1 2465 136 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 2 3532 35 IMATINIB INDEPENDENT ABERRANT METHYLATION OF NOV/CCN3 IN CHRONIC MYELOGENOUS LEUKEMIA PATIENTS: A MECHANISM UPSTREAM OF BCR-ABL1 FUNCTION? BACKGROUND: THE NOV GENE PRODUCT, CCN3, HAS BEEN REPORTED IN A DIVERSE RANGE OF TUMORS TO SERVE AS A NEGATIVE GROWTH REGULATOR, WHILE ACTING AS A TUMOR SUPPRESSOR IN CHRONIC MYELOGENOUS LEUKEMIA (CML). HOWEVER, THE PRECISE MECHANISM OF ITS SILENCING IN CML IS POORLY UNDERSTOOD. IN THE CURRENT STUDY, WE AIMED TO QUERY IF THE GENE REGULATION OF CCN3 IS MEDIATED BY THE PROMOTER METHYLATION IN THE PATIENTS WITH CML. IN ADDITION, TO CLARIFY WHETHER THE EPIGENETIC SILENCING IS AFFECTED BY BCR-ABL1 INHIBITION, WE ASSESSED THE METHYLATION STATUS IN THE PATIENTS AT DIFFERENT TIME INTERVALS FOLLOWING THE TYROSINE KINASE INHIBITION USING IMATINIB THERAPY, AS THE FIRST-LINE TREATMENT FOR THIS TYPE OF LEUKEMIA. METHODS: TO ADDRESS THIS ISSUE, WE APPLIED BISULFITE-SEQUENCING TECHNIQUE AS A HIGH-RESOLUTION METHOD TO STUDY THE REGULATORY SEGMENT OF THE CCN3 GENE. THE RESULTS WERE ANALYZED IN NEWLY DIAGNOSED CML PATIENTS AS WELL AS FOLLOWING IMATINIB THERAPY. WE ALSO EVALUATED THE CORRELATION OF CCN3 PROMOTER METHYLATION WITH BCR-ABL1 LEVELS. RESULTS: OUR FINDINGS REVEALED THAT THE METHYLATION OCCURS FREQUENTLY IN THE PROMOTER REGION OF CML PATIENTS SHOWING A SIGNIFICANT INCREASE OF THE METHYLATED PERCENTAGE AT THE CPG SITES COMPARED TO NORMAL INDIVIDUALS. INTERESTINGLY, THIS HYPERMETHYLATION WAS INDICATED TO BE INDEPENDENT OF BCR-ABL1 TITERS IN BOTH GROUPS, WHICH MIGHT SUGGEST A MECHANISM BEYOND THE BCR-ABL1 FUNCTION. CONCLUSION: DESPITE SUGGESTING THAT THE CCN3 HYPERMETHYLATION ACTS AS A MOLECULAR MECHANISM INDEPENDENT OF BCR-ABL1 FUNCTION IN CML PATIENTS, THIS SCENARIO REQUIRES FURTHER VALIDATION BY COMPLEMENTARY EXPERIMENTS. IN THE CASE OF ACTING UPSTREAM OF BCR-ABL1 SIGNALING, THE METHYLATION MARKER CAN PROVIDE EARLY DETECTION AND A NOVEL PLATFORM FOR TARGETED EPIGENETIC MODIFIERS FOR EFFICIENT TREATMENT IN IMATINIB RESISTANT PATIENTS. 2019 3 139 35 ABERRANT DNA METHYLATION IS ASSOCIATED WITH DISEASE PROGRESSION, RESISTANCE TO IMATINIB AND SHORTENED SURVIVAL IN CHRONIC MYELOGENOUS LEUKEMIA. THE EPIGENETIC IMPACT OF DNA METHYLATION IN CHRONIC MYELOGENOUS LEUKEMIA (CML) IS NOT COMPLETELY UNDERSTOOD. TO ELUCIDATE ITS ROLE WE ANALYZED 120 PATIENTS WITH CML FOR METHYLATION OF PROMOTER-ASSOCIATED CPG ISLANDS OF 10 GENES. FIVE GENES WERE IDENTIFIED BY DNA METHYLATION SCREENING IN THE K562 CELL LINE AND 3 GENES IN PATIENTS WITH MYELOPROLIFERATIVE NEOPLASMS. THE CDKN2B GENE WAS SELECTED FOR ITS FREQUENT METHYLATION IN MYELOID MALIGNANCIES AND ABL1 AS THE TARGET OF BCR-ABL TRANSLOCATION. THIRTY PATIENTS WERE IMATINIB-NAIVE (MOSTLY TREATED BY INTERFERON-ALPHA BEFORE THE IMATINIB ERA), 30 WERE IMATINIB-RESPONSIVE, 50 WERE IMATINIB-RESISTANT, AND 10 WERE IMATINIB-INTOLERANT. WE QUANTIFIED DNA METHYLATION BY BISULFITE PYROSEQUENCING. THE AVERAGE NUMBER OF METHYLATED GENES WAS 4.5 PER PATIENT IN THE CHRONIC PHASE, INCREASING SIGNIFICANTLY TO 6.2 IN THE ACCELERATED AND 6.4 IN THE BLASTIC PHASE. HIGHER NUMBERS OF METHYLATED GENES WERE ALSO OBSERVED IN PATIENTS RESISTANT OR INTOLERANT TO IMATINIB. THESE PATIENTS ALSO SHOWED ALMOST EXCLUSIVE METHYLATION OF A PUTATIVE TRANSPORTER OSCP1. ABNORMAL METHYLATION OF A SRC SUPPRESSOR GENE PDLIM4 WAS ASSOCIATED WITH SHORTENED SURVIVAL INDEPENDENTLY OF CML STAGE AND IMATINIB RESPONSIVENESS. WE CONCLUDE THAT ABERRANT DNA METHYLATION IS ASSOCIATED WITH CML PROGRESSION AND THAT DNA METHYLATION COULD BE A MARKER ASSOCIATED WITH IMATINIB RESISTANCE. FINALLY, DNA METHYLATION OF PDLIM4 MAY HELP IDENTIFY A SUBSET OF CML PATIENTS THAT WOULD BENEFIT FROM TREATMENT WITH SRC/ABL INHIBITORS. 2011 4 4388 51 MLL2/KMT2D AND MLL3/KMT2C EXPRESSION CORRELATES WITH DISEASE PROGRESSION AND RESPONSE TO IMATINIB MESYLATE IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: CHRONIC MYELOID LEUKEMIA (CML) IS A CLONAL MYELOPROLIFERATIVE NEOPLASM WHOSE PATHOGENESIS IS LINKED TO THE PHILADELPHIA CHROMOSOME PRESENCE THAT GENERATES THE BCR-ABL1 FUSION ONCOGENE. TYROSINE KINASE INHIBITORS (TKI) SUCH AS IMATINIB MESYLATE (IM) DRAMATICALLY IMPROVED THE TREATMENT EFFICIENCY AND SURVIVAL OF CML PATIENTS BY TARGETING BCR-ABL TYROSINE KINASE. THE DISEASE SHOWS THREE DISTINCT CLINICAL-LABORATORY STAGES: CHRONIC PHASE, ACCELERATED PHASE AND BLAST CRISIS. ALTHOUGH PATIENTS IN THE CHRONIC PHASE RESPOND WELL TO TREATMENT, PATIENTS IN THE ACCELERATED PHASE OR BLAST CRISIS USUALLY SHOW THERAPY RESISTANCE AND CML RELAPSE. IT IS CRUCIAL, THEREFORE, TO IDENTIFY BIOMARKERS TO PREDICT CML GENETIC EVOLUTION AND RESISTANCE TO TKI THERAPY, CONSIDERING NOT ONLY THE EFFECTS OF GENETIC ABERRATIONS BUT ALSO THE ROLE OF EPIGENETIC ALTERATIONS DURING THE DISEASE. ALTHOUGH DYSREGULATIONS IN EPIGENETIC MODULATORS SUCH AS HISTONE METHYLTRASNFERASES HAVE ALREADY BEEN DESCRIBED FOR SOME HEMATOLOGIC MALIGNANCIES, TO DATE VERY LIMITED DATA IS AVAILABLE FOR CML, ESPECIALLY WHEN CONSIDERING THE LYSINE METHYLTRANSFERASE MLL2/KMT2D AND MLL3/KMT2C. METHODS: HERE WE INVESTIGATED THE EXPRESSION PROFILE OF BOTH GENES IN CML PATIENTS IN DIFFERENT STAGES OF THE DISEASE, IN PATIENTS SHOWING DIFFERENT RESPONSES TO THERAPY WITH IM AND IN NON-NEOPLASTIC CONTROL SAMPLES. IMATINIB SENSITIVE AND RESISTANT CML CELL LINES WERE ALSO USED TO INVESTIGATE WHETHER TREATMENT WITH OTHER TYROSINE KINASE INHIBITORS INTERFERED IN THEIR EXPRESSION. RESULTS: IN PATIENTS, BOTH METHYLTRANSFERASES WERE EITHER UPREGULATED OR WITH BASAL EXPRESSION LEVEL DURING THE CHRONIC PHASE COMPARED TO CONTROLS. INTERESTINGLY, MLL3/KMT2C AND SPECIALLY MLL2/KMT2D LEVELS DECREASED DURING DISEASE PROGRESSION CORRELATING WITH DISTINCT CLINICAL STAGES. FURTHERMORE, MLL2/KMT2D WAS DECREASED IN PATIENTS RESISTANT TO IM TREATMENT. A RESCUE IN THE EXPRESSION OF BOTH MLL GENES WAS OBSERVED IN KCL22S, A CML CELL LINE SENSITIVE TO IM, AFTER TREATMENT WITH DASATINIB OR NILOTINIB WHICH WAS ASSOCIATED WITH A HIGHER RATE OF APOPTOSIS, AN ENHANCED EXPRESSION OF P21 (CDKN1A) AND A CONCOMITANT DECREASE IN THE EXPRESSION OF CDK2, CDK4 AND CYCLIN B1 (CCNB1) IN COMPARISON TO UNTREATED KCL22S CONTROL OR IM RESISTANT KCL22R CELL LINE, WHICH SUGGESTS INVOLVEMENT OF P53 REGULATED PATHWAY. CONCLUSION: OUR RESULTS ESTABLISHED A NEW ASSOCIATION BETWEEN MLL2/KMT2D AND MLL3/KMT2C GENES WITH CML AND SUGGEST THAT MLL2/KMT2D IS ASSOCIATED WITH DISEASE EVOLUTION AND MAY BE A POTENTIAL MARKER TO PREDICT THE DEVELOPMENT OF THERAPY RESISTANCE. 2018 5 5762 38 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 6 536 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 7 149 36 ABERRANT HYDROXYMETHYLATION IN PROMOTER CPG REGIONS OF GENES RELATED TO THE CELL CYCLE AND APOPTOSIS CHARACTERIZES ADVANCED CHRONIC MYELOID LEUKEMIA DISEASE, POOR IMATINIB RESPONDENTS AND POOR SURVIVAL. BACKGROUND: THERE IS STRONG EVIDENCE THAT DISEASE PROGRESSION, DRUG RESPONSE AND OVERALL CLINICAL OUTCOMES OF CML DISEASE ARE NOT ONLY DECIDED BY BCR/ABL1 ONCOPROTEIN BUT DEPEND ON ACCUMULATION OF ADDITIONAL GENETIC AND EPIGENETIC ABERRATIONS. DNA HYDROXYMETHYLATION IS IMPLICATED IN THE DEVELOPMENT OF VARIETY OF DISEASES. DNA HYDROXYMETHYLATION IN GENE PROMOTERS PLAYS IMPORTANT ROLES IN DISEASE PROGRESSION, DRUG RESPONSE AND CLINICAL OUTCOME OF VARIOUS DISEASES. THEREFORE IN THIS STUDY, WE AIMED TO EXPLORE THE ROLE OF ABERRANT HYDROXYMETHYLATION IN PROMOTER REGIONS OF DIFFERENT TUMOR SUPPRESSOR GENES IN RELATION TO CML DISEASE PROGRESSION, RESPONSE TO IMATINIB THERAPY AND CLINICAL OUTCOME. METHODS: WE RECRUITED 150 CML PATIENTS AT DIFFERENT CLINICAL STAGES OF THE DISEASE. PATIENTS WERE FOLLOWED UP FOR 48 MONTHS AND HAEMATOLOGICAL/MOLECULAR RESPONSES WERE ANALYSED. HAEMATOLOGICAL RESPONSE WAS ANALYSED BY PERIPHERAL BLOOD SMEAR. BCR/ABL1 SPECIFIC TAQMAN PROBE BASED QRT-PCR WAS USED FOR ASSESSING THE MOLECULAR RESPONSE OF CML PATIENTS ON IMATINIB THERAPY. PROMOTER HYDROXYMETHYLATION OF THE GENES WAS CHARACTERIZED USING MS-PCR. RESULTS: WE OBSERVED THAT PROMOTER HYDROXYMETHYLATION OF DAPK1, RIZ1, P16INK4A, RASSF1A AND P14ARF(ARF) GENES CHARACTERIZE ADVANCED CML DISEASE AND POOR IMATINIB RESPONDENTS. ALTHOUGH, CYTOKINE SIGNALLING (SOCS1) GENE WAS HYPERMETHYLATED IN ADVANCED STAGES OF CML AND ACCUMULATED IN PATIENTS WITH POOR IMATINIB RESPONSE, BUT THE DIFFERENCES WERE NOT STATISTICALLY SIGNIFICANT. MOREOVER, WE FOUND HYPERMETHYLATION OF P14(ARF), RASSF1 AND P16(INK4A) GENES AND CYTOKINE SIGNALLING GENE (SOCS1) SIGNIFICANTLY ASSOCIATED WITH POOR OVERALL SURVIVAL OF CML PATIENTS ON IMATINIB THERAPY. THE RESULTS OF THIS STUDY ARE IN AGREEMENT OF THE ROLE OF ABERRANT DNA METHYLATION OF DIFFERENT TUMOR SUPPRESSOR GENES AS POTENTIAL BIOMARKERS OF CML DISEASE PROGRESSION, POOR IMATINIB RESPONSE AND OVERALL CLINICAL OUTCOME. CONCLUSION: IN THIS STUDY, WE REPORT THAT PROMOTER HYDROXYMETHYLATION OF DAPK1, RIZ1, P16INK4A, RASSF1A AND P14ARF(ARF) GENES IS A CHARACTERISTIC FEATURE OF CML DISEASE PROGRESSIONS, DEFINES POOR IMATINIB RESPONDENTS AND POOR OVERALL SURVIVAL OF CML PATIENTS TO IMATINIB THERAPY. 2022 8 5669 31 SFRP1 PROMOTER METHYLATION IS ASSOCIATED WITH PERSISTENT PHILADELPHIA CHROMOSOME IN CHRONIC MYELOID LEUKEMIA. EPIGENETIC SILENCING OF SFRP GENES HAS BEEN SHOWN TO LEAD TO CONSTITUTIVE ACTIVATION OF THE CANONICAL WNT-SIGNALING PATHWAY. THE FIRST DESCRIPTION OF DEREGULATED WNT-SIGNALING ACTIVATION IN A HEMATOLOGICAL MALIGNANCY WAS REPORTED IN CHRONIC MYELOID LEUKEMIA (CML). TO INVESTIGATE WHETHER EPIGENETIC SILENCING OF SFRP IS RESPONSIBLE FOR THE OBSERVED WNT ACTIVATION IN CML, WE STUDIED THE METHYLATION AND MUTATIONAL STATUS OF THE SFRP1 PROMOTER IN 48 CHRONIC PHASE CML PATIENTS. OF THE 48 CML PATIENTS 41 WERE SHOWN TO BE UNMETHYLATED, 6 PATIENTS HEMI-METHYLATED AND 1 PATIENT FULLY METHYLATED AT THE SFRP1 PROMOTER. ALBEIT OBSERVED INFREQUENTLY IN CHRONIC PHASE CML, SFRP1 PROMOTER METHYLATION CORRELATED WITH PRIMARY CYTOGENETIC RESISTANCE TO IMATINIB MESYLATE. SFRP1 PROMOTER METHYLATION MAY INDICATE A GENETICALLY MORE UNSTABLE FORM OF DISEASE RESISTANT TO THERAPY AND PROVIDE A KEY BIOLOGICAL DIFFERENCE IN THERAPY RESISTANT PATIENTS, IN ADDITION TO A POSSIBLE MECHANISM FOR THE OBSERVED ACTIVATION OF CANONICAL WNT SIGNALING IN CML. 2009 9 4694 37 NEXT-GENERATION SEQUENCING IDENTIFIES MAJOR DNA METHYLATION CHANGES DURING PROGRESSION OF PH+ CHRONIC MYELOID LEUKEMIA. LITTLE IS KNOWN ABOUT THE IMPACT OF DNA METHYLATION ON THE EVOLUTION/PROGRESSION OF PH+ CHRONIC MYELOID LEUKEMIA (CML). WE INVESTIGATED THE METHYLOME OF CML PATIENTS IN CHRONIC PHASE (CP-CML), ACCELERATED PHASE (AP-CML) AND BLAST CRISIS (BC-CML) AS WELL AS IN CONTROLS BY REDUCED REPRESENTATION BISULFITE SEQUENCING. ALTHOUGH ONLY ~600 DIFFERENTIALLY METHYLATED CPG SITES WERE IDENTIFIED IN SAMPLES OBTAINED FROM CP-CML PATIENTS COMPARED WITH CONTROLS, ~6500 DIFFERENTIALLY METHYLATED CPG SITES WERE FOUND IN SAMPLES FROM BC-CML PATIENTS. IN THE MAJORITY OF AFFECTED CPG SITES, METHYLATION WAS INCREASED. IN CP-CML PATIENTS WHO PROGRESSED TO AP-CML/BC-CML, WE IDENTIFIED UP TO 897 GENES THAT WERE METHYLATED AT THE TIME OF PROGRESSION BUT NOT AT THE TIME OF DIAGNOSIS. USING RNA-SEQUENCING, WE OBSERVED DOWNREGULATED EXPRESSION OF MANY OF THESE GENES IN BC-CML COMPARED WITH CP-CML SAMPLES. SEVERAL OF THEM ARE WELL-KNOWN TUMOR-SUPPRESSOR GENES OR REGULATORS OF CELL PROLIFERATION, AND GENE RE-EXPRESSION WAS OBSERVED BY THE USE OF EPIGENETIC ACTIVE DRUGS. TOGETHER, OUR RESULTS DEMONSTRATE THAT CPG SITE METHYLATION CLEARLY INCREASES DURING CML PROGRESSION AND THAT IT MAY PROVIDE A USEFUL BASIS FOR REVEALING NEW TARGETS OF THERAPY IN ADVANCED CML. 2016 10 5055 35 PHASE 2 TRIAL OF THE HISTONE DEACETYLASE INHIBITOR ROMIDEPSIN FOR THE TREATMENT OF REFRACTORY MULTIPLE MYELOMA. BACKGROUND: EPIGENETIC DYSREGULATION IS A HALLMARK OF CANCER, INCLUDING MULTIPLE MYELOMA. INHIBITORS OF HISTONE DEACETYLASES (HDACS) INDUCE DNA HYPERACETYLATION BY INHIBITING REMOVAL OF ACETYL GROUPS FROM AMINO TAILS ON HISTONE PROTEINS, THEREBY UNCOILING CONDENSED CHROMATIN FAVORING TRANSCRIPTION OF SILENCED GENES, INCLUDING TUMOR SUPPRESSOR GENES. ROMIDEPSIN IS AN HDAC INHIBITOR THAT EXHIBITS ANTIPROLIFERATIVE AND APOPTOTIC EFFECTS AGAINST MULTIPLE MYELOMA CELL LINES. METHODS: A PHASE 2 TRIAL WAS PERFORMED OF ROMIDEPSIN IN PATIENTS WITH MULTIPLE MYELOMA WHO WERE REFRACTORY TO STANDARD THERAPY. TREATMENT WAS COMPRISED OF ROMIDEPSIN (13 MG/M(2)) GIVEN AS A 4-HOUR INTRAVENOUS INFUSION ON DAYS 1, 8, AND 15 EVERY 28 DAYS). THIRTEEN PATIENTS RECEIVED A MEDIAN OF 2 CYCLES OF THERAPY (RANGE, 1-7 CYCLES). RESULTS: ALTHOUGH NO PATIENTS HAD AN OBJECTIVE RESPONSE, 4 OF 12 PATIENTS WITH SECRETORY MYELOMA EXHIBITED EVIDENCE OF M-PROTEIN STABILIZATION, AND SEVERAL OTHER PATIENTS EXPERIENCED IMPROVEMENT IN BONE PAIN AND RESOLUTION OF HYPERCALCEMIA. CONCLUSIONS: THE RESULTS OF THE CURRENT STUDY DEMONSTRATE THAT ROMIDEPSIN, AS A SINGLE AGENT, IS UNLIKELY TO BE ASSOCIATED WITH A RESPONSE RATE OF >/=30% IN PATIENTS WITH REFRACTORY MYELOMA, ALTHOUGH THERE WAS SOME CLINICAL EVIDENCE SUGGESTING A BIOLOGICAL EFFECT ASSOCIATED WITH THERAPY. 2011 11 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 12 1272 32 CYTOTOXIC ACTIVITY OF VALPROIC ACID ON PRIMARY CHRONIC LYMPHOCYTIC LEUKEMIA CELLS. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON ADULT LEUKEMIA IN WESTERN CIVILIZATION. THE ACCUMULATION OF CD5+CD19+ B LYMPHOCYTES IN PERIPHERAL BLOOD IS DUE TO A DEFECT IN THE APOPTOTIC PATHWAY RATHER THAN EXCESSIVE PROLIFERATION IN THE BONE MARROW AND LYMPH NODES. DESPITE A NUMBER OF TREATMENTS, CLL REMAINS AN INCURABLE DISEASE. VALPROIC ACID (VPA) ACTIVITY, AS A HISTONE DEACETYLASE INHIBITOR, COULD RESTORE THE EPIGENETIC CHANGES UNDERLYING THE PATHOGENESIS OF CLL AND THUS INDUCE CELL DEATH. OBJECTIVES: IN THE PRESENT STUDY WE HYPOTHESIZED THAT VPA COULD INDUCE CLL PRIMARY CELLS DEATH THROUGH ACTIVATION OF APOPTOSIS. MATERIAL AND METHODS: PERIPHERAL BLOOD SAMPLES WERE OBTAINED FROM 53 CLL PATIENTS. PERIPHERAL BLOOD MONONUCLEAR CELLS WERE ISOLATED THROUGH DENSITY GRADIENT CENTRIFUGATION AND WERE THE SUBJECT OF A 24-HOUR CELL CULTURE WITH 10 MM OF VPA. THE CYTOTOXIC EFFECT OF VPA WAS EVALUATED WITH AN XTT TEST AND THEREAFTER CONFIRMED USING ANNEXIN V-FITC/PI STAINING AND FLOW CYTOMETRY TECHNIQUES. RESULTS: IN THIS STUDY, A MEDIAN VPA CYTOTOXICITY OF 13.88% WITH A RANGE OF 0-54.65% WAS OBSERVED. ANNEXIN V/PI STAINING CONFIRMED THAT THE DEMONSTRATED CYTOTOXICITY WAS CAUSED BY INCREASED APOPTOSIS IN THE VPA TREATED CELLS AS COMPARED TO CONTROL CELLS. STATISTICAL ANALYSIS SHOWED THAT VPA'S EFFECT ON CLL CELLS DEPENDS ON LACTATE DEHYDROGENASE SERUM LEVELS, BUT IS INDEPENDENT OF ALL OTHER PROGNOSTIC MARKERS. CONCLUSIONS: THE RESULTS OF THE PRESENT EXPERIMENTS FOUND THAT VPA AT A CLINICALLY APPLICABLE CONCENTRATION SIGNIFICANTLY INDUCES APOPTOSIS INDEPENDENTLY OF THE DISEASE STAGE AND MIGHT BE A VALUABLE THERAPEUTIC AGENT FOR ALL CLL PATIENTS. 2015 13 3098 30 GENOMIC DISRUPTION OF THE HISTONE METHYLTRANSFERASE SETD2 IN CHRONIC LYMPHOCYTIC LEUKAEMIA. HISTONE METHYLTRANSFERASES (HMTS) ARE IMPORTANT EPIGENETIC REGULATORS OF GENE TRANSCRIPTION AND ARE DISRUPTED AT THE GENOMIC LEVEL IN A SPECTRUM OF HUMAN TUMOURS INCLUDING HAEMATOLOGICAL MALIGNANCIES. USING HIGH-RESOLUTION SINGLE NUCLEOTIDE POLYMORPHISM (SNP) ARRAYS, WE IDENTIFIED RECURRENT DELETIONS OF THE SETD2 LOCUS IN 3% (8/261) OF CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) PATIENTS. FURTHER VALIDATION IN TWO INDEPENDENT COHORTS SHOWED THAT SETD2 DELETIONS WERE ASSOCIATED WITH LOSS OF TP53, GENOMIC COMPLEXITY AND CHROMOTHRIPSIS. WITH NEXT-GENERATION SEQUENCING WE DETECTED MUTATIONS OF SETD2 IN AN ADDITIONAL 3.8% OF PATIENTS (23/602). IN MOST CASES, SETD2 DELETIONS OR MUTATIONS WERE OFTEN OBSERVED AS A CLONAL EVENT AND ALWAYS AS A MONO-ALLELIC LESION, LEADING TO REDUCED MRNA EXPRESSION IN SETD2-DISRUPTED CASES. PATIENTS WITH SETD2 ABNORMALITIES AND WILD-TYPE TP53 AND ATM FROM FIVE CLINICAL TRIALS EMPLOYING CHEMOTHERAPY OR CHEMO-IMMUNOTHERAPY HAD REDUCED PROGRESSION-FREE AND OVERALL SURVIVAL COMPARED WITH CASES WILD TYPE FOR ALL THREE GENES. CONSISTENT WITH ITS POSTULATED ROLE AS A TUMOUR SUPPRESSOR, OUR DATA HIGHLIGHT SETD2 ABERRATION AS A RECURRENT, EARLY LOSS-OF-FUNCTION EVENT IN CLL PATHOBIOLOGY LINKED TO AGGRESSIVE DISEASE. 2016 14 59 34 A GENOME-WIDE SCREEN IDENTIFIES FREQUENTLY METHYLATED GENES IN HAEMATOLOGICAL AND EPITHELIAL CANCERS. BACKGROUND: GENETIC AS WELL AS EPIGENETIC ALTERATIONS ARE A HALLMARK OF BOTH EPITHELIAL AND HAEMATOLOGICAL MALIGNANCIES. HIGH THROUGHPUT SCREENS ARE REQUIRED TO IDENTIFY EPIGENETIC MARKERS THAT CAN BE USEFUL FOR DIAGNOSTIC AND PROGNOSTIC PURPOSES ACROSS MALIGNANCIES. RESULTS: HERE WE REPORT FOR THE FIRST TIME THE USE OF THE MIRA ASSAY (METHYLATED CPG ISLAND RECOVERY ASSAY) IN COMBINATION WITH GENOME-WIDE CPG ISLAND ARRAYS TO IDENTIFY EPIGENETIC MOLECULAR MARKERS IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) ON A GENOME-WIDE SCALE. WE IDENTIFIED 30 GENES DEMONSTRATING METHYLATION FREQUENCIES OF > OR =25% IN CHILDHOOD ALL, NINE GENES SHOWED SIGNIFICANTLY DIFFERENT METHYLATION FREQUENCIES IN B VS T-ALL. FOR MAJORITY OF THE GENES EXPRESSION COULD BE RESTORED IN METHYLATED LEUKEMIA LINES AFTER TREATMENT WITH 5-AZADC. FORTY-FOUR PERCENT OF THE GENES REPRESENT TARGETS OF THE POLYCOMB COMPLEX. IN CHRONIC MYELOID LEUKEMIA (CML) TWO OF THE GENES, (TFAP2A AND EBF2), DEMONSTRATED INCREASED METHYLATION IN BLAST CRISIS COMPARED TO CHRONIC PHASE (P < 0.05). FURTHERMORE HYPERMETHYLATION OF AN AUTOPHAGY RELATED GENE ATG16L2 WAS ASSOCIATED WITH POORER PROGNOSIS IN TERMS OF MOLECULAR RESPONSE TO IMATINIB TREATMENT. LASTLY WE DEMONSTRATED THAT TEN OF THESE GENES WERE ALSO FREQUENTLY METHYLATED IN COMMON EPITHELIAL CANCERS. CONCLUSION: IN SUMMARY WE HAVE IDENTIFIED A LARGE NUMBER OF GENES SHOWING FREQUENT METHYLATION IN CHILDHOOD ALL, METHYLATION STATUS OF TWO OF THESE GENES IS ASSOCIATED WITH ADVANCED DISEASE IN CML AND METHYLATION STATUS OF ANOTHER GENE IS ASSOCIATED WITH PROGNOSIS. IN ADDITION A SUBSET OF THESE GENES MAY ACT AS EPIGENETIC MARKERS ACROSS HEMATOLOGICAL MALIGNANCIES AS WELL AS COMMON EPITHELIAL CANCERS. 2010 15 2462 29 EPIGENETIC THERAPY OF MYELODYSPLASTIC SYNDROMES CONNECTS TO CELLULAR DIFFERENTIATION INDEPENDENTLY OF ENDOGENOUS RETROELEMENT DEREPRESSION. BACKGROUND: MYELODYSPLASTIC SYNDROMES (MDS) AND ACUTE MYELOID LEUKAEMIA (AML) ARE CHARACTERISED BY ABNORMAL EPIGENETIC REPRESSION AND DIFFERENTIATION OF BONE MARROW HAEMATOPOIETIC STEM CELLS (HSCS). DRUGS THAT REVERSE EPIGENETIC REPRESSION, SUCH AS 5-AZACYTIDINE (5-AZA), INDUCE HAEMATOLOGICAL IMPROVEMENT IN HALF OF TREATED PATIENTS. ALTHOUGH THE MECHANISMS UNDERLYING THERAPY SUCCESS ARE NOT YET CLEAR, INDUCTION OF ENDOGENOUS RETROELEMENTS (ERES) HAS BEEN HYPOTHESISED. METHODS: USING RNA SEQUENCING (RNA-SEQ), WE COMPARED THE TRANSCRIPTION OF ERES IN BONE MARROW HSCS FROM A NEW COHORT OF MDS AND CHRONIC MYELOMONOCYTIC LEUKAEMIA (CMML) PATIENTS BEFORE AND AFTER 5-AZA TREATMENT WITH HSCS FROM HEALTHY DONORS AND AML PATIENTS. WE FURTHER EXAMINED ERE TRANSCRIPTION USING THE MOST COMPREHENSIVE ANNOTATION OF ERE-OVERLAPPING TRANSCRIPTS EXPRESSED IN HSCS, GENERATED HERE BY DE NOVO TRANSCRIPT ASSEMBLY AND SUPPORTED BY FULL-LENGTH RNA-SEQ. RESULTS: CONSISTENT WITH PRIOR REPORTS, WE FOUND THAT TREATMENT WITH 5-AZA INCREASED THE REPRESENTATION OF ERE-DERIVED RNA-SEQ READS IN THE TRANSCRIPTOME. HOWEVER, SUCH INCREASES WERE COMPARABLE BETWEEN TREATMENT RESPONSES AND FAILURES. THE EXTENDED VIEW OF HSC TRANSCRIPTIONAL DIVERSITY OFFERED BY DE NOVO TRANSCRIPT ASSEMBLY ARGUED AGAINST 5-AZA-RESPONSIVE ERES AS DETERMINANTS OF THE OUTCOME OF THERAPY. INSTEAD, IT UNCOVERED PRE-TREATMENT EXPRESSION AND ALTERNATIVE SPLICING OF DEVELOPMENTALLY REGULATED GENE TRANSCRIPTS AS PREDICTORS OF THE RESPONSE OF MDS AND CMML PATIENTS TO 5-AZA TREATMENT. CONCLUSIONS: OUR STUDY IDENTIFIES THE DEVELOPMENTALLY REGULATED TRANSCRIPTIONAL SIGNATURES OF PROTEIN-CODING AND NON-CODING GENES, RATHER THAN ERES, AS CORRELATES OF A FAVOURABLE RESPONSE OF MDS AND CMML PATIENTS TO 5-AZA TREATMENT AND OFFERS NOVEL CANDIDATES FOR FURTHER EVALUATION. 2019 16 5102 33 POLYCOMB GENES ARE ASSOCIATED WITH RESPONSE TO IMATINIB IN CHRONIC MYELOID LEUKEMIA. AIM: IMATINIB IS A TYROSINE KINASE INHIBITOR THAT HAS REVOLUTIONIZED THE TREATMENT OF CHRONIC MYELOID LEUKEMIA (CML). DESPITE ITS EFFICACY, ABOUT A THIRD OF PATIENTS DISCONTINUE THE TREATMENT DUE TO THERAPY FAILURE OR INTOLERANCE. THE RATIONAL IDENTIFICATION OF PATIENTS LESS LIKELY TO RESPOND TO IMATINIB WOULD BE OF PARAMOUNT CLINICAL RELEVANCE. WE HAVE SHOWN THAT TRANSMEMBRANE TRANSPORTER HOCT1 GENOTYPING PREDICTS IMATINIB ACTIVITY. IN PARALLEL, POLYCOMB GROUP GENES (PCGS) ARE EPIGENETIC REPRESSORS IMPLICATED IN CML PROGRESSION AND IN THERAPY RESISTANCE. PATIENTS & METHODS: WE MEASURED THE EXPRESSION OF EIGHT PCGS IN PAIRED PRE- AND POST-IMATINIB BONE MARROW SAMPLES FROM 30 CML PATIENTS. RESULTS: BMI1, PHC3, CBX6 AND CBX7 EXPRESSION WAS SIGNIFICANTLY INCREASED DURING IMATINIB TREATMENT. POST-TREATMENT LEVELS OF CBX6 AND CBX7 PREDICTED 3-MONTH RESPONSE RATE. MEASUREMENT OF POST-TREATMENT BMI1 LEVELS IMPROVED THE PREDICTIVE POWER OF HOCT1 GENOTYPING. CONCLUSION: THESE RESULTS SUGGEST THAT THE EXPRESSION LEVELS OF PCGS MIGHT BE USEFUL FOR A MORE ACCURATE RISK STRATIFICATION OF CML PATIENTS. 2015 17 151 22 ABERRANT METHYLATION AND IMPAIRED EXPRESSION OF THE P15(INK4B) CELL CYCLE REGULATORY GENE IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML). THE IMPORTANT CELL CYCLE REGULATORY GENE P15(INK4B) HAS BEEN SHOWN TO BE INACTIVATED IN ACUTE MYELOID LEUKEMIA AND MYELODYSPLASTIC SYNDROME. LITTLE IS KNOWN ABOUT THE EXPRESSION AND EPIGENETIC MODIFICATION OF THIS GENE IN CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) THAT BELONGS TO THE MYELODYSPLASTIC/MYELOPROLIFERATIVE DISORDERS (MDS/MPD) WITH A HIGH PROPORTION OF BLASTIC TRANSFORMATION. ANALYSIS OF BONE MARROW TREPHINES IN A SERIES OF 33 CMML CASES SHOWED AN ABERRANT P15(INK4B) GENE METHYLATION IN UP TO 58% OF CASES. METHYLATION WAS ANALYZED EMPLOYING DIFFERENT METHYLATION-SPECIFIC PCR AND GENOMIC SEQUENCING PROTOCOLS. IT TURNED OUT TO BE SPREAD OVER A BROAD AREA OF THE 5' REGION AND EXHIBITED SUBSTANTIAL HETEROGENEITY BETWEEN CASES AND EVEN IN INDIVIDUAL PATIENTS. THE DEGREE OF ABERRANT METHYLATION WAS CORRELATED WITH A REDUCED MRNA AS WELL AS REDUCED PROTEIN EXPRESSION, AND WAS ASSOCIATED WITH A HIGHER EXPRESSION OF DNA METHYLTRANSFERASE DNMT 3A. WE CONCLUDE THAT ABERRANT GENE METHYLATION IS A FREQUENT EVENT IN CMML THAT MIGHT CONTRIBUTE TO THE PATHOGENESIS OF THIS MDS/MPD. 2003 18 6689 47 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 19 3461 32 HYPOMETHYLATION-MEDIATED H19 OVEREXPRESSION INCREASES THE RISK OF DISEASE EVOLUTION THROUGH THE ASSOCIATION WITH BCR-ABL TRANSCRIPT IN CHRONIC MYELOID LEUKEMIA. PREVIOUS STUDY HAS REVEALED THAT H19 EXPRESSION IS REQUIRED FOR EFFICIENT TUMOR GROWTH INDUCED BY BCR-ABL IN CHRONIC MYELOID LEUKEMIA (CML). HEREIN, WE FURTHER DETERMINED H19 EXPRESSION AND ITS CLINICAL IMPLICATION IN PATIENTS WITH CML. H19 EXPRESSION AND METHYLATION WERE DETECTED BY REAL-TIME QUANTITATIVE PCR AND REAL-TIME QUANTITATIVE METHYLATION-SPECIFIC PCR, AND THEN CLINICAL IMPLICATION OF H19 EXPRESSION WAS FURTHER ANALYZED. H19 EXPRESSION WAS SIGNIFICANTLY UP-REGULATED IN CML PATIENTS (P < 0.001). H19 EXPRESSION WITH AN AREA UNDER RECEIVER OPERATING CHARACTERISTIC CURVE VALUE OF 0.824 MIGHT SERVE AS A PROMISING BIOMARKER IN DISTINGUISHING CML PATIENTS FROM CONTROLS. THE PATIENTS WITH HIGH H19 EXPRESSION HAD A TENDENCY OF HIGHER WHITE BLOOD CELLS AND BCR-ABL TRANSCRIPT THAN THOSE WITH LOW H19 EXPRESSION. H19 OVEREXPRESSION OCCURRED WITH THE HIGHER FREQUENCY IN BLAST CRISIS STAGE (11/11, 100%), LOWER IN ACCELERATED PHASE (3/5, 60%), AND CHRONIC PHASE (42/62, 66%) STAGES. MOREOVER, PAIRED PATIENTS DURING DISEASE PROGRESSION WITH INCREASED BCR-ABL TRANSCRIPT ALSO SHOWED A SIGNIFICANT UPREGULATION OF H19 EXPRESSION. MEANWHILE, H19 EXPRESSION WAS DECREASED IN FOLLOW-UP PATIENTS WHO ACHIEVED COMPLETE MOLECULAR REMISSION AFTER TYROSINE KINASE INHIBITORS-BASED THERAPY. EPIGENETIC STUDIES SHOWED THAT H19 DIFFERENTIALLY METHYLATED REGION/IMPRINTING CONTROL REGION (DMR/ICR) WAS HYPOMETHYLATED AND ASSOCIATED WITH H19 EXPRESSION IN CML PATIENTS. MOREOVER, DEMETHYLATION OF H19 DMR/ICR REACTIVATED H19 EXPRESSION IN K562 CELLS. COLLECTIVELY, H19 OVEREXPRESSION, A FREQUENT EVENT IN CML, WAS ASSOCIATED WITH HIGHER BCR-ABL TRANSCRIPT INVOLVING IN DISEASE PROGRESSION. MOREOVER, H19 DMR/ICR HYPOMETHYLATION IN CML MAY BE ONE OF THE MECHANISMS MEDIATING H19 OVEREXPRESSION. 2018 20 5259 32 PROGRESSIVE DE NOVO DNA METHYLATION AT THE BCR-ABL LOCUS IN THE COURSE OF CHRONIC MYELOGENOUS LEUKEMIA. DE NOVO METHYLATION OF CPG ISLANDS IS A RARE EVENT IN MAMMALIAN CELLS. IT HAS BEEN OBSERVED IN THE COURSE OF DEVELOPMENTAL PROCESSES, SUCH AS X CHROMOSOME INACTIVATION AND GENOMIC IMPRINTING. THE METHYLATION OF DNA, AN IMPORTANT FACTOR IN THE EPIGENETIC CONTROL OF GENE EXPRESSION, MAY ALSO BE INVOLVED IN TUMORIGENESIS. AFTER THE T(9;22) CHROMOSOMAL TRANSLOCATION AND GENERATION OF THE PHILADELPHIA CHROMOSOME, THE INITIATING EVENT IN CHRONIC MYELOGENOUS LEUKEMIA (CML), MOST OF THE ABL CODING SEQUENCE IS FUSED TO THE 5' REGION OF THE BCR GENE. EXPRESSION OF THE HYBRID BCR-ABL GENE IS, THEREFORE, REGULATED BY THE BCR PROMOTER. IN MOST CASES OF CML, ONE OF THE TWO ABL PROMOTERS (PA) IS NESTED WITHIN THE BCR-ABL TRANSCRIPTIONAL UNIT AND SHOULD BE ABLE TO TRANSCRIBE THE TYPE IA 6-KB NORMAL ABL MRNA FROM THE PHILADELPHIA CHROMOSOME. HOWEVER, WE HAVE FOUND THAT THE 6-KB TRANSCRIPT IS PRESENT ONLY IN CML CELL LINES CONTAINING A NORMAL ABL ALLELE AND THAT THE APPARENT INACTIVATION OF THE NESTED PA PROMOTER IS ASSOCIATED WITH ALLELE-SPECIFIC METHYLATION. FURTHERMORE, WE HAVE NOTICED THAT THE PA PROMOTER IS CONTAINED WITHIN A CPG ISLAND AND UNDERGOES PROGRESSIVE DE NOVO METHYLATION IN THE COURSE OF THE DISEASE. THIS IS ATTESTED TO BY THE FACT THAT DNA SAMPLES FROM CML PATIENTS THAT ARE METHYLATION-FREE AT THE TIME OF DIAGNOSIS INVARIABLY BECOME METHYLATED IN ADVANCED CML. SINCE TUMOR PROGRESSION IN CML CANNOT ALWAYS BE INFERRED FROM THE CLINICAL PRESENTATION, ASSESSMENT OF DE NOVO CPG METHYLATION MAY PROVE TO BE OF CRITICAL VALUE IN MANAGEMENT OF THE DISEASE. IT COULD HERALD BLASTIC TRANSFORMATION AT A STAGE WHEN BONE MARROW TRANSPLANTATION, THE ONLY POTENTIALLY CURATIVE THERAPEUTIC PROCEDURE IN CML, IS STILL EFFECTIVE. 1994