1 5984 158 TET2, DNMT3A, IDH1, AND JAK2 MUTATION IN MYELOPROLIFERATIVE NEOPLASMS IN SOUTHERN IRAN. BACKGROUND: FIVE EPIGENETIC REGULATOR MUTATIONS ARE CONSIDERED IN MYELOPROLIFERATIVE NEOPLASMS (MPN) THAT HAVE PROGNOSTIC AND THERAPEUTIC VALUES. OBJECTIVE: WE AIMED TO EVALUATE THESE MUTATIONS IN MPNS AMONG THE IRANIAN POPULATION. METHODS: WE SELECTED 5 MUTATIONS IN 4 EPIGENETIC REGULATORY GENES [TET2, DNMT3A, IDH1 (RS147001633&RS121913499), AND JAK2)] AND EVALUATED 130 PATIENTS WITH MPNS INCLUDING 78 PHILADELPHIA CHROMOSOME NEGATIVE (49 ETS, 20 PVS, AND 9 PMFS) AND 52 PHILADELPHIA CHROMOSOME-POSITIVE PATIENTS AS WELL AS 51 HEALTHY CONTROLS. RESULTS: EIGHT PATIENTS (6.5%) CARRIED THE DNMT3A MUTATION, 35 (27%) WERE POSITIVE FOR TET2 MUTATION AND 64 (49.3%) HAD THE JAK2V617F MUTATION. IN THE HEALTHY CONTROLS, 16 (31.4%) CASES HAD THE TET2 MUTATION (15 HETEROZYGOTE + 1 HOMOZYGOTE) AND ONE HAD HETEROZYGOTE JAK2 MUTATION. THERE WAS NO STATISTICALLY SIGNIFICANT DIFFERENCE BETWEEN PATIENT GROUPS FOR ANY OF THESE MUTATIONS, EXCEPT FOR JAK2. THE JAK2 MUTATION RATE WAS 18 (90%), 25 (51%), 7 (77.8%), 14 (26.9%) IN POLYCYTHEMIA VERA, ESSENTIAL THROMBOCYTHEMIA, PRIMARY MYELOFIBROSIS, AND CHRONIC MYELOCYTIC LEUKEMIA, RESPECTIVELY. PATIENTS AGED 60 AND OLDER WERE MORE LIKELY TO CARRY THE TET2 MUTATION (23% VS. 39% IN YOUNGER AND OLDER THAN 60 YEARS OLD INDIVIDUALS, P=0.025). IDH1 WAS NOT DETECTED AT ALL AND PV HAD THE HIGHEST TET2 MUTATION 7(35%). TWO PMF PATIENTS HAD A HISTORY OF BONE MARROW TRANSPLANTATION THAT WERE NEGATIVE FOR IDH1AND DNMT3A AND ONE WAS POSITIVE FOR TET2 MUTATION. CONCLUSION: IN THE NORMAL IRANIAN POPULATION, THE HETEROZYGOTE FORM OF TET2 MUTATION IS SIGNIFICANT, ESPECIALLY IN THE ELDERLY. NO ASSOCIATION WAS FOUND BETWEEN JAK2 AND TET2 MUTATIONS. BOTH OF THEM ARE MORE PREVALENT IN THE AGE GROUP OF 60 YEARS AND OLDER. DNMT3A MUTATION HAS A LOW PREVALENCE AND OCCURS IN BOTH POSITIVE AND NEGATIVE MPNS. 2021 2 1100 43 COMBINATION OF MYELOPROLIFERATIVE NEOPLASM DRIVER GENE ACTIVATION WITH MUTATIONS OF SPLICE FACTOR OR EPIGENETIC MODIFIER GENES INCREASES RISK OF RAPID BLASTIC PROGRESSION. OBJECTIVES: MYELOPROLIFERATIVE NEOPLASMS (MPN) COMPRISING POLYCYTHEMIA VERA (PV), ESSENTIAL THROMBOCYTHEMIA (ET) AND PRIMARY MYELOFIBROSIS (PMF) FOLLOW A BI-PHASIC COURSE OF DISEASE WITH FIBROTIC AND/OR BLASTIC PROGRESSION. AT PRESENTATION IN THE CHRONIC PHASE, CURRENTLY THERE ARE ONLY INSUFFICIENT TOOLS TO PREDICT THE RISK OF PROGRESSION IN INDIVIDUAL CASES. METHODS: IN THIS STUDY, CHRONIC PHASE MPN (16 PMF, 11 PV, AND 11 MPN UNCLASSIFIED) WITH BLASTIC TRANSFORMATION DURING COURSE OF DISEASE (N = 38, MEDIAN FOLLOW-UP 5.3 YEARS) WERE ANALYZED BY HIGH-THROUGHPUT SEQUENCING. MPN CASES WITH A COMPARABLE FOLLOW-UP PERIOD AND WITHOUT EVIDENCE OF BLAST INCREASE SERVED AS CONTROL (N = 63, MEDIAN FOLLOW-UP 5.8 YEARS). RESULTS: FREQUENT ARCH/CHIP-ASSOCIATED MUTATIONS (TET2, ASXL1, DNMT3A) FOUND AT PRESENTATION WERE NOT SIGNIFICANTLY ASSOCIATED WITH BLASTIC TRANSFORMATION. BY CONTRAST, MUTATIONS OF SRSF2, U2AF1, AND IDH1/2 AT FIRST PRESENTATION WERE FREQUENTLY OBSERVED IN THE PROGRESSION COHORT (13/38, 34.2%) AND WERE COMPLETELY MISSING IN THE CONTROL GROUP WITHOUT BLAST TRANSFORMATION DURING FOLLOW-UP (P = .0007 FOR SRSF2; P = .0063 FOR U2AF1 AND IDH1/2). CONCLUSION: UNLIKE FREQUENT ARCH/CHIP ALTERATIONS (TET2, ASXL1, DNMT3A), MUTATIONS IN SRSF2, IDH1/2, AND U2AF1 WHEN MANIFEST ALREADY AT FIRST PRESENTATION PROVIDE AN INDEPENDENT RISK FACTOR FOR RAPID BLAST TRANSFORMATION OF MPN. 2021 3 5665 33 SF3B1, RUNX1 AND TP53 MUTATIONS SIGNIFICANTLY IMPACT THE OUTCOME OF PATIENTS WITH LOWER-RISK MYELODYSPLASTIC SYNDROME. INTRODUCTION: PROGNOSIS OF PATIENTS WITH MYELODYSPLASTIC SYNDROME (MDS), PARTICULARLY THE GROUP WITH LOWER-RISK DISEASE (LR-MDS) IS VERY HETEROGENEOUS. SEVERAL STUDIES HAVE DESCRIBED THE PROGNOSTIC VALUE OF RECURRENT SOMATIC MUTATIONS IN MDS INCLUDING ALL RISK CATEGORIES. RECENTLY, THE INCORPORATION OF GENOMIC DATA TO CLINICAL PARAMETERS DEFINED THE NEW MOLECULAR INTERNATIONAL PROGNOSTIC SCORING SYSTEM (IPSS-M). MATERIALS AND METHODS: IN THIS STUDY, WE EVALUATED THE IMPACT OF MOLECULAR PROFILE IN A SERIES OF 181 PATIENTS WITH LR-MDS AND NON-PROLIFERATIVE CHRONIC MYELOMONOCYTIC LEUKEMIA. RESULTS: EPIGENETIC REGULATORS (TET2, ASXL1) AND SPLICING (SF3B1) WERE THE MOST RECURRENT MUTATED PATHWAYS. IN UNIVARIATE ANALYSIS, RUNX1 OR TP53 MUTATIONS CORRELATED WITH LOWER MEDIAN OVERALL SURVIVAL (OS). IN CONTRAST, SF3B1 MUTATION WAS ASSOCIATED WITH PROLONGED MEDIAN OS [95 MONTHS (95% IC, 32-157) VS. 33 MONTHS (95% CI, 19-46) IN UNMUTATED PATIENTS (P < 0.01)]. IN A MULTIVARIATE COX REGRESSION MODEL, RUNX1 MUTATIONS INDEPENDENTLY ASSOCIATED WITH SHORTER OS, WHILE SF3B1 MUTATION RETAINED ITS FAVORABLE IMPACT ON OUTCOME (HR: 0.24, 95% CI, 0.1-0.5; P = 0.001). IN ADDITION, TP53 OR RUNX1 MUTATIONS WERE IDENTIFIED AS PREDICTIVE COVARIATES FOR THE PROBABILITY OF LEUKEMIC PROGRESSION (P < 0.001). CONCLUSION: INCORPORATION OF MOLECULAR TESTING IN LR-MDS IDENTIFIED A SUBSET OF PATIENTS WITH EXPECTED POORER OUTCOME, EITHER DUE TO LOWER SURVIVAL OR PROBABILITY OF LEUKEMIC PROGRESSION. 2022 4 2088 42 EPIGENETIC DYSREGULATION OF SECRETED FRIZZLED-RELATED PROTEINS IN MYELOPROLIFERATIVE NEOPLASMS COMPLEMENTS THE JAK2V617F-MUTATION. BACKGROUND: SECRETED FRIZZLED-RELATED PROTEINS (SFRPS) ARE ANTAGONISTS OF THE WNT SIGNALING PATHWAY, WHICH PLAYS A CENTRAL ROLE IN STEM CELL MAINTENANCE AND DIFFERENTIATION OF STEM CELLS AND HEMATOPOIETIC PROGENITORS. EPIGENETIC DOWNREGULATION OF SFRPS BY PROMOTER HYPERMETHYLATION HAS BEEN DESCRIBED TO BE INVOLVED IN THE PATHOGENESIS OF HEMATOPOIETIC MALIGNANCIES. THERE IS AN ASSOCIATION BETWEEN ABERRANT WNT SIGNALING AND THE ESTABLISHED CANCER STEM CELL CONCEPT. IN CONTRAST TO BCR-ABL1-POSITIVE CHRONIC MYELOID LEUKEMIA CML, BCR-ABL1-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS (PH-MPN) ARE CHARACTERIZED BY THE FREQUENT OCCURRENCE OF AN AUTOACTIVATING MUTATION IN THE JAK2 TYROSINE KINASE (JAK2V617F) OR OTHER MUTATIONS IN THE JAK-STAT PATHWAY. HOWEVER, PATHOGENETIC MECHANISMS OF JAK2 MUTATED OR UNMUTATED PH-MPN REMAIN NOT COMPLETELY UNDERSTOOD. WE DETERMINED THE PROMOTER METHYLATION STATUS OF SFRP-1, -2, -4, AND -5 IN 57 MPN PATIENT SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) (MSP). JAK2V617F WAS ASSESSED BY ALLELE-SPECIFIC PCR. RESULTS: ABERRANT METHYLATION AMONG PRIMARY MPN SAMPLES WAS 4% FOR SFRP-1, 25% FOR SFRP-2, 2% FOR SFRP-4, AND 0% FOR SFRP-5. HYPERMETHYLATION OF SFRP-2, WHICH WAS THE MOST FREQUENTLY HYPERMETHYLATED GENE IN OUR STUDY, COULD NOT BE CORRELATED TO ANY SPECIFIC MPN SUBTYPE. HOWEVER, WE DETECTED A SIGNIFICANT CORRELATION BETWEEN SFRP-2 METHYLATION AND PRESENCE OF A JAK2V617F MUTATION (P = 0.008). NONE OF THE 10 CML SAMPLES SHOWED ANY SFRP-METHYLATION. CONCLUSIONS: OUR DATA INDICATE THAT EPIGENETIC DYSREGULATION OF THE WNT SIGNALING PATHWAY IS A COMMON EVENT IN MPN WITH ABERRANT METHYLATION OF AT LEAST ONE SFRP BEING DETECTED IN 25% OF THE PRIMARY PATIENT SAMPLES AND IN 30% IF ONLY ACCOUNTING FOR PH-MPN. A SIGNIFICANT CORRELATION BETWEEN SFRP-2 METHYLATION AND PRESENCE OF JAK2V617F IN OUR DATA SUPPORTS THE HYPOTHESIS THAT EPIGENETIC DYSREGULATION MAY BE A COMPLEMENTARY MECHANISM TO GENETIC ABERRATIONS. ABERRANT METHYLATION OF CRUCIAL STEM CELL MAINTENANCE GENES SEEMS TO CONTRIBUTE TO DISEASE PATHOGENESIS IN PH-MPN. 2012 5 4571 32 MYELOMONOCYTIC SKEWING IN CHRONIC MYELOMONOCYTIC LEUKEMIA: PHENOTYPIC, MOLECULAR AND BIOLOGIC FEATURES AND IMPACT ON SURVIVAL. BACKGROUND: MYELOMONOCYTIC SKEWING IS CONSIDERED AS A KEY PATHOPHYSIOLOGIC PHENOMENON IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), BUT ITS PREVALENCE AND POTENTIAL CORRELATION WITH PHENOTYPIC, GENOTYPIC, AND CLINICAL FEATURES ARE POORLY DEFINED. METHODS: SKEWED DIFFERENTIATION TOWARD THE MYELOMONOCYTIC OVER ERYTHROID COMMITMENT AS INDICATED BY AN INVERSE RATIO OF MYELOMONOCYTIC/ERYTHROID COLONIES WAS INVESTIGATED IN 146 PATIENTS WITH CMML BY SEMISOLID IN VITRO CULTURES. RESULTS: THERE WAS A HIGH PREVALENCE OF MYELOMONOCYTIC SKEWING IN PATIENTS WITH CMML (120/146, 82%); WHEREAS, THIS PHENOMENON WAS RARE IN NORMAL INDIVIDUALS (1/98, 1%). PATIENTS WITH CMML WITH MYELOMONOCYTIC SKEWING HAD HIGHER WHITE BLOOD CELL AND PERIPHERAL BLAST CELL COUNTS, AND LOWER PLATELET VALUES. THE NUMBER OF MUTATIONS IN GENES OF THE EPIGENETIC AND/OR SPLICING CATEGORY WAS HIGHER IN CMML PATIENTS WITH AS COMPARED WITH PATIENTS WITHOUT SKEWING. PATIENTS WITH MYELOMONOCYTIC SKEWING HAD MORE FREQUENTLY MUTATIONS IN RASOPATHY GENES AND HIGHER GROWTH FACTOR INDEPENDENT MYELOID COLONY FORMATION. INTERESTINGLY, THE LACK OF MYELOMONOCYTIC SKEWING DISCRIMINATED PATIENTS WITH CMML WITH A PARTICULARLY FAVORABLE PROGNOSIS (60 VS 19 MONTHS, P = .003) AND A MINIMAL RISK OF TRANSFORMATION. CONCLUSION: MYELOMONOCYTIC SKEWING AS DETERMINED BY SEMISOLID CULTURES CAN DISCRIMINATE SUBGROUPS OF PATIENTS WITH CMML WITH A DIFFERENT PHENOTYPE, A DIFFERENT GENOTYPE, AND A DIFFERENT PROGNOSIS. 2021 6 4555 42 MUTATIONAL SPECTRUM ANALYSIS OF CHRONIC MYELOMONOCYTIC LEUKEMIA INCLUDES GENES ASSOCIATED WITH EPIGENETIC REGULATION: UTX, EZH2, AND DNMT3A. CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML), A MYELODYSPLASTIC/MYELOPROLIFERATIVE NEOPLASM, IS CHARACTERIZED BY MONOCYTIC PROLIFERATION, DYSPLASIA, AND PROGRESSION TO ACUTE MYELOID LEUKEMIA. CMML HAS BEEN ASSOCIATED WITH SOMATIC MUTATIONS IN DIVERSE RECENTLY IDENTIFIED GENES. WE ANALYZED 72 WELL-CHARACTERIZED PATIENTS WITH CMML (N = 52) AND CMML-DERIVED ACUTE MYELOID LEUKEMIA (N = 20) FOR RECURRENT CHROMOSOMAL ABNORMALITIES WITH THE USE OF ROUTINE CYTOGENETICS AND SINGLE NUCLEOTIDE POLYMORPHISM ARRAYS ALONG WITH COMPREHENSIVE MUTATIONAL SCREENING. CYTOGENETIC ABERRATIONS WERE PRESENT IN 46% OF CASES, WHEREAS SINGLE NUCLEOTIDE POLYMORPHISM ARRAY INCREASED THE DIAGNOSTIC YIELD TO 60%. AT LEAST 1 MUTATION WAS FOUND IN 86% OF ALL CASES; NOVEL UTX, DNMT3A, AND EZH2 MUTATIONS WERE FOUND IN 8%, 10%, AND 5.5% OF PATIENTS, RESPECTIVELY. TET2 MUTATIONS WERE PRESENT IN 49%, ASXL1 IN 43%, CBL IN 14%, IDH1/2 IN 4%, KRAS IN 7%, NRAS IN 4%, AND JAK2 V617F IN 1% OF PATIENTS. VARIOUS MUTANT GENOTYPE COMBINATIONS WERE OBSERVED, INDICATING MOLECULAR HETEROGENEITY IN CMML. OUR RESULTS SUGGEST THAT MOLECULAR DEFECTS AFFECTING DISTINCT PATHWAYS CAN LEAD TO SIMILAR CLINICAL PHENOTYPES. 2011 7 4540 38 MULTISTEP PATHOGENESIS OF CHRONIC MYELOMONOCYTIC LEUKEMIA IN PATIENTS. BACKGROUND: A MULTISTEP PATHOGENESIS OF MYELOID LEUKEMIA INCLUDING MUTATIONS IN EPIGENETIC, SPLICEOSOME, AND SIGNALING GENES HAS BEEN RECENTLY DEMONSTRATED IN A PRECLINICAL MODEL BUT IS POORLY VALIDATED IN PATIENTS. METHODS: CLINICAL, PHENOTYPIC, AND BIOLOGIC FEATURES WERE COMPARED BETWEEN THREE DISTINCT MOLECULARLY DEFINED CMML COHORTS INCLUDING TET2 MONOMUTATED PATIENTS (T, N = 10), TET2/SRSF2 BIMUTATED PATIENTS (TS, N = 19), AND PATIENTS WHO HAD NRAS MUTATIONS IN ADDITION TO TET2/SRSF2 COMUTATIONS (TSN, N = 14). RESULTS: MEDIAN SURVIVAL WAS 90, 45, AND 9 MONTHS, RESPECTIVELY (P = .001). WHEREAS NO PATIENT IN THE T AND TS GROUP TRANSFORMED INTO ACUTE MYELOID LEUKEMIA (AML), 6/14 PATIENTS IN THE TSN GROUP HAD AML AT STUDY ENTRY OR TRANSFORMED DURING FOLLOW-UP. LEUKOCYTE COUNTS, BLAST CELL COUNTS, AND LDH LEVELS WERE SIGNIFICANTLY HIGHER IN TSN VS. TS AND T, RESPECTIVELY, WHEREAS HEMOGLOBIN AND PLATELET VALUES WERE NOT SIGNIFICANTLY DIFFERENT. INCREASED GROWTH FACTOR-INDEPENDENT MYELOID COLONY FORMATION WAS RESTRICTED TO TSN BUT NOT FOUND IN T AND TS, RESPECTIVELY. THE PROPORTION OF PATIENTS SHOWING IN VITRO MYELOMONOCYTIC SKEWING IN T, TS, AND TSN WAS 0%, 56%, AND 100%, RESPECTIVELY (P = .010). CONCLUSION: OUR RESULTS DEMONSTRATE THAT THE MODEL OF MULTISTEP PATHOGENESIS IN CMML CAN BE RECAPITULATED IN PATIENTS REGARDING CLINICAL, PHENOTYPIC, AND BIOLOGIC FEATURES. 2022 8 536 33 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 9 4549 31 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 10 831 41 CHARACTERIZATION OF TET AND IDH GENE EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA: COMPARISON WITH NORMAL B CELLS AND PROGNOSTIC SIGNIFICANCE. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON HEMATOLOGICAL MALIGNANCY IN WESTERN COUNTRIES, CHARACTERIZED BY A HETEROGENEOUS CLINICAL COURSE. ALTHOUGH GENETIC STUDIES HAVE IDENTIFIED CHROMOSOMAL ABERRATIONS OR SPECIFIC MUTATIONS, EPIGENETIC CHANGES HAVE BEEN POORLY CHARACTERIZED IN CLL. METHODS: WE ASSESSED TEN-ELEVEN TRANSLOCATIONS (TET) 1, 2, AND 3, ISOCITRATE DEHYDROGENASE (IDH) 1, AND 2 MESSENGER RNA (MRNA) EXPRESSION USING REAL-TIME PCR ON PURIFIED LEUKEMIC B CELLS FROM 214 CLL PATIENTS (MEDIAN FOLLOW-UP = 75 MONTHS, RANGE 1-380), NORMAL PERIPHERAL BLOOD B CELLS (N = 20), AND UMBILICAL CORD BLOOD B CELLS (N = 21). THE MICROENVIRONMENT INFLUENCE WAS ASSESSED AFTER 24 H CO-CULTURE OF CLL CELLS WITH BONE MARROW MESENCHYMAL STROMAL CELLS (BMSC). FINALLY, 5-HYDROXYMETHYLCYTOSINE LEVEL (%5-HMC) WAS ASSESSED BY ELISA IN CLL CELLS ALONE OR WITH MICROENVIRONMENT STIMULI. RESULTS: TET 1 AND 3 AND IDH2 WERE DECREASED IN CLL CELLS COMPARED WITH HEALTHY B CELLS (P = 0.0221, 0.0013, <0.0001, RESPECTIVELY), WHILE IDH1 WAS OVEREXPRESSED (P = 0.0037). TET2 AND IDH1 WERE SIGNIFICANTLY CORRELATED WITH TREATMENT-FREE SURVIVAL (TFS); PATIENTS WITH HIGH TET2/IDH1 EXPRESSION HAD A HIGHER MEDIAN TFS (111 MONTHS) THAN PATIENTS WITH LOW EXPRESSION (78 MONTHS, P = 0.0071/0.0123). MOREOVER, TET1 EXPRESSION DECREASED (P = 0.0371), WHILE TET3 AND IDH2 EXPRESSION INCREASED (P = 0.0273/0.0039) IN CO-CULTURES. HOWEVER, %5-HMC WAS NOT CORRELATED WITH CLINICAL DATA AND WAS UNCHANGED FOLLOWING MICROENVIRONMENT STIMULI. CONCLUSIONS: DESPITE A SLIGHT DEREGULATION IN CLL CELLS COMPARED WITH NORMAL B CELLS, WE IDENTIFIED A SIGNIFICANT ASSOCIATION BETWEEN TET/IDH GENE EXPRESSION AND PROGNOSIS, SUGGESTING THAT EPIGENETIC CHANGES COULD POTENTIALLY BE ASSOCIATED WITH DISEASE PROGRESSION. MOREOVER, DESPITE AN IDENTICAL %5-HMC, TET GENE EXPRESSION WAS INFLUENCED BY CONTACT WITH BMSC CONFIRMING THE CRUCIAL ROLE OF THE MICROENVIRONMENT IN CLL PATHOGENESIS. 2016 11 472 42 ARRAY COMPARATIVE GENOMIC HYBRIDIZATION AND SEQUENCING OF 23 GENES IN 80 PATIENTS WITH MYELOFIBROSIS AT CHRONIC OR ACUTE PHASE. MYELOFIBROSIS IS A MYELOPROLIFERATIVE NEOPLASM THAT OCCURS DE NOVO (PRIMARY MYELOFIBROSIS) OR RESULTS FROM THE PROGRESSION OF POLYCYTHEMIA VERA OR ESSENTIAL THROMBOCYTEMIA (HEREAFTER DESIGNATED AS SECONDARY MYELOFIBROSIS OR POST-POLYCYTHEMIA VERA/ ESSENTIAL THROMBOCYTHEMIA MYELOFIBROSIS). TO PROGRESS IN THE UNDERSTANDING OF MYELOFIBROSIS AND TO FIND MOLECULAR PROGNOSTIC MARKERS WE STUDIED 104 SAMPLES OF PRIMARY AND SECONDARY MYELOFIBROSIS AT CHRONIC (N=68) AND ACUTE PHASES (N=12) FROM 80 PATIENTS, BY USING ARRAY-COMPARATIVE GENOMIC HYBRIDIZATION AND SEQUENCING OF 23 GENES (ASXL1, BMI1, CBL, DNMT3A, EZH2, IDH1/2, JAK2, K/NRAS, LNK, MPL, NF1, PPP1R16B, PTPN11, RCOR1, SF3B1, SOCS2, SRSF2, SUZ12, TET2, TP53, TRPS1). WE FOUND COPY NUMBER ABERRATIONS IN 54% OF SAMPLES, OFTEN INVOLVING GENES WITH A KNOWN OR POTENTIAL ROLE IN LEUKEMOGENESIS. WE SHOW THAT CASES CARRYING A DEL(20Q), DEL(17) OR DEL(12P) EVOLVE IN ACUTE MYELOID LEUKEMIA (P=0.03). WE FOUND THAT 88% OF THE CASES WERE MUTATED, MAINLY IN SIGNALING PATHWAY (JAK2 69%, NF1 6%) AND EPIGENETIC GENES (ASXL1 26%, TET2 14%, EZH2 8%). OVERALL SURVIVAL WAS POOR IN PATIENTS WITH MORE THAN ONE MUTATION (P=0.001) AND IN PATIENTS WITH JAK2/ASXL1 MUTATIONS (P=0.02). OUR STUDY HIGHLIGHTS THE HETEROGENEITY OF MYELOFIBROSIS, AND POINTS TO SEVERAL INTERESTING COPY NUMBER ABERRATIONS AND GENES WITH DIAGNOSTIC AND PROGNOSTIC IMPACT. 2014 12 409 38 ANALYSIS OF GENES ENCODING EPIGENETIC REGULATORS IN MYELOPROLIFERATIVE NEOPLASMS: COEXISTENCE OF A NOVEL SETBP1 MUTATION IN A PATIENT WITH A P.V617F JAK2 POSITIVE MYELOFIBROSIS. IN RECENT YEARS IT HAS BEEN SHOWN THAT THE CAUSES OF CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE MORE COMPLEX THAN A SIMPLE SIGNALING ABERRATION AND MANY OTHER MUTATED GENES AFFECTING DIFFERENT CELL PROCESSES HAVE BEEN DESCRIBED. FOR INSTANCE, MUTATIONS IN GENES ENCODING EPIGENETIC REGULATORS ARE MORE FREQUENT THAN EXPECTED. ONE OF THE LATEST GENES DESCRIBED AS MUTATED IS SET BINDING PROTEIN 1 (SETBP1). IN SILICO TOOLS HAVE REVEALED THAT THERE ARE SEVERAL HUMAN SETBP1 PARALOGOUS TO NUCLEAR RECEPTOR BINDING SET DOMAIN PROTEIN 1 (NSD1), NSD2 AND NSD3, FOR EXAMPLE, WHICH ARE ALSO INVOLVED IN THE DEVELOPMENT OF OTHER HEMATOLOGICAL MALIGNANCIES. THEREFORE, THE PRESENT STUDY ANALYZED THE MUTATIONAL STATUS OF NSD1, NSD2, NSD3 AND SETBP1 IN BCR-ABL1 NEGATIVE MPNS WITH OR WITHOUT JANUS KINASE 2 (JAK2) P.V617F MUTATION. THE PRESENT STUDY REVEALED THAT THE NSD GENES ARE NOT FREQUENTLY MUTATED IN MPNS. HOWEVER, A NOVEL SETBP1 MUTATION WAS IDENTIFIED IN A PATIENT WITH P.V617F JAK2 POSITIVE PRIMARY MYELOFIBROSIS. THESE RESULTS PROVIDE FURTHER INSIGHT INTO THE GENETIC COMPLEXITY OF MPNS. 2019 13 3560 32 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 14 2911 48 GENE EXPRESSION PROFILING OF LOSS OF TET2 AND/OR JAK2V617F MUTANT HEMATOPOIETIC STEM CELLS FROM MOUSE MODELS OF MYELOPROLIFERATIVE NEOPLASMS. MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE CLINICALLY CHARACTERIZED BY THE CHRONIC OVERPRODUCTION OF DIFFERENTIATED PERIPHERAL BLOOD CELLS AND THE GRADUAL EXPANSION OF MALIGNANT INTRAMEDULLARY/EXTRAMEDULLARY HEMATOPOIESIS. IN MPNS MUTATIONS IN JAK2 MPL OR CALR ARE DETECTED MUTUALLY EXCLUSIVE IN MORE THAN 90% OF CASES [1,2]. MUTATIONS IN THEM LEAD TO THE ABNORMAL ACTIVATION OF JAK/STAT SIGNALING AND THE AUTONOMOUS GROWTH OF DIFFERENTIATED CELLS THEREFORE THEY ARE CONSIDERED AS "DRIVER" GENE MUTATIONS. IN ADDITION TO THE ABOVE DRIVER GENE MUTATIONS MUTATIONS IN EPIGENETIC REGULATORS SUCH AS TET2 DNMT3A ASXL1 EZH2 OR IDH1/2 ARE DETECTED IN ABOUT 5%-30% OF CASES RESPECTIVELY [3]. MUTATIONS IN TET2 DNMT3A EZH2 OR IDH1/2 COMMONLY CONFER THE INCREASED SELF-RENEWAL CAPACITY ON NORMAL HEMATOPOIETIC STEM CELLS (HSCS) BUT THEY DO NOT LEAD TO THE AUTONOMOUS GROWTH OF DIFFERENTIATED CELLS AND ONLY EXHIBIT SUBTLE CLINICAL PHENOTYPES [4,6-8,5]. IT WAS UNCLEAR HOW MUTATIONS IN SUCH EPIGENETIC REGULATORS INFLUENCED ABNORMAL HSCS WITH DRIVER GENE MUTATIONS HOW THEY INFLUENCED THE DISEASE PHENOTYPE OR WHETHER A SINGLE DRIVER GENE MUTATION WAS SUFFICIENT FOR THE INITIATION OF HUMAN MPNS. THEREFORE WE FOCUSED ON JAK2V617F AND LOSS OF TET2-THE FORMER AS A REPRESENTATIVE OF DRIVER GENE MUTATIONS AND THE LATTER AS A REPRESENTATIVE OF MUTATIONS IN EPIGENETIC REGULATORS-AND EXAMINED THE INFLUENCE OF SINGLE OR DOUBLE MUTATIONS ON HSCS (LINEAGE(-)SCA-1(+)C-KIT(+) CELLS (LSKS)) BY FUNCTIONAL ANALYSES AND MICROARRAY WHOLE-GENOME EXPRESSION ANALYSES [9]. GENE EXPRESSION PROFILING SHOWED THAT THE HSC FINGERPRINT GENES [10] WAS STATISTICALLY EQUALLY ENRICHED IN TET2-KNOCKDOWN-LSKS BUT NEGATIVELY ENRICHED IN JAK2V617F-LSKS COMPARED TO THAT IN WILD-TYPE-LSKS. DOUBLE-MUTANT-LSKS SHOWED THE SAME TENDENCY AS JAK2V617F-LSKS IN TERMS OF THEIR HSC FINGERPRINT GENES BUT THE EXPRESSION OF INDIVIDUAL GENES DIFFERED BETWEEN THE TWO GROUPS. AMONG 245 HSC FINGERPRINT GENES 100 WERE MORE HIGHLY EXPRESSED IN DOUBLE-MUTANT-LSKS THAN IN JAK2V617F-LSKS. THESE ALTERED GENE EXPRESSIONS MIGHT PARTLY EXPLAIN THE MECHANISMS OF INITIATION AND PROGRESSION OF MPNS WHICH WAS OBSERVED IN THE FUNCTIONAL ANALYSES [9]. HERE WE DESCRIBE GENE EXPRESSION PROFILES DEPOSITED AT THE GENE EXPRESSION OMNIBUS (GEO) UNDER THE ACCESSION NUMBER GSE62302 INCLUDING EXPERIMENTAL METHODS AND QUALITY CONTROL ANALYSES. 2015 15 4554 37 MUTATIONAL PROFILING IN MYELOFIBROSIS: IMPLICATIONS FOR MANAGEMENT. MUTATIONAL PROFILING, USUALLY BY TARGETED NEXT-GENERATION SEQUENCING, IS INCREASINGLY PERFORMED ON PATIENTS WITH MYELOPROLIFERATIVE NEOPLASM-ASSOCIATED MYELOFIBROSIS (MF), WHETHER PRIMARY (PMF) OR POST-POLYCYTHEMIA VERA/ESSENTIAL THROMBOCYTHEMIA (POST-PV/ET MF). "DRIVER" MUTATIONS IN JAK2, MPL AND INDELS IN CALR UNDERLIE THE VAST MAJORITY OF CASES OF PMF AND POST-ET MF; THE REMAINDER ( APPROXIMATELY 10%) LACK IDENTIFIABLE DRIVER MUTATIONS, BUT OTHER CLONAL MARKERS ARE USUALLY DETECTABLE. NEARLY ALL PATIENTS WITH POST-PV MF CARRY ACTIVATING JAK2 MUTATIONS. IN BOTH PMF AND POST-ET MF, TYPE 1/-LIKE CALR MUTATIONS CONFER A FAVORABLE PROGNOSIS. SINCE BOTH TYPE 1/-LIKE AND TYPE 2/-LIKE CALR MUTATIONS HAVE ESSENTIALLY THE SAME FUNCTIONAL CONSEQUENCE, THIS IS A SUBJECT OF INTENSE RESEARCH. ADDITIONAL, "NON-DRIVER" MUTATIONS, MOSTLY AFFECTING GENES ENCODING EPIGENETIC MODIFIERS OR SPLICEOSOME COMPONENTS, E.G., ASXL1, EZH2, TET2, DNMT3A, SRSF2 AND U2AF1, ARE FREQUENTLY FOUND; SOME OF THESE ARE ASSOCIATED WITH INFERIOR SURVIVAL AND HAVE BEEN INCORPORATED INTO PROGNOSTIC MODELS. SOME MUTATIONS, E.G., IDH1/2, ARE RELATIVELY INFREQUENT IN CHRONIC PHASE BUT ARE SUBSTANTIALLY MORE COMMON IN BLAST PHASE, AND ARE NOW THERAPEUTICALLY TARGETABLE. WHILE MUTATIONAL INFORMATION DOES NOT CURRENTLY INFLUENCE CHOICE OF DRUG THERAPY IN CHRONIC-PHASE MF, THE PRESENCE OF A "HIGH MOLECULAR RISK" GENOTYPE IS NOW ROUTINELY TAKEN INTO ACCOUNT FOR TRANSPLANT DECISION-MAKING. 2020 16 1043 41 CLINICAL CHARACTERISTICS AND WHOLE EXOME/TRANSCRIPTOME SEQUENCING OF COEXISTING CHRONIC MYELOID LEUKEMIA AND MYELOFIBROSIS. MYELOPROLIFERATIVE NEOPLASMS (MPNS) ARE CLONAL HEMATOPOIETIC STEM CELL (HSC) DISORDERS THAT CAN BE CLASSIFIED ON THE BASIS OF GENETIC, CLINICAL, PHENOTYPIC FEATURES. GENETIC LESIONS SUCH AS JAK2 MUTATIONS AND BCR-ABL TRANSLOCATION ARE OFTEN MUTUALLY EXCLUSIVE IN MPN PATIENTS AND LEAD TO ESSENTIAL THROMBOCYTHEMIA, POLYCYTHEMIA VERA, OR MYELOFIBROSIS OR CHRONIC MYELOID LEUKEMIA, RESPECTIVELY. NEVERTHELESS, COEXISTENCE OF THESE GENETIC ABERRATIONS IN THE SAME PATIENT HAS BEEN REPORTED. WHETHER THESE ABERRATIONS OCCUR IN THE SAME STEM CELL OR A DIFFERENT CELL IS UNCLEAR, BUT AN UNSTABLE GENOME IN THE HSCS SEEMS TO BE THE COMMON ANTECEDENT. IN AN EFFORT TO CHARACTERIZE THE UNDERLYING GENETIC EVENTS THAT MIGHT CONTRIBUTE TO THE APPEARANCE OF MORE THAN ONE MPN IN A PATIENT, WE STUDIED NEOPLASTIC CELLS FROM PATIENTS WITH DUAL MPNS BY NEXT-GENERATION SEQUENCING. WE OBSERVED THAT MOST PATIENTS WITH TWO MPNS HARBORED MUTATIONS IN GENES KNOWN TO CONTRIBUTE TO CLONAL HEMATOPOIESIS THROUGH ALTERED EPIGENETIC REGULATION SUCH AS TET2, ASXL1/2, SRSF2, AND IDH2 AT VARYING FREQUENCIES (1%-47%). IN ADDITION, WE FOUND THAT SOME PATIENTS ALSO HARBORED ONCOGENIC MUTATIONS IN N/KRAS, TP53, BRAF, EZH2, AND GNAS AT LOW FREQUENCIES, WHICH PROBABLY REPRESENT CLONAL EVOLUTION. THESE FINDINGS SUPPORT THE HYPOTHESIS THAT HEMATOPOIETIC CELLS FROM MPN PATIENTS HARBOR MULTIPLE GENETIC ABERRATIONS, SOME OF WHICH CAN CONTRIBUTE TO CLONAL DOMINANCE. ACQUIRING MUTATIONS IN JAK2/CALR/MPL OR THE BCR-ABL TRANSLOCATION PROBABLY DRIVE THE ONCOGENIC PHENOTYPE TOWARDS A SPECIFIC MPN. FURTHER, WE PROPOSE THAT THE ACQUISITION OF BCR-ABL IN THESE PATIENTS IS FREQUENTLY A SECONDARY EVENT RESULTING FROM AN UNSTABLE GENOME. 2017 17 1070 24 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 18 5275 39 PROMOTER METHYLATION OF THE BONE MORPHOGENETIC PROTEIN-6 GENE IN ASSOCIATION WITH ADULT T-CELL LEUKEMIA. BONE MORPHOGENETIC PROTEINS (BMP), BELONGING TO THE TRANSFORMING GROWTH FACTOR-BETA SUPERFAMILY, ARE MULTIFUNCTIONAL REGULATORS OF CELL PROLIFERATION, DIFFERENTIATION AND APOPTOSIS IN VARIOUS TYPES OF MALIGNANT CELLS. IN THIS STUDY, WE INVESTIGATED BMP-6 PROMOTER METHYLATION IN PATIENTS WITH VARIOUS TYPES OF LEUKEMIAS. THE BMP-6 METHYLATION WAS FOUND PREFERENTIALLY IN ADULT T-CELL LEUKEMIA (ATL) (49 OF 60, 82%) COMPARED WITH OTHER TYPES OF LEUKEMIAS STUDIED INCLUDING ACUTE MYELOID LEUKEMIA (3 OF 67, 5%), ACUTE LYMPHOBLASTIC LEUKEMIA (6 OF 38, 16%) AND CHRONIC LYMPHOCYTIC LEUKEMIA (1 OF 21, 5%). AMONG SUBTYPES OF ATL, THE BMP-6 GENE WAS MORE FREQUENTLY METHYLATED IN AGGRESSIVE ATL FORMS OF ACUTE (96%) AND LYMPHOMA (94%) TYPES THAN LESS MALIGNANT CHRONIC ATL (44%) AND SMOLDERING ATL (20%). WE ALSO ANALYZED THE METHYLATION STATUS OF PERIPHERAL BLOOD MONONUCLEAR CELLS FROM HEALTHY DONORS AND NONMALIGNANT LYMPH NODES WITH REACTIVE LYMPHADENOPATHY, NONE OF WHICH SHOWED DETECTABLE BMP-6 METHYLATION IN THIS STUDY. THE BMP-6 METHYALTION WAS CORRELATED WITH DECREASED MRNA TRANSCRIPT AND PROTEIN EXPRESSION. EXPRESSION OF BMP-6 WAS RESTORED BY THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE, SUGGESTING THAT METHYLATION WAS ASSOCIATED WITH THE TRANSCRIPTIONAL SILENCING. SERIAL ANALYSIS DEMONSTRATED AN INCREASING METHYLATION OF CPG SITES IN THE BMP-6 PROMOTER AND THE RESULTANT SUPPRESSION OF BMP-6 EXPRESSION AS ATL PROGRESSED. THESE FINDINGS SUGGESTED THAT BMP-6 PROMOTER METHYLATION IS LIKELY TO BE A COMMON EPIGENETIC EVENT AT LATER STAGES OF ATL AND THAT THE METHYLATION PROFILES MAY BE USEFUL FOR THE STAGING OF ATL AS WELL AS FOR EVALUATION OF THE INDIVIDUAL RISK OF DEVELOPING THE DISEASE. 2008 19 4907 30 P53 ABERRATIONS DO NOT PREDICT INDIVIDUAL RESPONSE TO FLUDARABINE IN PATIENTS WITH B-CELL CHRONIC LYMPHOCYTIC LEUKAEMIA IN ADVANCED STAGES RAI III/IV. ABNORMALITIES OF P53 HAVE BEEN ASSOCIATED WITH SHORT SURVIVAL AND NON-RESPONSE TO THERAPY IN CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL). WE HAVE EVALUATED THE RATE OF RESPONSE TO FLUDARABINE AS FIRST-LINE THERAPY IN 54 PATIENTS WITH ADVANCED STAGE CLL, ANALYSING THE CYTOGENETIC PROFILE, ABERRATIONS IN P53, INCLUDING THE METHYLATION STATUS OF ITS PROMOTER, AND THE IMMUNOGLOBULIN HEAVY-CHAIN VARIABLE-REGION (IGVH) MUTATION STATUS. ACCORDING TO THE ADVANCED STAGE OF THE DISEASE IN THIS SERIES, 75% OF PATIENTS PRESENTED GENETIC ABERRATIONS ASSOCIATED WITH POOR PROGNOSIS: DEL(17P) AND/OR DEL(11Q), AND NO-MUTATED IGVH GENES. TEN PATIENTS (18.5%) HAD METHYLATION IN THE PROMOTER REGION OF P53. EIGHTY-THREE PER CENT OF PATIENTS TREATED ACHIEVED A RESPONSE, WITH A HIGH RATE OF COMPLETE REMISSION (47.6%). ALTHOUGH WE FOUND A SIGNIFICANT CORRELATION BETWEEN FAILURES AND THE PRESENCE OF P53 ABERRATIONS (P = 0.0065), EITHER WITH METHYLATION (P = 0.018) OR DELETION (P = 0.015), 64% OF THE PATIENTS WITH ABERRATIONS IN THIS GENE RESPONDED TO TREATMENT (11/17), SUGGESTING THAT FLUDARABINE INDUCES HIGH REMISSION RATES, EVEN IN THESE PATIENTS. THIS IS THE FIRST TIME THAT THE SIGNIFICANCE OF P53 PROMOTER METHYLATION STATUS IS DESCRIBED IN THIS PATHOLOGY, AND OUR DATA SUPPORT THAT THIS EPIGENETIC PHENOMENON COULD BE INVOLVED IN THE PATHOGENESIS AND CLINICAL EVOLUTION OF CLL. 2005 20 5270 36 PROMOTER DNA METHYLATION FREQUENCY AND CLINICOPATHOLOGICAL ROLE OF MIR-129-2 GENE IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA. OBJECTIVES: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY THE ACCUMULATION OF APPARENTLY MATURE B-TYPE LYMPHOCYTES IN THE LYMPHOHEMATOPOIETIC ORGANS. METHYLATION IN PROMOTERS OF TUMOR SUPPRESSOR GENES IS ONE OF THE MECHANISMS THAT CAUSES BLOOD MALIGNANCY. IN THIS STUDY, WE EVALUATED THE PROMOTER DNA METHYLATION STATUS OF MIR-129-2 TUMOR SUPPRESSOR GENE AND ITS ASSOCIATION WITH CLINICAL AND LABORATORY PARAMETERS OF PATIENTS WITH CLL. METHODS: WE STUDIED THE PROMOTER DNA METHYLATION FREQUENCY OF THE MIR-129-2 GENE IN 50 PATIENTS WITH CLL AND 50 HEALTHY CONTROLS USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION METHODS. STATISTICAL ANALYSIS WAS PERFORMED USING SPSS-18 SOFTWARE, AND A P-VALUE < 0.050 WAS CONSIDERED STATISTICALLY SIGNIFICANT. RESULTS: THE FREQUENCY OF PROMOTER DNA METHYLATION OF THE MIR-129-2 GENE WAS SIGNIFICANTLY HIGHER IN THE CLL GROUP COMPARED WITH CONTROL GROUP (38.0% VS. 0.0%, P < 0.001; CHI(2) = 23.457). THE PROMOTER DNA METHYLATION FREQUENCY OF MIR-129-2 GENE WAS NOT SIGNIFICANTLY DIFFERENT BETWEEN THE TWO SEXES (P = 0.236). A SIGNIFICANT BUT WEAK CORRELATION WAS SEEN BETWEEN THE METHYLATED STATE OF THE MIR-129-2 GENE AND ORGANOMEGALY (P = 0.019, R = 0.330) AS WELL AS HEMOGLOBIN LEVELS (P = 0.020, R = -0.233). HOWEVER, BINARY LOGISTIC REGRESSION ANALYSIS INDICATED ORGANOMEGALY AS THE ONLY CLINICAL BIOMARKER WITH A STATISTICALLY SIGNIFICANT ASSOCIATION WITH THE HYPERMETHYLATED MIR-129-2 GENE STATE (P = 0.046). CONCLUSIONS: THE HIGH FREQUENCY OF PROMOTER DNA METHYLATION OF THE MIR-129-2 GENE IN THE CLL GROUP COMPARED TO THE CONTROL GROUP, AS WELL AS ITS SIGNIFICANT ASSOCIATION WITH ORGANOMEGALY, SUGGESTS THE IMPORTANCE OF THIS EPIGENETIC BIOMARKER IN THE PATHOGENESIS AND PROGNOSIS OF CLL DISEASE. 2020