1 2996 79 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 2 1959 21 EPIGENETIC AGING AND HEMATOPOIETIC CELL TRANSPLANTATION IN PATIENTS WITH SEVERE APLASTIC ANEMIA. CELLULAR AGING IN HEMATOPOIETIC CELL TRANSPLANTATION (HCT) IS IMPORTANT IN THE CONTEXT OF IMMUNE RECONSTITUTION AND AGE-RELATED COMPLICATIONS. RECENTLY, SEVERAL DNA-METHYLATION (DNAM)-BASED BIOMARKERS OF AGING KNOWN AS "EPIGENETIC CLOCKS" HAVE BEEN INTRODUCED AS NOVEL TOOLS TO PREDICT CELLULAR AGE. HERE, WE USED COX PROPORTIONAL HAZARDS MODELS TO ASSESS THE POSSIBLE ASSOCIATIONS OF DONOR PRE-HCT DNAM AGE, AND ITS POST-HCT CHANGES, USING THE RECENTLY PUBLISHED LIFESPAN-ASSOCIATED EPIGENETIC CLOCK KNOWN AS "DNAM-GRIMAGE," WITH OUTCOMES AMONG PATIENTS WITH SEVERE APLASTIC ANEMIA (SAA). THE STUDY INCLUDED 732 SAA PATIENTS FROM THE TRANSPLANT OUTCOMES IN APLASTIC ANEMIA PROJECT, WHO UNDERWENT UNRELATED DONOR HCT AND FOR WHOM A DONOR PRE-HCT BLOOD DNA SAMPLE WAS AVAILABLE; 41 ALSO HAD A POST-HCT SAMPLE COLLECTED AT DAY 100. IN MULTIVARIABLE ANALYSES, WE FOUND SIMILAR ASSOCIATIONS FOR DONOR CHRONOLOGICAL AGE AND PRE-HCT DNAM-GRIMAGE WITH POST-HCT SURVIVAL (HAZARD RATIO [HR] PER DECADE = 1.13; 95% CONFIDENCE INTERVAL [CI], 0.99-1.28; P = .07 AND HR = 1.14; 95% CI, 0.99-1.28; P = .06, RESPECTIVELY). IN DONORS WITH 10+ YEARS OF GRIMAGE ACCELERATION (IE, DEVIATION FROM EXPECTED DNAM AGE FOR CHRONOLOGICAL AGE), ELEVATED RISKS OF CHRONIC GRAFT VERSUS HOST DISEASE (HR = 2.4; 95% CI, 1.21-4.65; P = .01) AND POSSIBLY POST-HCT MORTALITY (HR = 1.79; 95% CI, 0.96-3.33; P = .07) WERE OBSERVED. IN THE SUBSET WITH POST-HCT SAMPLES, WE OBSERVED A SIGNIFICANT INCREASE IN DNAM-GRIMAGE IN THE FIRST 100 DAYS AFTER HCT (MEDIAN CHANGE 12.5 YEARS, RANGE 1.4 TO 26.4). HIGHER DNAM-GRIMAGE AFTER HCT WAS ASSOCIATED WITH INFERIOR SURVIVAL (HR PER YEAR = 1.11; 95% CI, 1.02-1.21; P = .01), PREDOMINANTLY WITHIN THE FIRST YEAR AFTER HCT. THIS STUDY HIGHLIGHTS THE POSSIBLE ROLE CELLULAR AGING MAY PLAY IN HCT OUTCOMES. 2021 3 4181 16 MESENCHYMAL STEM CELLS IN IMMUNE-MEDIATED BONE MARROW FAILURE SYNDROMES. IMMUNE-MEDIATED BONE MARROW FAILURE SYNDROMES (BMFS) ARE CHARACTERIZED BY INEFFECTIVE MARROW HAEMOPOIESIS AND SUBSEQUENT PERIPHERAL CYTOPENIAS. INEFFECTIVE HAEMOPOIESIS IS THE RESULT OF A COMPLEX MARROW DEREGULATION INCLUDING GENETIC, EPIGENETIC, AND IMMUNE-MEDIATED ALTERATIONS IN HAEMOPOIETIC STEM/PROGENITOR CELLS, AS WELL AS ABNORMAL HAEMOPOIETIC-TO-STROMAL CELL INTERACTIONS, WITH ABNORMAL RELEASE OF HAEMOPOIETIC GROWTH FACTORS, CHEMOKINES, AND INHIBITORS. MESENCHYMAL STEM/STROMAL CELLS (MSCS) AND THEIR PROGENY (I.E., OSTEOBLASTS, ADIPOCYTES, AND RETICULAR CELLS) ARE CONSIDERED AS KEY CELLULAR COMPONENTS OF THE BONE MARROW HAEMOPOIETIC NICHE. MSCS MAY INTERFERE WITH HAEMOPOIETIC AS WELL AS IMMUNE REGULATION. EVIDENCE SUGGESTS THAT BONE MARROW MSCS MAY BE INVOLVED IN IMMUNE-MEDIATED BMFS UNDERLYING PATHOPHYSIOLOGY, HARBORING EITHER NATIVE ABNORMALITIES AND/OR SECONDARY DEFECTS, CAUSED BY EXPOSURE TO ACTIVATED MARROW COMPONENTS. THIS REVIEW SUMMARIZES PREVIOUS AS WELL AS MORE RECENT INFORMATION RELATED TO THE BIOLOGIC/FUNCTIONAL CHARACTERISTICS OF BONE MARROW MSCS IN MYELODYSPLASTIC SYNDROMES, ACQUIRED APLASTIC ANEMIA, AND CHRONIC IDIOPATHIC NEUTROPENIA. 2013 4 2095 17 EPIGENETIC EFFECTS OF BENZENE IN HEMATOLOGIC NEOPLASMS: THE ALTERED GENE EXPRESSION. BENZENE CARCINOGENIC ABILITY HAS BEEN REPORTED, AND CHRONIC EXPOSURE TO BENZENE CAN BE ONE OF THE RISK ELEMENTS FOR SOLID CANCERS AND HEMATOLOGICAL NEOPLASMS. BENZENE IS ACKNOWLEDGED AS A MYELOTOXIN, AND IT IS ABLE TO AUGMENT THE RISK FOR THE ONSET OF ACUTE MYELOID LEUKEMIA, MYELODYSPLASTIC SYNDROMES, APLASTIC ANEMIA, AND LYMPHOMAS. POSSIBLE MECHANISMS OF BENZENE INITIATION OF HEMATOLOGICAL TUMORS HAVE BEEN IDENTIFIED, AS A GENOTOXIC EFFECT, AN ACTION ON OXIDATIVE STRESS AND INFLAMMATION AND THE PROVOCATION OF IMMUNOSUPPRESSION. HOWEVER, IT IS BECOMING EVIDENT THAT GENETIC ALTERATIONS AND THE OTHER CAUSES ARE INSUFFICIENT TO FULLY JUSTIFY SEVERAL PHENOMENA THAT INFLUENCE THE ONSET OF HEMATOLOGIC MALIGNANCIES. ACQUIRED EPIGENETIC ALTERATIONS MAY PARTICIPATE WITH BENZENE LEUKEMOGENESIS, AS BENZENE MAY AFFECT NUCLEAR RECEPTORS, AND PROVOKE POST-TRANSLATIONAL ALTERATIONS AT THE PROTEIN LEVEL, THEREBY TOUCHING THE FUNCTION OF REGULATORY PROTEINS, COMPRISING ONCOPROTEINS AND TUMOR SUPPRESSOR PROTEINS. DNA HYPOMETHYLATION CORRELATES WITH STIMULATION OF ONCOGENES, WHILE THE HYPERMETHYLATION OF CPG ISLANDS IN PROMOTER REGIONS OF SPECIFIC TUMOR SUPPRESSOR GENES INHIBITS THEIR TRANSCRIPTION AND STIMULATES THE ONSET OF TUMORS. THE DISCOVERY OF THE SYSTEMS OF EPIGENETIC INDUCTION OF BENZENE-CAUSED HEMATOLOGICAL TUMORS HAS ALLOWED THE POSSIBILITY TO OPERATE WITH PHARMACOLOGICAL INTERVENTIONS ABLE OF STOPPING OR OVERTURNING THE NEGATIVE EFFECTS OF BENZENE. 2021 5 1053 19 CLINICAL IMPLICATIONS OF INTERFERON-GAMMA GENETIC AND EPIGENETIC VARIANTS. INTERFERON-GAMMA (IFN-GAMMA) IS AN INTEGRAL AND CRITICAL MOLECULE OF THE IMMUNE SYSTEM, WITH MULTIPLE FUNCTIONS, MOSTLY RELATED TO THE T HELPER TYPE 1 (TH1) RESPONSE TO INFECTION. IT IS CRITICAL FOR DEFENCE AGAINST MYCOBACTERIAL INFECTION AND IS OF INCREASING INTEREST IN DEFENCE AGAINST FUNGI. IN THIS ARTICLE, WE REVIEW THE GENETIC AND EPIGENETIC VARIANTS AFFECTING IFN-GAMMA EXPRESSION AND INVESTIGATE ITS ROLE IN DISEASE, WITH AN EMPHASIS ON FUNGAL DISEASES SUCH AS INVASIVE AND CHRONIC PULMONARY ASPERGILLOSIS. OVER 347 IFN-GAMMA GENE VARIANTS HAVE BEEN DESCRIBED, IN MULTIPLE ETHNIC POPULATIONS. MANY APPEAR TO CONFER A SUSCEPTIBILITY TO DISEASE, ESPECIALLY TUBERCULOSIS (TB) AND HEPATITIS, BUT ALSO SOME NON-INFECTIOUS CONDITIONS SUCH AS APLASTIC ANAEMIA, CERVICAL CANCER AND PSORIASIS. SEVERAL EPIGENETIC MODIFICATIONS ARE ALSO DESCRIBED, INCREASING IFN-GAMMA EXPRESSION IN TH1 LYMPHOCYTES AND REDUCING IFN-GAMMA EXPRESSION IN TH2 LYMPHOCYTES. RECOMBINANT IFN-GAMMA ADMINISTRATION IS LICENSED FOR THE PROPHYLAXIS OF INFECTION (BACTERIAL AND FUNGAL) IN PATIENTS WITH THE PHAGOCYTE FUNCTIONAL DEFICIENCY SYNDROME CHRONIC GRANULOMATOUS DISEASE, ALTHOUGH THE BENEFITS APPEAR LIMITED. INTERFERON-GAMMA THERAPY IS GIVEN TO PATIENTS WITH PROFOUND DEFECTS IN IFN-GAMMA AND INTERLEUKIN-12 PRODUCTION AND APPEARS TO BE BENEFICIAL FOR PATIENTS WITH INVASIVE ASPERGILLOSIS AND CRYPTOCOCCAL MENINGITIS, BUT THE STUDIES ARE NOT DEFINITIVE. A HIGH PROPORTION OF PATIENTS WITH CHRONIC PULMONARY ASPERGILLOSIS ARE POOR PRODUCERS OF IFN-GAMMA IN RESPONSE TO MULTIPLE STIMULI AND COULD ALSO BENEFIT FROM IFN-GAMMA ADMINISTRATION. THE INVESTIGATION AND MANAGEMENT OF PATIENTS WITH POSSIBLE OR DEMONSTRATED IFN-GAMMA DEFICIENCY IN ADULTHOOD IS POORLY STUDIED AND COULD BE GREATLY ENHANCED WITH THE INTEGRATION OF GENETIC DATA. 2014 6 588 21 BENZENE EXPOSURE IS ASSOCIATED WITH EPIGENETIC CHANGES (REVIEW). BENZENE IS A VOLATILE AROMATIC HYDROCARBON SOLVENT AND IS KNOWN AS ONE OF THE PREDOMINANT AIR POLLUTANTS IN THE ENVIRONMENT. CHRONIC EXPOSURE TO BENZENE IS KNOWN TO CAUSE APLASTIC ANEMIA AND INCREASED RISK OF ACUTE MYELOGENOUS LEUKEMIA IN HUMANS. ALTHOUGH THE MECHANISMS BY WHICH BENZENE CAUSES TOXICITY REMAIN TO BE FULLY ELUCIDATED, IT IS WIDELY ACCEPTED THAT ITS METABOLISM IS CRUCIAL TO ITS TOXICITY, WITH INVOLVEMENT OF ONE OR MORE REACTIVE METABOLITES. NOVEL APPROACHES AIMED AT EVALUATING DIFFERENT MECHANISMS BY WHICH BENZENE CAN IMPACT ON HUMAN HEALTH BY ALTERING GENE REGULATION HAVE BEEN DEVELOPED. AMONG THESE NOVEL APPROACHES, EPIGENETICS APPEARS TO BE PROMISING. THE PRESENT REVIEW ARTICLE SUMMARIZES THE MOST IMPORTANT FINDINGS, REPORTED FROM THE LITERATURE, ON EPIGENETIC MODIFICATIONS CORRELATED TO BENZENE EXPOSURE. A COMPUTERIZED SEARCH IN PUBMED WAS PERFORMED IN NOVEMBER 2014, USING SEARCH TERMS, INCLUDING 'BENZENE', 'EPIGENETIC', 'HISTONE MODIFICATIONS', 'DNA METHYLATION' AND 'MICRORNA'. EPIDEMIOLOGICAL AND EXPERIMENTAL STUDIES HAVE DEMONSTRATED THE POTENTIAL EPIGENETIC EFFECTS OF BENZENE EXPOSURE. SEVERAL OF THE EPIGENOMIC CHANGES OBSERVED IN RESPONSE TO ENVIRONMENTAL EXPOSURES MAY BE MECHANISTICALLY ASSOCIATED WITH SUSCEPTIBILITY TO DISEASES. HOWEVER, FURTHER ELUCIDATION OF THE MECHANISMS BY WHICH BENZENE ALTERS GENE EXPRESSION MAY IMPROVE PREDICTION OF THE TOXIC POTENTIAL OF NOVEL COMPOUNDS INTRODUCED INTO THE ENVIRONMENT, AND ALLOW FOR MORE TARGETED AND APPROPRIATE DISEASE PREVENTION STRATEGIES. 2016 7 275 17 AGE-RELATED CLONAL HAEMOPOIESIS IS ASSOCIATED WITH INCREASED EPIGENETIC AGE. AGE-RELATED CLONAL HAEMOPOIESIS (ARCH) IN HEALTHY INDIVIDUALS WAS INITIALLY OBSERVED THROUGH AN INCREASED SKEWING IN X-CHROMOSOME INACTIVATION [1]. MORE RECENTLY, SEVERAL GROUPS REPORTED THAT ARCH IS DRIVEN BY SOMATIC MUTATIONS [2], WITH THE MOST PREVALENT ARCH MUTATIONS BEING IN THE DNMT3A AND TET2 GENES, PREVIOUSLY DESCRIBED AS DRIVERS OF MYELOID MALIGNANCIES. ARCH IS ASSOCIATED WITH AN INCREASED RISK FOR HAEMATOLOGICAL CANCERS [2]. ARCH ALSO CONFERS AN INCREASED RISK FOR NON-HAEMATOLOGICAL DISEASES, SUCH AS CARDIOVASCULAR DISEASE, ATHEROSCLEROSIS, AND CHRONIC ISCHEMIC HEART FAILURE, FOR WHICH AGE IS A MAIN RISK FACTOR [3,4]. WHETHER ARCH IS LINKED TO ACCELERATED AGEING HAS REMAINED UNEXPLORED. THE MOST ACCURATE AND COMMONLY USED TOOLS TO MEASURE AGE ACCELERATION ARE EPIGENETIC CLOCKS: THEY ARE BASED ON AGE-RELATED METHYLATION DIFFERENCES AT SPECIFIC CPG SITES [5]. DEVIATIONS FROM CHRONOLOGICAL AGE TOWARDS AN INCREASED EPIGENETIC AGE HAVE BEEN ASSOCIATED WITH INCREASED RISK OF EARLIER MORTALITY AND AGE-RELATED MORBIDITIES [5,6]. HERE WE PRESENT EVIDENCE OF ACCELERATED EPIGENETIC AGE IN INDIVIDUALS WITH ARCH. 2019 8 3985 22 LONG-TERM MAINTENANCE OF THE MUCOSAL HEALING INDUCED BY AZACITIDINE THERAPY IN A PATIENT WITH INTESTINAL BEHCET'S-LIKE DISEASE ACCOMPANIED WITH MYELODYSPLASTIC SYNDROME INVOLVING TRISOMY 8. MYELODYSPLASTIC SYNDROMES (MDSS) ARE A GROUP OF MYELOID NEOPLASMS CHARACTERIZED BY BLOOD CELL DEFORMATION AND DYSFUNCTION, AND MDS WITH TRISOMY 8 IS CLOSELY LINKED WITH INTESTINAL BEHCET'S-LIKE DISEASES. INTESTINAL BEHCET'S-LIKE DISEASE IS REFRACTORY TO CONVENTIONAL THERAPIES, INCLUDING PREDNISOLONE, IMMUNOMODULATORS, AND ANTI-TUMOR NECROSIS FACTOR ALPHA AGENTS. HERE, WE DESCRIBE A 56-YEAR-OLD WOMAN WITH INTESTINAL BEHCET'S-LIKE DISEASE ASCRIBED TO MDS WITH TRISOMY 8 WHO HAD MULTIPLE INTRACTABLE INTESTINAL ULCERS. SHE PRESENTED WITH PERIODIC FEVER AND ABDOMINAL PAIN. THE GENETIC ANALYSIS SHOWED A HETEROZYGOUS E148Q MUTATION IN THE MEDITERRANEAN FEVER GENE. THE PATIENT DID NOT TOLERATE TREATMENT WITH COLCHICINE BECAUSE OF DIARRHEA; THEREFORE, AZACITIDINE THERAPY WAS INITIATED. ONE CYCLE OF AZACITIDINE THERAPY IMPROVED THE MULTIPLE INTESTINAL ULCERS, AND THE PERIODIC FEVER AND ABDOMINAL PAIN GRADUALLY DISAPPEARED. AFTER EIGHT CYCLES OF AZACITIDINE THERAPY, ILEOCOLONOSCOPY, HISTOLOGICAL ASSESSMENT AND CAPSULE ENDOSCOPY REVEALED MUCOSAL HEALING. AZACITIDINE THERAPY WAS CONTINUED, AND MUCOSAL HEALING WAS MAINTAINED FOR MORE THAN 2 YEARS. THIS CASE SUGGESTS THAT AZACITIDINE THERAPY WHICH HAS IMMUNOREGULATORY EFFECTS AND EPIGENETIC MODULATIONS, MIGHT CONTROL INTESTINAL BEHCET'S-LIKE DISEASE ASSOCIATED WITH MDS INVOLVING TRISOMY 8. 2019 9 5782 14 SPLICING ANOMALIES IN MYELOPROLIFERATIVE NEOPLASMS: PAVING THE WAY FOR NEW THERAPEUTIC VENUES. SINCE THE DISCOVERY OF SPLICEOSOME MUTATIONS IN MYELOID MALIGNANCIES, ABNORMAL PRE-MRNA SPLICING, WHICH HAS BEEN WELL STUDIED IN VARIOUS CANCERS, HAS ATTRACTED NOVEL INTEREST IN HEMATOLOGY. HOWEVER, DESPITE THE COMMON OCCURRENCE OF SPLICEOSOME MUTATIONS IN MYELO-PROLIFERATIVE NEOPLASMS (MPN), NOT MUCH IS KNOWN REGARDING THE CHARACTERIZATION AND MECHANISMS OF SPLICING ANOMALIES IN MPN. IN THIS ARTICLE, WE REVIEW THE CURRENT SCIENTIFIC LITERATURE REGARDING "SPLICING AND MYELOPROLIFERATIVE NEOPLASMS". WE FIRST ANALYSE THE CLINICAL SERIES REPORTING SPLICEOSOME MUTATIONS IN MPN AND THEIR CLINICAL CORRELATES. WE THEN PRESENT THE CURRENT KNOWLEDGE ABOUT MOLECULAR MECHANISMS BY WHICH THESE MUTATIONS PARTICIPATE IN THE PATHOGENESIS OF MPN OR OTHER MYELOID MALIGNANCIES. BESIDE SPLICEOSOME MUTATIONS, SPLICING ANOMALIES HAVE BEEN DESCRIBED IN MYELOPROLIFERATIVE NEOPLASMS, AS WELL AS IN ACUTE MYELOID LEUKEMIAS, A DREADFUL COMPLICATION OF THESE CHRONIC DISEASES. BASED ON SPLICING ANOMALIES REPORTED IN CHRONIC MYELOGENOUS LEUKEMIA AS WELL AS IN ACUTE LEUKEMIA, AND THE MECHANISMS PRESIDING SPLICING DEREGULATION, WE PROPOSE THAT ABNORMAL SPLICING PLAYS A MAJOR ROLE IN THE EVOLUTION OF MYELOPROLIFERATIVE NEOPLASMS AND MAY BE THE TARGET OF SPECIFIC THERAPEUTIC STRATEGIES. 2020 10 6898 12 [THE ADVANCE OF MODEL OF ACTION IN LOW-DOSE CHRONIC BENZENE EXPOSURE INDUCED HEMATOTOXICITY]. BENZENE IS CLASSIFIED AS GROUP 1 CARCINOGEN BY IARC. IT HAS BEEN FOUND THAT BENZENE INDUCES HEMATOTOXICITY EVEN IN LOW DOSE EXPOSURE. THE IDENTIFICATION OF KEY EVENTS DURING BENZENE INDUCED HEMATOTOXICTY LEADS TO ADJUSTMENT OF OCCUPATIONAL EXPOSURE LIMITS OF BENZENE. IN THIS REVIEW, WE FOCUS ON THE EXPOSURE, METABOLISM, TARGET ORGANS, KEY EPIGENETIC CHANGES, TOXICTY EFFECTS AND END POINTS OF LOW-DOSE CHRONIC BENZENE EXPOSURE INDUCED HEMATOTOXICITY AND FINALLY DISCUSS THE PERSPECTIVES ON THE FUTURE STUDY OF THIS AREA. 2015 11 1070 18 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 12 5911 17 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 13 3178 25 HAEMATOLOGIC MALIGNANCIES WITH UNFAVOURABLE GENE MUTATIONS BENEFIT FROM DONOR LYMPHOCYTE INFUSION WITH/WITHOUT DECITABINE FOR PROPHYLAXIS OF RELAPSE AFTER ALLOGENEIC HSCT: A PILOT STUDY. RELAPSE IS THE MAIN CAUSE OF TREATMENT FAILURE FOR LEUKAEMIA PATIENTS WITH UNFAVOURABLE GENE MUTATIONS WHO RECEIVE ALLOGENEIC HAEMATOPOIETIC STEM CELL TRANSPLANTATION (ALLO-HSCT). THERE IS NO CONSENSUS ON THE INDICATION OF DONOR LYMPHOCYTE INFUSION (DLI) FOR PROPHYLAXIS OF RELAPSE AFTER ALLO-HSCT. TO EVALUATE THE TOLERANCE AND EFFICACY OF PROPHYLACTIC DLI IN PATIENTS WITH UNFAVOURABLE GENE MUTATIONS SUCH AS FLT3-ITD, TP53, ASXL1, DNMT3A OR TET2, WE PERFORMED A PROSPECTIVE, SINGLE-ARM STUDY. PROPHYLACTIC USE OF DECITABINE FOLLOWED BY DLI WAS PLANNED IN PATIENTS WITH TP53 OR EPIGENETIC MODIFIER GENE MUTATIONS. THE PROPHYLAXIS WAS PLANNED IN 46 RECIPIENTS: IT WAS ADMINISTERED IN 28 PATIENTS AND IT WAS NOT ADMINISTERED IN 18 PATIENTS DUE TO CONTRAINDICATIONS. NO DLI-ASSOCIATED PANCYTOPENIA WAS OBSERVED. THE CUMULATIVE INCIDENCES OF GRADE II-IV AND III-IV ACUTE GRAFT-VERSUS-HOST DISEASE (GVHD) AT 100 DAYS POST-DLI WERE 25.8% AND 11.0%, RESPECTIVELY. THE RATES OF CHRONIC GVHD, NON-RELAPSE MORTALITY AND RELAPSE AT 3 YEARS POST-DLI WERE 21.6%, 25.0% AND 26.1%, RESPECTIVELY. THE 3-YEAR RELAPSE-FREE SURVIVAL AND OVERALL SURVIVAL (OS) RATES WERE 48.9% AND 48.2%, RESPECTIVELY. ACUTE GVHD (HR: 2.30, P = 0.016) AND RELAPSE (HR: 2.46, P = 0.003) AFTER DLI WERE INDEPENDENTLY ASSOCIATED WITH INFERIOR OS. DATA IN THE CURRENT STUDY SHOWED THE FEASIBILITY OF PROPHYLACTIC DLI WITH/WITHOUT DECITABINE IN THE EARLY STAGE AFTER ALLO-HSCT IN PATIENTS WITH UNFAVOURABLE GENE MUTATIONS. 2021 14 3871 17 JUVENILE MYELOMONOCYTIC LEUKEMIA - A BONA FIDE RASOPATHY SYNDROME. JUVENILE MYELOMONOCYTIC LEUKEMIA (JMML) IS A PEDIATRIC MYELODYSPLASTIC/MYELOPROLIFERATIVE NEOPLASM OVERLAP SYNDROME WITH SUSTAINED PERIPHERAL BLOOD MONOCYTOSIS, AGGRESSIVE FEATURES, AND POOR OUTCOMES. IN >90% OF CASES JMML IS DRIVEN BY GERMLINE OR SOMATIC MUTATIONS INVOLVING THE CANONICAL RAS PATHWAY (PTPN11, NRAS, CBL, KRAS AND NF1), WITH SOMATIC MUTATIONS/ALTERATIONS IN RAS PATHWAY GENES (SECOND HIT), SETBP1, ASXL1 AND JAK3 RESULTING IN DISEASE PROGRESSION. WHILE SPONTANEOUS REGRESSION HAS BEEN SEEN IN GERMLINE PTPN11 AND CBL MUTANT JMML, IN MOST PATIENTS, ALLOGENEIC STEM CELL TRANSPLANT IS THE ONLY CURATIVE MODALITY. JMML SHARES SEVERAL PHENOTYPIC FEATURES WITH ITS ADULT COUNTERPART PROLIFERATIVE, CHRONIC MYELOMONOCYTIC LEUKEMIA (PCMML). PCMML LARGELY OCCURS DUE TO RAS PATHWAY MUTATIONS THAT OCCUR IN THE CONTEXT OF AGE RELATED CLONAL HEMATOPOIESIS (TET2, SRSF2, ASXL1), WHILE JMML IS A BONA FIDE RASOPATHY, WITH ADDITIONAL SOMATIC MUTATIONS, INCLUDING IN EPIGENETIC REGULATORS GENES RESULTING IN DISEASE PROGRESSION. 2020 15 3160 15 GRAFT-VERSUS-HOST DISEASE PROPHYLAXIS: PATHOPHYSIOLOGY-BASED REVIEW ON CURRENT APPROACHES AND FUTURE DIRECTIONS. GRAFT-VERSUS-HOST DISEASE (GVHD) WAS FIRST DESCRIBED IN 1959, SINCE THEN MAJOR EFFORTS HAVE BEEN MADE IN ORDER TO UNDERSTAND ITS PHYSIOPATHOLOGY AND ANIMAL MODELS HAVE PLAYED A KEY ROLE. THREE STEPS, INVOLVING DIFFERENT PATHWAYS, HAVE BEEN RECOGNISED IN EITHER ACUTE AND CHRONIC GVHD, IDENTIFYING THEM AS TWO DISTINCT ENTITIES. IN ORDER TO REDUCE GVHD INCIDENCE AND SEVERITY, PROPHYLACTIC MEASURES WERE ADDED TO TRANSPLANT PROTOCOLS. THE COMBINATION OF A CALCINEURIN INHIBITOR (CNI) PLUS AN ANTIMETABOLITE REMAINS THE STANDARD OF CARE. BETTER KNOWLEDGE OF GVHD PATHOPHYSIOLOGY HAS MOVED THIS FIELD FORWARD AND NOWADAYS DIFFERENT DRUGS ARE BEING USED ON A DAILY BASIS. IMPROVING GVHD PROPHYLAXIS IS A MAJOR GOAL AS IT WOULD TRANSLATE INTO LESS NON-RELAPSE MORTALITY AND BETTER OVERALL SURVIVAL. AS COMPARED TO CNI PLUS METHOTREXATE THE COMBINATION OF CNI PLUS MYCOPHENOLATE MOPHETIL (MMF) ALLOWS US TO OBTAIN SIMILAR RESULTS IN TERMS OF GVHD INCIDENCE BUT A LOWER TOXICITY RATE IN TERMS OF NEUTROPENIA OR MUCOSITIS. THE USE OF ATG HAS BEEN RELATED TO A LOWER RISK OF ACUTE AND CHRONIC GVHD IN PROSPECTIVE RANDOMIZED TRIALS AS WELL AS THE USE OF POSTTRANSPLANT CYCLOPHOSPHAMIDE, WITH NO OR MARGINAL IMPACT ON OVERALL SURVIVAL BUT WITH AN IMPROVEMENT IN GVHD-RELAPSE FREE SURVIVAL (GRFS). THE USE OF SIROLIMUS HAS BEEN RELATED TO A LOWER RISK OF ACUTE GVHD AND SIGNIFICANTLY INFLUENCED OVERALL SURVIVAL IN ONE PROSPECTIVE RANDOMIZED TRIAL. OTHER PROSPECTIVE TRIALS HAVE EVALUATED THE USE OF RECEPTORS SUCH AS CCR5 OR ALPHA4BETA7 TO AVOID T-CELLS TRAFFICKING INTO GVHD TARGET ORGANS, CYTOKINE BLOCKERS OR IMMUNE CHECK POINT AGONISTS. ALSO, EPIGENETIC MODIFIERS HAVE SHOWN PROMISING RESULTS IN PHASE II TRIALS. ATTENTION SHOULD BE PAID TO GRAFT-VERSUS-LEUKEMIA, INFECTIONS AND IMMUNE RECOVERY BEFORE BRINGING NEW PROPHYLACTIC STRATEGIES TO CLINICAL PRACTICE. ALTHOUGH THE LIST OF NOVEL AGENTS FOR GVHD PROPHYLAXIS IS GROWING, RANDOMIZED TRIALS ARE STILL LACKING FOR MANY OF THEM. 2021 16 2981 15 GENETIC COMPLEXITY OF CHRONIC MYELOMONOCYTIC LEUKEMIA. IN RECENT YEARS CMML HAS RECEIVED INCREASED ATTENTION AS THE MOST COMMONLY OBSERVED MDS/MPN OVERLAP SYNDROME. RENEWED INTEREST HAS OCCURRED IN PART DUE TO WIDESPREAD ADOPTION OF NEXT-GENERATION SEQUENCING PANELS THAT HELP RENDER THE DIAGNOSIS IN THE ABSENCE OF MORPHOLOGIC DYSPLASIA. ALTHOUGH MOST CMML PATIENTS EXHIBIT SOMATIC MUTATIONS IN EPIGENETIC MODIFIERS, SPLICEOSOME COMPONENTS, TRANSCRIPTION FACTORS AND SIGNAL TRANSDUCTION GENES, IT IS INCREASINGLY CLEAR THAT A SMALL SUBSET HARBORS AN INHERITED PREDISPOSITION TO CMML AND OTHER MYELOID NEOPLASMS. MORE INTRIGUING IS THE FACT THAT THE MUTATIONAL SPECTRUM OBSERVED IN CMML IS FOUND IN OTHER TYPES OF MYELOID LEUKEMIAS, BEGGING THE QUESTION OF HOW SIMILAR GENETIC BACKGROUNDS CAN LEAD TO SUCH DIVERGENT CLINICAL PHENOTYPES. IN THIS REVIEW WE PRESENT A CONTEMPORARY SNAPSHOT OF THE GENETIC COMPLEXITY INHERENT TO CMML, EXPLORE THE RELATIONSHIP BETWEEN GENOTYPE-PHENOTYPE AND PRESENT A STEPWISE MODEL OF CMML PATHOGENESIS AND PROGRESSION. 2021 17 2277 20 EPIGENETIC REGULATION BY ASXL1 IN MYELOID MALIGNANCIES. MYELOID MALIGNANCIES ARE CLONAL HEMATOPOIETIC DISORDERS THAT ARE COMPRISED OF A SPECTRUM OF GENETICALLY HETEROGENEOUS DISORDERS, INCLUDING MYELODYSPLASTIC SYNDROMES (MDS), MYELOPROLIFERATIVE NEOPLASMS (MPN), CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), AND ACUTE MYELOID LEUKEMIA (AML). MYELOID MALIGNANCIES ARE CHARACTERIZED BY EXCESSIVE PROLIFERATION, ABNORMAL SELF-RENEWAL, AND/OR DIFFERENTIATION DEFECTS OF HEMATOPOIETIC STEM CELLS (HSCS) AND MYELOID PROGENITOR CELLS HEMATOPOIETIC STEM/PROGENITOR CELLS (HSPCS). MYELOID MALIGNANCIES CAN BE CAUSED BY GENETIC AND EPIGENETIC ALTERATIONS THAT PROVOKE KEY CELLULAR FUNCTIONS, SUCH AS SELF-RENEWAL, PROLIFERATION, BIASED LINEAGE COMMITMENT, AND DIFFERENTIATION. ADVANCES IN NEXT-GENERATION SEQUENCING LED TO THE IDENTIFICATION OF MULTIPLE MUTATIONS IN MYELOID NEOPLASMS, AND MANY NEW GENE MUTATIONS WERE IDENTIFIED AS KEY FACTORS IN DRIVING THE PATHOGENESIS OF MYELOID MALIGNANCIES. THE POLYCOMB PROTEIN ASXL1 WAS IDENTIFIED TO BE FREQUENTLY MUTATED IN ALL FORMS OF MYELOID MALIGNANCIES, WITH MUTATIONAL FREQUENCIES OF 20%, 43%, 10%, AND 20% IN MDS, CMML, MPN, AND AML, RESPECTIVELY. SIGNIFICANTLY, ASXL1 MUTATIONS ARE ASSOCIATED WITH A POOR PROGNOSIS IN ALL FORMS OF MYELOID MALIGNANCIES. THE FACT THAT ASXL1 MUTATIONS ARE ASSOCIATED WITH POOR PROGNOSIS IN PATIENTS WITH CMML, MDS, AND AML, POINTS TO THE POSSIBILITY THAT ASXL1 MUTATION IS A KEY FACTOR IN THE DEVELOPMENT OF MYELOID MALIGNANCIES. THIS REVIEW SUMMARIZES THE RECENT ADVANCES IN UNDERSTANDING MYELOID MALIGNANCIES WITH A SPECIFIC FOCUS ON ASXL1 MUTATIONS. 2023 18 2956 16 GENETIC AND EPIGENETIC FACTORS INTERACTING WITH CLONAL HEMATOPOIESIS RESULTING IN CHRONIC MYELOMONOCYTIC LEUKEMIA. PURPOSE OF REVIEW: SINCE 2016, THE WHO HAS RECOGNIZED THE SIGNIFICANT PHENOTYPIC HETEROGENEITY OF CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AS A MYELODYSPLASTIC SYNDROME/MYELOPROLIFERATIVE NEOPLASM (MDS/MPN) OVERLAP DISEASE. ALTHOUGH SHARING MANY SOMATIC MUTATIONS WITH MDS AND MPN, THE PURPOSE OF THIS REVIEW IS TO PUT RECENT BIOLOGICAL FINDINGS OF CMML IN THE CONTEXT OF EVOLUTIONARY THEORY, HIGHLIGHTING IT AS A DISTINCT EVOLUTIONARY TRAJECTORY OCCURRING IN THE CONTEXT OF CLONAL HEMATOPOIESIS. RECENT FINDINGS: CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL (CHIP), WITH A MUTATIONAL SPECTRUM AND PREVALENCE CORRELATED WITH AGE, HAS BEEN DEFINED. ENRICHED IN DNMT3A, TET2, AND ASXL1 MUTATIONS, CLONAL EVOLUTION CAN PROGRESS INTO VARIOUS EVOLUTIONARY TRAJECTORIES INCLUDING CMML. IMPACT OF FOUNDER MUTATIONS (PRIMARILY TET2) ON INCREASED HEMATOPOIETIC STEM CELL FITNESS HAS BEEN WELL CHARACTERIZED. EPISTATIC INTERACTIONS BETWEEN MUTATIONS AND EPIGENETIC EVENTS HAVE BEEN EXPLORED, BOTH IN CMML AND ITS PEDIATRIC COUNTERPART JUVENILE MYELOMONOCYTIC LEUKEMIA, INCLUDING CMML TRANSFORMATION TO ACUTE MYELOID LEUKEMIA. TOGETHER, THESE FINDINGS HAVE CONTRIBUTED SIGNIFICANTLY TOWARD CMML EVOLUTIONARY DYNAMICS. SUMMARY: DESPITE RELATIVELY FEW 'DRIVER' MUTATIONS IN CMML, EVOLUTIONARY DEVELOPMENT OF CHRONIC LEUKEMIA REMAINS INCOMPLETELY UNDERSTOOD. RECENT STUDIES HAVE SHED LIGHT ON THE IMPORTANCE OF STUDYING EPIGENETIC CONSEQUENCES OF MUTATIONS AND EPISTASIS BETWEEN KEY MUTATIONS TO BETTER UNDERSTAND CLONAL ARCHITECTURE AND EVOLUTIONARY DYNAMICS. 2020 19 5789 20 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 20 4549 21 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