1 2593 110 EPIGENETICS OF RIBOSOMAL RNA GENES. THIS REVIEW IS FOCUSED ON BIOLOGY OF GENES ENCODING RIBOSOMAL RNA (RRNA) IN MAMMALS. RRNA IS A STRUCTURAL COMPONENT OF THE MOST ABUNDANT CELLULAR MOLECULE, THE RIBOSOME. THERE ARE MANY COPIES OF RRNA GENES PER GENOME THAT ARE UNDER TIGHT TRANSCRIPTIONAL CONTROL BY EPIGENETIC MECHANISMS SERVING TO MEET CELLULAR NEEDS IN PROTEIN SYNTHESIS. CURIOUSLY, ONLY A FRACTION OF RRNA GENES IS USED EVEN IN THE FAST-GROWING CELLS, RAISING A QUESTION WHY UNUSED COPIES OF THESE GENES HAVE NOT BEEN LOST DURING EVOLUTION. TWO PLAUSIBLE EXPLANATIONS ARE DISCUSSED. FIRST, THERE IS EVIDENCE THAT BESIDES THEIR DIRECT FUNCTION IN PRODUCTION OF RRNA, RIBOSOMAL RNA GENES ARE INVOLVED IN REGULATION OF MANY OTHER GENES IN THE NUCLEUS BY FORMING EITHER TEMPORARY OR PERSISTENT COMPLEXES WITH THESE GENES. SECOND, IT SEEMS THAT RRNA GENES ALSO PLAY A ROLE IN THE MAINTENANCE OF GENOME STABILITY, WHERE LOWER COPY NUMBER OF RRNA GENES DESTABILIZES THE GENOME. THESE "ADDITIONAL" FUNCTIONS OF RRNA GENES MAKE THEM RECURRENT CANDIDATE DRIVERS OF CHRONIC HUMAN DISEASES AND AGING. EXPERIMENTAL SUPPORT FOR THE INVOLVEMENT OF THESE GENES IN HUMAN DISEASES AND POTENTIAL MECHANISMS ARE ALSO DISCUSSED. 2022 2 355 18 ALTERED MITOCHONDRIAL DNA METHYLATION AND MITOCHONDRIAL DNA COPY NUMBER IN AN APP/PS1 TRANSGENIC MOUSE MODEL OF ALZHEIMER DISEASE. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISEASE AND MITOCHONDRIAL IMPAIRMENT IS A KEY FEATURE OF AD. THE MITOCHONDRIAL DNA (MTDNA) EPIGENETIC MECHANISM IS A RELATIVELY NEW FIELD COMPARED TO NUCLEAR DNA. THE RELATIONSHIP BETWEEN MTDNA EPIGENETIC MECHANISM AND AD HASN'T BEEN ESTABLISHED. SO WE ANALYZED THE MTDNA METHYLATION IN D-LOOP REGION AND 12 S RRNA GENE IN THE HIPPOCAMPI IN AMYLOID PRECURSOR PROTEIN/PRESENILIN 1 (APP/PS1) TRANSGENIC MICE BY BISULFITE PYROSEQUENCING. MITOCHONDRIAL DNA COPY NUMBER AND GENE EXPRESSION WERE STUDIED BY QUANTITATIVE REAL-TIME PCR (QRT-PCR). WE OBSERVED A DECREASE IN THE DISPLACEMENT LOOP (D-LOOP) METHYLATION AND AN INCREASE IN 12 S RRNA GENE METHYLATION, WHILE BOTH THE MTDNA COPY NUMBER AND THE MITOCHONDRIAL GENE EXPRESSION WERE REDUCED IN APP/PS1 TRANSGENIC MICE. IN SUMMARY, THE PRESENT FINDING SUGGEST THAT MTDNA METHYLATION MAY PLAY A ROLE IN AD PATHOLOGY, WHICH WARRANTS LARGER FUTURE INVESTIGATIONS. 2019 3 5061 29 PHF6 FUNCTIONS AS A TUMOR SUPPRESSOR BY RECRUITING METHYLTRANSFERASE SUV39H1 TO NUCLEOLAR REGION AND OFFERS A NOVEL THERAPEUTIC TARGET FOR PHF6-MUNTANT LEUKEMIA. MUTATIONS IN THE PLANT HOMEODOMAIN-LIKE FINGER PROTEIN 6 (PHF6) GENE ARE STRONGLY ASSOCIATED WITH ACUTE MYELOID (AML) AND T-CELL ACUTE LYMPHOBLASTIC LEUKEMIA (T-ALL). IN THIS STUDY, WE DEMONSTRATED THAT PHF6 CAN BIND TO H3K9ME3 AND H3K27ME1 ON THE NUCLEOLAR CHROMATIN AND RECRUIT HISTONE METHYLTRANSFERASE SUV39H1 TO THE RDNA LOCUS. THE DELETION OF PHF6 CAUSED A DECREASE IN THE RECRUITMENT OF SUV39H1 TO RDNA GENE LOCI, RESULTING IN A REDUCTION IN THE LEVEL OF H3K9ME3 AND THE PROMOTION OF RDNA TRANSCRIPTION. THE KNOCKDOWN OF EITHER SUV39H1 OR PHF6 SIGNIFICANTLY ATTENUATED THE EFFECTS OF INCREASE IN H3K9ME3 AND SUPPRESSED THE TRANSCRIPTION OF RDNA INDUCED BY THE OVEREXPRESSION OF THE OTHER INTERACTING PARTNER, THEREBY ESTABLISHING AN INTERDEPENDENT RELATIONSHIP BETWEEN PHF6 AND SUV39H1 IN THEIR CONTROL OF RRNA TRANSCRIPTION. THE PHF6 CLINICAL MUTANTS SIGNIFICANTLY IMPAIRED THE ABILITY TO BIND AND RECRUIT SUV39H1 TO THE RDNA LOCI, RESULTING IN AN INCREASE IN RDNA TRANSCRIPTION ACTIVITY, THE PROLIFERATION OF IN VITRO LEUKEMIA CELLS, AND THE GROWTH OF IN VIVO MOUSE XENOGRAFTS. IMPORTANTLY, SIGNIFICANTLY ELEVATED LEVELS OF PRE-RRNA WERE OBSERVED IN CLINICAL AML PATIENTS WHO POSSESSED A MUTATED VERSION OF PHF6. THE SPECIFIC RDNA TRANSCRIPTION INHIBITOR CX5461 SIGNIFICANTLY REDUCED THE RESISTANCE OF U937 AML CELLS DEFICIENT IN PHF6 TO CYTARABINE, THE DRUG THAT IS MOST COMMONLY USED TO TREAT AML. COLLECTIVELY, WE REVEALED A NOVEL MOLECULAR MECHANISM BY WHICH PHF6 RECRUITS METHYLTRANSFERASE SUV39H1 TO THE NUCLEOLAR REGION IN LEUKEMIA AND PROVIDED A POTENTIAL THERAPEUTIC TARGET FOR PHF6-MUTANT LEUKEMIA. 2022 4 1346 31 DETECTION OF TRANSGENERATIONAL SPERMATOGENIC INHERITANCE OF ADULT MALE ACQUIRED CNS GENE EXPRESSION CHARACTERISTICS USING A DROSOPHILA SYSTEMS MODEL. AVAILABLE INSTANCES OF INHERITANCE OF EPIGENETIC TRANSGENERATIONAL PHENOTYPE ARE LIMITED TO ENVIRONMENTAL EXPOSURES DURING EMBRYONIC AND ADULT GONADAL DEVELOPMENT. ADULT EXPOSURES CAN ALSO AFFECT GAMETOGENESIS AND THEREBY POTENTIALLY RESULT IN REPROGRAMMING OF THE GERMLINE. ALTHOUGH EXAMPLES OF EPIGENETIC EFFECTS ON GAMETOGENESIS EXIST, IT IS NOTABLE THAT TRANSGENERATIONAL INHERITANCE OF ENVIRONMENT-INDUCED ADULT PHENOTYPE HAS NOT YET BEEN REPORTED. EPIGENETIC CODES ARE CONSIDERED TO BE CRITICAL IN NEURAL PLASTICITY. A DROSOPHILA SYSTEMS MODEL OF PENTYLENETETRAZOLE (PTZ) INDUCED LONG-TERM BRAIN PLASTICITY HAS RECENTLY BEEN DESCRIBED. IN THIS MODEL, CHRONIC PTZ TREATMENT OF ADULT MALES CAUSES ALTERATIONS IN CNS TRANSCRIPTOME. HERE, WE DESCRIBE OUR SEARCH FOR TRANSGENERATIONAL SPERMATOGENIC INHERITANCE OF PTZ INDUCED GENE EXPRESSION PHENOTYPE ACQUIRED BY ADULT DROSOPHILA MALES. WE GENERATED CNS TRANSCRIPTOMIC PROFILES OF F(1) ADULTS AFTER TREATING F(0) ADULT MALES WITH PTZ AND OF F(2) ADULTS RESULTING FROM A CROSS BETWEEN F(1) MALES AND NORMAL FEMALES. SURPRISINGLY, MICROARRAY CLUSTERING SHOWED F(1) MALE PROFILE AS CLOSEST TO F(1) FEMALE AND F(0) MALE PROFILE CLOSEST TO F(2) MALE. DIFFERENTIALLY EXPRESSED GENES IN F(1) MALES, F(1) FEMALES AND F(2) MALES SHOWED SIGNIFICANT OVERLAP WITH THOSE CAUSED BY PTZ. INTERESTINGLY, MICROARRAY EVIDENCE ALSO LED TO THE IDENTIFICATION OF UPREGULATED RRNA IN F(2) MALES. NEXT, WE GENERATED MICROARRAY EXPRESSION PROFILES OF ADULT TESTIS FROM F(0) AND F(1) MALES. FURTHER SURPRISING, CLUSTERING OF CNS AND TESTIS PROFILES AND MATCHING OF DIFFERENTIALLY EXPRESSED GENES IN THEM PROVIDED EVIDENCE OF A SPERMATOGENIC MECHANISM IN THE TRANSGENERATIONAL EFFECT OBSERVED. TO OUR KNOWLEDGE, WE REPORT FOR THE FIRST TIME DETECTION OF TRANSGENERATIONAL SPERMATOGENIC INHERITANCE OF ADULT ACQUIRED SOMATIC GENE EXPRESSION CHARACTERISTIC. THE DROSOPHILA SYSTEMS MODEL OFFERS AN EXCELLENT OPPORTUNITY TO UNDERSTAND THE EPIGENETIC MECHANISMS UNDERLYING THE PHENOMENON. THE FINDING THAT ADULT ACQUIRED TRANSCRIPTOMIC ALTERATION IN SOMA IS SPERMATOGENICALLY INHERITED ACROSS GENERATIONS HAS POTENTIAL IMPLICATIONS IN HUMAN HEALTH AND EVOLUTION. 2009 5 6383 28 THE ROLE OF PHF6 IN HEMATOPOIESIS AND HEMATOLOGIC MALIGNANCIES. EPIGENETIC REGULATION OF GENE EXPRESSION REPRESENTS AN IMPORTANT MECHANISM IN THE MAINTENANCE OF STEM CELL FUNCTION. ALTERATIONS IN EPIGENETIC REGULATION CONTRIBUTE TO THE PATHOGENESIS OF HEMATOLOGICAL MALIGNANCIES. PLANT HOMEODOMAIN FINGER PROTEIN 6 (PHF6) IS A MEMBER OF THE PLANT HOMEODOMAIN (PHD)-LIKE ZINC FINGER FAMILY OF PROTEINS THAT IS INVOLVED IN TRANSCRIPTIONAL REGULATION THROUGH THE MODIFICATION OF THE CHROMATIN STATE. GERMLINE MUTATION OF PHF6 IS THE CAUSATIVE GENETIC ALTERATION OF THE X-LINKED MENTAL RETARDATION BORJESON-FORSSMAN-LEHMANN SYNDROME (BFLS). SOMATIC MUTATIONS IN PHF6 ARE IDENTIFIED IN HUMAN LEUKEMIA, SUCH AS ADULT T-CELL ACUTE LYMPHOBLASTIC LEUKEMIA (T-ALL, ~ 38%), PEDIATRIC T-ALL (~ 16%), ACUTE MYELOID LEUKEMIA (AML, ~ 3%), CHRONIC MYELOID LEUKEMIA (CML, ~ 2.5%), MIXED PHENOTYPE ACUTE LEUKEMIA (MPAL, ~ 20%), AND HIGH-GRADE B-CELL LYMPHOMA (HGBCL, ~ 3%). MORE RECENT STUDIES IMPLY AN ONCOGENIC EFFECT OF PHF6 IN B-CELL ACUTE LYMPHOBLASTIC LEUKEMIA (B-ALL) AND SOLID TUMORS. THESE DATA DEMONSTRATE THAT PHF6 COULD ACT AS A DOUBLE-EDGED SWORD, EITHER A TUMOR SUPPRESSOR OR AN ONCOGENE, IN A LINEAGE-DEPENDENT MANNER. HOWEVER, THE UNDERLYING MECHANISMS OF PHF6 IN NORMAL HEMATOPOIESIS AND LEUKEMOGENESIS REMAIN LARGELY UNKNOWN. IN THIS REVIEW, WE SUMMARIZE CURRENT KNOWLEDGE OF PHF6, EMPHASIZING THE ROLE OF PHF6 IN HEMATOLOGICAL MALIGNANCIES. EPIGENETIC REGULATION OF PHF6 IN B-ALL. PHF6 MAINTAINS A CHROMATIN STRUCTURE THAT IS PERMISSIVE TO B-CELL IDENTITY GENES, BUT NOT T-CELL-SPECIFIC GENES (LEFT). LOSS OF PHF6 LEADS TO ABERRANT EXPRESSION OF B-CELL- AND T-CELL-SPECIFIC GENES RESULTING FROM LINEAGE PROMISCUITY AND BINDING OF T-CELL TRANSCRIPTION FACTORS (RIGHT). 2023 6 422 30 ANNEXIN-A1 DEFICIENCY ATTENUATES STRESS-INDUCED TUMOR GROWTH VIA FATTY ACID METABOLISM IN MICE: AN INTEGRATED MULTIPLE OMICS ANALYSIS ON THE STRESS- MICROBIOME-METABOLITE-EPIGENETIC-ONCOLOGY (SMMEO) AXIS. BACKGROUND: HIGH EMOTIONAL OR PSYCHOPHYSICAL STRESS LEVELS HAVE BEEN CORRELATED WITH AN INCREASED RISK AND PROGRESSION OF VARIOUS DISEASES. HOW STRESS IMPACTS THE GUT MICROBIOTA TO INFLUENCE METABOLISM AND SUBSEQUENT CANCER PROGRESSION IS UNCLEAR. METHODS: FECES AND SERUM SAMPLES FROM BALB/C ANXA1(+/+) AND ANXA1(-/-) MICE WITH OR WITHOUT CHRONIC RESTRAINT STRESS WERE USED FOR 16S RRNA GENE SEQUENCING AND GC-MS METABOLOMICS ANALYSIS TO INVESTIGATE THE EFFECT OF STRESS ON MICROBIOME AND METABOLOMICS DURING STRESS AND BREAST TUMORIGENESIS. BREAST TUMORS SAMPLES FROM STRESSED AND NON-STRESSED MICE WERE USED TO PERFORM WHOLE-GENOME BISULFITE SEQUENCING (WGBS) AND RNASEQ ANALYSIS TO CONSTRUCT THE POTENTIAL NETWORK FROM CANDIDATE HUB GENES. FINALLY, MACHINE LEARNING AND INTEGRATED ANALYSIS WERE USED TO MAP THE AXIS FROM CHRONIC RESTRAINT STRESS TO BREAST CANCER DEVELOPMENT. RESULTS: WE REPORT THAT CHRONIC STRESS PROMOTES BREAST TUMOR GROWTH VIA A STRESS-MICROBIOME-METABOLITE-EPIGENETIC-ONCOLOGY (SMMEO) AXIS. CHRONIC RESTRAINT STRESS IN MICE ALTERS THE MICROBIOME COMPOSITION AND FATTY ACIDS METABOLISM AND INDUCES AN EPIGENETIC SIGNATURE IN TUMORS XENOGRAFTED AFTER STRESS. SUBSEQUENT MACHINE LEARNING AND SYSTEMIC MODELING ANALYSES IDENTIFIED A SIGNIFICANT CORRELATION AMONG MICROBIOME COMPOSITION, METABOLITES, AND DIFFERENTIALLY METHYLATED REGIONS IN STRESSED TUMORS. MOREOVER, SILENCING ANNEXIN-A1 INHIBITS THE CHANGES IN THE GUT MICROBIOME AND FATTY ACID METABOLISM AFTER STRESS AS WELL AS BASAL AND STRESS-INDUCED TUMOR GROWTH. CONCLUSIONS: THESE DATA SUPPORT A PHYSIOLOGICAL AXIS LINKING THE MICROBIOME AND METABOLITES TO CANCER EPIGENETICS AND INFLAMMATION. THE IDENTIFICATION OF THIS AXIS COULD PROPEL THE NEXT PHASE OF EXPERIMENTAL DISCOVERY IN FURTHER UNDERSTANDING THE UNDERLYING MOLECULAR MECHANISM OF TUMORIGENESIS CAUSED BY PHYSIOLOGICAL STRESS. 2022 7 326 31 ALLELIC SILENCING AT THE TUMOR-SUPPRESSOR LOCUS 13Q14.3 SUGGESTS AN EPIGENETIC TUMOR-SUPPRESSOR MECHANISM. GENOMIC MATERIAL FROM CHROMOSOME BAND 13Q14.3 DISTAL TO THE RETINOBLASTOMA LOCUS IS RECURRENTLY LOST IN A VARIETY OF HUMAN NEOPLASMS, INDICATING AN AS-YET-UNIDENTIFIED TUMOR-SUPPRESSOR MECHANISM. NO PATHOGENIC MUTATIONS HAVE BEEN FOUND IN THE MINIMALLY DELETED REGION UNTIL NOW. HOWEVER, IN B CELL CHRONIC LYMPHOCYTIC LEUKEMIA TUMORS WITH LOSS OF ONE COPY OF THE CRITICAL REGION, RESPECTIVE CANDIDATE TUMOR-SUPPRESSOR GENES ARE DOWN-REGULATED BY A FACTOR >2, WHICH WOULD BE EXPECTED BY A NORMAL GENE-DOSAGE EFFECT. THIS FINDING POINTS TO AN EPIGENETIC PATHOMECHANISM. WE FIND THAT THE TWO COPIES OF THE CRITICAL REGION REPLICATE ASYNCHRONOUSLY, SUGGESTING DIFFERENTIAL CHROMATIN PACKAGING OF THE TWO COPIES OF 13Q14.3. ALTHOUGH WE ALSO DETECT MONOALLELIC SILENCING OF GENES LOCALIZED IN THE CRITICAL REGION, MONOALLELIC EXPRESSION ORIGINATES FROM EITHER THE MATERNAL OR PATERNAL COPY, EXCLUDING AN IMPRINTING MECHANISM. DNA METHYLATION ANALYSES REVEALED ONE CPG ISLAND OF THE REGION TO BE METHYLATED. DNA DEMETHYLATION OF THIS CPG ISLAND AND GLOBAL HISTONE HYPERACETYLATION INDUCED BIALLELIC EXPRESSION, WHEREAS REPLICATION TIMING WAS NOT AFFECTED. WE PROPOSE THAT DIFFERENTIAL REPLICATION TIMING REPRESENTS AN EARLY EPIGENETIC MARK THAT DISTINGUISHES THE TWO COPIES OF 13Q14.3, RESULTING IN DIFFERENTIAL CHROMATIN PACKAGING AND MONOALLELIC EXPRESSION. ACCORDINGLY, DELETION OF THE SINGLE ACTIVE COPY OF 13Q14.3 RESULTS IN SIGNIFICANT DOWN-REGULATION OF THE CANDIDATE GENES AND LOSS OF FUNCTION, PROVIDING A MODEL FOR THE INTERACTION OF GENETIC LESIONS AND EPIGENETIC SILENCING AT 13Q14.3 IN B CELL CHRONIC LYMPHOCYTIC LEUKEMIA. 2006 8 901 20 CHRONIC EXPOSURE TO ANTHROPOGENIC AND CLIMATE RELATED STRESSORS ALTERS TRANSCRIPTIONAL RESPONSES IN THE LIVER OF ZEBRAFISH (DANIO RERIO) ACROSS MULTIPLE GENERATIONS. THE ANTIDEPRESSANT, VENLAFAXINE (VFX), AND CLIMATE CHANGE STRESSORS, SUCH AS INCREASED WATER TEMPERATURE AND DECREASED DISSOLVED OXYGEN, ARE CURRENT THREATS TO AQUATIC ENVIRONMENTS. THIS STUDY AIMED TO DETERMINE HOW MICRORNAS (MIRNAS) AND PREDICTED TARGETED TRANSCRIPTS WERE ALTERED IN LIVERS OF ZEBRAFISH EXPOSED TO THESE STRESSORS, AND LIVERS OF THEIR UN-EXPOSED F(1) AND F(2) OFFSPRING. FOLLOWING A 21 DAY EXPOSURE TO MULTIPLE STRESSORS (1 MUG/L VFX, +5 DEGREES C AMBIENT, 50% O(2)), THEN A SUBSEQUENT 21 DAY RECOVERY, RELATIVE ABUNDANCES OF CYP3A65, HSP70, HSP90, AND PPARGC1A AND MIRNAS PREDICTED TO TARGET THEM (MIR-142A, MIR-16C, MIR-181C, AND MIR-129, RESPECTIVELY) WERE MEASURED IN THE LIVER VIA QUANTITATIVE PCR (RT-QPCR). THERE WERE SIGNIFICANT DECREASES IN MIR-142A IN THE EXPOSED F(0) GENERATION AND THE EXPOSED F(1) GENERATION. WHILE THERE WERE NO CHANGES DETECTED IN CYP3A65 RELATIVE ABUNDANCE, THERE WAS A SIGNIFICANT INVERSE RELATIONSHIP BETWEEN CYP3A65 AND MIR-142A. HSP70 EXPRESSION SIGNIFICANTLY INCREASED IN THE F(1) GENERATION, WHICH PERSISTED TO THE F(2) GENERATION AND THE RELATIVE ABUNDANCE OF HSP90 SIGNIFICANTLY INCREASED IN ALL GENERATIONS. THERE WAS A SIGNIFICANT REDUCTION IN MIR-181C IN THE F(1) GENERATION, BUT THERE WAS NO SIGNIFICANT RELATIONSHIP BETWEEN MIR-181C AND HSP90. FINALLY, THERE WAS A SIGNIFICANT DECREASE IN PPARGC1A RELATIVE ABUNDANCE IN THE F(1) GENERATION WHICH WAS ASSOCIATED WITH AN INCREASE IN MIR-129. COMBINED, THESE RESULTS SUGGEST THAT PARENTAL EXPOSURE TO MULTIPLE, ENVIRONMENTALLY RELEVANT STRESSORS CAN CONFER TRANSCRIPTIONAL AND EPIGENETIC RESPONSES IN THE F(1) AND F(2) GENERATIONS, ALTHOUGH IDENTIFYING WHICH STRESSOR IS A DRIVING FORCE BECOMES UNCLEAR. 2021 9 2637 24 EPIGENOME-WIDE STUDY IDENTIFIES EPIGENETIC OUTLIERS IN NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. NONGENETIC PREDISPOSITION TO COLORECTAL CANCER CONTINUES TO BE DIFFICULT TO MEASURE PRECISELY, HAMPERING EFFORTS IN TARGETED PREVENTION AND SCREENING. EPIGENETIC CHANGES IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER CAN SERVE AS A TOOL IN PREDICTING COLORECTAL CANCER OUTCOMES. WE IDENTIFIED EPIGENETIC CHANGES AFFECTING THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. DNA METHYLATION PROFILING ON NORMAL COLON MUCOSA FROM 77 PATIENTS WITH COLORECTAL CANCER AND 68 CONTROLS IDENTIFIED A DISTINCT SUBGROUP OF NORMALLY-APPEARING MUCOSA WITH MARKEDLY DISRUPTED DNA METHYLATION AT A LARGE NUMBER OF CPGS, TERMED AS "OUTLIER METHYLATION PHENOTYPE" (OMP) AND ARE PRESENT IN 15 OF 77 PATIENTS WITH CANCER VERSUS 0 OF 68 CONTROLS (P < 0.001). SIMILAR FINDINGS WERE ALSO SEEN IN PUBLICLY AVAILABLE DATASETS. COMPARISON OF NORMAL COLON MUCOSA TRANSCRIPTION PROFILES OF PATIENTS WITH OMP CANCER WITH THOSE OF PATIENTS WITH NON-OMP CANCER INDICATES GENES WHOSE PROMOTERS ARE HYPERMETHYLATED IN THE OMP PATIENTS ARE ALSO TRANSCRIPTIONALLY DOWNREGULATED, AND THAT MANY OF THE GENES MOST AFFECTED ARE INVOLVED IN INTERACTIONS BETWEEN EPITHELIAL CELLS, THE MUCUS LAYER, AND THE MICROBIOME. ANALYSIS OF 16S RRNA PROFILES SUGGESTS THAT NORMAL COLON MUCOSA OF OMPS ARE ENRICHED IN BACTERIAL GENERA ASSOCIATED WITH COLORECTAL CANCER RISK, ADVANCED TUMOR STAGE, CHRONIC INTESTINAL INFLAMMATION, MALIGNANT TRANSFORMATION, NOSOCOMIAL INFECTIONS, AND KRAS MUTATIONS. IN CONCLUSION, OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. PROSPECTIVE STUDIES ARE NEEDED TO DETERMINE WHETHER OMP COULD SERVE AS A BIOMARKER FOR AN ELEVATED EPIGENETIC RISK FOR COLORECTAL CANCER DEVELOPMENT. PREVENTION RELEVANCE: OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. IDENTIFICATION OF OMPS IN HEALTHY CONTROLS AND PATIENTS WITH COLORECTAL CANCER WILL LEAD TO PREVENTION AND BETTER PROGNOSIS, RESPECTIVELY. 2022 10 66 23 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 11 4254 37 METHYLOME-BASED CELL-OF-ORIGIN MODELING (METHYL-COOM) IDENTIFIES ABERRANT EXPRESSION OF IMMUNE REGULATORY MOLECULES IN CLL. BACKGROUND: IN CANCER, NORMAL EPIGENETIC PATTERNS ARE DISTURBED AND CONTRIBUTE TO GENE EXPRESSION CHANGES, DISEASE ONSET, AND PROGRESSION. THE CANCER EPIGENOME IS COMPOSED OF THE EPIGENETIC PATTERNS PRESENT IN THE TUMOR-INITIATING CELL AT THE TIME OF TRANSFORMATION, AND THE TUMOR-SPECIFIC EPIGENETIC ALTERATIONS THAT ARE ACQUIRED DURING TUMOR INITIATION AND PROGRESSION. THE PRECISE DISSECTION OF THESE TWO COMPONENTS OF THE TUMOR EPIGENOME WILL FACILITATE A BETTER UNDERSTANDING OF THE BIOLOGICAL MECHANISMS UNDERLYING MALIGNANT TRANSFORMATION. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) ORIGINATES FROM DIFFERENTIATING B CELLS, WHICH UNDERGO EXTENSIVE EPIGENETIC PROGRAMMING. THIS POSES THE CHALLENGE TO PRECISELY DETERMINE THE EPIGENOMIC GROUND STATE OF THE CELL-OF-ORIGIN IN ORDER TO IDENTIFY CLL-SPECIFIC EPIGENETIC ABERRATIONS. METHODS: WE DEVELOPED A LINEAR REGRESSION MODEL, METHYLOME-BASED CELL-OF-ORIGIN MODELING (METHYL-COOM), TO MAP THE CELL-OF-ORIGIN FOR INDIVIDUAL CLL PATIENTS BASED ON THE CONTINUUM OF EPIGENOMIC CHANGES DURING NORMAL B CELL DIFFERENTIATION. RESULTS: METHYL-COOM ACCURATELY MAPS THE CELL-OF-ORIGIN OF CLL AND IDENTIFIES CLL-SPECIFIC ABERRANT DNA METHYLATION EVENTS THAT ARE NOT CONFOUNDED BY PHYSIOLOGIC EPIGENETIC B CELL PROGRAMMING. FURTHERMORE, METHYL-COOM UNMASKS ABNORMAL ACTION OF TRANSCRIPTION FACTORS, ALTERED SUPER-ENHANCER ACTIVITIES, AND ABERRANT TRANSCRIPT EXPRESSION IN CLL. AMONG THE ABERRANTLY REGULATED TRANSCRIPTS WERE MANY GENES THAT HAVE PREVIOUSLY BEEN IMPLICATED IN T CELL BIOLOGY. FLOW CYTOMETRY ANALYSIS OF THESE MARKERS CONFIRMED THEIR ABERRANT EXPRESSION ON MALIGNANT B CELLS AT THE PROTEIN LEVEL. CONCLUSIONS: METHYL-COOM ANALYSIS OF CLL IDENTIFIED DISEASE-SPECIFIC ABERRANT GENE REGULATION. THE ABERRANTLY EXPRESSED GENES IDENTIFIED IN THIS STUDY MIGHT PLAY A ROLE IN IMMUNE-EVASION IN CLL AND MIGHT SERVE AS NOVEL TARGETS FOR IMMUNOTHERAPY APPROACHES. IN SUMMARY, WE PROPOSE A NOVEL FRAMEWORK FOR IN SILICO MODELING OF REFERENCE DNA METHYLOMES AND FOR THE IDENTIFICATION OF CANCER-SPECIFIC EPIGENETIC CHANGES, A CONCEPT THAT CAN BE BROADLY APPLIED TO OTHER HUMAN MALIGNANCIES. 2020 12 5121 17 POSSIBLE IMPRINTING AND MICROCHIMERISM IN CHRONIC LYMPHOCYTIC LEUKEMIA AND RELATED LYMPHOPROLIFERATIVE DISORDERS. BASED ON THE CONCEPT THAT THE TUMOROGENESIS IN CHRONIC LYMPHOCYTIC LEUKAEMIA COMPRISES BOTH AN INITIAL, INHERITED MUTATION AND SUBSEQUENT SOMATIC MUTATIONS, THE PLEIOTYPIC DIVERSITY OF FAMILIAL CHRONIC LYMPHOCYTIC LEUKAEMIA AND RELATED MALIGNANT LYMPHOPROLIFERATIVE DISORDERS IS GENERALLY EXPLAINED BY A REPERTOIRE OF MONOALLELIC POLYGENES IN THE INITIAL MUTATION. EPIGENETIC GENOMIC IMPRINTING IS A LIKELY MECHANISM BEHIND OF THE ASYNCHRONEOUS REPLICATING MONOALLELIC POLYGENES WHICH IS DISCUSSED IN THE LIGHT OF PLEIOTROPHY AND BIRTH ORDER EFFECT. FURTHERMORE, IT IS DISCUSSED THAT ONE POSSIBLE MECHANISM AVAILABLE FOR THE EPIGENETIC TRANSFER OF THESE GENES COULD BE THE PHYSIOLOGICAL PREGNANCY-RELATED MICROCHIMERISM BETWEEN MOTHER AND FETUS. 2008 13 709 30 C-MYC ONCOPROTEIN DICTATES TRANSCRIPTIONAL PROFILES OF ATP-BINDING CASSETTE TRANSPORTER GENES IN CHRONIC MYELOGENOUS LEUKEMIA CD34+ HEMATOPOIETIC PROGENITOR CELLS. RESISTANCE TO CHEMOTHERAPEUTIC AGENTS REMAINS ONE OF THE MAJOR IMPEDIMENTS TO A SUCCESSFUL TREATMENT OF CHRONIC MYELOID LEUKEMIA (CML). MISREGULATION OF THE ACTIVITY OF A SPECIFIC GROUP OF ATP-BINDING CASSETTE TRANSPORTERS (ABC) IS RESPONSIBLE FOR REDUCING THE INTRACELLULAR CONCENTRATION OF DRUGS IN LEUKEMIC CELLS. MOREOVER, A CONSISTENT BODY OF EVIDENCE ALSO SUGGESTS THAT ABC TRANSPORTERS PLAY A ROLE IN CANCER PROGRESSION BEYOND THE EFFLUX OF CYTOTOXIC DRUGS. DESPITE A LARGE NUMBER OF STUDIES THAT INVESTIGATED THE FUNCTION OF THE ABC TRANSPORTERS, LITTLE IS KNOWN ABOUT THE TRANSCRIPTIONAL REGULATION OF THE ABC GENES. HERE, WE PRESENT DATA SHOWING THAT THE ONCOPROTEIN C-MYC IS A DIRECT TRANSCRIPTIONAL REGULATOR OF A LARGE SET OF ABC TRANSPORTERS IN CML. FURTHERMORE, MOLECULAR ANALYSIS CARRIED OUT IN CD34+ HEMATOPOIETIC CELL PRECURSORS OF 21 CML PATIENTS REVEALS THAT THE OVEREXPRESSION OF ABC TRANSPORTERS DRIVEN BY C-MYC IS A PECULIAR CHARACTERISTIC OF THE CD34+ POPULATION IN CML AND WAS NOT FOUND EITHER IN THE POPULATION OF MONONUCLEAR CELLS FROM WHICH THEY HAD BEEN PURIFIED NOR IN CD34+ CELLS ISOLATED FROM HEALTHY DONORS. FINALLY, WE DESCRIBE HOW THE METHYLATION STATE OF CPG ISLANDS MAY REGULATE THE ACCESS OF C-MYC TO ABCG2 GENE PROMOTER, A WELL-STUDIED GENE ASSOCIATED WITH MULTIDRUG RESISTANCE IN CML, HENCE, AFFECTING ITS EXPRESSION. TAKEN TOGETHER, OUR FINDINGS SUPPORT A MODEL IN WHICH C-MYC-DRIVEN TRANSCRIPTIONAL EVENTS, COMBINED WITH EPIGENETIC MECHANISMS, DIRECT AND REGULATE THE EXPRESSION OF ABC GENES WITH POSSIBLE IMPLICATIONS IN TUMOR MALIGNANCY AND DRUG EFFLUX IN CML. 2011 14 2481 34 EPIGENETIC UPREGULATION OF LNCRNAS AT 13Q14.3 IN LEUKEMIA IS LINKED TO THE IN CIS DOWNREGULATION OF A GENE CLUSTER THAT TARGETS NF-KB. NON-CODING RNAS ARE MUCH MORE COMMON THAN PREVIOUSLY THOUGHT. HOWEVER, FOR THE VAST MAJORITY OF NON-CODING RNAS, THE CELLULAR FUNCTION REMAINS ENIGMATIC. THE TWO LONG NON-CODING RNA (LNCRNA) GENES DLEU1 AND DLEU2 MAP TO A CRITICAL REGION AT CHROMOSOMAL BAND 13Q14.3 THAT IS RECURRENTLY DELETED IN SOLID TUMORS AND HEMATOPOIETIC MALIGNANCIES LIKE CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). WHILE NO POINT MUTATIONS HAVE BEEN FOUND IN THE PROTEIN CODING CANDIDATE GENES AT 13Q14.3, THEY ARE DEREGULATED IN MALIGNANT CELLS, SUGGESTING AN EPIGENETIC TUMOR SUPPRESSOR MECHANISM. WE THEREFORE CHARACTERIZED THE EPIGENETIC MAKEUP OF 13Q14.3 IN CLL CELLS AND FOUND HISTONE MODIFICATIONS BY CHROMATIN-IMMUNOPRECIPITATION (CHIP) THAT ARE ASSOCIATED WITH ACTIVATED TRANSCRIPTION AND SIGNIFICANT DNA-DEMETHYLATION AT THE TRANSCRIPTIONAL START SITES OF DLEU1 AND DLEU2 USING 5 DIFFERENT SEMI-QUANTITATIVE AND QUANTITATIVE METHODS (APRIMES, BIOCOBRA, MCIP, MASSARRAY, AND BISULFITE SEQUENCING). THESE EPIGENETIC ABERRATIONS WERE CORRELATED WITH TRANSCRIPTIONAL DEREGULATION OF THE NEIGHBORING CANDIDATE TUMOR SUPPRESSOR GENES, SUGGESTING A COREGULATION IN CIS OF THIS GENE CLUSTER. WE FOUND THAT THE 13Q14.3 GENES IN ADDITION TO THEIR PREVIOUSLY KNOWN FUNCTIONS REGULATE NF-KB ACTIVITY, WHICH WE COULD SHOW AFTER OVEREXPRESSION, SIRNA-MEDIATED KNOCKDOWN, AND DOMINANT-NEGATIVE MUTANT GENES BY USING WESTERN BLOTS WITH PREVIOUSLY UNDESCRIBED ANTIBODIES, BY A CUSTOMIZED ELISA AS WELL AS BY REPORTER ASSAYS. IN ADDITION, WE PERFORMED AN UNBIASED SCREEN OF 810 HUMAN MIRNAS AND IDENTIFIED THE MIR-15/16 FAMILY OF GENES AT 13Q14.3 AS THE STRONGEST INDUCERS OF NF-KB ACTIVITY. IN SUMMARY, THE TUMOR SUPPRESSOR MECHANISM AT 13Q14.3 IS A CLUSTER OF GENES CONTROLLED BY TWO LNCRNA GENES THAT ARE REGULATED BY DNA-METHYLATION AND HISTONE MODIFICATIONS AND WHOSE MEMBERS ALL REGULATE NF-KB. THEREFORE, THE TUMOR SUPPRESSOR MECHANISM IN 13Q14.3 UNDERLINES THE ROLE BOTH OF EPIGENETIC ABERRATIONS AND OF LNCRNA GENES IN HUMAN TUMORIGENESIS AND IS AN EXAMPLE OF COLOCALIZATION OF A FUNCTIONALLY RELATED GENE CLUSTER. 2013 15 4004 29 LOSS OF THE POLYCOMB MARK FROM BIVALENT PROMOTERS LEADS TO ACTIVATION OF CANCER-PROMOTING GENES IN COLORECTAL TUMORS. IN COLON TUMORS, THE TRANSCRIPTION OF MANY GENES BECOMES DEREGULATED BY POORLY DEFINED EPIGENETIC MECHANISMS THAT HAVE BEEN STUDIED MAINLY IN ESTABLISHED CELL LINES. IN THIS STUDY, WE USED FROZEN HUMAN COLON TISSUES TO ANALYZE PATTERNS OF HISTONE MODIFICATION AND DNA CYTOSINE METHYLATION IN CANCER AND MATCHED NORMAL MUCOSA SPECIMENS. DNA METHYLATION IS STRONGLY TARGETED TO BIVALENT H3K4ME3- AND H3K27ME3-ASSOCIATED PROMOTERS, WHICH LOSE BOTH HISTONE MARKS AND ACQUIRE DNA METHYLATION. HOWEVER, WE FOUND THAT LOSS OF THE POLYCOMB MARK H3K27ME3 FROM BIVALENT PROMOTERS WAS ACCOMPANIED OFTEN BY ACTIVATION OF GENES ASSOCIATED WITH CANCER PROGRESSION, INCLUDING NUMEROUS STEM CELL REGULATORS, ONCOGENES, AND PROLIFERATION-ASSOCIATED GENES. INDEED, WE FOUND MANY OF THESE SAME GENES WERE ALSO ACTIVATED IN PATIENTS WITH ULCERATIVE COLITIS WHERE CHRONIC INFLAMMATION PREDISPOSES THEM TO COLON CANCER. BASED ON OUR FINDINGS, WE PROPOSE THAT A LOSS OF POLYCOMB REPRESSION AT BIVALENT GENES COMBINED WITH AN ENSUING SELECTION FOR TUMOR-DRIVING EVENTS PLAYS A MAJOR ROLE IN CANCER PROGRESSION. 2014 16 1656 24 DOUBLE STRAND BREAKS CAN INITIATE GENE SILENCING AND SIRT1-DEPENDENT ONSET OF DNA METHYLATION IN AN EXOGENOUS PROMOTER CPG ISLAND. CHRONIC EXPOSURE TO INDUCERS OF DNA BASE OXIDATION AND SINGLE AND DOUBLE STRAND BREAKS CONTRIBUTE TO TUMORIGENESIS. IN ADDITION TO THE GENETIC CHANGES CAUSED BY THIS DNA DAMAGE, SUCH TUMORS OFTEN CONTAIN EPIGENETICALLY SILENCED GENES WITH ABERRANT PROMOTER REGION CPG ISLAND DNA HYPERMETHYLATION. WE HEREIN EXPLORE THE RELATIONSHIPS BETWEEN SUCH DNA DAMAGE AND EPIGENETIC GENE SILENCING USING AN EXPERIMENTAL MODEL IN WHICH WE INDUCE A DEFINED DOUBLE STRAND BREAK IN AN EXOGENOUS PROMOTER CONSTRUCT OF THE E-CADHERIN CPG ISLAND, WHICH IS FREQUENTLY ABERRANTLY DNA HYPERMETHYLATED IN EPITHELIAL CANCERS. FOLLOWING THE ONSET OF REPAIR OF THE BREAK, WE OBSERVE RECRUITMENT TO THE SITE OF DAMAGE OF KEY PROTEINS INVOLVED IN ESTABLISHING AND MAINTAINING TRANSCRIPTIONAL REPRESSION, NAMELY SIRT1, EZH2, DNMT1, AND DNMT3B, AND THE APPEARANCE OF THE SILENCING HISTONE MODIFICATIONS, HYPOACETYL H4K16, H3K9ME2 AND ME3, AND H3K27ME3. ALTHOUGH IN MOST CELLS SELECTED AFTER THE BREAK, DNA REPAIR OCCURS FAITHFULLY WITH PRESERVATION OF ACTIVITY OF THE PROMOTER, A SMALL PERCENTAGE OF THE PLATED CELLS DEMONSTRATE INDUCTION OF HERITABLE SILENCING. THE CHROMATIN AROUND THE BREAK SITE IN SUCH A SILENT CLONE IS ENRICHED FOR MOST OF THE ABOVE SILENT CHROMATIN PROTEINS AND HISTONE MARKS, AND THE REGION HARBORS THE APPEARANCE OF INCREASING DNA METHYLATION IN THE CPG ISLAND OF THE PROMOTER. DURING THE ACUTE BREAK, SIRT1 APPEARS TO BE REQUIRED FOR THE TRANSIENT RECRUITMENT OF DNMT3B AND SUBSEQUENT METHYLATION OF THE PROMOTER IN THE SILENT CLONES. TAKEN TOGETHER, OUR DATA SUGGEST THAT NORMAL REPAIR OF A DNA BREAK CAN OCCASIONALLY CAUSE HERITABLE SILENCING OF A CPG ISLAND-CONTAINING PROMOTER BY RECRUITMENT OF PROTEINS INVOLVED IN SILENCING. FURTHERMORE, WITH CONTRIBUTION OF THE STRESS-RELATED PROTEIN SIRT1, THE BREAK CAN LEAD TO THE ONSET OF ABERRANT CPG ISLAND DNA METHYLATION, WHICH IS FREQUENTLY ASSOCIATED WITH TIGHT GENE SILENCING IN CANCER. 2008 17 390 23 AN INTEGRATIVE MODEL OF PATHWAY CONVERGENCE IN GENETICALLY HETEROGENEOUS BLAST CRISIS CHRONIC MYELOID LEUKEMIA. TARGETED THERAPIES AGAINST THE BCR-ABL1 KINASE HAVE REVOLUTIONIZED TREATMENT OF CHRONIC PHASE (CP) CHRONIC MYELOID LEUKEMIA (CML). IN CONTRAST, MANAGEMENT OF BLAST CRISIS (BC) CML REMAINS CHALLENGING BECAUSE BC CELLS ACQUIRE COMPLEX MOLECULAR ALTERATIONS THAT CONFER STEMNESS FEATURES TO PROGENITOR POPULATIONS AND RESISTANCE TO BCR-ABL1 TYROSINE KINASE INHIBITORS. COMPREHENSIVE MODELS OF BC TRANSFORMATION HAVE PROVED ELUSIVE BECAUSE OF THE RARITY AND GENETIC HETEROGENEITY OF BC, BUT ARE IMPORTANT FOR DEVELOPING BIOMARKERS PREDICTING BC PROGRESSION AND EFFECTIVE THERAPIES. TO BETTER UNDERSTAND BC, WE PERFORMED AN INTEGRATED MULTIOMICS ANALYSIS OF 74 CP AND BC SAMPLES USING WHOLE-GENOME AND EXOME SEQUENCING, TRANSCRIPTOME AND METHYLOME PROFILING, AND CHROMATIN IMMUNOPRECIPITATION FOLLOWED BY HIGH-THROUGHPUT SEQUENCING. EMPLOYING PATHWAY-BASED ANALYSIS, WE FOUND THE BC GENOME WAS SIGNIFICANTLY ENRICHED FOR MUTATIONS AFFECTING COMPONENTS OF THE POLYCOMB REPRESSIVE COMPLEX (PRC) PATHWAY. WHILE TRANSCRIPTOMICALLY, BC PROGENITORS WERE ENRICHED AND DEPLETED FOR PRC1- AND PRC2-RELATED GENE SETS RESPECTIVELY. BY INTEGRATING OUR DATA SETS, WE DETERMINED THAT BC PROGENITORS UNDERGO PRC-DRIVEN EPIGENETIC REPROGRAMMING TOWARD A CONVERGENT TRANSCRIPTOMIC STATE. SPECIFICALLY, PRC2 DIRECTS BC DNA HYPERMETHYLATION, WHICH IN TURN SILENCES KEY GENES INVOLVED IN MYELOID DIFFERENTIATION AND TUMOR SUPPRESSOR FUNCTION VIA SO-CALLED EPIGENETIC SWITCHING, WHEREAS PRC1 REPRESSES AN OVERLAPPING AND DISTINCT SET OF GENES, INCLUDING NOVEL BC TUMOR SUPPRESSORS. ON THE BASIS OF THESE OBSERVATIONS, WE DEVELOPED AN INTEGRATED MODEL OF BC THAT FACILITATED THE IDENTIFICATION OF COMBINATORIAL THERAPIES CAPABLE OF REVERSING BC REPROGRAMMING (DECITABINE+PRC1 INHIBITORS), NOVEL PRC-SILENCED TUMOR SUPPRESSOR GENES (NR4A2), AND GENE EXPRESSION SIGNATURES PREDICTIVE OF DISEASE PROGRESSION AND DRUG RESISTANCE IN CP. 2020 18 83 23 A NOVEL EPIGENETIC MARKER, TEN-ELEVEN TRANSLOCATION FAMILY MEMBER 2 (TET2), IS IDENTIFIED IN THE INTRACTABLE EPILEPTIC BRAIN AND REGULATES ATP BINDING CASSETTE SUBFAMILY B MEMBER 1 (ABCB1) IN THE BLOOD-BRAIN BARRIER. DRUG-RESISTANT EPILEPSY (DRE) IS A CHRONIC CONDITION DERIVED FROM SPONTANEOUS CHANGES AND REGULATORY EFFECTS IN THE EPILEPTIC BRAIN. AS DEMETHYLATION FACTORS, TEN-ELEVEN TRANSLOCATION (TET) FAMILY MEMBERS HAVE BECOME A FOCUS IN RECENT STUDIES OF NEUROLOGICAL DISORDERS. HERE, WE QUANTIFIED AND LOCALIZED TET1, TET2 AND 5-HYDROXYMETHYLCYTOSINE (5-HMC) IN THE TEMPORAL LOBE CORTEX OF DRE PATIENTS (N = 27) AND TRAUMATIC BRAIN HEMORRHAGE CONTROLS (N = 10) BY IMMUNOCHEMICAL STAINING. TET2 AND ATP BINDING CASSETTE SUBFAMILY B MEMBER 1 (ABCB1) EXPRESSION PATTERNS WERE DETERMINED IN THE ISOLATED BRAIN CAPILLARIES OF DRE PATIENTS. TET2 EXPRESSION WAS SIGNIFICANTLY INCREASED IN THE TEMPORAL CORTICAL TISSUE OF DRE PATIENTS WITH OR WITHOUT HIPPOCAMPAL SCLEROSIS (HS) COMPARED TO CONTROL PATIENTS, WHILE TET1 AND 5-HMC SHOWED NO DIFFERENCES IN EXPRESSION. WE ALSO FOUND THAT A PARTICULARLY STRONG EXPRESSION OF TET2 IN THE VASCULAR TISSUE OF DRE PATIENTS. ABCB1 AND TET2 HAVE EVIDENTLY HIGHER EXPRESSION IN THE VASCULAR ENDOTHELIUM FROM THE NEOCORTEX OF DRE PATIENTS. IN BLOOD-BRAIN BARRIER (BBB) MODEL, TET2 DEPLETION CAN CAUSE ATTENUATED EXPRESSION AND FUNCTION OF ABCB1. DATA FROM A COHORT STUDY AND EXPERIMENTS IN A BBB MODEL SUGGEST THAT TET2 HAS A SPECIFIC REGULATORY EFFECT ON ABCB1, WHICH MAY SERVE AS A POTENTIAL MECHANISM AND TARGET IN DRE. 2022 19 2928 23 GENERATION OF IPSCS FROM CULTURED HUMAN MALIGNANT CELLS. INDUCED PLURIPOTENT STEM CELLS (IPSCS) CAN BE GENERATED FROM VARIOUS DIFFERENTIATED CELL TYPES BY THE EXPRESSION OF A SET OF DEFINED TRANSCRIPTION FACTORS. SO FAR, IPSCS HAVE BEEN GENERATED FROM PRIMARY CELLS, BUT IT IS UNCLEAR WHETHER HUMAN CANCER CELL LINES CAN BE REPROGRAMMED. HERE WE DESCRIBE THE GENERATION AND CHARACTERIZATION OF IPSCS DERIVED FROM HUMAN CHRONIC MYELOID LEUKEMIA CELLS. WE SHOW THAT, DESPITE THE PRESENCE OF ONCOGENIC MUTATIONS, THESE CELLS ACQUIRED PLURIPOTENCY BY THE EXPRESSION OF 4 TRANSCRIPTION FACTORS AND UNDERWENT DIFFERENTIATION INTO CELL TYPES DERIVED OF ALL 3 GERM LAYERS DURING TERATOMA FORMATION. INTERESTINGLY, ALTHOUGH THE PARENTAL CELL LINE WAS STRICTLY DEPENDENT ON CONTINUOUS SIGNALING OF THE BCR-ABL ONCOGENE, ALSO TERMED ONCOGENE ADDICTION, REPROGRAMMED CELLS LOST THIS DEPENDENCY AND BECAME RESISTANT TO THE BCR-ABL INHIBITOR IMATINIB. THIS FINDING INDICATES THAT THE THERAPEUTIC AGENT IMATINIB TARGETS CELLS IN A SPECIFIC EPIGENETIC DIFFERENTIATED CELL STATE, AND THIS MAY CONTRIBUTE TO ITS INABILITY TO FULLY ERADICATE DISEASE IN CHRONIC MYELOID LEUKEMIA PATIENTS. 2010 20 1620 24 DNA METHYLTRANSFERASE-MEDIATED TRANSCRIPTIONAL SILENCING IN MALIGNANT GLIOMA: A COMBINED WHOLE-GENOME MICROARRAY AND PROMOTER ARRAY ANALYSIS. EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IS A COMMON FEATURE IN HUMAN CANCER. PROMOTER HYPERMETHYLATION AND HISTONE DEACETYLATION ARE REVERSIBLE EPIGENETIC MECHANISMS ASSOCIATED WITH TRANSCRIPTIONAL REGULATION. DNA METHYLTRANSFERASES (DNMT1 AND DNMT3B) REGULATE AND MAINTAIN PROMOTER METHYLATION AND ARE OVEREXPRESSED IN HUMAN CANCER. WE PERFORMED WHOLE-GENOME MICROARRAY ANALYSIS TO IDENTIFY GENES WITH ALTERED EXPRESSION AFTER RNAI-INDUCED SUPPRESSION OF DNMT IN A GLIOBLASTOMA MULTIFORME (GBM) CELL LINE. WE THEN IDENTIFIED GENES WITH BOTH DECREASED EXPRESSION AND EVIDENCE OF PROMOTER CPG ISLAND HYPERMETHYLATION IN GBM TISSUE SAMPLES USING A COMBINED WHOLE-GENOME MICROARRAY TRANSCRIPTOME ANALYSIS IN CONJUNCTION WITH A PROMOTER ARRAY ANALYSIS AFTER DNA IMMUNOPRECIPITATION WITH ANTI-5-METHYLCYTIDINE. DNMT1 AND 3B KNOCKDOWN RESULTED IN THE RESTORED EXPRESSION OF 308 GENES THAT ALSO CONTAINED PROMOTER REGION HYPERMETHYLATION. OF THESE, 43 WERE ALSO FOUND TO BE DOWNREGULATED IN GBM TISSUE SAMPLES. THREE DOWNREGULATED GENES WITH HYPERMETHYLATED PROMOTERS AND RESTORED EXPRESSION IN RESPONSE TO ACUTE DNMT SUPPRESSION WERE ASSAYED FOR METHYLATION CHANGES USING BISULFITE SEQUENCE ANALYSIS OF THE PROMOTER REGION AFTER CHRONIC DNMT SUPPRESSION. RESTORATION OF GENE EXPRESSION WAS NOT ASSOCIATED WITH CHANGES IN PROMOTER REGION METHYLATION, BUT RATHER WITH CHANGES IN HISTONE METHYLATION AND CHROMATIN CONFORMATION. TWO OF THE IDENTIFIED GENES EXHIBITED GROWTH SUPPRESSIVE ACTIVITY IN IN VITRO ASSAYS. COMBINING TARGETED GENETIC MANIPULATIONS WITH COMPREHENSIVE GENOMIC AND EXPRESSION ANALYSES PROVIDES A POTENTIALLY POWERFUL NEW APPROACH FOR IDENTIFYING EPIGENETICALLY REGULATED GENES IN GBM. 2009