1 3615 129 IN VITRO FOLATE DEFICIENCY INDUCES DEOXYNUCLEOTIDE POOL IMBALANCE, APOPTOSIS, AND MUTAGENESIS IN CHINESE HAMSTER OVARY CELLS. THE GENETIC AND EPIGENETIC EFFECTS OF NUTRITIONAL FOLATE DEFICIENCY WERE STUDIED IN TWO CHINESE HAMSTER OVARY (CHO) CELL LINES. THE CHO-AA8 CELL LINE (HEMIZYGOUS AT THE APRT LOCUS) AND CHO-UV5 (DNA REPAIR-DEFICIENT MUTANT OF AA8) WERE CULTURED IN HAM'S F-12 MEDIUM OR IN CUSTOM-PREPARED HAM'S F-12 MEDIUM LACKING FOLIC ACID, THYMIDINE, AND HYPOXANTHINE. CELLS CULTURED ACUTELY IN THE FOLATE DEFICIENT MEDIUM EXHIBITED INITIAL GROWTH ARREST, FOLLOWED BY MASSIVE CELL DEATH AND DNA FRAGMENTATION INTO NUCLEOSOMAL MULTIMERS CHARACTERISTIC OF APOPTOSIS. ALTHOUGH PROLONGED CULTURE IN THE FOLATE DEFICIENT MEDIUM WAS CYTOSTATIC AND LETHAL TO THE MAJORITY CELLS, MINOR SUBPOPULATIONS IN BOTH CELL LINES FAILED TO INITIATE CELL DEATH, EXHIBITED PHENOTYPIC ABNORMALITIES, AND ADAPTED A SELECTIVE GROWTH ADVANTAGE UNDER MARGINAL FOLATE CONDITIONS. THESE "RESISTANT" CLONES EXHIBITED MAJOR ALTERATIONS IN DEOXYNUCLEOTIDE POOLS ASSOCIATED WITH AN INCREASE IN MUTANT FREQUENCY AT THE APRT LOCUS AS DETECTED BY RESISTANCE TO CYTOTOXICITY IN 8-AZAADENOSINE. THE MUTATION FREQUENCY IN THE DNA REPAIR-DEFICIENT CHO-UV5 CELLS WAS APPROXIMATELY 100-FOLD GREATER THAN THAT IN THE PARENTAL AA8 CLONES, UNDERSCORING THE IMPORTANCE OF DNA REPAIR UNDER CONDITIONS OF FOLATE DEFICIENCY AND NUCLEOTIDE POOL IMBALANCE. THE ENHANCED MUTATION FREQUENCY IN THE DNA REPAIR-COMPETENT FOLATE-DEFICIENT CHO-AA8 CELLS SUGGESTS THAT DNA REPAIR ACTIVITY IS LESS EFFECTIVE UNDER FOLATE-DEFICIENT CONDITIONS. THESE RESULTS ADD TO THE ACCUMULATING CLINICAL AND EXPERIMENTAL EVIDENCE RELATING CHRONIC FOLATE DEFICIENCY TO GENOMIC INSTABILITY AND CARCINOGENESIS. 1994 2 4556 17 MUTATIONAL SPECTRUM OF MYELOID MALIGNANCIES WITH INV(3)/T(3;3) REVEALS A PREDOMINANT INVOLVEMENT OF RAS/RTK SIGNALING PATHWAYS. MYELOID MALIGNANCIES BEARING CHROMOSOMAL INV(3)/T(3;3) ABNORMALITIES ARE AMONG THE MOST THERAPY-RESISTANT LEUKEMIAS. DEREGULATED EXPRESSION OF EVI1 IS THE MOLECULAR HALLMARK OF THIS DISEASE; HOWEVER, THE GENOME-WIDE SPECTRUM OF COOPERATING MUTATIONS IN THIS DISEASE SUBSET HAS NOT BEEN SYSTEMATICALLY ELUCIDATED. HERE, WE SHOW THAT 98% OF INV(3)/T(3;3) MYELOID MALIGNANCIES HARBOR MUTATIONS IN GENES ACTIVATING RAS/RECEPTOR TYROSINE KINASE (RTK) SIGNALING PATHWAYS. IN ADDITION, HEMIZYGOUS MUTATIONS IN GATA2, AS WELL AS HETEROZYGOUS ALTERATIONS IN RUNX1, SF3B1, AND GENES ENCODING EPIGENETIC MODIFIERS, FREQUENTLY CO-OCCUR WITH THE INV(3)/T(3;3) ABERRATION. NOTABLY, NEITHER MUTATIONAL PATTERNS NOR GENE EXPRESSION PROFILES DIFFER ACROSS INV(3)/T(3;3) ACUTE MYELOID LEUKEMIA, CHRONIC MYELOID LEUKEMIA, AND MYELODYSPLASTIC SYNDROME CASES, SUGGESTING RECOGNITION OF INV(3)/T(3;3) MYELOID MALIGNANCIES AS A SINGLE DISEASE ENTITY IRRESPECTIVE OF BLAST COUNT. THE HIGH INCIDENCE OF ACTIVATING RAS/RTK SIGNALING MUTATIONS MAY PROVIDE A TARGET FOR A RATIONAL TREATMENT STRATEGY IN THIS HIGH-RISK PATIENT GROUP. 2015 3 5608 24 RUNX1-EVI1 DISRUPTS LINEAGE DETERMINATION AND THE CELL CYCLE BY INTERFERING WITH RUNX1 AND EVI1 DRIVEN GENE REGULATORY NETWORKS. HEMATOLOGICAL MALIGNANCIES ARE CHARACTERISED BY A BLOCK IN DIFFERENTIATION, WHICH IN MANY CASES IS CAUSED BY RECURRENT MUTATIONS AFFECTING THE ACTIVITY OF HEMATOPOIETIC TRANSCRIPTION FACTORS. RUNX1-EVI1 IS A FUSION PROTEIN FORMED BY THE T(3;21) TRANSLOCATION LINKING TWO TRANSCRIPTION FACTORS REQUIRED FOR NORMAL HEMATOPOIESIS. RUNX1-EVI1 EXPRESSION IS FOUND IN MYELODYSPLASTIC SYNDROME, SECONDARY ACUTE MYELOID LEUKEMIA, AND BLAST CRISIS OF CHRONIC MYELOID LEUKEMIA; WITH CLINICAL OUTCOMES BEING WORSE THAN IN PATIENTS WITH RUNX1-ETO, RUNX1 OR EVI1 MUTATIONS ALONE. RUNX1-EVI1 IS USUALLY FOUND AS A SECONDARY MUTATION, THEREFORE THE MOLECULAR MECHANISMS UNDERLYING HOW RUNX1-EVI1 ALONE CONTRIBUTES TO POOR PROGNOSIS ARE UNKNOWN. TO ADDRESS THIS QUESTION, WE INDUCED EXPRESSION OF RUNX1-EVI1 IN HEMATOPOIETIC CELLS DERIVED FROM AN EMBRYONIC STEM CELL DIFFERENTIATION MODEL. INDUCTION RESULTED IN DISRUPTION OF THE RUNX1-DEPENDENT ENDOTHELIAL-HEMATOPOIETIC TRANSITION, BLOCKED THE CELL CYCLE AND UNDERMINED CELL FATE DECISIONS IN MULTIPOTENT HEMATOPOIETIC PROGENITOR CELLS. INTEGRATIVE ANALYSES OF GENE EXPRESSION WITH CHROMATIN AND TRANSCRIPTION FACTOR BINDING DATA DEMONSTRATED THAT RUNX1-EVI1 BINDING CAUSED THE RE-DISTRIBUTION OF ENDOGENOUS RUNX1 WITHIN THE GENOME AND INTERFERED WITH BOTH RUNX1 AND EVI1 REGULATED GENE EXPRESSION PROGRAMS. IN SUMMARY, RUNX1-EVI1 EXPRESSION ALONE LEADS TO EXTENSIVE EPIGENETIC REPROGRAMMING WHICH IS INCOMPATIBLE WITH HEALTHY BLOOD PRODUCTION. 2021 4 5911 22 TARGETED NEXT-GENERATION SEQUENCING IN MYELODYSPLASTIC SYNDROME AND CHRONIC MYELOMONOCYTIC LEUKEMIA AIDS DIAGNOSIS IN CHALLENGING CASES AND IDENTIFIES FREQUENT SPLICEOSOME MUTATIONS IN TRANSFORMED ACUTE MYELOID LEUKEMIA. OBJECTIVES: OPTIMAL INTEGRATION OF NEXT-GENERATION SEQUENCING (NGS) INTO CLINICAL PRACTICE IN HEMATOLOGIC MALIGNANCIES REMAINS UNCLEAR. WE EVALUATE THE UTILITY OF NGS IN MYELOID MALIGNANCIES. METHODS: A 42-GENE PANEL WAS USED TO SEQUENCE 109 CASES OF MYELODYSPLASTIC SYNDROME (MDS, N = 38), CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML, N = 14), MYELOPROLIFERATIVE NEOPLASM (MPN, N = 24), AND MDS AND/OR MPN TRANSFORMED TO ACUTE MYELOID LEUKEMIA (AML, N = 33). RESULTS: AT LEAST ONE PATHOGENIC MUTATION WAS IDENTIFIED IN 74% OF CASES OF MDS, 100% OF CMMLS, AND 96% OF MPNS. IN CONTRAST, ONLY 47% OF CASES OF MDS (18/38) AND 7% (1/14) OF CMMLS EXHIBITED ABNORMAL CYTOGENETICS. IN DIAGNOSTICALLY DIFFICULT CASES OF MDS OR CMML WITH NORMAL CYTOGENETICS, NGS IDENTIFIED A PATHOGENIC MUTATION AND WAS CRITICAL IN ESTABLISHING THE CORRECT DIAGNOSIS. SPLICEOSOMAL GENES AND EPIGENETIC MODIFIERS WERE FREQUENTLY MUTATED. SPLICEOSOME MUTATIONS WERE ALSO FREQUENTLY DETECTED IN AML ARISING FROM MDS, CMML, OR MPN (39%) COMPARED WITH THE REPORTED RATE IN DE NOVO AML (7%-14%). CONCLUSIONS: IN DIFFICULT CASES OF MDS OR MPN, NGS FACILITATES DIAGNOSIS BY DETECTION OF GENE MUTATIONS TO CONFIRM CLONALITY, AND AMLS EVOLVING FROM MDS OR MPN CARRY FREQUENT MUTATIONS IN SPLICEOSOMAL GENES. 2016 5 4553 20 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 6 1184 17 COOPERATIVE EPIGENETIC REMODELING BY TET2 LOSS AND NRAS MUTATION DRIVES MYELOID TRANSFORMATION AND MEK INHIBITOR SENSITIVITY. MUTATIONS IN EPIGENETIC MODIFIERS AND SIGNALING FACTORS OFTEN CO-OCCUR IN MYELOID MALIGNANCIES, INCLUDING TET2 AND NRAS MUTATIONS. CONCURRENT TET2 LOSS AND NRAS(G12D) EXPRESSION IN HEMATOPOIETIC CELLS INDUCED MYELOID TRANSFORMATION, WITH A FULLY PENETRANT, LETHAL CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), WHICH WAS SERIALLY TRANSPLANTABLE. TET2 LOSS AND NRAS MUTATION COOPERATIVELY LED TO DECREASE IN NEGATIVE REGULATORS OF MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) ACTIVATION, INCLUDING SPRY2, THEREBY CAUSING SYNERGISTIC ACTIVATION OF MAPK SIGNALING BY EPIGENETIC SILENCING. TET2/NRAS DOUBLE-MUTANT LEUKEMIA SHOWED PREFERENTIAL SENSITIVITY TO MAPK KINASE (MEK) INHIBITION IN BOTH MOUSE MODEL AND PATIENT SAMPLES. THESE DATA PROVIDE INSIGHTS INTO HOW EPIGENETIC AND SIGNALING MUTATIONS COOPERATE IN MYELOID TRANSFORMATION AND PROVIDE A RATIONALE FOR MECHANISM-BASED THERAPY IN CMML PATIENTS WITH THESE HIGH-RISK GENETIC LESIONS. 2018 7 4005 19 LOSS OF THE TUMOR SUPPRESSOR BAP1 CAUSES MYELOID TRANSFORMATION. DE-UBIQUITINATING ENZYME BAP1 IS MUTATED IN A HEREDITARY CANCER SYNDROME WITH INCREASED RISK OF MESOTHELIOMA AND UVEAL MELANOMA. SOMATIC BAP1 MUTATIONS OCCUR IN VARIOUS MALIGNANCIES. WE SHOW THAT MOUSE BAP1 GENE DELETION IS LETHAL DURING EMBRYOGENESIS, BUT SYSTEMIC OR HEMATOPOIETIC-RESTRICTED DELETION IN ADULTS RECAPITULATES FEATURES OF HUMAN MYELODYSPLASTIC SYNDROME (MDS). KNOCKIN MICE EXPRESSING BAP1 WITH A 3XFLAG TAG REVEALED THAT BAP1 INTERACTS WITH HOST CELL FACTOR-1 (HCF-1), O-LINKED N-ACETYLGLUCOSAMINE TRANSFERASE (OGT), AND THE POLYCOMB GROUP PROTEINS ASXL1 AND ASXL2 IN VIVO. OGT AND HCF-1 LEVELS WERE DECREASED BY BAP1 DELETION, INDICATING A CRITICAL ROLE FOR BAP1 IN STABILIZING THESE EPIGENETIC REGULATORS. HUMAN ASXL1 IS MUTATED FREQUENTLY IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) SO AN ASXL/BAP1 COMPLEX MAY SUPPRESS CMML. A BAP1 CATALYTIC MUTATION FOUND IN A MDS PATIENT IMPLIES THAT BAP1 LOSS OF FUNCTION HAS SIMILAR CONSEQUENCES IN MICE AND HUMANS. 2012 8 1070 16 CLONAL ARCHITECTURE OF CHRONIC MYELOMONOCYTIC LEUKEMIAS. GENOMIC STUDIES IN CHRONIC MYELOID MALIGNANCIES, INCLUDING MYELOPROLIFERATIVE NEOPLASMS (MPN), MYELODYSPLASTIC SYNDROMES (MDS), AND MPN/MDS, HAVE IDENTIFIED COMMON MUTATIONS IN GENES ENCODING SIGNALING, EPIGENETIC, TRANSCRIPTION, AND SPLICING FACTORS. IN THE PRESENT STUDY, WE INTERROGATED THE CLONAL ARCHITECTURE BY MUTATION-SPECIFIC DISCRIMINATION ANALYSIS OF SINGLE-CELL-DERIVED COLONIES IN 28 PATIENTS WITH CHRONIC MYELOMONOCYTIC LEUKEMIAS (CMML), THE MOST FREQUENT MPN/MDS. THIS ANALYSIS REVEALS A LINEAR ACQUISITION OF THE STUDIED MUTATIONS WITH LIMITED BRANCHING THROUGH LOSS OF HETEROZYGOSITY. SERIAL ANALYSIS OF UNTREATED AND TREATED SAMPLES DEMONSTRATES A DYNAMIC ARCHITECTURE ON WHICH MOST CURRENT THERAPEUTIC APPROACHES HAVE LIMITED EFFECTS. THE MAIN DISEASE CHARACTERISTICS ARE EARLY CLONAL DOMINANCE, ARISING AT THE CD34(+)/CD38(-) STAGE OF HEMATOPOIESIS, AND GRANULOMONOCYTIC DIFFERENTIATION SKEWING OF MULTIPOTENT AND COMMON MYELOID PROGENITORS. COMPARISON OF CLONAL EXPANSIONS OF TET2 MUTATIONS IN MDS, MPN, AND CMML, TOGETHER WITH FUNCTIONAL INVALIDATION OF TET2 IN SORTED PROGENITORS, SUGGESTS A CAUSATIVE LINK BETWEEN EARLY CLONAL DOMINANCE AND SKEWED GRANULOMONOCYTIC DIFFERENTIATION. ALTOGETHER, EARLY CLONAL DOMINANCE MAY DISTINGUISH CMML FROM OTHER CHRONIC MYELOID NEOPLASMS WITH SIMILAR GENE MUTATIONS. 2013 9 3009 23 GENETICS AND EPIGENETICS IN NEOPLASMS WITH PLASMACYTOID DENDRITIC CELLS. PLASMACYTOID DENDRITIC CELLS (PDC) ARE TYPE I INTERFERON (IFN)-PRODUCING CELLS THAT PLAY A KEY ROLE IN IMMUNE RESPONSES. TWO MAJOR TYPES OF NEOPLASTIC COUNTERPARTS FOR PDC ARE NOW DISCRIMINATED: BLASTIC PDC NEOPLASM (BPDCN) AND MATURE PDC PROLIFERATION (MPDCP), ASSOCIATED WITH MYELOID NEOPLASM. TWO TYPES OF MPDCP ARE NOW BETTER DESCRIBED: CHRONIC MYELOMONOCYTIC LEUKEMIA WITH PDC EXPANSION (PDC-CMML) AND ACUTE MYELOID LEUKEMIA WITH PDC EXPANSION (PDC-AML). DIFFERENTIAL DIAGNOSIS BETWEEN PDC-AML AND BPDCN IS PARTICULARLY CHALLENGING, AND GENOMIC FEATURES CAN HELP FOR DIAGNOSIS. HERE, WE SYSTEMATICALLY REVIEW THE CYTOGENETIC, MOLECULAR, AND TRANSCRIPTIONAL CHARACTERISTICS OF BPDCN AND PDC-AML. BPDCN ARE CHARACTERIZED BY FREQUENT COMPLEX KARYOTYPES WITH RECURRENT MYB/MYC REARRANGEMENTS AS WELL AS RECURRENT DELETIONS INVOLVING ETV6, IKZF1, RB1, AND TP53 LOCI. EPIGENETIC AND SPLICING PATHWAYS ARE ALSO PARTICULARLY MUTATED, WHILE ORIGINAL PROCESSES ARE DYSREGULATED, SUCH AS NF-KB, TCF4, BCL2, AND IFN PATHWAYS; NEUTROPHIL-SPECIFIC RECEPTORS; AND CHOLINERGIC SIGNALING. IN CONTRAST, CYTOGENETIC ABNORMALITIES ARE LIMITED IN PDC-AML AND ARE QUITE SIMILAR TO OTHER AML. INTERESTINGLY, RUNX1 IS THE MOST FREQUENTLY MUTATED GENE (70% OF CASES). THESE TYPICAL GENOMIC FEATURES ARE OF POTENTIAL INTEREST FOR DIAGNOSIS, AND ALSO FROM A PROGNOSTIC OR THERAPEUTIC PERSPECTIVE. 2022 10 569 20 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 11 2996 23 GENETIC PROFILE AND MICROSATELLITE INSTABILITY IN A CASE OF SECONDARY ESOPHAGEAL SQUAMOUS CELL CARCINOMA 12 YEARS AFTER ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION FOR APLASTIC ANEMIA. WE REPORT ON A 16-YEAR-OLD JAPANESE BOY IN WHOM AN ESOPHAGEAL SQUAMOUS CELL CARCINOMA (ESCC) DEVELOPED 12 YEARS AFTER ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION WAS PERFORMED FOR APLASTIC ANEMIA. A HIGH FREQUENCY OF MICROSATELLITE INSTABILITY WAS DETECTED IN SAMPLES OF ESCC. MOREOVER, THE DETECTION OF PATHOGENIC VARIANTS, INCLUDING SINGLE NUCLEOTIDE SUBSTITUTION OF TP53 (C.346C>T) AND BRCA2 (C.6952C>T) AND SPLICING OF KDM6A (C.1194+2T>G), SUGGEST THAT THE DEVELOPMENT OF ESCC IN THE PATIENT WAS TRIGGERED BY IMPAIRMENT OF CHECKPOINT AND REPAIR FOR DNA DAMAGE AND EPIGENETIC MODIFICATION THROUGH ACCUMULATION OF GENE MUTATIONS INDUCED BY CHRONIC GRAFT-VERSUS-HOST DISEASE AND PROLONGED ADMINISTRATION OF TACROLIMUS. 2020 12 1266 19 CYTOGENETIC AND MOLECULAR ABNORMALITIES IN CHRONIC MYELOMONOCYTIC LEUKEMIA. CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) IS A CLONAL STEM CELL DISORDER ASSOCIATED WITH PERIPHERAL BLOOD MONOCYTOSIS AND AN INHERENT TENDENCY TO TRANSFORM TO ACUTE MYELOID LEUKEMIA. CMML HAS OVERLAPPING FEATURES OF MYELODYSPLASTIC SYNDROMES AND MYELOPROLIFERATIVE NEOPLASMS. CLONAL CYTOGENETIC CHANGES ARE SEEN IN ~30%, WHEREAS GENE MUTATIONS ARE SEEN IN >90% OF PATIENTS. COMMON CYTOGENETIC ABNORMALITIES INCLUDE; TRISOMY 8, -Y, -7/DEL(7Q), TRISOMY 21 AND DEL(20Q), WITH THE MAYO-FRENCH RISK STRATIFICATION EFFECTIVELY RISK STRATIFYING PATIENTS BASED ON CYTOGENETIC ABNORMALITIES. GENE MUTATIONS FREQUENTLY INVOLVE EPIGENETIC REGULATORS (TET2 ~60%), MODULATORS OF CHROMATIN (ASXL1 ~40%), SPLICEOSOME COMPONENTS (SRSF2 ~50%), TRANSCRIPTION FACTORS (RUNX1 ~15%) AND SIGNAL PATHWAYS (RAS ~30%, CBL ~15%). OF THESE, THUS FAR, ONLY NONSENSE AND FRAMESHIFT ASXL1 MUTATIONS HAVE BEEN SHOWN TO NEGATIVELY IMPACT OVERALL SURVIVAL. THIS HAS RESULTED IN THE DEVELOPMENT OF CONTEMPORARY, MOLECULARLY INTEGRATED (INCLUSIVE OF ASXL1 MUTATIONS) CMML PROGNOSTIC MODELS, INCLUDING MOLECULAR MAYO MODEL AND THE GROUPE FRANCAIS DES MYELODYSPLASIES MODEL. BETTER UNDERSTANDING OF THE PREVALENT GENETIC AND EPIGENETIC DYSREGULATION HAS RESULTED IN EMERGING TARGETED TREATMENT OPTIONS FOR SOME PATIENTS. THE DEVELOPMENT OF AN INTEGRATED (CYTOGENETIC AND MOLECULAR) PROGNOSTIC MODEL ALONG WITH CMML-SPECIFIC RESPONSE ASSESSMENT CRITERIA ARE MUCH NEEDED FUTURE GOALS. 2016 13 4557 14 MUTATIONS IN ASXL1 ARE ASSOCIATED WITH POOR PROGNOSIS ACROSS THE SPECTRUM OF MALIGNANT MYELOID DISEASES. THE ASXL1 GENE IS ONE OF THE MOST FREQUENTLY MUTATED GENES IN MALIGNANT MYELOID DISEASES. THE ASXL1 PROTEIN BELONGS TO PROTEIN COMPLEXES INVOLVED IN THE EPIGENETIC REGULATION OF GENE EXPRESSION. ASXL1 MUTATIONS ARE FOUND IN MYELOPROLIFERATIVE NEOPLASMS (MPN), MYELODYSPLASTIC SYNDROMES (MDS), CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AND ACUTE MYELOID LEUKEMIA (AML). THEY ARE GENERALLY ASSOCIATED WITH SIGNS OF AGGRESSIVENESS AND POOR CLINICAL OUTCOME. BECAUSE OF THIS, A SYSTEMATIC DETERMINATION OF ASXL1 MUTATIONAL STATUS IN MYELOID MALIGNANCIES SHOULD HELP IN PROGNOSIS ASSESSMENT. 2012 14 5789 22 SRSF2(P95H/+) CO-OPERATES WITH LOSS OF TET2 TO PROMOTE MYELOID BIAS AND INITIATE A CHRONIC MYELOMONOCYTIC LEUKEMIA-LIKE DISEASE IN MICE. RECURRENT MUTATIONS IN RNA SPLICING PROTEINS AND EPIGENETIC REGULATORS CONTRIBUTE TO THE DEVELOPMENT OF MYELODYSPLASTIC SYNDROME (MDS) AND RELATED MYELOID NEOPLASMS. IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), SRSF2 MUTATIONS OCCUR IN ~50% OF PATIENTS AND TET2 MUTATIONS IN ~60%. CLONAL ANALYSIS INDICATES THAT EITHER MUTATION CAN ARISE AS THE FOUNDER LESION. BASED ON HUMAN CANCER GENETICS WE CROSSED AN INDUCIBLE SRSF2(P95H/+) MUTANT MODEL WITH TET2(FL/FL) MICE TO MUTATE BOTH CONCOMITANTLY IN HEMATOPOIETIC STEM CELLS. AT 20-24 WEEKS POST MUTATION INDUCTION, WE OBSERVED SUBTLE DIFFERENCES IN THE SRSF2/TET2 MUTANTS COMPARED TO EITHER SINGLE MUTANT. UNDER CONDITIONS OF NATIVE HEMATOPOIESIS WITH AGING, WE SEE A DISTINCT MYELOID BIAS AND MONOCYTOSIS IN THE SRSF2/TET2 MUTANTS. A SUBSET OF THE COMPOUND SRSF2/TET2 MUTANTS DISPLAY AN INCREASED GRANULOCYTIC AND DISTINCTIVE MONOCYTIC PROLIFERATION (MYELOMONOCYTIC HYPERPLASIA), WITH INCREASED IMMATURE PROMONOCYTES AND MONOBLASTS AND BINUCLEATE PROMONOCYTES. EXOME ANALYSIS OF PROGRESSED DISEASE DEMONSTRATED MUTATIONS IN GENES AND PATHWAYS SIMILAR TO THOSE REPORTED IN HUMAN CMML. UPON TRANSPLANTATION, RECIPIENTS DEVELOPED LEUKOCYTOSIS, MONOCYTOSIS, AND SPLENOMEGALY. WE REPRODUCE SRSF2/TET2 CO-OPERATIVITY IN VIVO, YIELDING A DISEASE WITH CORE CHARACTERISTICS OF CMML, UNLIKE SINGLE SRSF2 OR TET2 MUTATION. THIS MODEL REPRESENTS A SIGNIFICANT STEP TOWARD BUILDING HIGH FIDELITY AND GENETICALLY TRACTABLE MODELS OF CMML. 2022 15 1311 23 DEFINITIONS, BIOLOGY, AND CURRENT THERAPEUTIC LANDSCAPE OF MYELODYSPLASTIC/MYELOPROLIFERATIVE NEOPLASMS. MYELODYSPLASTIC/MYELOPROLIFERATIVE NEOPLASMS (MDS/MPN) ARE HEMATOLOGICAL DISORDERS CHARACTERIZED BY BOTH PROLIFERATIVE AND DYSPLASTIC FEATURES. ACCORDING TO THE 2022 INTERNATIONAL CONSENSUS CLASSIFICATION (ICC), MDS/MPN CONSISTS OF CLONAL MONOCYTOSIS OF UNDETERMINED SIGNIFICANCE (CMUS), CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), ATYPICAL CHRONIC MYELOID LEUKEMIA (ACML), MDS/MPN WITH SF3B1 MUTATION (MDS/MPN-T-SF3B1), MDS/MPN WITH RING SIDEROBLASTS AND THROMBOCYTOSIS NOT OTHERWISE SPECIFIED (MDS/MPN-RS-T-NOS), AND MDS/MPN-NOS. THESE DISORDERS EXHIBIT A DIVERSE RANGE OF GENETIC ALTERATIONS INVOLVING VARIOUS TRANSCRIPTION FACTORS (E.G., RUNX1), SIGNALING MOLECULES (E.G., NRAS, JAK2), SPLICING FACTORS (E.G., SF3B, SRSF2), AND EPIGENETIC REGULATORS (E.G., TET2, ASXL1, DNMT3A), AS WELL AS SPECIFIC CYTOGENETIC ABNORMALITIES (E.G., 8 TRISOMIES, 7 DELETIONS/MONOSOMIES). CLINICAL STUDIES EXPLORING THERAPEUTIC OPTIONS FOR HIGHER-RISK MDS/MPN OVERLAP SYNDROMES MOSTLY INVOLVE HYPOMETHYLATING AGENTS, BUT OTHER TREATMENTS SUCH AS LENALIDOMIDE AND TARGETED AGENTS SUCH AS JAK INHIBITORS AND INHIBITORS TARGETING PARP, HISTONE DEACETYLASES, AND THE RAS PATHWAY ARE UNDER INVESTIGATION. WHILE THESE TREATMENT MODALITIES CAN PROVIDE PARTIAL DISEASE CONTROL, ALLOGENEIC BONE MARROW TRANSPLANTATION (ALLO-BMT) IS THE ONLY POTENTIALLY CURATIVE OPTION FOR PATIENTS. IMPORTANT PROGNOSTIC FACTORS CORRELATING WITH OUTCOMES AFTER ALLO-BMT INCLUDE COMORBIDITIES, SPLENOMEGALY, KARYOTYPE ALTERATIONS, AND THE BONE MARROW BLASTS PERCENTAGE AT THE TIME OF TRANSPLANTATION. FUTURE RESEARCH IS IMPERATIVE TO OPTIMIZING THERAPEUTIC STRATEGIES AND ENHANCING PATIENT OUTCOMES IN MDS/MPN NEOPLASMS. IN THIS REVIEW, WE SUMMARIZE MDS/MPN DIAGNOSTIC CRITERIA, BIOLOGY, AND CURRENT AND FUTURE TREATMENT OPTIONS, INCLUDING BONE MARROW TRANSPLANTATION. 2023 16 2888 33 GAIN-OF-FUNCTION MUTATION OF GATA-2 IN ACUTE MYELOID TRANSFORMATION OF CHRONIC MYELOID LEUKEMIA. ACQUISITION OF ADDITIONAL GENETIC AND/OR EPIGENETIC ABNORMALITIES OTHER THAN THE BCR/ABL FUSION GENE IS BELIEVED TO CAUSE DISEASE PROGRESSION IN CHRONIC MYELOID LEUKEMIA (CML) FROM CHRONIC PHASE TO BLAST CRISIS (BC). TO GAIN INSIGHTS INTO THE UNDERLYING MECHANISMS OF PROGRESSION TO BC, WE SCREENED DNA SAMPLES FROM CML PATIENTS DURING BLAST TRANSFORMATION FOR MUTATIONS IN A NUMBER OF TRANSCRIPTION FACTOR GENES THAT ARE CRITICAL FOR MYELOID-LYMPHOID DEVELOPMENT. IN 85 CASES OF CML BLAST TRANSFORMATION, WE IDENTIFIED TWO NEW MUTATIONS IN THE CODING REGION OF GATA-2, A NEGATIVE REGULATOR OF HEMATOPOIETIC STEM/PROGENITOR CELL DIFFERENTIATION. A L359V SUBSTITUTION WITHIN ZINC FINGER DOMAIN (ZF) 2 OF GATA-2 WAS FOUND IN EIGHT CASES WITH MYELOMONOBLASTIC FEATURES, WHEREAS AN IN-FRAME DELETION OF 6 AA (DELTA341-346) SPANNING THE C-TERMINAL BORDER OF ZF1 WAS DETECTED IN ONE PATIENT AT MYELOID BC WITH EOSINOPHILIA. FURTHER STUDIES INDICATED THAT L359V NOT ONLY INCREASED TRANSACTIVATION ACTIVITY OF GATA-2 BUT ALSO ENHANCED ITS INHIBITORY EFFECTS ON THE ACTIVITY OF PU.1, A MAJOR REGULATOR OF MYELOPOIESIS. CONSISTENT WITH THE MYELOMONOBLASTIC FEATURES OF CML TRANSFORMATION WITH THE GATA-2 L359V MUTANT, TRANSDUCTION OF THE GATA-2 L359V MUTANT INTO HL-60 CELLS OR BCR/ABL-HARBORING MURINE CELLS DISTURBED MYELOMONOCYTIC DIFFERENTIATION/PROLIFERATION IN VITRO AND IN VIVO, RESPECTIVELY. THESE DATA STRONGLY SUGGEST THAT GATA-2 MUTATIONS MAY PLAY A ROLE IN ACUTE MYELOID TRANSFORMATION IN A SUBSET OF CML PATIENTS. 2008 17 5934 25 TARGETING FEATURES OF CURAXIN CBL0137 ON HEMATOLOGICAL MALIGNANCIES IN VITRO AND IN VIVO. THE ANTICANCER ACTIVITY OF CURAXIN CBL0137, A DNA-BINDING SMALL MOLECULE WITH CHROMATIN REMODULATING EFFECT, HAS BEEN DEMONSTRATED IN DIFFERENT CANCERS. HEREIN, A COMPARATIVE EVALUATION OF CBL0137 ACTIVITY WAS PERFORMED IN RESPECT TO ACUTE MYELOID LEUKEMIA (AML), ACUTE LYMPHOBLASTIC LEUKEMIA (ALL), CHRONIC MYELOID LEUKEMIA AND MULTIPLE MYELOMA (MM) CULTURED IN VITRO. MTT ASSAY SHOWED AML AND MM HIGHER SENSITIVITY TO CBL0137'S CYTOSTATIC EFFECT COMPARATIVELY TO OTHER HEMATOLOGICAL MALIGNANCY CELLS. FLOW CYTOMETRY CELL CYCLE ANALYSIS REVEALED AN INCREASE IN SUBG1 AND G2/M POPULATIONS AFTER CBL0137 CELL TREATMENT, BUT THE PREVALENT TYPE OF ARREST VARIED. APOPTOSIS ACTIVATION BY CBL0137 MEASURED BY ANNEXIN-V/PI DUAL STAINING WAS MORE ACTIVE IN AML AND MM CELLS. RT2 PCR ARRAY SHOWED THAT CHANGES CAUSED BY CBL0137 IN SIGNALING PATHWAYS INVOLVED IN CANCER PATHOGENESIS WERE MORE INTENSIVE IN AML AND MM CELLS. ON THE MURINE MODEL OF AML WEHI-3, CBL0137 SHOWED SIGNIFICANT ANTICANCER EFFECTS IN VIVO, WHICH WERE EVALUATED BY CORRESPONDING CHANGES IN SPLEEN AND LIVER. THUS, MORE PRONOUNCED ANTICANCER EFFECTS OF CBL0137 IN VITRO WERE OBSERVED IN RESPECT TO AML AND MM. EXPERIMENTS IN VIVO ALSO INDICATED THE PERSPECTIVE OF CBL0137 USE FOR AML TREATMENT. THIS IN ACCORDANCE WITH THE FRONTLINE TREATMENT APPROACH IN AML USING EPIGENETIC DRUGS. 2023 18 1083 19 CNL AND ACML SHOULD BE CONSIDERED AS A SINGLE ENTITY BASED ON MOLECULAR PROFILES AND OUTCOMES. CHRONIC NEUTROPHILIC LEUKEMIA (CNL) AND ATYPICAL CHRONIC MYELOID LEUKEMIA (ACML) ARE RARE MYELOID DISORDERS THAT ARE CHALLENGING WITH REGARD TO DIAGNOSIS AND CLINICAL MANAGEMENT. TO STUDY THE SIMILARITIES AND DIFFERENCES BETWEEN THESE DISORDERS, WE UNDERTOOK A MULTICENTER INTERNATIONAL STUDY OF ONE OF THE LARGEST CASE SERIES (CNL, N = 24; ACML, N = 37 CASES, RESPECTIVELY), FOCUSING ON THE CLINICAL AND MUTATIONAL PROFILES (N = 53 WITH MOLECULAR DATA) OF THESE DISEASES. WE FOUND NO DIFFERENCES IN CLINICAL PRESENTATIONS OR OUTCOMES OF BOTH ENTITIES. AS PREVIOUSLY DESCRIBED, BOTH CNL AND ACML SHARE A COMPLEX MUTATIONAL PROFILE WITH MUTATIONS IN GENES INVOLVED IN EPIGENETIC REGULATION, SPLICING, AND SIGNALING PATHWAYS. APART FROM CSF3R, ONLY EZH2 AND TET2 WERE DIFFERENTIALLY MUTATED BETWEEN THEM. THE MOLECULAR PROFILES SUPPORT THE NOTION OF CNL AND ACML BEING A CONTINUUM OF THE SAME DISEASE THAT MAY FIT BEST WITHIN THE MYELODYSPLASTIC/MYELOPROLIFERATIVE NEOPLASMS. WE IDENTIFIED 4 HIGH-RISK MUTATED GENES, SPECIFICALLY CEBPA (BETA = 2.26, HAZARD RATIO [HR] = 9.54, P = .003), EZH2 (BETA = 1.12, HR = 3.062, P = .009), NRAS (BETA = 1.29, HR = 3.63, P = .048), AND U2AF1 (BETA = 1.75, HR = 5.74, P = .013) USING MULTIVARIATE ANALYSIS. OUR FINDINGS UNDERSCORE THE RELEVANCE OF MOLECULAR-RISK CLASSIFICATION IN CNL/ACML AS WELL AS THE IMPORTANCE OF CSF3R MUTATIONS IN THESE DISEASES. 2023 19 4549 24 MUTATION ANALYSIS OF THERAPY-RELATED MYELOID NEOPLASMS. WE ANALYZED THE GENETIC MUTATION STATUS OF 13 PATIENTS WITH THERAPY-RELATED MYELOID NEOPLASMS (T-MN). CONSISTENT WITH PREVIOUS REPORTS, T-MN CELLS PREFERENTIALLY ACQUIRED MUTATIONS IN TP53 AND EPIGENETIC MODIFYING GENES, INSTEAD OF MUTATIONS IN TYROSINE KINASE AND SPLICEOSOME GENES. FURTHERMORE, WE COMPARED THE MUTATION STATUS OF THREE T-MN CELLS WITH EACH OF THE INITIAL LYMPHOID MALIGNANT CELLS, AND IDENTIFIED COMMON MUTATIONS AMONG T-MN AND THE INITIAL MALIGNANT CELLS IN TWO PATIENTS. IN A PATIENT WHO DEVELOPED CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AFTER FOLLICULAR LYMPHOMA (FL), TET2 MUTATION WAS IDENTIFIED IN BOTH CMML AND FL CELLS. NOTABLY, THE TET2 MUTATION WAS ALSO IDENTIFIED IN PERIPHERAL BLOOD CELLS IN THE DISEASE-FREE PERIOD WITH THE SAME ALLELIC FREQUENCY AS CMML AND FL CELLS, BUT NOT IN A GERM-LINE CONTROL, INDICATING THAT THE TET2 MUTATION OCCURRED SOMATICALLY IN THE INITIATING CLONE FOR BOTH MALIGNANT CELLS. ON THE OTHER HAND, A GERM-LINE MYB MUTATION WAS IDENTIFIED IN A PATIENT WHO DEVELOPED MYELODYSPLASTIC SYNDROMES (MDS) AFTER FL. THESE RESULTS SUGGEST THAT GERM-LINE DEPOSITION AND CLONAL HEMATOPOIESIS ARE CLOSELY ASSOCIATED WITH T-MN SUSCEPTIBILITY; HOWEVER, FURTHER ANALYSIS IS NECESSARY TO CLARIFY THE MECHANISM REQUIRED TO PROVIDE THE INITIATING CLONE WITH LINEAGE COMMITMENT AND CLONAL EXPANSION. 2018 20 4748 26 NOVEL MUTATIONS AND THEIR FUNCTIONAL AND CLINICAL RELEVANCE IN MYELOPROLIFERATIVE NEOPLASMS: JAK2, MPL, TET2, ASXL1, CBL, IDH AND IKZF1. MYELOPROLIFERATIVE NEOPLASMS (MPNS) ORIGINATE FROM GENETICALLY TRANSFORMED HEMATOPOIETIC STEM CELLS THAT RETAIN THE CAPACITY FOR MULTILINEAGE DIFFERENTIATION AND EFFECTIVE MYELOPOIESIS. BEGINNING IN EARLY 2005, A NUMBER OF NOVEL MUTATIONS INVOLVING JANUS KINASE 2 (JAK2), MYELOPROLIFERATIVE LEUKEMIA VIRUS (MPL), TET ONCOGENE FAMILY MEMBER 2 (TET2), ADDITIONAL SEX COMBS-LIKE 1 (ASXL1), CASITAS B-LINEAGE LYMPHOMA PROTO-ONCOGENE (CBL), ISOCITRATE DEHYDROGENASE (IDH) AND IKAROS FAMILY ZINC FINGER 1 (IKZF1) HAVE BEEN DESCRIBED IN BCR-ABL1-NEGATIVE MPNS. HOWEVER, NONE OF THESE MUTATIONS WERE MPN SPECIFIC, DISPLAYED MUTUAL EXCLUSIVITY OR COULD BE TRACED BACK TO A COMMON ANCESTRAL CLONE. JAK2 AND MPL MUTATIONS APPEAR TO EXERT A PHENOTYPE-MODIFYING EFFECT AND ARE DISTINCTLY ASSOCIATED WITH POLYCYTHEMIA VERA, ESSENTIAL THROMBOCYTHEMIA AND PRIMARY MYELOFIBROSIS; THE CORRESPONDING MUTATIONAL FREQUENCIES ARE APPROXIMATELY 99, 55 AND 65% FOR JAK2 AND 0, 3 AND 10% FOR MPL MUTATIONS. THE INCIDENCE OF TET2, ASXL1, CBL, IDH OR IKZF1 MUTATIONS IN THESE DISORDERS RANGES FROM 0 TO 17%; THESE LATTER MUTATIONS ARE MORE COMMON IN CHRONIC (TET2, ASXL1, CBL) OR JUVENILE (CBL) MYELOMONOCYTIC LEUKEMIAS, MASTOCYTOSIS (TET2), MYELODYSPLASTIC SYNDROMES (TET2, ASXL1) AND SECONDARY ACUTE MYELOID LEUKEMIA, INCLUDING BLAST-PHASE MPN (IDH, ASXL1, IKZF1). THE FUNCTIONAL CONSEQUENCES OF MPN-ASSOCIATED MUTATIONS INCLUDE UNREGULATED JAK-STAT (JANUS KINASE/SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION) SIGNALING, EPIGENETIC MODULATION OF TRANSCRIPTION AND ABNORMAL ACCUMULATION OF ONCOPROTEINS. HOWEVER, IT IS NOT CLEAR AS TO WHETHER AND HOW THESE ABNORMALITIES CONTRIBUTE TO DISEASE INITIATION, CLONAL EVOLUTION OR BLASTIC TRANSFORMATION. 2010