASE) M.PAETBCFII, ACCORDING TO METHYLATION SENSITIVITY ASSAYS IN VIVO AND VITRO. TRANSCRIPTOMIC ANALYSIS SHOWED THAT A DELTAPAETBCFIIM KNOCKOUT MUTANT SIGNIFICANTLY DOWNREGULATED NITRIC OXIDE REDUCTASE (NOR) REGULATION AND EXPRESSION OF CODING GENES SUCH AS NOSR AND NORB, WHICH CONTAIN METHYLATED MOTIFS IN THEIR PROMOTERS OR CODING REGIONS. THE DELTAPAETBCFIIM STRAIN EXHIBITED REDUCED INTERCELLULAR SURVIVAL CAPACITY IN NO-PRODUCING RAW264.7 MACROPHAGES AND ATTENUATED VIRULENCE IN A GALLERIA MELLONELLA INFECTION MODEL; THE COMPLEMENTED STRAIN RECOVERED THESE DEFECTIVE PHENOTYPES. FURTHER PHYLOGENETIC ANALYSIS DEMONSTRATED THAT HOMOLOGS OF M.PAETBCFII OCCUR FREQUENTLY IN P. AERUGINOSA AS WELL AS OTHER BACTERIAL SPECIES. OUR WORK THEREFORE PROVIDED NEW INSIGHTS INTO THE RELATIONSHIP BETWEEN DNA METHYLATION, NO DETOXIFICATION, AND BACTERIAL VIRULENCE, LAYING A FOUNDATION FOR FURTHER EXPLORING THE MOLECULAR MECHANISM OF DNA METHYLTRANSFERASE IN REGULATING THE PATHOGENICITY OF P. AERUGINOSA. IMPORTANCE PSEUDOMONAS AERUGINOSA IS AN OPPORTUNISTIC PATHOGEN WHICH CAUSES ACUTE AND CHRONIC INFECTIONS THAT ARE DIFFICULT TO TREAT. COMPARATIVE GENOMIC ANALYSIS HAS SHOWED BROAD GENOME DIVERSITY AMONG P. AERUGINOSA CLINICAL STRAINS AND REVEALED THEIR DIFFERENT REGULATORY TRAITS COMPARED TO THE LABORATORY STRAINS. WHILE CURRENT INVESTIGATION OF THE EPIGENETICS OF P. AERUGINOSA IS STILL LACKING, UNDERSTANDING EPIGENETIC REGULATION MAY PROVIDE BIOMARKERS FOR DIAGNOSIS AND FACILITATE DEVELOPMENT OF NOVEL THERAPIES. DENITRIFICATION CAPABILITY IS CRITICAL FOR MICROBIAL VERSATILITY IN RESPONSE TO DIFFERENT ENVIRONMENTAL STRESS CONDITIONS, INCLUDING THE BACTERIAL INFECTION PROCESS, WHERE NITRIC OXIDE (NO) CAN BE GENERATED BY PHAGOCYTIC CELLS. THE DENITRIFICATION REGULATION MECHANISMS HAVE BEEN STUDIED INTENSIVELY AT GENETIC AND BIOCHEMICAL LEVELS. HOWEVER, THERE IS VERY LITTLE EVIDENCE ABOUT THE EPIGENETIC REGULATION OF BACTERIAL DENITRIFICATION MECHANISM. P. AERUGINOSA TBCF10839 IS A CHRONICALLY HOST-ADAPTED STRAIN ISOLATED FROM A CYSTIC FIBROSIS (CF) PATIENT WITH SPECIAL ANTIPHAGOCYTOSIS CHARACTERISTICS. HERE, WE INVESTIGATED THE REGULATORY EFFECT OF AN ORPHAN DNA MTASE, M.PAETBCFII, IN P. AERUGINOSA TBCF10839. WE DEMONSTRATED THAT THE DNA MTASE REGULATES THE TRANSCRIPTION OF DENITRIFICATION GENES REPRESENTED BY NOR AND AFFECTS ANTIPHAGOCYTIC ABILITY IN BACTERIA. IN SILICO ANALYSIS SUGGESTED THAT DNA METHYLATION MODIFICATION MAY ENHANCE GENE EXPRESSION BY AFFECTING THE BINDING OF TRANSACTING FACTORS SUCH AS DNR AND RPON. OUR FINDINGS NOT ONLY DEEPEN THE UNDERSTANDING OF THE ROLE OF DNA MTASE IN TRANSCRIPTIONAL REGULATION IN P. AERUGINOSA BUT ALSO PROVIDE A THEORETICAL FOUNDATION FOR THE IN-DEPTH STUDY OF THE MOLECULAR MECHANISM OF THE EPIGENETIC REGULATION ON DENITRIFICATION, VIRULENCE, AND HOST-PATHOGEN INTERACTION. 2022 5 1118 38 COMPARATIVE GENOTYPING AND PHENOTYPING OF ASPERGILLUS FUMIGATUS ISOLATES FROM HUMANS, DOGS AND THE ENVIRONMENT. BACKGROUND: ASPERGILLUS FUMIGATUS IS A UBIQUITOUS SAPROTROPHIC FUNGUS AND AN OPPORTUNISTIC PATHOGEN OF HUMANS AND ANIMALS. HUMANS AND ANIMALS CAN INHALE HUNDREDS OF A. FUMIGATUS SPORES DAILY. NORMALLY THIS IS HARMLESS FOR HUMANS, BUT IN CASE OF IMMUNODEFICIENCY, INVASIVE PULMONARY ASPERGILLOSIS (IPA) CAN DEVELOP WITH A HIGH MORTALITY RATE. A. FUMIGATUS ALSO CAUSES NON-INVASIVE MYCOSES LIKE SINO-NASAL ASPERGILLOSIS (SNA) IN DOGS. RESULTS: IN THIS STUDY WE COMPARED A. FUMIGATUS ISOLATES FROM HUMANS WITH SUSPECTED IPA, DOGS WITH SNA, AND A SET OF ENVIRONMENTAL ISOLATES. PHYLOGENETIC INFERENCE BASED ON CALMODULIN (CAM) AND BETA-TUBULIN (BENA) SEQUENCES DID NOT REVEAL A. FUMIGATUS SUB-GROUPS LINKED TO THE ORIGIN OF THE ISOLATES. GENOTYPING AND MICROSATELLITE ANALYSIS SHOWED THAT EACH DOG WAS INFECTED BY ONE A. FUMIGATUS GENOTYPE, WHEREAS HUMAN PATIENTS HAD MIXED INFECTIONS. AZOLE RESISTANCE WAS DETERMINED BY ANTIFUNGAL SUSCEPTIBILITY TESTING AND SEQUENCING OF THE CYP51A GENE. A TOTAL OF 12 OUT OF 29 HUMAN ISOLATES AND 1 OUT OF 27 ENVIRONMENTAL ISOLATES WERE AZOLE RESISTANT. OF THE AZOLE RESISTANT STRAINS, 11 HUMAN ISOLATES SHOWED TR(34)/L98H (N = 6) OR TR46/Y121F/T289A (N = 5). PHENOTYPICALLY, ISOLATES FROM DOGS WERE MORE VARIABLE IN GROWTH SPEED AND MORPHOLOGY WHEN COMPARED TO THOSE ISOLATED FROM HUMAN AND THE ENVIRONMENT. CONCLUSIONS: 1. A. FUMIGATUS FROM DOGS WITH SNA ARE PHENOTYPICALLY VERY DIVERSE IN CONTRAST TO THEIR ENVIRONMENTAL AND HUMAN COUNTERPARTS. 2. PHENOTYPIC VARIABILITY CAN BE INDUCED DURING THE CHRONIC INFECTION PROCESS IN THE SINUS OF THE DOGS. THE BASIS OF THIS HETEROGENEITY MIGHT BE DUE TO GENOMIC DIFFERENCES AND/OR EPIGENETIC VARIATIONS. 3. DIFFERENCES IN DOGS IS A COULD BE A RESULT OF WITHIN-HOST ADAPTION AND MIGHT BE TRIGGERED BY ENVIRONMENTAL FACTORS IN THE SINUS, HOWEVER THIS HYPOTHESIS STILL NEEDS TO BE TESTED. 2018 6 1948 42 EPIGENETIC ACQUISITION OF INDUCIBILITY OF TYPE III CYTOTOXICITY IN P. AERUGINOSA. BACKGROUND: PSEUDOMONAS AERUGINOSA, AN OPPORTUNISTIC PATHOGEN, IS OFTEN ENCOUNTERED IN CHRONIC LUNG DISEASES SUCH AS CYSTIC FIBROSIS OR CHRONIC OBSTRUCTIVE PNEUMONIA, AS WELL AS ACUTE SETTINGS LIKE MECHANICAL VENTILATION ACQUIRED PNEUMONIA OR NEUTROPENIC PATIENTS. IT IS A MAJOR CAUSE OF MORTALITY AND MORBIDITY IN THESE DISEASES. IN LUNGS, P. AERUGINOSA SETTLES IN A BIOFILM MODE OF GROWTH WITH THE SECRETION OF EXOPOLYSACCHARIDES IN WHICH IT IS ENCAPSULATED, ENHANCING ITS ANTIBIOTIC RESISTANCE AND CONTRIBUTING TO THE RESPIRATORY DEFICIENCY OF PATIENTS. HOWEVER, BACTERIA MUST FIRST MULTIPLY TO A HIGH DENSITY AND DISPLAY A CYTOTOXIC PHENOTYPE TO AVOID THE HOST'S DEFENCES. A VIRULENCE DETERMINANT IMPLICATED IN THIS STEP OF INFECTION IS THE TYPE III SECRETION SYSTEM (TTSS), ALLOWING TOXIN INJECTION DIRECTLY INTO HOST CELLS. AT THE BEGINNING OF THE INFECTION, MOST STRAINS ISOLATED FROM PATIENTS' LUNGS POSSESS AN INDUCIBLE TTSS ALLOWING TOXINS INJECTION OR SECRETION UPON IN VIVO OR IN VITRO ACTIVATION SIGNALS. AS THE INFECTION PERSISTS MOST OF THE BACTERIA PERMANENTLY LOOSE THIS CAPACITY, ALTHOUGH NO MUTATIONS HAVE BEEN EVIDENCED. WE NAME "NON INDUCIBLE" THIS PHENOTYPE. AS SUGGESTED BY THE PRESENCE OF A POSITIVE FEEDBACK CIRCUIT IN THE REGULATORY NETWORK CONTROLLING TTSS EXPRESSION, IT MAY BE DUE TO AN EPIGENETIC SWITCH ALLOWING HERITABLE PHENOTYPIC MODIFICATIONS WITHOUT GENOTYPE'S MUTATIONS. RESULTS: USING THE GENERALISED LOGICAL METHOD, WE DESIGNED A MINIMAL MODEL OF THE TTSS REGULATORY NETWORK THAT COULD SUPPORT THE EPIGENETIC HYPOTHESIS, AND STUDIED ITS DYNAMICS WHICH HELPED TO DEFINE A DISCRIMINATING EXPERIMENTAL SCENARIO SUFFICIENT TO VALIDATE THE EPIGENETIC HYPOTHESIS. A MATHEMATICAL FRAMEWORK BASED ON FORMAL METHODS FROM COMPUTER SCIENCE ALLOWED A RIGOROUS VALIDATION AND CERTIFICATION OF PARAMETERS OF THIS MODEL LEADING TO EPIGENETIC BEHAVIOUR. THEN, WE DEMONSTRATED THAT A NON INDUCIBLE STRAIN OF P. AERUGINOSA CAN STABLY ACQUIRE THE CAPACITY TO BE INDUCED BY CALCIUM DEPLETION FOR THE TTSS AFTER A SHORT PULSE OF A REGULATORY PROTEIN. FINALLY, THE INCREASED CYTOTOXICITY OF A STRAIN AFTER THIS EPIGENETIC SWITCH WAS DEMONSTRATED IN VIVO IN AN ACUTE PULMONARY INFECTION MODEL. CONCLUSION: THESE RESULTS MAY OFFER NEW PERSPECTIVES FOR THERAPEUTIC STRATEGIES TO PREVENT LETHAL INFECTIONS BY P. AERUGINOSA BY REVERTING THE EPIGENETIC INDUCIBILITY OF TYPE III CYTOTOXICITY. 2006 7 569 26 BCOR AND BCORL1 MUTATIONS IN MYELODYSPLASTIC SYNDROMES AND RELATED DISORDERS. PATIENTS WITH LOW-RISK MYELODYSPLASTIC SYNDROMES (MDS) THAT RAPIDLY PROGRESS TO ACUTE MYELOID LEUKEMIA (AML) REMAIN A CHALLENGE IN DISEASE MANAGEMENT. USING WHOLE-EXOME SEQUENCING OF AN MDS PATIENT, WE IDENTIFIED A SOMATIC MUTATION IN THE BCOR GENE ALSO MUTATED IN AML. SEQUENCING OF BCOR AND RELATED BCORL1 GENES IN A COHORT OF 354 MDS PATIENTS IDENTIFIED 4.2% AND 0.8% OF MUTATIONS RESPECTIVELY. BCOR MUTATIONS WERE ASSOCIATED WITH RUNX1 (P = .002) AND DNMT3A MUTATIONS (P = .015). BCOR IS ALSO MUTATED IN CHRONIC MYELOMONOCYTIC LEUKEMIA PATIENTS (7.4%) AND BCORL1 IN AML PATIENTS WITH MYELODYSPLASIA-RELATED CHANGES (9.1%). USING DEEP SEQUENCING, WE SHOW THAT BCOR MUTATIONS ARISE AFTER MUTATIONS AFFECTING GENES INVOLVED IN SPLICING MACHINERY OR EPIGENETIC REGULATION. IN UNIVARIATE ANALYSIS, BCOR MUTATIONS WERE ASSOCIATED WITH POOR PROGNOSIS IN MDS (OVERALL SURVIVAL [OS]: P = .013; CUMULATIVE INCIDENCE OF AML TRANSFORMATION: P = .005). MULTIVARIATE ANALYSIS INCLUDING AGE, INTERNATIONAL PROGNOSTIC SCORING SYSTEM, TRANSFUSION DEPENDENCY, AND MUTATIONAL STATUS CONFIRMED A SIGNIFICANT INFERIOR OS TO PATIENTS WITH A BCOR MUTATION (HAZARD RATIO, 3.3; 95% CONFIDENCE INTERVAL, 1.4-8.1; P = .008). THESE DATA SUGGEST THAT BCOR MUTATIONS DEFINE THE CLINICAL COURSE RATHER THAN DISEASE INITIATION. DESPITE INFREQUENT MUTATIONS, BCOR ANALYSES SHOULD BE CONSIDERED IN RISK STRATIFICATION. 2013 8 2273 40 EPIGENETIC REGULATION ALTERS BIOFILM ARCHITECTURE AND COMPOSITION IN MULTIPLE CLINICAL ISOLATES OF NONTYPEABLE HAEMOPHILUS INFLUENZAE. BIOFILMS PLAY A CRITICAL ROLE IN THE COLONIZATION, PERSISTENCE, AND PATHOGENESIS OF MANY HUMAN PATHOGENS. MULTIPLE MUCOSA-ASSOCIATED PATHOGENS HAVE EVOLVED A MECHANISM OF RAPID ADAPTATION, TERMED THE PHASEVARION, WHICH FACILITATES A COORDINATED REGULATION OF NUMEROUS GENES THROUGHOUT THE BACTERIAL GENOME. THIS EPIGENETIC REGULATION OCCURS VIA PHASE VARIATION OF A DNA METHYLTRANSFERASE, MOD. THE PHASEVARION OF NONTYPEABLE HAEMOPHILUS INFLUENZAE (NTHI) SIGNIFICANTLY AFFECTS THE SEVERITY OF EXPERIMENTAL OTITIS MEDIA AND REGULATES SEVERAL DISEASE-RELATED PROCESSES. HOWEVER, THE ROLE OF THE NTHI PHASEVARION IN BIOFILM FORMATION IS UNCLEAR. THE PRESENT STUDY SHOWS THAT THE PHASEVARIONS OF MULTIPLE NTHI CLINICAL ISOLATES REGULATE IN VITRO BIOFILM FORMATION UNDER DISEASE-SPECIFIC MICROENVIRONMENTAL CONDITIONS. THE IMPACT OF PHASEVARION REGULATION WAS GREATEST UNDER ALKALINE CONDITIONS THAT MIMIC THOSE KNOWN TO OCCUR IN THE MIDDLE EAR DURING DISEASE. UNDER ALKALINE CONDITIONS, NTHI STRAINS THAT EXPRESS THE MODA2 METHYLTRANSFERASE FORMED BIOFILMS WITH SIGNIFICANTLY GREATER BIOMASS AND LESS DISTINCT ARCHITECTURE THAN THOSE FORMED BY A MODA2-DEFICIENT POPULATION. THE BIOFILMS FORMED BY NTHI STRAINS THAT EXPRESS MODA2 ALSO CONTAINED LESS EXTRACELLULAR DNA (EDNA) AND SIGNIFICANTLY LESS EXTRACELLULAR HU, A DNABII DNA-BINDING PROTEIN CRITICAL FOR BIOFILM STRUCTURAL STABILITY. STABLE BIOFILM STRUCTURE IS CRITICAL FOR BACTERIAL PATHOGENESIS AND PERSISTENCE IN MULTIPLE EXPERIMENTAL MODELS OF DISEASE. THESE RESULTS IDENTIFY A ROLE FOR THE PHASEVARION IN REGULATION OF BIOFILM FORMATION, A PROCESS INTEGRAL TO THE CHRONIC NATURE OF MANY INFECTIONS. UNDERSTANDING THE ROLE OF THE PHASEVARION IN BIOFILM FORMATION IS CRITICAL TO THE DEVELOPMENT OF PREVENTION AND TREATMENT STRATEGIES FOR THESE CHRONIC DISEASES.IMPORTANCE UPPER RESPIRATORY TRACT INFECTIONS ARE THE NUMBER ONE REASON FOR A CHILD TO VISIT THE EMERGENCY DEPARTMENT, AND OTITIS MEDIA (MIDDLE EAR INFECTION) RANKS THIRD OVERALL. BIOFILMS CONTRIBUTE SIGNIFICANTLY TO THE CHRONIC NATURE OF BACTERIAL RESPIRATORY TRACT INFECTIONS, INCLUDING OTITIS MEDIA, AND MAKE THESE DISEASES PARTICULARLY DIFFICULT TO TREAT. SEVERAL MUCOSA-ASSOCIATED HUMAN PATHOGENS UTILIZE A MECHANISM OF RAPID ADAPTATION TERMED THE PHASEVARION, OR PHASEVARIABLE REGULON, TO RESIST ENVIRONMENTAL AND HOST IMMUNE PRESSURES. IN THIS STUDY, WE ASSESSED THE ROLE OF THE PHASEVARION IN REGULATION OF BIOFILM FORMATION BY NONTYPEABLE HAEMOPHILUS INFLUENZAE (NTHI), WHICH CAUSES NUMEROUS RESPIRATORY TRACT DISEASES. WE FOUND THAT THE NTHI PHASEVARION REGULATES BIOFILM STRUCTURE AND CRITICAL BIOFILM MATRIX COMPONENTS UNDER DISEASE-SPECIFIC CONDITIONS. THE FINDINGS OF THIS WORK COULD BE SIGNIFICANT IN THE DESIGN OF IMPROVED STRATEGIES AGAINST NTHI INFECTIONS, AS WELL AS DISEASES DUE TO OTHER PATHOGENS THAT UTILIZE A PHASEVARION. 2018 9 4553 29 MUTATIONAL LANDSCAPE OF CHRONIC MYELOMONOCYTIC LEUKEMIA IN CHINESE PATIENTS. BACKGROUND: CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) IS A RARE AND HETEROGENEOUS HEMATOLOGICAL MALIGNANCY. IT HAS BEEN SHOWN THAT THE MOLECULAR ABNORMALITIES SUCH AS ASXL1, TET2, SETBP1, AND SRSF2 MUTATIONS ARE COMMON IN CAUCASIAN POPULATION. METHODS: WE RETROSPECTIVELY ANALYZED 178 CHINESE CMML PATIENTS. THE TARGETED NEXT GENERATION SEQUENCING (NGS) WAS USED TO EVALUATE 114 GENE VARIATIONS, AND THE PROGNOSTIC FACTORS FOR OS WERE DETERMINED BY COX REGRESSION ANALYSIS. RESULTS: THE CMML PATIENTS SHOWED A UNIQUE MUTATIONAL SPECTRUM, INCLUDING TET2 (36.5%), NRAS (31.5%), ASXL1 (28.7%), SRSF2 (24.7%), AND RUNX1 (21.9%). OF THE 102 PATIENTS WITH CLONAL ANALYSIS, THE ANCESTRAL EVENTS PREFERENTIALLY OCCURRED IN TET2 (18.5%), SPLICING FACTORS (16.5%), RAS (14.0%), AND ASXL1 (7.8%), AND THE SUBCLONAL GENES WERE MAINLY ASXL1, TET2, AND RAS. IN ADDITION, THE SECONDARY ACUTE MYELOID LEUKEMIA (SAML) TRANSFORMED FROM CMML OFTEN HAD MUTATIONS IN DNMT3A, ETV6, FLT3, AND NPM1, WHILE THE PRIMARY AML (PAML) DEMONSTRATED MORE MUTATIONS IN CEBPA, DNMT3A, FLT3, IDH1/2, NPM1, AND WT1. IT WAS OF NOTE THAT A SERIES OF CLONES WERE EMERGED DURING THE PROGRESSION FROM CMML TO AML, INCLUDING DNMT3A, FLT3, AND NPM1. BY UNIVARIATE ANALYSIS, ASXL1 MUTATION, INTERMEDIATE- AND HIGH-RISK CYTOGENETIC ABNORMALITY, CMML-SPECIFIC PROGNOSTIC SCORING SYSTEM (CPSS) STRATIFICATIONS (INTERMEDIATE-2 AND HIGH GROUP), AND TREATMENT OPTIONS (BEST SUPPORTIVE CARE) PREDICTED FOR WORSE OS. MULTIVARIATE ANALYSIS REVEALED A SIMILAR OUTCOME. CONCLUSIONS: THE COMMON MUTATIONS IN CHINESE CMML PATIENTS INCLUDED EPIGENETIC MODIFIERS (TET2 AND ASXL1), SIGNALING TRANSDUCTION PATHWAY COMPONENTS (NRAS), AND SPLICING FACTOR (SRSF2). THE CMML PATIENTS WITH DNMT3A, ETV6, FLT3, AND NPM1 MUTATIONS TENDED TO PROGRESS TO SAML. ASXL1 MUTATION AND THERAPEUTIC MODALITIES WERE INDEPENDENT PROGNOSTIC FACTORS FOR CMML. 2022 10 5790 32 SRSF2-P95 HOTSPOT MUTATION IS HIGHLY ASSOCIATED WITH ADVANCED FORMS OF MASTOCYTOSIS AND MUTATIONS IN EPIGENETIC REGULATOR GENES. MASTOCYTOSIS IS A RARE AND CHRONIC DISEASE WITH PHENOTYPES RANGING FROM INDOLENT TO SEVERE. PROGNOSIS FOR THIS DISEASE IS VARIABLE AND VERY FEW BIOMARKERS TO PREDICT DISEASE EVOLUTION OR OUTCOME ARE CURRENTLY KNOWN. WE HAVE PERFORMED COMPREHENSIVE SCREENING IN OUR LARGE COHORT OF MASTOCYTOSIS PATIENTS FOR MUTATIONS PREVIOUSLY FOUND IN OTHER MYELOID DISEASES AND THAT COULD SERVE AS PROGNOSTIC INDICATORS. KIT, SRSF2-P95 AND TET2 MUTATIONS WERE BY FAR THE MOST FREQUENT, DETECTED IN 81%, 24% AND 21% OF PATIENTS, RESPECTIVELY. WHERE TET2 AND SRSF2-P95 MUTATION BOTH CORRELATED WITH ADVANCED DISEASE PHENOTYPES, SRSF2-P95 HOTSPOT MUTATION WAS FOUND ALMOST EXCLUSIVELY IN PATIENTS DIAGNOSED WITH ASSOCIATED CLONAL HEMATOLOGIC NON-MAST CELL DISEASE. STATISTICALLY, TET2 AND SRSF2-P95 MUTATIONS WERE HIGHLY ASSOCIATED, SUGGESTING A MECHANISTIC LINK BETWEEN THESE TWO FACTORS. FINALLY, ANALYSIS OF BOTH CLONAL AND SORTED CELL POPULATIONS FROM PATIENTS CONFIRMS THE PRESENCE OF THESE MUTATIONS IN THE MAST CELL COMPONENT OF THE DISEASE, SUGGESTS AN ONTOLOGICAL MUTATION HIERARCHY AND PROVIDES EVIDENCE FOR THE EXPANSION OF MULTIPLE CLONES. THIS HIGHLIGHTS THE PROGNOSTIC POTENTIAL OF SUCH APPROACHES, IF APPLIED SYSTEMATICALLY, FOR DELINEATING THE ROLES OF SPECIFIC MUTATIONS IN PREDISPOSING AND/OR DRIVING DISTINCT DISEASE PHENOTYPES. 2014 11 959 26 CHRONIC MYELOMONOCYTIC LEUKEMIA AND ATYPICAL CHRONIC MYELOID LEUKEMIA: NOVEL PATHOGENETIC LESIONS. CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AND ATYPICAL CHRONIC MYELOID LEUKEMIA (ACML) ARE DISTINCT, YET RELATED, ENTITIES OF MYELODYSPLASTIC/MYELOPROLIFERATIVE NEOPLASMS (MDS/MPN) CHARACTERIZED BY MORPHOLOGIC DYSPLASIA WITH ACCUMULATION OF MONOCYTES OR NEUTROPHILS, RESPECTIVELY. OUR UNDERSTANDING OF THE MOLECULAR PATHOGENESIS OF CMML AND ACML HAS ADVANCED, MAINLY DUE TO THE APPLICATION OF NOVEL TECHNOLOGIES SUCH AS ARRAY-BASED KARYOTYPING AND NEXT-GENERATION SEQUENCING. IN ADDITION TO PREVIOUSLY KNOWN RECURRENT ABERRATIONS, SOMATIC UNIPARENTAL DISOMY AFFECTING CHROMOSOMES 3, 4, 7, AND 11 FREQUENTLY OCCURS IN CMML. NOVEL SOMATIC MUTATIONS OF GENES, INCLUDING THOSE ASSOCIATED WITH PROLIFERATION SIGNALING (CBL, RAS, RUNX1, JAK2 (V617F)) AND WITH MODIFICATION OF EPIGENETIC STATUS (TET2, ASXL1, UTX, EZH2) HAVE BEEN FOUND. VARIOUS COMBINATIONS OF MUTATIONS SUGGEST A MULTISTEP PATHOGENESIS AND MAY ACCOUNT FOR CLINICAL HETEROGENEITY. MOST RECENTLY, SEVERAL SPLICEOSOME-ASSOCIATED-GENE MUTATIONS WERE REPORTED AND SRSF2 MUTATIONS ARE FREQUENTLY DETECTED IN CMML. THE PROGNOSTIC AND DIAGNOSTIC SIGNIFICANCE OF THESE MOLECULAR LESIONS, IN PARTICULAR THEIR VALUE AS BIOMARKERS OF RESPONSE OR RESISTANCE TO SPECIFIC THERAPIES, WHILE UNCERTAIN NOW IS LIKELY TO BE CLARIFIED AS LARGE SYSTEMATIC STUDIES COME TO COMPLETION. 2012 12 129 30 A UNIQUE VIRULENCE GENE OCCUPIES A PRINCIPAL POSITION IN IMMUNE EVASION BY THE MALARIA PARASITE PLASMODIUM FALCIPARUM. MUTUALLY EXCLUSIVE GENE EXPRESSION, WHEREBY ONLY ONE MEMBER OF A MULTI-GENE FAMILY IS SELECTED FOR ACTIVATION, IS USED BY THE MALARIA PARASITE PLASMODIUM FALCIPARUM TO ESCAPE THE HUMAN IMMUNE SYSTEM AND PERPETUATE LONG-TERM, CHRONIC INFECTIONS. A FAMILY OF GENES CALLED VAR ENCODES THE CHIEF ANTIGENIC AND VIRULENCE DETERMINANT OF P. FALCIPARUM MALARIA. VAR GENES ARE TRANSCRIBED IN A MUTUALLY EXCLUSIVE MANNER, WITH SWITCHING BETWEEN ACTIVE GENES RESULTING IN ANTIGENIC VARIATION. WHILE RECENT WORK HAS SHED CONSIDERABLE LIGHT ON THE EPIGENETIC BASIS FOR VAR GENE ACTIVATION AND SILENCING, HOW SWITCHING IS CONTROLLED REMAINS A MYSTERY. IN PARTICULAR, SWITCHING SEEMS NOT TO BE RANDOM, BUT INSTEAD APPEARS TO BE COORDINATED TO RESULT IN TIMELY ACTIVATION OF INDIVIDUAL GENES LEADING TO SEQUENTIAL WAVES OF ANTIGENICALLY DISTINCT PARASITE POPULATIONS. THE MOLECULAR BASIS FOR THIS APPARENT COORDINATION IS UNKNOWN. HERE WE SHOW THAT VAR2CSA, AN UNUSUAL AND HIGHLY CONSERVED VAR GENE, OCCUPIES A UNIQUE POSITION WITHIN THE VAR GENE SWITCHING HIERARCHY. INDUCTION OF SWITCHING THROUGH THE DESTABILIZATION OF VAR SPECIFIC CHROMATIN USING BOTH GENETIC AND CHEMICAL METHODS REPEATEDLY LED TO THE RAPID AND EXCLUSIVE ACTIVATION OF VAR2CSA. ADDITIONAL EXPERIMENTS DEMONSTRATED THAT THESE REPRESENT "TRUE" SWITCHING EVENTS AND NOT SIMPLY DE-SILENCING OF THE VAR2CSA PROMOTER, AND THAT ACTIVATION IS LIMITED TO THE UNIQUE LOCUS ON CHROMOSOME 12. COMBINED WITH TRANSLATIONAL REPRESSION OF VAR2CSA TRANSCRIPTS, FREQUENT "DEFAULT" SWITCHING TO THIS LOCUS AND DETECTION OF VAR2CSA UNTRANSLATED TRANSCRIPTS IN NON-PREGNANT INDIVIDUALS, THESE DATA SUGGEST THAT VAR2CSA COULD PLAY A CENTRAL ROLE IN COORDINATING SWITCHING, FULFILLING A PREDICTION MADE BY MATHEMATICAL MODELS DERIVED FROM POPULATION SWITCHING PATTERNS. THESE STUDIES PROVIDE THE FIRST INSIGHTS INTO THE MECHANISMS BY WHICH VAR GENE SWITCHING IS COORDINATED AS WELL AS AN EXAMPLE OF HOW A PHARMACOLOGICAL AGENT CAN DISRUPT ANTIGENIC VARIATION IN PLASMODIUM FALCIPARUM. 2015 13 1720 21 DYSREGULATED N6-METHYLADENOSINE (M(6)A) PROCESSING IN HEPATOCELLULAR CARCINOMA. N6-METHYLADENOSINE (M(6)A) IS THE MOST THOROUGHLY STUDIED TYPE OF INTERNAL RNA MODIFICATION, AS THIS EPIGENETIC MODIFICATION IS THE MOST ABUNDANT IN EUKARYOTIC RNAS TO DATE. THIS MODIFICATION OCCURS IN VARIOUS TYPES OF RNAS AND PLAYS SIGNIFICANT ROLES IN DOMINANT RNA-RELATED PROCESSES, SUCH AS TRANSLATION, SPLICING, EXPORT AND DEGRADATION. THESE PROCESSES ARE CATALYZED BY THREE TYPES OF PROMINENT ENZYMES: WRITERS, ERASERS AND READERS. INCREASING EVIDENCE HAS SHOWN THAT M(6)A MODIFICATION IS VITAL FOR THE REGULATION OF GENE EXPRESSION, CARCINOGENESIS, TUMOR PROGRESSION AND OTHER ABNORMAL CHANGES, AND RECENT STUDIES HAVE SHOWN THAT M(6)A IS IMPORTANT IN THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC). HEREIN, WE SUMMARIZE THE NATURE AND REGULATORY MECHANISMS OF M(6)A MODIFICATION, INCLUDING ITS ROLE IN THE PATHOGENESIS OF HCC AND RELATED CHRONIC LIVER DISEASES. WE ALSO HIGHLIGHT THE CLINICAL SIGNIFICANCE AND FUTURE STRATEGIES INVOLVING RNA M(6)A MODIFICATIONS IN HCC. 2021 14 5246 28 PROGNOSTIC SCORE INCLUDING GENE MUTATIONS IN CHRONIC MYELOMONOCYTIC LEUKEMIA. PURPOSE: SEVERAL PROGNOSTIC SCORING SYSTEMS HAVE BEEN PROPOSED FOR CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), A DISEASE IN WHICH SOME GENE MUTATIONS-INCLUDING ASXL1-HAVE BEEN ASSOCIATED WITH POOR PROGNOSIS IN UNIVARIABLE ANALYSES. WE DEVELOPED AND VALIDATED A PROGNOSTIC SCORE FOR OVERALL SURVIVAL (OS) BASED ON MUTATIONAL STATUS AND STANDARD CLINICAL VARIABLES. PATIENTS AND METHODS: WE GENOTYPED ASXL1 AND UP TO 18 OTHER GENES INCLUDING EPIGENETIC (TET2, EZH2, IDH1, IDH2, DNMT3A), SPLICING (SF3B1, SRSF2, ZRSF2, U2AF1), TRANSCRIPTION (RUNX1, NPM1, TP53), AND SIGNALING (NRAS, KRAS, CBL, JAK2, FLT3) REGULATORS IN 312 PATIENTS WITH CMML. GENOTYPES AND CLINICAL VARIABLES WERE INCLUDED IN A MULTIVARIABLE COX MODEL OF OS VALIDATED BY BOOTSTRAPPING. A SCORING SYSTEM WAS DEVELOPED USING REGRESSION COEFFICIENTS FROM THIS MODEL. RESULTS: ASXL1 MUTATIONS (P < .0001) AND, TO A LESSER EXTENT, SRSF2 (P = .03), CBL (P = .003), AND IDH2 (P = .03) MUTATIONS PREDICTED INFERIOR OS IN UNIVARIABLE ANALYSIS. THE RETAINED INDEPENDENT PROGNOSTIC FACTORS INCLUDED ASXL1 MUTATIONS, AGE OLDER THAN 65 YEARS, WBC COUNT GREATER THAN 15 X10(9)/L, PLATELET COUNT LESS THAN 100 X10(9)/L, AND ANEMIA (HEMOGLOBIN < 10 G/DL IN FEMALE PATIENTS, < 11G/DL IN MALE PATIENTS). THE RESULTING FIVE-PARAMETER PROGNOSTIC SCORE DELINEATED THREE GROUPS OF PATIENTS WITH MEDIAN OS NOT REACHED, 38.5 MONTHS, AND 14.4 MONTHS, RESPECTIVELY (P < .0001), AND WAS VALIDATED IN AN INDEPENDENT COHORT OF 165 PATIENTS (P < .0001). CONCLUSION: A NEW PROGNOSTIC SCORE INCLUDING ASXL1 STATUS, AGE, HEMOGLOBIN, WBC, AND PLATELET COUNTS DEFINES THREE GROUPS OF CMML PATIENTS WITH DISTINCT OUTCOMES. BASED ON CONCORDANCE ANALYSIS, THIS SCORE APPEARS MORE DISCRIMINATIVE THAN THOSE BASED SOLELY ON CLINICAL PARAMETERS. 2013 15 4565 18 MYELOID MALIGNANCIES: MUTATIONS, MODELS AND MANAGEMENT. MYELOID MALIGNANT DISEASES COMPRISE CHRONIC (INCLUDING MYELODYSPLASTIC SYNDROMES, MYELOPROLIFERATIVE NEOPLASMS AND CHRONIC MYELOMONOCYTIC LEUKEMIA) AND ACUTE (ACUTE MYELOID LEUKEMIA) STAGES. THEY ARE CLONAL DISEASES ARISING IN HEMATOPOIETIC STEM OR PROGENITOR CELLS. MUTATIONS RESPONSIBLE FOR THESE DISEASES OCCUR IN SEVERAL GENES WHOSE ENCODED PROTEINS BELONG PRINCIPALLY TO FIVE CLASSES: SIGNALING PATHWAYS PROTEINS (E.G. CBL, FLT3, JAK2, RAS), TRANSCRIPTION FACTORS (E.G. CEBPA, ETV6, RUNX1), EPIGENETIC REGULATORS (E.G. ASXL1, DNMT3A, EZH2, IDH1, IDH2, SUZ12, TET2, UTX), TUMOR SUPPRESSORS (E.G. TP53), AND COMPONENTS OF THE SPLICEOSOME (E.G. SF3B1, SRSF2). LARGE-SCALE SEQUENCING EFFORTS WILL SOON LEAD TO THE ESTABLISHMENT OF A COMPREHENSIVE REPERTOIRE OF THESE MUTATIONS, ALLOWING FOR A BETTER DEFINITION AND CLASSIFICATION OF MYELOID MALIGNANCIES, THE IDENTIFICATION OF NEW PROGNOSTIC MARKERS AND THERAPEUTIC TARGETS, AND THE DEVELOPMENT OF NOVEL THERAPIES. GIVEN THE IMPORTANCE OF EPIGENETIC DEREGULATION IN MYELOID DISEASES, THE USE OF DRUGS TARGETING EPIGENETIC REGULATORS APPEARS AS A MOST PROMISING THERAPEUTIC APPROACH. 2012 16 2678 26 EVALUATION OF A PROGNOSTIC EPIGENETIC CLASSIFICATION SYSTEM IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS. BACKGROUND: METHYLATION AT 5 CPG SITES WAS PREVIOUSLY SHOWN TO CLASSIFY CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) INTO 3 PROGNOSTIC SUBGROUPS. HERE, WE AIMED TO VALIDATE THE MARKER SET IN AN ADDITIONAL COHORT AND TO EVALUATE ITS CLINICAL UTILITY FOR CLL PATIENT STRATIFICATION. METHODS: WE EVALUATED THIS EPIGENETIC MARKER SET IN 79 GERMAN PATIENTS USING BISULFITE TREATMENT FOLLOWED BY PYROSEQUENCING AND CLASSIFICATION USING A SUPPORT VECTOR MACHINE-LEARNING TOOL. RESULTS: THE N-CLL, I-CLL, AND M-CLL CLASSIFICATION WAS DETECTED IN 28 (35%), 10 (13%), AND 41 (51%) PATIENTS, RESPECTIVELY. EPIGENETIC GROUPING WAS ASSOCIATED WITH IGHV MUTATIONAL STATUS (P = 2 X 10(-12)), ISOLATED DEL13Q (P = 9 X 10(-6)), DEL17P (P = .015), COMPLEX KARYOTYPE (P = .005), VH-USAGE, AND CLINICAL OUTCOME AS TIME TO FIRST TREATMENT (P = 1.4 X 10(-12)) AND OVERALL SURVIVAL (P = .003). MULTIVARIATE COX REGRESSION ANALYSIS IDENTIFIED N-CLL AS A FACTOR FOR EARLIER TREATMENT HAZARD RATIO (HR), 6.3 (95% CONFIDENCE INTERVAL [CI] 2.4-16.4; P = .0002) COMPARED TO IGHV MUTATIONAL STATUS (HR 4.6, 95% CI 1.9-11.3, P = .0008). IN ADDITION, WHEN COMPARING THE PROGNOSTIC VALUE OF THE EPIGENETIC CLASSIFICATION SYSTEM WITH THE IGHV CLASSIFICATION, EPIGENETIC GROUPING PERFORMED BETTER COMPARED TO IGHV MUTATIONAL STATUS USING KAPLAN-MEIER ESTIMATION AND ALLOWED THE IDENTIFICATION OF A THIRD, INTERMEDIATE (I-CLL) GROUP. THUS, OUR STUDY CONFIRMED THE PROGNOSTIC VALUE OF THE EPIGENETIC MARKER SET FOR PATIENT STRATIFICATION IN ROUTINE CLINICAL DIAGNOSTICS. 2022 17 5980 25 TET2 MUTATIONS WERE PREDICTIVE OF INFERIOR PROGNOSIS IN THE PRESENCE OF ASXL1 MUTATIONS IN PATIENTS WITH CHRONIC MYELOMONOCYTIC LEUKEMIA. BACKGROUND: SOMATIC MUTATIONS INVOLVING EPIGENETIC REGULATORS, HISTONE MODIFICATION AND CHROMATIN REGULATION, SPLICING COMPONENTS, TRANSCRIPTION FACTORS AND SIGNALING REGULATOR GENES ARE COMMON IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) PATIENTS. IT HAS BEEN CONSENSUS THAT ASXL1 MUTATIONS HAVE ADVERSELY IMPACT ON OVERALL SURVIVAL (OS), WHILE THE EFFECT OF TET2 MUTATIONS REMAINS CONTROVERSIAL AND UNDEFINED. METHODS: ASXL1 AND TET2 MUTATIONS WERE ANALYZED IN 141 PATIENTS WITH CMML USING SANGER SEQUENCING, WITH THE AIM TO IDENTIFY THE INTERPLAY OF ASXL1 AND TET2 MUTATIONS IN THE PROGNOSIS OF CMML. RESULTS: SIXTY-FIVE (46.1%) OF THE CMML PATIENTS HARBORED ASXL1 MUTATIONS (FRAMESHIFT AND NONSENSE), AND 46 (32.6%) HAD TET2 MUTATIONS (FRAME SHIFT, NONSENSE AND MISSENSE). IN A SEPARATE MULTIVARIABLE ANALYSIS THAT INCLUDED THE MAYO PROGNOSTIC MODEL AS A SINGLE VARIABLE ALONG WITH ASXL1WT/TET2WT, THE RESPECTIVE HAZARD RATIOS OF ASXL1MUT/TET2MUT, ASXL1MUT/TET2WT AND ASXL1WT/TET2MUT WERE 4.7 (95% CI, 2.2-10.3; P<0.001), 2.2 (95% CI, 1.1-4.2; P=0.025) AND 1.3 (95% CI, 0.6-2.5; P=0.521). CONCLUSIONS: OUR STUDY SHOWED THAT ASXL1 MUTATIONS PREDICT INFERIOR OS, AND ADDITIONAL TET2 MUTATIONS WERE ASSOCIATED WITH POOR SURVIVAL IN THE PRESENCE OF ASXL1 MUTATIONS OF CMML PATIENTS. 2016 18 4395 34 MODM DNA METHYLTRANSFERASE METHYLOME ANALYSIS REVEALS A POTENTIAL ROLE FOR MORAXELLA CATARRHALIS PHASEVARIONS IN OTITIS MEDIA. MORAXELLA CATARRHALIS IS A SIGNIFICANT CAUSE OF OTITIS MEDIA AND EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. HERE, WE CHARACTERIZE A PHASE-VARIABLE DNA METHYLTRANSFERASE (MODM), WHICH CONTAINS 5'-CAAC-3' REPEATS IN ITS OPEN READING FRAME THAT MEDIATE HIGH-FREQUENCY MUTATION RESULTING IN REVERSIBLE ON/OFF SWITCHING OF MODM EXPRESSION. THREE MODM ALLELES HAVE BEEN IDENTIFIED (MODM1-3), WITH MODM2 BEING THE MOST COMMONLY FOUND ALLELE. USING SINGLE-MOLECULE, REAL-TIME (SMRT) GENOME SEQUENCING AND METHYLOME ANALYSIS, WE HAVE DETERMINED THAT THE MODM2 METHYLATION TARGET IS 5'-GAR(M6)AC-3', AND 100% OF THESE SITES ARE METHYLATED IN THE GENOME OF THE M. CATARRHALIS 25239 MODM2 ON STRAIN. PROTEOMIC ANALYSIS OF MODM2 ON AND OFF VARIANTS REVEALED THAT MODM2 REGULATES EXPRESSION OF MULTIPLE GENES THAT HAVE POTENTIAL ROLES IN COLONIZATION, INFECTION, AND PROTECTION AGAINST HOST DEFENSES. INVESTIGATION OF THE DISTRIBUTION OF MODM ALLELES IN A PANEL OF M. CATARRHALIS STRAINS, ISOLATED FROM THE NASOPHARYNX OF HEALTHY CHILDREN OR MIDDLE EAR EFFUSIONS FROM PATIENTS WITH OTITIS MEDIA, REVEALED A STATISTICALLY SIGNIFICANT ASSOCIATION OF MODM3 WITH OTITIS MEDIA ISOLATES. THE MODULATION OF GENE EXPRESSION VIA THE MODM PHASE-VARIABLE REGULON (PHASEVARION), AND THE SIGNIFICANT ASSOCIATION OF THE MODM3 ALLELE WITH OTITIS MEDIA, SUGGESTS A KEY ROLE FOR MODM PHASEVARIONS IN THE PATHOGENESIS OF THIS ORGANISM. 2014 19 4884 23 OVERVIEW OF THE PATHOGENESIS, GENETIC, AND NON-INVASIVE CLINICAL, BIOCHEMICAL, AND SCORING METHODS IN THE ASSESSMENT OF NAFLD. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS THE MOST PREVALENT CHRONIC LIVER DISEASE WORLDWIDE. IT REPRESENTS A RANGE OF DISORDERS, INCLUDING SIMPLE STEATOSIS, NONALCOHOLIC STEATOHEPATITIS (NASH), AND LIVER CIRRHOSIS, AND ITS PREVALENCE CONTINUES TO RISE. IN SOME CASES, HEPATOCELLULAR CARCINOMA (HCC) MAY DEVELOP. THE DEVELOP;MENT OF NON-INVASIVE DIAGNOSTIC AND SCREENING TOOLS IS NEEDED, IN ORDER TO REDUCE THE FREQUENCY OF LIVER BIOPSIES. THE MOST PROMISING METHODS ARE THOSE ABLE TO EXCLUDE ADVANCED FIBROSIS AND QUANTIFY STEATOSIS. IN THIS STUDY, NEW PERSPECTIVE MARKERS FOR INFLAMMATION, OXIDATIVE STRESS, APOPTOSIS, AND FIBROGENESIS; EMERGING SCORING MODELS FOR DETECTING HEPATIC STEATOSIS AND FIBROSIS; AND NEW GENETIC, EPIGENETIC, AND MULTIOMIC STUDIES ARE DISCUSSED. AS ISOLATED BIOCHEMICAL PARAMETERS ARE NOT SPECIFIC OR SENSITIVE ENOUGH TO PREDICT THE PRESENCE OF NASH AND FIBROSIS, THERE IS A TENDENCY TO USE VARIOUS MARKERS AND COMBINE THEM INTO MATHEMATICAL ALGORITHMS. SEVERAL PREDICTIVE MODELS AND SCORING SYSTEMS HAVE BEEN DEVELOPED. CURRENT DATA SUGGESTS THAT PANELS OF MARKERS (NAFLD FIBROSIS SCORE, FIB-4 SCORE, BARD SCORE, AND OTHERS) ARE USEFUL DIAGNOSTIC MODALITIES TO MINIMIZE THE NUMBER OF LIVER BIOPSIES. THE REVIEW UNVEILS PATHOPHYSIOLOGICAL ASPECTS RELATED TO NEW TRENDS IN CURRENT NON-INVASIVE BIOCHEMICAL, GENETIC, AND SCORING METHODS, AND PROVIDES INSIGHT INTO THEIR DIAGNOSTIC ACCURACIES AND SUITABILITY IN CLINICAL PRACTICE. 2019 20 6144 25 THE EVOLVING LANDSCAPE OF N(6)-METHYLADENOSINE MODIFICATION IN THE TUMOR MICROENVIRONMENT. THE TUMOR MICROENVIRONMENT (TME), CONTROLLED BY INTRINSIC MECHANISMS OF CARCINOGENESIS AND EPIGENETIC MODIFICATIONS, HAS, IN RECENT YEARS, BECOME A HEAVILY RESEARCHED TOPIC. THE TME CAN BE DESCRIBED IN TERMS OF HYPOXIA, METABOLIC DYSREGULATION, IMMUNE ESCAPE, AND CHRONIC INFLAMMATION. RNA METHYLATION, AN EPIGENETIC MODIFICATION, HAS RECENTLY BEEN FOUND TO HAVE A PIVOTAL ROLE IN SHAPING THE TME. THE N(6)-METHYLATION OF ADENOSINE (M(6)A) MODIFICATION IS THE MOST COMMON TYPE OF RNA METHYLATION THAT OCCURS IN THE N(6)-POSITION OF ADENOSINE, WHICH IS THE PRIMARY INTERNAL MODIFICATION OF EUKARYOTIC MRNA. COMPELLING EVIDENCE HAS DEMONSTRATED THAT M(6)A REGULATES TRANSCRIPTIONAL AND PROTEIN EXPRESSION THROUGH SPLICING, TRANSLATION, DEGRADATION, AND EXPORT, THEREBY MEDIATING THE BIOLOGICAL PROCESSES OF CANCER CELLS AND/OR STROMAL CELLS AND CHARACTERIZING THE TME. THE TME ALSO HAS A CRUCIAL ROLE IN THE COMPLICATED REGULATORY NETWORK OF M(6)A MODIFICATIONS AND, SUBSEQUENTLY, INFLUENCES TUMOR INITIATION, PROGRESSION, AND THERAPY RESPONSES. IN THIS REVIEW, WE DESCRIBE THE FEATURES OF THE TME AND HOW THE M(6)A MODIFICATION MODULATES AND INTERACTS WITH IT. WE ALSO FOCUS ON VARIOUS FACTORS AND PATHWAYS INVOLVED IN M(6)A METHYLATION. FINALLY, WE DISCUSS POTENTIAL THERAPEUTIC STRATEGIES AND PROGNOSTIC BIOMARKERS WITH RESPECT TO THE TME AND M(6)A MODIFICATION. 2021