1 2441 108 EPIGENETIC SILENCING OF TUMOR SUPPRESSOR MIR-3151 CONTRIBUTES TO CHINESE CHRONIC LYMPHOCYTIC LEUKEMIA BY CONSTITUTIVE ACTIVATION OF MADD/ERK AND PIK3R2/AKT SIGNALING PATHWAYS. WE HYPOTHESIZE THAT MIR-3151, LOCALIZED TO A GWAS-IDENTIFIED CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) RISK LOCUS (8Q22.3), IS A TUMOR SUPPRESSOR MIRNA SILENCED BY PROMOTER DNA METHYLATION IN CLL. THE PROMOTER OF MIR-3151 WAS METHYLATED IN 5/7 (71%) CLL CELL LINES, 30/98 (31%) DIAGNOSTIC PRIMARY SAMPLES, BUT NOT NORMAL CONTROLS. METHYLATION OF MIR-3151 CORRELATED INVERSELY WITH EXPRESSION. TREATMENT WITH 5-AZA-2'-DEOXYCYTIDINE LED TO PROMOTER DEMETHYLATION AND MIR-3151 RE-EXPRESSION. LUCIFERASE ASSAY CONFIRMED MAP-KINASE ACTIVATING DEATH DOMAIN (MADD) AND PHOSPHOINOSITIDE-3-KINASE, REGULATORY SUBUNIT 2 (PIK3R2) AS DIRECT TARGETS OF MIR-3151. MOREOVER, RESTORATION OF MIR-3151 RESULTED IN INHIBITION OF CELLULAR PROLIFERATION AND ENHANCED APOPTOSIS, REPRESSION OF MADD AND PIK3R2, DOWNREGULATION OF MEK/ERK AND PI3K/AKT SIGNALING, AND REPRESSION OF MCL1. LASTLY, MIR-3151 METHYLATION WAS SIGNIFICANTLY ASSOCIATED WITH METHYLATION OF MIR-203 AND MIR-34B/C IN PRIMARY CLL SAMPLES. THEREFORE, THIS STUDY SHOWED THAT MIR-3151 IS A TUMOR SUPPRESSIVE MIRNA FREQUENTLY HYPERMETHYLATED AND HENCE SILENCED IN CLL. MIR-3151 SILENCING BY DNA METHYLATION PROTECTED CLL CELLS FROM APOPTOSIS THROUGH OVER-EXPRESSION OF ITS DIRECT TARGETS MADD AND PIK3R2, HENCE CONSTITUTIVE ACTIVATION OF MEK/ERK AND PI3K/AKT SIGNALING RESPECTIVELY, AND CONSEQUENTLY OVER-EXPRESSION OF MCL1.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
2 2431  39 EPIGENETIC SILENCING OF MIR-26A1 IN CHRONIC LYMPHOCYTIC LEUKEMIA AND MANTLE CELL LYMPHOMA: IMPACT ON EZH2 EXPRESSION. DOWNREGULATION OF MIR26A1 HAS BEEN REPORTED IN VARIOUS B-CELL MALIGNANCIES; HOWEVER, THE MECHANISM BEHIND ITS DEREGULATION REMAINS LARGELY UNKNOWN. WE INVESTIGATED MIR26A1 METHYLATION AND EXPRESSION LEVELS IN A WELL-CHARACTERIZED SERIES OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND MANTLE CELL LYMPHOMA (MCL). FROM 450K METHYLATION ARRAYS, WE FIRST OBSERVED MIR26A1 (CG26054057) AS UNIFORMLY HYPERMETHYLATED IN MCL (N = 24) (ALL >75%), WHILE CLL (N = 18) SHOWED DIFFERENTIAL METHYLATION BETWEEN PROGNOSTIC SUBGROUPS. EXTENDED ANALYSIS USING PYROSEQUENCING CONFIRMED OUR FINDINGS AND REAL-TIME QUANTITATIVE PCR VERIFIED LOW MIR26A1 EXPRESSION IN BOTH CLL (N = 70) AND MCL (N = 38) COMPARED TO NORMAL B-CELLS. NOTABLY, THE LEVEL OF MIR26A1 METHYLATION PREDICTED OUTCOME IN CLL, WITH HIGHER LEVELS SEEN IN POOR-PROGNOSTIC, IGHV-UNMUTATED CLL. SINCE EZH2 WAS RECENTLY REPORTED AS A TARGET FOR MIR26A1, WE ANALYZED THE EXPRESSION LEVELS OF BOTH MIR26A1 AND EZH2 IN PRIMARY CLL SAMPLES AND OBSERVED AN INVERSE CORRELATION. BY OVEREXPRESSION OF MIR26A1 IN CLL AND MCL CELL LINES, REDUCED EZH2 PROTEIN LEVELS WERE OBSERVED USING BOTH WESTERN BLOT AND FLOW CYTOMETRY. IN CONTRAST, METHYL-INHIBITOR TREATMENT LED TO UPREGULATED MIR26A1 EXPRESSION WITH A PARALLEL DECREASE OF EZH2 EXPRESSION. FINALLY, INCREASED LEVELS OF APOPTOSIS WERE OBSERVED IN MIR26A1-OVEREXPRESSING CELL LINES, FURTHER UNDERSCORING THE FUNCTIONAL RELEVANCE OF MIR26A1. IN SUMMARY, WE PROPOSE THAT EPIGENETIC SILENCING OF MIR26A1 IS REQUIRED FOR THE MAINTENANCE OF INCREASED LEVELS OF EZH2, WHICH IN TURN TRANSLATE INTO A WORSE OUTCOME, AS SHOWN IN CLL, HIGHLIGHTING MIR26A1 AS A TUMOR SUPPRESSOR MIRNA.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                  
3  494  29 ASSESSMENT OF PROMOTER METHYLATION IDENTIFIES PTCH AS A PUTATIVE TUMOR-SUPPRESSOR GENE IN HUMAN CLL. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF NEOPLASTIC LYMPHOCYTES, INDICATING DISRUPTION OF APOPTOSIS. PATIENTS AND METHODS: DIFFERENTIAL METHYLATION HYBRIDIZATION ANALYSIS WAS PERFORMED TO IDENTIFY NOVEL TARGET GENES SILENCED BY CPG ISLAND METHYLATION IN PATIENTS WITH CLL. RESULTS: PATCHED (PTCH), A TUMOR-SUPPRESSOR GENE, WAS FOUND TO BE FREQUENTLY METHYLATED IN CLL SAMPLES COMPARED TO SAMPLES DERIVED FROM HEALTHY INDIVIDUALS. DE NOVO METHYLATION OF A CPG ISLAND REGION LOCATED UPSTREAM OF PTCH EXON 1 WAS CONFIRMED BY PYROSEQUENCING IN 17/37 (46%) OF PERIPHERAL BLOOD MONONUCLEAR CELLS OF PATIENTS WITH CLL, BUT IN NONE ISOLATED FROM SEVEN HEALTHY INDIVIDUALS. NO ASSOCIATION WAS FOUND BETWEEN PTCH HYPERMETHYLATION AND CURRENTLY USED PROGNOSTIC CLL FACTORS. CONCLUSION: OUR INVESTIGATION SUGGESTS THAT EPIGENETIC SILENCING OF PTCH IS A MECHANISM CONTRIBUTING TO CLL TUMORIGENESIS.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
4 2127  57 EPIGENETIC INACTIVATION OF MIR-9 FAMILY MICRORNAS IN CHRONIC LYMPHOCYTIC LEUKEMIA--IMPLICATIONS ON CONSTITUTIVE ACTIVATION OF NFKAPPAB PATHWAY. BACKGROUND: THE MIR-9 FAMILY MICRORNAS HAVE BEEN IDENTIFIED AS A TUMOR SUPPRESSOR MIRNA IN CANCERS. WE POSTULATED THAT MIR-9-1, MIR-9-2 AND MIR-9-3 MIGHT BE INACTIVATED BY DNA HYPERMETHYLATION IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). METHODS: METHYLATION OF MIR-9-1, MIR-9-2 AND MIR-9-3 WAS STUDIED IN EIGHT NORMAL CONTROLS INCLUDING NORMAL BONE MARROW, BUFFY COAT, AND CD19-SORTED PERIPHERAL BLOOD B-CELLS FROM HEALTHY INDIVIDUALS, SEVEN CLL CELL LINES, AND SEVENTY-EIGHT DIAGNOSTIC CLL SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. RESULTS: THE PROMOTERS OF MIR-9-3 AND MIR-9-1 WERE BOTH UNMETHYLATED IN NORMAL CONTROLS, BUT METHYLATED IN FIVE (71.4%) AND ONE OF SEVEN CLL CELL LINES RESPECTIVELY. HOWEVER, MIR-9-2 PROMOTER WAS METHYLATED IN NORMAL CONTROLS INCLUDING CD19 + VE B-CELLS, HENCE SUGGESTIVE OF A TISSUE-SPECIFIC BUT NOT TUMOR-SPECIFIC METHYLATION, AND THUS NOT FURTHER STUDIED. DIFFERENT MSP STATUSES OF MIR-9-3, INCLUDING COMPLETE METHYLATION, PARTIAL METHYLATION, AND COMPLETE UNMETHYLATION, WERE VERIFIED BY QUANTITATIVE BISULFITE METHYLATION ANALYSIS. 5-AZA-2'-DEOXYCYTIDINE TREATMENT RESULTED IN MIR-9-3 PROMOTER DEMETHYLATION AND RE-EXPRESSION OF PRI-MIR-9-3 IN I83-E95 AND WAC3CD5+ CELLS, WHICH WERE HOMOZYGOUSLY METHYLATED FOR MIR-9-3. MOREOVER, OVEREXPRESSION OF MIR-9 LED TO SUPPRESSED CELL PROLIFERATION AND ENHANCED APOPTOSIS TOGETHER WITH DOWNREGULATION OF NFKAPPAB1 IN I83-E95 CELLS, SUPPORTING A TUMOR SUPPRESSOR ROLE OF MIR-9-3 IN CLL. IN PRIMARY CLL SAMPLES, MIR-9-3 WAS DETECTED IN 17% AND MIR-9-1 METHYLATION IN NONE OF THE PATIENTS AT DIAGNOSIS. MOREOVER, MIR-9-3 METHYLATION WAS ASSOCIATED WITH ADVANCED RAI STAGE (>/= STAGE 2) (P = 0.04). CONCLUSIONS: OF THE MIR-9 FAMILY, MIR-9-3 IS A TUMOR SUPPRESSOR MIRNA RELATIVELY FREQUENTLY METHYLATED, AND HENCE SILENCED IN CLL; WHEREAS MIR-9-1 METHYLATION IS RARE IN CLL. THE ROLE OF MIR-9-3 METHYLATION IN THE CONSTITUTIVE ACTIVATION OF NFKAPPAB SIGNALING PATHWAY IN CLL WARRANTS FURTHER STUDY.	2013	
                                                                                    
5 4221  38 METHYLATION AND SILENCING OF PROTEIN TYROSINE PHOSPHATASE RECEPTOR TYPE O IN CHRONIC LYMPHOCYTIC LEUKEMIA. PURPOSE: PREVIOUS STUDIES IN OUR LABORATORY HAVE SHOWN THE PROGRESSIVE METHYLATION AND SUPPRESSION OF THE GENE ENCODING PROTEIN TYROSINE PHOSPHATASE, PTPRO, IN THE LIVERS OF RATS FED A METHYL-DEFICIENT DIET THAT INDUCES HEPATOCARCINOGENESIS. SUBSEQUENTLY, WE OBSERVED THE METHYLATION OF PTPRO IN PRIMARY HUMAN LUNG TUMORS AND ALSO SHOWED ITS POTENTIAL TUMOR SUPPRESSOR CHARACTERISTICS. THE PRESENT STUDY WAS UNDERTAKEN TO INVESTIGATE WHETHER THE TRUNCATED FORM OF PTPRO (PTPROT), SPECIFICALLY EXPRESSED IN NAIVE B LYMPHOCYTES, WAS ALSO METHYLATED AND SUPPRESSED IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), A DISEASE GENERALLY AFFECTING B LYMPHOCYTES. EXPERIMENTAL DESIGN AND RESULTS: INITIAL SCREENING SHOWED THAT 60% OF THE 52 CLL SAMPLES ANALYZED USING METHYLATION-SPECIFIC PCR ASSAY WERE METHYLATED COMPARED WITH B LYMPHOCYTES FROM NORMAL INDIVIDUALS, WHICH WERE NOT METHYLATED. THE EXPRESSION OF PTPROT, AS MEASURED BY SEMIQUANTITATIVE REVERSE TRANSCRIPTION-PCR, INVERSELY CORRELATED WITH METHYLATION IN THE FEW SAMPLES TESTED. ANALYSIS OF ADDITIONAL SAMPLES (N = 50) BY COMBINED BISULFITE RESTRICTION ANALYSIS SHOWED THAT THE PTPRO CPG ISLAND WAS METHYLATED IN 82% OF PATIENTS WITH CLL COMPARED WITH B LYMPHOCYTES FROM NORMAL INDIVIDUALS. FURTHERMORE, OVERALL EXPRESSION OF PTPRO WAS REDUCED IN CLL RELATIVE TO NORMAL LYMPHOCYTES. THE PTPRO GENE WAS ALSO SUPPRESSED BY METHYLATION IN THE CLL CELL LINE WAC3CD5, WHERE IT COULD BE REACTIVATED UPON TREATMENT WITH THE DNA HYPOMETHYLATING AGENT 5-AZAC. ECTOPIC EXPRESSION OF PTPROT IN A NONEXPRESSING CELL LINE INCREASED GROWTH INHIBITION WITH FLUDARABINE TREATMENT, A THERAPY COMMONLY USED FOR CLL. CONCLUSION: THIS STUDY REVEALS THE POTENTIAL ROLE OF PTPRO METHYLATION AND SILENCING IN CLL TUMORIGENESIS AND ALSO PROVIDES A NOVEL MOLECULAR TARGET IN THE EPIGENETIC THERAPY.	2007	
                                                                                                                                                                                                                                                                                             
6 2128  36 EPIGENETIC INACTIVATION OF PLCD1 IN CHRONIC MYELOID LEUKEMIA. PHOSPHOLIPASE C DELTA1 (PLCD1), IS LOCATED AT THE IMPORTANT TUMOR SUPPRESSOR LOCUS 3P22. IT ENCODES AN ENZYME THAT MEDIATES REGULATORY SIGNALING OF ENERGY METABOLISM, CALCIUM HOMEOSTASIS AND INTRACELLULAR MOVEMENTS. PLCD1 HAS BEEN STUDIED IN SOME HUMAN SOLID TUMORS RELATING TO THE CPG ISLAND METHYLATION OF THE GENE PROMOTER AS A FUNCTIONAL TUMOR SUPPRESSOR. HOWEVER, NO SUCH INFORMATION IS AVAILABLE IN CHRONIC MYELOID LEUKEMIA (CML). IN THIS STUDY, WE INVESTIGATED PLCD1 EXPRESSION IN THE CML K562 CELL LINE (0/1) AND 15% (2/13) OF BONE MARROW MONONUCLEAR CELLS WITH CML BY USING SEMI-QUANTITATIVE PCR. THE CPG ISLAND (CGI) METHYLATION STATUS OF THE PLCD1 PROMOTER WAS DETECTED IN K562 (0/1) AND 56% (23/41) OF CML PATIENTS BY METHYLATION-SPECIFIC PCR (MSP), BUT NOT IN THE NORMAL ADULT BONE MARROW MONONUCLEAR CELLS. FURTHERMORE, THE DNA DEMETHYLATION AGENT 5'-AZA-2'DEOXYCYTIDINE RESTORED THE EXPRESSION OF PLCD1 IN K562 CELLS. FUNCTIONAL STUDIES SHOWED THAT ECTOPIC EXPRESSION OF PLCD1 IN K562 CELLS WAS ABLE TO DRAMATICALLY INHIBIT THEIR COLONY FORMATION AND INDUCE CELL CYCLE G1 ARREST, SUGGESTING THAT PLCD1 ACTS AS A FUNCTIONAL TUMOR SUPPRESSOR AND MAY SERVE AS A BIOMARKER FOR POSSIBLE EARLY DETECTION AND PROGNOSIS OF CML.	2012	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
7 2432  39 EPIGENETIC SILENCING OF MIR-708 ENHANCES NF-KAPPAB SIGNALING IN CHRONIC LYMPHOCYTIC LEUKEMIA. MICRORNAS (MIRNAS) ARE POST-TRANSCRIPTIONAL REGULATORS OF GENE EXPRESSION AND THEIR DEREGULATION IS INVOLVED IN TUMOR DEVELOPMENT. EPIGENETIC GENE SILENCING IN CANCER BY DNA METHYLATION CONTRIBUTES TO THE SILENCING OF TUMOR-SUPPRESSOR GENES, INCLUDING MIRNAS. WE HAVE RECENTLY SHOWN THAT THE PROMOTER OF MIR-708 IS ABERRANTLY METHYLATED IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). TO CHARACTERIZE THE MOLECULAR SIGNALING NETWORKS THAT ARE INFLUENCED BY MIR-708, WE PERFORMED A LUCIFERASE-BASED SCREEN EVALUATING THE EFFECTS OF ECTOPIC MIR-708 EXPRESSION ON LEUKEMIA-RELEVANT SIGNALING PATHWAYS. WE FOUND THAT MIR-708 STRONGLY REPRESSED NF-KAPPAB SIGNALING, A PATHWAY KNOWN TO BE DEREGULATED IN CLL. AMONG THE PREDICTED MIR-708 TARGETS WAS IKKBETA (INHIBITOR OF KAPPA LIGHT POLYPEPTIDE GENE ENHANCER IN B CELLS, KINASE-BETA/IKBKB), A KEY KINASE FACILITATING NF-KAPPAB SIGNALING. WE VALIDATED THE INTERACTION OF MIR-708 WITH THE 3'-UNTRANSLATED REGION OF IKKBETA AND FOUND THAT MIR-708 OVEREXPRESSION REPRESSES ENDOGENOUS IKKBETA. PHOSPHORYLATION OF THE IKKBETA TARGET IKAPPABALPHA AND EXPRESSION OF KNOWN NF-KAPPAB TARGET GENES WERE IMPAIRED BY MIR-708. FURTHERMORE, WE IDENTIFIED AN ENHANCER REGION DOWNSTREAM OF THE MIR-708 PROMOTER THAT DISPLAYS A DISTINCT DNA METHYLATION STATUS IN CLL. HIGH ENHANCER METHYLATION IS SIGNIFICANTLY CORRELATED WITH LOWER MIR-708 EXPRESSION AND IS PREDOMINANTLY FOUND IN PATIENTS WITH POOR PROGNOSIS AND SHORTER TIME TO TREATMENT. THESE RESULTS DEMONSTRATE THAT MIR-708 REGULATES THE NF-KAPPAB PATHWAY BY TARGETING IKKBETA, AND THAT METHYLATION OF A KEY ENHANCER REGION CONTRIBUTES TO ITS SUPPRESSION IN CLL.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
8 3168  25 GTPASE REGULATOR ASSOCIATED WITH THE FOCAL ADHESION KINASE (GRAF) TRANSCRIPT WAS DOWN-REGULATED IN PATIENTS WITH MYELOID MALIGNANCIES. BACKGROUND: GTPASE REGULATOR ASSOCIATED WITH THE FOCAL ADHESION KINASE (GRAF), A PUTATIVE TUMOR SUPPRESSOR GENE, IS FOUND INACTIVATED IN HEMATOPOIETIC MALIGNANCIES BY EITHER GENETIC OR EPIGENETIC ABNORMALITIES. HOWEVER, THE EXPRESSION LEVEL OF GRAF GENE HAS NOT YET BEEN STUDIED IN LEUKEMIA. THE AIM OF THIS STUDY WAS TO INVESTIGATE THE EXPRESSION LEVEL OF GRAF GENE IN THOSE PATIENTS WITH MYELOID MALIGNANCIES INCLUDING ACUTE MYELOID LEUKEMIA (AML), MYELODYSPLASTIC SYNDROME (MDS) AND CHRONIC MYELOID LEUKEMIA (CML). METHODS: THE EXPRESSION LEVELS OF GRAF TRANSCRIPT WERE DETERMINED IN 94 PATIENTS USING REAL-TIME QUANTITATIVE PCR (RQ-PCR). CLINICAL AND LABORATORY DATA OF THESE PATIENTS WERE COLLECTED AND ANALYZED. RESULTS: THE SIGNIFICANTLY DECREASED LEVEL OF GRAF TRANSCRIPT WAS OBSERVED IN THREE MYELOID MALIGNANCIES COMPARED TO CONTROLS. WITHIN AML, THERE WAS NO DIFFERENCE IN THE LEVEL OF GRAF TRANSCRIPT AMONG DIFFERENT FAB SUBTYPES (P > 0.05). DIFFERENCE WAS NOT OBSERVED IN THE AMOUNT OF GRAF MRNA BETWEEN CML AT CHRONIC PHASE AND CONTROLS. AS CML PROGRESSED, GRAF TRANSCRIPT SIGNIFICANTLY DECREASED. IN MDS, THREE CASES WITH 5Q DELETION HAD LOWER GRAF TRANSCRIPT THAN FOUR WITHOUT 5Q DELETION (MEDIAN 0.76 VS 2.99) (P > 0.05). CONCLUSION: OUR RESULTS DEMONSTRATE THAT THE GRAF TRANSCRIPT IS DECREASED IN MYELOID MALIGNANCIES.	2010	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
9 2304  29 EPIGENETIC REGULATION OF CATHEPSIN L EXPRESSION IN CHRONIC MYELOID LEUKAEMIA. THE EXPRESSION AND SIGNIFICANCE OF CATHEPSIN L (CTSL) HAS BEEN EXTENSIVELY STUDIED IN SOLID TUMOURS. HOWEVER NO SUCH INFORMATION IN CHRONIC MYELOID LEUKAEMIA (CML) WAS AVAILABLE. WE INVESTIGATED THE ACTIVITY AND EXPRESSION OF THIS PROTEASE IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) OF 47 ADULT CML PATIENTS. THIRTY ADULTS SUFFERING FROM SYSTEMIC DISEASES AND 50 HEALTHY VOLUNTEERS SERVED AS CONTROLS. THE MRNA LEVELS OF CTSL, ITS SPECIFIC ENDOGENOUS INHIBITOR CYSTATIN C AND TRANSCRIPTIONAL UP-REGULATOR VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) WERE QUANTITATED BY REAL-TIME QPCR. CTSL PROTEASE ACTIVITY AND ITS MRNA EXPRESSION WERE SIGNIFICANTLY HIGHER IN CML CHRONIC PHASE (CP) PATIENTS COMPARED TO CML ACCELERATED PHASE/BLAST CRISIS (AP/BC) PATIENTS AND CONTROLS (P</= 0.001). VEGF WHOSE EXPRESSION WAS MOST PRONOUNCED IN CP AND DECLINED (P</= 0.001) IN THE ADVANCED PHASES OF THE MALIGNANCY EXHIBITED A STRONG POSITIVE CORRELATION WITH CTSL EXPRESSION (R= 0.97; P</= 0.001). CYSTATIN C EXPRESSION WAS SIGNIFICANTLY LOWER (P</= 0.001) IN CML AND DISPLAYED INVERSE CORRELATION WITH CTSL (R=-0.713; P</= 0.001) ACTIVITY. CTSL PROMOTER WAS SIGNIFICANTLY HYPOMETHYLATED IN CML CP COMPARED TO CML AP/BC PATIENTS AS WELL AS CONTROLS. K562, A BC CML CELL LINE DISPLAYED CTSL ACTIVITY, EXPRESSION AND METHYLATION STATUS OF CTSL PROMOTER THAT WAS COMPARABLE TO CML AP/BC PATIENTS. TREATMENT OF THESE CELLS OR PBMCS ISOLATED FROM CML AP/BC PATIENTS WITH 5'-AZA-CYTIDINE RESULTED IN A DRAMATIC INCREASE IN CSTL ACTIVITY AND/OR EXPRESSION THEREBY DEMONSTRATING THE ROLE OF PROMOTER METHYLATION IN THE STAGE SPECIFIC EXPRESSION OF CTSL IN CML. DIFFERENTIAL EXPRESSION OF CTSL IN CML AT VARIOUS STAGES OF MALIGNANCY MAY PROVE USEFUL IN IDENTIFICATION OF THE HIGH-RISK PATIENTS THEREBY FACILITATING BETTER MANAGEMENT OF DISEASE.	2011	
                                                                                                                                                                                                                                                                                                                          
10  145  29 ABERRANT DNA METHYLATION STATUS AND MRNA EXPRESSION LEVEL OF SMG1 GENE IN CHRONIC MYELOID LEUKEMIA: A CASE-CONTROL STUDY. OOBJECTIVE: CHRONIC MYELOID LEUKEMIA (CML) IS A MYELOPROLIFERATIVE MALIGNANCY WITH DIFFERENT STAGES. ABERRANT EPIGENETIC MODIFICATIONS, SUCH AS DNA METHYLATION, HAVE BEEN INTRODUCED AS A SIGNATURE FOR DIVERSE CANCERS WHICH ALSO PLAYS A CRUCIAL ROLE IN CML PATHOGENESIS AND DEVELOPMENT. SUPPRESSOR WITH MORPHOGENETIC EFFECT ON GENITALIA (SMG1) GENE RECENTLY HAS BEEN BROUGHT TO THE SPOTLIGHT AS A POTENT TUMOR SUPPRESSOR GENE THAT CAN BE SUPPRESSED BY TUMORS FOR FURTHER PROGRESS. THE PRESENT STUDY AIMS TO INVESTIGATE SMG1 STATUS IN CML PATIENTS. MATERIALS AND METHODS: IN THIS CASE-CONTROL STUDY, PERIPHERAL BLOOD FROM 30 PATIENTS WITH DIFFERENT PHASES OF CML [NEW CASE (N)=10, COMPLETE MOLECULAR REMISSION (CMR)=10, BLASTIC PHASE (BP)=10] AND 10 HEALTHY SUBJECTS WERE COLLECTED. METHYLATION STATUS AND EXPRESSION LEVEL OF SMG1 GENE PROMOTER WAS ASSESSED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) AND QUANTITATIVE REVERSE-TRANSCRIPTION PCR, RESPECTIVELY. RESULTS: MSP RESULTS OF SMG1 GENE PROMOTOR IN THE NEW CASE GROUP WERE METHYLATED (60% METHYLATED, 30% HEMIMETHYLATED AND 10% UNMETHYLATED). ALL CMR AND CONTROL GROUP PATIENTS WERE UNMETHYLATED IN THE SMG1 GENE PROMOTER. IN THE BP GROUP, METHYLATED SMG1 PROMOTER WAS SEEN (50% OF PATIENTS HAD A METHYLATED STATUS AND 50% HAD HEMIMETHYLATED STATUS). IN COMPARISON WITH THE HEALTHY SUBJECTS, EXPRESSION LEVEL OF SMG1 IN THE NEW CASE GROUP WAS DECREASED (P<0.01); IN THE CMR GROUP AND BP-CML GROUPS, IT WAS INCREASED (P<0.05). NO SIGNIFICANT CORRELATION BETWEEN PATIENTS' HEMATOLOGICAL FEATURES AND SMG1 METHYLATION WAS SEEN. CONCLUSION: OUR RESULTS DEMONSTRATED THAT ABERRANT METHYLATION OF SMG1 OCCURRED IN CML PATIENTS AND IT HAD A SIGNIFICANT ASSOCIATION WITH SMG1 EXPRESSION. SMG1 GENE PROMOTER SHOWED DIVERSE METHYLATED STATUS AND SUBSEQUENT EXPRESSION LEVELS IN DIFFERENT PHASES OF CML. THESE FINDINGS SUGGESTED POSSIBLE PARTICIPATION OF SMG1 SUPPRESSION IN THE CML PATHOGENESIS.	2022	
                                                                                                                                          
11 2763  30 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS.	2010	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
12 1334  35 DEREGULATION OF AIOLOS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS THAT ARE RESISTANT TO APOPTOSIS. AIOLOS, A MEMBER OF THE IKAROS FAMILY OF ZINC-FINGER TRANSCRIPTION FACTORS, PLAYS AN IMPORTANT ROLE IN THE CONTROL OF MATURE B LYMPHOCYTE DIFFERENTIATION AND MATURATION. IN THIS STUDY, WE SHOWED THAT AIOLOS EXPRESSION IS UP-REGULATED IN B-CLL CELLS. THIS OVEREXPRESSION DOES NOT IMPLICATE ISOFORM IMBALANCE OR DISTURB AIOLOS SUBCELLULAR LOCALIZATION. THE CHROMATIN STATUS AT THE AIOLOS PROMOTER IN CLL IS DEFINED BY THE DEMETHYLATION OF DNA AND AN ENRICHMENT OF EUCHROMATIN ASSOCIATED HISTONE MARKERS, SUCH AS THE DIMETHYLATION OF THE LYSINE 4 ON HISTONE H3. THESE EPIGENETIC MODIFICATIONS SHOULD ALLOW ITS UPSTREAM EFFECTORS, SUCH AS NUCLEAR FACTOR-KAPPAB, CONSTITUTIVELY ACTIVATED IN CLL, TO GAIN ACCESS TO PROMOTER, RESULTING UP-REGULATION OF AIOLOS. TO DETERMINE THE CONSEQUENCES OF AIOLOS DEREGULATION IN CLL, WE ANALYZED THE EFFECTS OF AIOLOS OVEREXPRESSION OR DOWN-REGULATION ON APOPTOSIS. AIOLOS IS INVOLVED IN CELL SURVIVAL BY REGULATING THE EXPRESSION OF SOME BCL-2 FAMILY MEMBERS. OUR RESULTS STRONGLY SUGGEST THAT AIOLOS DEREGULATION BY EPIGENETIC MODIFICATIONS MAY BE A HALLMARK OF CLL.	2011	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
13 5229  37 PRO-APOPTOTIC TP53 HOMOLOG TAP63 IS REPRESSED VIA EPIGENETIC SILENCING AND B-CELL RECEPTOR SIGNALLING IN CHRONIC LYMPHOCYTIC LEUKAEMIA. CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) IS AN ACCUMULATIVE DISORDER MARKED BY DEFICIENT APOPTOSIS. THE TP53 HOMOLOG TAP63 PROMOTES APOPTOSIS AND CHEMOSENSITIVITY IN SOLID TUMOURS AND ITS DEREGULATION MAY CONTRIBUTE TO CLL CELL SURVIVAL. WE FOUND THAT TAP63ALPHA WAS THE MOST PREVALENT TP63 ISOFORM IN CLL. COMPARED TO HEALTHY B CELLS, TAP63 MRNA WAS REPRESSED IN 55.7% OF CLL SAMPLES. TP63 PROMOTER METHYLATION WAS HIGH IN CLL AND INVERSELY CORRELATED WITH TP63 PROTEIN EXPRESSION IN B-CELL LYMPHOMA CELL LINES. SIRNA-MEDIATED KNOCKDOWN OF TP63 RESULTED IN PARTIAL PROTECTION FROM SPONTANEOUS APOPTOSIS ACCOMPANIED BY REDUCTIONS IN PMAIP1 (NOXA), BBC3 (PUMA), AND BAX MRNA IN CLL CELLS AND INCREASED PROLIFERATION OF RAJI LYMPHOMA CELLS. TAP63 MRNA LEVELS WERE HIGHER IN CLL WITH UNMUTATED IGHV. B-CELL RECEPTOR (BCR) ENGAGEMENT LED TO REPRESSION OF TP63 MRNA EXPRESSION IN MALIGNANT B CELLS, WHILE PHARMACOLOGICAL INHIBITION OF BCR SIGNALLING PREVENTED TP63 DOWNREGULATION. MIR21, KNOWN TO TARGET TAP63, CORRELATED INVERSELY WITH TAP63 EXPRESSION IN CLL, AND BCR-MEDIATED DOWNREGULATION OF TP63 WAS ACCOMPANIED BY MIR21 UPREGULATION IN MOST CLL SAMPLES. OUR DATA ILLUSTRATE THE PRO-APOPTOTIC FUNCTION OF TP63, PROVIDE INSIGHTS INTO THE MECHANISMS OF BCR-TARGETING AGENTS, AND ESTABLISH A RATIONALE FOR DESIGNING NOVEL APPROACHES TO INDUCE TP63 IN CLL AND B-CELL LYMPHOMA.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
14 3114  31 GERMLINE ALLELE-SPECIFIC EXPRESSION OF DAPK1 IN CHRONIC LYMPHOCYTIC LEUKEMIA. WE PREVIOUSLY REPORTED A RARE GERMLINE VARIANT (C.1-6531) THAT RESULTED IN ALLELE-SPECIFIC EXPRESSION (ASE) OF DEATH-ASSOCIATED PROTEIN KINASE 1 (DAPK1) AND PREDISPOSITION TO CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). WE INVESTIGATED A COHORT OF CLL PATIENTS LACKING THIS MUTATION FOR THE PRESENCE OF ASE OF DAPK1. WE DEVELOPED A NOVEL STRATEGY THAT COMBINES SINGLE-NUCLEOTIDE PRIMER EXTENSION (SNUPE) WITH MALDI-TOF MASS SPECTROMETRY, AND DETECTED GERMLINE DAPK1 ASE IN 17 OUT OF 120 (14.2%) CLL PATIENTS ASSOCIATED WITH A TREND TOWARDS YOUNGER AGE AT DIAGNOSIS. ASE WAS ABSENT IN 63 HEALTHY CONTROLS. GERMLINE CELLS OF CLL PATIENTS WITH ASE SHOWED INCREASED LEVELS OF DNA METHYLATION IN THE PROMOTER REGION, HOWEVER, NEITHER GENETIC NOR FURTHER EPIGENETIC ABERRATIONS COULD BE IDENTIFIED IN THE DAPK1 5' UPSTREAM REGULATORY REGION, WITHIN DISTINCT EXONS OR IN THE 3'-UTR. WE IDENTIFIED B-LYMPHOID MALIGNANCY RELATED CELL LINE MODELS HARBORING ALLELIC IMBALANCE AND FOUND THAT ALLELE-SPECIFIC METHYLATION IN DAPK1 IS ASSOCIATED WITH ASE. OUR DATA INDICATE THAT ASE AT THE DAPK1 GENE LOCUS IS A RECURRENT EVENT, MEDIATED BY EPIGENETIC MECHANISMS AND POTENTIALLY PREDISPOSING TO CLL.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
15 2327  38 EPIGENETIC REGULATION OF HUMAN CANCER/TESTIS ANTIGEN GENE, HAGE, IN CHRONIC MYELOID LEUKEMIA. BACKGROUND AND OBJECTIVES: CANCER TESTIS ANTIGENS (CTA) PROVIDE ATTRACTIVE TARGETS FOR CANCER-SPECIFIC IMMUNOTHERAPY. ALTHOUGH CTA GENES ARE EXPRESSED IN SOME NORMAL TISSUES, SUCH AS THE TESTIS, THIS IMMUNOLOGICALLY PROTECTED SITE LACKS MHC I EXPRESSION AND AS SUCH, DOES NOT PRESENT SELF ANTIGENS TO T CELLS. TO DATE, CTA GENES HAVE BEEN SHOWN TO BE EXPRESSED IN A RANGE OF SOLID TUMORS VIA DEMETHYLATION OF THEIR PROMOTER CPG ISLANDS, BUT RARELY IN CHRONIC MYELOID LEUKEMIA (CML) OR OTHER HEMATOLOGIC MALIGNANCIES. DESIGN AND METHODS: IN THIS STUDY, THE METHYLATION STATUS OF THE HAGE CTA GENE PROMOTER WAS ANALYZED BY QUANTITATIVE METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) AND SEQUENCING IN FOUR PHILADELPHIA-POSITIVE CELL LINES (TCC-S, K562, KU812 AND KYO-1) AND IN CML SAMPLES TAKEN FROM PATIENTS IN CHRONIC PHASE (CP N=215) OR BLAST CRISIS (BC N=47). HAGE EXPRESSION WAS ASSESSED BY QUANTITATIVE REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION. RESULTS: THE TCC-S CELL LINE SHOWED DEMETHYLATION OF HAGE THAT WAS ASSOCIATED WITH OVER-EXPRESSION OF THIS GENE. HAGE HYPOMETHYLATION WAS SIGNIFICANTLY MORE FREQUENT IN BC (46%) THAN IN CP (22%) (P=0.01) AND WAS CORRELATED WITH HIGH EXPRESSION LEVELS OF HAGE TRANSCRIPTS (P<0.0001). OF NOTE, IN CP-CML, EXTENSIVE HAGE HYPOMETHYLATION WAS ASSOCIATED WITH POORER PROGNOSIS IN TERMS OF CYTOGENETIC RESPONSE TO INTERFERON (P=0.01) OR IMATINIB (P=0.01), MOLECULAR RESPONSE TO IMATINIB (P=0.003) AND PROGRESSION-FREE SURVIVAL (P=0.05). INTERPRETATIONS AND CONCLUSION: THE METHYLATION STATUS OF THE HAGE PROMOTER DIRECTLY CORRELATES WITH ITS EXPRESSION IN BOTH CML CELL LINES AND PATIENTS AND IS ASSOCIATED WITH ADVANCED DISEASE AND POOR OUTCOME.	2007	
                                                                                                                                                                                                                                                                                                                                                                                                                                 
16 2453  29 EPIGENETIC SUPPRESSION OF THE IMMUNOREGULATOR MZB1 IS ASSOCIATED WITH THE MALIGNANT PHENOTYPE OF GASTRIC CANCER. PREDICTION OF TUMOR RECURRENCE AFTER CURATIVE RESECTION IS CRITICAL FOR DETERMINING THE PROGNOSIS OF PATIENTS WITH GASTRIC CANCER (GC). THE INITIATION AND PROGRESSION OF GC ARE ASSOCIATED WITH INAPPROPRIATE IMMUNE RESPONSES CAUSED BY CHRONIC INFLAMMATION OF THE GASTRIC MUCOSA. TO IDENTIFY IMMUNOREGULATORY MOLECULES INVOLVED IN GC PROGRESSION, GC CELL LINES AND 200 PAIRS OF TUMOR AND NORMAL TISSUES FROM PATIENTS WITH GC WERE ANALYZED FOR GENE EXPRESSION, AMPLIFICATION AND METHYLATION AS WELL AS FUNCTION OF A DIFFERENTIALLY EXPRESSED GENE. THE TRANSCRIPTOME ANALYSIS REVEALED THAT MARGINAL ZONE B AND B1 CELL SPECIFIC PROTEIN (MZB1) WAS EXPRESSED AT SIGNIFICANTLY DECREASED LEVELS IN PRIMARY GC TISSUES WHEN COMPARED WITH THE CORRESPONDING NORMAL GASTRIC MUCOSA. PCR ARRAY ANALYSIS EXPLORING GENES EXPRESSED COOPERATIVELY WITH MZB1 REVEALED THAT DIFFERENTIAL EXPRESSION OF MZB1 MRNA IN GC CELL LINES CORRELATED POSITIVELY WITH THE LEVELS OF THE MRNAS ENCODING ESTROGEN RECEPTOR 1 AND DESUMOYLATING ISOPEPTIDASE 1. HYPERMETHYLATION OF THE MZB1 PROMOTER WAS FREQUENT IN CELL LINES WITH DECREASED LEVELS OF MZB1 MRNA. SIRNA-MEDIATED KNOCKDOWN OF MZB1 SIGNIFICANTLY INCREASED PROLIFERATION, INVASION AND MIGRATION OF GC CELL LINES. LOW MZB1 EXPRESSION WAS AN INDEPENDENT PROGNOSTIC FACTOR FOR RECURRENCE AFTER CURATIVE GASTRECTOMY AND WAS ASSOCIATED SIGNIFICANTLY WITH INCREASED HEMATOGENOUS RECURRENCE. MZB1 ACTS AS A SUPPRESSOR OF GC. LOW MZB1 EXPRESSION IN THE PRIMARY GC TISSUE IS PREDICTIVE OF RECURRENCE AFTER CURATIVE RESECTION.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
17 1629  24 DNMT3A ARG882 MUTATION DRIVES CHRONIC MYELOMONOCYTIC LEUKEMIA THROUGH DISTURBING GENE EXPRESSION/DNA METHYLATION IN HEMATOPOIETIC CELLS. THE GENE ENCODING DNA METHYLTRANSFERASE 3A (DNMT3A) IS MUTATED IN APPROXIMATELY 20% OF ACUTE MYELOID LEUKEMIA CASES, WITH ARG882 (R882) AS THE HOTSPOT. HERE, WE ADDRESSED THE TRANSFORMATION ABILITY OF THE DNMT3A-ARG882HIS (R882H) MUTANT BY USING A RETROVIRAL TRANSDUCTION AND BONE MARROW TRANSPLANTATION (BMT) APPROACH AND FOUND THAT THE MUTANT GENE CAN INDUCE ABERRANT PROLIFERATION OF HEMATOPOIETIC STEM/PROGENITOR CELLS. AT 12 MO POST-BMT, ALL MICE DEVELOPED CHRONIC MYELOMONOCYTIC LEUKEMIA WITH THROMBOCYTOSIS. RNA MICROARRAY ANALYSIS REVEALED ABNORMAL EXPRESSIONS OF SOME HEMATOPOIESIS-RELATED GENES, AND THE DNA METHYLATION ASSAY IDENTIFIED CORRESPONDING CHANGES IN METHYLATION PATTERNS IN GENE BODY REGIONS. MOREOVER, DNMT3A-R882H INCREASED THE CDK1 PROTEIN LEVEL AND ENHANCED CELL-CYCLE ACTIVITY, THEREBY CONTRIBUTING TO LEUKEMOGENESIS.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
18 2126  55 EPIGENETIC INACTIVATION OF MIR-34B/C IN ADDITION TO MIR-34A AND DAPK1 IN CHRONIC LYMPHOCYTIC LEUKEMIA. BACKGROUND: TP53 MUTATION/DELETION IS UNCOMMON IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). WE POSTULATED THAT COMPONENTS OF TP53-CENTERED TUMOR SUPPRESSOR NETWORK, MIR-34B/C, IN ADDITION TO DAPK1 AND MIR-34A MIGHT BE INACTIVATED BY DNA HYPERMETHYLATION. MOREOVER, WE TESTED IF MIR-34B/C METHYLATION MIGHT CORRELATE WITH MIR-203 OR MIR-124-1 METHYLATION IN CLL. METHODS: MIR-34B/C, MIR-34A AND DAPK1 METHYLATION WAS STUDIED IN 11 NORMAL CONTROLS, 7 CLL CELL LINES, AND 78 DIAGNOSTIC CLL SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. MEC-1 CELLS WERE TREATED WITH 5-AZA-2'-DEOXYCYTIDINE FOR REVERSAL OF METHYLATION-ASSOCIATED MIRNA SILENCING. TUMOR SUPPRESSOR PROPERTIES OF MIR-34B WERE DEMONSTRATED BY OVER-EXPRESSION OF PRECURSOR MIR-34B IN MEC-1 CELLS. RESULTS: MIR-34B/C PROMOTER WAS UNMETHYLATED IN NORMAL CONTROLS, BUT COMPLETELY METHYLATED IN 4 CLL CELL LINES. MIR-34B/C EXPRESSION WAS INVERSELY CORRELATED WITH MIR-34B/C METHYLATION. DIFFERENT MSP STATUSES OF MIR-34B/C, INCLUDING COMPLETE METHYLATION AND COMPLETE UNMETHYLATION, WERE VERIFIED BY QUANTITATIVE BISULFITE PYROSEQUENCING. 5-AZA-2'-DEOXYCYTIDINE TREATMENT RESULTED IN PROMOTER DEMETHYLATION AND MIR-34B RE-EXPRESSION IN MEC1 CELLS. MOREOVER, OVER-EXPRESSION OF MIR-34B RESULTED IN INHIBITION OF CELLULAR PROLIFERATION AND INCREASED CELL DEATH. IN PRIMARY CLL SAMPLES, MIR-34A, MIR-34B/C AND DAPK1 METHYLATION WAS DETECTED IN 2.6%, 17.9% AND 34.6% OF PATIENTS AT DIAGNOSIS RESPECTIVELY. FURTHERMORE, 39.7%, 3.8% AND 2.6% PATIENTS HAD METHYLATION OF ONE, TWO OR ALL THREE GENES RESPECTIVELY. OVERALL, 46.2% PATIENTS HAD METHYLATION OF AT LEAST ONE OF THESE THREE GENES. BESIDES, MIR-34B/C METHYLATION WAS ASSOCIATED WITH METHYLATION OF MIR-34A (P = 0.03) AND MIR-203 (P = 0.012) IN CLL. CONCLUSIONS: TAKEN TOGETHER, MIR-34B/C IS A TUMOR SUPPRESSOR MIRNA FREQUENTLY METHYLATED, AND HENCE SILENCED IN CLL. TOGETHER WITH DAPK1 METHYLATION, MIR-34B/C METHYLATION IS IMPLICATED IN THE DISRUPTION OF THE TP53-CENTERED TUMOR SUPPRESSOR NETWORK. MOREOVER, THE ASSOCIATION OF MIRNA METHYLATION WARRANTS FURTHER STUDY.	2014	
                          
19 2088  34 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	

20 5101  26 POLYCOMB FACTOR PHF19 CONTROLS CELL GROWTH AND DIFFERENTIATION TOWARD ERYTHROID PATHWAY IN CHRONIC MYELOID LEUKEMIA CELLS. POLYCOMB GROUP (PCG) OF PROTEINS ARE A GROUP OF HIGHLY CONSERVED EPIGENETIC REGULATORS INVOLVED IN MANY BIOLOGICAL FUNCTIONS, SUCH AS EMBRYONIC DEVELOPMENT, CELL PROLIFERATION, AND ADULT STEM CELL DETERMINATION. PHD FINGER PROTEIN 19 (PHF19) IS AN ASSOCIATED FACTOR OF POLYCOMB REPRESSOR COMPLEX 2 (PRC2), OFTEN UPREGULATED IN HUMAN CANCERS. IN PARTICULAR, MYELOID LEUKEMIA CELL LINES SHOW INCREASED LEVELS OF PHF19, YET LITTLE IS KNOWN ABOUT ITS FUNCTION. HERE, WE HAVE CHARACTERIZED THE ROLE OF PHF19 IN MYELOID LEUKEMIA CELLS. WE DEMONSTRATED THAT PHF19 DEPLETION DECREASES CELL PROLIFERATION AND PROMOTES CHRONIC MYELOID LEUKEMIA (CML) DIFFERENTIATION. MECHANISTICALLY, WE HAVE SHOWN HOW PHF19 REGULATES THE PROLIFERATION OF CML THROUGH A DIRECT REGULATION OF THE CELL CYCLE INHIBITOR P21. FURTHERMORE, WE OBSERVED THAT MTF2, A PHF19 HOMOLOG, PARTIALLY COMPENSATES FOR PHF19 DEPLETION IN A SUBSET OF TARGET GENES, INSTRUCTING SPECIFIC ERYTHROID DIFFERENTIATION. TAKEN TOGETHER, OUR RESULTS SHOW THAT PHF19 IS A KEY TRANSCRIPTIONAL REGULATOR FOR CELL FATE DETERMINATION AND COULD BE A POTENTIAL THERAPEUTIC TARGET FOR MYELOID LEUKEMIA TREATMENT.	2021