1 791 128 CELLULAR AND MOLECULAR NETWORKS IN CHRONIC MYELOID LEUKEMIA: THE LEUKEMIC STEM, PROGENITOR AND STROMAL CELL INTERPLAY. THE USE OF IMATINIB, SECOND AND THIRD GENERATION ABL TYROSINE KINASE INHIBITORS (TKI) (I.E. DASATINIB, NILOTINIB, BOSUTINIB AND PONATINIB) MADE CML A CLINICALLY MANAGEABLE AND, IN A SMALL PERCENTAGE OF CASES, A CURED DISEASE. TKI THERAPY ALSO TURNED CML BLASTIC TRANSFORMATION INTO A RARE EVENT; HOWEVER, DISEASE PROGRESSION STILL OCCURS IN THOSE PATIENTS WHO ARE REFRACTORY, NOT COMPLIANT WITH TKI THERAPY OR DEVELOP RESISTANCE TO MULTIPLE TKIS. IN THE PAST FEW YEARS, IT BECAME CLEAR THAT THE BCRABL1 ONCOGENE DOES NOT OPERATE ALONE TO DRIVE DISEASE EMERGENCE, MAINTENANCE AND PROGRESSION. INDEED, IT SEEMS THAT BONE MARROW (BM) MICROENVIRONMENT-GENERATED SIGNALS AND CELL AUTONOMOUS BCRABL1 KINASE-INDEPENDENT GENETIC AND EPIGENETIC ALTERATIONS ALL CONTRIBUTE TO: I. PERSISTENCE OF A QUIESCENT LEUKEMIC STEM CELL (LSC) RESERVOIR, II. INNATE OR ACQUIRED RESISTANCE TO TKIS, AND III. PROGRESSION INTO THE FATAL BLAST CRISIS STAGE. HEREIN, WE REVIEW THE INTRICATE LEUKEMIC NETWORK IN WHICH ABERRANT, BUT FINELY TUNED, SURVIVAL, MITOGENIC AND SELF-RENEWAL SIGNALS ARE GENERATED BY LEUKEMIC PROGENITORS, STROMAL CELLS, IMMUNE CELLS AND METABOLIC MICROENVIRONMENTAL CONDITIONS (E.G. HYPOXIA) TO PROMOTE LSC MAINTENANCE AND BLASTIC TRANSFORMATION. 2017 2 4562 22 MYELODYSPLASTIC SYNDROME/MYELOPROLIFERATIVE NEOPLASM OVERLAP SYNDROMES: A FOCUSED REVIEW. MYELODYSPLASTIC SYNDROME (MDS)/MYELOPROLIFERATIVE NEOPLASM (MPN) OVERLAP SYNDROMES ARE UNIQUE MYELOID NEOPLASMS, WITH OVERLAPPING FEATURES OF MDS AND MPN. THEY CONSIST OF FOUR ADULT ONSET ENTITIES INCLUDING CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), MDS/MPN-RING SIDEROBLASTS-THROMBOCYTOSIS (MDS/MPN-RS-T), BCR-ABL1 NEGATIVE ATYPICAL CHRONIC MYELOID LEUKEMIA (ACML) AND MDS/MPN-UNCLASSIFIABLE (MDS/MPN-U); WITH JUVENILE MYELOMONOCYTIC LEUKEMIA (JMML) BEING THE ONLY PEDIATRIC ONSET ENTITY. AMONG THESE OVERLAP NEOPLASMS, CMML IS THE MOST FREQUENT AND IS HALLMARKED BY THE PRESENCE OF SUSTAINED PERIPHERAL BLOOD MONOCYTOSIS WITH RECURRENT MUTATIONS INVOLVING TET2 (60%), SRSF2 (50%) AND ASXL1 (40%); WITH RAS PATHWAY MUTATIONS AND JAK2V617F BEING RELATIVELY ENRICHED IN PROLIFERATIVE CMML SUBTYPES (WBC >/=13 X 109/L). CMML USUALLY PRESENTS IN THE 7TH DECADE OF LIFE, WITH A MALE PREPONDERANCE AND IS ASSOCIATED WITH A MEDIAN OVERALL SURVIVAL OF <36 MONTHS. ADVERSE PROGNOSTICATORS IN CMML INCLUDE INCREASING AGE, HIGH WBC, PRESENCE OF CIRCULATING IMMATURE MYELOID CELLS, ANEMIA, THROMBOCYTOPENIA AND TRUNCATING ASXL1 MUTATIONS. WHILE ALLOGENEIC STEM CELL TRANSPLANTATION REMAINS THE ONLY CURATIVE OPTION, GIVEN THE LATE ONSET OF THIS NEOPLASM AND HIGH FREQUENCY OF COMORBIDITIES, MOST PATIENTS REMAIN INELIGIBLE. HYPOMETHYLATING AGENTS SUCH AS AZACITIDINE, DECITABINE AND ORAL DECITABINE/CEDAZURIDINE HAVE BEEN US FDA APPROVED FOR THE MANAGEMENT OF CMML, WITH OVERALL RESPONSE RATES OF 40-50% AND COMPLETE REMISSION RATES OF <20%. WHILE THESE AGENTS EPIGENETICALLY RESTORE HEMATOPOIESIS IN A SUBSET OF RESPONDING PATIENTS, THEY DO NOT IMPACT MUTATIONAL ALLELE BURDENS AND EVENTUAL DISEASE PROGRESSION TO AML REMAINS INEVITABLE. NEWER TREATMENT MODALITIES EXPLOITING EPIGENETIC, SIGNALING AND SPLICING ABNORMALITIES COMMONLY SEEN IN CMML ARE MUCH NEEDED. 2020 3 4533 37 MULTIPLE GENE KNOCKDOWN STRATEGIES FOR INVESTIGATING THE PROPERTIES OF HUMAN LEUKEMIA STEM CELLS AND EXPLORING NEW THERAPIES. THE PAST TWO DECADES HAVE WITNESSED SIGNIFICANT STRIDES IN LEUKEMIA THERAPIES THROUGH APPROVAL OF THERAPEUTIC INHIBITORS TARGETING ONCOGENE-DRIVING DYSREGULATED TYROSINE KINASE ACTIVITIES AND KEY EPIGENETIC AND APOPTOSIS REGULATORS. ALTHOUGH THESE DRUGS HAVE BROUGHT ABOUT COMPLETE REMISSION IN THE MAJORITY OF PATIENTS, MANY PATIENTS FACE RELAPSE OR HAVE REFRACTORY DISEASE. THE MAIN FACTOR CONTRIBUTING TO RELAPSE IS THE PRESENCE OF A SMALL SUBPOPULATION OF DORMANT DRUG-RESISTANT LEUKEMIA CELLS THAT POSSESS STEM CELL FEATURES (TERMED AS LEUKEMIA STEM CELLS OR LSCS). THUS, OVERCOMING DRUG RESISTANCE AND TARGETING LSCS REMAIN MAJOR CHALLENGES FOR CURATIVE TREATMENT OF HUMAN LEUKEMIA. CHRONIC MYELOID LEUKEMIA (CML) IS A GOOD EXAMPLE, WITH RARE, PROPAGATING LSCS AND DRUG-RESISTANT CELLS THAT CANNOT BE ERADICATED BY BCR-ABL-DIRECTED TYROSINE KINASE INHIBITOR (TKI) MONOTHERAPY AND THAT ARE RESPONSIBLE FOR DISEASE RELAPSE/PROGRESSION. THEREFORE, IT IS IMPERATIVE TO IDENTIFY KEY PLAYERS IN REGULATING BCR-ABL1-DEPENDENT AND INDEPENDENT DRUG-RESISTANCE MECHANISMS, AND THEIR KEY PATHWAYS, SO THAT CML LSCS CAN BE SELECTIVELY TARGETED OR SENSITIZED TO TKIS. HERE, WE DESCRIBE SEVERAL EASILY ADAPTABLE GENE KNOCKDOWN APPROACHES IN CD34(+) CML STEM/PROGENITOR CELLS THAT CAN BE USED TO INVESTIGATE THE BIOLOGICAL PROPERTIES OF LSCS AND MOLECULAR EFFECTS OF GENES OF INTEREST (GOI), WHICH CAN BE FURTHER EXPLORED AS THERAPEUTIC MODALITIES AGAINST LSCS IN THE CONTEXT OF HUMAN LEUKEMIA. 2022 4 3872 34 JUVENILE MYELOMONOCYTIC LEUKEMIA-A COMPREHENSIVE REVIEW AND RECENT ADVANCES IN MANAGEMENT. JUVENILE MYELOMONOCYTIC LEUKEMIA (JMML) IS A RARE PEDIATRIC MYELODYSPLASTIC/MYELOPROLIFERATIVE NEOPLASM OVERLAP DISEASE. JMML IS ASSOCIATED WITH MUTATIONS IN THE RAS PATHWAY GENES RESULTING IN THE MYELOID PROGENITORS BEING SENSITIVE TO GRANULOCYTE MONOCYTE COLONY-STIMULATING FACTOR (GM-CSF). KARYOTYPE ABNORMALITIES AND ADDITIONAL EPIGENETIC ALTERATIONS CAN ALSO BE FOUND IN JMML. NEUROFIBROMATOSIS AND NOONAN'S SYNDROME HAVE A PREDISPOSITION FOR JMML. IN A FEW PATIENTS, THE RAS GENES (NRAS, KRAS, AND PTPN11) ARE MUTATED AT THE GERMLINE AND THIS USUALLY RESULTS IN A TRANSIENT MYELOPROLIFERATIVE DISORDER WITH A GOOD PROGNOSIS. JMML WITH SOMATIC RAS MUTATION BEHAVES AGGRESSIVELY. JMML PRESENTS WITH CYTOPENIAS AND LEUKEMIC INFILTRATION INTO ORGANS. THE LABORATORY FINDINGS INCLUDE HYPERLEUKOCYTOSIS, MONOCYTOSIS, INCREASED HEMOGLOBIN-F LEVELS, AND CIRCULATING MYELOID PRECURSORS. THE BLAST CELLS IN THE PERIPHERAL BLOOD/BONE-MARROW ASPIRATE ARE LESS THAN 20% AND THE ABSENCE OF THE BCR-ABL TRANSLOCATION HELPS TO DIFFERENTIATE FROM CHRONIC MYELOID LEUKEMIA. JMML SHOULD BE DIFFERENTIATED FROM IMMUNODEFICIENCIES, VIRAL INFECTIONS, INTRAUTERINE INFECTIONS, HEMOPHAGOLYMPHOHISTIOCYTOSIS, OTHER MYELOPROLIFERATIVE DISORDERS, AND LEUKEMIAS. CHEMOTHERAPY IS EMPLOYED AS A BRIDGE TO HSCT, EXCEPT IN FEW WITH LESS AGGRESSIVE DISEASE, IN WHICH CHEMOTHERAPY ALONE CAN RESULT IN LONG TERM REMISSION. AZACITIDINE HAS SHOWN PROMISE AS A SINGLE AGENT TO STABILIZE THE DISEASE. THE PROGNOSIS OF JMML IS POOR WITH ABOUT 50% OF PATIENTS SURVIVING AFTER AN ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANT (HSCT). ALLOGENEIC HSCT IS THE ONLY KNOWN CURE FOR JMML TO DATE. MYELOABLATIVE CONDITIONING IS MOST COMMONLY USED WITH GRAFT VERSUS HOST DISEASE (GVHD) PROPHYLAXIS TAILORED TO THE AGGRESSIVENESS OF THE DISEASE. RELAPSES ARE COMMON EVEN AFTER HSCT AND A SECOND HSCT CAN SALVAGE A THIRD OF THESE PATIENTS. NOVEL OPTIONS IN THE TREATMENT OF JMML E.G., HYPOMETHYLATING AGENTS, MEK INHIBITORS, JAK INHIBITORS, TYROSINE KINASE INHIBITORS, ETC. ARE BEING EXPLORED. 2021 5 2402 40 EPIGENETIC REPROGRAMMING SENSITIZES CML STEM CELLS TO COMBINED EZH2 AND TYROSINE KINASE INHIBITION. A MAJOR OBSTACLE TO CURING CHRONIC MYELOID LEUKEMIA (CML) IS RESIDUAL DISEASE MAINTAINED BY TYROSINE KINASE INHIBITOR (TKI)-PERSISTENT LEUKEMIC STEM CELLS (LSC). THESE ARE BCR-ABL1 KINASE INDEPENDENT, REFRACTORY TO APOPTOSIS, AND SERVE AS A RESERVOIR TO DRIVE RELAPSE OR TKI RESISTANCE. WE DEMONSTRATE THAT POLYCOMB REPRESSIVE COMPLEX 2 IS MISREGULATED IN CHRONIC PHASE CML LSCS. THIS IS ASSOCIATED WITH EXTENSIVE REPROGRAMMING OF H3K27ME3 TARGETS IN LSCS, THUS SENSITIZING THEM TO APOPTOSIS UPON TREATMENT WITH AN EZH2-SPECIFIC INHIBITOR (EZH2I). EZH2I DOES NOT IMPAIR NORMAL HEMATOPOIETIC STEM CELL SURVIVAL. STRIKINGLY, TREATMENT OF PRIMARY CML CELLS WITH EITHER EZH2I OR TKI ALONE CAUSED SIGNIFICANT UPREGULATION OF H3K27ME3 TARGETS, AND COMBINED TREATMENT FURTHER POTENTIATED THESE EFFECTS AND RESULTED IN SIGNIFICANT LOSS OF LSCS COMPARED TO TKI ALONE, IN VITRO, AND IN LONG-TERM BONE MARROW MURINE XENOGRAFTS. OUR FINDINGS POINT TO A PROMISING EPIGENETIC-BASED THERAPEUTIC STRATEGY TO MORE EFFECTIVELY TARGET LSCS IN PATIENTS WITH CML RECEIVING TKIS. SIGNIFICANCE: IN CML, TKI-PERSISTENT LSCS REMAIN AN OBSTACLE TO CURE, AND APPROACHES TO ERADICATE THEM REMAIN A SIGNIFICANT UNMET CLINICAL NEED. WE DEMONSTRATE THAT EZH2 AND H3K27ME3 REPROGRAMMING IS IMPORTANT FOR LSC SURVIVAL, BUT RENDERS LSCS SENSITIVE TO THE COMBINED EFFECTS OF EZH2I AND TKI. THIS REPRESENTS A NOVEL APPROACH TO MORE EFFECTIVELY TARGET LSCS IN PATIENTS RECEIVING TKI TREATMENT. CANCER DISCOV; 6(11); 1248-57. (C)2016 AACR.SEE RELATED ARTICLE BY XIE ET AL., P. 1237THIS ARTICLE IS HIGHLIGHTED IN THE IN THIS ISSUE FEATURE, P. 1197. 2016 6 6689 25 VALPROIC ACID AT THERAPEUTIC PLASMA LEVELS MAY INCREASE 5-AZACYTIDINE EFFICACY IN HIGHER RISK MYELODYSPLASTIC SYNDROMES. PURPOSE: EPIGENETIC CHANGES PLAY A ROLE AND COOPERATE WITH GENETIC ALTERATIONS IN THE PATHOGENESIS OF MYELODYSPLASTIC SYNDROMES (MDS). WE CONDUCTED A PHASE II MULTICENTER STUDY ON THE COMBINATION OF THE DNA-METHYLTRANSFERASE INHIBITOR 5-AZACYTIDINE (5-AZA) AND THE HISTONE DEACETYLASE INHIBITOR VALPROIC ACID (VPA) IN PATIENTS WITH HIGHER RISK MDS. EXPERIMENTAL DESIGN: WE ENROLLED 62 PATIENTS WITH MDS (REFRACTORY ANEMIA WITH EXCESS BLASTS, 39 PATIENTS; REFRACTORY ANEMIA WITH EXCESS BLASTS IN TRANSFORMATION, 19 PATIENTS; AND CHRONIC MYELOMANOCYTIC LEUKEMIA (CMML), 4 PATIENTS) AND AN INTERNATIONAL PROGNOSTIC SCORING SYSTEM (IPSS) RATING OF INTERMEDIATE-2 (42 PATIENTS) OR HIGH (20 PATIENTS). VPA WAS GIVEN TO REACH A PLASMA CONCENTRATION OF >50 MICROG/ML, THEN 5-AZA WAS ADDED S.C. AT 75 MG/M(2) FOR 7 DAYS IN EIGHT MONTHLY CYCLES. RESULTS: THE MEDIAN OVERALL SURVIVAL WAS 14.4 MONTHS. AT A MEDIAN FOLLOW-UP OF 12 MONTHS (RANGE, 0.7-21.0), THE DISEASE PROGRESSED IN 20 PATIENTS, WITH 21% CUMULATIVE INCIDENCE OF PROGRESSION. OF 26 PATIENTS WHO COMPLETED EIGHT CYCLES, 30.7% OBTAINED COMPLETE OR PARTIAL REMISSION, 15.4% HAD A MAJOR HEMATOLOGIC IMPROVEMENT, WHEREAS 38.5% SHOWED STABLE DISEASE. DRUG-RELATED TOXICITY WAS MILD. FAVORABLE PROGNOSTIC FACTORS FOR SURVIVAL WERE IPSS INTERMEDIATE-2 AND PLASMA VPA OF > OR =50 MICROG/ML (LOG RANK = 0.013 AND 0.007, RESPECTIVELY). ANALYSIS OF POLYMORPHISMS IMPORTANT FOR THE METABOLISM OF THE DRUGS USED IN THE TRIAL SHOWED THAT CARRIERS OF THE CYP2C19*2 VARIANT OF CYTOCHROME P450 REQUIRED HIGHER VPA DOSES TO ACHIEVE THE TARGET VPA PLASMA CONCENTRATION OF 50 MICROG/ML ON DAY 1 OF 5-AZA TREATMENT (P = 0.0021). CONCLUSION: OUR DATA SHOW THAT THE 5-AZA/VPA COMBINATION IS ACTIVE AND SAFE IN PATIENTS WITH MDS WITH A POOR PROGNOSIS. ACHIEVEMENT OF VPA THERAPEUTIC LEVELS MAY INDEED INCREASE 5-AZA EFFICACY. 2009 7 6574 25 TREATMENT OF CHRONIC MYELOMONOCYTIC LEUKEMIA WITH 5-AZACYTIDINE: CASE REPORTS. EPIGENETIC THERAPY WITH HYPOMETHYLATING AGENT (5-AZACYTIDINE; AZA) IS COMMON IN THE MANAGEMENT OF SPECIFIC SUBTYPES OF MYELODYSPLASTIC SYNDROME (MDS), BUT THERE ARE ONLY FEW STUDIES IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) PATIENTS. IN THIS PAPER OUR EXPERIENCE WITH 3 CMML PATIENTS TREATED WITH AZA IS DESCRIBED. IN ONE PATIENT TRANSFUSION INDEPENDENCY WAS OBSERVED AFTER 4 TREATMENT CYCLES; IN ONE CASE A PARTIAL RESPONSE WAS RECORDED, BUT A PROGRESSION TO ACUTE MYELOID LEUKEMIA (AML) AFTER 13 AZA CYCLES HAS APPEARED. IN ONE PATIENT, AZA IN REDUCED DOSAGE WAS ADMINISTERED AS A BRIDGING TREATMENT BEFORE ALLOGENEIC STEM CELL TRANSPLANTATION (ASCT), BUT IN THE CONTROL BONE MARROW ASPIRATE (BEFORE ASCT) A PROGRESSION TO AML WAS RECORDED. FUTURE STUDIES ARE MANDATORY FOR EVALUATION OF NEW MOLECULAR AND CLINICAL FEATURES WHICH COULD PREDICT THE EFFICIENCY OF HYPOMETHYLATING AGENTS IN CMML THERAPY WITH RESPECT TO OVERALL SURVIVAL, EVENT-FREE SURVIVAL, QUALITY-ADJUSTED LIFE YEAR, AND PHARMACOECONOMY. 2012 8 32 39 A CASE OF TYROSINE KINASE INHIBITOR-RESISTANT CHRONIC MYELOID LEUKEMIA, CHRONIC PHASE WITH ASXL1 MUTATION. HEMATOLOGICAL MALIGNANCIES, INCLUDING CHRONIC MYELOID LEUKEMIA (CML), EXHIBIT ASXL1 MUTATIONS; HOWEVER, THE FUNCTION AND MOLECULAR MECHANISM OF THESE MUTATIONS REMAIN UNCLEAR. ASXL1 WAS ORIGINALLY IDENTIFIED AS TUMOR SUPPRESSOR GENE, IN WHICH LOSS OF FUNCTION CAUSES MYELODYSPLASTIC SYNDROME (MDS). ASXL1 MUTATIONS ARE COMMON AND ASSOCIATED WITH DISEASE PROGRESSION IN MYELOID MALIGNANCIES INCLUDING MDS, ACUTE MYELOID LEUKEMIA, AND SIMILARLY IN CML. IN MDS, ASXL1 MUTATIONS HAVE BEEN ASSOCIATED WITH POOR PROGNOSIS; HOWEVER, THE IMPACT OF ASXL1 MUTATIONS IN CML HAS NOT BEEN WELL DESCRIBED. A 31-YEAR-OLD MALE WAS DIAGNOSED AS CML-CHRONIC PHASE (CP). LABORATORY FINDINGS SHOWED A WHITE BLOOD CELL COUNT OF 187,200/MICROL, WITH ASYMPTOMATIC SPLENOMEGALY. BLAST COUNT WAS 5.0% IN PERIPHERAL BLOOD AND 7.3% IN BONE MARROW. THERE WAS NO ADDITIONAL CHROMOSOMAL ABNORMALITY EXCEPT FOR T(9;22)(Q34;Q11.2) BY CHROMOSOMAL ANALYSIS. AT ONSET, THE SOKAL SCORE WAS 1.4, INDICATING HIGH RISK. THE PATIENT RECEIVED TYROSINE KINASE INHIBITOR (TKI) THERAPY, COMPRISING NILOTINIB APPROXIMATELY 600 MG/DAY, BOSUTINIB APPROXIMATELY 600 MG/DAY, PONATINIB APPROXIMATELY 45 MG/DAY, AND DASATINIB APPROXIMATELY 100 MG/DAY. NEVERTHELESS, AFTER 1.5 YEARS OF CONTINUOUS TKI THERAPY, THE BEST OUTCOME WAS A HEMATOLOGICAL RESPONSE. ALTHOUGH ADDITIONAL CHROMOSOMAL ABERRATIONS AND ABL1 KINASE MUTATIONS WERE ANALYZED REPEATEDLY BEFORE AND DURING TKI THERAPY, KNOWN GENETIC ABNORMALITIES WERE NOT DETECTED. THEREAFTER, THE PATIENT UNDERWENT BONE MARROW TRANSPLANTATION FROM AN HLA 7/8 MATCHED UNRELATED DONOR (HLA-CW 1 LOCUS MISMATCH, GRAFT-VERSUS-HOST DIRECTION). THE PATIENT ACHIEVED NEUTROPHIL ENGRAFTMENT, 18 DAYS AFTER TRANSPLANTATION, LEADING TO COMPLETE REMISSION WITH AN UNDETECTABLE LEVEL OF BCR-ABL1 MRNA. THE PATIENT, HOWEVER, DIED FROM GRAFT-VERSUS-HOST DISEASE AND THROMBOTIC MICROANGIOPATHY AFTER 121 DAYS. GENE SEQUENCE ANALYSIS OF HIS CML CELL BEFORE STEM CELL TRANSPLANTATION REVEALED ASXL1 MUTATIONS. PHYSIOLOGICALLY, ASXL1 CONTRIBUTES TO EPIGENETIC REGULATION. IN THE CML-CP PATIENT IN THIS CASE REPORT, ASXL1 MUTATION CONFERRED RESISTANCE TO TKI THROUGH OBSCURE RESISTANCE MECHANISMS. EVEN THOUGH A MOLECULAR MECHANISM FOR TKI RESISTANCE IN ASXL1 MUTATION IN CML HAS REMAINED OBSCURE, EPIGENETIC MODULATION IS A PLAUSIBLE MODE OF CML DISEASE PROGRESSION. THE CLINICAL IMPACT INCLUDING PROGNOSIS OF ASXL1 FOR CML IS UNDERSCORED. AND THE TREATMENT STRATEGY OF CML WITH ASXL1 MUTATION HAS NOT BEEN ESTABLISHED. A DISCUSSION OF THIS CASE WAS EXPECTED TO FACILITATE TREATMENT OPTIONS. 2020 9 4681 20 NEW OPTIONS IN THE TREATMENT OF MYELODYSPLASTIC SYNDROME. MYELODYSPLASTIC SYNDROME (MDS) IS A HETEROGENEOUS GROUP OF PROGRESSIVE CHRONIC HEMATOPOIETIC DISORDERS, USUALLY PRESENTING AS REFRACTORY ANEMIA OR CYTOPENIA, WITH AN APPROXIMATELY 25% RISK OF PROGRESSION TOWARD ACUTE MYELOID LEUKAEIMA (AML), AND NO PROVEN CURATIVE TREATMENT. NOVEL BIOLOGICAL TREATMENT STRATEGIES TARGETING BOTH THE MALIGNANT BLOOD CELL AND ITS MICROENVIRONMENT CAN OVERCOME RESISTANCE TO CURRENT THERAPIES, AND REPRESENT A PROMISING TREATMENT PARADIGM FOR IMPROVING PATIENT OUTCOME. MANY OF THESE AGENTS HAVE MULTIPLE BIOLOGIC ACTIVITIES. THE OBJECTIVE OF THIS ARTICLE IS TO PRESENT A COMPARATIVE REVIEW OF CLASSIFICATION SYSTEMS IN MDS AND TO DISCUSS THE EVOLVING TRENDS IN THE TREATMENT OF MDS (IMMUNOSUPPRESIVE THERAPY, IMMUNOMODULATORY DRUGS, ARSENIC TRIOXIDE, PROTEASOME INHIBITORS, EPIGENETIC THERAPY). 2005 10 4485 23 MOLECULAR SIMILARITY BETWEEN MYELODYSPLASTIC FORM OF CHRONIC MYELOMONOCYTIC LEUKEMIA AND REFRACTORY ANEMIA WITH RING SIDEROBLASTS. CHRONIC MYELOMONOCYTIC LEUKEMIA IS SIMILAR TO BUT A SEPARATE ENTITY FROM BOTH MYELOPROLIFERATIVE NEOPLASMS AND MYELODYSPLASTIC SYNDROMES, AND SHOWS EITHER MYELOPROLIFERATIVE OR MYELODYSPLASTIC FEATURES. WE ASK WHETHER THIS DISTINCTION MAY HAVE A MOLECULAR BASIS. WE ESTABLISHED THE GENE EXPRESSION PROFILES OF 39 SAMPLES OF CHRONIC MYELOMONOCYTIC LEUKEMIA (INCLUDING 12 CD34-POSITIVE) AND 32 CD34-POSITIVE SAMPLES OF MYELODYSPLASTIC SYNDROMES BY USING AFFYMETRIX MICROARRAYS, AND STUDIED THE STATUS OF 18 GENES BY SANGER SEQUENCING AND ARRAY-COMPARATIVE GENOMIC HYBRIDIZATION IN 53 SAMPLES. ANALYSIS OF 12 MRNAS FROM CHRONIC MYELOMONOCYTIC LEUKEMIA ESTABLISHED A GENE EXPRESSION SIGNATURE OF 122 PROBE SETS DIFFERENTIALLY EXPRESSED BETWEEN PROLIFERATIVE AND DYSPLASTIC CASES OF CHRONIC MYELOMONOCYTIC LEUKEMIA. AS COMPARED TO PROLIFERATIVE CASES, DYSPLASTIC CASES OVER-EXPRESSED GENES INVOLVED IN RED BLOOD CELL BIOLOGY. WHEN APPLIED TO 32 MYELODYSPLASTIC SYNDROMES, THIS GENE EXPRESSION SIGNATURE WAS ABLE TO DISCRIMINATE REFRACTORY ANEMIAS WITH RING SIDEROBLASTS FROM REFRACTORY ANEMIAS WITH EXCESS OF BLASTS. BY COMPARING MRNAS FROM THESE TWO FORMS OF MYELODYSPLASTIC SYNDROMES WE DERIVED A SECOND GENE EXPRESSION SIGNATURE. THIS SIGNATURE SEPARATED THE MYELODYSPLASTIC AND MYELOPROLIFERATIVE FORMS OF CHRONIC MYELOMONOCYTIC LEUKEMIAS. THESE RESULTS WERE VALIDATED USING TWO INDEPENDENT GENE EXPRESSION DATA SETS. WE FOUND THAT MYELODYSPLASTIC CHRONIC MYELOMONOCYTIC LEUKEMIAS ARE CHARACTERIZED BY MUTATIONS IN TRANSCRIPTION/EPIGENETIC REGULATORS (ASXL1, RUNX1, TET2) AND SPLICING GENES (SRSF2) AND THE ABSENCE OF MUTATIONS IN SIGNALING GENES. MYELODYSPLASTIC CHRONIC MYELOMONOCYTIC LEUKEMIAS AND REFRACTORY ANEMIAS WITH RING SIDEROBLASTS SHARE A COMMON EXPRESSION PROGRAM SUGGESTING THEY ARE PART OF A CONTINUUM, WHICH IS NOT TOTALLY EXPLAINED BY THEIR SIMILAR BUT NOT, HOWEVER, IDENTICAL MUTATION SPECTRUM. 2013 11 3985 24 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 12 2277 25 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 13 2465 31 EPIGENETIC THERAPY WITH HYDRALAZINE AND MAGNESIUM VALPROATE REVERSES IMATINIB RESISTANCE IN PATIENTS WITH CHRONIC MYELOID LEUKEMIA. THE EPIGENETIC DRUGS HYDRALAZINE AND VALPROATE WERE ADMINISTERED IN A COMPASSIONATE MANNER TO 8 PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) REFRACTORY TO IMATINIB. TWO PATIENTS HAD A COMPLETE HEMATOLOGIC RESPONSE (25%),1 MAJOR CYTOGENETIC RESPONSE, 1 COMPLETE CYTOGENETIC RESPONSE (25% ANY CYTOGENETIC RESPONSE), AND 3 (37.5%)STABLE DISEASE. NO GRADE 3 OR 4 TOXICITY WAS OBSERVED. THESE RESULTS SHOW THE ABILITY OF EPIGENETIC THERAPY TO REVERT IMATINIB RESISTANCE. BACKGROUND: EPIGENETIC ALTERATIONS PARTICIPATE IN THE DEVELOPMENT OF ACQUIRED RESISTANCE TO IMATINIB, HENCE, THE DNA METHYLATION, AND HISTONE DEACETYLASE INHIBITORS HYDRALAZINE AND VALPROATE, RESPECTIVELY, HAS THE POTENTIAL TO OVERCOME IT. PATIENT AND METHODS: A SERIES OF 8 PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) REFRACTORY TO IMATINIB MESYLATE WITH NO ACCESS TO SECOND-GENERATION TYROSINE KINASE INHIBITORS WERE TREATED WITH HYDRALAZINE AND VALPROATE IN A COMPASSIONATE MANNER. CLINICAL EFFICACY AND SAFETY OF THESE DRUGS ADDED TO IMATINIB MESYLATE WERE EVALUATED. RESULTS: TWO PATIENTS WERE IN THE BLAST PHASE, 5 WERE IN THE ACCELERATED PHASE, AND 1 WAS IN THE CHRONIC PHASE. ALL THE PATIENTS CONTINUED WITH THE SAME DOSE OF IMATINIB THAT THEY HAD BEEN RECEIVING AT THE TIME OF DEVELOPMENT OF RESISTANCE, WITH A MEDIAN DOSE OF 600 MG DAILY (RANGE, 400-800 MG). THE MEDIAN TIME FROM DIAGNOSIS OF CML TO THE START OF HYDRALAZINE AND VALPROATE WAS 53.6 MONTHS (RANGE, 19-84 MONTHS). TWO (25%) PATIENTS HAD A COMPLETE HEMATOLOGIC RESPONSE, ONE (12.5%) HAD AN MAJOR CYTOGENETIC RESPONSE, AND ONE (12.5%) HAD A COMPLETE CYTOGENETIC RESPONSE. THREE (37.5%) PATIENTS HAD STABLE DISEASE, AND ONLY ONE (12.5%) PATIENT FAILED TO RESPOND. AT A MEDIAN FOLLOW-UP TIME OF 18 MONTHS (RANGE, 3-18 MONTHS), THE MEDIAN SURVIVAL HAD NOT BEEN REACHED, AND THE PROJECTED OVERALL SURVIVAL WAS 63%. ALL THE PATIENTS HAD MILD NEUROLOGIC TOXICITY, INCLUDING DISTAL TREMOR AND SOMNOLENCE. NO GRADE 3 OR 4 TOXICITY WAS OBSERVED. CONCLUSIONS: OUR RESULTS SUGGEST THAT THE EPIGENETIC DRUGS HYDRALAZINE AND VALPROATE REVERT THE RESISTANCE TO IMATINIB IN PATIENTS WITH CML. 2012 14 5212 38 PRESERVATION OF QUIESCENT CHRONIC MYELOGENOUS LEUKEMIA STEM CELLS BY THE BONE MARROW MICROENVIRONMENT. THE MAJORITY OF LEUKEMIA PATIENTS ACHIEVING REMISSION ULTIMATELY RELAPSE. PERSISTENCE OF LEUKEMIA STEM CELLS (LSC) CAPABLE OF REGENERATING LEUKEMIA IS A MAJOR CAUSE OF RELAPSE. THERE IS A PRESSING NEED TO BETTER UNDERSTAND MECHANISMS OF LSC REGULATION AND THEIR RESISTANCE TO THERAPY IN ORDER TO IMPROVE OUTCOMES FOR LEUKEMIA. CHRONIC MYELOGENOUS LEUKEMIA (CML) IS A LETHAL MYELOPROLIFERATIVE DISORDER THAT THAT IS CAUSED BY HEMATOPOIETIC STEM CELL (HSC) TRANSFORMATION BY THE BCR-ABL TYROSINE KINASE. TREATMENT WITH TYROSINE KINASE INHIBITORS (TKI) HAS REVOLUTIONIZED CML TREATMENT, BUT FAILS TO ELIMINATE LSC RESPONSIBLE FOR PROPAGATING AND REGENERATING LEUKEMIA. THEREFORE, PATIENTS REQUIRE CONTINUED TREATMENT TO PREVENT RELAPSE. LEUKEMIC AND NORMAL STEM CELLS SHARE PROPERTIES OF QUIESCENCE AND SELF-RENEWAL, THAT ARE SUPPORTED BY BONE MARROW NICHES. PERSISTENCE OF LSC AFTER TKI TREATMENT IS RELATED TO TYROSINE KINASE INDEPENDENT MECHANISMS WHICH INCLUDE INTRINSIC PROPERTIES OF LSCS DETERMINED BY EPIGENETIC ALTERATIONS, ALTERED TRANSCRIPTIONAL REGULATORY NETWORKS OR MITOCHONDRIAL/METABOLIC CHANGES. IN ADDITION TO CELL INTRINSIC CHANGES, SIGNALS FROM THE BONE MARROW MICROENVIRONMENT (BMM) PLAY A CRITICAL ROLE IN PROTECTING LSC FROM TKI TREATMENT. EACH TYPE OF ALTERATION MAY OFFER POTENTIAL POINTS OF INTERVENTION FOR THERAPEUTIC TARGETING OF LSC. 2018 15 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 16 4760 35 NOVEL TREATMENTS OF ADULT T CELL LEUKEMIA LYMPHOMA. ADULT T CELL LEUKEMIA-LYMPHOMA (ATL) IS AN AGGRESSIVE MALIGNANCY SECONDARY TO CHRONIC INFECTION WITH THE HUMAN T CELL LEUKEMIA VIRUS TYPE I (HTLV-I) RETROVIRUS. ATL CARRIES A DISMAL PROGNOSIS. ATL CLASSIFIES INTO FOUR SUBTYPES (ACUTE, LYMPHOMA, CHRONIC, AND SMOLDERING) WHICH DISPLAY DIFFERENT CLINICAL FEATURES, PROGNOSIS AND RESPONSE TO THERAPY, HENCE REQUIRING DIFFERENT CLINICAL MANAGEMENT. SMOLDERING AND CHRONIC SUBTYPES RESPOND WELL TO ANTIRETROVIRAL THERAPY USING THE COMBINATION OF ZIDOVUDINE (AZT) AND INTERFERON-ALPHA (IFN) WITH A SIGNIFICANT PROLONGATION OF SURVIVAL. CONVERSELY, THE WATCH AND WAIT STRATEGY OR CHEMOTHERAPY FOR THESE INDOLENT SUBTYPES ALLIES WITH A POOR LONG-TERM OUTCOME. ACUTE ATL IS ASSOCIATED WITH CHEMO-RESISTANCE AND DISMAL PROGNOSIS. LYMPHOMA SUBTYPES RESPOND BETTER TO INTENSIVE CHEMOTHERAPY BUT SURVIVAL REMAINS POOR. ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION (HSCT) RESULTS IN LONG-TERM SURVIVAL IN ROUGHLY ONE THIRD OF TRANSPLANTED PATIENTS BUT ONLY A SMALL PERCENTAGE OF PATIENTS CAN MAKE IT TO TRANSPLANT. OVERALL, CURRENT TREATMENTS OF AGGRESSIVE ATL ARE NOT SATISFACTORY. PROGNOSIS OF REFRACTORY OR RELAPSED PATIENTS IS DISMAL WITH SOME ENCOURAGING RESULTS WHEN USING LENALIDOMIDE OR MOGAMULIZUMAB. TO OVERCOME RESISTANCE AND PREVENT RELAPSE, PRECLINICAL OR PILOT CLINICAL STUDIES USING TARGETED THERAPIES SUCH AS ARSENIC/IFN, MONOCLONAL ANTIBODIES, EPIGENETIC THERAPIES ARE PROMISING BUT WARRANT FURTHER CLINICAL INVESTIGATION. ANTI-ATL VACCINES INCLUDING TAX PEPTIDE-PULSED DENDRITIC CELLS, INDUCED TAX-SPECIFIC CTL RESPONSES IN ATL PATIENTS. FINALLY, BASED ON THE PROGRESS IN UNDERSTANDING THE PATHOPHYSIOLOGY OF ATL, AND THE RISK-ADAPTED TREATMENT APPROACHES TO DIFFERENT ATL SUBTYPES, TREATMENT STRATEGIES OF ATL SHOULD TAKE INTO ACCOUNT THE HOST IMMUNE RESPONSES AND THE HOST MICROENVIRONMENT INCLUDING HTLV-1 INFECTED NON-MALIGNANT CELLS. HEREIN, WE WILL PROVIDE A SUMMARY OF NOVEL TREATMENTS OF ATL IN VITRO, IN VIVO, AND IN EARLY CLINICAL TRIALS. 2020 17 2719 28 EXOME SEQUENCING REVEALS DNMT3A AND ASXL1 VARIANTS ASSOCIATE WITH PROGRESSION OF CHRONIC MYELOID LEUKEMIA AFTER TYROSINE KINASE INHIBITOR THERAPY. OBJECTIVE: THE DEVELOPMENT OF TYROSINE KINASE INHIBITORS (TKIS) HAS SIGNIFICANTLY IMPROVED THE TREATMENT OF CHRONIC MYELOID LEUKEMIA (CML). HOWEVER, APPROXIMATELY ONE THIRD OF PATIENTS ARE RESISTANT TO TKI AND/OR PROGRESS TO ADVANCED DISEASE STAGES. TKI THERAPY FAILURE HAS A WELL-KNOWN ASSOCIATION WITH ABL1 KINASE DOMAIN (KD) MUTATIONS, BUT ONLY AROUND HALF OF TKI NON-RESPONDERS HAVE DETECTABLE ABL1 KD MUTATIONS. METHOD: WE ATTEMPT TO IDENTIFY GENETIC MARKERS ASSOCIATED WITH TKI THERAPY FAILURE IN 13 PATIENTS (5 RESISTANT, 8 PROGRESSED) WITHOUT ABL1 KD MUTATIONS USING WHOLE-EXOME SEQUENCING. RESULTS: IN 6 PATIENTS, WE DETECTED MUTATIONS IN 6 GENES COMMONLY MUTATED IN OTHER MYELOID NEOPLASMS: ABL1, ASXL1, DNMT3A, IDH1, SETBP1, AND TP63. WE THEN USED TARGETED DEEP SEQUENCING TO VALIDATE OUR FINDING IN AN INDEPENDENT COHORT CONSISTING OF 100 CML PATIENTS WITH VARYING DRUG RESPONSES (74 RESPONSIVE, 18 RESISTANT, AND 8 PROGRESSED PATIENTS). MUTATIONS IN GENES ASSOCIATED WITH EPIGENETIC REGULATIONS SUCH AS DNMT3A AND ASXL1 SEEM TO PLAY AN IMPORTANT ROLE IN THE PATHOGENESIS OF CML PROGRESSION AND TKI-RESISTANCE INDEPENDENT OF ABL1 KD MUTATIONS. CONCLUSION: THIS STUDY SUGGESTS THE INVOLVEMENT OF OTHER SOMATIC MUTATIONS IN THE DEVELOPMENT OF TKI RESISTANT PROGRESSION TO ADVANCED DISEASE STAGES IN CML, PARTICULARLY IN PATIENTS LACKING ABL1 KD MUTATIONS. 2017 18 1311 28 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 19 1242 29 CURRENT AND NOVEL THERAPEUTIC APPROACHES IN MYELODYSPLASTIC SYNDROMES. MYELODYSPLASTIC SYNDROMES (MDS) ARE A HETEROGENEOUS GROUP OF HEMATOLOGIC NEOPLASMS WITH AN ANNUAL INCIDENCE OF 4.1 CASES PER 100,000 AMERICANS. PATIENTS WITH MDS SUFFER FROM CHRONIC CYTOPENIAS THAT MAY LEAD TO RECURRENT TRANSFUSIONS, INFECTIONS, AND INCREASED RISK FOR BLEEDING. THEY ARE ALSO AT RISK FOR PROGRESSION TO ACUTE MYELOID LEUKEMIA. ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION IS THE ONLY POTENTIALLY CURATIVE TREATMENT FOR MDS, ALTHOUGH 3 DRUGS HAVE BEEN APPROVED BY THE US FOOD AND DRUG ADMINISTRATION FOR ITS TREATMENT: LENALIDOMIDE, 5-AZACITIDINE, AND DECITABINE. THESE THERAPIES CAN BE EFFECTIVE IN THE RELIEF OF CYTOPENIAS, ACHIEVEMENT OF CYTOGENETIC REMISSIONS, AND REDUCTION IN BONE MARROW BLASTS. 5-AZACITIDINE HAS ALSO BEEN SHOWN TO IMPROVE OVERALL SURVIVAL. HOWEVER, THERE REMAIN MANY UNMET NEEDS IN THE TREATMENT OF MDS. BREAKTHROUGHS IN OUR UNDERSTANDING OF THE COMPLEX PATHOGENESIS OF MDS THROUGH EPIGENETIC, GENETIC, IMMUNOLOGIC, AND OTHER BIOLOGICAL MECHANISMS HAVE ALLOWED US TO DEVELOP NEW THERAPEUTIC STRATEGIES THAT CAN LEAD TO IMPROVEMENTS IN OUTCOMES IN MDS. IN THIS REVIEW, WE AIM TO PROVIDE AN OVERVIEW OF THE EVOLUTION IN CLASSIFCATION AND RISK STRATIFCATION IN MDS AND TO ILLUSTRATE HOW WE CAN USE THIS TO GUIDE US IN TAILORING THERAPEUTIC CHOICES IN THIS DISEASE. RESPONSES AND OUTCOMES RELATED TO COM MONLY USED MDS THERAPIES WILL BE DISCUSSED TOGETHER WITH NOVEL THERAPIES THAT HAVE EVOLVED WITH THE IMPROVED UNDERSTANDING OF MDS PATHOPHYSIOLOGY. 2014 20 6437 27 THERAPEUTIC ADVANCES IN LEUKEMIA AND MYELODYSPLASTIC SYNDROME OVER THE PAST 40 YEARS. MAJOR THERAPEUTIC PROGRESS HAS BEEN ACCOMPLISHED IN LEUKEMIA AND MYELODYSPLASTIC SYNDROME (MDS) OVER THE PAST 40 YEARS, WHICH MAY NOT BE FULLY APPRECIATED BY THE LARGER MEDICAL COMMUNITY. THE OBJECTIVE OF THIS REVIEW WAS TO BRIEFLY HIGHLIGHT THE TREATMENT BREAKTHROUGHS IN LEUKEMIA AND MDS. THERAPEUTIC PROGRESS HAPPENED THROUGH BETTER UNDERSTANDING OF DISEASE PATHOPHYSIOLOGIES AND RATIONAL DEVELOPMENT OF TARGETED AGENTS, LIKE IMATINIB MESYLATE IN CHRONIC MYELOID LEUKEMIA (CML), AND THROUGH ASTUTE, EMPIRICAL DISCOVERIES IN THE CLINIC, LIKE ALL-TRANS RETINOIC ACID AND ARSENIC TRIOXIDE IN ACUTE PROMYELOCYTIC LEUKEMIA (APL) AND CHLORODEOXYADENOSINE IN HAIRY CELL LEUKEMIA (HCL). TODAY, THE 5- TO 10-YEAR SURVIVAL RATES IN PATIENTS WITH APL AND HCL EXCEED 80%. IN PATIENTS WITH CML, IMATINIB THERAPY HAS BEEN ASSOCIATED WITH ESTIMATED 5- TO 7-YEAR SURVIVAL RATES FROM 85% TO 90%. IN PATIENTS WITH ADULT ACUTE LYMPHOCYTIC LEUKEMIA, MODERN INTENSIVE REGIMENS HAVE IMPROVED THE 5-YEAR SURVIVAL RATES FROM 20% UP TO 40%. IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA, CHEMOIMMUNOTHERAPY RECENTLY PRODUCED HIGH RATES OF QUALITY RESPONSES AND IMPROVED LONG-TERM OUTCOME. IN YOUNGER PATIENTS WITH ACUTE MYELOID LEUKEMIA (AML), THE 5-YEAR SURVIVAL RATES RANGE FROM 40% TO 50%, ALTHOUGH ELDERLY AML REMAINS A THERAPEUTIC CHALLENGE. IN PATIENTS WITH MDS, IT WAS RECENTLY DEMONSTRATED THAT EPIGENETIC THERAPY WITH HYPOMETHYLATING AGENTS IMPROVED SURVIVAL. MUCH THERAPEUTIC PROGRESS HAS BEEN WITNESSED IN LEUKEMIA AND MDS, AND MUCH MORE IS EXPECTED TO OCCUR SOON. 2008