1 1219 192 CRISPR/CAS9 GENOME EDITING REVEALS THAT THE INTRON IS NOT ESSENTIAL FOR VAR2CSA GENE ACTIVATION OR SILENCING IN PLASMODIUM FALCIPARUM. PLASMODIUM FALCIPARUM RELIES ON MONOALLELIC EXPRESSION OF 1 OF 60 VAR VIRULENCE GENES FOR ANTIGENIC VARIATION AND HOST IMMUNE EVASION. EACH VAR GENE CONTAINS A CONSERVED INTRON WHICH HAS BEEN IMPLICATED IN PREVIOUS STUDIES IN BOTH ACTIVATION AND REPRESSION OF TRANSCRIPTION VIA SEVERAL EPIGENETIC MECHANISMS, INCLUDING INTERACTION WITH THE VAR PROMOTER, PRODUCTION OF LONG NONCODING RNAS (LNCRNAS), AND LOCALIZATION TO REPRESSIVE PERINUCLEAR SITES. HOWEVER, FUNCTIONAL STUDIES HAVE RELIED PRIMARILY ON ARTIFICIAL EXPRESSION CONSTRUCTS. USING THE RECENTLY DEVELOPED P. FALCIPARUM CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR)/CAS9 SYSTEM, WE DIRECTLY DELETED THE VAR2CSA P. FALCIPARUM 3D7_1200600 (PF3D7_1200600) ENDOGENOUS INTRON, RESULTING IN AN INTRONLESS VAR GENE IN A NATURAL, MARKER-FREE CHROMOSOMAL CONTEXT. DELETION OF THE VAR2CSA INTRON RESULTED IN AN UPREGULATION OF TRANSCRIPTION OF THE VAR2CSA GENE IN RING-STAGE PARASITES AND SUBSEQUENT EXPRESSION OF THE PFEMP1 PROTEIN IN LATE-STAGE PARASITES. INTRON DELETION DID NOT AFFECT THE NORMAL TEMPORAL REGULATION AND SUBSEQUENT TRANSCRIPTIONAL SILENCING OF THE VAR GENE IN TROPHOZOITES BUT DID RESULT IN INCREASED RATES OF VAR GENE SWITCHING IN SOME MUTANT CLONES. TRANSCRIPTIONAL REPRESSION OF THE INTRONLESS VAR2CSA GENE COULD BE ACHIEVED VIA LONG-TERM CULTURE OR PANNING WITH THE CD36 RECEPTOR, AFTER WHICH REACTIVATION WAS POSSIBLE WITH CHONDROITIN SULFATE A (CSA) PANNING. THESE DATA SUGGEST THAT THE VAR2CSA INTRON IS NOT REQUIRED FOR SILENCING OR ACTIVATION IN RING-STAGE PARASITES BUT POINT TO A SUBTLE ROLE IN REGULATION OF SWITCHING WITHIN THE VAR GENE FAMILY.IMPORTANCEPLASMODIUM FALCIPARUM IS THE MOST VIRULENT SPECIES OF MALARIA PARASITE, CAUSING HIGH RATES OF MORBIDITY AND MORTALITY IN THOSE INFECTED. CHRONIC INFECTION DEPENDS ON AN IMMUNE EVASION MECHANISM TERMED ANTIGENIC VARIATION, WHICH IN TURN RELIES ON MONOALLELIC EXPRESSION OF 1 OF ~60 VAR GENES. UNDERSTANDING ANTIGENIC VARIATION AND THE TRANSCRIPTIONAL REGULATION OF MONOALLELIC EXPRESSION IS IMPORTANT FOR DEVELOPING DRUGS AND/OR VACCINES. THE VAR GENE FAMILY ENCODES THE ANTIGENIC SURFACE PROTEINS THAT DECORATE INFECTED ERYTHROCYTES. UNTIL RECENTLY, STUDYING THE UNDERLYING GENETIC ELEMENTS THAT REGULATE MONOALLELIC EXPRESSION IN P. FALCIPARUM WAS DIFFICULT, AND MOST STUDIES RELIED ON ARTIFICIAL SYSTEMS SUCH AS EPISOMAL REPORTER GENES. OUR STUDY WAS THE FIRST TO USE CRISPR/CAS9 GENOME EDITING FOR THE FUNCTIONAL STUDY OF AN IMPORTANT, CONSERVED GENETIC ELEMENT OF VAR GENES-THE INTRON-IN AN ENDOGENOUS, EPISOME-FREE MANNER. OUR FINDINGS SHED LIGHT ON THE ROLE OF THE VAR GENE INTRON IN TRANSCRIPTIONAL REGULATION OF MONOALLELIC EXPRESSION. 2017 2 3062 39 GENOME-WIDE DNA METHYLATION ANALYSIS REVEALS NOVEL EPIGENETIC CHANGES IN CHRONIC LYMPHOCYTIC LEUKEMIA. WE CONDUCTED A GENOME-WIDE DNA METHYLATION ANALYSIS IN CD19 (+) B-CELLS FROM CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) PATIENTS AND NORMAL CONTROL SAMPLES USING REDUCED REPRESENTATION BISULFITE SEQUENCING (RRBS). THE METHYLATION STATUS OF 1.8-2.3 MILLION CPGS IN THE CLL GENOME WAS DETERMINED; ABOUT 45% OF THESE CPGS WERE LOCATED IN MORE THAN 23,000 CPG ISLANDS (CGIS). WHILE GLOBAL CPG METHYLATION WAS SIMILAR BETWEEN CLL AND NORMAL B-CELLS, 1764 GENE PROMOTERS WERE IDENTIFIED AS BEING DIFFERENTIALLY METHYLATED IN AT LEAST ONE CLL SAMPLE WHEN COMPARED WITH NORMAL B-CELL SAMPLES. NINETEEN PERCENT OF THE DIFFERENTIALLY METHYLATED GENES WERE INVOLVED IN TRANSCRIPTIONAL REGULATION. ABERRANT HYPERMETHYLATION WAS FOUND IN ALL HOX GENE CLUSTERS AND A SIGNIFICANT NUMBER OF WNT SIGNALING PATHWAY GENES. HYPOMETHYLATION OCCURRED MORE FREQUENTLY IN THE GENE BODY INCLUDING INTRONS, EXONS, AND 3'-UTRS IN CLL. THE NFATC1 P2 PROMOTER AND FIRST INTRON WAS FOUND TO BE HYPOMETHYLATED AND CORRELATED WITH UPREGULATION OF BOTH NFATC1 RNA AND PROTEIN EXPRESSION LEVELS IN CLL SUGGESTING THAT AN EPIGENETIC MECHANISM IS INVOLVED IN THE CONSTITUTIVE ACTIVATION OF NFAT ACTIVITY IN CLL CELLS. THIS COMPREHENSIVE DNA METHYLATION ANALYSIS WILL FURTHER OUR UNDERSTANDING OF THE EPIGENETIC CONTRIBUTION TO CELLULAR DYSFUNCTION IN CLL. 2012 3 40 46 A COMPARISON OF HERPES SIMPLEX VIRUS TYPE 1 AND VARICELLA-ZOSTER VIRUS LATENCY AND REACTIVATION. HERPES SIMPLEX VIRUS TYPE 1 (HSV-1; HUMAN HERPESVIRUS 1) AND VARICELLA-ZOSTER VIRUS (VZV; HUMAN HERPESVIRUS 3) ARE HUMAN NEUROTROPIC ALPHAHERPESVIRUSES THAT CAUSE LIFELONG INFECTIONS IN GANGLIA. FOLLOWING PRIMARY INFECTION AND ESTABLISHMENT OF LATENCY, HSV-1 REACTIVATION TYPICALLY RESULTS IN HERPES LABIALIS (COLD SORES), BUT CAN OCCUR FREQUENTLY ELSEWHERE ON THE BODY AT THE SITE OF PRIMARY INFECTION (E.G. WHITLOW), PARTICULARLY AT THE GENITALS. RARELY, HSV-1 REACTIVATION CAN CAUSE ENCEPHALITIS; HOWEVER, A THIRD OF THE CASES OF HSV-1 ENCEPHALITIS ARE ASSOCIATED WITH HSV-1 PRIMARY INFECTION. PRIMARY VZV INFECTION CAUSES VARICELLA (CHICKENPOX) FOLLOWING WHICH LATENT VIRUS MAY REACTIVATE DECADES LATER TO PRODUCE HERPES ZOSTER (SHINGLES), AS WELL AS AN INCREASINGLY RECOGNIZED NUMBER OF SUBACUTE, ACUTE AND CHRONIC NEUROLOGICAL CONDITIONS. FOLLOWING PRIMARY INFECTION, BOTH VIRUSES ESTABLISH A LATENT INFECTION IN NEURONAL CELLS IN HUMAN PERIPHERAL GANGLIA. HOWEVER, THE DETAILED MECHANISMS OF VIRAL LATENCY AND REACTIVATION HAVE YET TO BE UNRAVELLED. IN BOTH CASES LATENT VIRAL DNA EXISTS IN AN 'END-LESS' STATE WHERE THE ENDS OF THE VIRUS GENOME ARE JOINED TO FORM STRUCTURES CONSISTENT WITH UNIT LENGTH EPISOMES AND CONCATEMERS, FROM WHICH VIRAL GENE TRANSCRIPTION IS RESTRICTED. IN LATENTLY INFECTED GANGLIA, THE MOST ABUNDANTLY DETECTED HSV-1 RNAS ARE THE SPLICED PRODUCTS ORIGINATING FROM THE PRIMARY LATENCY ASSOCIATED TRANSCRIPT (LAT). THIS PRIMARY LAT IS AN 8.3 KB UNSTABLE TRANSCRIPT FROM WHICH TWO STABLE (1.5 AND 2.0 KB) INTRONS ARE SPLICED. TRANSCRIPTS MAPPING TO 12 VZV GENES HAVE BEEN DETECTED IN HUMAN GANGLIA REMOVED AT AUTOPSY; HOWEVER, IT IS DIFFICULT TO ASCRIBE THESE AS TRANSCRIPTS PRESENT DURING LATENT INFECTION AS EARLY-STAGE VIRUS REACTIVATION MAY HAVE TRANSPIRED IN THE POST-MORTEM TIME PERIOD IN THE GANGLIA. NONETHELESS, LOW-LEVEL TRANSCRIPTION OF VZV ORF63 HAS BEEN REPEATEDLY DETECTED IN MULTIPLE GANGLIA REMOVED AS CLOSE TO DEATH AS POSSIBLE. THERE IS INCREASING EVIDENCE THAT HSV-1 AND VZV LATENCY IS EPIGENETICALLY REGULATED. IN VITRO MODELS THAT PERMIT PATHWAY ANALYSIS AND IDENTIFICATION OF BOTH EPIGENETIC MODULATIONS AND GLOBAL TRANSCRIPTIONAL MECHANISMS OF HSV-1 AND VZV LATENCY HOLD MUCH PROMISE FOR OUR FUTURE UNDERSTANDING IN THIS COMPLEX AREA. THIS REVIEW SUMMARIZES THE MOLECULAR BIOLOGY OF HSV-1 AND VZV LATENCY AND REACTIVATION, AND ALSO PRESENTS FUTURE DIRECTIONS FOR STUDY. 2015 4 66 37 A KEY ROLE FOR EZH2 IN EPIGENETIC SILENCING OF HOX GENES IN MANTLE CELL LYMPHOMA. THE CHROMATIN MODIFIER EZH2 IS OVEREXPRESSED AND ASSOCIATED WITH INFERIOR OUTCOME IN MANTLE CELL LYMPHOMA (MCL). RECENTLY, WE DEMONSTRATED PREFERENTIAL DNA METHYLATION OF HOX GENES IN MCL COMPARED WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), DESPITE THESE GENES NOT BEING EXPRESSED IN EITHER ENTITY. SINCE EZH2 HAS BEEN SHOWN TO REGULATE HOX GENE EXPRESSION, TO GAIN FURTHER INSIGHT INTO ITS POSSIBLE ROLE IN DIFFERENTIAL SILENCING OF HOX GENES IN MCL VS. CLL, WE PERFORMED DETAILED EPIGENETIC CHARACTERIZATION USING REPRESENTATIVE CELL LINES AND PRIMARY SAMPLES. WE OBSERVED SIGNIFICANT OVEREXPRESSION OF EZH2 IN MCL VS. CLL. CHROMATIN IMMUNE PRECIPITATION (CHIP) ASSAYS REVEALED THAT EZH2 CATALYZED REPRESSIVE H3 LYSINE 27 TRIMETHYLATION (H3K27ME3), WHICH WAS SUFFICIENT TO SILENCE HOX GENES IN CLL, WHEREAS IN MCL H3K27ME3 IS ACCOMPANIED BY DNA METHYLATION FOR A MORE STABLE REPRESSION. MORE IMPORTANTLY, HYPERMETHYLATION OF THE HOX GENES IN MCL RESULTED FROM EZH2 OVEREXPRESSION AND SUBSEQUENT RECRUITMENT OF THE DNA METHYLATION MACHINERY ONTO HOX GENE PROMOTERS. THE IMPORTANCE OF EZH2 UPREGULATION IN THIS PROCESS WAS FURTHER UNDERSCORED BY SIRNA TRANSFECTION AND EZH2 INHIBITOR EXPERIMENTS. ALTOGETHER, THESE OBSERVATIONS IMPLICATE EZH2 IN THE LONG-TERM SILENCING OF HOX GENES IN MCL, AND ALLUDE TO ITS POTENTIAL AS A THERAPEUTIC TARGET WITH CLINICAL IMPACT. 2013 5 4947 32 PATERNAL SEPSIS INDUCES ALTERATIONS OF THE SPERM METHYLOME AND DAMPENS OFFSPRING IMMUNE RESPONSES-AN ANIMAL STUDY. BACKGROUND: SEPSIS REPRESENTS THE UTMOST SEVERE CONSEQUENCE OF INFECTION, INVOLVING A DYSREGULATED AND SELF-DAMAGING IMMUNE RESPONSE OF THE HOST. WHILE DIFFERENT ENVIRONMENTAL EXPOSURES LIKE CHRONIC STRESS OR MALNUTRITION HAVE BEEN WELL DESCRIBED TO REPROGRAM THE GERMLINE AND SUBSEQUENTLY OFFSPRING ATTRIBUTES, THE INTERGENERATIONAL IMPACT OF SEPSIS AS A TREMENDOUS IMMUNOLOGICAL STRESSOR HAS NOT BEEN EXAMINED YET. METHODS: POLYMICROBIAL SEPSIS IN 12-WEEK-OLD MALE C57BL/6 MICE WAS INDUCED BY CECAL LIGATION AND PUNCTURE (CLP), FOLLOWED BY A MATING OF THE MALE SURVIVORS (OR APPROPRIATE SHAM CONTROL ANIMALS) 6 WEEKS LATER WITH HEALTHY FEMALES. ALVEOLAR MACROPHAGES OF OFFSPRING ANIMALS WERE ISOLATED AND STIMULATED WITH EITHER LPS OR ZYMOSAN, AND SUPERNATANT LEVELS OF TNF-ALPHA WERE QUANTIFIED BY ELISA. FURTHERMORE, SYSTEMIC CYTOKINE RESPONSE TO INTRAPERITONEALLY INJECTED LPS WAS ASSESSED AFTER 24 H. ALSO, MORPHOLOGY, MOTILITY, AND GLOBAL DNA METHYLATION OF THE SEPSIS SURVIVORS' SPERM WAS EXAMINED. RESULTS: COMPARATIVE REDUCED REDUCTION BISULFITE SEQUENCING (RRBS) OF SPERM REVEALED CHANGES OF DNA METHYLATION (N = 381), MOST PRONOUNCED IN THE INTERGENIC GENOME AS WELL AS WITHIN INTRONS OF DEVELOPMENTALLY RELEVANT GENES. OFFSPRING OF SEPSIS FATHERS EXHIBITED A SLIGHT DECREASE IN BODY WEIGHT, WITH A MORE PRONOUNCED WEIGHT DIFFERENCE IN MALE ANIMALS (CLP VS. SHAM). MALE DESCENDANTS OF SEPSIS FATHERS, BUT NOT FEMALE DESCENDANTS, EXHIBITED LOWER PLASMA CONCENTRATIONS OF IL-6, TNF-ALPHA, AND IL-10 24 H AFTER INJECTION OF LPS. IN LINE, ONLY ALVEOLAR MACROPHAGES OF MALE DESCENDANTS OF SEPSIS FATHERS PRODUCED LESS TNF-ALPHA UPON ZYMOSAN STIMULATION COMPARED TO SHAM DESCENDANTS, WHILE LPS RESPONSES KEPT UNCHANGED. CONCLUSION: WE CAN PROVE THAT MALE-BUT SURPRISINGLY NOT FEMALE-DESCENDANTS OF POST-SEPSIS FATHERS SHOW A DAMPENED SYSTEMIC AS WELL AS PULMONARY IMMUNE RESPONSE. BASED ON THIS OBSERVATION OF AN IMMUNE HYPO-RESPONSIVITY, WE PROPOSE THAT MALE DESCENDANTS OF SEPSIS FATHERS ARE AT RISK TO DEVELOP FUNGAL AND BACTERIAL INFECTIONS AND MIGHT BENEFIT FROM THERAPEUTIC IMMUNE MODULATION. 2018 6 3455 41 HYPOMETHYLATION COORDINATES ANTAGONISTICALLY WITH HYPERMETHYLATION IN CANCER DEVELOPMENT: A CASE STUDY OF LEUKEMIA. BACKGROUND: METHYLATION CHANGES ARE FREQUENT IN CANCERS, BUT UNDERSTANDING HOW HYPER- AND HYPOMETHYLATED REGION CHANGES COORDINATE, ASSOCIATE WITH GENOMIC FEATURES, AND AFFECT GENE EXPRESSION IS NEEDED TO BETTER UNDERSTAND THEIR BIOLOGICAL SIGNIFICANCE. THE FUNCTIONAL SIGNIFICANCE OF HYPERMETHYLATION IS WELL STUDIED, BUT THAT OF HYPOMETHYLATION REMAINS LIMITED. HERE, WITH PAIRED EXPRESSION AND METHYLATION SAMPLES GATHERED FROM A PATIENT/CONTROL COHORT, WE ATTEMPT TO BETTER CHARACTERIZE THE GENE EXPRESSION AND METHYLATION CHANGES THAT TAKE PLACE IN CANCER FROM B CELL CHRONIC LYMPHOCYTE LEUKEMIA (B-CLL) SAMPLES. RESULTS: ACROSS THE DATASET, WE FOUND THAT CONSISTENT DIFFERENTIALLY HYPOMETHYLATED REGIONS (C-DMRS) ACROSS SAMPLES WERE RELATIVELY FEW COMPARED TO THE MANY POORLY CONSISTENT HYPO- AND HIGHLY CONSERVED HYPER-DMRS. HOWEVER, GENES IN THE HYPO-C-DMRS TENDED TO BE ASSOCIATED WITH FUNCTIONS ANTAGONISTIC TO THOSE IN THE HYPER-C-DMRS, LIKE DIFFERENTIATION, CELL-CYCLE REGULATION AND PROLIFERATION, SUGGESTING COORDINATED REGULATION OF METHYLATION CHANGES. HYPO-C-DMRS IN B-CLL WERE FOUND ENRICHED IN KEY SIGNALING PATHWAYS LIKE B CELL RECEPTOR AND P53 PATHWAYS AND GENES/MOTIFS ESSENTIAL FOR B LYMPHOPOIESIS. HYPO-C-DMRS TENDED TO BE PROXIMAL TO GENES WITH ELEVATED EXPRESSION IN CONTRAST TO THE TRANSCRIPTION SILENCING-MECHANISM IMPOSED BY HYPERMETHYLATION. HYPO-C-DMRS TENDED TO BE ENRICHED IN THE REGIONS OF ACTIVATING H4K4ME1/2/3, H3K79ME2, AND H3K27AC HISTONE MODIFICATIONS. IN COMPARISON, THE POLYCOMB REPRESSIVE COMPLEX 2 (PRC2) SIGNATURE, MARKED BY EZH2, SUZ12, CTCF BINDING-SITES, REPRESSIVE H3K27ME3 MARKS, AND "REPRESSED/POISED PROMOTER" STATES WERE ASSOCIATED WITH HYPER-C-DMRS. MOST HYPO-C-DMRS WERE FOUND IN INTRONS (36 %), 3' UNTRANSLATED REGIONS (29 %), AND INTERGENIC REGIONS (24 %). MANY OF THESE GENIC REGIONS ALSO OVERLAPPED WITH ENHANCERS. THE METHYLATION OF CPGS FROM 3'UTR EXONS WAS FOUND TO HAVE WEAK BUT POSITIVE CORRELATION WITH GENE EXPRESSION. IN CONTRAST, METHYLATION IN THE 5'UTR WAS NEGATIVELY CORRELATED WITH EXPRESSION. TO BETTER CHARACTERIZE THE OVERLAP BETWEEN METHYLATION AND EXPRESSION CHANGES, WE IDENTIFIED CORRELATION MODULES THAT ASSOCIATE WITH "APOPTOSIS" AND "LEUKOCYTE ACTIVATION". CONCLUSIONS: DESPITE CLINICAL HETEROGENEITY IN DISEASE PRESENTATION, A NUMBER OF METHYLATION CHANGES, BOTH HYPO AND HYPER, APPEAR TO BE COMMON IN B-CLL. HYPOMETHYLATION APPEARS TO PLAY AN ACTIVE, TARGETED, AND COMPLEMENTARY ROLE IN CANCER PROGRESSION, AND IT INTERPLAYS WITH HYPERMETHYLATION IN A COORDINATED FASHION IN THE CANCER PROCESS. 2016 7 2639 25 EPIGENOMIC ANALYSIS DETECTS WIDESPREAD GENE-BODY DNA HYPOMETHYLATION IN CHRONIC LYMPHOCYTIC LEUKEMIA. WE HAVE EXTENSIVELY CHARACTERIZED THE DNA METHYLOMES OF 139 PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) WITH MUTATED OR UNMUTATED IGHV AND OF SEVERAL MATURE B-CELL SUBPOPULATIONS THROUGH THE USE OF WHOLE-GENOME BISULFITE SEQUENCING AND HIGH-DENSITY MICROARRAYS. THE TWO MOLECULAR SUBTYPES OF CLL HAVE DIFFERING DNA METHYLOMES THAT SEEM TO REPRESENT EPIGENETIC IMPRINTS FROM DISTINCT NORMAL B-CELL SUBPOPULATIONS. DNA HYPOMETHYLATION IN THE GENE BODY, TARGETING MOSTLY ENHANCER SITES, WAS THE MOST FREQUENT DIFFERENCE BETWEEN NAIVE AND MEMORY B CELLS AND BETWEEN THE TWO MOLECULAR SUBTYPES OF CLL AND NORMAL B CELLS. ALTHOUGH DNA METHYLATION AND GENE EXPRESSION WERE POORLY CORRELATED, WE IDENTIFIED GENE-BODY CPG DINUCLEOTIDES WHOSE METHYLATION WAS POSITIVELY OR NEGATIVELY ASSOCIATED WITH EXPRESSION. WE HAVE ALSO RECOGNIZED A DNA METHYLATION SIGNATURE THAT DISTINGUISHES NEW CLINICO-BIOLOGICAL SUBTYPES OF CLL. WE PROPOSE AN EPIGENOMIC SCENARIO IN WHICH DIFFERENTIAL METHYLATION IN THE GENE BODY MAY HAVE FUNCTIONAL AND CLINICAL IMPLICATIONS IN LEUKEMOGENESIS. 2012 8 2904 33 GENE BODY METHYLATION FACILITATES THE TRANSCRIPTION OF CTSG VIA ANTISENSE LNCRNA AL136018.1 IN DERMATOMYOSITIC MYOIDEUM. DERMATOMYOSITIS (DM) IS CHARACTERIZED AS A CHRONIC AUTOIMMUNE DISORDER WITH MULTIPLE ORGAN INVOLVEMENT. OUR PREVIOUS STUDY HAS REVEALED THAT CATHEPSIN G (CTSG) HIGHLY EXPRESSED IN DERMATOMYOSITIC IN VIVO IS REGULATED BY DNMT3A THROUGH DNA METHYLATION OF 5'-C-PHOSPHATE-G-3' LOCI AT EXONS AND INTRONS. HOWEVER, THE MECHANISM OF GENE BODY METHYLATION ON REGULATING CTSG TRANSCRIPTION REMAINS UNKNOWN. IN THIS STUDY, WE STUDIED QUADRICEPS FEMORIS TISSUES OF SIX DM PATIENTS, AND OBSERVED THAT ANTISENSE LONG NONCODING RNA AL136018.1 CONTIGUOUS TO CTSG WAS HIGHLY EXPRESSED IN SKELETAL MUSCLE TISSUES OF DM AND POSITIVELY CORRELATED WITH THE TRANSCRIPTION LEVEL AND DNA METHYLATION LEVEL IN GENE BODY OF CTSG IN VIVO. MOREOVER, WE OBSERVED THAT THE LONGER TRANSCRIPT OF AL136018.1 (AL136018.1-201) COULD BIND TO THIRD AND FOURTH EXONS AND THIRD INTRON OF CTSG VIA THE 3'-END. FINALLY, AL136018.1-201 COULD RECRUIT DNMT3A TOWARDS GENE BODY VIA 5'-TERMINAL FOR ADDING DNA METHYLATION AND FACILITATING TRANSCRIPTION OF CTSG. TAKEN TOGETHER, OUR DATA UNCOVERED A NOVEL EPIGENETIC MECHANISM BEHIND THE GENE BODY METHYLATION FOR TRANSCRIPTIONAL REGULATION OF CTSG IN DM. 2021 9 1132 39 COMPREHENSIVE DNA METHYLATION ANALYSIS USING A METHYL-CPG-BINDING DOMAIN CAPTURE-BASED METHOD IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS. THE ROLE OF LONG NONCODING RNAS (LNCRNAS) IN CANCER IS COMING TO THE FOREFRONT DUE TO GROWING INTEREST IN UNDERSTANDING THEIR MECHANISTIC FUNCTIONS DURING CANCER DEVELOPMENT AND PROGRESSION. DESPITE THIS, THE GLOBAL EPIGENETIC REGULATION OF LNCRNAS AND REPETITIVE SEQUENCES IN CANCER HAS NOT BEEN WELL INVESTIGATED, PARTICULARLY IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). THIS STUDY FOCUSES ON A UNIQUE APPROACH: THE IMMUNOPRECIPITATION-BASED CAPTURE OF DOUBLE-STRANDED, METHYLATED DNA FRAGMENTS USING METHYL-BINDING DOMAIN (MBD) PROTEINS, FOLLOWED BY NEXT-GENERATION SEQUENCING (MBD-SEQ). CLL PATIENT SAMPLES BELONGING TO TWO PROGNOSTIC SUBGROUPS (5 IGVH MUTATED SAMPLES + 5 IGVH UNMUTATED SAMPLES) WERE USED IN THIS STUDY. ANALYSIS REVEALED 5,800 HYPERMETHYLATED AND 12,570 HYPOMETHYLATED CLL-SPECIFIC DIFFERENTIALLY METHYLATED GENES (CLLDMGS) COMPARED TO NORMAL HEALTHY CONTROLS. IMPORTANTLY, THESE RESULTS IDENTIFIED SEVERAL CLL-SPECIFIC, DIFFERENTIALLY METHYLATED LNCRNAS, REPETITIVE ELEMENTS, AND PROTEIN-CODING GENES WITH POTENTIAL PROGNOSTIC VALUE. THIS WORK OUTLINES A DETAILED PROTOCOL FOR AN MBD-SEQ AND BIOINFORMATICS PIPELINE DEVELOPED FOR THE COMPREHENSIVE ANALYSIS OF GLOBAL METHYLATION PROFILES IN HIGHLY CPG-RICH REGIONS USING CLL PATIENT SAMPLES. FINALLY, A PROTEIN-CODING GENE AND AN LNCRNA WERE VALIDATED USING PYROSEQUENCING, WHICH IS A HIGHLY QUANTITATIVE METHOD TO ANALYZE CPG METHYLATION LEVELS TO FURTHER CORROBORATE THE FINDINGS FROM THE MBD-SEQ PROTOCOL. 2017 10 1433 30 DIFFERENTIAL GENOME-WIDE ARRAY-BASED METHYLATION PROFILES IN PROGNOSTIC SUBSETS OF CHRONIC LYMPHOCYTIC LEUKEMIA. GLOBAL HYPOMETHYLATION AND REGIONAL HYPERMETHYLATION ARE WELL-KNOWN EPIGENETIC FEATURES OF CANCER; HOWEVER, IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), STUDIES ON GENOME-WIDE EPIGENETIC MODIFICATIONS ARE LIMITED. HERE, WE ANALYZED THE GLOBAL METHYLATION PROFILES IN CLL, BY APPLYING HIGH-RESOLUTION METHYLATION MICROARRAYS (27,578 CPG SITES) TO 23 CLL SAMPLES, BELONGING TO THE IMMUNOGLOBULIN HEAVY-CHAIN VARIABLE (IGHV) MUTATED (FAVORABLE) AND IGHV UNMUTATED/IGHV3-21 (POOR-PROGNOSTIC) SUBSETS. OVERALL, RESULTS DEMONSTRATED SIGNIFICANT DIFFERENCES IN METHYLATION PATTERNS BETWEEN THESE SUBGROUPS. SPECIFICALLY, IN IGHV UNMUTATED CLL, WE IDENTIFIED METHYLATION OF 7 KNOWN OR CANDIDATE TUMOR SUPPRESSOR GENES (EG, VHL, ABI3, AND IGSF4) AS WELL AS 8 UNMETHYLATED GENES INVOLVED IN CELL PROLIFERATION AND TUMOR PROGRESSION (EG, ADORA3 AND PRF1 ENHANCING THE NUCLEAR FACTOR-KAPPAB AND MITOGEN-ACTIVATED PROTEIN KINASE PATHWAYS, RESPECTIVELY). IN CONTRAST, THESE LATTER GENES WERE SILENCED BY METHYLATION IN IGHV MUTATED PATIENTS. THE ARRAY DATA WERE VALIDATED FOR SELECTED GENES USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION, QUANTITATIVE REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION, AND BISULFITE SEQUENCING. FINALLY, THE SIGNIFICANCE OF DNA METHYLATION IN REGULATING GENE PROMOTERS WAS SHOWN BY REINDUCING 4 METHYLATED TUMOR SUPPRESSOR GENES (EG, VHL AND ABI3) IN IGHV UNMUTATED SAMPLES USING THE METHYL-INHIBITOR 5-AZA-2'-DEOXYCYTIDINE. TAKEN TOGETHER, OUR DATA FOR THE FIRST TIME REVEAL DIFFERENCES IN GLOBAL METHYLATION PROFILES BETWEEN PROGNOSTIC SUBSETS OF CLL, WHICH MAY UNFOLD EPIGENETIC SILENCING MECHANISMS INVOLVED IN CLL PATHOGENESIS. 2010 11 1211 35 CPG ISLAND METHYLATION AND EXPRESSION OF THE SECRETED FRIZZLED-RELATED PROTEIN GENE FAMILY IN CHRONIC LYMPHOCYTIC LEUKEMIA. B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS INDICATING DISRUPTION OF APOPTOSIS. RESTRICTION LANDMARK GENOME SCANNING WAS DONE TO IDENTIFY NOVEL TARGET GENES SILENCED BY CPG ISLAND METHYLATION IN CLL. SECRETED FRIZZLED-RELATED PROTEIN 4 (SFRP4), A NEGATIVE REGULATOR OF THE WNT SIGNALING PATHWAY, WAS FOUND TO BE FREQUENTLY METHYLATED IN CLL SAMPLES. WNT SIGNALING HAS BEEN SHOWN TO CONTROL NORMAL APOPTOTIC BEHAVIOR AND IS REQUIRED FOR NORMAL B-CELL DEVELOPMENT WHEREAS ABERRANT ACTIVATION OF THIS PATHWAY HAS BEEN OBSERVED IN CLL. WE SHOW ABERRANT DNA METHYLATION AND SILENCING OF SFRP4, AS WELL AS OF ADDITIONAL SFRP FAMILY MEMBERS, IN PRIMARY CLL SAMPLES. INDUCTION OF THEIR EXPRESSION IN A DOSE-DEPENDENT MANNER FOLLOWING TREATMENT WITH A DEMETHYLATING AGENT, 5-AZA-2'-DEOXYCYTIDINE, WAS SHOWN. OF THE FIVE SFRP FAMILY MEMBERS STUDIED IN DETAIL, SFRP1 WAS HYPERMETHYLATED AND DOWN-REGULATED IN ALL CLL PATIENT SAMPLES STUDIED, SUGGESTING THAT THIS EPIGENETIC EVENT IS A CRITICAL STEP DURING LEUKEMOGENESIS. OUR RESULTS SUGGEST THAT SILENCING OF SFRPS BY CPG ISLAND METHYLATION IS ONE POSSIBLE MECHANISM CONTRIBUTING TO ABERRANT ACTIVATION OF WNT SIGNALING PATHWAY IN CLL. 2006 12 3138 39 GLOBAL DNA METHYLATION PROFILING REVEALS NEW INSIGHTS INTO EPIGENETICALLY DEREGULATED PROTEIN CODING AND LONG NONCODING RNAS IN CLL. BACKGROUND: METHYL-CPG-BINDING DOMAIN PROTEIN ENRICHED GENOME-WIDE SEQUENCING (MBD-SEQ) IS A ROBUST AND POWERFUL METHOD FOR ANALYZING METHYLATED CPG-RICH REGIONS WITH COMPLETE GENOME-WIDE COVERAGE. IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), THE ROLE OF CPG METHYLATED REGIONS ASSOCIATED WITH TRANSCRIBED LONG NONCODING RNAS (LNCRNA) AND REPETITIVE GENOMIC ELEMENTS ARE POORLY UNDERSTOOD. BASED ON MBD-SEQ, WE CHARACTERIZED THE GLOBAL METHYLATION PROFILE OF HIGH CPG-RICH REGIONS IN DIFFERENT CLL PROGNOSTIC SUBGROUPS BASED ON IGHV MUTATIONAL STATUS. RESULTS: OUR STUDY IDENTIFIED 5800 HYPERMETHYLATED AND 12,570 HYPOMETHYLATED CLL-SPECIFIC DIFFERENTIALLY METHYLATED GENES (CLLDMGS) COMPARED TO NORMAL CONTROLS. FROM CLLDMGS, 40 % OF HYPERMETHYLATED AND 60 % OF HYPOMETHYLATED GENES WERE MAPPED TO NONCODING RNAS. IN ADDITION, WE FOUND THAT THE MAJOR REPETITIVE ELEMENTS SUCH AS SHORT INTERSPERSED ELEMENTS (SINE) AND LONG INTERSPERSED ELEMENTS (LINE) HAVE A HIGH PERCENTAGE OF CLLDMRS (DIFFERENTIALLY METHYLATED REGIONS) IN IGHV SUBGROUPS COMPARED TO NORMAL CONTROLS. FINALLY, TWO NOVEL LNCRNAS (HYPERMETHYLATED CRNDE AND HYPOMETHYLATED AC012065.7) WERE VALIDATED IN AN INDEPENDENT CLL SAMPLE COHORT (48 SAMPLES) COMPARED WITH 6 NORMAL SORTED B CELL SAMPLES USING QUANTITATIVE PYROSEQUENCING ANALYSIS. THE METHYLATION LEVELS SHOWED AN INVERSE CORRELATION TO GENE EXPRESSION LEVELS ANALYZED BY REAL-TIME QUANTITATIVE PCR. NOTABLY, SURVIVAL ANALYSIS REVEALED THAT HYPERMETHYLATION OF CRNDE AND HYPOMETHYLATION OF AC012065.7 CORRELATED WITH AN INFERIOR OUTCOME. CONCLUSIONS: THUS, OUR COMPREHENSIVE METHYLATION ANALYSIS BY MBD-SEQ PROVIDED NOVEL HYPER AND HYPOMETHYLATED LONG NONCODING RNAS, REPETITIVE ELEMENTS, ALONG WITH PROTEIN CODING GENES AS POTENTIAL EPIGENETIC-BASED CLL-SIGNATURE GENES INVOLVED IN DISEASE PATHOGENESIS AND PROGNOSIS. 2016 13 129 66 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 14 6307 30 THE REFERENCE EPIGENOME AND REGULATORY CHROMATIN LANDSCAPE OF CHRONIC LYMPHOCYTIC LEUKEMIA. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS A FREQUENT HEMATOLOGICAL NEOPLASM IN WHICH UNDERLYING EPIGENETIC ALTERATIONS ARE ONLY PARTIALLY UNDERSTOOD. HERE, WE ANALYZE THE REFERENCE EPIGENOME OF SEVEN PRIMARY CLLS AND THE REGULATORY CHROMATIN LANDSCAPE OF 107 PRIMARY CASES IN THE CONTEXT OF NORMAL B CELL DIFFERENTIATION. WE IDENTIFY THAT THE CLL CHROMATIN LANDSCAPE IS LARGELY INFLUENCED BY DISTINCT DYNAMICS DURING NORMAL B CELL MATURATION. BEYOND THIS, WE DEFINE EXTENSIVE CATALOGUES OF REGULATORY ELEMENTS DE NOVO REPROGRAMMED IN CLL AS A WHOLE AND IN ITS MAJOR CLINICO-BIOLOGICAL SUBTYPES CLASSIFIED BY IGHV SOMATIC HYPERMUTATION LEVELS. WE UNCOVER THAT IGHV-UNMUTATED CLLS HARBOR MORE ACTIVE AND OPEN CHROMATIN THAN IGHV-MUTATED CASES. FURTHERMORE, WE SHOW THAT DE NOVO ACTIVE REGIONS IN CLL ARE ENRICHED FOR NFAT, FOX AND TCF/LEF TRANSCRIPTION FACTOR FAMILY BINDING SITES. ALTHOUGH MOST GENETIC ALTERATIONS ARE NOT ASSOCIATED WITH CONSISTENT EPIGENETIC PROFILES, CLLS WITH MYD88 MUTATIONS AND TRISOMY 12 SHOW DISTINCT CHROMATIN CONFIGURATIONS. FURTHERMORE, WE OBSERVE THAT NON-CODING MUTATIONS IN IGHV-MUTATED CLLS ARE ENRICHED IN H3K27AC-ASSOCIATED REGULATORY ELEMENTS OUTSIDE ACCESSIBLE CHROMATIN. OVERALL, THIS STUDY PROVIDES AN INTEGRATIVE PORTRAIT OF THE CLL EPIGENOME, IDENTIFIES EXTENSIVE NETWORKS OF ALTERED REGULATORY ELEMENTS AND SHEDS LIGHT ON THE RELATIONSHIP BETWEEN THE GENETIC AND EPIGENETIC ARCHITECTURE OF THE DISEASE. 2018 15 698 56 BROMODOMAIN CONTAINING PROTEIN 4 (BRD4) REGULATES EXPRESSION OF ITS INTERACTING COACTIVATORS IN THE INNATE RESPONSE TO RESPIRATORY SYNCYTIAL VIRUS. BROMODOMAIN-CONTAINING PROTEIN 4 PLAYS A CENTRAL ROLE IN COORDINATING THE COMPLEX EPIGENETIC COMPONENT OF THE INNATE IMMUNE RESPONSE. PREVIOUS STUDIES IMPLICATED BRD4 AS A COMPONENT OF A CHROMATIN-MODIFYING COMPLEX THAT IS DYNAMICALLY RECRUITED TO A NETWORK OF PROTECTIVE CYTOKINES BY BINDING ACTIVATED TRANSCRIPTION FACTORS, POLYMERASES, AND HISTONES TO TRIGGER THEIR RAPID EXPRESSION VIA TRANSCRIPTIONAL ELONGATION. OUR PREVIOUS STUDY EXTENDED OUR UNDERSTANDING OF THE AIRWAY EPITHELIAL BRD4 INTERACTOME BY IDENTIFYING OVER 100 FUNCTIONALLY IMPORTANT COACTIVATORS AND TRANSCRIPTION FACTORS, WHOSE ASSOCIATION IS INDUCED BY RESPIRATORY SYNCYTIAL VIRUS (RSV) INFECTION. RSV IS AN ETIOLOGICAL AGENT OF RECURRENT RESPIRATORY TRACT INFECTIONS ASSOCIATED WITH EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. USING A HIGHLY SELECTIVE SMALL-MOLECULE BRD4 INHIBITOR (ZL0454) DEVELOPED BY US, WE EXTEND THESE FINDINGS TO IDENTIFY THE GENE REGULATORY NETWORK DEPENDENT ON BRD4 BROMODOMAIN (BD) INTERACTIONS. HUMAN SMALL AIRWAY EPITHELIAL CELLS WERE INFECTED IN THE ABSENCE OR PRESENCE OF ZL0454, AND GENE EXPRESSION PROFILING WAS PERFORMED. A HIGHLY REPRODUCIBLE DATASET WAS OBTAINED WHICH INDICATED THAT BRD4 MEDIATES BOTH ACTIVATION AND REPRESSION OF RSV-INDUCIBLE GENE REGULATORY NETWORKS CONTROLLING CYTOKINE EXPRESSION, INTERFERON (IFN) PRODUCTION, AND EXTRACELLULAR MATRIX REMODELING. INDEX GENES OF FUNCTIONALLY SIGNIFICANT CLUSTERS WERE VALIDATED INDEPENDENTLY. WE DISCOVER THAT BRD4 REGULATES THE EXPRESSION OF ITS OWN GENE DURING THE INNATE IMMUNE RESPONSE. INTERESTINGLY, BRD4 ACTIVATES THE EXPRESSION OF NFKAPPAB/RELA, A COACTIVATOR THAT BINDS TO BRD4 IN A BD-DEPENDENT MANNER. WE EXTEND THIS FINDING TO SHOW THAT BRD4 ALSO REGULATES OTHER COMPONENTS OF ITS FUNCTIONAL INTERACTOME, INCLUDING THE MEDIATOR (MED) COACTIVATOR COMPLEX AND THE SWI/SNF-RELATED, MATRIX-ASSOCIATED, ACTIN-DEPENDENT REGULATOR OF CHROMATIN (SMARC) SUBUNITS. TO PROVIDE FURTHER INSIGHT INTO MECHANISMS FOR BRD4 IN RSV EXPRESSION, WE MAPPED 7,845 RSV-INDUCIBLE TN5 TRANSPOSASE PEAKS ONTO THE BRD4-DEPENDENT GENE BODIES. THESE WERE LOCATED IN PROMOTERS AND INTRONS OF CYTOSTRUCTURAL AND EXTRACELLULAR MATRIX (ECM) FORMATION GENES. THESE DATA INDICATE THAT BRD4 MEDIATES THE DYNAMIC RESPONSE OF AIRWAY EPITHELIAL CELLS TO RNA INFECTION BY MODULATING THE EXPRESSION OF ITS COACTIVATORS, CONTROLLING THE EXPRESSION OF HOST DEFENSE MECHANISMS AND REMODELING GENES THROUGH CHANGES IN PROMOTER ACCESSIBILITY. 2021 16 5243 24 PROGNOSTIC IMPACT OF EPIGENETIC CLASSIFICATION IN CHRONIC LYMPHOCYTIC LEUKEMIA: THE CASE OF SUBSET #2. BASED ON THE METHYLATION STATUS OF 5 SINGLE CPG SITES, A NOVEL EPIGENETIC CLASSIFICATION OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) WAS RECENTLY PROPOSED, CLASSIFYING CLL PATIENTS INTO 3 CLINICO-BIOLOGICAL SUBGROUPS WITH DIFFERENT OUTCOME, TERMED MEMORY LIKE CLL (M-CLL), NAIVE LIKE CLL (N-CLL), AND A THIRD INTERMEDIATE CLL SUBGROUP (I-CLL). WHILE M-CLL AND N-CLL PATIENTS AT LARGE CORRESPONDED TO PATIENTS CARRYING MUTATED AND UNMUTATED IGHV GENES, RESPECTIVELY, LIMITED INFORMATION EXISTS REGARDING THE LESS DEFINED I-CLL GROUP. USING PYROSEQUENCING, WE INVESTIGATED THE PROGNOSTIC IMPACT OF THE PROPOSED 5 CPG SIGNATURE IN A WELL-CHARACTERIZED CLL COHORT (135 CASES), INCLUDING IGHV-MUTATED AND UNMUTATED PATIENTS AS WELL AS CLINICALLY AGGRESSIVE STEREOTYPED SUBSET #2 PATIENTS. OVERALL, WE CONFIRMED THE SIGNATURE'S ASSOCIATION WITH ESTABLISHED PROGNOSTIC MARKERS. MOREOVER, IN THE PRESENCE OF THE IGHV MUTATIONAL STATUS, THE EPIGENETIC SIGNATURE REMAINED INDEPENDENTLY ASSOCIATED WITH BOTH TIME-TO-FIRST-TREATMENT AND OVERALL SURVIVAL IN MULTIVARIATE ANALYSES. AS A PRIME FINDING, WE OBSERVED THAT SUBSET #2 PATIENTS WERE PREDOMINANTLY CLASSIFIED AS I-CLL, PROBABLY REFLECTING THEIR BORDERLINE IGHV MUTATIONAL STATUS (97-99% GERMLINE IDENTITY), THOUGH HAVING A SIMILARLY POOR PROGNOSIS AS N-CLL PATIENTS. IN SUMMARY, WE VALIDATED THE EPIGENETIC CLASSIFIER AS AN INDEPENDENT FACTOR IN CLL PROGNOSTICATION AND PROVIDE FURTHER EVIDENCE THAT SUBSET #2 IS A MEMBER OF THE I-CLL GROUP, HENCE SUPPORTING THE EXISTENCE OF A THIRD, INTERMEDIATE EPIGENETIC SUBGROUP. 2016 17 3444 31 HYPERMETHYLATION OF E-CADHERIN IN LEUKEMIA. E-CADHERIN GENE IS OFTEN TERMED A "METASTASIS SUPPRESSOR" GENE BECAUSE THE E-CADHERIN PROTEIN CAN SUPPRESS TUMOR CELL INVASION AND METASTASIS. INACTIVATION OF THE E-CADHERIN GENE OCCURS IN UNDIFFERENTIATED SOLID TUMORS BY BOTH GENETIC AND EPIGENETIC MECHANISMS; HOWEVER, THE ROLE OF E-CADHERIN IN HEMATOLOGIC MALIGNANCIES IS ONLY NOW BEING RECOGNIZED. E-CADHERIN EXPRESSION IS ESSENTIAL FOR ERYTHROBLAST AND NORMOBLAST MATURATION, YET EXPRESSION IS REDUCED OR ABSENT IN LEUKEMIC BLAST CELLS. THIS STUDY EXAMINED THE MESSENGER RNA (MRNA) AND PROTEIN EXPRESSION OF THE E-CADHERIN GENE IN BONE MARROW AND BLOOD SAMPLES FROM NORMAL DONORS AND PATIENTS WITH LEUKEMIA. WE FOUND THAT ALL NORMAL DONOR SAMPLES EXPRESSED E-CADHERIN MRNA, WHEREAS BOTH SAMPLES OF ACUTE MYELOGENOUS LEUKEMIA AND CHRONIC LYMPHOCYTIC LEUKEMIA HAD A SIGNIFICANT REDUCTION OR ABSENCE OF EXPRESSION. HOWEVER, NORMAL BLAST COUNTERPARTS EXPRESSED ONLY A LOW LEVEL OF E-CADHERIN SURFACE PROTEIN. SODIUM BISULPHITE GENOMIC SEQUENCING WAS USED TO FULLY CHARACTERIZE THE METHYLATION PATTERNS OF THE CPG ISLAND ASSOCIATED WITH THE E-CADHERIN GENE PROMOTER IN THOSE SAMPLES WITH MATCHED DNA. ALL OF THE NORMAL CONTROL SAMPLES WERE ESSENTIALLY UNMETHYLATED; HOWEVER, 14 OF 18 (78%) OF THE LEUKEMIA SAMPLES HAD ABNORMAL HYPERMETHYLATION OF THE E-CADHERIN CPG ISLAND. IN FACT BOTH ALLELES OF THE E-CADHERIN GENE WERE OFTEN HYPERMETHYLATED. WE CONCLUDE THE E-CADHERIN GENE IS A COMMON TARGET FOR HYPERMETHYLATION IN HEMATOLOGIC MALIGNANCIES. 2000 18 1581 25 DNA METHYLATION PROFILES IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS TREATED WITH CHEMOIMMUNOTHERAPY. BACKGROUND: IN ORDER TO GAIN INSIGHT INTO THE CONTRIBUTION OF DNA METHYLATION TO DISEASE PROGRESSION OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), USING 450K ILLUMINA ARRAYS, WE DETERMINED THE DNA METHYLATION PROFILES IN PAIRED PRE-TREATMENT/RELAPSE SAMPLES FROM 34 CLL PATIENTS TREATED WITH CHEMOIMMUNOTHERAPY, MOSTLY (N = 31) WITH THE FLUDARABINE-CYCLOPHOSPHAMIDE-RITUXIMAB (FCR) REGIMEN. RESULTS: THE EXTENT OF IDENTIFIED CHANGES IN CLL CELLS VERSUS MEMORY B CELLS FROM HEALTHY DONORS WAS TERMED "EPIGENETIC BURDEN" (EB) WHEREAS THE NUMBER OF CHANGES BETWEEN THE PRE-TREATMENT VERSUS THE RELAPSE SAMPLE WAS TERMED "RELAPSE CHANGES" (RC). SIGNIFICANT (P < 0.05) ASSOCIATIONS WERE IDENTIFIED BETWEEN (I) HIGH EB AND SHORT TIME-TO-FIRST-TREATMENT (TTFT); AND, (II) FEW RCS AND SHORT TIME-TO-RELAPSE. BOTH THE EB AND THE RC CLUSTERED IN SPECIFIC GENOMIC REGIONS AND CHROMATIN STATES, INCLUDING REGULATORY REGIONS CONTAINING BINDING SITES OF TRANSCRIPTION FACTORS IMPLICATED IN B CELL AND CLL BIOLOGY. CONCLUSIONS: OVERALL, WE SHOW THAT DNA METHYLATION IN CLL FOLLOWS DIFFERENT DYNAMICS IN RESPONSE TO CHEMOIMMUNOTHERAPY. THESE EPIGENETIC ALTERATIONS WERE LINKED WITH SPECIFIC CLINICAL AND BIOLOGICAL FEATURES. 2019 19 2438 31 EPIGENETIC SILENCING OF THE CIRCADIAN CLOCK GENE CRY1 IS ASSOCIATED WITH AN INDOLENT CLINICAL COURSE IN CHRONIC LYMPHOCYTIC LEUKEMIA. DISRUPTION OF CIRCADIAN RHYTHM IS BELIEVED TO PLAY A CRITICAL ROLE IN CANCER DEVELOPMENT. CRYPTOCHROME 1 (CRY1) IS A CORE COMPONENT OF THE MAMMALIAN CIRCADIAN CLOCK AND WE HAVE PREVIOUSLY SHOWN ITS DEREGULATED EXPRESSION IN A SUBGROUP OF PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). USING REAL-TIME RT-PCR IN A COHORT OF 76 CLL PATIENTS AND 35 NORMAL BLOOD DONORS WE NOW DEMONSTRATE THAT DIFFERENTIAL CRY1 MRNA EXPRESSION IN HIGH-RISK (HR) CD38+/IMMUNOGLOBULIN VARIABLE HEAVY CHAIN GENE (IGVH) UNMUTATED PATIENTS AS COMPARED TO LOW-RISK (LR) CD38-/IGVH MUTATED PATIENTS CAN BE ATTRIBUTED TO DOWN-MODULATION OF CRY1 IN LR CLL CASES. ANALYSIS OF THE DNA METHYLATION PROFILE OF THE CRY1 PROMOTER IN A SUBGROUP OF 57 PATIENTS REVEALED THAT CRY1 EXPRESSION IN LR CLL CELLS IS SILENCED BY ABERRANT PROMOTER CPG ISLAND HYPERMETHYLATION. THE METHYLATION PATTERN OF THE CRY1 PROMOTER PROVED TO HAVE HIGH PROGNOSTIC IMPACT IN CLL WHERE ABERRANT PROMOTER METHYLATION PREDICTED A FAVOURABLE OUTCOME. CRY1 MRNA TRANSCRIPT LEVELS DID NOT CHANGE OVER TIME IN THE MAJORITY OF PATIENTS WHERE SEQUENTIAL SAMPLES WERE AVAILABLE FOR ANALYSIS. WE ALSO COMPARED THE CRY1 EXPRESSION IN CLL WITH OTHER LYMPHOID MALIGNANCIES AND OBSERVED EPIGENETIC SILENCING OF CRY1 IN A PATIENT WITH B CELL ACUTE LYMPHOBLASTIC LEUKEMIA (B-ALL). 2012 20 3475 35 IDENTIFICATION OF A STAT5 TARGET GENE, DPF3, PROVIDES NOVEL INSIGHTS IN CHRONIC LYMPHOCYTIC LEUKEMIA. STAT5 CONTROLS ESSENTIAL CELLULAR FUNCTIONS AND IS ENCODED BY TWO GENES, STAT5A AND STAT5B. TO PROVIDE INSIGHT TO THE MECHANISMS LINKING HEMATOLOGIC MALIGNANCY TO STAT5 ACTIVATION/REGULATION OF TARGET GENES, WE IDENTIFIED STAT5 TARGET GENES AND FOCUSED ON DPF3 GENE, WHICH ENCODES FOR AN EPIGENETIC FACTOR. DPF3 EXPRESSION WAS INDUCED UPON IL-3 STIMULATION IN BA/F3 CELLS, WHILE STRONG BINDING OF BOTH STAT5A AND STAT5B WAS DETECTED IN ITS PROMOTER. REDUCED EXPRESSION OF DPF3 WAS DETECTED IN BA/F3 CELLS WITH STAT5A AND STAT5B KNOCK-DOWN, SUGGESTING THAT THIS GENE IS POSITIVELY REGULATED BY STAT5, UPON IL-3 STIMULATION. FURTHERMORE, THIS GENE WAS SIGNIFICANTLY UP-REGULATED IN CLL PATIENTS, WHERE DPF3 GENE/PROTEIN UP-REGULATION AND STRONG STAT5 BINDING TO THE DPF3 PROMOTER, CORRELATED WITH INCREASED STAT5 ACTIVATION, MAINLY IN NON-MALIGNANT MYELOID CELLS (GRANULOCYTES). OUR FINDINGS PROVIDE INSIGHTS IN THE STAT5 DEPENDENT TRANSCRIPTIONAL REGULATION OF DPF3, AND DEMONSTRATE FOR THE FIRST TIME INCREASED STAT5 ACTIVATION IN GRANULOCYTES OF CLL PATIENTS. NOVEL ROUTES OF INVESTIGATION ARE OPENED TO FACILITATE THE UNDERSTANDING OF THE ROLE OF STAT5 ACTIVATION IN THE COMMUNICATION BETWEEN NON-MALIGNANT MYELOID AND MALIGNANT B-CELLS, AND THE FUNCTIONS OF STAT5 TARGET GENES NETWORKS IN CLL BIOLOGY. 2013