1 1122 146 COMPARISON OF GENE EXPRESSION PROFILES IN CHROMATE TRANSFORMED BEAS-2B CELLS. BACKGROUND: HEXAVALENT CHROMIUM [CR(VI)] IS A POTENT HUMAN CARCINOGEN. OCCUPATIONAL EXPOSURE HAS BEEN ASSOCIATED WITH INCREASED RISK OF RESPIRATORY CANCER. MULTIPLE MECHANISMS HAVE BEEN SHOWN TO CONTRIBUTE TO CR(VI) INDUCED CARCINOGENESIS, INCLUDING DNA DAMAGE, GENOMIC INSTABILITY, AND EPIGENETIC MODULATION, HOWEVER, THE MOLECULAR MECHANISM AND DOWNSTREAM GENES MEDIATING CHROMIUM'S CARCINOGENICITY REMAIN TO BE ELUCIDATED. METHODS/RESULTS: WE ESTABLISHED CHROMATE TRANSFORMED CELL LINES BY CHRONIC EXPOSURE OF NORMAL HUMAN BRONCHIAL EPITHELIAL BEAS-2B CELLS TO LOW DOSES OF CR(VI) FOLLOWED BY ANCHORAGE-INDEPENDENT GROWTH. THESE TRANSFORMED CELL LINES NOT ONLY EXHIBITED CONSISTENT MORPHOLOGICAL CHANGES BUT ALSO ACQUIRED ALTERED AND DISTINCT GENE EXPRESSION PATTERNS COMPARED WITH NORMAL BEAS-2B CELLS AND CONTROL CELL LINES (UNTREATED) THAT AROSE SPONTANEOUSLY IN SOFT AGAR. INTERESTINGLY, THE GENE EXPRESSION PROFILES OF SIX CR(VI) TRANSFORMED CELL LINES WERE REMARKABLY SIMILAR TO EACH OTHER YET DIFFERED SIGNIFICANTLY FROM THAT OF EITHER CONTROL CELL LINES OR NORMAL BEAS-2B CELLS. A TOTAL OF 409 DIFFERENTIALLY EXPRESSED GENES WERE IDENTIFIED IN CR(VI) TRANSFORMED CELLS COMPARED TO CONTROL CELLS. GENES RELATED TO CELL-TO-CELL JUNCTION WERE UPREGULATED IN ALL CR(VI) TRANSFORMED CELLS, WHILE GENES ASSOCIATED WITH THE INTERACTION BETWEEN CELLS AND THEIR EXTRACELLULAR MATRICES WERE DOWN-REGULATED. ADDITIONALLY, EXPRESSION OF GENES INVOLVED IN CELL PROLIFERATION AND APOPTOSIS WERE ALSO CHANGED. CONCLUSION: THIS STUDY IS THE FIRST TO REPORT GENE EXPRESSION PROFILING OF CR(VI) TRANSFORMED CELLS. THE GENE EXPRESSION CHANGES ACROSS INDIVIDUAL CHROMATE EXPOSED CLONES WERE REMARKABLY SIMILAR TO EACH OTHER BUT DIFFERED SIGNIFICANTLY FROM THE GENE EXPRESSION FOUND IN ANCHORAGE-INDEPENDENT CLONES THAT AROSE SPONTANEOUSLY. OUR ANALYSIS IDENTIFIED MANY NOVEL GENE EXPRESSION CHANGES THAT MAY CONTRIBUTE TO CHROMATE INDUCED CELL TRANSFORMATION, AND COLLECTIVELY THIS TYPE OF INFORMATION WILL PROVIDE A BETTER UNDERSTANDING OF THE MECHANISM UNDERLYING CHROMATE CARCINOGENICITY. 2011 2 329 37 ALPHA-OXOGLUTARATE INHIBITS THE PROLIFERATION OF IMMORTALIZED NORMAL BLADDER EPITHELIAL CELLS VIA AN EPIGENETIC SWITCH INVOLVING ARID1A. INTERSTITIAL CYSTITIS (IC) IS A CHRONIC URINARY TRACT DISEASE THAT IS CHARACTERIZED BY UNPLEASANT SENSATIONS, SUCH AS PERSISTENT PELVIC PAIN, IN THE ABSENCE OF INFECTION OR OTHER IDENTIFIABLE CAUSES. WE PREVIOUSLY PERFORMED COMPREHENSIVE METABOLOMICS PROFILING OF URINE SAMPLES FROM IC PATIENTS USING NUCLEAR MAGNETIC RESONANCE AND GAS-CHROMATOGRAPHY/MASS SPECTROMETRY AND FOUND THAT URINARY ALPHA-OXOGLUTARATE (ALPHA-OG), WAS SIGNIFICANTLY ELEVATED. ALPHA-OG, A TRICARBOXYLIC ACID (TCA) CYCLE INTERMEDIATE, REPORTEDLY FUNCTIONS TO SUPPRESS THE PROLIFERATION OF IMMORTALIZED NORMAL HUMAN BLADDER EPITHELIAL CELLS. HERE, WE IDENTIFIED AT-RICH INTERACTIVE DOMAIN 1 A (ARID1A), A KEY CHROMATIN REMODELER, AS BEING HYPOMETHYLATED AND UPREGULATED BY ALPHA-OG TREATMENT. THIS WAS DONE THROUGH EPIC DNA METHYLATION PROFILING AND SUBSEQUENT BIOCHEMICAL APPROACHES, INCLUDING QUANTITATIVE RT-PCR AND WESTERN BLOT ANALYSES. FURTHERMORE, WE FOUND THAT ALPHA-OG ALMOST COMPLETELY SUPPRESSES TEN-ELEVEN TRANSLOCATION (TET) ACTIVITY, BUT DOES NOT AFFECT DNA METHYLTRANSFERASE (DNMT) ACTIVITY. ALTOGETHER, OUR STUDIES REVEAL THE POTENTIAL ROLE OF ALPHA-OG IN EPIGENETIC REMODELING THROUGH ITS EFFECTS ON ARID1A AND TET EXPRESSION IN THE BLADDER. THIS MAY PROVIDE A NEW POSSIBLE THERAPEUTIC STRATEGY IN TREATING IC. 2018 3 3983 41 LONG-TERM EXPOSURE TO CIGARETTE SMOKE EXTRACT INDUCES HYPOMETHYLATION AT THE RUNX3 AND IGF2-H19 LOCI IN IMMORTALIZED HUMAN UROTHELIAL CELLS. CIGARETTE SMOKING IS THE SINGLE MOST IMPORTANT EPIDEMIOLOGICAL RISK FACTOR FOR BLADDER CANCER BUT IT IS NOT KNOWN WHETHER EXPOSURE OF UROTHELIAL CELLS TO THE SYSTEMIC SOLUBLE CONTENTS OF CIGARETTE SMOKE IS DIRECTLY CAUSATIVE TO BLADDER CANCER AND THE ASSOCIATED EPIGENETIC CHANGES SUCH AS TUMOR SUPPRESSOR GENE HYPERMETHYLATION. WE UNDERTOOK THIS STUDY TO INVESTIGATE IF LONG-TERM TREATMENT OF HUMAN UROTHELIAL CELLS WITH CIGARETTE SMOKE EXTRACT (CSE) RESULTS IN TUMOR SUPPRESSOR GENE HYPERMETHYLATION, A PHENOTYPE THAT WAS PREVIOUSLY ASSOCIATED WITH LONG-TERM CONSTANT CSE TREATMENT OF AIRWAY EPITHELIAL CELLS. WE CHRONICALLY TREATED AN IMMORTALIZED HUMAN UROTHELIAL CELL LINE UROTSA WITH CSE USING A CYCLIC DAILY REGIMEN BUT THE CELLS WERE CULTURED IN CSE-FREE MEDIUM BETWEEN DAILY TREATMENTS. BISULFITE SEQUENCING AND REAL-TIME PCR ARRAY-BASED METHYLATION PROFILING WERE EMPLOYED TO EVALUATE METHYLATION CHANGES AT TUMOR SUPPRESSOR GENE LOCI IN THE CHRONICALLY CSE-TREATED CELLS VERSUS THE PASSAGE-MATCHED UNTREATED CONTROL CELLS. THE RUNX3 TUMOR SUPPRESSOR GENE PROMOTER WAS HYPOMETHYLATED WITH A SIGNIFICANT INCREASE IN PROPORTION OF THE COMPLETELY UNMETHYLATED HAPLOTYPE AFTER THE LONG-TERM CSE TREATMENT; WHEREAS RUNX3 PROMOTER HYPERMETHYLATION WAS PREVIOUSLY REPORTED FOR BLADDER CANCERS OF SMOKERS. HYPOMETHYLATION INDUCED BY THE LONG-TERM CSE TREATMENT WAS ALSO OBSERVED FOR THE IGF2-H19 LOCUS. THE METHYLATION STATUS AT THE PRSS8/PROSTASIN AND 16 ADDITIONAL LOCI HOWEVER, WAS UNAFFECTED BY THE CHRONIC CSE TREATMENT. TRANSIENT CSE TREATMENT OVER 1 DAILY REGIMEN RESULTED IN TRANSCRIPTIONAL DOWN-REGULATION OF RUNX3 AND H19, BUT ONLY THE H19 TRANSCRIPTION WAS DOWN-REGULATED IN THE CHRONICALLY CSE-TREATED UROTHELIAL CELLS. TRANSCRIPTION OF A KEY ENZYME IN ONE-CARBON METABOLISM, DIHYDROFOLATE REDUCTASE (DHFR) WAS GREATLY REDUCED BY THE LONG-TERM CSE TREATMENT, POTENTIALLY SERVING AS A MECHANISM FOR THE HYPOMETHYLATION PHENOTYPE VIA A REDUCED SUPPLY OF METHYL DONOR. IN CONCLUSION, CHRONIC CYCLIC CSE TREATMENT OF UROTHELIAL CELLS INDUCED HYPOMETHYLATION RATHER THAN HYPERMETHYLATION AT SPECIFIC LOCI. 2013 4 2326 35 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 5 1212 28 CPG ISLAND METHYLATION OF THE HTERT PROMOTER IS ASSOCIATED WITH LOWER TELOMERASE ACTIVITY IN B-CELL LYMPHOCYTIC LEUKEMIA. OBJECTIVE: EXPRESSION OF THE CATALYTIC SUBUNIT OF THE TELOMERASE ENZYME HTERT IS ESSENTIAL FOR PROLONGING THE REPLICATIVE LIFESPAN AND IS THE RATE-LIMITING STEP IN CELLULAR IMMORTALIZATION AND CARCINOGENESIS. BECAUSE HTERT EXPRESSION IS POSITIVELY CORRELATED WITH TELOMERASE ACTIVITY, ITS REGULATION IS SUGGESTED AS THE MAJOR DETERMINANT OF ENZYMATIC ACTIVITY. THE HTERT PROMOTER REGION CONTAINS TWO CPG ISLANDS, WHICH ARE KNOWN TO BE TARGET SITES FOR DE NOVO DNA METHYLATION. TO ELUCIDATE THE IMPACT OF THIS EPIGENETIC MECHANISM ON TELOMERASE ACTIVITY, WE ANALYZED THE DEGREE OF HTERT PROMOTER METHYLATION IN 30 PATIENTS WITH B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA. MATERIALS AND METHODS: HTERT PROMOTER METHYLATION WAS ASSESSED USING A METHYLATION-SPECIFIC COMPETITIVE POLYMERASE CHAIN REACTION ASSAY. THE ASSAY IS BASED ON DIGESTION OF GENOMIC DNA WITH A METHYLATION-SENSITIVE RESTRICTION ENZYME BEFORE AMPLIFICATION WITH AN INTERNAL STANDARD. RESULTS: PATIENTS EXHIBITING HIGH TELOMERASE ACTIVITY SHOWED SIGNIFICANTLY LESS METHYLATION OF THE HTERT PROMOTER CORE DOMAIN THAN PATIENTS WITH LOW ENZYME ACTIVITY. IN ADDITION, TELOMERASE ACTIVITY WAS SIGNIFICANTLY ASSOCIATED WITH TELOMERE LENGTH AND OVERALL SURVIVAL. CONCLUSIONS: OUR DATA SHOW THAT THE DEGREE OF CPG ISLAND METHYLATION OF THE HTERT PROMOTER EXHIBITS AN IMPACT ON TELOMERASE ACTIVITY IN A SUBGROUP OF PATIENTS WITH B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA AND THEREFORE IS ASSUMED TO PLAY A ROLE IN REGULATING HTERT GENE EXPRESSION IN THESE PATIENTS. 2002 6 3780 36 INTERFERON DRIVES HCV SCARRING OF THE EPIGENOME AND CREATES TARGETABLE VULNERABILITIES FOLLOWING VIRAL CLEARANCE. BACKGROUND AND AIMS: CHRONIC HCV INFECTION IS A LEADING ETIOLOGIC DRIVER OF CIRRHOSIS AND ULTIMATELY HCC. OF THE APPROXIMATELY 71 MILLION INDIVIDUALS CHRONICALLY INFECTED WITH HCV, 10%-20% ARE EXPECTED TO DEVELOP SEVERE LIVER COMPLICATIONS IN THEIR LIFETIME. EPIGENETIC MECHANISMS INCLUDING DNA METHYLATION AND HISTONE MODIFICATIONS BECOME PROFOUNDLY DISRUPTED IN DISEASE PROCESSES INCLUDING LIVER DISEASE. APPROACH AND RESULTS: TO UNDERSTAND HOW HCV INFECTION INFLUENCES THE EPIGENOME AND WHETHER THESE EVENTS REMAIN AS "SCARS" FOLLOWING CURE OF CHRONIC HCV INFECTION, WE MAPPED GENOME-WIDE DNA METHYLATION, FOUR KEY REGULATORY HISTONE MODIFICATIONS (H3K4ME3, H3K4ME1, H3K27AC, AND H3K27ME3), AND OPEN CHROMATIN IN PARENTAL AND HCV-INFECTED IMMORTALIZED HEPATOCYTES AND THE HUH7.5 HCC CELL LINE, ALONG WITH DNA METHYLATION AND GENE-EXPRESSION ANALYSES FOLLOWING ELIMINATION OF HCV IN THESE MODELS THROUGH TREATMENT WITH INTERFERON-ALPHA (IFN-ALPHA) OR A DIRECT-ACTING ANTIVIRAL (DAA). OUR DATA DEMONSTRATE THAT HCV INFECTION PROFOUNDLY AFFECTS THE EPIGENOME (PARTICULARLY ENHANCERS); HCV SHARES EPIGENETIC TARGETS WITH INTERFERON-ALPHA TARGETS; AND AN OVERWHELMING MAJORITY OF EPIGENETIC CHANGES INDUCED BY HCV REMAIN AS "SCARS" ON THE EPIGENOME FOLLOWING VIRAL CURE. SIMILAR FINDINGS ARE OBSERVED IN PRIMARY HUMAN PATIENT SAMPLES CURED OF CHRONIC HCV INFECTION. SUPPLEMENTATION OF IFN-ALPHA/DAA ANTIVIRAL REGIMENS WITH DNA METHYLTRANSFERASE INHIBITOR 5-AZA-2'-DEOXYCYTIDINE SYNERGIZES IN REVERTING ABERRANT DNA METHYLATION INDUCED BY HCV. FINALLY, BOTH HCV-INFECTED AND CURED CELLS DISPLAYED A BLUNTED IMMUNE RESPONSE, DEMONSTRATING A FUNCTIONAL EFFECT OF EPIGENETIC SCARRING. CONCLUSIONS: INTEGRATION OF EPIGENETIC AND TRANSCRIPTIONAL DATA ELUCIDATE KEY GENE DEREGULATION EVENTS DRIVEN BY HCV INFECTION AND HOW THIS MAY UNDERPIN THE LONG-TERM ELEVATED RISK FOR HCC IN PATIENTS CURED OF HCV DUE TO EPIGENOME SCARRING. 2022 7 4769 36 NUCLEAR MORPHOMETRY, NUCLEOMICS AND PROSTATE CANCER PROGRESSION. PROSTATE CANCER (PCA) RESULTS FROM A MULTISTEP PROCESS. THIS PROCESS INCLUDES INITIATION, WHICH OCCURS THROUGH VARIOUS AGING EVENTS AND MULTIPLE INSULTS (SUCH AS CHRONIC INFECTION, INFLAMMATION AND GENETIC INSTABILITY THROUGH REACTIVE OXYGEN SPECIES CAUSING DNA DOUBLE-STRAND BREAKS), FOLLOWED BY A MULTISTEP PROCESS OF PROGRESSION. THESE STEPS INCLUDE SEVERAL GENETIC AND EPIGENETIC ALTERATIONS, AS WELL AS ALTERATIONS TO THE CHROMATIN STRUCTURE, WHICH OCCUR IN RESPONSE TO THE CARCINOGENIC STRESS-RELATED EVENTS THAT SUSTAIN PROLIFERATIVE SIGNALING. EVENTS SUCH AS EVADING GROWTH SUPPRESSORS, RESISTING CELL DEATH, ENABLING REPLICATIVE IMMORTALITY, INDUCING ANGIOGENESIS, AND ACTIVATING INVASION AND METASTASIS ARE READILY OBSERVED. IN ADDITION, IN CONJUNCTION WITH THESE CRITICAL DRIVERS OF CARCINOGENESIS, OTHER FACTORS RELATED TO THE ETIOPATHOGENESIS OF PCA, INVOLVING ENERGY METABOLISM AND EVASION OF THE IMMUNE SURVEILLANCE SYSTEM, APPEAR TO BE INVOLVED. IN ADDITION, WHEN CANCER SPREAD AND METASTASIS OCCUR, THE 'TUMOR MICROENVIRONMENT' IN THE BONE OF PCA PATIENTS MAY PROVIDE A WAY TO SUSTAIN DORMANCY OR SENESCENCE AND EVENTUALLY ESTABLISH A 'SEED AND SOIL' SITE WHERE PCA PROLIFERATION AND GROWTH MAY OCCUR OVER TIME. WHEN PCA IS INITIATED AND PROGRESSION ENSUES, SIGNIFICANT ALTERATIONS IN NUCLEAR SIZE, SHAPE AND HETEROCHROMATIN (DNA TRANSCRIPTION) ORGANIZATION ARE FOUND, AND KEY NUCLEAR TRANSCRIPTIONAL AND STRUCTURAL PROTEINS, AS WELL AS MULTIPLE NUCLEAR BODIES CAN LEAD TO PRECANCEROUS AND MALIGNANT CHANGES. THESE SERIES OF CELLULAR AND TISSUE-RELATED MALIGNANCY-ASSOCIATED EVENTS CAN BE QUANTIFIED TO ASSESS DISEASE PROGRESSION AND MANAGEMENT. 2012 8 5116 23 POSITIVE REGULATION OF HUMAN TELOMERASE REVERSE TRANSCRIPTASE GENE EXPRESSION AND TELOMERASE ACTIVITY BY DNA METHYLATION IN PANCREATIC CANCER. AIM: WE SOUGHT TO DETERMINE THE ROLE OF TELOMERASE AND ITS CATALYTIC SUBUNIT HTERT IN PANCREATIC CANCER AND EVALUATE THE EPIGENETIC REGULATION OF HTERT BY PROMOTER METHYLATION. METHODS: THIRTY PAIRED SAMPLES OF PANCREATIC DUCTAL ADENOCARCINOMAS AND ADJACENT NORMAL TISSUE AND 12 CHRONIC PANCREATITIS SAMPLES WERE STUDIED. REVERSE TRANSCRIPTASE POLYMERASE CHAIN REACTION, TELOMERIC REPEAT AMPLIFICATION PROTOCOL ASSAY, AND METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION WERE PERFORMED TO ANALYZE HTERT EXPRESSION, TELOMERASE ACTIVITY, AND METHYLATION STATUS OF GENE PROMOTERS, RESPECTIVELY. RESULT: HTERT AND TELOMERASE ACTIVITY WERE UPREGULATED IN PANCREATIC CANCER COMPARED WITH PAIRED NORMAL TISSUES AND SAMPLES OF PANCREATITIS. HTERT EXPRESSION CORRELATED WITH TELOMERASE ACTIVITY (P \ .05) AND IN TURN CORRELATED POSITIVELY WITH HTERT PROMOTER METHYLATION (P \ .001) AND P16 PROMOTER METHYLATION. HTERT TRANSCRIPT EXPRESSION AND TELOMERASE ACTIVITY BOTH CONFERRED A WORSE OUTCOME BY UNIVARIATE AND MULTIVARIATE ANALYSIS (P \ .05). CONCLUSION: HTERT EXPRESSION AND TELOMERASE ACTIVITY ARE PREDICTORS OF POOR OUTCOME IN PANCREATIC CANCER. HTERT GENE EXPRESSION IS POSITIVELY REGULATED BY PROMOTER METHYLATION. 2009 9 1826 43 EFFECTS OF HISTONE DEACETYLASE INHIBITOR ON EXTRACELLULAR MATRIX PRODUCTION IN HUMAN NASAL POLYP ORGAN CULTURES. BACKGROUND: NASAL POLYPOSIS IS ASSOCIATED WITH A CHRONIC INFLAMMATORY CONDITION OF THE SINONASAL MUCOSA AND INVOLVES MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION. EPIGENETIC MODULATION BY HISTONE DEACETYLASE (HDAC) INHIBITORS INCLUDING TRICHOSTATIN A (TSA) HAS BEEN REPORTED TO HAVE INHIBITORY EFFECTS ON MYOFIBROBLAST DIFFERENTIATION IN LUNG AND RENAL FIBROBLASTS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE THE INHIBITORY EFFECT OF TSA ON MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION IN NASAL POLYP ORGAN CULTURES. METHODS: NASAL POLYP TISSUES FROM 18 PATIENTS WERE ACQUIRED DURING ENDOSCOPIC SINUS SURGERY. AFTER ORGAN CULTURE, NASAL POLYPS WERE STIMULATED WITH TGF-BETA1 AND THEN TREATED WITH TSA. ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), FIBRONECTIN, AND COLLAGEN TYPE I EXPRESSION LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION (PCR), REAL-TIME PCR, WESTERN BLOT, AND IMMUNOFLUORESCENT STAINING. HDAC2, HDAC4, AND ACETYLATED H4 EXPRESSION LEVELS WERE ASSAYED BY WESTERN BLOT. CYTOTOXICITY WAS ANALYZED BY THE TERMINAL DEOXYNUCLEOTIDYL TRANSFERASE BIOTIN-DUTP NICK END LABELING ASSAY. RESULTS: THE EXPRESSION LEVELS OF ALPHA-SMA, FIBRONECTIN, AND COLLAGEN TYPE 1 WERE INCREASED IN NASAL POLYP AFTER TRANSFORMING GROWTH FACTOR (TGF) BETA1 TREATMENT. TSA-INHIBITED TGF-BETA1 INDUCED THESE GENE AND PROTEIN EXPRESSION LEVELS. FURTHERMORE, TSA SUPPRESSED PROTEIN EXPRESSION LEVELS OF HDAC2 AND HDAC4. HOWEVER, TSA INDUCED HYPERACETYLATION OF HISTONES H4. TREATMENT WITH TGF-BETA1 WITH OR WITHOUT TSA DID NOT HAVE CYTOTOXIC EFFECT. CONCLUSION: THESE FINDINGS PROVIDE NOVEL INSIGHTS INTO THE EPIGENETIC REGULATION IN MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION OF NASAL POLYP. TSA COULD BE A CANDIDATE OF A THERAPEUTIC AGENT FOR REVERSING THE TGF-BETA1-INDUCED ECM SYNTHESIS THAT LEADS TO NASAL POLYP DEVELOPMENT. 2013 10 5057 27 PHENOBARBITAL MECHANISTIC DATA AND RISK ASSESSMENT: ENZYME INDUCTION, ENHANCED CELL PROLIFERATION, AND TUMOR PROMOTION. CHRONIC EXPOSURE TO HIGH DOSES OF PHENOBARBITAL (PB) CAUSES HEPATOCELLULAR ADENOMAS IN BOTH MICE AND RATS AND HEPATOCELLULAR CARCINOMAS IN SOME STRAINS OF MICE. LONG-TERM PB THERAPY HAS NOT BEEN FOUND TO CAUSE HUMAN TUMORS. PB IS NOT DNA REACTIVE, AND MOST GENOTOXICITY TESTS HAVE YIELDED NEGATIVE RESULTS. PB HAS BEEN EXTENSIVELY STUDIED AS AN EPIGENETIC, RODENT LIVER TUMOR PROMOTER. AT EXPOSURES CAUSING RODENT LIVER TUMORS, PB HAS MEASURABLE EFFECTS ON HEPATOCYTES: PB INHIBITS CELL-TO-CELL COMMUNICATION; PB INDUCES ENZYMES, INCLUDING P450 CYTOCHROMES; PB STIMULATES PROLIFERATION AND INHIBITS APOPTOSIS OF HEPATOCYTES IN NEOPLASTIC FOCI. THRESHOLD EXPOSURES FOR SOME OF THESE ENDPOINTS COINCIDE WITH THE THRESHOLD EXPOSURE FOR TUMORIGENESIS. 1996 11 3289 35 HIF-1ALPHA MEDIATES TUMOR HYPOXIA TO CONFER A PERPETUAL MESENCHYMAL PHENOTYPE FOR MALIGNANT PROGRESSION. ALTHOUGH TUMOR PROGRESSION INVOLVES GENETIC AND EPIGENETIC ALTERATIONS TO NORMAL CELLULAR BIOLOGY, THE UNDERLYING MECHANISMS OF THESE CHANGES REMAIN OBSCURE. NUMEROUS STUDIES HAVE SHOWN THAT HYPOXIA-INDUCIBLE FACTOR 1ALPHA (HIF-1ALPHA) IS OVEREXPRESSED IN MANY HUMAN CANCERS AND UP-REGULATES A HOST OF HYPOXIA-RESPONSIVE GENES FOR CANCER GROWTH AND SURVIVAL. WE RECENTLY IDENTIFIED AN ALTERNATIVE MECHANISM OF HIF-1ALPHA FUNCTION THAT INDUCES GENETIC ALTERATIONS BY SUPPRESSING DNA REPAIR. HERE, WE SHOW THAT LONG-TERM HYPOXIA, WHICH MIMICS THE TUMOR MICROENVIRONMENT, DRIVES A PERPETUAL EPITHELIAL-MESENCHYMAL TRANSITION (EMT) THROUGH UP-REGULATION OF THE ZINC FINGER E-BOX BINDING HOMEOBOX PROTEIN ZEB2, WHEREAS SHORT-TERM HYPOXIA INDUCES A REVERSIBLE EMT THAT REQUIRES THE TRANSCRIPTION FACTOR TWIST1. MOREOVER, WE SHOW THAT THE PERPETUAL EMT DRIVEN BY CHRONIC HYPOXIA DEPENDS ON HIF-1ALPHA INDUCTION OF GENETIC ALTERATIONS RATHER THAN ITS CANONICAL TRANSCRIPTIONAL ACTIVATOR FUNCTION. THESE MESENCHYMAL TUMOR CELLS NOT ONLY ACQUIRE TUMORIGENICITY BUT ALSO DISPLAY CHARACTERISTICS OF ADVANCED CANCERS, INCLUDING NECROSIS, AGGRESSIVE INVASION, AND METASTASIS. HENCE, THESE RESULTS REVEAL A MECHANISM BY WHICH HIF-1ALPHA PROMOTES A PERPETUAL MESENCHYMAL PHENOTYPE, THEREBY ADVANCING TUMOR PROGRESSION. 2011 12 3934 45 LIVER TUMOR INDUCTION. THE SIGNIFICANCE OF THE DEVELOPMENT OF NODULAR LIVER LESIONS IN RODENTS FOLLOWING THE ADMINISTRATION OF TEST AGENTS RAISES SEVERAL QUESTIONS WHICH COULD BE PLACED IN ONE OF TWO GENERAL CATEGORIES: DIAGNOSTIC AND INTERPRETATIONAL. FROM A DIAGNOSTIC POINT OF VIEW, THE PROPER CLASSIFICATION OF LIVER TUMORS INTO A BENIGN AND MALIGNANT CATEGORY HAS TO BE BASED ON THE DIRECT CORRELATION BETWEEN THE MORPHOLOGY AND THE BIOLOGIC BEHAVIOR OF THE LESIONS. THEREFORE, EXTREME CARE SHOULD BE TAKEN TO SEPARATE THE MALIGNANT TUMORS FROM THE BENIGN AND THE BENIGN NEOPLASIA FROM THE HYPERPLASIA. THE SUBSTITUTION OF THE TERM "NEOPLASTIC NODULE" FOR HYPERPLASTIC NODULE IN RATS IS MISLEADING. MOST OF THESE NODULES, WHEN INDUCED UNDER SPECIAL EXPERIMENTAL CONDITIONS, MAY REGRESS OR REMODEL AND THUS THEY ARE NOT NEOPLASTIC IN NATURE. CHRONIC CARCINOGENICITY BIOASSAYS SHOULD INCLUDE "STOP" TYPE OF TREATMENT LEAVING ENOUGH OF THE OBSERVATIONAL TIME TO ESTABLISH THE FATE OF INDUCED NODULAR LESIONS. THE INDUCTION OF HISTOCHEMICALLY CHANGED FOCI CAN SERVE ONLY AS AN INDICATION OF POTENTIAL HEPATOCARCINOGENICITY AND SHOULD NOT BE EQUATED WITH THE INDUCTION OF BONA FIDE CANCER. THE BIOLOGIC INTERPRETATION OF NODULAR LIVER LESIONS, ESPECIALLY IN MICE, NEEDS FURTHER SCRUTINY BECAUSE THESE LESIONS HAVE A TENDENCY TO DEVELOP SPONTANEOUSLY WITH HIGH INCIDENCE IN SOME STRAINS. THIS CHARACTERISTIC THEN RAISES THE QUESTION AS TO THE MECHANISM BY WHICH VARIOUS AGENTS AUGMENT AND/OR ACCELERATE THE DEVELOPMENT OF SUCH TUMORS. IS THIS ACTION PRIMARILY PROMOTING OR INITIATING IN NATURE OR DOES IT REPRESENT THE INDUCTION OF TUMORS DE NOVO? THE ANSWER TO THIS DILEMMA MAY HAVE A DECISIVE BEARING ON CARCINOGENIC RISK ASSESSMENT AND THE TYPE OF REGULATORY ACTION, SINCE THE PROMOTING AGENTS POSSESS A THRESHOLD EFFECT AND THE PROMOTED CHANGES MAY REGRESS FOLLOWING WITHDRAWAL OF TREATMENT. THE INTERPRETATION OF HEPATOCARCINOGENESIS IS FURTHER COMPLICATED BY THE FACT THAT SEVERAL FACTORS, SUCH AS SEX HORMONAL ENVIRONMENT, INCREASED MITOTIC ACTIVITY FOLLOWING AN EXCESSIVE LOSS OF PARENCHYMAL CELLS, DEGREE OF CALORIC INTAKE, ENZYMATIC COMPLEMENT, AND ANIMALS' AGE AT THE TIME OF THE EXPOSURE TO A TEST AGENT, MAY INFLUENCE THE OUTCOME OF LIVER TUMOR DEVELOPMENT BY MODULATING "INITIATION" AND/OR "PROMOTION" OF CARCINOGENESIS. BROAD FLUCTUATION IN THE HISTORIC INCIDENCE OF LIVER TUMORS FURTHER COMPOUNDS THE COMPLEXITY OF THE PROPER BIOASSAY INTERPRETATION. THE SPECIFICALLY DESIGNED EXPERIMENTS MAY HAVE THE OBJECTIVE TO EXPLORE PREDOMINANTLY THE INITIATING OR PROMOTING EFFECTS OF THE AGENT. SUCH PROTOCOLS SHOULD BE USED WHENEVER NECESSARY TO DIFFERENTIATE BETWEEN THESE TWO MECHANISMS OF ACTION. IN THE CAUCASIANS, THE "SPONTANEOUS" DEVELOPMENT OF THE PRIMARY HEPATOCELLULAR TUMORS IS RARE. THE MAJORITY OF THESE TUMORS ARE MALIGNANT AND RAPIDLY FATAL. ACCORDING TO SOME HUMAN PATHOLOGISTS, THE BENIGN VARIETY OF LIVER TUMORS IS RARE AND IT DOES NOT REPRESENT NECESSARILY A PREMALIGNANT STAGE IN TUMOR DEVELOPMENT. CARCINOMA OF THE LIVER MAY OCCUR IN INFANCY, ESPECIALLY IN MALES BEFORE THE AGE OF 2 YEARS. THIS SUGGESTS A GENETIC CAUSATION OR CARCINOGENIC EXPOSURE IN UTERO. ONE OF THE GEOGRAPHIC FACTORS WHICH SIGNIFICANTLY ENHANCES THE INCIDENCE OF HEPATOCELLULAR CARCINOMA IN HUMANS IS EXPOSURE TO AFLATOXIN B(1) WHICH IS APPARENTLY POTENTIATED BY CONCURRENT LIVER CIRRHOSIS. BECAUSE MANY MORE AGENTS HAVE BEEN FOUND TO BE HEPATOCARCINOGENIC IN MICE AND RATS THAN IN MEN, A QUESTION ARISES AS TO THE DIRECT RELEVANCE OF RODENT STUDIES TO HUMANS. A BALANCED ASSESSMENT OF THE CARCINOGENICITY OF THE AGENT COULD ONLY BE REACHED IN CONSIDERING BOTH THE PHARMACOKINETICS AND THE DEVELOPMENT OF MALIGNANT NEOPLASIA IN OTHER ORGANS. IN THE CASE OF POSITIVE CARCINOGENICITY ASSESSMENT, THE OUTCOME OF THE MUTAGENICITY BIOASSAYS CAN SUGGEST GENIC (GENOTOXIC) OR PARAGENIC (EPIGENETIC) MODE OF ACTION IN MAMMALIAN SYSTEMS. 1982 13 5357 34 REACTIVE OXYGEN SPECIES INDUCE EPIGENETIC INSTABILITY THROUGH THE FORMATION OF 8-HYDROXYDEOXYGUANOSINE IN HUMAN HEPATOCARCINOGENESIS. CHRONIC HEPATITIS C (CHC) TRIGGERS OXIDATIVE STRESS AND CONTRIBUTES TO THE EMERGENCE OF HEPATOCELLULAR CARCINOMA (HCC). WE PREVIOUSLY REPORTED THAT TUMOR SUPPRESSOR GENE (TSG) METHYLATION IS A CRITICAL FACTOR DURING THE EARLY STAGES OF HEPATOCARCINOGENESIS. IN THIS STUDY, WE CLARIFY THE ASSOCIATION BETWEEN OXIDATIVE STRESS AND EPIGENETIC ALTERATIONS DURING HEPATOCARCINOGENESIS. WE EXAMINED DNA OXIDATION AND METHYLATION PROFILES IN 128 LIVER BIOPSY SAMPLES FROM CHC PATIENTS. THE DNA OXIDATION AND METHYLATED TSG NUMBERS WERE QUANTIFIED USING IMMUNOHISTOCHEMICAL ANALYSIS OF 8-HYDROXYDEOXYGUANOSINE (8-OHDG) AND QUANTITATIVE PCR FOR 11 TSGS, RESPECTIVELY. THE QUANTITATIVE CHROMATIN IMMUNOPRECIPITATION-PCR (CHIP-QPCR) ASSAY IN HEPG2 AND FETAL LIVER HC CELLS TREATED WITH H2O2 WAS USED TO QUANTIFY TRIMETHYL-H3K4, ACETYLATED-H4K16 (AN ACTIVE CHROMATIN MARKER), TRIMETHYL-H3K27 (A REPRESSIVE CHROMATIN MARKER) AND 8-OHDG. WE ANALYZED 30 PROMOTERS OF 25 DIFFERENT TSGS BY QPCR. THE HIGH LEVELS OF 8-OHDG WAS THE ONLY VARIABLE THAT WAS SIGNIFICANTLY ASSOCIATED WITH THE INCREASED NUMBER OF METHYLATED TSGS IN CHC (P < 0.0001). THE CHIP-QPCR REVEALED THAT AFTER H2O2 TREATMENT OF THE CELL LINES, THE 8-OHDG-BOUND PROMOTERS SHOWED A MODIFICATION FROM AN ACTIVE CHROMATIN (TRIMETHYL-H3K4 AND ACETYLATED-H4K16 DOMINANT) TO A REPRESSIVE CHROMATIN (TRIMETHYL-H3K27 DOMINANT) STATUS. WE CONCLUDE THAT OXIDATIVE STRESS ALTERS THE CHROMATIN STATUS, WHICH LEADS TO ABNORMAL METHYLATION OF TSGS, AND CONTRIBUTES TO HEPATOCARCINOGENESIS IN CHC PATIENTS. 2013 14 1646 38 DOES THE HEPATITIS B ANTIGEN HBX PROMOTE THE APPEARANCE OF LIVER CANCER STEM CELLS? HEPATITIS B VIRUS (HBV) IS A MAJOR ETIOLOGIC AGENT OF CHRONIC LIVER DISEASE AND HEPATOCELLULAR CARCINOMA (HCC). HBV-ENCODED X ANTIGEN, HBX, AND PATHWAYS IMPLICATED IN THE SELF-RENEWAL OF STEM CELLS CONTRIBUTE TO HCC, BUT IT IS NOT CLEAR WHETHER HBX EXPRESSION PROMOTES "STEMNESS." THUS, EXPERIMENTS WERE DESIGNED TO TEST THE HYPOTHESIS THAT HBX TRIGGERS MALIGNANT TRANSFORMATION BY PROMOTING PROPERTIES THAT ARE CHARACTERISTIC OF CANCER STEM CELLS (CSC). TO TEST THIS HYPOTHESIS, HEPG2 CELLS WERE STABLY TRANSDUCED WITH HBX AND THEN ASSAYED FOR PHENOTYPIC AND MOLECULAR CHARACTERISTICS OF "STEMNESS." THE RELATIONSHIP BETWEEN HBX AND "STEMNESS"-ASSOCIATED MARKERS WAS ALSO EVALUATED BY IMMUNOHISTOCHEMICAL STAINING OF LIVER AND TUMOR TISSUE SECTIONS FROM HBV-INFECTED PATIENTS. THE RESULTS SHOWED THAT OCT-4, NANOG, KLF-4, BETA-CATENIN, AND EPITHELIAL CELL ADHESION MOLECULE (EPCAM) WERE ACTIVATED BY HBX IN VITRO AND IN VIVO. EPCAM WAS DETECTED IN THE NUCLEI OF HUMAN HCC CELLS FROM INFECTED PATIENTS. HBX PROMOTES "STEMNESS" BY ACTIVATING BETA-CATENIN AND EPIGENETIC UPREGULATION OF MIR-181, BOTH OF WHICH TARGET EPCAM. HBX EXPRESSION WAS ALSO ASSOCIATED WITH DEPRESSED LEVELS OF E-CADHERIN. MOREOVER, HBX STIMULATED CELL MIGRATION, GROWTH IN SOFT AGAR, AND SPHEROID FORMATION. THIS WORK IS THE FIRST TO PROPOSE THAT HBV PROMOTES "STEMNESS" IN THE PATHOGENESIS OF HCC. HBX-ASSOCIATED UPREGULATED EXPRESSION OF MULTIPLE "STEMNESS" MARKERS SUPPORTS THE HYPOTHESIS THAT HBX CONTRIBUTES TO HEPATOCARCINOGENESIS, AT LEAST IN PART, BY PROMOTING CHANGES IN GENE EXPRESSION THAT ARE CHARACTERISTICS OF CSCS. 2011 15 3646 36 INCREASED PROTEIN EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) 1 IS SIGNIFICANTLY CORRELATED WITH THE MALIGNANT POTENTIAL AND POOR PROGNOSIS OF HUMAN HEPATOCELLULAR CARCINOMAS. ALTERATION OF DNA METHYLATION IS ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS. DNA METHYLTRANSFERASE (DNMT) 1 IS A MAJOR ENZYME INVOLVED IN ESTABLISHING GENOMIC METHYLATION PATTERNS. MOST OF THE STUDIES CONCERNING DNMT1 EXPRESSION IN HUMAN CANCERS HAVE BEEN PERFORMED ONLY AT THE MRNA LEVEL. TO DIRECTLY EXAMINE DNMT1 PROTEIN EXPRESSION LEVELS DURING HUMAN HEPATOCARCINOGENESIS, 16 HISTOLOGICALLY NORMAL LIVER TISSUES, 51 NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS, WHICH ARE CONSIDERED TO BE PRECANCEROUS CONDITIONS, AND 53 HEPATOCELLULAR CARCINOMAS (HCCS) WERE SUBJECTED TO IMMUNOHISTOCHEMIC EXAMINATION. IF MORE THAN 20% OF THE CELLS EXHIBITED NUCLEAR DNMT1 STAINING, THE TISSUE SAMPLE WAS CONSIDERED TO BE DNMT1-POSITIVE. DNMT1 IMMUNOREACTIVITY WAS OBSERVED IN 23 (43%) OF THE HCCS, BUT IN NONE (0%) OF THE HISTOLOGICALLY NORMAL LIVER OR NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS. THE INCIDENCE OF INCREASED DNMT1 PROTEIN EXPRESSION IN HCCS CORRELATED SIGNIFICANTLY WITH POOR TUMOR DIFFERENTIATION (P = 0.0006) AND PORTAL VEIN INVOLVEMENT (P = 0.0002). MOREOVER, THE RECURRENCE-FREE (P = 0.0001) AND OVERALL (P < 0.0001) SURVIVAL RATES OF PATIENTS WITH HCCS EXHIBITING INCREASED DNMT1 PROTEIN EXPRESSION WERE SIGNIFICANTLY LOWER THAN THOSE OF PATIENTS WITH HCCS THAT DID NOT EXHIBIT INCREASED EXPRESSION. INCREASED DNMT1 PROTEIN EXPRESSION MAY PLAY A CRITICAL ROLE IN THE MALIGNANT PROGRESSION OF HCCS AND BE A BIOLOGIC PREDICTOR OF BOTH HCC RECURRENCE AND A POOR PROGNOSIS IN HCC PATIENTS. 2003 16 4900 35 OXIDATIVE STRESS-INDUCED EPIGENETIC CHANGES ASSOCIATED WITH MALIGNANT TRANSFORMATION OF HUMAN KIDNEY EPITHELIAL CELLS. RENAL CELL CARCINOMA (RCC) IN HUMANS IS POSITIVELY INFLUENCED BY OXIDATIVE STRESS STATUS IN KIDNEYS. WE RECENTLY REPORTED THAT ADAPTIVE RESPONSE TO LOW LEVEL OF CHRONIC OXIDATIVE STRESS INDUCES MALIGNANT TRANSFORMATION OF IMMORTALIZED HUMAN RENAL TUBULAR EPITHELIAL CELLS. EPIGENETIC ALTERATIONS IN HUMAN RCC ARE WELL DOCUMENTED, BUT ITS ROLE IN OXIDATIVE STRESS-INDUCED MALIGNANT TRANSFORMATION OF KIDNEY CELLS IS NOT KNOWN. THEREFORE, THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE POTENTIAL ROLE OF EPIGENETIC CHANGES IN CHRONIC OXIDATIVE STRESS-INDUCED MALIGNANT TRANSFORMATION OF HK-2, HUMAN RENAL TUBULAR EPITHELIAL CELLS. THE RESULTS REVEALED ABERRANT EXPRESSION OF EPIGENETIC REGULATORY GENES INVOLVED IN DNA METHYLATION (DNMT1, DNMT3A AND MBD4) AND HISTONE MODIFICATIONS (HDAC1, HMT1 AND HAT1) IN HK-2 CELLS MALIGNANTLY TRANSFORMED BY CHRONIC OXIDATIVE STRESS. ADDITIONALLY, BOTH IN VITRO SOFT AGAR ASSAY AND IN VIVO NUDE MICE STUDY SHOWING DECREASED TUMORIGENIC POTENTIAL OF MALIGNANTLY TRANSFORMED HK-2 CELLS FOLLOWING TREATMENT WITH DNA DE-METHYLATING AGENT 5-AZA 2' DC FURTHER CONFIRMED THE CRUCIAL ROLE OF DNA HYPERMETHYALTION IN OXIDATIVE STRESS-INDUCED MALIGNANT TRANSFORMATION. CHANGES OBSERVED IN GLOBAL HISTONE H3 ACETYLATION (H3K9, H3K18, H3K27 AND H3K14) AND DECREASE IN PHOSPHO-H2AX (SER139) ALSO SUGGEST POTENTIAL ROLE OF HISTONE MODIFICATIONS IN INCREASED SURVIVAL AND MALIGNANT TRANSFORMATION OF HK-2 CELLS BY OXIDATIVE STRESS. IN SUMMARY, THE RESULTS OF THIS STUDY SUGGEST THAT EPIGENETIC REPROGRAMMING INDUCED BY LOW LEVELS OF OXIDATIVE STRESS ACT AS DRIVER FOR MALIGNANT TRANSFORMATION OF KIDNEY EPITHELIAL CELLS. FINDINGS OF THIS STUDY ARE HIGHLY RELEVANT IN POTENTIAL CLINICAL APPLICATION OF EPIGENETIC-BASED THERAPEUTICS FOR TREATMENTS OF KIDNEY CANCERS. 2017 17 1620 35 DNA METHYLTRANSFERASE-MEDIATED TRANSCRIPTIONAL SILENCING IN MALIGNANT GLIOMA: A COMBINED WHOLE-GENOME MICROARRAY AND PROMOTER ARRAY ANALYSIS. EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IS A COMMON FEATURE IN HUMAN CANCER. PROMOTER HYPERMETHYLATION AND HISTONE DEACETYLATION ARE REVERSIBLE EPIGENETIC MECHANISMS ASSOCIATED WITH TRANSCRIPTIONAL REGULATION. DNA METHYLTRANSFERASES (DNMT1 AND DNMT3B) REGULATE AND MAINTAIN PROMOTER METHYLATION AND ARE OVEREXPRESSED IN HUMAN CANCER. WE PERFORMED WHOLE-GENOME MICROARRAY ANALYSIS TO IDENTIFY GENES WITH ALTERED EXPRESSION AFTER RNAI-INDUCED SUPPRESSION OF DNMT IN A GLIOBLASTOMA MULTIFORME (GBM) CELL LINE. WE THEN IDENTIFIED GENES WITH BOTH DECREASED EXPRESSION AND EVIDENCE OF PROMOTER CPG ISLAND HYPERMETHYLATION IN GBM TISSUE SAMPLES USING A COMBINED WHOLE-GENOME MICROARRAY TRANSCRIPTOME ANALYSIS IN CONJUNCTION WITH A PROMOTER ARRAY ANALYSIS AFTER DNA IMMUNOPRECIPITATION WITH ANTI-5-METHYLCYTIDINE. DNMT1 AND 3B KNOCKDOWN RESULTED IN THE RESTORED EXPRESSION OF 308 GENES THAT ALSO CONTAINED PROMOTER REGION HYPERMETHYLATION. OF THESE, 43 WERE ALSO FOUND TO BE DOWNREGULATED IN GBM TISSUE SAMPLES. THREE DOWNREGULATED GENES WITH HYPERMETHYLATED PROMOTERS AND RESTORED EXPRESSION IN RESPONSE TO ACUTE DNMT SUPPRESSION WERE ASSAYED FOR METHYLATION CHANGES USING BISULFITE SEQUENCE ANALYSIS OF THE PROMOTER REGION AFTER CHRONIC DNMT SUPPRESSION. RESTORATION OF GENE EXPRESSION WAS NOT ASSOCIATED WITH CHANGES IN PROMOTER REGION METHYLATION, BUT RATHER WITH CHANGES IN HISTONE METHYLATION AND CHROMATIN CONFORMATION. TWO OF THE IDENTIFIED GENES EXHIBITED GROWTH SUPPRESSIVE ACTIVITY IN IN VITRO ASSAYS. COMBINING TARGETED GENETIC MANIPULATIONS WITH COMPREHENSIVE GENOMIC AND EXPRESSION ANALYSES PROVIDES A POTENTIALLY POWERFUL NEW APPROACH FOR IDENTIFYING EPIGENETICALLY REGULATED GENES IN GBM. 2009 18 3636 26 INCREASED DNA METHYLTRANSFERASE ACTIVITY AND DNA METHYLATION FOLLOWING EPIDERMAL GROWTH FACTOR STIMULATION IN OVARIAN CANCER CELLS. OVARIAN CANCER PROGRESSION IS CORRELATED WITH ACCUMULATION OF ABERRANT CPG ISLAND METHYLATION. IN OVARIAN CANCER, ASCITES FLUID CONTAINS NUMEROUS EPIDERMAL-GROWTH-FACTOR-RECEPTOR (EGFR) ACTIVATORS, WHICH COULD RESULT IN A TUMOR MICROENVIRONMENT OF CONSTANT EGFR ACTIVATION. SIGNALING PATHWAYS DOWNSTREAM OF EGFR, SUCH AS RAS, REGULATE DNA METHYLATION. WE HYPOTHESIZED THAT CHRONIC EGFR ACTIVATION COULD ALTER DNA METHYLATION. WE FOUND THAT EGFR ACTIVATION INCREASED DNA METHYLTRANSFERASE (DNMT) ACTIVITY ACUTELY, AS WELL AS AFTER LONG-TERM EGF TREATMENT OR EXPRESSION OF A MUTATIONALLY ACTIVATED EGFR. FURTHERMORE, THIS INCREASE IN DNMT ACTIVITY WAS DEPENDENT ON EGFR CATALYTIC ACTIVITY AND RESULTED IN INCREASED GLOBAL DNA METHYLATION. ADDITIONALLY, TREATMENT WITH THE DNMT INHIBITOR/HYPOMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE (AZA) INHIBITED THE EGF INDUCED INCREASE OF BOTH DNMT ACTIVITY AND GLOBAL METHYLATION. THESE DATA SUPPORT A ROLE FOR EGFR IN THE PROCESS OF ACCUMULATED DNA METHYLATION DURING OVARIAN CANCER PROGRESSION AND SUGGEST THAT EPIGENETIC THERAPY MAY BE BENEFICIAL FOR THE TREATMENT OF OVARIAN CANCER. 2012 19 737 45 CANCER STEM CELLS. THERE IS AN INCREASING EVIDENCE SUPPORTING THE CANCER STEM CELL HYPOTHESIS. NORMAL STEM CELLS IN THE ADULT ORGANISM ARE RESPONSIBLE FOR TISSUE RENEWAL AND REPAIR OF AGED OR DAMAGED TISSUE. A SUBSTANTIAL CHARACTERISTIC OF STEM CELLS IS THEIR ABILITY FOR SELF-RENEWAL WITHOUT LOSS OF PROLIFERATION CAPACITY WITH EACH CELL DIVISION. THE STEM CELLS ARE IMMORTAL, AND RATHER RESISTANT TO ACTION OF DRUGS. THEY ARE ABLE TO DIFFERENTIATE AND FORM SPECIFIC TYPES OF TISSUE DUE TO THE INFLUENCE OF MICROENVIRONMENTAL AND SOME OTHER FACTORS. STEM CELLS DIVIDE ASYMMETRICALLY PRODUCING TWO DAUGHTER CELLS -- ONE IS A NEW STEM CELL AND THE SECOND IS PROGENITOR CELL, WHICH HAS THE ABILITY FOR DIFFERENTIATION AND PROLIFERATION, BUT NOT THE CAPABILITY FOR SELF-RENEWAL. CANCER STEM CELLS ARE IN MANY ASPECTS SIMILAR TO THE STEM CELLS. IT HAS BEEN PROVEN THAT TUMOR CELLS ARE HETEROGENEOUS COMPRISING RARE TUMOR INITIATING CELLS AND ABUNDANT NON-TUMOR INITIATING CELLS. TUMOR INITIATING CELLS -- CANCER STEM CELLS HAVE THE ABILITY OF SELF-RENEWAL AND PROLIFERATION, ARE RESISTANT TO DRUGS, AND EXPRESS TYPICAL MARKERS OF STEM CELLS. IT IS NOT CLEAR WHETHER CANCER STEM CELLS ORIGINATE FROM NORMAL STEM CELLS IN CONSEQUENCE OF GENETIC AND EPIGENETIC CHANGES AND/OR BY REDIFFERENTIATION FROM SOMATIC TUMOR CELLS TO THE STEM-LIKE CELLS. PROBABLY BOTH MECHANISMS ARE INVOLVED IN THE ORIGIN OF CANCER STEM CELLS. DYSREGULATION OF STEM CELL SELF-RENEWAL IS A LIKELY REQUIREMENT FOR THE DEVELOPMENT OF CANCER. ISOLATION AND IDENTIFICATION OF CANCER STEM CELLS IN HUMAN TUMORS AND IN TUMOR CELL LINES HAS BEEN SUCCESSFUL. TO DATE, THE EXISTENCE OF CANCER STEM CELLS HAS BEEN PROVEN IN ACUTE AND CHRONIC MYELOID LEUKEMIA, IN BREAST CANCER, IN BRAIN TUMORS, IN LUNG CANCER AND GASTROINTESTINAL TUMORS. CANCER STEM CELL MODEL IS ALSO CONSISTENT WITH SOME CLINICAL OBSERVATIONS. ALTHOUGH STANDARD CHEMOTHERAPY KILLS MOST CELLS IN A TUMOR, CANCER STEM CELLS REMAIN VIABLE. DESPITE THE SMALL NUMBER OF SUCH CELLS, THEY MIGHT BE THE CAUSE OF TUMOR RECURRENCE, SOMETIMES MANY YEARS AFTER THE "SUCCESSFUL" TREATMENT OF PRIMARY TUMOR. GROWTH OF METASTASES IN DISTINCT AREAS OF BODY AND THEIR CELLULAR HETEROGENEITY MIGHT BE CONSEQUENCE OF CANCER STEM CELL DIFFERENTIATION AND/OR DEDIFFERENTIATION AND ASYMMETRIC DIVISION OF CANCER STEM CELLS. FURTHER CHARACTERIZATION OF CANCER STEM CELLS IS NEEDED IN ORDER TO FIND WAYS TO DESTROY THEM, WHICH MIGHT CONTRIBUTE SIGNIFICANTLY TO THE THERAPEUTIC MANAGEMENT OF MALIGNANT TUMORS. 2005 20 1632 30 DNMTS ARE INVOLVED IN TGF-BETA1-INDUCED EPITHELIAL-MESENCHYMAL TRANSITIONS IN AIRWAY EPITHELIAL CELLS. CHRONIC RHINOSINUSITIS (CRS) PATHOGENESIS IS CLOSELY RELATED TO TISSUE REMODELING, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION (EMT). EPIGENETIC MECHANISMS PLAY KEY ROLES IN EMT. DNA METHYLATION, MEDIATED BY DNA METHYLTRANSFERASES (DNMTS), IS AN EPIGENETIC MARKER THAT IS CRITICAL TO EMT. THE GOAL OF THIS STUDY WAS TO DETERMINE WHETHER DNMTS WERE INVOLVED IN TGF-BETA1-INDUCED EMT AND ELUCIDATE THE UNDERLYING MECHANISMS IN NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION AND DNMT ACTIVITY WERE QUANTIFIED. DNMT EXPRESSION WAS MEASURED USING REAL-TIME PCR (QRT-PCR) IN HUMAN CRS TISSUES. MRNA AND PROTEIN LEVELS OF DNMTS, E-CADHERIN, VIMENTIN, ALPHA-SMA, AND FIBRONECTIN WERE DETERMINED USING RT-PCR AND WESTERN BLOTTING, RESPECTIVELY. DNMT1, DNMT3A, AND DNMT3B GENE EXPRESSION WERE KNOCKED DOWN USING SIRNA TRANSFECTION. MAPK PHOSPHORYLATION AND EMT-RELATED TRANSCRIPTION FACTOR LEVELS WERE DETERMINED USING WESTERN BLOTTING. SIGNALING PATHWAYS WERE ANALYZED USING SPECIFIC INHIBITORS OF MAPK. WE DEMONSTRATED THESE DATA IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION, DNMT ACTIVITY, AND DNMT EXPRESSION INCREASED IN CRS TISSUES. DNMT EXPRESSION WAS POSITIVELY CORRELATED WITH LUND-MCKAY CT SCORES. TGF-BETA1 DOSE-DEPENDENTLY INDUCED DNMT EXPRESSION. FURTHER, 5-AZA INHIBITED TGF-BETA1-INDUCED DNMT, SNAIL, AND SLUG EXPRESSION RELATED TO EMT, AS WELL AS P38 AND JNK PHOSPHORYLATION IN A549 CELLS AND TGF-BETA1-INDUCED DNMT EXPRESSION AND EMT IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. TGF-BETA1-INDUCED DNMT EXPRESSION LEADS TO DNA METHYLATION AND EMT VIA P38, JNK, SNAIL, AND SLUG SIGNALING PATHWAYS. INHIBITION OF DNMT SUPPRESSED THE EMT PROCESS AND THEREFORE IS POTENTIALLY A CRS THERAPEUTIC STRATEGY. 2022