1 2440 114 EPIGENETIC SILENCING OF TUMOR SUPPRESSOR LONG NON-CODING RNA BM742401 IN CHRONIC LYMPHOCYTIC LEUKEMIA. BM742401 IS A TUMOR SUPPRESSOR LNCRNA DOWNREGULATED IN GASTRIC CANCER. AS THE PROMOTER REGION AND THE ENTIRE TRANSCRIPT ARE EMBEDDED IN A CPG ISLAND, WE POSTULATED THAT BM742401 IS A TUMOR SUPPRESSOR LNCRNA INACTIVATED BY DNA METHYLATION IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). THE PROMOTER OF BM742401 WAS UNMETHYLATED IN NORMAL CONTROLS INCLUDING THREE EACH OF NORMAL BONE MARROW, PERIPHERAL BLOOD BUFFY COATS, AND CD19-SORTED PERIPHERAL B-CELLS, BUT METHYLATED IN FOUR (57.1%) CLL CELL LINES. METHYLATION OF BM742401 CORRELATED INVERSELY WITH EXPRESSION. IN THE COMPLETELY METHYLATED WAC3CD5+ CLL CELLS, 5-AZA-2'-DEOXYCYTIDINE TREATMENT LED TO PROMOTER DEMETHYLATION AND RE-EXPRESSION OF BM742401 TRANSCRIPT. FUNCTIONALLY, STABLE OVEREXPRESSION OF BM742401 RESULTED IN INHIBITION OF CELLULAR PROLIFERATION AND ENHANCED APOPTOSIS THROUGH CASPASE-9-DEPENDENT INTRINSIC BUT NOT CASPASE-8-DEPENDENT EXTRINSIC APOPTOSIS PATHWAY, SUGGESTING A TUMOR SUPPRESSOR ROLE OF BM742401 IN CLL. IN PRIMARY CLL SAMPLES, METHYLATION OF BM742401 WAS DETECTED IN 43/98 (43.9%) OF PATIENTS. MOREOVER, AMONG CLL PATIENTS WITH STANDARD-RISK CYTOGENETIC ABERRATIONS, METHYLATION OF BM742401 CORRELATED WITH ADVANCED RAI STAGE (>/= STAGE 2)(P = 0.002). FURTHERMORE, BM742401 METHYLATION WAS ASSOCIATED WITH MIR-129-2 METHYLATION (P = 0.05). BM742401 IS A TUMOR SUPPRESSOR LNCRNA FREQUENTLY METHYLATED IN CLL. THE MECHANISM OF BM742401 AS A TUMOR SUPPRESSOR WARRANTS FURTHER STUDIES. 2016 2 2126 57 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 3 2133 39 EPIGENETIC INACTIVATION OF THE MIR-34A IN HEMATOLOGICAL MALIGNANCIES. MIR-34A IS A TRANSCRIPTIONAL TARGET OF P53 AND IMPLICATED IN CARCINOGENESIS. WE STUDIED THE ROLE OF MIR-34A METHYLATION IN A PANEL OF HEMATOLOGICAL MALIGNANCIES INCLUDING ACUTE LEUKEMIA [ACUTE MYELOID LEUKEMIA (AML) AND ACUTE LYMPHOBLASTIC LEUKEMIA (ALL)], CHRONIC LEUKEMIA [CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND CHRONIC MYELOID LEUKEMIA (CML)], MULTIPLE MYELOMA (MM) AND NON-HODGKIN'S LYMPHOMA (NHL). THE METHYLATION STATUS OF MIR-34A PROMOTER WAS STUDIED IN 12 CELL LINES AND 188 DIAGNOSTIC SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. MIR-34A PROMOTER WAS UNMETHYLATED IN NORMAL CONTROLS BUT METHYLATED IN 75% LYMPHOMA AND 37% MYELOMA CELL LINES. HYPOMETHYLATING TREATMENT LED TO RE-EXPRESSION OF PRI-MIR-34A TRANSCRIPT IN LYMPHOMA CELLS WITH HOMOZYGOUS MIR-34A METHYLATION. IN PRIMARY SAMPLES AT DIAGNOSIS, MIR-34A METHYLATION WAS DETECTED IN 4% CLL, 5.5% MM SAMPLES AND 18.8% OF NHL AT DIAGNOSIS BUT NONE OF ALL, AML AND CML (P = 0.011). IN MM PATIENTS WITH PAIRED SAMPLES, MIR-34A METHYLATION STATUS REMAINED UNCHANGED AT PROGRESSION. AMONGST LYMPHOID MALIGNANCIES, MIR-34A WAS PREFERENTIALLY METHYLATED IN NHL (P = 0.018), IN PARTICULAR NATURAL KILLER (NK)/T-CELL LYMPHOMA. IN CONCLUSION, AMONGST HEMATOLOGICAL MALIGNANCIES, MIR-34A METHYLATION IS PREFERENTIALLY HYPERMETHYLATED IN NHL, IN PARTICULAR NK/T-CELL LYMPHOMA, IN A TUMOR-SPECIFIC MANNER, THEREFORE THE ROLE OF MIR-34A IN LYMPHOMAGENESIS WARRANTS FURTHER STUDY. 2010 4 2131 52 EPIGENETIC INACTIVATION OF THE HSA-MIR-203 IN HAEMATOLOGICAL MALIGNANCIES. MIR-203 IS A TUMOUR SUPPRESSOR MICRORNA (MIRNA). WE STUDIED THE METHYLATION OF HSA-MIR-203 IN 150 SAMPLES INCLUDING ACUTE MYELOID LEUKAEMIA (AML), ACUTE LYMPHOBLASTIC LEUKAEMIA (ALL), CHRONIC MYELOID LEUKAEMIA (CML), CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) AND NON-HODGKIN'S LYMPHOMA (NHL) BY METHYLATION-SPECIFIC PCR, AND MIRNA EXPRESSION BY STEM-LOOP RT-QPCR. HSA-MIR-203 PROMOTER WAS UNMETHYLATED IN NORMAL CONTROLS BUT HOMOZYGOUSLY METHYLATED IN TWO AML AND FOUR LYMPHOMA CELL LINES, IN WHICH 5-AZA-2'-DEOXYCYTIDINE TREATMENT LED TO PROMOTER DEMETHYLATION AND MIR-203 RE-EXPRESSION. RESTORATION OF MIR-203 EXPRESSION IN LYMPHOMA CELLS INHIBITED CELLULAR PROLIFERATION AND INCREASED CELL DEATH, SUGGESTING AN INHERENT TUMOUR SUPPRESSOR ACTIVITY. IN PRIMARY SAMPLES, HSA-MIR-203 METHYLATION WAS ABSENT IN CML BUT DETECTED IN 5.0% ALL, 10.0% AML, 42.0% CLL AND 38.8% OF NHL (INCLUDING SIX [60.0%] NATURAL KILLER-CELL, NINE [40.9%] B-CELL AND FOUR [23.5%] T CELL NHL). MOREOVER, HSA-MIR-203 METHYLATION WAS ASSOCIATED WITH HYPERMETHYLATION OF HSA-MIR-34A, -124A AND -196B IN NHL BUT NOT CLL. IN CLL, HSA-MIR-203 METHYLATION WAS ASSOCIATED WITH A HIGHER PRESENTING HB LEVEL (P = 0.033). THE PROJECTED 10 YEAR OVERALL SURVIVAL OF THE CLL PATIENTS WAS 58.2%, WHICH WAS IMPACTED BY RAI STAGE AND HIGH-RISK KARYOTYPES BUT NOT HSA-MIR-203 METHYLATION. HSA-MIR-203 WAS MORE FREQUENTLY METHYLATED IN LYMPHOID THAN MYELOID MALIGNANCIES (P = 0.002). IN CONCLUSION, MIR-203, A TUMOUR SUPPRESSOR GENE, WAS HYPERMETHYLATED IN A TUMOUR-SPECIFIC MANNER WITH GENE SILENCING. HSA-MIR-203 WAS MORE FREQUENTLY HYPERMETHYLATED IN LYMPHOID THAN MYELOID MALIGNANCIES. IN NHL, HSA-MIR-203 METHYLATION WAS ASSOCIATED WITH CONCOMITANT METHYLATION OF OTHER TUMOUR SUPPRESSOR MIRNAS. THE FREQUENT HSA-MIR-203 METHYLATION IN LYMPHOID MALIGNANCIES SUGGESTED A PATHOGENETIC ROLE OF HSA-MIR-203 METHYLATION. 2011 5 2426 56 EPIGENETIC SILENCING OF LONG NON-CODING RNA BM742401 IN MULTIPLE MYELOMA: IMPACT ON PROGNOSIS AND MYELOMA DISSEMINATION. BACKGROUND: LONG NON-CODING RNA (LNCRNA) BM742401 IS A TUMOR SUPPRESSOR IN GASTRIC CANCER AND CHRONIC LYMPHOCYTIC LEUKEMIA. AS THE PROMOTER AND CODING REGION OF BM742401 ARE FULLY EMBEDDED IN A CPG ISLAND, WE HYPOTHESIZED THAT BM742401 IS A TUMOR SUPPRESSOR LNCRNA EPIGENETICALLY SILENCED BY PROMOTER DNA METHYLATION IN MULTIPLE MYELOMA. METHODS: METHYLATION-SPECIFIC PCR AND QUANTITATIVE BISULFITE PYROSEQUENCING WERE PERFORMED TO DETECT THE METHYLATION OF BM742401 IN NORMAL PLASMA CELLS, MYELOMA CELL LINES AND PRIMARY MYELOMA SAMPLES. THE EXPRESSION OF BM742401 WAS MEASURED BY QRT-PCR. THE FUNCTION OF BM742401 IN MULTIPLE MYELOMA CELLS WAS ANALYZED BY LENTIVIRUS TRANSDUCTION FOLLOWED BY MIGRATION ASSAY. RESULTS: BM742401 METHYLATION WAS DETECTED IN 10 (66.7%) MYELOMA CELL LINES BUT NOT NORMAL PLASMA CELLS, AND INVERSELY CORRELATED WITH EXPRESSION OF BM742401. IN PRIMARY SAMPLES, BM742401 METHYLATION WAS DETECTED IN 3 (12.5%) MONOCLONAL GAMMOPATHY OF UNDETERMINED SIGNIFICANCE, 9 (15.8%) MYELOMA AT DIAGNOSIS AND 8 (17.0%) MYELOMA AT RELAPSE/PROGRESSION. MOREOVER, BM742401 METHYLATION AT DIAGNOSIS WAS ASSOCIATED WITH INFERIOR OVERALL SURVIVAL (MEDIAN OS: 25 VS. 39 MONTHS; P = 0.0496). IN MYELOMA CELL LINE JJN-3, STABLE OVEREXPRESSION OF BM742401 BY LENTIVIRUS TRANSDUCTION RESULTED IN REDUCED CELL MIGRATION (P = 0.0001) BUT NOT IMPACTING CELL DEATH OR PROLIFERATION. CONCLUSIONS: THIS IS THE FIRST REPORT OF TUMOR-SPECIFIC METHYLATION-MEDIATED SILENCING OF BM742401 IN MYELOMA, WHICH IS LIKELY AN EARLY EVENT IN MYELOMAGENESIS WITH ADVERSE IMPACT ON OVERALL SURVIVAL. MOREOVER, BM742401 IS A TUMOR SUPPRESSOR LNCRNA BY INHIBITING MYELOMA CELL MIGRATION, HENCE IMPLICATED IN MYELOMA PLASMA CELL HOMING, METASTASIS AND DISEASE PROGRESSION. 2020 6 2132 43 EPIGENETIC INACTIVATION OF THE MIR-124-1 IN HAEMATOLOGICAL MALIGNANCIES. MIR-124-1 IS A TUMOUR SUPPRESSOR MICRORNA (MIR). EPIGENETIC DEREGULATION OF MIRS IS IMPLICATED IN CARCINOGENESIS. PROMOTER DNA METHYLATION AND HISTONE MODIFICATION OF MIR-124-1 WAS STUDIED IN 5 NORMAL MARROW CONTROLS, 4 LYMPHOMA, 8 MULTIPLE MYELOMA (MM) CELL LINES, 230 DIAGNOSTIC PRIMARY SAMPLES OF ACUTE MYELOID LEUKAEMIA (AML), ACUTE LYMPHOBLASTIC LEUKAEMIA (ALL), CHRONIC MYELOID LEUKAEMIA (CML), CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL), MM, AND NON-HODGKIN'S LYMPHOMA (NHL), AND 53 MM SAMPLES AT STABLE DISEASE OR RELAPSE. PROMOTER OF MIR-124-1 WAS UNMETHYLATED IN NORMAL CONTROLS BUT HOMOZYGOUSLY METHYLATED IN 4 OF 4 LYMPHOMA AND 4 OF 8 MYELOMA CELL LINES. TREATMENT OF 5-AZA-2'-DEOXYCYTIDINE LED TO MIR-124-1 DEMETHYLATION AND RE-EXPRESSION OF MATURE MIR-124, WHICH ALSO ASSOCIATED WITH EMERGENCE OF EUCHROMATIC TRIMETHYL H3K4 AND CONSEQUENT DOWNREGULATION OF CDK6 IN MYELOMA CELLS HARBORING HOMOZYGOUS MIR-124-1 METHYLATION. IN PRIMARY SAMPLES AT DIAGNOSIS, MIR-124-1 METHYLATION WAS ABSENT IN CML BUT DETECTED IN 2% EACH OF MM AT DIAGNOSIS AND RELAPSE/PROGRESSION, 5% ALL, 15% AML, 14% CLL AND 58.1% OF NHL (P<0.001). AMONGST LYMPHOID MALIGNANCIES, MIR-124-1 WAS PREFERENTIALLY METHYLATED IN NHL THAN MM, CLL OR ALL. IN PRIMARY LYMPHOMA SAMPLES, MIR-124-1 WAS PREFERENTIALLY HYPERMETHYLATED IN B- OR NK/T-CELL LYMPHOMAS AND ASSOCIATED WITH REDUCED MIR-124 EXPRESSION. IN CONCLUSION, MIR-124-1 WAS HYPERMETHYLATED IN A TUMOUR-SPECIFIC MANNER, WITH A HETEROCHROMATIC HISTONE CONFIGURATION. HYPOMETHYLATION LED TO PARTIAL RESTORATION OF EUCHROMATIC HISTONE CODE AND MIR RE-EXPRESSION. INFREQUENT MIR-124-1 METHYLATION DETECTED IN DIAGNOSTIC AND RELAPSE MM SAMPLES SHOWED AN UNIMPORTANT ROLE IN MM PATHOGENESIS, DESPITE FREQUENT METHYLATION FOUND IN CELL LINES. AMONGST HAEMATOLOGICAL CANCERS, MIR-124-1 WAS MORE FREQUENTLY HYPERMETHYLATED IN NHL, AND HENCE WARRANTS FURTHER STUDY. 2011 7 4245 35 METHYLATION STATUS OF DDIT3 GENE IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: DNA-DAMAGE-INDUCIBLE TRANSCRIPT 3 (DDIT3), A CANDIDATE TUMOR SUPPRESSOR GENE (TSG), HAS BEEN FOUND INVOLVED IN THE REGULATION OF CELLULAR GROWTH AND DIFFERENTIATION. THE EPIGENETIC CHANGES OF TSGS ARE RECENTLY RECOGNIZED AS AN ABNORMAL MECHANISM CONTRIBUTING TO THE DEVELOPMENT OF CHRONIC MYELOID LEUKEMIA (CML). THE AIM OF THIS STUDY WAS TO INVESTIGATE THE METHYLATION STATUS OF DDIT3 GENE IN CML PATIENTS. METHODS: THE METHYLATION STATUS OF DDIT3 PROMOTER WAS DETECTED IN THE BONE MARROW MONONUCLEAR CELLS FROM 53 PATIENTS WITH CML USING METHYLATION-SPECIFIC PCR (MSP). THE EXPRESSION LEVELS OF DDIT3 AND BCR/ABL TRANSCRIPT WERE DETERMINED BY REAL-TIME QUANTITATIVE PCR (RQ-PCR). CLINICAL DATA OF THESE PATIENTS WERE COLLECTED AND ANALYZED. RESULTS: THE ABERRANT METHYLATION OF DDIT3 GENE PROMOTER WAS FOUND IN 35 OF 53 (66%) CML CASES. CORRELATION WAS NOT FOUND BETWEEN DDIT3 PROMOTER HYPERMETHYLATION AND THE AGE, SEX, HEMOGLOBIN CONCENTRATION, PLATELET COUNTS, CHROMOSOMAL ABNORMALITIES, BCR/ABL TRANSCRIPT, AND STAGING OF CML PATIENTS (P > 0.05), BUT FOUND BETWEEN DDIT3 PROMOTER HYPERMETHYLATION AND WBC COUNTS OF CML CASES (R = 0.781, P < 0.001). THE LEVEL OF DDIT3 TRANSCRIPT IN CML PATIENTS WAS SIGNIFICANTLY LOWER THAN THAT IN CONTROLS (MEDIAN 3.28 VS 19.69, P < 0.001), HOWEVER, THERE WAS NO DIFFERENCE IN THE LEVEL OF DDIT3 TRANSCRIPT BETWEEN METHYLATION-POSITIVE CML CASES (0.05-65.32, MEDIAN 2.13) AND METHYLATION- NEGATIVE CML CASES (0.12-126.04, MEDIAN 3.92) (P > 0.05). CONCLUSION: OUR RESULTS DEMONSTRATE THAT ABERRANT METHYLATION OF DDIT3 OCCURS IN CML FREQUENTLY. 2010 8 4601 44 NDRG2 MRNA LEVELS AND MIR-28-5P AND MIR-650 ACTIVITY IN CHRONIC LYMPHOCYTIC LEUKEMIA. BACKGROUND: NDRG2 IS IDENTIFIED AS A TUMOR SUPPRESSOR GENE IN MANY TUMORS, AND FUNCTIONS IN CELL PROLIFERATION, DIFFERENTIATION AND APOPTOSIS. RECENT DATA INDICATE THAT NDRG2 EXPRESSION IS UP-REGULATED BY TP53. MOREOVER, PROPOSED MECHANISMS OF NDRG2 INACTIVATION INCLUDE EPIGENETIC SILENCING OF THE NDRG2 PROMOTER AND DOWN-REGULATION BY MICRORNAS (MIRNAS). HOWEVER, FEW STUDIES HAVE EVER BEEN DONE ON THE ROLE OF NDRG2 AND THE NDRG2-REGULATING MIRNAS INTERFERENCE IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). METHODS: NDRG2 AND MICRORNAS MRNA LEVELS IN CLL SUBJECTS WERE ASSESSED BY QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QRT-PCR). THE DUAL-LUCIFERASE REPORTER ASSAY WAS PERFORMED TO DETERMINE NDRG2-RELATED MIRNAS. LOW EXPRESSION OF MATURE EXOGENOUS MIRNAS IN CLL CELLS WAS ESTABLISHED BY TRANSIENT TRANSFECTION. NDRG2 PROTEIN LEVELS IN CLL CELLS WERE DETECTED BY WESTERN BLOT. IN ADDITION, FLOW CYTOMETRY WAS CONDUCTED TO EXAMINE THE APOPTOSIS OF CLL CELLS. RESULTS: LOWER EXPRESSION OF NDRG2 WAS FOUND IN THE B-CELLS FROM 102 CLL PATIENTS COMPARED THE 40 NORMAL SUBJECTS (P < 0.001). PATIENTS WITH ADVANCED BINET STAGE (P = 0.001), HIGH LACTATE DEHYDROGENASE (LDH) LEVEL (P = 0.036), UN-MUTATED IMMUNOGLOBULIN HEAVY CHAIN VARIABLE REGION GENE (IGHV) (P = 0.004) AND THOSE WITH P53 ABERRATIONS (P < 0.001) HAD A MARKEDLY LOWER LEVELS OF NDRG2 MRNA. THIS DECREASE WAS ASSOCIATED WITH BRIEFER TIME-TO-TREATMENT (P = 0.001) AND POORER SURVIVAL (P < 0.001). HIGH EXPRESSION OF MIR-28-5P AND MIR-650 WAS ASSOCIATED WITH BINET B/C STAGE (P = 0.044) AND IGHV UN-MUTATED (P = 0.011), AS WELL AS BINET B/C STAGE (P = 0.013) AND P53 ABERRATIONS (P = 0.037), RESPECTIVELY. INHIBITION OF MIR-28-5P OR MIR-650 COULD INDUCE MORE APOPTOSIS IN CLL CELLS WITH GERMLINE TP53. CONCLUSIONS: NDRG2 MRNA LEVELS MIGHT BE A USEFUL PROGNOSTIC VARIABLE FOR PATIENTS OF CLL AND UP-REGULATING NDRG2 TRANSCRIPTION MAY BE A THERAPY APPROACH IN CLL WITHOUT P53 ABERRATIONS. 2018 9 157 28 ABERRANT METHYLATION OF TUMOUR SUPPRESSOR GENE ADAM12 IN CHRONIC LYMPOCYTIC LEUKEMIA PATIENTS: APPLICATION OF METHYLATION SPECIFIC-PCR TECHNIQUE. OBJECTIVE: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS A COMMON LEUKEMIA AMONG CAUCASIANS BUT RARE IN ASIANS POPULATION. WE POSTULATED THAT ABERRANT METHYLATION EITHER HYPERMETHYLATION OR PARTIAL METHYLATION MIGHT BE ONE OF THE SILENCING MECHANISMS THAT INACTIVATES THE TUMOUR SUPPRESSOR GENES IN CLL. THIS STUDY AIMED TO COMPARE THE METHYLATION STATUS OF TUMOUR SUPPRESSOR GENE, ADAM12, AMONG CLL PATIENTS AND NORMAL INDIVIDUALS. WE ALSO EVALUATED THE ASSOCIATION BETWEEN METHYLATION OF ADAM12 AND CLINICAL AND DEMOGRAPHIC CHARACTERISTICS OF THE PARTICIPANTS. METHODS: A TOTAL OF 25 CLL PATIENTS AND 25 NORMAL INDIVIDUALS WERE RECRUITED IN THIS STUDY. THE METHYLATION STATUS OF ADAM12 WAS DETERMINED USING METHYLATION-SPECIFIC PCR (MSP); WHEREAS, DNA SEQUENCING METHOD WAS APPLIED FOR VALIDATION OF THE MSP RESULTS. RESULTS: AMONG CLL PATIENTS, 12 (48%) WERE PARTIALLY METHYLATED AND 13 (52%) WERE UNMETHYLATED. MEANWHILE, 5 (20%) AND 20 (80.6%) OF HEALTHY INDIVIDUALS WERE PARTIALLY METHYLATED AND UNMETHYLATED, RESPECTIVELY. THERE WAS A STATISTICALLY SIGNIFICANT ASSOCIATION BETWEEN THE STATUS OF METHYLATION AT ADAM12 AND THE PRESENCE OF CLL (P=0.037). CONCLUSION: THE ABERRANT METHYLATION OF ADAM12 FOUND IN THIS STUDY USING MSP ASSAY MAY PROVIDE NEW EXPOSURE TO CLL THAT MAY IMPROVE THE GAPS INVOLVED IN GENETIC EPIGENETIC STUDY IN CLL. 2021 10 5274 19 PROMOTER METHYLATION OF P16 AND EDNRB GENE IN LEUKEMIA PATIENTS IN TAIWAN. BOTH EPIGENETIC AND GENETIC ALTERNATIONS ARE INVOLVED IN CANCER FORMATION. IN THIS STUDY, WE HAVE IDENTIFIED THE METHYLATION FREQUENCY OF P16 AND ENDOTHELIN RECEPTOR TYPE B (EDNRB) OF 26 LEUKEMIA PATIENTS AND 8 RANDOMLY SELECTED NORMAL BLOOD DONORS IN TAIWAN. PROMOTER METHYLATION OF P16 WAS DETECTED IN 85% OF ACUTE LYMPHOCYTIC LEUKEMIA (ALL), 83% IN ACUTE MYELOID LEUKEMIA (AML) WHEREAS NO METHYLATION WAS DETECTED IN CHRONIC MYELOID LEUKEMIA (CML) IN BLAST CRISIS. HYPERMETHYLATION OF EDNRB WAS OBSERVED IN 92% OF ALL, 75% AML AND 100% IN CML IN BLAST CRISIS. NO ABERRANT METHYLATION OF P16 AND EDNRB WAS FOUND IN 8 NORMAL BLOOD DONORS. TAKEN TOGETHER, ABERRANT METHYLATION OF P16 AND EDNRB WAS HIGHLY PREVALENT IN LEUKEMIA PATIENTS IN TAIWAN. 2008 11 156 34 ABERRANT METHYLATION OF THE DEATH-ASSOCIATED PROTEIN KINASE 1 (DAPK1) CPG ISLAND IN CHRONIC MYELOID LEUKEMIA. THE DEATH-ASSOCIATED PROTEIN KINASE 1 (DAPK1) GENE IS A CANDIDATE TUMOR SUPPRESSOR (TSG) AND THE ABNORMAL METHYLATION OF DAPK1 GENE HAS BEEN FOUND IN MANY CARCINOMAS. THE EPIGENETIC CHANGES OF TSGS ARE NOW RECOGNIZED AS A MECHANISM CONTRIBUTING TO THE DEVELOPMENT OF CHRONIC MYELOID LEUKEMIA (CML). TO CLARIFY THE ROLE OF DAPK1 IN CML, WE EXAMINED THE METHYLATION STATUS OF DAPK1 IN 49 PATIENTS WITH CML USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. THE ABERRANT METHYLATION OF THE DAPK1 GENE WAS FOUND IN 25 OF 49 (51.0%) CML CASES, NOT IN ALL CONTROLS. NO CORRELATION WAS FOUND BETWEEN DAPK1 GENE METHYLATION AND THE AGE, HEMATOLOGIC PARAMETERS, CHROMOSOMAL ABNORMALITIES, THE TYPES AND LEVELS OF BCR/ABL TRANSCRIPTS OF CML PATIENTS. HOWEVER, CORRELATION COULD BE OBSERVED BETWEEN THE SEX AND THE STATUS OF DAPK1 METHYLATION IN CML PATIENTS (R = 0.374, P = 0.008). FURTHERMORE, THERE WAS A SIGNIFICANT CORRELATION BETWEEN DAPK1 METHYLATION AND THE STAGES OF CML (R = 0.354, P = 0.013). THE CML PATIENTS IN ACCELERATED PHASE (AP) AND BLAST CRISIS (BC) HAD HIGHER FREQUENCY OF DAPK1 METHYLATION THAN THOSE IN CHRONIC PHASE (CP) (75.0% VS. 34.5%) (CHI(2) = 7.776, P = 0.005). IN ONE PATIENT, THE STATUS OF DAPK1 METHYLATION BECAME POSITIVE ON THE TRANSITION FROM CP TO AP AND BC. THESE RESULTS SUGGESTED THAT DAPK1 PROMOTER METHYLATION MIGHT PLAY A SIGNIFICANT ROLE IN THE PROGRESSION OF CML. 2009 12 4231 37 METHYLATION OF PROTOCADHERIN 10, A NOVEL TUMOR SUPPRESSOR, IS ASSOCIATED WITH POOR PROGNOSIS IN PATIENTS WITH GASTRIC CANCER. BACKGROUND & AIMS: BY USING METHYLATION-SENSITIVE REPRESENTATIONAL DIFFERENCE ANALYSIS, WE IDENTIFIED PROTOCADHERIN 10 (PCDH10), A GENE THAT ENCODES A PROTOCADHERIN AND IS SILENCED IN A TUMOR-SPECIFIC MANNER. WE ANALYZED ITS EPIGENETIC INACTIVATION, BIOLOGICAL EFFECTS, AND PROGNOSTIC SIGNIFICANCE IN GASTRIC CANCER. METHODS: METHYLATION STATUS WAS EVALUATED BY COMBINED BISULFITE RESTRICTION ANALYSIS AND BISULFITE SEQUENCING. THE EFFECTS OF PCDH10 RE-EXPRESSION WERE DETERMINED IN GROWTH, APOPTOSIS, PROLIFERATION, AND INVASION ASSAYS. PCDH10 TARGET GENES WERE IDENTIFIED BY COMPLEMENTARY DNA MICROARRAY ANALYSIS. RESULTS: PCDH10 WAS SILENCED OR DOWN-REGULATED IN 94% (16 OF 17) OF GASTRIC CANCER CELL LINES; EXPRESSION LEVELS WERE RESTORED BY EXPOSURE TO DEMETHYLATING AGENTS. RE-EXPRESSION OF PCDH10 IN MKN45 GASTRIC CANCER CELLS REDUCED COLONY FORMATION IN VITRO AND TUMOR GROWTH IN MICE; IT ALSO INHIBITED CELL PROLIFERATION (P < .01), INDUCED CELL APOPTOSIS (P < .001), AND REPRESSED CELL INVASION (P < .05), UP-REGULATING THE PRO-APOPTOSIS GENES FAS, CASPASE 8, JUN, AND CDKN1A; THE ANTIPROLIFERATION GENE FGFR; AND THE ANTI-INVASION GENE HTATIP2. PCDH10 METHYLATION WAS DETECTED IN 82% (85 OF 104) OF GASTRIC TUMORS COMPARED WITH 37% (38 OF 104) OF PAIRED NONTUMOR TISSUES (P < .0001). IN THE LATTER, PCDH10 METHYLATION WAS HIGHER IN PRECANCEROUS LESIONS (27 OF 45; 60%) THAN IN CHRONIC GASTRITIS SAMPLES (11 OF 59; 19%) (P < .0001). AFTER A MEDIAN FOLLOW-UP PERIOD OF 16.8 MONTHS, MULTIVARIATE ANALYSIS REVEALED THAT PATIENTS WITH PCDH10 METHYLATION IN ADJACENT NONTUMOR AREAS HAD A SIGNIFICANT DECREASE IN OVERALL SURVIVAL. KAPLAN-MEIER SURVIVAL CURVES SHOWED THAT PCDH10 METHYLATION WAS ASSOCIATED SIGNIFICANTLY WITH SHORTENED SURVIVAL IN STAGE I-III GASTRIC CANCER PATIENTS. CONCLUSIONS: PCDH10 IS A GASTRIC TUMOR SUPPRESSOR; ITS METHYLATION AT EARLY STAGES OF GASTRIC CARCINOGENESIS IS AN INDEPENDENT PROGNOSTIC FACTOR. 2009 13 1495 29 DNA HYPERMETHYLATION OF CELL CYCLE (P15 AND P16) AND APOPTOTIC (P14, P53, DAPK AND TMS1) GENES IN PERIPHERAL BLOOD OF LEUKEMIA PATIENTS. ABERRANT DNA METHYLATION OF TUMOR SUPPRESSOR GENES HAS BEEN REPORTED IN ALL MAJOR TYPES OF LEUKEMIA WITH POTENTIAL INVOLVEMENT IN THE INACTIVATION OF REGULATORY CELL CYCLE AND APOPTOSIS GENES. HOWEVER, MOST OF THE PREVIOUS REPORTS DID NOT SHOW THE EXTENT OF CONCURRENT METHYLATION OF MULTIPLE GENES IN THE FOUR LEUKEMIA TYPES. HERE, WE ANALYZED SIX KEY GENES (P14, P15, P16, P53, DAPK AND TMS1) FOR DNA METHYLATION USING METHYLATION SPECIFIC PCR TO ANALYZE PERIPHERAL BLOOD OF 78 LEUKEMIA PATIENTS (24 CML, 25 CLL, 12 AML, AND 17 ALL) AND 24 HEALTHY VOLUNTEERS. IN CML, METHYLATION WAS DETECTED FOR P15 (11%), P16 (9%), P53 (23%) AND DAPK (23%), IN CLL, P14 (25%), P15 (19%), P16 (12%), P53 (17%) AND DAPK (36%), IN AML, P14 (8%), P15 (45%), P53 (9%) AND DAPK (17%) AND IN ALL, P15 (14%), P16 (8%), AND P53 (8%). THIS STUDY HIGHLIGHTED AN ESSENTIAL ROLE OF DAPK METHYLATION IN CHRONIC LEUKEMIA IN CONTRAST TO P15 METHYLATION IN THE ACUTE CASES, WHEREAS TMS1 HYPERMETHYLATION WAS ABSENT IN ALL CASES. FURTHERMORE, HYPERMETHYLATION OF MULTIPLE GENES PER PATIENT WAS OBSERVED, WITH OBVIOUS SELECTIVENESS IN THE 9P21 CHROMOSOMAL REGION GENES (P14, P15 AND P16). INTERESTINGLY, METHYLATION OF P15 INCREASED THE RISK OF METHYLATION IN P53, AND VICE VERSA, BY FIVE FOLDS (P=0.03) INDICATING POSSIBLE SYNERGISTIC EPIGENETIC DISRUPTION OF DIFFERENT PHASES OF THE CELL CYCLE OR BETWEEN THE CELL CYCLE AND APOPTOSIS. THE INVESTIGATION OF MULTIPLE RELATIONSHIPS BETWEEN METHYLATED GENES MIGHT SHED LIGHT ON TUMOR SPECIFIC INACTIVATION OF THE CELL CYCLE AND APOPTOTIC PATHWAYS. 2014 14 3409 36 HOXA4 GENE PROMOTER HYPERMETHYLATION AS AN EPIGENETIC MECHANISM MEDIATING RESISTANCE TO IMATINIB MESYLATE IN CHRONIC MYELOID LEUKEMIA PATIENTS. DEVELOPMENT OF RESISTANCE TO IMATINIB MESYLATE (IM) IN CHRONIC MYELOID LEUKEMIA (CML) PATIENTS HAS EMERGED AS A SIGNIFICANT CLINICAL PROBLEM. THE OBSERVATION THAT INCREASED EPIGENETIC SILENCING OF POTENTIAL TUMOR SUPPRESSOR GENES CORRELATES WITH DISEASE PROGRESSION IN SOME CML PATIENTS TREATED WITH IM SUGGESTS A RELATIONSHIP BETWEEN EPIGENETIC SILENCING AND RESISTANCE DEVELOPMENT. WE HYPOTHESIZE THAT PROMOTER HYPERMETHYLATION OF HOXA4 COULD BE AN EPIGENETIC MECHANISM MEDIATING IM RESISTANCE IN CML PATIENTS. THUS A STUDY WAS UNDERTAKEN TO INVESTIGATE THE PROMOTER HYPERMETHYLATION STATUS OF HOXA4 IN CML PATIENTS ON IM TREATMENT AND TO DETERMINE ITS ROLE IN MEDIATING RESISTANCE TO IM. GENOMIC DNA WAS EXTRACTED FROM PERIPHERAL BLOOD SAMPLES OF 95 CML PATIENTS (38 GOOD RESPONDERS AND 57 RESISTANT) AND 12 NORMAL CONTROLS. ALL SAMPLES WERE BISULFITE TREATED AND ANALYSED BY METHYLATION-SPECIFIC HIGH-RESOLUTION MELT ANALYSIS. COMPARED TO THE GOOD RESPONDERS, THE HOXA4 HYPERMETHYLATION LEVEL WAS SIGNIFICANTLY HIGHER (P = 0.002) IN IM-RESISTANT CML PATIENTS. ON COMPARING THE RISK, HOXA4 HYPERMETHYLATION WAS ASSOCIATED WITH A HIGHER RISK FOR IM RESISTANCE (OR 4.658; 95% CI, 1.673-12.971; P = 0.003). THUS, IT IS REASONABLE TO SUGGEST THAT PROMOTER HYPERMETHYLATION OF HOXA4 GENE COULD BE AN EPIGENETIC MECHANISM MEDIATING IM RESISTANCE IN CML PATIENTS. 2013 15 3448 29 HYPERMETHYLATION OF THE N-MYC DOWNSTREAM-REGULATED GENE 2 PROMOTER IN PERIPHERAL BLOOD MONONUCLEAR CELLS IS ASSOCIATED WITH LIVER FIBROSIS IN CHRONIC HEPATITIS B. DNA METHYLATION IS A FUNDAMENTAL EPIGENETIC MODIFICATION TO REGULATE GENE EXPRESSION. N-MYC DOWNSTREAM-REGULATED GENE (NDRG) 2 IS A CYTOPLASMIC PROTEIN AND PARTICIPATES IN THE PATHOGENESIS OF LIVER FIBROSIS. IN THIS STUDY, THE MRNA EXPRESSION AND METHYLATION STATUS OF NDRG2 WAS EVALUATED IN PATIENTS WITH CHRONIC HEPATITIS B (CHB). THE STUDY INCLUDED 143 CHB PATIENTS AND 65 NORMAL CONTROLS (NC). THE MRNA EXPRESSION OF NDRG2 IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) WAS DETECTED BY QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION. THE METHYLATION STATUS OF THE NDRG2 PROMOTER IN PBMCS WAS DETECTED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. THE NDRG2 MRNA LEVEL WAS LOWER IN THE CHB GROUP THAN IN THE NC GROUP (P < 0.001). METHYLATION FREQUENCY OF THE NDRG2 PROMOTER WAS SIGNIFICANTLY HIGHER IN CHB PATIENTS THAN IN THE NC GROUP (52.44% VS. 26.15%, P < 0.001). IMPORTANTLY, THE RELATIVE EXPRESSION LEVELS OF NDRG2 MRNA WERE SIGNIFICANTLY LOWER IN THE METHYLATED GROUP THAN IN THE UNMETHYLATED GROUP IN BOTH CHB PATIENTS AND NC (P < 0.001). FURTHERMORE, A LOWER MRNA LEVEL AND HYPERMETHYLATION OF NDRG2 WERE ASSOCIATED WITH LIVER FIBROSIS AND INFLAMMATION GRADE IN CHB. THE ASPARTATE AMINOTRANSFERASE-TO-PLATELET RATIO INDEX (APRI) SCORE IS WIDELY USED TO PREDICT LIVER FIBROSIS. THE MRNA EXPRESSION LEVELS AND METHYLATION STATUS OF NDRG2 SHOWED A BETTER SCORE COMPARED TO APRI FOR DISCRIMINATING THE SEVERITY OF LIVER FIBROSIS. IN CONCLUSION, HYPERMETHYLATION OF NDRG2 IN PBMCS WAS CORRELATED WITH DECREASED MRNA EXPRESSION AND WITH LIVER FIBROSIS. THE METHYLATION STATUS OF THE NDRG2 PROMOTER IN PBMCS IS A POTENTIAL NONINVASIVE BIOMARKER TO PREDICT THE SEVERITY OF LIVER FIBROSIS. 2017 16 4246 36 METHYLATION STATUS OF THE T-CADHERIN GENE PROMOTOR IN PERIPHERAL BLOOD MONONUCLEAR CELLS IS ASSOCIATED WITH HBV-RELATED HEPATOCELLULAR CARCINOMA PROGRESSION. DNA METHYLATION IS ONE OF THE EPIGENETIC MECHANISMS TO REGULATE GENE EXPRESSION AND FREQUENTLY OCCURS IN HUMAN CANCER CELLS. T-CADHERIN (CDH13) IS A NEW MEMBER OF THE CADHERIN SUPERFAMILY AND POSSESSES MULTIPLE FUNCTIONS. OUR STUDY INCLUDED 26 NORMAL CONTROLS (NCS), 65 CHRONIC HEPATITIS B PATIENTS (CHB), 14 LIVER CIRRHOSIS PATIENTS (LC) AND 157 HEPATOCELLULAR CARCINOMA PATIENTS (HCC). WE MAINLY FOCUSED ON THE MRNA EXPRESSION AND METHYLATION STATUS OF CDH13 IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS), WHICH WERE DETECTED BY SEMI-QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (RT-QPCR) AND METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) RESPECTIVELY. THE CDH13 MRNA LEVEL WAS LOWER IN HCC, ESPECIALLY IN EARLY-STAGE OF HCC THAN IN NCS AND CHB GROUPS (P < 0.05). METHYLATION FREQUENCY OF THE CDH13 PROMOTER WAS SIGNIFICANTLY HIGHER IN HCC PATIENTS THAN IN THE NCS AND CHB GROUPS (67.52 % VS 0.00 %, P < 0.001, 67.52 % VS 52.31 %, P < 0.05, RESPECTIVELY). CDH13 MRNA LEVEL WAS SIGNIFICANTLY AND RELATIVELY LOWER IN METHYLATED GROUPS THAN IN UNMETHYLATED GROUPS AMONG THE WHOLE PARTICIPANTS. THE METHYLATION LEVEL OF CDH13 PROMOTER IN HCC MIGHT BE INFLUENCED OR PARTLY INFLUENCED BY SOME CRITICAL FACTORS SUCH AS TBIL, ALB AND AFP (P < 0.05). AS AN IMPORTANT FACTOR IN SIGNALING PATHWAY REGULATING BY CDH13 TO PROMOTE CARCINOGENESIS, JNK LEVEL WAS SIGNIFICANTLY HIGHER IN HCC WHICH HAD A HIGHER METHYLATION FREQUENCY THAN IN NCS, CHB AND LC (P < 0.05). FURTHERMORE, THE COMBINATION OF THE METHYLATED CDH13 LEVEL AND AFP LEVEL SHOWED A BETTER SCORE: AUC = 0.796 (SE = 0.031, 95 %CI 0.735-0.857; P < 0.001) IN MALE AND AUC = 0.832 (SE = 0.057, 95 %CI 0.721-0.944; P < 0.001) IN FEMALE COMPARED TO AFP ALONE FOR DIAGNOSING HCC FROM NCS, CHB AND LC. THE METHYLATION OF CDH13 PROMOTER WAS AN INDEPENDENT PREDICTOR FOR ASSESSING THE PROGNOSIS OF HCC PATIENTS (R=-1.378 P < 0.05). IN CONCLUSION, HYPERMETHYLATION OF CDH13 IN PBMCS WAS ASSOCIATED WITH THE UNDEREXPRESSION OF MRNA AND THE HIGH RISK OF HCC. THE METHYLATION STATUS OF THE CDH13 PROMOTER IN PBMCS WAS A POTENTIAL NONINVASIVE BIOMARKER TO PREDICT THE PROGNOSIS OF HCC PATIENTS. 2020 17 6793 34 [DOWN-REGULATION OF TRANSCRIPTION FACTOR PU.1 VIA ABNORMAL EPIGENETIC MODIFICATION IN CHRONIC MYELOID LEUKEMIA]. OBJECTIVE: TO INVESTIGATE THE UNDERLYING MECHANISM AND CLINICAL SIGNIFICANCE OF PU.1 DOWN-EXPRESSION IN CHRONIC MYELOID LEUKEMIA (CML) PATIENTS. METHODS: DIFFERENT METHYLATION STATUS OF PU.1 PROMOTER REGION CONTAINING 20 CPG ISLANDS IN NORMAL INDIVIDUALS, CML CHRONIC PHASE AND BLAST CRISIS PATIENTS, COMPLETE CYTOGENETIC REMISSION PATIENTS AFTER IMATINIB TREATMENT, AND BLAST CRISIS BONE MARROW K562 CML CELLS WAS DETECTED BY BISULFITE SEQUENCING. SEMI-QUANTITATIVE PCR WAS USED TO DETECT THE PU.1 MRNA EXPRESSION IN NORMAL CONTROLS, CML CHRONIC PHASE AND BLAST CRISIS PATIENTS, AND BLAST CRISIS BONE MARROW K562 CML CELLS. INDIRECT IMMUNE FLUORESCENCE AND WESTERN BLOT WERE USED TO ANALYZE THE EXPRTESSION OF PU.1 PROTEIN IN NORMAL INDIVIDUALS, CML CHRONIC PHASE AND BLAST CRISIS PATIENTS, AND BLAST CRISIS BONE MARROW K562 CML CELLS. RESULTS: ABERRANT METHYLATION IN THE PROMOTER REGION OF TRANSCRIPTION FACTOR PU.1 WAS FOUND IN BOTH CML CHRONIC PHASE AND BLAST CRISIS PHASE BONE MARROW CELLS, AS WELL AS IN CML BLAST K562 CELLS. DOWN-EXPRESSION OF PU.1 MRNA AND PROTEIN LEVELS WAS FOUND IN ABOVE CELLS. NO METHYLATION IN THE PROMOTER REGION OF PU.1 WAS OBSERVED IN NORMAL INDIVIDUALS, AND THE PU.1 MRNA AND PROTEIN EXPRESSIONS WERE NOT REDUCED AT ALL. FURTHERMORE, HIGH METHYLATION STATUS OF BONE MARROW CELLS WAS EVEN OBSERVED IN THE CML PATIENTS WHO ACQUIRED COMPLETE CYTOGENETIC REMISSION. CONCLUSIONS: THE RESULTS OF OUR STUDY INDICATE THAT THE EPIGENETIC MODIFICATION OF PU.1 IN CML PATIENTS AND K562 CELL LINE MIGHT BE RESPONSIBLE FOR THE DOWN-EXPRESSION OF PU.1. THE DATA SUGGEST THAT ABERRANT METHYLATION OF PU.1 PLAYS A ROLE IN CML PATHOGENESIS, THEREFORE, IT MIGHT SERVE AS A USEFUL BIOMARKER AND POTENTIAL TARGET IN THERAPY FOR CHRONIC MYELOID LEUKEMIA. 2012 18 1968 32 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 19 1433 31 DIFFERENTIAL GENOME-WIDE ARRAY-BASED METHYLATION PROFILES IN PROGNOSTIC SUBSETS OF CHRONIC LYMPHOCYTIC LEUKEMIA. GLOBAL HYPOMETHYLATION AND REGIONAL HYPERMETHYLATION ARE WELL-KNOWN EPIGENETIC FEATURES OF CANCER; HOWEVER, IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), STUDIES ON GENOME-WIDE EPIGENETIC MODIFICATIONS ARE LIMITED. HERE, WE ANALYZED THE GLOBAL METHYLATION PROFILES IN CLL, BY APPLYING HIGH-RESOLUTION METHYLATION MICROARRAYS (27,578 CPG SITES) TO 23 CLL SAMPLES, BELONGING TO THE IMMUNOGLOBULIN HEAVY-CHAIN VARIABLE (IGHV) MUTATED (FAVORABLE) AND IGHV UNMUTATED/IGHV3-21 (POOR-PROGNOSTIC) SUBSETS. OVERALL, RESULTS DEMONSTRATED SIGNIFICANT DIFFERENCES IN METHYLATION PATTERNS BETWEEN THESE SUBGROUPS. SPECIFICALLY, IN IGHV UNMUTATED CLL, WE IDENTIFIED METHYLATION OF 7 KNOWN OR CANDIDATE TUMOR SUPPRESSOR GENES (EG, VHL, ABI3, AND IGSF4) AS WELL AS 8 UNMETHYLATED GENES INVOLVED IN CELL PROLIFERATION AND TUMOR PROGRESSION (EG, ADORA3 AND PRF1 ENHANCING THE NUCLEAR FACTOR-KAPPAB AND MITOGEN-ACTIVATED PROTEIN KINASE PATHWAYS, RESPECTIVELY). IN CONTRAST, THESE LATTER GENES WERE SILENCED BY METHYLATION IN IGHV MUTATED PATIENTS. THE ARRAY DATA WERE VALIDATED FOR SELECTED GENES USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION, QUANTITATIVE REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION, AND BISULFITE SEQUENCING. FINALLY, THE SIGNIFICANCE OF DNA METHYLATION IN REGULATING GENE PROMOTERS WAS SHOWN BY REINDUCING 4 METHYLATED TUMOR SUPPRESSOR GENES (EG, VHL AND ABI3) IN IGHV UNMUTATED SAMPLES USING THE METHYL-INHIBITOR 5-AZA-2'-DEOXYCYTIDINE. TAKEN TOGETHER, OUR DATA FOR THE FIRST TIME REVEAL DIFFERENCES IN GLOBAL METHYLATION PROFILES BETWEEN PROGNOSTIC SUBSETS OF CLL, WHICH MAY UNFOLD EPIGENETIC SILENCING MECHANISMS INVOLVED IN CLL PATHOGENESIS. 2010 20 2847 24 FREQUENT P15 PROMOTER METHYLATION IN TUMOR AND PERIPHERAL BLOOD FROM HEPATOCELLULAR CARCINOMA PATIENTS. WE PROSPECTIVELY ANALYZED P15 METHYLATION PATTERNS IN 25 SURGICALLY RESECTED TUMORS AND 130 PLASMA, SERUM, AND BUFFY COAT SAMPLES FROM HEPATOCELLULAR CARCINOMA (HCC) PATIENTS, CONTROLS WITH CHRONIC HEPATITIS/CIRRHOSIS, AND HEALTHY SUBJECTS. USING METHYLATION-SPECIFIC PCR, WE DEMONSTRATED FOR THE FIRST TIME P15 PROMOTER METHYLATION IN 64% OF TUMORS AND 25% (4 OF 16) OF PATIENTS' PLASMA AND SERUM SAMPLES. CONCURRENT P15 AND P16 METHYLATION WAS SHOWN IN 48% OF TUMORS, AND P15/P16 METHYLATION WAS DETECTED IN THE PLASMA/SERUM OF 92% (11 OF 12) OF PATIENTS. OF NOTE, 75% OF 12 PATIENTS WITH CONCURRENT TUMOR METHYLATION DEVELOPED CLINICAL METASTASIS/RECURRENCE (P = 0.027). IN BUFFY COAT SAMPLES, P15 METHYLATION WAS DETECTED IN ALL EIGHT PATIENTS WITH TUMOR P15 METHYLATION, SUGGESTING THE PRESENCE OF CIRCULATING TUMOR CELLS. NONE OF THE CONTROL SAMPLES WERE METHYLATION POSITIVE. OUR DATA UNDERSCORE THE IMPORTANT ROLE(S) OF P15 AND P16 METHYLATION IN HEPATOCARCINOGENESIS AND TUMOR PROGRESSION. AMONG 92% (23 OF 25) OF PATIENTS WITH TUMOR P15/P16 METHYLATION, CIRCULATING TUMOR DNA AND HCC CELLS WERE DETECTED IN THE PERIPHERAL BLOOD OF 87% (20 OF 23) OF PATIENTS. THE COMBINATION OF THESE EPIGENETIC MARKERS MAY PROVE VALUABLE FOR NONINVASIVE HCC DIAGNOSIS AND DISEASE MONITORING. 2000