1 2355 97 EPIGENETIC REGULATION OF PRAME GENE IN CHRONIC MYELOID LEUKEMIA. TUMOR ASSOCIATED ANTIGENS (TAA) PROVIDE ATTRACTIVE TARGETS FOR CANCER-SPECIFIC IMMUNOTHERAPY. PRAME IS A TAA GENE UP-REGULATED IN ADVANCED PHASES OF CHRONIC MYELOID LEUKEMIA (CML). TO DATE, MOLECULAR MECHANISMS FOR THE EXPRESSION OF PRAME HAVE NEVER BEEN STUDIED. WE FOUND THAT SOME PH'-POSITIVE CELL LINES DID NOT EXPRESS PRAME. THE EXPRESSION OF PRAME WAS RESTORED IN THESE CELL LINES BY TREATMENT WITH 5'-AZA-2'-DEOXYCYTIDINE, SUGGESTING THAT THE EXPRESSION OF PRAME IS MAINLY SUPPRESSED BY HYPERMETHYLATION. BISULFITE SEQUENCING ANALYSIS OF THE CPG SITES OF THE PRAME EXON 2 IN THESE CANCER CELL LINES REVEALED A CLOSE RELATIONSHIP BETWEEN THE METHYLATION STATUS OF THE PRAME GENE AND ITS EXPRESSION. A METHYLATION-SPECIFIC PCR ANALYSIS DEMONSTRATED THAT HYPOMETHYLATION OF PRAME WAS SIGNIFICANTLY MORE FREQUENT IN CML BLAST CRISIS (70%) THAN IN CHRONIC PHASE (36%) (P=0.01) AND WAS CORRELATED WITH HIGH EXPRESSION LEVELS OF PRAME TRANSCRIPTS (P<0.0001). THESE RESULTS SUGGEST THAT HYPOMETHYLATION OF PRAME UP-REGULATES ITS EXPRESSION IN CML AND MIGHT PLAY A SIGNIFICANT ROLE IN THE PROGRESSION OF THE DISEASE.	2007	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
2  150 49 ABERRANT HYPOMETHYLATION OF THE CANCER-TESTIS ANTIGEN PRAME CORRELATES WITH PRAME EXPRESSION IN ACUTE MYELOID LEUKEMIA. PRAME IS A TUMOR-ASSOCIATED ANTIGEN, WHICH BELONGS TO THE FAMILY OF CANCER-TESTIS ANTIGENS (CTA). THE EXPRESSION OF CTA IS MAINLY RESTRICTED TO THE TESTIS AND VARIOUS TUMORS. IN CONTRAST TO OTHER CTA, PRAME EXPRESSION IS ALSO FREQUENTLY DETECTED IN ACUTE AND CHRONIC LEUKEMIAS. DUE TO THIS EXPRESSION PATTERN, PRAME HAS ATTRACTED GREAT INTEREST AS A PROGNOSTIC TUMOR MARKER THAT CAN BE USED FOR THE DETECTION OF MINIMAL RESIDUAL DISEASE AND AS A POTENTIAL TARGET FOR IMMUNOTHERAPY. IN ACUTE MYELOID LEUKEMIA (AML), PRAME EXPRESSION HAS BEEN OBSERVED IN 30-64% OF CASES. TO EVALUATE WHETHER EPIGENETIC MECHANISMS CONTRIBUTE TO PRAME ACTIVATION IN AML, WE STUDIED DNA METHYLATION OF 15 CPG DINUCLEOTIDES WITHIN A CPG-RICH REGION LOCATED IN THE INTRON 1 OF THE PRAME GENE. DNA METHYLATION WAS DETERMINED BY SEQUENCE ANALYSIS OF CLONED PCR PRODUCTS GENERATED FROM BISULFITE-TREATED GENOMIC DNA. METHYLATION PATTERNS WERE CORRELATED WITH PRAME MRNA LEVELS AS DETERMINED BY MICROARRAY ANALYSIS AND REAL-TIME PCR. WE FOUND ALMOST COMPLETE METHYLATION IN MONONUCLEAR BLOOD CELLS FROM TWO HEALTHY DONORS AND IN BONE MARROW CELLS OF FOUR PRAME-NEGATIVE AML PATIENTS. IN CONTRAST, THE DEGREE OF PRAME METHYLATION WAS CLEARLY REDUCED IN FOUR PRAME-POSITIVE AML BONE MARROW SAMPLES. IN PARTICULAR, THESE SAMPLES WERE CHARACTERIZED BY THE PRESENCE OF CLONES, WHICH WERE COMPLETELY DEVOID OF METHYLATION. THE SIGNIFICANT INVERSE CORRELATION BETWEEN THE DEGREE OF METHYLATION AND PRAME EXPRESSION SUGGESTS A CAUSAL ROLE OF DNA METHYLATION IN PRAME REGULATION. SUCH A ROLE IS FURTHER SUPPORTED BY THE OBSERVATION THAT TREATMENT OF PRAME-NEGATIVE CELL LINES U-937 AND THP-1 WITH THE DEMETHYLATING AGENT 5'-AZA-2'DC RESULTED IN A DOSE-RELATED UPREGULATION OF PRAME EXPRESSION.	2008	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
3 2765 40 EXPRESSION, EPIGENETIC REGULATION, AND HUMORAL IMMUNOGENICITY OF CANCER-TESTIS ANTIGENS IN CHRONIC MYELOID LEUKEMIA. OBJECTIVE: CANCER-TESTIS (CT) ANTIGENS REPRESENT ATTRACTIVE TARGETS FOR TUMOR IMMUNOTHERAPY BASED ON THEIR TUMOR-RESTRICTED EXPRESSION AND IMMUNOGENICITY. HOWEVER, A BROAD PICTURE OF THE EXPRESSION OF CT ANTIGENS AND ASSOCIATED HUMORAL IMMUNE RESPONSES IN CHRONIC MYELOID LEUKEMIA (CML) IS STILL MISSING. METHODS: WE SCREENED CML CELL LINES AND BONE MARROW (BM) SAMPLES FROM HEALTHY DONORS BY RT-PCR FOR THE EXPRESSION OF 31 CT ANTIGENS BEFORE AND AFTER TREATMENT WITH EPIGENETIC AGENTS. EXPRESSION OF TUMOR-RESTRICTED ANTIGENS WAS FURTHER EXAMINED IN 60 CML PATIENTS AND HUMORAL IMMUNE RESPONSES AGAINST 15 CT ANTIGENS WERE SCREENED BY ELISA. RESULTS: IN UNTREATED CELL LINES WE DETECTED THE EXPRESSION OF 17 CT ANTIGENS THAT WERE ABSENT FROM NORMAL BM. EXPRESSION OF MOST ANTIGENS INCREASED FOLLOWING DEMETHYLATING TREATMENT WITH 5'-AZA-2'-DEOXYCYTIDINE. IN THESE SAMPLES, ONLY PRAME WAS REPEATEDLY DETECTED AND EXPRESSION CORRELATED WITH SEVERAL CLINICOPATHOLOGICAL PARAMETERS AND DECREASED OVERALL SURVIVAL. WE FURTHER SHOW THAT A LOWER FREQUENCY OF PRAME-POSITIVE SAMPLES DURING IMATINIB TREATMENT WAS NOT CAUSED BY GENE-SPECIFIC DOWNREGULATION. ANALYZING THE PATIENTS' ANTIBODY RESPONSES WE FOUND THAT THE VAST MAJORITY OF PATIENTS LACKED SPONTANEOUS IMMUNITY AGAINST CT ANTIGENS INCLUDING PRAME. CONCLUSIONS: CT ANTIGEN EXPRESSION CAN BE INCREASED BY THE APPLICATION OF EPIGENETIC AGENTS AND THE EXPRESSION OF PRAME CORRELATES WITH CLINICOPATHOLOGICAL PARAMETERS AND OVERALL SURVIVAL IN PATIENTS WITH CML, BUT DOES NOT LEAD TO HUMORAL IMMUNE RESPONSES. PRAME-SPECIFIC IMMUNOTHERAPY MIGHT REPRESENT A PROMISING APPROACH FOR THE ERADICATION OF RESIDUAL THERAPY-RESISTANT LEUKEMIC CELLS DUE TO ITS FREQUENT EXPRESSION AND STABILITY UNDER IMATINIB TREATMENT.	2010	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
4  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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
5 3532 41 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                  
6  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	

7   59 41 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
8 5669 27 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 3444 31 HYPERMETHYLATION OF E-CADHERIN IN LEUKEMIA. E-CADHERIN GENE IS OFTEN TERMED A "METASTASIS SUPPRESSOR" GENE BECAUSE THE E-CADHERIN PROTEIN CAN SUPPRESS TUMOR CELL INVASION AND METASTASIS. INACTIVATION OF THE E-CADHERIN GENE OCCURS IN UNDIFFERENTIATED SOLID TUMORS BY BOTH GENETIC AND EPIGENETIC MECHANISMS; HOWEVER, THE ROLE OF E-CADHERIN IN HEMATOLOGIC MALIGNANCIES IS ONLY NOW BEING RECOGNIZED. E-CADHERIN EXPRESSION IS ESSENTIAL FOR ERYTHROBLAST AND NORMOBLAST MATURATION, YET EXPRESSION IS REDUCED OR ABSENT IN LEUKEMIC BLAST CELLS. THIS STUDY EXAMINED THE MESSENGER RNA (MRNA) AND PROTEIN EXPRESSION OF THE E-CADHERIN GENE IN BONE MARROW AND BLOOD SAMPLES FROM NORMAL DONORS AND PATIENTS WITH LEUKEMIA. WE FOUND THAT ALL NORMAL DONOR SAMPLES EXPRESSED E-CADHERIN MRNA, WHEREAS BOTH SAMPLES OF ACUTE MYELOGENOUS LEUKEMIA AND CHRONIC LYMPHOCYTIC LEUKEMIA HAD A SIGNIFICANT REDUCTION OR ABSENCE OF EXPRESSION. HOWEVER, NORMAL BLAST COUNTERPARTS EXPRESSED ONLY A LOW LEVEL OF E-CADHERIN SURFACE PROTEIN. SODIUM BISULPHITE GENOMIC SEQUENCING WAS USED TO FULLY CHARACTERIZE THE METHYLATION PATTERNS OF THE CPG ISLAND ASSOCIATED WITH THE E-CADHERIN GENE PROMOTER IN THOSE SAMPLES WITH MATCHED DNA. ALL OF THE NORMAL CONTROL SAMPLES WERE ESSENTIALLY UNMETHYLATED; HOWEVER, 14 OF 18 (78%) OF THE LEUKEMIA SAMPLES HAD ABNORMAL HYPERMETHYLATION OF THE E-CADHERIN CPG ISLAND. IN FACT BOTH ALLELES OF THE E-CADHERIN GENE WERE OFTEN HYPERMETHYLATED. WE CONCLUDE THE E-CADHERIN GENE IS A COMMON TARGET FOR HYPERMETHYLATION IN HEMATOLOGIC MALIGNANCIES.	2000	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
10 4243 38 METHYLATION STATUS OF CEBPA GENE PROMOTER IN CHRONIC MYELOID LEUKEMIA. CCAAT/ENHANCER BINDING PROTEIN ALPHA IS ONE OF THE CRUCIAL TRANSCRIPTION FACTORS FOR MYELOID CELL DEVELOPMENT THAT HAS BEEN FOUND TO BE INVOLVED IN HEMATOPOIETIC DIFFERENTIATION AND LEUKEMIOGENESIS. RECENTLY, EPIGENETIC REGULATION OF CEBPA EXPRESSION THROUGH DNA METHYLATION HAS BEEN DEMONSTRATED IN LEUKEMIA. THE AIM OF THIS STUDY WAS TO INVESTIGATE THE METHYLATION STATUS OF CEBPA GENE IN CHRONIC MYELOID LEUKEMIA (CML) PATIENTS. THE METHYLATION STATUS OF CEBPA PROMOTER WAS STUDIED IN 100 PATIENTS WITH CML AND 98 NORMAL HEALTHY INDIVIDUALS FROM HYDERABAD, INDIA, USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. THE ABERRANT METHYLATION OF CEBPA GENE PROMOTER WAS FOUND IN 32 OF THE 100 CML CASES. A HIGHLY SIGNIFICANT ASSOCIATION WAS FOUND BETWEEN THE FREQUENCY OF CEBPA GENE PROMOTER HYPERMETHYLATION AND THE CML STAGES (P = 0.017), BUT ASSOCIATION WITH RESPECT TO AGE AND GENDER OF THE PATIENT WAS NOT FOUND. THE RESULTS SUGGEST THAT ABERRANT METHYLATION IN THE CPG ISLAND OF THE PROMOTER REGION OF THIS GENE MIGHT BE A COMMON EVENT IN CML, AND SYSTEMIC EXPRESSION STUDIES WILL BE NEEDED TO UNFOLD THE ROLE OF CEBPA PROMOTER METHYLATION IN THE DEVELOPMENT, PROGRESSION, AND PROGNOSIS OF CML.	2014	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
11 4694 40 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
12 3461 39 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
13 1669 35 DOWNREGULATION OF THE HISTONE METHYLTRANSFERASE SETD2 PROMOTES IMATINIB RESISTANCE IN CHRONIC MYELOID LEUKAEMIA CELLS. OBJECTIVES: EPIGENETIC MODIFIERS WERE IMPORTANT PLAYERS IN THE DEVELOPMENT OF HAEMATOLOGICAL MALIGNANCIES AND SENSITIVITY TO THERAPY. MUTATIONS OF SET DOMAIN-CONTAINING 2 (SETD2), A METHYLTRANSFERASE THAT CATALYSES THE TRIMETHYLATION OF HISTONE 3 ON LYSINE 36 (H3K36ME3), WERE FOUND IN VARIOUS MYELOID MALIGNANCIES. HOWEVER, THE DETAILED MECHANISMS THROUGH WHICH SETD2 CONFERS CHRONIC MYELOID LEUKAEMIA PROGRESSION AND RESISTANCE TO THERAPY TARGETING ON BCR-ABL REMAIN UNCLEAR. MATERIALS AND METHODS: THE LEVEL OF SETD2 IN IMATINIB-SENSITIVE AND IMATINIB-RESISTANT CHRONIC MYELOID LEUKAEMIA (CML) CELLS WAS EXAMINED BY IMMUNOBLOTTING AND QUANTITATIVE REAL-TIME PCR. WE ANALYSED CD34(+) CD38(-) LEUKAEMIC STEM CELLS BY FLOW CYTOMETRY AND COLONY FORMATION ASSAYS UPON SETD2 KNOCKDOWN OR OVEREXPRESSION. THE IMPACT OF SETD2 EXPRESSION ALTERATIONS OR SMALL-MOLECULE INHIBITOR JIB-04 TARGETING H3K36ME3 LOSS ON IMATINIB SENSITIVITY WAS ASSESSED BY IC50, CELL APOPTOSIS AND PROLIFERATION ASSAYS. FINALLY, RNA SEQUENCING AND CHIP-QUANTITATIVE PCR WERE PERFORMED TO VERIFY PUTATIVE DOWNSTREAM TARGETS. RESULTS: SETD2 WAS FOUND TO ACT AS A TUMOUR SUPPRESSOR IN CML. THE NOVEL ONCOGENIC TARGETS MYCN AND ERG WERE SHOWN TO BE THE DIRECT DOWNSTREAM TARGETS OF SETD2, WHERE THEIR OVEREXPRESSION INDUCED BY SETD2 KNOCKDOWN CAUSED IMATINIB INSENSITIVITY AND LEUKAEMIC STEM CELL ENRICHMENT IN CML CELL LINES. TREATMENT WITH JIB-04, AN INHIBITOR THAT RESTORES H3K36ME3 LEVELS THROUGH BLOCKADE OF ITS DEMETHYLATION, SUCCESSFULLY IMPROVED THE CELL IMATINIB SENSITIVITY AND ENHANCED THE CHEMOTHERAPEUTIC EFFECT. CONCLUSIONS: OUR STUDY NOT ONLY EMPHASIZES THE REGULATORY MECHANISM OF SETD2 IN CML, BUT ALSO PROVIDES PROMISING THERAPEUTIC STRATEGIES FOR OVERCOMING THE IMATINIB RESISTANCE IN PATIENTS WITH CML.	2019	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
14 2327 59 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
15  151 30 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
16 3087 32 GENOME?WIDE EXPRESSION AND METHYLATION ANALYSES REVEAL ABERRANT CELL ADHESION SIGNALING IN TYROSINE KINASE INHIBITOR?RESISTANT CML CELLS. ALTHOUGH CHRONIC MYELOID LEUKEMIA (CML) CAN BE EFFECTIVELY TREATED USING BCR?ABL1 KINASE INHIBITORS, RESISTANCE DUE TO KINASE ALTERATIONS OR TO BCR?ABL1 INDEPENDENT MECHANISMS REMAIN A THERAPEUTIC CHALLENGE. FOR THE LATTER, THE UNDERLYING MECHANISMS ARE WIDELY DISCUSSED; FOR INSTANCE, GENE EXPRESSION CHANGES, EPIGENETIC FACTORS AND ALTERNATIVE SIGNALING PATHWAY ACTIVATION. IN THE PRESENT STUDY, IN VITRO?CML CELL MODELS OF RESISTANCE AGAINST THE TYROSINE KINASE INHIBITORS (TKIS) IMATINIB (0.5 AND 2 MICROM) AND NILOTINIB (0.1 MICROM) WITH BIOLOGICAL REPLICATES WERE GENERATED TO IDENTIFY NOVEL MECHANISMS OF RESISTANCE. SUBSEQUENTLY, GENOME?WIDE MRNA EXPRESSION AND DNA METHYLATION WERE ANALYZED. WHILE MRNA EXPRESSION PATTERNS DIFFERED LARGELY BETWEEN BIOLOGICAL REPLICATES, THERE WAS AN OVERLAP OF 71 GENES DIFFERENTIALLY EXPRESSED BETWEEN CELLS RESISTANT AGAINST IMATINIB OR NILOTINIB. MOREOVER, ALL TKI RESISTANT CELL LINES DEMONSTRATED A SLIGHT HYPERMETHYLATION COMPARED WITH NATIVE CELLS. IN A COMBINED ANALYSIS OF 151 GENES DIFFERENTIALLY EXPRESSED IN THE BIOLOGICAL REPLICATES OF IMATINIB RESISTANCE, CELL ADHESION SIGNALING, IN PARTICULAR THE CELLULAR MATRIX PROTEIN FIBRONECTIN 1 (FN1), WAS SIGNIFICANTLY DYSREGULATED. THIS GENE WAS ALSO DOWNREGULATED IN NILOTINIB RESISTANCE. FURTHER ANALYSES SHOWED SIGNIFICANT FN1?DOWNREGULATION IN IMATINIB RESISTANCE ON MRNA (P<0.001) AND PROTEIN LEVEL (P<0.001). SIRNA?MEDIATED FN1?KNOCKDOWN IN NATIVE CELLS REDUCED CELL ADHESION (P=0.02), DECREASED IMATINIB SUSCEPTIBILITY VISIBLE BY HIGHER KI?67 EXPRESSION (1.5?FOLD, P=0.04) AND INCREASED CELL NUMBER (1.5?FOLD, P=0.03). VICE VERSA, RECOVERY OF FN1?EXPRESSION IN IMATINIB RESISTANT CELLS WAS SUFFICIENT TO PARTIALLY RESTORE THE RESPONSE TO IMATINIB. OVERALL, THESE RESULTS SUGGESTED A ROLE OF CELL ADHESION SIGNALING AND FIBRONECTIN 1 IN TKI RESISTANT CML AND A POTENTIAL TARGET FOR NOVEL STRATEGIES IN TREATMENT OF RESISTANT CML.	2022	
                                                                                                                                                                                                                                                                                                                                                                 
17 1968 35 EPIGENETIC ALTERATION OF THE SOCS1 GENE IN CHRONIC MYELOID LEUKAEMIA. THE EXPRESSION OF THE SUPPRESSOR OF CYTOKINE SIGNALLING-1 (SOCS1) PROTEIN IS INDUCED IN RESPONSE TO STIMULATION BY SEVERAL CYTOKINES. THE INDUCED SOCS1 INHIBITS THE SIGNALLING PATHWAY THROUGH THE ASSOCIATION WITH A VARIETY OF TYROSINE KINASE PROTEINS. IN THIS STUDY, THE MUTATION ANALYSES, CPG ISLAND METHYLATION STATUS, AND THE EXPRESSION OF THE SOCS1 GENE IN 112 CHRONIC MYELOID LEUKAEMIA (CML) SAMPLES, FIVE LEUKAEMIA CELL LINES, AND 30 NORMAL CONTROLS WERE ANALYSED. NO GENETIC MUTATIONS OF SOCS1 GENE WERE NOTED IN THE CML SAMPLES. THE SOCS1 GENE WAS HYPERMETHYLATED IN 67% AND 46% OF THE BLASTIC AND CHRONIC PHASE CML SAMPLES RESPECTIVELY (P < 0.0001). HOWEVER, THERE WAS NO METHYLATION OF THE SOCS1 GENE IN NORMAL CONTROLS OR CML IN MOLECULAR REMISSION. THE METHYLATION STATUS OF THE SOCS1 GENE IS CONSISTENT WITH THE RESULTS OF THE REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION AND IMMUNOCYTOCHEMISTRY STAINING. OUR RESULTS DEMONSTRATE THAT THE SOCS1 GENE SILENCING IS CAUSED BY THE METHYLATION OF CPG ISLANDS IN CML AND IS REVERSED TO AN UNMETHYLATED STATUS IN MOLECULAR REMISSION. AS SOCS1 HAS UNIVERSAL ACTIVITY TO NEGATIVELY REGULATE SEVERAL CYTOKINE SIGNALLING PATHWAYS, THE LOSS OF THE NEGATIVE REGULATION OF CYTOKINE SIGNALLING BY THE SOCS1 MAY PLAY A ROLE IN THE PATHOGENESIS OF CML PROGRESSION.	2003	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
18 5259 31 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
19  825 29 CHARACTERIZATION OF FUNCTIONAL TRANSPOSABLE ELEMENT ENHANCERS IN ACUTE MYELOID LEUKEMIA. TRANSPOSABLE ELEMENTS (TES) HAVE BEEN SHOWN TO HAVE IMPORTANT GENE REGULATORY FUNCTIONS AND THEIR ALTERATION COULD LEAD TO DISEASE PHENOTYPES. ACUTE MYELOID LEUKEMIA (AML) DEVELOPS AS A CONSEQUENCE OF A SERIES OF GENETIC CHANGES IN HEMATOPOIETIC PRECURSOR CELLS, INCLUDING MUTATIONS IN EPIGENETIC FACTORS. HERE, WE SET OUT TO STUDY THE GENE REGULATORY ROLE OF TES IN AML. WE FIRST EXPLORED THE EPIGENETIC LANDSCAPE OF TES IN AML PATIENTS USING ATAC-SEQ DATA. WE SHOW THAT A LARGE NUMBER OF TES IN GENERAL, AND MORE SPECIFICALLY MAMMALIAN-WIDE INTERSPERSED REPEATS (MIRS), ARE MORE ENRICHED IN AML CELLS THAN IN NORMAL BLOOD CELLS. WE OBTAINED A SIMILAR FINDING WHEN ANALYZING HISTONE MODIFICATION DATA IN AML PATIENTS. GENE ONTOLOGY ENRICHMENT ANALYSIS SHOWED THAT GENES NEAR MIRS IN OPEN CHROMATIN REGIONS ARE INVOLVED IN LEUKEMOGENESIS. TO FUNCTIONALLY VALIDATE THEIR REGULATORY ROLE, WE SELECTED 19 MIR REGIONS IN AML CELLS, AND TESTED THEM FOR ENHANCER ACTIVITY IN AN AML CELL LINE (KASUMI-1) AND A CHRONIC MYELOID LEUKEMIA (CML) CELL LINE (K562); THE RESULTS REVEALED SEVERAL MIRS TO BE FUNCTIONAL ENHANCERS. TAKEN TOGETHER, OUR RESULTS SUGGEST THAT TES ARE POTENTIALLY INVOLVED IN MYELOID LEUKEMOGENESIS AND HIGHLIGHT THESE SEQUENCES AS POTENTIAL CANDIDATES HARBORING AML-ASSOCIATED VARIATION.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
20 1662 21 DOWNREGULATION OF DEATH-ASSOCIATED PROTEIN KINASE 1 (DAPK1) IN CHRONIC LYMPHOCYTIC LEUKEMIA. THE HERITABILITY OF B CELL CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS RELATIVELY HIGH; HOWEVER, NO PREDISPOSING MUTATION HAS BEEN CONVINCINGLY IDENTIFIED. WE SHOW THAT LOSS OR REDUCED EXPRESSION OF DEATH-ASSOCIATED PROTEIN KINASE 1 (DAPK1) UNDERLIES CASES OF HERITABLE PREDISPOSITION TO CLL AND THE MAJORITY OF SPORADIC CLL. EPIGENETIC SILENCING OF DAPK1 BY PROMOTER METHYLATION OCCURS IN ALMOST ALL SPORADIC CLL CASES. FURTHERMORE, WE DEFINED A DISEASE HAPLOTYPE, WHICH SEGREGATES WITH THE CLL PHENOTYPE IN A LARGE FAMILY. DAPK1 EXPRESSION OF THE CLL ALLELE IS DOWNREGULATED BY 75% IN GERMLINE CELLS DUE TO INCREASED HOXB7 BINDING. IN THE BLOOD CELLS FROM AFFECTED FAMILY MEMBERS, PROMOTER METHYLATION RESULTS IN ADDITIONAL LOSS OF DAPK1 EXPRESSION. THUS, REDUCED EXPRESSION OF DAPK1 CAN RESULT FROM GERMLINE PREDISPOSITION, AS WELL AS EPIGENETIC OR SOMATIC EVENTS CAUSING OR CONTRIBUTING TO THE CLL PHENOTYPE.	2007