1 5564 90 ROLE OF HYPERMETHYLATION OF DAP-KINASE CPG ISLAND IN THE DEVELOPMENT OF THYROID LYMPHOMA. DEATH-ASSOCIATED PROTEIN-KINASE (DAP-KINASE) IS A SERINE/THREONINE KINASE WITH A DEATH DOMAIN THAT IS INVOLVED IN APOPTOSIS INDUCED BY INTERFERON-GAMMA, TNF-ALPHA, AND FAS LIGAND. EPIGENETIC DOWN-REGULATION OF DAP-KINASE GENE EXPRESSION BY HYPERMETHYLATION OF ITS PROMOTER REGION WAS REPORTED IN B-CELL MALIGNANCIES. PREVIOUS PATHOEPIDEMIOLOGIC STUDIES INDICATED THAT THYROID LYMPHOMA (TL) EVOLVES AMONG ACTIVE LYMPHOID CELLS IN CHRONIC LYMPHOCYTIC THYROIDITIS (CLTH). WITH USE OF METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION, THE METHYLATION STATUS OF DAP-KINASE CPG ISLAND WAS EXAMINED IN THYROID LESIONS OF 19 CASES WITH TL AND 9 WITH CLTH. THE FREQUENCY OF METHYLATION WAS HIGHER IN TL CASES (16 OF 19, 84.2%) THAN IN CLTH CASES (2 OF 9, 22.2%) (P < 0.01). DNA EXTRACTED FROM PERIPHERAL BLOOD LEUKOCYTES FROM TL AND CLTH CASES NEVER SHOWED METHYLATION, INDICATING THAT THE METHYLATION OCCURRED SOMATICALLY IN THE LESIONAL LYMPHOCYTES IN THYROID. THESE FINDINGS SUGGESTED THAT METHYLATION OF THE DAP-KINASE PROMOTER REGION MIGHT BE INVOLVED IN THE DEVELOPMENT OF TL FROM CLTH. 2000 2 6831 84 [HYPERMETHYLATION OF DAP-KINASE GENE CPG ISLAND IN MALIGNANT LYMPHOMA WITH B-CELL PHENOTYPE]. DEATH-ASSOCIATED PROTEIN-KINASE(DAP-KINASE) IS A PRO-APOPTOTIC SERINE/THREONINE KINASE WITH A DEATH DOMAIN, WHICH IS INVOLVED IN APOPTOSIS INDUCED BY INTERFERON-GAMMA, TUMOR NECROSIS FACTOR-ALPHA, AND FAS LIGAND. EPIGENETIC DOWN-REGULATION OF DAP-KINASE GENE EXPRESSION BY HYPERMETHYLATION OF ITS PROMOTER REGION WAS REPORTED IN CERTAIN KINDS OF MALIGNANCIES. PREVIOUS PATHO-EPIDEMIOLOGICAL STUDIES INDICATED THAT THYROID LYMPHOMA(TL) EVOLVES AMONG ACTIVE LYMPHOID CELLS IN CHRONIC LYMPHOCYTIC THYROIDITIS(CLTH). WITH THE USE OF METHYLATION SPECIFIC POLYMERASE CHAIN REACTION, METHYLATION STATUS OF DAP-KINASE CPG ISLAND WAS EXAMINED IN THYROID LESIONS OF 19 CASES WITH TL AND 9 WITH CLTH. FREQUENCY OF METHYLATION WAS HIGHER IN TL CASES(16 OF 19, 84.2%) THAN IN CLTH CASES(2 OF 9, 22.2%) (P < 0.01). DNA EXTRACTED FROM PERIPHERAL BLOOD LEUKOCYTES FROM TL AND CLTH CASES NEVER SHOWED METHYLATION, INDICATING THAT THE METHYLATION OCCURRED SOMATICALLY IN LESIONAL LYMPHOCYTES IN THE THYROID. WE ALSO EXAMINED THE METHYLATION STATUS OF DAP-KINASE GENE IN 16 CASES OF T-CELL MALIGNANCIES INCLUDING EIGHT ADULT T-CELL LEUKEMIA/LYMPHOMA AND 24 NK/T-CELL, 34 B-CELL, AND TWO IMMUNOPHENOTYPICALLY UNDETERMINED LYMPHOMAS. FREQUENCY OF METHYLATION WAS HIGHER IN B-CELL(27 OF 34, 79.4%) THAN IN T-CELL MALIGNANCIES(EIGHT OF 16, 50%) (P < 0.05). FIFTEEN OF 24(62.5%) NK/T-CELL LYMPHOMAS SHOWED DNA METHYLATION. HEMATOPOIETIC CELL LINES WITH A METHYLATED GENE WERE RESISTANT TO APOPTOSIS. TREATMENT OF THE CELLS WITH A DEMETHYLATING AGENT RESTORED APOPTOTIC CELL DEATH IN ONE B-CELL LYMPHOMA CELL LINE WITH DNA METHYLATION. OUR RESULTS SUGGESTED THAT SUPPRESSION OF DAP-KINASE EXPRESSION BY DNA METHYLATION MIGHT PLAY A ROLE IN THE DEVELOPMENT OF B-CELL MALIGNANCIES. 2001 3 4231 30 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 4 4548 29 MUTATION ANALYSIS OF THE FAS AND TNFR APOPTOTIC CASCADE GENES IN HEMATOLOGICAL MALIGNANCIES. OBJECTIVE: THE EXISTENCE OF PROPERLY FUNCTIONING APOPTOTIC PATHWAYS IS OF UTMOST IMPORTANCE IN THE MAINTENANCE OF A NORMAL CELL COUNT. SEVERAL GROUPS HAVE SEARCHED FOR MUTATIONS IN THE FAS RECEPTOR, A WELL-CHARACTERIZED APOPTOTIC PROTEIN CARRYING A DEATH DOMAIN, AND REPORTED THE EXISTENCE OF RARE MUTATIONS IN MULTIPLE MYELOMA, T-ACUTE LYMPHOBLASTIC LEUKEMIA (T-ALL), AND ADULT T-CELL LEUKEMIA. OUR AIM WAS TO EXPAND THESE SEARCHES BY LOOKING FOR MUTATIONS IN THE DEATH DOMAINS OF FAS, FADD, TNFR, TRADD, AND RIP, IN THE PROMOTER REGION OF FAS, AND IN THE PROTEASE DOMAIN OF CASPASE 10, IN A LARGER VARIETY OF HEMATOLOGICAL MALIGNANCIES, SOME OF WHICH EXPRESS AN APOPTOSIS-RESISTANT PHENOTYPE. METHODS: WE EXTRACTED RNA AND DNA SAMPLES FROM 92 HEMATOLOGICAL MALIGNANCIES: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL; 31 CASES), CHRONIC MYELOGENOUS LEUKEMIA (CML; 28 CASES), ESSENTIAL THROMBOCYTHEMIA (ET; 8 CASES), ACUTE LYMPHOCYTIC LEUKEMIA (ALL; 6 CASES), ACUTE MYELOBLASTIC LEUKEMIA (AML; 6 CASES), HAIRY-CELL LEUKEMIA (HCL; 3 CASES), BURKITT'S LYMPHOMA (3 CASES), POLYCYTHEMIA VERA (PV; 3 CASES), MYELOFIBROSIS (2 CASES), AND CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML; 2 CASES) AND PERFORMED PCR-SSCP AND SEQUENCE ANALYSIS ON THESE SAMPLES. RESULTS: FIVE POLYMORPHIC PATTERNS WERE FOUND: THREE IN THE DEATH DOMAIN OF THE FAS GENE IN CML PATIENTS, ONE IN THE PROMOTER OF THIS GENE IN A CLL PATIENT, AND THE FIFTH IN THE DEATH DOMAIN OF THE TRADD GENE IN A CML PATIENT. NO MUTATIONS, ALTERING AMINO ACIDS, WERE FOUND IN THESE GENES IN ANY OF THE AFOREMENTIONED MALIGNANCIES. CONCLUSIONS: THESE OBSERVATIONS IMPLY THAT MUTATIONS IN THE DEATH DOMAINS OF FAS, FADD, TNFR, TRADD, AND RIP AND IN THE PROTEASE DOMAIN OF CASPASE 10 ARE NOT A MAJOR CAUSE FOR FAILURE OF APOPTOSIS IN HEMATOLOGICAL MALIGNANCIES, MAINLY CML AND CLL. REGULATORY AND EPIGENETIC ABNORMALITIES IN THESE APOPTOTIC CASCADE MEMBERS AND ABERRATIONS IN OTHER COMPONENTS OF ALL DEATH MACHINERY SHOULD BE LOOKED FOR. 2001 5 614 24 BINGE ALCOHOL-INDUCED MICROVESICULAR LIVER STEATOSIS AND INJURY ARE ASSOCIATED WITH DOWN-REGULATION OF HEPATIC HDAC 1, 7, 9, 10, 11 AND UP-REGULATION OF HDAC 3. BACKGROUND: BINGE, AS WELL AS CHRONIC, ALCOHOL CONSUMPTION AFFECTS GLOBAL HISTONE ACETYLATION LEADING TO CHANGES IN GENE EXPRESSION. IT IS BECOMING INCREASINGLY EVIDENT THAT THESE HISTONE-ASSOCIATED EPIGENETIC MODIFICATIONS PLAY AN IMPORTANT ROLE IN THE DEVELOPMENT OF ALCOHOL-MEDIATED HEPATIC INJURY. METHODS: C57BL/6 MICE WERE GAVAGED 3 TIMES (12-HOUR INTERVALS) WITH ETHANOL (ETOH; 4.5 G/KG). HEPATIC HISTONE DEACETYLASE (HDAC) MRNAS WERE ASSESSED BY QRT-PCR. TOTAL HDAC ACTIVITY WAS ESTIMATED BY A COLORIMETRIC HDAC ACTIVITY/INHIBITION ASSAY. HISTONE ACETYLATION LEVELS WERE EVALUATED BY WESTERN BLOT. LIVER STEATOSIS AND INJURY WERE EVALUATED BY HISTOPATHOLOGY, PLASMA AMINOTRANSFERASE (ALT) ACTIVITY, AND LIVER TRIGLYCERIDE ACCUMULATION. EXPRESSION OF FATTY ACID SYNTHASE (FAS) AND CARNITINE PALMITOYL TRANSFERASE 1A (CPT1A) WAS ALSO EXAMINED. HDAC 9 ASSOCIATION WITH FAS PROMOTER WAS ANALYZED. RESULTS: BINGE ALCOHOL EXPOSURE RESULTED IN ALTERATIONS OF HEPATIC HDAC MRNA LEVELS. DOWN-REGULATION OF HDAC CLASS I (HDAC 1), CLASS II (HDAC 7, 9, 10), AND CLASS IV (HDAC 11) AND UP-REGULATION OF HDAC CLASS I (HDAC 3) GENE EXPRESSION WERE OBSERVED. CORRESPONDENT TO THE DECREASE IN HDAC ACTIVITY, AN INCREASE IN HEPATIC HISTONE ACETYLATION WAS OBSERVED. THESE MOLECULAR EVENTS WERE ASSOCIATED WITH MICROVESICULAR HEPATIC STEATOSIS AND INJURY CHARACTERIZED BY INCREASED HEPATIC TRIGLYCERIDES (48.02 +/- 3.83 VS. 19.90 +/- 3.48 MG/G LIVER, P < 0.05) AND ELEVATED PLASMA ALT ACTIVITY (51.98 +/- 6.91 VS. 20.8 +/- 0.62 U/L, P < 0.05). HEPATIC STEATOSIS WAS ASSOCIATED WITH AN INCREASE IN FAS AND A DECREASE IN CPT1A MRNA AND PROTEIN EXPRESSION. FAS PROMOTER ANALYSIS REVEALED THAT BINGE ETOH TREATMENT DECREASED HDAC 9 OCCUPANCY AT THE FAS PROMOTER RESULTING IN ITS TRANSCRIPTIONAL ACTIVATION. CONCLUSIONS: DEREGULATION OF HEPATIC HDAC EXPRESSION LIKELY PLAYS A MAJOR ROLE IN THE BINGE ALCOHOL-INDUCED HEPATIC STEATOSIS AND LIVER INJURY BY AFFECTING LIPOGENESIS AND FATTY ACID BETA-OXIDATION. 2012 6 2185 30 EPIGENETIC MECHANISMS UNDERLYING HIV-INFECTION INDUCED SUSCEPTIBILITY OF CD4+ T CELLS TO ENHANCED ACTIVATION-INDUCED FASL EXPRESSION AND CELL DEATH. BACKGROUND: CHRONIC IMMUNE ACTIVATION AND CD4 T CELL DEPLETION ARE SIGNIFICANT PATHOGENIC FEATURES OF HIV INFECTION. EXPRESSION OF FAS LIGAND (FASL), A KEY MEDIATOR OF ACTIVATION-INDUCED CELL DEATH IN T CELLS, IS ELEVATED IN PEOPLE LIVING WITH HIV-1 INFECTION (PLWH). HOWEVER, THE EPIGENETIC MECHANISMS UNDERLYING THE ENHANCED INDUCTION OF FASL EXPRESSION IN CD4 T LYMPHOCYTES IN PLWH ARE NOT COMPLETELY ELUCIDATED. HENCE, THE CURRENT WORK EXAMINED THE EFFECT OF HIV INFECTION ON FASL PROMOTER-ASSOCIATED HISTONE MODIFICATIONS AND TRANSCRIPTIONAL REGULATION IN CD4 T LYMPHOCYTES IN PLWH. METHOD: FLOW CYTOMETRIC ANALYSIS WAS PERFORMED TO EXAMINE THE FAS-FASL EXPRESSION ON TOTAL CD4 T CELLS AND NAIVE/MEMORY CD4 T CELL SUBSETS. EPIGENETIC FASL PROMOTER HISTONE MODIFICATIONS WERE INVESTIGATED BY CHROMATIN IMMUNOPRECIPITATION-QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION ANALYSIS USING FRESHLY ISOLATED TOTAL CD4 T LYMPHOCYTES FROM HIV-1 INFECTED AND NONINFECTED INDIVIDUALS. RESULTS: ALL NAIVE/MEMORY CD4 T CELL SUBSETS FROM PLWH SHOWED MARKEDLY GREATER FREQUENCY OF FASL EXPRESSION. NOTABLY, EXAMINATION OF FUNCTIONAL OUTCOME OF FASL/FAS CO-EXPRESSION DEMONSTRATED THE PREFERENTIAL SUSCEPTIBILITY OF TCM AND TEM SUBSETS TO ACTIVATION-INDUCED APOPTOSIS. IMPORTANTLY, THESE CD4 T CELLS COLLECTIVELY DEMONSTRATED A DISTINCT FASL PROMOTER HISTONE PROFILE INVOLVING A COORDINATED CROSS-TALK BETWEEN HISTONE H3 MODIFICATIONS LEADING TO ENHANCED FASL GENE EXPRESSION. SPECIFICALLY, LEVELS OF TRANSCRIPTIONALLY PERMISSIVE HISTONE H3K4-TRIMETHYLATION (H3K4ME3) AND HISTONE H3K9-ACETYLATION (H3K9AC) WERE INCREASED, WITH A CONCOMITANT DECREASE IN THE REPRESSIVE H3K9-TRIMETHYLATION (H3K9ME3). CONCLUSION: THE PRESENT WORK DEMONSTRATES THAT EPIGENETIC MECHANISMS INVOLVING PROMOTER-HISTONE MODIFICATIONS REGULATE TRANSCRIPTIONAL COMPETENCE AND FASL EXPRESSION IN CD4 T CELLS FROM PLWH AND RENDER THEM SUSCEPTIBLE TO ACTIVATION-INDUCED CELL DEATH. 2021 7 2133 24 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 8 2132 24 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 9 4601 32 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 10 5278 29 PROMOTER METHYLATION-MEDIATED INACTIVATION OF PCDH10 IN ACUTE LYMPHOBLASTIC LEUKEMIA CONTRIBUTES TO CHEMOTHERAPY RESISTANCE. PCDH10 HAS BEEN IMPLICATED AS A TUMOR SUPPRESSOR, SINCE EPIGENETIC ALTERATIONS OF THIS GENE HAVE BEEN NOTED IN MULTIPLE TUMOR TYPES. HOWEVER, TO DATE, STUDIES REGARDING ITS ROLE IN ACUTE AND CHRONIC LEUKEMIAS ARE LACKING. HERE, WE HAVE INVESTIGATED THE PRESENCE OF PROMOTER HYPERMETHYLATION OF TWO CPG ISLANDS OF THE PCDH10 GENE BY METHYLATION-SPECIFIC PCR IN 215 CASES OF VARIOUS SUBSETS OF MYELOID- AND LYMPHOID-LINEAGE LEUKEMIAS. WE FOUND THAT PCDH10 PROMOTER HYPERMETHYLATION WAS FREQUENT IN BOTH B-CELL (81.9%) AND T-CELL (80%) ACUTE LYMPHOBLASTIC LEUKEMIA (ALL), WHILE IT WAS PRESENT IN LOW FREQUENCY IN MOST SUBTYPES OF MYELOID LEUKEMIAS (25.9%) AND RARE IN CHRONIC MYELOID LEUKEMIA (2.2%). PCDH10 EXPRESSION WAS DOWNREGULATED VIA PROMOTER HYPERMETHYLATION IN PRIMARY ALL SAMPLES (N = 4) AND LEUKEMIA CELL LINES (N = 11). THE TRANSCRIPTIONAL REPRESSION CAUSED BY PCDH10 METHYLATION COULD BE RESTORED BY PHARMACOLOGIC INHIBITION OF DNA METHYLTRANSFERASES. ALL CELL LINES HARBORING METHYLATION-MEDIATED INACTIVATION OF PCDH10 WERE LESS SENSITIVE TO COMMONLY USED LEUKEMIA-SPECIFIC DRUGS SUGGESTING THAT PCDH10 METHYLATION MIGHT SERVE AS A BIOMARKER OF CHEMOTHERAPY RESPONSE. OUR RESULTS DEMONSTRATE THAT PCDH10 IS A TARGET OF EPIGENETIC SILENCING IN ALL, A PHENOMENON THAT MAY IMPACT LYMPHOID-LINEAGE LEUKEMOGENESIS, SERVE AS AN INDICATOR OF DRUG RESISTANCE AND MAY ALSO HAVE POTENTIAL IMPLICATIONS FOR TARGETED EPIGENETIC THERAPY. 2011 11 4903 22 P16 PROMOTER HYPERMETHYLATION IN HUMAN HEPATOCELLULAR CARCINOMA WITH OR WITHOUT HEPATITIS VIRUS INFECTION. BACKGROUND: EPIGENETIC ALTERATION THROUGH METHYLATION IS ONE OF THE MOST IMPORTANT STEPS IN CARCINOGENESIS. HOWEVER, THE RELATION BETWEEN HEPATITIS VIRUS INFECTION AND EPIGENETIC ALTERATIONS IS POORLY UNDERSTOOD. METHODS: SIXTEEN PATIENTS WITHOUT HEPATITIS B VIRUS (HBV) AND HEPATITIS C VIRUS (HCV) AND 35 PATIENTS WITH HBV OR HCV WHO UNDERWENT LIVER RESECTION FOR HEPATOCELLULAR CARCINOMA (HCC) WERE STUDIED. MUTATION OF P53 WAS DETECTED BY DIRECT SEQUENCING. METHYLATION STATUS OF P16 WAS EVALUATED IN TUMOR AND NONCANCEROUS LIVER TISSUES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION. RESULTS: IN HCC WITHOUT HBV AND HCV, P53 MUTATIONS WERE DETECTED IN 5 (31%) OF 16 HCCS. METHYLATION OF P16 PROMOTER WAS DETECTED IN 2 (25%) OF 8 MODERATELY DIFFERENTIATED HCCS, 6 (75%) OF 8 POORLY DIFFERENTIATED HCCS, AND NONE OF 16 NONCANCEROUS TISSUE SPECIMENS. IN HCC WITH HBV OR HCV, P53 MUTATIONS WERE DETECTED IN 8 (23%) OF 35 HCCS. METHYLATION OF P16 PROMOTER WAS DETECTED IN 2 (100%) OF 2 WELL-DIFFERENTIATED HCCS, 13 (76%) OF 17 MODERATELY DIFFERENTIATED HCCS, 12 (75%) OF 16 POORLY DIFFERENTIATED HCCS, AND 9 (26%) OF 35 NONCANCEROUS LIVER TISSUE SPECIMENS. CONCLUSIONS: OUR RESULTS SUGGEST THAT HEPATITIS VIRUSES MIGHT INDUCE METHYLATION OF P16 PROMOTER IN LIVER WITH CHRONIC INFLAMMATION, BEFORE APPEARANCE OF HCC. 2004 12 2426 24 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 13 2440 30 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 14 2842 28 FREQUENT CONCOMITANT EPIGENETIC SILENCING OF SOX1 AND SECRETED FRIZZLED-RELATED PROTEINS (SFRPS) IN HUMAN HEPATOCELLULAR CARCINOMA. BACKGROUND AND AIM: EXCEPT FOR GENETIC MUTATIONS, EPIGENETIC CHANGES ARE ALSO INVOLVED IN THE DEVELOPMENT OF HUMAN CANCERS. RECENTLY, WE HAVE IDENTIFIED SOX1, SRY (SEX DETERMINING REGION Y)-BOX 1, IS HYPERMETHYLATED IN CERVICAL CANCER AND OVARIAN CANCER. THEREFORE, WE INVESTIGATED WHETHER PROMOTER HYPERMETHYLATION OF SOX1 IS COMMON IN HEPATOCELLULAR CARCINOMA (HCC). METHODS: WE USED METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MS-PCR) AND BISULFITE SEQUENCING TO ANALYZE THE METHYALTION LEVEL OF THE SOX1 PROMOTER IN SEVEN HCC CELL LINES, 54 CLINICAL HCCS, 42 CIRRHOTIC LIVERS, 21 LIVERS WITH CHRONIC HEPATITIS, AND 15 CONTROL LIVERS. THEN, WE EMPLOYED QUANTITATIVE MS-PCR (QMSP) TO VALIDATE IN AN INDEPENDENT SET OF SAMPLES (60 PAIRED HCCS AND 30 CONTROL LIVERS). FINALLY, WE USED LUCIFERASE REPORTER AND COLONY FORMATION ASSAY TO CHECK THE EFFECT OF SOX1 IN HCC. RESULTS: PROMOTER METHYLATION OF SOX1 WAS SIGNIFICANTLY FREQUENT IN HCC CELL LINES AND CLINICAL HCCS, CIRRHOTIC LIVERS, BUT NOT IN CONTROL LIVERS (P < 0.0001). THERE IS A SIGNIFICANT CORRELATION BETWEEN DOWNREGULATION OF SOX1 EXPRESSION AND PROMOTER METHYLATION. QMSP RESULTS CONFIRMED THAT PROMOTER HYPERMETHYLATION OF SOX1 IS SIGNIFICANTLY MORE FREQUENT IN HCCS THAN CONTROL LIVERS (P < 0.0001). THE FREQUENCY OF SOX1 METHYLATION IN PATIENTS WITH SECRETED FRIZZLED-RELATED PROTEINS (SFRPS) METHYLATION IS SIGNIFICANTLY HIGHER THAN IN PATIENTS WITHOUT SFRPS METHYLATION (P < 0.0001). FURTHERMORE, ECTOPIC EXPRESSION OF SOX1 COULD SUPPRESS T-CELL FACTOR-DEPENDENT TRANSCRIPTIONAL ACTIVITY AND COLONY FORMATION NUMBER IN HCCS. CONCLUSIONS: CONCOMITANT EPIGENETIC SILENCING OF SOX1 AND SFRPS THROUGH PROMOTER HYPERMETHYLATION IS FREQUENT IN HCCS, AND THIS MIGHT CONTRIBUTE TO ABNORMAL ACTIVATION OF CANONICAL WNT SIGNAL PATHWAY. 2013 15 1495 25 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 16 6688 22 VALPROATE SYNERGIZES WITH PURINE NUCLEOSIDE ANALOGUES TO INDUCE APOPTOSIS OF B-CHRONIC LYMPHOCYTIC LEUKAEMIA CELLS. RESISTANCE TO CHEMOTHERAPY AND DRUG TOXICITY ARE TWO MAJOR CONCERNS OF CHRONIC LYMPHOCYTIC LEUKAEMIA (B-CLL) TREATMENT BY PURINE NUCLEOSIDE ANALOGUES (PNA, I.E. FLUDARABINE AND CLADRIBINE). WE HYPOTHESIZED THAT TARGETING EPIGENETIC CHANGES MIGHT ADDRESS THESE ISSUES AND EVALUATED THE EFFECT OF THE HISTONE DEACETYLASE INHIBITOR VALPROATE (VPA) AT A CLINICALLY RELEVANT CONCENTRATION. VPA ACTED IN A HIGHLY SYNERGISTIC/ADDITIVE MANNER WITH FLUDARABINE AND CLADRIBINE TO INDUCE APOPTOSIS OF B-CLL CELLS. IMPORTANTLY, VPA ALSO RESTORED SENSITIVITY TO FLUDARABINE IN B CELLS FROM POOR PROGNOSIS CLL PATIENTS WHO BECAME RESISTANT TO CHEMOTHERAPY. MECHANISM OF APOPTOSIS INDUCED BY VPA ALONE OR COMBINED WITH FLUDARABINE OR TO CLADRIBINE WAS CASPASE-DEPENDENT AND INVOLVED THE EXTRINSIC PATHWAY. VPA, BUT NEITHER FLUDARABINE NOR CLADRIBINE, ENHANCED THE PRODUCTION OF REACTIVE OXYGEN SPECIES (ROS) AND INHIBITION OF ROS WITH N-ACETYLCYSTEINE DECREASES APOPTOSIS OF CLL CELLS. VPA STIMULATES HYPERPHOSPHORYLATION OF P42/P44 ERK, CYTOCHROME C RELEASE AND OVEREXPRESSION OF BAX AND FAS. TOGETHER, OUR DATA INDICATE THAT VPA MAY AMELIORATE THE OUTCOME OF PNA-BASED THERAPEUTIC PROTOCOLS AND PROVIDE A POTENTIAL ALTERNATIVE TREATMENT IN BOTH THE RELAPSED AND FRONT-LINE RESISTANT PATIENTS AND IN PATIENTS WITH HIGH RISK FEATURES. 2009 17 2326 27 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY. 2018 18 2131 28 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 19 5056 21 PHASE I TRIAL OF LOW DOSE DECITABINE TARGETING DNA HYPERMETHYLATION IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKAEMIA AND NON-HODGKIN LYMPHOMA: DOSE-LIMITING MYELOSUPPRESSION WITHOUT EVIDENCE OF DNA HYPOMETHYLATION. TARGETING ABERRANT DNA HYPERMETHYLATION IN CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) AND NON-HODGKIN LYMPHOMA (NHL) WITH DECITABINE MAY REVERSE EPIGENETIC SILENCING IN B-CELL MALIGNANCIES. TWENTY PATIENTS WERE ENROLLED IN TWO PHASE I TRIALS TO DETERMINE THE MINIMUM EFFECTIVE PHARMACOLOGICAL DOSE OF DECITABINE IN PATIENTS WITH RELAPSED/REFRACTORY CLL (N = 16) AND NHL (N = 4). PATIENTS RECEIVED 1-3 CYCLES OF DECITABINE. DOSE-LIMITING TOXICITY (DLT) WAS OBSERVED IN 2 OF 4 CLL AND 2 OF 2 NHL PATIENTS RECEIVING DECITABINE AT 15 MG/M(2) PER D DAYS 1-10, CONSISTING OF GRADE 3-4 THROMBOCYTOPENIA AND HYPERBILIRUBINAEMIA. SIX PATIENTS WITH CLL RECEIVED DECITABINE AT 10 MG/M(2) PER D DAYS 1-10 WITHOUT DLT; HOWEVER, RE-EXPRESSION OF METHYLATED GENES OR CHANGES IN GLOBAL DNA METHYLATION WERE NOT OBSERVED. THEREFORE, A 5-DAY DECITABINE SCHEDULE WAS EXAMINED. WITH 15 MG/M(2) PER D DECITABINE DAYS 1-5, DLT OCCURRED IN 2 OF 6 CLL AND 2 OF 2 NHL PATIENTS, CONSISTING OF GRADE 3-4 NEUTROPENIA, THROMBOCYTOPENIA, AND FEBRILE NEUTROPENIA. EIGHT PATIENTS HAD STABLE DISEASE. IN 17 PATIENTS, THERE WERE NO SIGNIFICANT CHANGES IN GENOME-WIDE METHYLATION OR IN TARGET GENE RE-EXPRESSION. IN CONCLUSION, DOSE-LIMITING MYELOSUPPRESSION AND INFECTIOUS COMPLICATIONS PREVENTED DOSE ESCALATION OF DECITABINE TO LEVELS ASSOCIATED WITH CHANGES IN GLOBAL METHYLATION OR GENE RE-EXPRESSION IN CLL AND NHL. 2010 20 1213 29 CPG ISLAND METHYLATION PATTERNS IN CHRONIC LYMPHOCYTIC LEUKEMIA. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON LEUKEMIA IN WESTERN COUNTRIES. IN CLL, A LARGE NUMBER OF GENES AFFECTING CANCER-RELATED PATHWAYS MAY BE DYSREGULATED BY EPIGENETIC SILENCING. WE ANALYSED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION THE CPG ISLAND METHYLATION STATUS OF 15 WELL-CHARACTERISED CANCER-RELATED GENES IN 32 PATIENTS WITH CLL. ABERRANT METHYLATION IN THE SAMPLE OF PATIENTS WITH CLL WAS SHOWN FOR SECRETED FRIZZLED-RELATED PROTEIN 1 (68.8%), SECRETED FRIZZLED-RELATED PROTEIN 2 (65.6%), DEATH-ASSOCIATED PROTEIN KINASE 1 (50.0%), E-CADHERIN (21.9%), SECRETED FRIZZLED-RELATED PROTEIN 4 (15.6%), P15 (9.4%), P16 (6.3%), RETINOIC ACID RECEPTOR BETA2 (3.1%), SECRETED FRIZZLED-RELATED PROTEIN 5 (3.1%) AND TISSUE INHIBITOR OF MATRIX METALLOPROTEINASES 3 (3.1%). FOR HUMAN MUT-L HOMOLOG 1, O(6)-METHYLGUANINE DNA METHYLTRANSFERASE, P73, SUPPRESSOR OF CYTOKINE SIGNALLING 1 AND TISSUE INHIBITOR OF MATRIX METALLOPROTEINASES 2 NO HYPERMETHYLATION WAS DETECTED. HYPERMETHYLATION OF AT LEAST ONE GENE WAS OBSERVED IN 87.5% OF THE SAMPLES. OUR RESULTS SHOW THAT ABERRANT CPG ISLAND METHYLATION AFFECTING CANCER-RELATED PATHWAYS SUCH AS WNT SIGNALLING, REGULATION OF APOPTOSIS, CELL CYCLE CONTROL AND TISSUE INVASION IS A COMMON PHENOMENON IN CLL. EPIGENETIC DISTURBANCES MAY BE INVOLVED IN THE PATHOGENESIS OF CLL AND THUS MAY PROVIDE A MOLECULAR RATIONALE FOR THERAPEUTIC APPROACHES. 2009