1 2135 182 EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IN SERUM OF PATIENTS WITH CUTANEOUS MELANOMA. SMALL AMOUNTS OF CELL-FREE DNA CIRCULATE IN BOTH HEALTHY AND DISEASED HUMAN BLOOD, WHILE INCREASED CONCENTRATIONS OF DNA ARE PRESENT IN THE SERUM OF CANCER PATIENTS. TUMOR-SPECIFIC MUTATIONS OR EPIGENETIC MODIFICATIONS HAVE PREDOMINANTLY BEEN DETECTED IN TISSUE SPECIMENS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE METHYLATION OF FIVE DIFFERENT GENES INVOLVED IN TUMOR SUPPRESSION AND DNA REPAIR (SUPPRESSORS OF CYTOKINE SIGNALING 1 AND 2 (SOCS1, SOCS2)), RAS-ASSOCIATION DOMAIN FAMILY PROTEIN 1A (RASSF1A), D-TYPE P16(INK4A) CYCLIN-DEPENDENT KINASE INHIBITOR (CDKN), AND O6-METHYLGUANINE DNA-METHYLTRANSFERASE (MGMT)) IN THE SERUM OF 100 PATIENTS USING METHYLATION-SPECIFIC PCR. IN ALL, 41 MELANOMA PATIENTS (STAGE I = 18; STAGE II = 10; STAGE III/IV = 13), 13 HEALTHY CONTROLS WITHOUT NEVI, AND 10 INDIVIDUALS WITH MORE THAN 15 NEVI OF >5 MM IN SIZE WERE INVESTIGATED. FOR COMPARISON, SERA FROM PATIENTS WITH OTHER SKIN TUMORS (NINE BASAL CELL CANCERS, FIVE KAPOSI'S SARCOMA), DIFFERENT METASTASIZED CANCERS (FIVE BREAST CANCERS, FIVE COLON CANCERS), AND SEVERAL CHRONIC INFLAMMATORY DISEASES (N = 12) WERE ALSO ANALYZED. IN ADDITION, WE EXAMINED IF METHYLATION WAS INVOLVED IN SILENCING TRANSCRIPTION OF THESE GENES IN 12 MELANOMA SPECIMENS. SOCS1, SOCS2, RASSF1A, CDKN2A, AND MGMT WERE METHYLATED IN 75, 43, 64, 75, AND 64% OF MELANOMA SAMPLES, RESPECTIVELY. OF THE 41 MELANOMA PATIENTS, 83% HAD ONE HYPERMETHYLATED GENE, WHILE 66, 51, AND 41% HAD TWO, THREE, OR FOUR HYPERMETHYLATED GENES, RESPECTIVELY. ALSO, 20% OF THESE PATIENTS SHOWED HYPERMETHYLATION FOR ALL GENES, WHILE ONLY 17% SHOWED NO METHYLATION. IMPORTANTLY, THE METHYLATION PROFILE OF THE SELECTED GENES FROM MELANOMA PATIENTS WAS DISTINCT FROM THE OTHER ANALYZED TUMORS. TRANSCRIPTION OF SOCS1, SOCS2, CDKN2A, AND RASSF1A GENES WAS SIGNIFICANTLY REDUCED IN FRESH MELANOMA SAMPLES, WHILE MGMT SHOWED A 12-FOLD UPREGULATION AT THE MESSENGER RIBONUCLEIC ACID LEVEL (P < 0.001). OUR FINDINGS SUGGEST THAT EPIGENETIC SILENCING OF THE STUDIED TUMOR SUPPRESSOR GENES IS A COMMON AND PROBABLY IMPORTANT MECHANISM FOR MELANOMA FORMATION. THIS CONVENIENT METHOD USING A SIMPLE BLOOD SAMPLE MAY CONTRIBUTE TO CLASSIFICATION OF MELANOMA AND AWAITS CLINICAL VALIDATION. 2006 2 5617 38 SARCOSINE SUPPRESSES EPILEPTOGENESIS IN RATS WITH EFFECTS ON HIPPOCAMPAL DNA METHYLATION. EPILEPTOGENESIS IS A COMMON CONSEQUENCE OF BRAIN INSULTS, HOWEVER, THE PREVENTION OR DELAY OF THE EPILEPTOGENIC PROCESS REMAINS AN IMPORTANT UNMET MEDICAL CHALLENGE. OVEREXPRESSION OF GLYCINE TRANSPORTER 1 (GLYT1) IS PROPOSED AS A PATHOLOGICAL HALLMARK IN THE HIPPOCAMPUS OF PATIENTS WITH TEMPORAL LOBE EPILEPSY (TLE), AND WE PREVIOUSLY DEMONSTRATED IN RODENT EPILEPSY MODELS THAT AUGMENTATION OF GLYCINE SUPPRESSED CHRONIC SEIZURES AND ALTERED ACUTE SEIZURE THRESHOLDS. IN THE PRESENT STUDY WE EVALUATED THE EFFECT OF THE GLYT1 INHIBITOR, SARCOSINE (AKA N-METHYLGLYCINE), ON EPILEPTOGENESIS AND ALSO INVESTIGATED POSSIBLE MECHANISMS. WE DEVELOPED A MODIFIED RAPID KINDLING MODEL OF EPILEPTOGENESIS IN RATS COMBINED WITH SEIZURE SCORE MONITORING TO EVALUATE THE ANTIEPILEPTOGENIC EFFECT OF SARCOSINE. WE USED IMMUNOHISTOCHEMISTRY AND WESTERN BLOT ANALYSIS FOR THE EVALUATION OF GLYT1 EXPRESSION AND EPIGENETIC CHANGES OF 5-METHYLCYTOSINE (5MC) AND 5-HYDROXYMETHYLCYTOSINE (5HMC) IN THE EPILEPTOGENIC HIPPOCAMPI OF RATS, AND FURTHER EVALUATED EXPRESSION CHANGES IN ENZYMES INVOLVED IN THE REGULATION OF DNA METHYLATION, TEN-ELEVEN TRANSLOCATION METHYLCYTOSINE DIOXYGENASE 1 (TET1), DNA-METHYLTRANSFERASE 1 (DNMT1), AND DNMT3A. OUR RESULTS DEMONSTRATED: (I) EXPERIMENTAL EVIDENCE THAT SARCOSINE (3 G/KG, I.P. DAILY) SUPPRESSED KINDLING EPILEPTOGENESIS IN RATS; (II) THE SARCOSINE-INDUCED ANTIEPILEPTOGENIC EFFECT WAS ACCOMPANIED BY A SUPPRESSED HIPPOCAMPAL GLYT1 EXPRESSION AS WELL AS A REDUCTION OF HIPPOCAMPAL 5MC LEVELS AND A CORRESPONDING INCREASE IN 5HMC; AND (III) SARCOSINE TREATMENT CAUSED DIFFERENTIAL EXPRESSION CHANGES OF TET1 AND DNMTS. TOGETHER, THESE FINDINGS SUGGEST THAT SARCOSINE HAS UNPRECEDENTED DISEASE-MODIFYING PROPERTIES IN A KINDLING MODEL OF EPILEPTOGENESIS IN RATS, WHICH WAS ASSOCIATED WITH ALTERED HIPPOCAMPAL DNA METHYLATION. THUS, MANIPULATION OF THE GLYCINE SYSTEM IS A POTENTIAL THERAPEUTIC APPROACH TO ATTENUATE THE DEVELOPMENT OF EPILEPSY. 2020 3 740 37 CANCER/TESTIS ANTIGENS: EXPRESSION, REGULATION, TUMOR INVASION, AND USE IN IMMUNOTHERAPY OF CANCERS. CANCER/TESTIS ANTIGENS (CTAS) ARE NAMED BASED ON THEIR EXPRESSION PATTERN THAT IS RESTRICTED IN A NUMBER OF NORMAL AND ABNORMAL TISSUES. TUMOR CELLS FREQUENTLY EXPRESS ANTIGENS WHOSE EXPRESSION IS TYPICALLY RESTRICTED TO GERM CELLS. THEIR UNIQUE EXPRESSION PATTERN IS GUARANTEED BY PRECISE EPIGENETIC REGULATORY MECHANISMS. BECAUSE OF THEIR TUMOR-LIMITED, HIGH IMMUNOGENICITY, AND BIASED EXPRESSION, DISCOVERY OF THESE MOLECULES PROVIDES UNPRECEDENTED OPPORTUNITIES FOR FURTHER RESEARCH AND CLINICAL DEVELOPMENT IN THE FIELD OF CANCER DIAGNOSIS AND IMMUNOTHERAPY. EVOLVING EVIDENCE REVEALS THAT A NUMBER OF CTAS STIMULATE EPITHELIAL MESENCHYMAL TRANSITION (EMT) AND GENERATION OF CANCER STEM-LIKE CELLS, INTENSIFYING METASTASIS, INVASION, AND TUMORIGENESIS. BASED ON THESE FEATURES, CTAS ATTRACT ATTENTION TO BE CONSIDERED AS IDEAL TARGETS FOR DEVELOPING SEVERAL CLINICAL TRIALS, MANY OF THEM CONCENTRATING ON CTA VACCINE THERAPY. ACCORDING TO RECENT PRACTICAL CLINICAL INTEREST, MORE CHARACTERIZATIONS OF CTA REGULATION ARE IDENTIFIED. CTA EXPRESSION HAS BEEN DEMONSTRATED IN A VARIETY OF HUMAN CANCER TISSUES, AND SOME OF THEM HAVE BEEN FOUND TO ELICIT HUMORAL AND/OR CELLULAR IMMUNE RESPONSES IN CANCER PATIENTS. CTAS ARE BRILLIANT TARGETS FOR ANTICANCER DRUG DISCOVERY, TARGETED TUMOR THERAPY, AND DIAGNOSTIC BIOMARKERS, FURTHERMORE, VALUED GENES IN THE STUDY OF IMMUNOTHERAPY, PROMOTING TUMORIGENESIS, AND MALIGNANT PROGRESSION. THIS REVIEW OUTLINES AND CATEGORIZES OUR CURRENT UNDERSTANDING OF THE COMPLEX AND BIASED PROCESS OF CTAS MRNA AND PROTEIN EXPRESSION IN CANCER, AND SUPPLIES THE MOST RECENT INFORMATION ON THEIR REGULATION AND FUNCTION. BESIDES, A CONCISE SYNOPSIS OF THE MAJOR CLINICAL TRIALS INVOLVING CTAS, AS THERAPEUTIC AVENUES, IS DISCUSSED. ABBREVIATIONS: AIRE: AUTOIMMUNE REGULATOR; CAMP: CYCLIC ADENOSINE 3',5'-CYCLIC MONOPHOSPHATE; CEA: CARCINOEMBRYONIC ANTIGEN; CML: CHRONIC MYELOID LEUKEMIA; CREB: CYCLICAMP RESPONSE ELEMENT BINDING; CSCS: CANCER STEM CELLS; CTAS: CANCER/TESTIS ANTIGENS; CTL: CYTOTOXIC T LYMPHOCYTE; DCS: DENDRITIC CELLS; EMT: EPITHELIAL-MESENCHYMAL TRANSITION; ERK: EXTRACELLULAR SIGNAL-REGULATED KINASE; ESCC: ESOPHAGEAL SQUAMOUS CELL CARCINOMA; ETS: E26 TRANSFORMATION-SPECIFIC; HIS: HISTIDINE; HLA: HUMAN LEUKOCYTE ANTIGEN; HNSCC: HEAD AND NECK SQUAMOUS CELL CARCINOMA; IFN-GAMMA: INTERFERON-GAMMA; IHC: IMMUNOHISTOCHEMISTRY; IL-7: INTERLEUKIN7; MHC: MAJOR HISTOCOMPATIBILITY COMPLEX; MMP2: MATRIX METALLOPROTEINASE 2; MTECS: MEDULLARY THYMUS EPITHELIAL CELLS; MUC1: MUCIN 1; NSCLC: NON-SMALL CELL LUNG CANCER; PRAME: PREFERENTIALLY EXPRESSED ANTIGEN IN MELANOMA; RDA: REPRESENTATIONAL DIFFERENCE ANALYSIS; SEREX: SEROLOGICAL ANALYSIS OF CDNA EXPRESSION; SSX: SYNOVIAL SARCOMA X CHROMOSOME; TAAS: TUMOR-ASSOCIATED ANTIGENS; TCR: T-CELL RECEPTOR; TCGA: THE CANCER GENOME ATLAS; TGF-BETA: TRANSFORMING GROWTH FACTOR-BETA. 2016 4 6415 41 THE STUDY OF P16 AND P15 GENE METHYLATION IN HEAD AND NECK SQUAMOUS CELL CARCINOMA AND THEIR QUANTITATIVE EVALUATION IN PLASMA BY REAL-TIME PCR. EPIGENETIC SILENCING OF THE P16 AND P15 GENES BY PROMOTER METHYLATION ARE COMMONLY OBSERVED IN HUMAN EPITHELIAL MALIGNANCIES, INCLUDING HEAD AND NECK SQUAMOUS CELL CARCINOMAS (HNSCC). IN THIS STUDY, A METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) WAS USED TO EVALUATE THE METHYLATION STATUS OF THE P16 AND P15 GENES IN 73 HNSCC SURGICAL SPECIMENS. P16 AND P15 GENE METHYLATION WAS ALSO EXAMINED IN 29 PAIRED METASTATIC LYMPH NODES AND 29 PAIRED HISTOLOGICALLY, NORMAL RESECTION MARGIN MUCOSAE. THE QUANTITY OF CELL-FREE METHYLATED P16 AND P15 DNA IN THE PLASMA SAMPLES OF 20 HNSCC PATIENTS AND 24 HEALTHY CONTROLS WAS ALSO EXAMINED USING A FLUORESCENCE-BASED REAL-TIME PCR ASSAY. THE FREQUENCIES OF P16 AND P15 METHYLATION IN THE PRIMARY TUMOUR WERE 49% AND 60%, RESPECTIVELY. CONCORDANT METHYLATION OF P16 AND P15 IN TUMOUR SAMPLES AND METASTATIC LYMPH NODES WAS FOUND IN 59 AND 38% OF CASES, RESPECTIVELY. A SIGNIFICANTLY HIGHER PREVALENCE OF P15 METHYLATION WAS FOUND IN HISTOLOGICALLY-NORMAL SURGICAL MARGIN EPITHELIA OF HNSCC PATIENTS WITH CHRONIC SMOKING AND DRINKING HABITS COMPARED WITH NON-SMOKERS AND NON-DRINKERS. IN ADDITION, METHYLATED P16 AND P15 DNA LEVELS WERE SIGNIFICANTLY HIGHER IN THE PLASMA OF HNSCC PATIENTS (MEAN 56 COPIES/ML PLASMA AND 65 COPIES/ML PLASMA, RESPECTIVELY) COMPARED WITH NORMAL CONTROLS (MEAN 6 COPIES/ML PLASMA AND 16 COPIES/ML PLASMA, RESPECTIVELY). IN CONCLUSION, PROMOTER METHYLATION OF THE P16 AND P15 GENES IS INVOLVED IN THE PATHOGENESIS OF HNSCC AND MAY BE RELATED TO CHRONIC SMOKING AND DRINKING. THE DIFFERENTIAL LEVELS OF METHYLATED P16 AND P15 DNA IN PLASMA MIGHT BE POTENTIAL USEFUL MARKERS IN SCREENING HIGH-RISK POPULATIONS FOR EARLY HNSCC AND MONITORING THEIR TREATMENT RESPONSE. 2003 5 2326 37 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 6 150 44 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 7 4123 34 MECHANISMS OF DIMETHYLBENZANTHRACENE-INDUCED IMMUNOTOXICITY. TRADITIONAL METHODS FOR TOXICOLOGICAL ASSESSMENT HAVE IMPLICATED THE IMMUNE SYSTEM AS A FREQUENT TARGET ORGAN OF TOXIC INSULT FOLLOWING CHRONIC EXPOSURE TO CERTAIN ENVIRONMENTAL CHEMICALS, RADIATION OR THERAPEUTIC DRUGS (XENOBIOTICS). IMMUNOTOXICITY IS EXPRESSED AS AUTOIMMUNITY, CHEMICAL HYPERSENSITIVITY OR IMMUNOSUPPRESSION. A TIERED APPROACH FOR CHARACTERIZING CHEMICAL AND DRUG-INDUCED IMMUNOMODULATION HAS BEEN DEVELOPED AND VALIDATED IN LABORATORY ANIMALS. POLYCYCLIC AROMATIC HYDROCARBONS (PAH) HAVE BEEN STUDIED BECAUSE OF THEIR UBIQUITOUS PRESENCE IN THE ENVIRONMENT AND CARCINOGENIC POTENTIAL. SINCE IMMUNOSUPPRESSION INDUCED BY PAH CARCINOGENS HAS BEEN IMPLICATED AS AN EPIGENETIC MECHANISM IN THE OUTGROWTH OF INITIATED CELLS, THIS TIERED APPROACH WAS USED TO CHARACTERIZE THE MECHANISM OF PAH IMMUNOSUPPRESSIVE CAPACITY. PREVIOUSLY, STUDIES IN THIS LABORATORY HAVE DEMONSTRATED THAT SUBCHRONIC EXPOSURE OF B6C3F1 MICE TO PAH CARCINOGENS SUPPRESSES BOTH HUMORAL IMMUNITY (HI) AND CELL-MEDIATED IMMUNITY (CMI), CONCURRENTLY WITH DECREASED RESISTANCE TO TUMOR CHALLENGE. THE POTENT CARCINOGENIC PAH, 7,12-DIMETHYLBENZ[A]ANTHRACENE (DMBA) WAS SUBCHRONICALLY ADMINISTERED SUBCUTANEOUSLY AT 5, 50, OR 100 MICROGRAMS/G OF BODY WEIGHT. NATURAL KILLER (NK) CELL TUMOR CYTOLYSIS, GENERATION OF CYTOTOXIC T-CELLS (CTL), AND LYMPHOPROLIFERATION TO MITOGENS AND ALLOGENEIC SPLENOCYTES IN MIXED LEUKOCYTE CULTURES (MLC) WERE QUANTITATED 3-5 DAYS AFTER EXPOSURE TO ASSESS CMI. MITOGEN AND ALLOANTIGEN-INDUCED PROLIFERATION (MLC) OF SPLENOCYTES WAS SUPPRESSED UP TO 90%. CTL AND NK TUMOR CYTOLYSIS OF RADIOLABELLED TARGET CELLS WERE SIMILARLY DEPRESSED UP TO 88 AND 82%, RESPECTIVELY. IMPAIRMENT OF MLC OR CTL RESPONSES CORRELATED WITH INCREASED SUSCEPTIBILITY TO CHALLENGE WITH PYB6 SARCOMA CELLS. HI WAS MEASURED BY QUANTITATING THE NUMBER OF ANTIBODY (IGM) PLAQUE-FORMING CELLS (PFC) PRODUCED IN RESPONSE TO T-CELL DEPENDENT ANTIGEN CHALLENGE (SHEEP ERYTHROCYTES) AND WAS SIMILARLY SUPPRESSED UP TO 95%. TO UNDERSTAND THE MECHANISM OF PAH-INDUCED IMMUNOTOXICITY, SPLENOCYTES FROM DMBA-EXPOSED MICE WERE SENSITIZED TO ALLOANTIGENS IN THE PRESENCE OF INTERLEUKIN-2 (IL-2) BECAUSE THERE WERE INDICATIONS THAT T-HELPER CELL FUNCTION WAS SUPPRESSED. IN THESE PRELIMINARY STUDIES, CTL SUPPRESSION COULD BE COMPLETELY RESTORED BY THE ADDITION OF THE T-CELL GROWTH SUPPORTING LYMPHOKINE (IL-2) DURING THE INDUCTIVE PHASE OF CTL GENERATION, SUGGESTING THAT DMBA EXPOSURE DIRECTLY OR INDIRECTLY INDUCED DEFICITS IN T-HELPER CELL FUNCTION. 1985 8 2355 33 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 9 1495 39 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 10 1107 34 COMBINING CYTOGENETIC AND EPIGENETIC APPROACHES IN CHRONIC LYMPHOCYTIC LEUKEMIA IMPROVES PROGNOSIS PREDICTION FOR PATIENTS WITH ISOLATED 13Q DELETION. BACKGROUND: BOTH DEFECTIVE DNA METHYLATION AND ACTIVE DNA DEMETHYLATION PROCESSES ARE EMERGING AS IMPORTANT RISK FACTORS IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). HOWEVER, ASSOCIATIONS BETWEEN 5-CYTOSINE EPIGENETIC MARKERS AND THE MOST FREQUENT CHROMOSOMAL ABNORMALITIES DETECTED IN CLL REMAIN TO BE ESTABLISHED. METHODS: CLL PATIENTS WERE RETROSPECTIVELY CLASSIFIED INTO A CYTOGENETIC LOW-RISK GROUP (ISOLATED 13Q DELETION), AN INTERMEDIATE-RISK GROUP (NORMAL KARYOTYPE OR TRISOMY 12), AND A HIGH-RISK GROUP (11Q DELETION, 17P DELETION, OR COMPLEX KARYOTYPE [>/= 3 BREAKPOINTS]). THE TWO 5-CYTOSINE DERIVATIVES, 5-METHYLCYTOSINE (5-MCYT) AND 5-HYDROXYMETHYLCYTOSINE (5-HMCYT), WERE TESTED BY ELISA (N = 60), WHILE REAL-TIME QUANTITATIVE PCR WAS USED FOR DETERMINING TRANSCRIPTIONAL EXPRESSION LEVELS OF DNMT AND TET (N = 24). RESULTS: BY USING GLOBAL DNA METHYLATION/DEMETHYLATION LEVELS, IN THE LOW-RISK DISEASE GROUP, TWO SUBGROUPS WITH SIGNIFICANTLY DIFFERENT CLINICAL OUTCOMES HAVE BEEN IDENTIFIED (MEDIAN TREATMENT-FREE SURVIVAL [TFS] 45 VERSUS > 120 MONTHS FOR 5-MCYT, P = 0.0008, AND 63 VERSUS > 120 MONTHS FOR 5-HMCYT, P = 0.04). A DEFECTIVE 5-MCYT STATUS WAS FURTHER ASSOCIATED WITH A HIGHER PERCENTAGE OF 13Q DELETED NUCLEI (> 80%), THUS SUGGESTING AN ACQUIRED PROCESS. WHEN CONSIDERING THE CYTOGENETIC INTERMEDIATE/HIGH-RISK DISEASE GROUPS, AN ASSOCIATION OF 5-MCYT STATUS WITH LYMPHOCYTOSIS (P = 0.0008) AND THE LYMPHOCYTE DOUBLING TIME (P = 0.04) BUT NOT WITH TFS WAS OBSERVED, AS WELL AS A REDUCTION OF DNMT3A, TET1, AND TET2 TRANSCRIPTS. CONCLUSIONS: COMBINING CYTOGENETIC STUDIES WITH 5-MCYT ASSESSMENT ADDS ACCURACY TO CLL PATIENTS' PROGNOSES AND PARTICULARLY FOR THOSE WITH 13Q DELETION AS A SOLE CYTOGENETIC ABNORMALITY. 2017 11 5274 28 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 12 729 35 CANCER ANGIOGENESIS INDUCED BY KAPOSI SARCOMA-ASSOCIATED HERPESVIRUS IS MEDIATED BY EZH2. EZH2 IS A COMPONENT OF THE EPIGENETIC REGULATOR PRC2 THAT SUPPRESSES GENE EXPRESSION. ELEVATED EXPRESSION OF EZH2 IS COMMON IN HUMAN CANCERS AND IS ASSOCIATED WITH TUMOR PROGRESSION AND POOR PROGNOSIS. IN THIS STUDY, WE SHOW THAT EZH2 ELEVATION IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS OF KAPOSI SARCOMA-ASSOCIATED HERPESVIRUS (KSHV), AN ONCOGENIC VIRUS THAT PROMOTES THE DEVELOPMENT OF KAPOSI SARCOMA AND OTHER MALIGNANCIES THAT OCCUR IN PATIENTS WITH CHRONIC HIV INFECTIONS. KSHV INDUCTION OF EZH2 EXPRESSION WAS ESSENTIAL FOR KSHV-INDUCED ANGIOGENESIS. HIGH EXPRESSION OF EZH2 WAS OBSERVED IN KAPOSI SARCOMA TUMORS. IN CELL CULTURE, LATENT KSHV INFECTION UPREGULATED THE EXPRESSION OF EZH2 IN HUMAN ENDOTHELIAL CELLS THROUGH THE EXPRESSION OF VFLIP AND LANA, TWO KSHV-LATENT GENES THAT ACTIVATE THE NF-KAPPAB PATHWAY. KSHV-MEDIATED UPREGULATION OF EZH2 WAS REQUIRED FOR THE INDUCTION OF EPHRIN-B2, AN ESSENTIAL PROANGIOGENIC FACTOR THAT DRIVES ENDOTHELIAL CELL TUBULE FORMATION. TAKEN TOGETHER, OUR FINDINGS INDICATE THAT KSHV REGULATES THE HOST EPIGENETIC MODIFIER EZH2 TO PROMOTE ANGIOGENESIS. 2012 13 3294 40 HIGH INCIDENCE OF MGMT AND RARBETA PROMOTER METHYLATION IN PRIMARY GLIOBLASTOMAS: ASSOCIATION WITH HISTOPATHOLOGICAL CHARACTERISTICS, INFLAMMATORY MEDIATORS AND CLINICAL OUTCOME. GLIOBLASTOMAS, THE MOST FREQUENT PRIMARY BRAIN TUMORS IN ADULTS, ARE CHARACTERIZED BY A HIGHLY AGGRESSIVE, INFLAMMATORY AND ANGIOGENIC PHENOTYPE. METHYLATION OF CPG ISLANDS IN CANCER-RELATED GENES MAY SERVE AS AN EPIGENETIC BIOMARKER FOR GLIOBLASTOMA DIAGNOSIS AND PROGNOSIS. THE AIM OF THIS STUDY WAS TO ANALYZE THE METHYLATION STATUS OF FOUR CRITICAL TUMOR-ASSOCIATED GENES (MGMT, RARBETA, RASSF1A, CDH13), AND INVESTIGATE POSSIBLE LINKS WITH INFLAMMATORY (INTERLEUKIN [IL]-6, IL-8) AND ANGIOGENIC MEDIATORS (VASCULAR ENDOTHELIAL GROWTH FACTOR [VEGF], CYCLOOXYGENASE [COX]-2) AND CLINICAL OUTCOME IN 23 GLIOMA SAMPLES (6 GRADE II ASTROCYTOMAS, 17 GRADE IV GLIOBLASTOMAS). RARBETA AND MGMT GENES WERE MORE FREQUENTLY METHYLATED IN 70.58% AND 58.8% OF GLIOBLASTOMAS, RESPECTIVELY. RASSF1A AND CDH13 DISPLAYED A SIMILAR METHYLATION FREQUENCY (23.52%) IN GLIOBLASTOMAS. NO GENE METHYLATION WAS OBSERVED IN GRADE II ASTROCYTOMAS. TUMOR GRADE CORRELATED POSITIVELY WITH MGMT AND RARBETA METHYLATION (P = 0.005 AND P = 0.019, RESPECTIVELY) AND THE EXTENT OF NECROSIS (P = 0.001 AND P = 0.003). INTERESTINGLY, THE MARKER OF CHRONIC INFLAMMATION, IL-6, WAS POSITIVELY ASSOCIATED WITH METHYLATION OF MGMT (P = 0.004), RARBETA (P = 0.002), AND RASSF1A (P = 0.0081) AS WELL AS THE TOTAL NUMBER OF METHYLATED GENES (P < 0.0001), INDICATING THE IMPORTANT ROLE OF IL-6 IN MAINTAINING PROMOTER METHYLATION OF THESE GENES. VEGF EXPRESSION CORRELATED POSITIVELY WITH MGMT AND RARBETA METHYLATION ALTHOUGH THESE RELATIONSHIPS WERE OF MARGINAL SIGNIFICANCE (P = 0.0679 AND P = 0.0757). KAPLAN-MEIER UNIVARIATE SURVIVAL ANALYSIS INDICATED AN UNFAVORABLE SURVIVAL PERIOD IN PATIENTS WITH MGMT METHYLATION COMPARED WITH THOSE WITHOUT METHYLATION (P = 0.0474). OUR STUDY HIGHLIGHTS THE IMPLICATION OF MGMT AND RARBETA METHYLATION IN THE AGGRESSIVE PHENOTYPE OF PRIMARY GLIOBLASTOMAS. THE ASSOCIATION OF MGMT METHYLATION WITH CLINICAL OUTCOME INDICATES ITS POTENTIAL PROGNOSTIC VALUE. 2010 14 2960 33 GENETIC AND EPIGENETIC MARKERS IN THE EVALUATION OF PANCREATIC MASSES. BACKGROUND: METHYLATION MARKERS HAVE SHOWN PROMISE IN THE EARLY DIAGNOSIS OF PANCREATIC CARCINOMA. THE AIM OF THIS STUDY WAS TO ASSESS THE DIAGNOSTIC UTILITY OF HYPERMETHYLATION STATUS OF CANDIDATE GENES IN COMBINATION WITH KRAS MUTATION DETECTION IN THE EVALUATION OF PANCREATIC MASSES. EXPERIMENTAL DESIGN: SIXTY-ONE FINE NEEDLE ASPIRATES OF PANCREATIC MASSES (43 PANCREATIC ADENOCARCINOMAS AND 18 CHRONIC PANCREATITIS) WERE STUDIED. METHYLATION STATUS OF HRH2, EN1, SPARC, CDH13 AND APC WERE ANALYSED USING MELTING CURVE ANALYSIS AFTER DNA BISULFITE TREATMENT. KRAS MUTATIONS WERE ALSO ANALYSED. RESULTS: THE METHYLATION PANEL HAD A SENSITIVITY OF 73% (27 OF 37, CI 95% 56 TO 86%) AND A SPECIFICITY OF 100% WHENEVER TWO OR MORE PROMOTERS WERE FOUND HYPERMETHYLATED. KRAS MUTATIONS SHOWED A SENSITIVITY OF 77% (33 OF 43, CI 95% 62 TO 88%) AND A SPECIFICITY OF 100%. BOTH MOLECULAR ANALYSES ADDED USEFUL INFORMATION TO CYTOLOGY BY INCREASING THE NUMBER OF INFORMATIVE CASES. WHEN GENETIC AND EPIGENETIC ANALYSES WERE COMBINED SENSITIVITY WAS 84% (36 OF 43 CI 95% 69 TO 93%) MAINTAINING A 100% SPECIFICITY. CONCLUSIONS: ANALYSIS OF HYPERMETHYLATION STATUS OF A PANEL OF GENES AND KRAS MUTATION DETECTION OFFER A SIMILAR DIAGNOSTIC YIELD IN THE EVALUATION OF PANCREATIC MASSES. THE COMBINED MOLECULAR ANALYSIS INCREASES THE NUMBER OF INFORMATIVE CASES WITHOUT DIMINISHING SPECIFICITY. 2013 15 2765 29 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 16 1213 43 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 17 2847 39 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 18 1968 37 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 4903 38 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 20 2132 36 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