1 3560 134 IMPACT OF CLINICAL, CYTOGENETIC, AND MOLECULAR PROFILES ON LONG-TERM SURVIVAL AFTER TRANSPLANTATION IN PATIENTS WITH CHRONIC MYELOMONOCYTIC LEUKEMIA. CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) IS A HETEROGENEOUS GROUP OF CLONAL HEMATOPOIETIC MALIGNANCIES WITH VARIABLE CLINICAL AND MOLECULAR FEATURES. WE ANALYZED LONG-TERM RESULTS OF ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION IN PATIENTS WITH CMML AND DETERMINED CLINICAL AND MOLECULAR RISK FACTORS ASSOCIATED WITH OUTCOMES. DATA FROM 129 PATIENTS, AGED 7-74 (MEDIAN 55) YEARS, AT VARIOUS STAGES OF THE DISEASE AND TRANSPLANTED FROM RELATED OR UNRELATED DONORS WERE ANALYZED. USING A PANEL OF 75 GENES SOMATIC MUTATIONS PRESENT BEFORE HEMATOPOIETIC CELL TRANSPLANTATION WERE IDENTIFIED IN 52 PATIENTS. THE PROGRESSION-FREE SURVIVAL RATE AT 10 YEARS WAS 29%. THE MAJOR CAUSE OF DEATH WAS RELAPSE (32%), WHICH WAS SIGNIFICANTLY ASSOCIATED WITH ADVERSE CYTOGENETICS (HAZARD RATIO, 3.77; P=0.0002), CMML PROGNOSTIC SCORING SYSTEM (HAZARD RATIO, 14.3, P=0.01), AND MD ANDERSON PROGNOSTIC SCORES (HAZARD RATIO, 9.4; P=0.005). MORTALITY WAS ASSOCIATED WITH HIGH-RISK CYTOGENETICS (HAZARD RATIO, 1.88; P=0.01) AND HIGH HEMATOPOIETIC CELL TRANSPLANTATION COMORBIDITY INDEX (SCORE >/=4: HAZARD RATIO, 1.99; P=0.01). HIGH OVERALL MUTATION BURDEN (>/=10 MUTATIONS: HAZARD RATIO, 3.4; P=0.02), AND >/=4 MUTATED EPIGENETIC REGULATORY GENES (HAZARD RATIO 5.4; P=0.003) WERE LINKED TO RELAPSE. UNSUPERVISED CLUSTERING OF THE CORRELATION MATRIX REVEALED DISTINCT HIGH-RISK GROUPS WITH UNIQUE ASSOCIATIONS OF MUTATIONS AND CLINICAL FEATURES. CMML WITH A HIGH MUTATION BURDEN APPEARED TO BE DISTINCT FROM HIGH-RISK GROUPS DEFINED BY COMPLEX CYTOGENETICS. NEW TRANSPLANT STRATEGIES MUST BE DEVELOPED TO TARGET SPECIFIC DISEASE SUBGROUPS, STRATIFIED BY MOLECULAR PROFILING AND CLINICAL RISK FACTORS. 2020 2 4436 21 MOLECULAR EVOLUTION OF CHRONIC MYELOID LEUKAEMIA. CHRONIC MYELOID LEUKAEMIA (CML) IS A CLONAL DISORDER OF THE PLURIPOTENT HAEMATOPOIETIC STEM CELL. THE TYPICAL TRIPHASIC COURSE OF CML STARTS WITH THE PREMALIGNANT CHRONIC PHASE INITIATED BY BCR-ABL HYBRID ONCOGENE FORMATION. SECONDARY GENETIC AND EPIGENETIC ABERRATIONS ACCOMPANY THE PROGRESSION TO THE ACCELERATED PHASE AND FATAL BLASTIC CRISIS. PROPERLY TIMED BONE MARROW TRANSPLANTATION IN ELIGIBLE PATIENTS CAN RESULT IN DURABLE REMISSIONS OR CURE. BOTH OF THESE STATES ARE OFTEN ACCOMPANIED BY A LONG-TERM PERSISTENCE OF QUIESCENT LEUKAEMIC CELLS. ACCORDINGLY, A "FUNCTIONAL CURE" (I.E. TUMOUR DORMANCY INDUCTION), RATHER THAN COMPLETE ERADICATION OF THE MALIGNANT CELLS, IS AN ADEQUATE THERAPEUTICAL GOAL. THE LEVEL OF THE RESIDUAL BCR-ABL-POSITIVE CLONES SHOULD BE MONITORED AND SALVAGE TREATMENT INITIATED WHENEVER THESE QUIESCENT LEUKAEMIC CELLS EXIT THEIR DORMANT STATE. 2001 3 2402 29 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 4 32 40 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 5 5283 36 PROPHYLACTIC OR PREEMPTIVE LOW-DOSE AZACITIDINE AND DONOR LYMPHOCYTE INFUSION TO PREVENT DISEASE RELAPSE FOLLOWING ALLOGENEIC TRANSPLANTATION IN PATIENTS WITH HIGH-RISK ACUTE MYELOGENOUS LEUKEMIA OR MYELODYSPLASTIC SYNDROME. BECAUSE OF THE PERSISTENTLY HIGH RATES OF RELAPSE OF PATIENTS WITH HIGH-RISK ACUTE MYELOGENOUS LEUKEMIA (AML) AND MYELODYSPLASTIC SYNDROME (MDS) FOLLOWING ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION (ALLO-HSCT), POST-TRANSPLANTATION MAINTENANCE THERAPY HAS BEEN PROPOSED. WE PREVIOUSLY INITIATED A PHASE II TRIAL IN WHICH EPIGENETIC THERAPY WAS COMBINED WITH IMMUNOTHERAPY IN AN ATTEMPT TO REDUCE DISEASE RELAPSE. IN THAT STUDY, LOW-DOSE AZACITIDINE (AZA) AND ESCALATING DOSES OF DONOR LYMPHOCYTE INFUSION (DLI) WERE GIVEN AS POST-ALLO-HSCT MAINTENANCE TREATMENT. IN THE PRESENT STUDY, WE RETROSPECTIVELY ANALYZE A LARGER COHORT OF PATIENTS RECEIVING POST-TRANSPLANTATION MAINTENANCE THERAPY AND PROVIDE UPDATES ON SOME PATIENTS OF THE EARLIER STUDY. THE OBJECTIVES OF THE PRESENT STUDY WERE TO ANALYZE THE CUMULATIVE INCIDENCE OF RELAPSE (CIR), OVERALL SURVIVAL (OS), AND PROGRESSION-FREE SURVIVAL (PFS) AND THE INCIDENCE OF ACUTE AND CHRONIC GRAFT-VERSUS-HOST DISEASE (GVHD) OF PATIENTS WITH HIGH-RISK AML OR MDS RECEIVING POST-TRANSPLANTATION MAINTENANCE TREATMENT WITH AZA WITH OR WITHOUT DLI. WE RETROSPECTIVELY ANALYZED 77 PATIENTS (54 WITH AML, 23 WITH MDS) CONSIDERED AT HIGH RISK BASED ON EITHER THEIR GENOMIC OR CLINICAL STATUS AT TRANSPLANTATION. FOLLOWING ALLOGENEIC TRANSPLANTATION, THEY RECEIVED AT LEAST 1 CYCLE OF PROPHYLACTIC OR PREEMPTIVE LOW-DOSE AZA WITH OR WITHOUT ESCALATING DOSES OF DLI TO PREVENT DISEASE RELAPSE. ALMOST ONE-HALF OF THE PATIENTS (47%) WERE ABLE TO RECEIVE THE FULL 12 CYCLES OF SCHEDULED AZA, AND A MAJORITY (79%) RECEIVED AT LEAST 1 DLI. WITH A MEDIAN FOLLOW-UP OF 24 MONTHS, 19 PATIENTS (25%; 16 WITH AML, 3 WITH MDS) RELAPSED, AT A MEDIAN OF 9.8 MONTHS (RANGE, 4 TO 58.6 MONTHS), GIVING A 22% CIR AT 24 MONTHS. OS AND PFS AT 24 MONTHS WERE 70.8% AND 68.3%, RESPECTIVELY. THE CUMULATIVE INCIDENCES OF GRADE II-IV ACUTE GVHD AND CHRONIC GVHD WERE 27.4% AND 45%, RESPECTIVELY. ONLY A MINORITY OF PATIENTS (11%) REQUIRED DELAYED ADMINISTRATION OF AZA. THESE FINDINGS CONFIRM THAT AZA-DLI MAINTENANCE IS BOTH TOLERABLE AND EFFECTIVE IN REDUCING THE RISK OF POST-TRANSPLANTATION RELAPSE. 2021 6 791 22 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 7 955 21 CHRONIC MYELOID LEUKEMIA: MECHANISMS OF BLASTIC TRANSFORMATION. THE BCR-ABL1 ONCOPROTEIN TRANSFORMS PLURIPOTENT HSCS AND INITIATES CHRONIC MYELOID LEUKEMIA (CML). PATIENTS WITH EARLY PHASE (ALSO KNOWN AS CHRONIC PHASE [CP]) DISEASE USUALLY RESPOND TO TREATMENT WITH ABL TYROSINE KINASE INHIBITORS (TKIS), ALTHOUGH SOME PATIENTS WHO RESPOND INITIALLY LATER BECOME RESISTANT. IN MOST PATIENTS, TKIS REDUCE THE LEUKEMIA CELL LOAD SUBSTANTIALLY, BUT THE CELLS FROM WHICH THE LEUKEMIA CELLS ARE DERIVED DURING CP (SO-CALLED LEUKEMIA STEM CELLS [LSCS]) ARE INTRINSICALLY INSENSITIVE TO TKIS AND SURVIVE LONG TERM. LSCS OR THEIR PROGENY CAN ACQUIRE ADDITIONAL GENETIC AND/OR EPIGENETIC CHANGES THAT CAUSE THE LEUKEMIA TO TRANSFORM FROM CP TO A MORE ADVANCED PHASE, WHICH HAS BEEN SUBCLASSIFIED AS EITHER ACCELERATED PHASE OR BLASTIC PHASE DISEASE. THE LATTER RESPONDS POORLY TO TREATMENT AND IS USUALLY FATAL. HERE, WE DISCUSS WHAT IS KNOWN ABOUT THE MOLECULAR MECHANISMS LEADING TO BLASTIC TRANSFORMATION OF CML AND PROPOSE SOME NOVEL THERAPEUTIC APPROACHES. 2010 8 6609 30 TYROSINE KINASE INHIBITORS IN PH+ CHRONIC MYELOID LEUKEMIA THERAPY: A REVIEW. CHRONIC MYELOID LEUKAEMIA (CML) IS A CLONAL MYELOPROLIFERATIVE HEMATOPOIETIC STEM CELL DISORDER. DEREGULATED BCRABL FUSION TYROSINE KINASE ACTIVITY IS THE MAIN CAUSE OF CML DISEASE PATHOGENESIS, MAKING BCRABL AN IDEAL TARGET FOR INHIBITION. CURRENT TYROSINE KINASE INHIBITORS (TKIS) DESIGNED TO INHIBIT BCRABL ONCOPROTEIN ACTIVITY, HAVE COMPLETELY TRANSFORMED THE PROGNOSIS OF CML. INTERRUPTION OF TKI TREATMENT LEADS TO MINIMAL RESIDUAL DISEASE RESIDE (MRD), THOUGHT TO RESIDE IN TKIINSENSITIVE LEUKAEMIA STEM CELLS WHICH REMAIN A POTENTIAL RESERVOIR FOR DISEASE RELAPSE. THIS HIGHLIGHTS THE NEED TO DEVELOP NEW THERAPEUTIC STRATEGIES FOR CML EITHER AS SMALL MOLECULE MASTER TKIS OR PHYTOPHARMACEUTICALS DERIVED FROM NATURE TO ACHIEVE CHRONIC MOLECULAR REMISSION. THIS REVIEW OUTLINES THE PAST, PRESENT AND FUTURE THERAPEUTIC APPROACHES FOR CML INCLUDING COVERAGE OF RELEVANT MECHANISMS, WHETHER ABL DEPENDENT OR INDEPENDENT, AND EPIGENETIC FACTORS RESPONSIBLE FOR DEVELOPING RESISTANCE AGAINST TKIS. APPEARANCE OF MUTANT CLONES ALONG THE COURSE OF THERAPY EITHER PREEXISTING OR INDUCED DUE TO THERAPY IS STILL A CHALLENGE FOR THE CLINICIAN. A PROPOSED INVITRO MODEL OF GENERATING COLONY FORMING UNITS FROM CML STEM CELLS DERIVED FROM DIAGNOSTIC SAMPLES SEEMS TO BE ACHIEVABLE IN THE ERA OF HIGH THROUGHPUT TECHNOLOGY WHICH CAN TAKE CARE OF SINGLE CELL GENOMIC PROFILING. 2016 9 3530 25 IMATINIB (ST1571) PROVIDES ONLY LIMITED SELECTIVITY FOR CML CELLS AND TREATMENT MIGHT BE COMPLICATED BY SILENT BCR-ABL GENES. VERY PROMISING RESULTS HAVE BEEN OBTAINED IN CLINICAL TRIALS ON CHRONIC-PHASE CHRONIC MYELOID LEUKEMIA (CP-CML) PATIENTS TREATED WITH IMATINIB MESYLATE (IM; GLEEVECR, STI571), A BCR-ABL TYROSINE KINASE INHIBITOR. HOWEVER, WE FOUND THAT IM CAUSED CONSIDERABLE INHIBITION OF NORMAL HEMATOPOIETIC PROGENITOR CELLS UPON TREATING CONTROL BONE MARROW (BM) CULTURES. IN VITRO IM TREATMENT GAVE A DECREASE IN THE YIELD AND SIZE OF COLONIES FROM BM OF UNTREATED CP-CML PATIENTS THAT WAS ONLY TWO TO THREE TIMES THAT FROM THE NORMAL SAMPLES. MOREOVER, ABOUT 30% OF MYELOID PROGENITORS (CFU-GM) FROM CML BM STILL FORMED COLONIES IN THE PRESENCE OF IM, MOST OF WHICH HAD BCR-ABL RNA. ABOUT HALF OF THESE TREATED COLONIES ALSO DISPLAYED METHYLATION OF THE INTERNAL ABL PA PROMOTER, A CML-SPECIFIC EPIGENETIC ALTERATION, WHICH WAS USED IN THIS STUDY AS A MARKER FOR BCR-ABL TRANSLOCATION-CONTAINING CELLS. HOWEVER, ~5-8% OF THE TREATED OR THE UNTREATED CML BM-DERIVED COLONIES HAD NO DETECTABLE BCR-ABL RNA BY TWO OR THREE ROUNDS OF RT-PCR DESPITE BEING POSITIVE FOR THE INTERNAL STANDARD RNA AND DISPLAYING HALLMARKS OF CML, EITHER T(9;22)(Q34;QL 1) OR ABL PA METHYLATION. OUR RESULTS INDICATE THAT IM IS ONLY PARTIALLY SPECIFIC FOR CML PROGENITOR CELLS COMPARED TO NORMAL HEMATOPOIETIC PROGENITOR CELLS AND SUGGEST THAT SOME CML CELLS MAY HAVE A SILENT BCR-ABL ONCOGENE THAT COULD INTERFERE WITH THERAPY. 2003 10 2719 27 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 11 5612 38 SAFETY AND ACTIVITY OF RRX-001 IN PATIENTS WITH ADVANCED CANCER: A FIRST-IN-HUMAN, OPEN-LABEL, DOSE-ESCALATION PHASE 1 STUDY. BACKGROUND: EPIGENETIC ALTERATIONS HAVE BEEN STRONGLY ASSOCIATED WITH TUMOUR FORMATION AND RESISTANCE TO CHEMOTHERAPEUTIC DRUGS, AND EPIGENETIC MODIFICATIONS ARE AN ATTRACTIVE TARGET IN CANCER RESEARCH. RRX-001 IS ACTIVATED BY HYPOXIA AND INDUCES THE GENERATION OF REACTIVE OXYGEN AND NITROGEN SPECIES THAT CAN EPIGENETICALLY MODULATE DNA METHYLATION, HISTONE DEACETYLATION, AND LYSINE DEMETHYLATION. THE AIM OF THIS PHASE 1 STUDY WAS TO ASSESS THE SAFETY, TOLERABILITY, AND PHARMACOKINETICS OF RRX-001. METHODS: IN THIS OPEN-LABEL, DOSE-ESCALATION, PHASE 1 STUDY, WE RECRUITED ADULT PATIENTS (AGED >18 YEARS) WITH HISTOLOGICALLY OR CYTOLOGICALLY CONFIRMED DIAGNOSIS OF ADVANCED, MALIGNANT, INCURABLE SOLID TUMOURS FROM UNIVERSITY OF CALIFORNIA AT SAN DIEGO, CA, USA, AND SARAH CANNON RESEARCH INSTITUTE, NASHVILLE, TN, USA. KEY ELIGIBILITY CRITERIA INCLUDED EVALUABLE DISEASE, EASTERN COOPERATIVE GROUP PERFORMANCE STATUS OF 2 OR LESS, AN ESTIMATED LIFE EXPECTANCY OF AT LEAST 12 WEEKS, ADEQUATE LABORATORY PARAMETERS, DISCONTINUATION OF ALL PREVIOUS ANTINEOPLASTIC THERAPIES AT LEAST 6 WEEKS BEFORE INTERVENTION, AND NO RESIDUAL SIDE-EFFECTS FROM PREVIOUS THERAPIES. PATIENTS WERE ASSIGNED TO RECEIVE INTRAVENOUS INFUSIONS OF RRX-001 AT INCREASING DOSES (10 MG/M(2), 16.7 MG/M(2), 24.6 MG/M(2), 33 MG/M(2), 55 MG/M(2), AND 83 MG/M(2)) EITHER ONCE OR TWICE-WEEKLY FOR AT LEAST 4 WEEKS, WITH AT LEAST THREE PATIENTS PER DOSE COHORT AND ALLOWING A 2-WEEK OBSERVATION PERIOD BEFORE DOSE ESCALATION. SAMPLES FOR SAFETY AND PHARMACOKINETICS ANALYSIS, INCLUDING STANDARD CHEMISTRY AND HAEMATOLOGICAL PANELS, WERE TAKEN ON EACH TREATMENT DAY. THE PRIMARY OBJECTIVE WAS TO ASSESS SAFETY, TOLERABILITY, AND DOSE-LIMITING TOXIC EFFECTS OF RRX-001, TO DETERMINE SINGLE-DOSE PHARMACOKINETICS, AND TO IDENTIFY A RECOMMENDED DOSE FOR PHASE 2 TRIALS. ALL ANALYSES WERE DONE PER PROTOCOL. ACCRUAL IS COMPLETE AND FOLLOW-UP IS STILL ON-GOING. THIS TRIAL IS REGISTERED WITH CLINICALTRIALS.GOV, NUMBER NCT01359982. FINDINGS: BETWEEN OCT 10, 2011, AND MARCH 18, 2013, WE ENROLLED 25 PATIENTS AND TREATED SIX PATIENTS IN THE 10 MG/M(2) COHORT, THREE PATIENTS IN THE 16.7 MG/M(2) COHORT, THREE PATIENTS IN THE 24.6 MG/M(2) COHORT, FOUR PATIENTS IN THE 33 MG/M(2) COHORT, THREE PATIENTS IN THE 55 MG/M(2), AND SIX PATIENTS IN THE 83 MG/M(2) COHORT. PAIN AT THE INJECTION SITE, MOSTLY GRADE 1 AND GRADE 2, WAS THE MOST COMMON ADVERSE EVENT RELATED TO TREATMENT, EXPERIENCED BY 21 (84%) PATIENTS. OTHER COMMON DRUG-RELATED ADVERSE EVENTS INCLUDED ARM SWELLING OR OEDEMA (EIGHT [32%] PATIENTS), AND VEIN HARDENING (SEVEN [28%] PATIENTS). NO DOSE-LIMITING TOXICITIES WERE OBSERVED. TIME CONSTRAINTS RELATED TO MANAGEMENT OF INFUSION PAIN FROM RRX-001 RESULTED IN A MAXIMALLY FEASIBLE DOSE OF 83 MG/M(2). OF THE 21 EVALUABLE PATIENTS, ONE (5%) PATIENT HAD A PARTIAL RESPONSE, 14 (67%) PATIENTS HAD STABLE DISEASE, AND SIX (29%) PATIENTS HAD PROGRESSIVE DISEASE; ALL RESPONSES WERE ACROSS A VARIETY OF TUMOUR TYPES. FOUR PATIENTS WHO HAD RECEIVED RRX-001 WERE SUBSEQUENTLY RECHALLENGED WITH A TREATMENT THAT THEY HAD BECOME REFRACTORY TO; ALL FOUR RESPONDED TO THE RECHALLENGE. INTERPRETATION: RRX-001 IS A WELL-TOLERATED NOVEL COMPOUND WITHOUT CLINICALLY SIGNIFICANT TOXIC EFFECTS AT THE TESTED DOSES. PRELIMINARY EVIDENCE OF ACTIVITY IS PROMISING AND, ON THE BASIS OF ALL FINDINGS, A DOSE OF 16.7 MG/M(2) WAS RECOMMENDED AS THE TARGETED DOSE FOR PHASE 2 TRIALS. FUNDING: EPICENTRX (FORMERLY RADIORX). 2015 12 765 35 CC-486 MAINTENANCE AFTER STEM CELL TRANSPLANTATION IN PATIENTS WITH ACUTE MYELOID LEUKEMIA OR MYELODYSPLASTIC SYNDROMES. RELAPSE IS THE MAIN CAUSE OF TREATMENT FAILURE AFTER ALLOGENEIC STEM CELL TRANSPLANT (ALLOSCT) IN ACUTE MYELOID LEUKEMIA (AML) AND MYELODYSPLASTIC SYNDROMES (MDS). INJECTABLE AZACITIDINE CAN IMPROVE POST-TRANSPLANT OUTCOMES BUT PRESENTS CHALLENGES WITH EXPOSURE AND COMPLIANCE. ORAL CC-486 ALLOWS EXTENDED DOSING TO PROLONG AZACITIDINE ACTIVITY. WE INVESTIGATED USE OF CC-486 MAINTENANCE THERAPY AFTER ALLOSCT. ADULTS WITH MDS OR AML IN MORPHOLOGIC COMPLETE REMISSION AT CC-486 INITIATION (42 TO 84 DAYS AFTER ALLOSCT) WERE INCLUDED. PATIENTS RECEIVED 1 OF 4 CC-486 DOSING SCHEDULES PER 28-DAY CYCLE FOR UP TO 12 CYCLES. ENDPOINTS INCLUDED SAFETY, PHARMACOKINETICS, GRAFT-VERSUS-HOST DISEASE (GVHD) INCIDENCE, RELAPSE/PROGRESSION RATE, AND SURVIVAL. OF 30 PATIENTS, 7 RECEIVED CC-486 ONCE DAILY FOR 7 DAYS PER CYCLE (200 MG, N = 3; 300 MG, N = 4) AND 23 FOR 14 DAYS PER CYCLE (150 MG, N = 4; 200 MG, N = 19 [EXPANSION COHORT]). GRADES 3 TO 4 ADVERSE EVENTS WERE INFREQUENT AND OCCURRED WITH SIMILAR FREQUENCY ACROSS REGIMENS. STANDARD CONCOMITANT MEDICATIONS DID NOT ALTER CC-486 PHARMACOKINETIC PARAMETERS. THREE PATIENTS (10%) EXPERIENCED GRADE III ACUTE GVHD AND 9 EXPERIENCED CHRONIC GVHD. OF 28 EVALUABLE PATIENTS, 6 (21%) RELAPSED OR HAD PROGRESSIVE DISEASE: 3 OF 7 PATIENTS (43%) WHO HAD RECEIVED 7-DAY DOSING AND 3 OF 23 (13%) WHO HAD RECEIVED 14-DAY DOSING. TRANSPLANT-RELATED MORTALITY WAS 3%. AT 19 MONTHS OF FOLLOW-UP, MEDIAN OVERALL SURVIVAL WAS NOT REACHED. ESTIMATED 1-YEAR SURVIVAL RATES WERE 86% AND 81% IN THE 7-DAY AND 14-DAY DOSING COHORTS, RESPECTIVELY. CC-486 MAINTENANCE WAS GENERALLY WELL TOLERATED, WITH LOW RATES OF RELAPSE, DISEASE PROGRESSION, AND GVHD. CC-486 MAINTENANCE MAY PERMIT EPIGENETIC MANIPULATION OF THE ALLOREACTIVE RESPONSE POSTALLOGRAFT. FINDINGS REQUIRE CONFIRMATION IN RANDOMIZED TRIALS. (CLINICALTRIALS.GOV NCT01835587.). 2018 13 6460 24 TIME TO RELAPSE IN CHRONIC LYMPHOCYTIC LEUKEMIA AND DNA-METHYLATION-BASED BIOLOGICAL AGE. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS A MATURE B CELL NEOPLASM WITH A PREDILECTION FOR OLDER INDIVIDUALS. WHILE PREVIOUS STUDIES HAVE IDENTIFIED EPIGENETIC SIGNATURES ASSOCIATED WITH CLL, WHETHER AGE-RELATED DNA METHYLATION CHANGES MODULATE CLL RELAPSE REMAINS ELUSIVE. IN THIS STUDY, WE EXAMINED THE ASSOCIATION BETWEEN EPIGENETIC AGE ACCELERATION AND TIME TO CLL RELAPSE IN A PUBLICLY AVAILABLE DATASET. DNA METHYLATION PROFILING OF 35 CLL PATIENTS PRIOR TO INITIATING CHEMOIMMUNOTHERAPY WAS PERFORMED USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP. FOUR EPIGENETIC AGE ACCELERATION METRICS (INTRINSIC EPIGENETIC AGE ACCELERATION [IEAA], EXTRINSIC EPIGENETIC AGE ACCELERATION [EEAA], PHENOAGE ACCELERATION [PHENOAA], AND GRIMAGE ACCELERATION [GRIMAA]) WERE ESTIMATED FROM BLOOD DNA METHYLATION LEVELS. LINEAR, QUANTILE, AND LOGISTIC REGRESSION AND RECEIVER OPERATING CHARACTERISTIC CURVE ANALYSES WERE CONDUCTED TO ASSESS THE ASSOCIATION BETWEEN EACH EPIGENETIC AGE METRIC AND TIME TO CLL RELAPSE. EEAA (P = 0.011) AND PHENOAA (P = 0.046) WERE NEGATIVELY AND GRIMAA (P = 0.040) WAS POSITIVELY ASSOCIATED WITH TIME TO CLL RELAPSE. SIMULTANEOUS ASSESSMENT OF EEAA AND GRIMAA IN MALE PATIENTS DISTINGUISHED PATIENTS WHO RELAPSED EARLY FROM PATIENTS WHO RELAPSED LATER (P = 0.039). NO ASSOCIATIONS WERE OBSERVED WITH IEAA. THESE FINDINGS SUGGEST EPIGENETIC AGE ACCELERATION PRIOR TO CHEMOIMMUNOTHERAPY INITIATION IS ASSOCIATED WITH TIME TO CLL RELAPSE. OUR RESULTS PROVIDE NOVEL INSIGHT INTO THE ASSOCIATION BETWEEN AGE-RELATED DNA METHYLATION CHANGES AND CLL RELAPSE AND MAY SERVE HAS BIOMARKERS FOR TREATMENT RELAPSE, AND POTENTIALLY, TREATMENT SELECTION. 2023 14 2848 30 FREQUENT SOMATIC MUTATIONS IN EPIGENETIC REGULATORS IN NEWLY DIAGNOSED CHRONIC MYELOID LEUKEMIA. ALTHOUGH TYROSINE KINASE INHIBITORS (TKIS) HAVE SIGNIFICANTLY IMPROVED THE PROGNOSIS OF CHRONIC MYELOID LEUKEMIA (CML), THE ABILITY OF TKIS TO ERADICATE CML REMAINS UNCERTAIN AND PATIENTS MUST CONTINUE TKI THERAPY FOR INDEFINITE PERIODS. IN THIS STUDY, WE PERFORMED WHOLE-EXOME SEQUENCING TO IDENTIFY SOMATIC MUTATIONS IN 24 PATIENTS WITH NEWLY DIAGNOSED CHRONIC PHASE CML WHO WERE REGISTERED IN THE JALSG CML212 STUDY. WE IDENTIFIED 191 SOMATIC MUTATIONS OTHER THAN THE BCR-ABL1 FUSION GENE (MEDIAN 8, RANGE 1-17). AGE, HEMOGLOBIN CONCENTRATION AND WHITE BLOOD CELL COUNTS WERE CORRELATED WITH THE NUMBER OF MUTATIONS. PATIENTS WITH MUTATIONS ?6 SHOWED HIGHER RATE OF ACHIEVING MAJOR MOLECULAR RESPONSE THAN THOSE<6 (P=0.0381). MUTATIONS IN EPIGENETIC REGULATOR, ASXL1, TET2, TET3, KDM1A AND MSH6 WERE FOUND IN 25% OF PATIENTS. TET2 OR TET3, AKT1 AND RUNX1 WERE MUTATED IN ONE PATIENT EACH. ASXL1 WAS MUTATED WITHIN EXON 12 IN THREE CASES. MUTATED GENES WERE SIGNIFICANTLY ENRICHED WITH CELL SIGNALING AND CELL DIVISION PATHWAYS. FURTHERMORE, DNA COPY NUMBER ANALYSIS SHOWED THAT 2 OF 24 PATIENTS HAD UNIPARENTAL DISOMY OF CHROMOSOME 1P OR 3Q, WHICH DISAPPEARED MAJOR MOLECULAR RESPONSE WAS ACHIEVED. THESE MUTATIONS MAY PLAY SIGNIFICANT ROLES IN CML PATHOGENESIS IN ADDITION TO THE STRONG DRIVER MUTATION BCR-ABL1. 2017 15 536 30 ASXL1 MUTATIONS PREDICT INFERIOR MOLECULAR RESPONSE TO NILOTINIB TREATMENT IN CHRONIC MYELOID LEUKEMIA. GENE MUTATIONS INDEPENDENT OF BCR::ABL1 HAVE BEEN IDENTIFIED IN NEWLY DIAGNOSED PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) IN CHRONIC PHASE, WHEREBY MUTATIONS IN EPIGENETIC MODIFIER GENES WERE MOST COMMON. THESE FINDINGS PROMPTED THE SYSTEMATIC ANALYSIS OF PREVALENCE, DYNAMICS, AND PROGNOSTIC SIGNIFICANCE OF SUCH MUTATIONS, IN A CLINICALLY WELL-CHARACTERIZED PATIENT POPULATION OF 222 CML PATIENTS FROM THE TIGER STUDY (CML-V) BY TARGETED NEXT-GENERATION SEQUENCING COVERING 54 MYELOID LEUKEMIA-ASSOCIATED GENES. IN TOTAL, 53/222 CML PATIENTS (24%) CARRIED 60 MUTATIONS AT DIAGNOSIS WITH ASXL1 BEING MOST COMMONLY AFFECTED (N = 20). TO STUDY MUTATION DYNAMICS, LONGITUDINAL DEEP SEQUENCING ANALYSIS OF SERIAL SAMPLES WAS PERFORMED IN 100 PATIENTS AFTER 12, 24, AND 36 MONTHS OF THERAPY. TYPICAL PATTERNS OF CLONAL EVOLUTION INCLUDED ERADICATION, PERSISTENCE, AND EMERGENCE OF MUTATED CLONES. PATIENTS CARRYING AN ASXL1 MUTATION AT DIAGNOSIS SHOWED A LESS FAVORABLE MOLECULAR RESPONSE TO NILOTINIB TREATMENT, AS A MAJOR MOLECULAR RESPONSE (MMR) WAS ACHIEVED LESS FREQUENTLY AT MONTH 12, 18, AND 24 COMPARED TO ALL OTHER PATIENTS. PATIENTS WITH ASXL1 MUTATIONS WERE ALSO YOUNGER AND MORE FREQUENTLY FOUND IN THE HIGH RISK CATEGORY, SUGGESTING A CENTRAL ROLE OF CLONAL EVOLUTION ASSOCIATED WITH ASXL1 MUTATIONS IN CML PATHOGENESIS. 2022 16 5762 34 SOMATIC VARIANTS IN EPIGENETIC MODIFIERS CAN PREDICT FAILURE OF RESPONSE TO IMATINIB BUT NOT TO SECOND-GENERATION TYROSINE KINASE INHIBITORS. THERE ARE NO VALIDATED MOLECULAR BIOMARKERS TO IDENTIFY NEWLY-DIAGNOSED INDIVIDUALS WITH CHRONIC-PHASE CHRONIC MYELOID LEUKEMIA LIKELY TO RESPOND POORLY TO IMATINIB AND WHO MIGHT BENEFIT FROM FIRST-LINE TREATMENT WITH A MORE POTENT SECOND-GENERATION TYROSINE KINASE INHIBITOR. OUR INABILITY TO PREDICT THESE 'HIGH-RISK' INDIVIDUALS REFLECTS THE POORLY UNDERSTOOD HETEROGENEITY OF THE DISEASE. TO INVESTIGATE THE POTENTIAL OF GENETIC VARIANTS IN EPIGENETIC MODIFIERS AS BIOMARKERS AT DIAGNOSIS, WE USED ION TORRENT NEXT-GENERATION SEQUENCING OF 71 CANDIDATE GENES FOR PREDICTING RESPONSE TO TYROSINE KINASE INHIBITORS AND PROBABILITY OF DISEASE PROGRESSION. A TOTAL OF 124 SUBJECTS WITH NEWLY-DIAGNOSED CHRONIC-PHASE CHRONIC MYELOID LEUKEMIA BEGAN WITH IMATINIB (N=62) OR SECOND-GENERATION TYROSINE KINASE INHIBITORS (N=62) AND WERE CLASSIFIED AS RESPONDERS OR NON-RESPONDERS BASED ON THE BCRABL1 TRANSCRIPT LEVELS WITHIN THE FIRST YEAR AND THE EUROPEAN LEUKEMIANET CRITERIA FOR FAILURE. SOMATIC VARIANTS AFFECTING 21 GENES (E.G. ASXL1, IKZF1, DNMT3A, CREBBP) WERE DETECTED IN 30% OF SUBJECTS, MOST OF WHOM WERE NON-RESPONDERS (41% NON-RESPONDERS, 18% RESPONDERS TO IMATINIB, 38% NON-RESPONDERS, 25% RESPONDERS TO SECOND-GENERATION TYROSINE KINASE INHIBITORS). THE PRESENCE OF VARIANTS PREDICTED THE RATE OF ACHIEVING A MAJOR MOLECULAR RESPONSE, EVENT-FREE SURVIVAL, PROGRESSION-FREE SURVIVAL AND CHRONIC MYELOID LEUKEMIA-RELATED SURVIVAL IN THE IMATINIB BUT NOT THE SECOND-GENERATION TYROSINE KINASE INHIBITORS COHORT. RARE GERMLINE VARIANTS HAD NO PROGNOSTIC SIGNIFICANCE IRRESPECTIVE OF TREATMENT WHILE SOME PRE-LEUKEMIA VARIANTS SUGGEST A MULTI-STEP DEVELOPMENT OF CHRONIC MYELOID LEUKEMIA. OUR DATA SUGGEST THAT IDENTIFICATION OF SOMATIC VARIANTS AT DIAGNOSIS FACILITATES STRATIFICATION INTO IMATINIB RESPONDERS/NON-RESPONDERS, THEREBY ALLOWING EARLIER USE OF SECOND-GENERATION TYROSINE KINASE INHIBITORS, WHICH, IN TURN, MAY OVERCOME THE NEGATIVE IMPACT OF SUCH VARIANTS ON DISEASE PROGRESSION. 2019 17 5212 26 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 18 6574 31 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 19 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 20 4533 29 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