1 1658 134 DOWN-REGULATION OF A PRO-APOPTOTIC PATHWAY REGULATED BY PCAF/ADA3 IN EARLY STAGE GASTRIC CANCER. THE LOSS OF P300/CBP-ASSOCIATED PROTEIN (PCAF) EXPRESSION IS ASSOCIATED WITH POOR CLINICAL OUTCOME IN GASTRIC CANCER, AND A POTENTIAL BIO-MARKER FOR INVASIVE AND AGGRESSIVE TUMORS. HOWEVER, THE MECHANISM LINKING LOSS OF PCAF TO THE ONSET OF GASTRIC CANCER HAS NOT BEEN IDENTIFIED. GIVEN THAT PCAF AND ITS BINDING PARTNER TRANSCRIPTIONAL ADAPTOR PROTEIN 3 (ADA3) WERE RECENTLY SHOWN TO REGULATE THE INTRINSIC (MITOCHONDRIAL) PATHWAY TO APOPTOSIS VIA EPIGENETIC REGULATION OF PHOSPHOFURIN ACIDIC CLUSTER SORTING PROTEINS 1 AND 2 (PACS1, PACS2), WE ANALYZED PCAF, ADA3, AND PACS1/2 EXPRESSION IN 99 PATIENT-MATCHED SURGICAL SAMPLES RANGING FROM NORMAL GASTRIC MUCOSA, THROUGH PRE-MALIGNANT CHRONIC GASTRITIS AND INTESTINAL METAPLASIA TO STAGE I-III INVASIVE CANCERS. PCAF MRNA LEVELS WERE NOT REDUCED IN EITHER PRE-MALIGNANT STATE BUT WERE SIGNIFICANTLY DOWN-REGULATED IN ALL STAGES OF GASTRIC CANCER, COMMENCING AT AJCC STAGE I (P < 0.05), THUS LINKING REDUCED PCAF EXPRESSION WITH EARLY MALIGNANT CHANGE. FURTHERMORE, PATIENTS WITH COMBINED REDUCTION OF PCAF AND PACS1 HAD SIGNIFICANTLY POORER OVERALL SURVIVAL (P = 0.0257), CONFIRMED IN AN INDEPENDENT DATASET OF 359 PATIENTS (P = 5.8 X 10E-6). AT THE PROTEIN LEVEL, PCAF, ADA3, AND PACS1 EXPRESSION WERE ALL SIGNIFICANTLY DOWN-REGULATED IN INTESTINAL-TYPE GASTRIC CANCER, AND CORRELATED WITH REDUCED PROGRESSION FREE SURVIVAL. WE CONCLUDE THAT A PRO-APOPTOTIC MECHANISM CENTERED ON THE INTRINSIC (MITOCHONDRIAL) PATHWAY AND REGULATED BY PCAF/ADA3 CAN INFLUENCE THE PROGRESSION FROM PREMALIGNANT TO MALIGNANT CHANGE, AND THUS ACT AS A TUMOR SUPPRESSION MECHANISM IN GASTRIC CANCER. 2018 2 2453 39 EPIGENETIC SUPPRESSION OF THE IMMUNOREGULATOR MZB1 IS ASSOCIATED WITH THE MALIGNANT PHENOTYPE OF GASTRIC CANCER. PREDICTION OF TUMOR RECURRENCE AFTER CURATIVE RESECTION IS CRITICAL FOR DETERMINING THE PROGNOSIS OF PATIENTS WITH GASTRIC CANCER (GC). THE INITIATION AND PROGRESSION OF GC ARE ASSOCIATED WITH INAPPROPRIATE IMMUNE RESPONSES CAUSED BY CHRONIC INFLAMMATION OF THE GASTRIC MUCOSA. TO IDENTIFY IMMUNOREGULATORY MOLECULES INVOLVED IN GC PROGRESSION, GC CELL LINES AND 200 PAIRS OF TUMOR AND NORMAL TISSUES FROM PATIENTS WITH GC WERE ANALYZED FOR GENE EXPRESSION, AMPLIFICATION AND METHYLATION AS WELL AS FUNCTION OF A DIFFERENTIALLY EXPRESSED GENE. THE TRANSCRIPTOME ANALYSIS REVEALED THAT MARGINAL ZONE B AND B1 CELL SPECIFIC PROTEIN (MZB1) WAS EXPRESSED AT SIGNIFICANTLY DECREASED LEVELS IN PRIMARY GC TISSUES WHEN COMPARED WITH THE CORRESPONDING NORMAL GASTRIC MUCOSA. PCR ARRAY ANALYSIS EXPLORING GENES EXPRESSED COOPERATIVELY WITH MZB1 REVEALED THAT DIFFERENTIAL EXPRESSION OF MZB1 MRNA IN GC CELL LINES CORRELATED POSITIVELY WITH THE LEVELS OF THE MRNAS ENCODING ESTROGEN RECEPTOR 1 AND DESUMOYLATING ISOPEPTIDASE 1. HYPERMETHYLATION OF THE MZB1 PROMOTER WAS FREQUENT IN CELL LINES WITH DECREASED LEVELS OF MZB1 MRNA. SIRNA-MEDIATED KNOCKDOWN OF MZB1 SIGNIFICANTLY INCREASED PROLIFERATION, INVASION AND MIGRATION OF GC CELL LINES. LOW MZB1 EXPRESSION WAS AN INDEPENDENT PROGNOSTIC FACTOR FOR RECURRENCE AFTER CURATIVE GASTRECTOMY AND WAS ASSOCIATED SIGNIFICANTLY WITH INCREASED HEMATOGENOUS RECURRENCE. MZB1 ACTS AS A SUPPRESSOR OF GC. LOW MZB1 EXPRESSION IN THE PRIMARY GC TISSUE IS PREDICTIVE OF RECURRENCE AFTER CURATIVE RESECTION. 2016 3 3718 36 INHIBITION OF BCL6B PROMOTES GASTRIC CANCER BY AMPLIFYING INFLAMMATION IN MICE. BACKGROUND: CHRONIC GASTRITIS HAS BEEN DEMONSTRATED TO BE A KEY CAUSE OF GASTRIC CANCER (GC), AND CONTROL OF GASTRIC INFLAMMATION IS REGARDED AS AN EFFECTIVE TREATMENT FOR THE CLINICAL PREVENTION OF GASTRIC CARCINOGENESIS. HOWEVER, THERE REMAINS AN UNMET NEED TO IDENTIFY THE DOMINANT REGULATORS OF GASTRIC ONCOGENESIS-ASSOCIATED INFLAMMATION IN VIVO. METHODS: THE MOUSE MODEL FOR THE STUDY OF INFLAMMATION-ASSOCIATED GC WAS INDUCED BY BENZO[A]PYRENE (BAP) INTRAGASTRIC ADMINISTRATION IN BCL6B(-/-) AND WILDTYPE MICE ON A C57BL/6 BACKGROUND. 5-AZA-2'-DEOXYCYTIDINE (5-AZA), THE DEMETHYLATION DRUG, WAS INTRAPERITONEALLY INJECTED TO RESTORE BCL6B EXPRESSION. HUMAN GC TISSUE ARRAY WAS USED TO ANALYSE PATIENT SURVIVAL BASED ON BCL6B AND CD3 PROTEIN EXPRESSION. RESULTS: BCL6B WAS GRADUALLY DOWNREGULATED BY ITS OWN PROMOTER HYPERMETHYLATION IN PARALLEL TO AN INCREASING INFLAMMATORY RESPONSE DURING THE PROGRESSION OF BAP-INDUCED GASTRIC CARCINOGENESIS IN MICE. MOREOVER, KNOCKOUT OF BCL6B DRAMATICALLY WORSENED THE SEVERITY OF GASTRIC CANCER AND AGGRAVATED THE INFLAMMATORY RESPONSE IN THE BAP-INDUCED MICE GC MODEL. RE-ACTIVATION OF BCL6B BY 5-AZA IMPEDED INFLAMMATORY AMPLIFICATION AND BAP-INDUCED GC DEVELOPMENT, PROLONGING SURVIVAL TIME IN WILDTYPE MICE, WHEREAS NO NOTABLE CURATIVE EFFECT OCCURRED IN BCL6B(-/-) MICE WITH 5-AZA TREATMENT. FINALLY, SIGNIFICANT NEGATIVE CORRELATIONS WERE DETECTED BETWEEN THE MRNA LEVELS OF BCL6B AND INFLAMMATORY CYTOKINES IN HUMAN GC TISSUES; PATIENTS HARBOURING BCL6B-NEGETIVE AND SEVERE-INFLAMMATION GC TUMOURS WERE FOUND TO EXHIBIT THE SHORTEST SURVIVAL TIME. CONCLUSIONS: EPIGENETIC INACTIVATION OF BCL6B PROMOTES GASTRIC CANCER THROUGH AMPLIFICATION OF THE GASTRIC INFLAMMATORY RESPONSE IN VIVO AND OFFERS A NEW APPROACH FOR GC TREATMENT AND REGENERATIVE MEDICINE. 2019 4 1966 32 EPIGENETIC ALTERATION OF PRKCDBP IN COLORECTAL CANCERS AND ITS IMPLICATION IN TUMOR CELL RESISTANCE TO TNFALPHA-INDUCED APOPTOSIS. PURPOSE: PRKCDBP IS A PUTATIVE TUMOR SUPPRESSOR IN WHICH ALTERATION HAS BEEN OBSERVED IN SEVERAL HUMAN CANCERS. WE INVESTIGATED EXPRESSION AND FUNCTION OF PRKCDBP IN COLORECTAL CELLS AND TISSUES TO EXPLORE ITS CANDIDACY AS A SUPPRESSOR IN COLORECTAL TUMORIGENESIS. EXPERIMENTAL DESIGN: EXPRESSION AND METHYLATION STATUS OF PRKCDBP AND ITS EFFECT ON TUMOR GROWTH WERE EVALUATED. TRANSCRIPTIONAL REGULATION BY NF-KAPPAB SIGNALING WAS DEFINED BY LUCIFERASE REPORTER AND CHROMATIN IMMUNOPRECIPITATION ASSAYS. RESULTS: PRKCDBP EXPRESSION WAS HARDLY DETECTABLE IN 29 OF 80 (36%) PRIMARY TUMORS AND 11 OF 19 (58%) CELL LINES, AND ITS ALTERATION CORRELATED WITH TUMOR STAGE AND GRADE. PROMOTER HYPERMETHYLATION WAS COMMONLY FOUND IN CANCERS. PRKCDBP EXPRESSION INDUCED THE G(1) CELL-CYCLE ARREST AND INCREASED CELLULAR SENSITIVITY TO VARIOUS APOPTOTIC STRESSES. PRKCDBP WAS INDUCED BY TNFALPHA, AND ITS LEVEL CORRELATED WITH TUMOR CELL SENSITIVITY TO TNFALPHA-INDUCED APOPTOSIS. PRKCDBP INDUCTION BY TNFALPHA WAS DISRUPTED BY BLOCKING NF-KAPPAB SIGNALING WHILE IT WAS ENHANCED BY RELA TRANSFECTION. THE PRKCDBP PROMOTER ACTIVITY WAS INCREASED IN RESPONSE TO TNFALPHA, AND THIS RESPONSE WAS ABOLISHED BY DISRUPTION OF A KAPPAB SITE IN THE PROMOTER. PRKCDBP DELAYED THE FORMATION AND GROWTH OF XENOGRAFT TUMORS AND IMPROVED TUMOR RESPONSE TO TNFALPHA-INDUCED APOPTOSIS. CONCLUSIONS: PRKCDBP IS A PROAPOPTOTIC TUMOR SUPPRESSOR WHICH IS COMMONLY ALTERED IN COLORECTAL CANCER BY PROMOTER HYPERMETHYLATION, AND ITS GENE TRANSCRIPTION IS DIRECTLY ACTIVATED BY NF-KAPPAB IN RESPONSE TO TNFALPHA. THIS SUGGESTS THAT PRKCDBP INACTIVATION MAY CONTRIBUTE TO TUMOR PROGRESSION BY REDUCING CELLULAR SENSITIVITY TO TNFALPHA AND OTHER STRESSES, PARTICULARLY UNDER CHRONIC INFLAMMATORY MICROENVIRONMENT. 2011 5 1334 27 DEREGULATION OF AIOLOS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS THAT ARE RESISTANT TO APOPTOSIS. AIOLOS, A MEMBER OF THE IKAROS FAMILY OF ZINC-FINGER TRANSCRIPTION FACTORS, PLAYS AN IMPORTANT ROLE IN THE CONTROL OF MATURE B LYMPHOCYTE DIFFERENTIATION AND MATURATION. IN THIS STUDY, WE SHOWED THAT AIOLOS EXPRESSION IS UP-REGULATED IN B-CLL CELLS. THIS OVEREXPRESSION DOES NOT IMPLICATE ISOFORM IMBALANCE OR DISTURB AIOLOS SUBCELLULAR LOCALIZATION. THE CHROMATIN STATUS AT THE AIOLOS PROMOTER IN CLL IS DEFINED BY THE DEMETHYLATION OF DNA AND AN ENRICHMENT OF EUCHROMATIN ASSOCIATED HISTONE MARKERS, SUCH AS THE DIMETHYLATION OF THE LYSINE 4 ON HISTONE H3. THESE EPIGENETIC MODIFICATIONS SHOULD ALLOW ITS UPSTREAM EFFECTORS, SUCH AS NUCLEAR FACTOR-KAPPAB, CONSTITUTIVELY ACTIVATED IN CLL, TO GAIN ACCESS TO PROMOTER, RESULTING UP-REGULATION OF AIOLOS. TO DETERMINE THE CONSEQUENCES OF AIOLOS DEREGULATION IN CLL, WE ANALYZED THE EFFECTS OF AIOLOS OVEREXPRESSION OR DOWN-REGULATION ON APOPTOSIS. AIOLOS IS INVOLVED IN CELL SURVIVAL BY REGULATING THE EXPRESSION OF SOME BCL-2 FAMILY MEMBERS. OUR RESULTS STRONGLY SUGGEST THAT AIOLOS DEREGULATION BY EPIGENETIC MODIFICATIONS MAY BE A HALLMARK OF CLL. 2011 6 2761 32 EXPRESSION OF TESTIS-SPECIFIC GENES, TEX101 AND ODF4, IN CHRONIC MYELOID LEUKEMIA AND EVALUATION OF TEX101 IMMUNOGENICITY. BACKGROUND AND OBJECTIVES: CANCER-TESTIS (CT) ANTIGENS ARE A GROUP OF ANTIGENS WITH A RESTRICTED EXPRESSION IN NORMAL TISSUES, EXCEPT TESTIS, AND THEY HAVE ABERRANT EXPRESSION IN DIFFERENT TUMORS. THIS PATTERN OF EXPRESSION HAS MADE THEM PROMISING TARGETS FOR IMMUNOTHERAPY AND CANCER DETECTION. OUR AIM WAS TO FIND NEW MEMBERS OF THIS GROUP THAT MIGHT BE USEFUL AS MARKERS IN THE DETECTION OF CANCER AND IMMUNOTHERAPY. DESIGN AND SETTING: A DESCRIPTIVE STUDY CONDUCTED IN REFERRAL CENTERS OF TEHRAN UNIVERSITY OF MEDICAL SCIENCE FROM JANUARY 2008 TO JANUARY 2009. PATIENTS AND METHODS: WE ANALYZED THE EXPRESSION OF TWO TESTIS-SPECIFIC GENES NAMED ODF4 (OUTER DENSE FIBER OF SPERM TAILS 4) AND TEX101 (TESTIS EXPRESSED 101) IN 20 CHRONIC MYELOID LEUKEMIA (CML) AND 20 NORMAL SAMPLES BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION AND SEQUENCING. IMMUNOGENICITY OF TEX101 WAS EVALUATED BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY. RESULTS: THESE TWO GENES WERE EXPRESSED IN 30% OF CML PATIENTS BUT NOT IN ANY OF THE HEALTHY DONORS. HUMORAL RESPONSE AGAINST TEX101 WAS NOT DETECTED IN ANY SAMPLES. CONCLUSIONS: TEX101 AND ODF4 ARE CT GENES USEFUL FOR DETECTION OF CML. UNLIKE MANY CT GENES, OVEREXPRESSION OF TEX101 WAS NOT SHOWN TO INDUCE IMMUNOLOGIC RESPONSES IN THESE SAMPLES. ACCORDING TO THE PREVIOUS STUDIES, OVEREXPRESSION OF TEX101 LEADS TO SUPPRESSION OF CANCER INVASION AND METASTASIS; THUS, THE INDUCTION OF THE EXPRESSION OF TEX101 IN CANCER BY EPIGENETIC MECHANISMS MAY BE A TREATMENT STRATEGY. 2012 7 2763 30 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS. 2010 8 493 24 ASSESSMENT OF P53 AND ATM FUNCTIONALITY IN CHRONIC LYMPHOCYTIC LEUKEMIA BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION. THE ATM-P53 DNA-DAMAGE RESPONSE (DDR) PATHWAY HAS A CRUCIAL ROLE IN CHEMORESISTANCE IN CLL, AS INDICATED BY THE ADVERSE PROGNOSTIC IMPACT OF GENETIC ABERRATIONS OF TP53 AND ATM. IDENTIFYING AND DISTINGUISHING TP53 AND ATM FUNCTIONAL DEFECTS HAS BECOME RELEVANT AS EPIGENETIC AND POSTTRANSCRIPTIONAL DYSREGULATION OF THE ATM/P53 AXIS IS INCREASINGLY BEING RECOGNIZED AS THE UNDERLYING CAUSE OF CHEMORESISTANCE. ALSO, SPECIFIC TREATMENTS SENSITIZING TP53- OR ATM-DEFICIENT CLL CELLS ARE EMERGING. WE THEREFORE DEVELOPED A NEW ATM-P53 FUNCTIONAL ASSAY WITH THE AIM TO (I) IDENTIFY AND (II) DISTINGUISH ABNORMALITIES OF TP53 VERSUS ATM AND (III) ENABLE THE IDENTIFICATION OF ADDITIONAL DEFECTS IN THE ATM-P53 PATHWAY. REVERSED TRANSCRIPTASE MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION (RT-MLPA) WAS USED TO MEASURE ATM AND/OR P53-DEPENDENT GENES AT THE RNA LEVEL FOLLOWING DNA DAMAGE USING IRRADIATION. HERE, WE SHOWED THAT THIS ASSAY IS ABLE TO IDENTIFY AND DISTINGUISH THREE SUBGROUPS OF CLL TUMORS (I.E., TP53-DEFECTIVE, ATM-DEFECTIVE AND WT) AND IS ALSO ABLE TO DETECT ADDITIONAL SAMPLES WITH A DEFECTIVE DDR, WITHOUT MOLECULAR ABERRATIONS IN TP53 AND/OR ATM. THESE FINDINGS MAKE THE ATM-P53 RT-MLPA FUNCTIONAL ASSAY A PROMISING PROGNOSTIC TOOL FOR PREDICTING TREATMENT RESPONSES IN CLL. 2015 9 3439 37 HYPERMETHYLATION AND LOSS OF EXPRESSION OF GLUTATHIONE PEROXIDASE-3 IN BARRETT'S TUMORIGENESIS. CHRONIC GASTROESOPHAGEAL REFLUX DISEASE IS A KNOWN RISK FACTOR FOR BARRETT'S ESOPHAGUS (BE), WHICH INDUCES OXIDATIVE MUCOSAL DAMAGE. GLUTATHIONE PEROXIDASE-3 (GPX3) IS A SECRETORY PROTEIN WITH POTENT EXTRACELLULAR ANTIOXIDANT ACTIVITY. IN THIS STUDY, WE HAVE INVESTIGATED THE MRNA AND PROTEIN EXPRESSION OF GPX3, AND EXPLORED PROMOTER HYPERMETHYLATION AS AN EPIGENETIC MECHANISM FOR GPX3 GENE INACTIVATION DURING BARRETT'S CARCINOGENESIS. QUANTITATIVE REAL-TIME REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION ON 42 BARRETT'S ADENOCARCINOMAS (BAS) REVEALED CONSISTENTLY REDUCED LEVELS OF GPX3 MRNA IN 91% OF TUMOR SAMPLES. GPX3 PROMOTER HYPERMETHYLATION WAS DETECTED IN 62% OF BARRETT'S METAPLASIA, 82% OF DYSPLASIA, AND 88% OF BA SAMPLES. HYPERMETHYLATION OF BOTH ALLELES OF GPX3 WAS MOST FREQUENTLY SEEN IN BAS (P = .001). IMMUNOHISTOCHEMICAL STAINING OF GPX3 IN MATCHING TISSUE SECTIONS (NORMAL, BE, BARRETT'S DYSPLASIA, AND BA) REVEALED STRONG IMMUNOSTAINING FOR GPX3 IN NORMAL ESOPHAGEAL AND GASTRIC TISSUES. HOWEVER, WEAK TO ABSENT GPX3 STAINING WAS OBSERVED IN BARRETT'S DYSPLASIA AND ADENOCARCINOMA SAMPLES WHERE THE PROMOTER WAS HYPERMETHYLATED. THE DEGREE OF LOSS OF IMMUNOHISTOCHEMISTRY CORRELATED WITH THE HYPERMETHYLATION PATTERN (MONOALLELIC VERSUS BIALLELIC). THE OBSERVED HIGH FREQUENCY OF PROMOTER HYPERMETHYLATION AND PROGRESSIVE LOSS OF GPX3 EXPRESSION IN BA AND ITS ASSOCIATED LESIONS, TOGETHER WITH ITS KNOWN FUNCTION AS A POTENT ANTIOXIDANT, SUGGEST THAT EPIGENETIC INACTIVATION AND REGULATION OF GLUTATHIONE PATHWAY MAY BE CRITICAL IN THE DEVELOPMENT AND PROGRESSION OF BE. 2005 10 136 29 ABERRANT DNA HYPERMETHYLATION PATTERNS LEAD TO TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS OF MICE. OVEREXPOSURE OF THE HUMAN SKIN TO SOLAR ULTRAVIOLET (UV) RADIATION IS THE MAJOR ETIOLOGIC FACTOR FOR DEVELOPMENT OF SKIN CANCERS. HERE, WE REPORT THE RESULTS OF EPIGENETIC MODIFICATIONS IN UV-EXPOSED SKIN AND SKIN TUMORS IN A SYSTEMATIC MANNER. THE SKIN AND TUMOR SAMPLES WERE COLLECTED AFTER CHRONIC EXPOSURE OF THE SKIN OF SKH-1 HAIRLESS MICE TO UVB RADIATION USING A WELL-ESTABLISHED PHOTOCARCINOGENESIS PROTOCOL. WE FOUND A DISTINCT DNA HYPERMETHYLATION PATTERN IN THE UVB-EXPOSED EPIDERMAL SKIN AND UVB-INDUCED SKIN TUMORS THAT WAS ASSOCIATED WITH THE ELEVATED EXPRESSION AND ACTIVITY OF THE DNA METHYLTRANSFERASES (DNMT) 1, DNMT3A AND DNMT3B. TO EXPLORE THE ROLE OF HYPERMETHYLATION IN SKIN PHOTOCARCINOGENESIS, WE FOCUSED ON THE P16(INK4A) AND RASSF1A TUMOR SUPPRESSOR GENES, WHICH ARE TRANSCRIPTIONALLY SILENCED ON METHYLATION. WE ESTABLISHED THAT THE SILENCING OF THESE GENES IN UVB-EXPOSED EPIDERMIS AND UVB-INDUCED SKIN TUMORS IS ASSOCIATED WITH A NETWORK OF EPIGENETIC MODIFICATIONS, INCLUDING HYPOACETYLATION OF HISTONE H3 AND H4 AND INCREASED HISTONE DEACETYLATION, AS WELL AS RECRUITMENT OF METHYL-BINDING PROTEINS, INCLUDING MECP2 AND MBD1, TO THE METHYLATED CPGS. HIGHER LEVELS OF DNA METHYLATION AND DNMT ACTIVITY IN HUMAN SQUAMOUS CELL CARCINOMA SPECIMENS THAN IN NORMAL HUMAN SKIN SUGGEST THAT THE DATA ARE RELEVANT CLINICALLY. OUR DATA INDICATE FOR THE FIRST TIME THAT UVB-INDUCED DNA HYPERMETHYLATION, ENHANCED DNMT ACTIVITY AND HISTONE MODIFICATIONS OCCUR IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS AND SUGGEST THAT THESE EVENTS ARE INVOLVED IN THE SILENCING OF TUMOR SUPPRESSOR GENES AND IN SKIN TUMOR DEVELOPMENT. 2011 11 3049 32 GENOME-WIDE ANALYSIS REVEALS ZINC TRANSPORTER ZIP9 REGULATED BY DNA METHYLATION PROMOTES RADIATION-INDUCED SKIN FIBROSIS VIA THE TGF-BETA SIGNALING PATHWAY. RADIATION-INDUCED SKIN FIBROSIS IS A DETRIMENTAL AND CHRONIC DISORDER THAT OCCURS AFTER RADIATION EXPOSURE. DNA METHYLATION HAS BEEN CHARACTERIZED AS AN IMPORTANT REGULATORY MECHANISM OF MULTIPLE PATHOLOGICAL PROCESSES. IN THIS STUDY, WE COMPARED THE GENOME-WIDE DNA METHYLATION STATUS IN RADIATION-INDUCED FIBROTIC SKIN AND ADJACENT NORMAL TISSUES OF RATS BY METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING. RADIATION-INDUCED FIBROTIC SKIN SHOWED DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH 3,650 PROTEIN-CODING GENES, 72 MICRORNAS, 5,836 LONG NONCODING RNAS AND 3 PIWI-INTERACTING RNAS. BY INTEGRATING THE MRNA AND METHYLATION PROFILES, THE ZINC TRANSPORTER SLC39A9/ZIP9 WAS INVESTIGATED IN GREATER DETAIL. THE PROTEIN LEVEL OF ZIP9 WAS INCREASED IN IRRADIATED SKIN TISSUES OF HUMANS, MONKEYS, AND RATS, ESPECIALLY IN RADIOGENIC FIBROTIC SKIN TISSUES. RADIATION INDUCED THE DEMETHYLATION OF A CPG DINUCLEOTIDE IN EXON 1 OF ZIP9 THAT RESULTED IN RECRUITMENT OF THE TRANSCRIPTIONAL FACTOR SP1 AND INCREASED ZIP9 EXPRESSION. OVEREXPRESSION OF ZIP9 RESULTED IN ACTIVATION OF THE PROFIBROTIC TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY THROUGH PROTEIN KINASE B IN HUMAN FIBROBLASTS. IN ADDITION, RADIATION-INDUCED SKIN FIBROSIS WAS ASSOCIATED WITH INCREASED ZINC ACCUMULATION. THE ZINC CHELATOR N,N,N',N'-TETRAKIS(2-PYRIDYLMETHYL)-1,2-ETHYLENEDIAMINE ABROGATED ZIP9-INDUCED ACTIVATION OF THE TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY AND ATTENUATED RADIATION-INDUCED SKIN FIBROSIS IN A RAT MODEL. IN SUMMARY, OUR FINDINGS ILLUSTRATE EPIGENETIC REGULATION OF ZIP9 AND ITS CRITICAL ROLE IN PROMOTING RADIATION-INDUCED SKIN FIBROSIS. 2020 12 2767 38 EXPRESSION, PROGNOSTIC VALUE, AND FUNCTIONAL MECHANISM OF THE KDM5 FAMILY IN PANCREATIC CANCER. BACKGROUND: THE HISTONE LYSINE DEMETHYLASE KDM5 FAMILY IS AN IMPORTANT EPIGENETIC STATE-MODIFYING ENZYME FAMILY. INCREASING EVIDENCE SUPPORTS THAT EPIGENETIC ABNORMALITIES IN THE KDM5 FAMILY ARE RELATED TO MULTIPLE CANCERS IN HUMANS. HOWEVER, THE ROLE OF THE KDM5 FAMILY IN PANCREATIC CANCER IS NOT CLEAR, AND RELATED RESEARCH IS VERY SCARCE. METHODS: R SOFTWARE, KAPLAN-MEIER PLOTTER, CBIOPORTAL, TIMER, LINKEDOMICS, STRING, METASCAPE, TISIDB, AND THE GSCA LITE ONLINE TOOL WERE UTILIZED FOR BIOINFORMATICS ANALYSIS. RESULTS: KDM5A/B/C WAS SIGNIFICANTLY OVEREXPRESSED IN MANY KINDS OF TUMOR TISSUES, INCLUDING PANCREATIC ADENOCARCINOMA (PAAD), WHILE THE EXPRESSION OF KDM5D WAS SIGNIFICANTLY DOWNREGULATED. THE HIGH EXPRESSION OF KDM5A/B/C WAS RELATED TO POOR CLINICAL FEATURES, SUCH AS WORSE TREATMENT EFFICACY, HIGHER TUMOR GRADE, AND MORE ADVANCED CLINICAL STAGE. PATIENTS WITH A FAMILY HISTORY OF BREAST CANCER AND MELANOMA, HISTORY OF DRINKING OR HISTORY CHRONIC PANCREATITIS WERE MORE LIKELY TO HAVE KDM5A/B/C GENE ABNORMALITIES, WHICH WERE RELATED TO A VARIETY OF ADVERSE CLINICAL FEATURES. THE RESULTS OF GENE ONTOLOGY (GO) AND KYOTO ENCYCLOPEDIA OF GENES AND GENOMES (KEGG) PATHWAY ANALYSES OF THE KDM5 FAMILY AND ITS 800 CO-EXPRESSED GENES SHOWED THAT MANY GENE TERMS RELATED TO CELL PROLIFERATION, MIGRATION AND MANY CARCINOGENIC PATHWAYS. NOTABLY, WE FOUND THAT THE EXPRESSION LEVEL OF KDM5A/B/C WAS POSITIVELY CORRELATED WITH THE EXPRESSION OF MULTIPLE KEY DRIVER GENES SUCH AS KRAS, BRCA1, AND BRCA2 ETC. IN ADDITION, PPI NETWORK ANALYSIS SHOWED KDM5 FAMILY PROTEINS HAVE STRONG INTERACTIONS WITH HISTONE DEACETYLASE FAMILY 1 (HDAC1), WHICH COULD MODIFY THE LYSINES OF HISTONE H3, AND CO-ACT ON MANY PATHWAYS, INCLUDING THE "LONGEVITY-REGULATING PATHWAY" AND "NOTCH SIGNALING PATHWAY". MOREOVER, THE UPREGULATION OF KDM5A/B/C EXPRESSION WAS ASSOCIATED WITH AN INCREASE IN THE INFILTRATION OF B CELLS, CD8(+) T CELLS AND OTHER INFILTRATING IMMUNE LYMPHOCYTES AND THE EXPRESSION LEVELS OF IMMUNE MOLECULES SUCH AS NT5E AND CD274. INTERESTINGLY, THE OVEREXPRESSION OF KDM5A/C WAS ALSO CORELATED WITH REDUCED SENSITIVITY OF PANCREATIC CANCER CELLS TO MANY KINDS OF PANCREATIC CANCER-TARGETING OR CHEMOTHERAPEUTIC DRUGS, INCLUDING AXITINIB AND GEMCITABINE. CONCLUSION: KDM5 FAMILY MEMBERS MAY BE PROGNOSTIC MARKERS AND NEW THERAPEUTIC TARGETS FOR PATIENTS WITH PANCREATIC CANCER. 2022 13 5101 28 POLYCOMB FACTOR PHF19 CONTROLS CELL GROWTH AND DIFFERENTIATION TOWARD ERYTHROID PATHWAY IN CHRONIC MYELOID LEUKEMIA CELLS. POLYCOMB GROUP (PCG) OF PROTEINS ARE A GROUP OF HIGHLY CONSERVED EPIGENETIC REGULATORS INVOLVED IN MANY BIOLOGICAL FUNCTIONS, SUCH AS EMBRYONIC DEVELOPMENT, CELL PROLIFERATION, AND ADULT STEM CELL DETERMINATION. PHD FINGER PROTEIN 19 (PHF19) IS AN ASSOCIATED FACTOR OF POLYCOMB REPRESSOR COMPLEX 2 (PRC2), OFTEN UPREGULATED IN HUMAN CANCERS. IN PARTICULAR, MYELOID LEUKEMIA CELL LINES SHOW INCREASED LEVELS OF PHF19, YET LITTLE IS KNOWN ABOUT ITS FUNCTION. HERE, WE HAVE CHARACTERIZED THE ROLE OF PHF19 IN MYELOID LEUKEMIA CELLS. WE DEMONSTRATED THAT PHF19 DEPLETION DECREASES CELL PROLIFERATION AND PROMOTES CHRONIC MYELOID LEUKEMIA (CML) DIFFERENTIATION. MECHANISTICALLY, WE HAVE SHOWN HOW PHF19 REGULATES THE PROLIFERATION OF CML THROUGH A DIRECT REGULATION OF THE CELL CYCLE INHIBITOR P21. FURTHERMORE, WE OBSERVED THAT MTF2, A PHF19 HOMOLOG, PARTIALLY COMPENSATES FOR PHF19 DEPLETION IN A SUBSET OF TARGET GENES, INSTRUCTING SPECIFIC ERYTHROID DIFFERENTIATION. TAKEN TOGETHER, OUR RESULTS SHOW THAT PHF19 IS A KEY TRANSCRIPTIONAL REGULATOR FOR CELL FATE DETERMINATION AND COULD BE A POTENTIAL THERAPEUTIC TARGET FOR MYELOID LEUKEMIA TREATMENT. 2021 14 155 22 ABERRANT METHYLATION OF POLO-LIKE KINASE CPG ISLANDS IN PLK4 HETEROZYGOUS MICE. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC), ONE OF THE MOST COMMON CANCERS WORLD-WIDE OCCURS TWICE AS OFTEN IN MEN COMPARED TO WOMEN. PREDISPOSING CONDITIONS SUCH AS ALCOHOLISM, CHRONIC VIRAL HEPATITIS, AFLATOXIN B1 INGESTION, AND CIRRHOSIS ALL CONTRIBUTE TO THE DEVELOPMENT OF HCC. METHODS: WE USED A COMBINATION OF METHYLATION SPECIFIC PCR AND BISULFITE SEQUENCING, QREAL-TIME PCR (QPCR), AND WESTERN BLOT ANALYSIS TO EXAMINE EPIGENETIC CHANGES FOR THE POLO-LIKE KINASES (PLKS) DURING THE DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC) IN PLK4 HETEROZYGOUS MICE AND MURINE EMBRYONIC FIBROBLASTS (MEFS). RESULTS: HERE WE REPORT THAT THE PROMOTER METHYLATION OF PLK4 CPG ISLANDS INCREASES WITH AGE, WAS MORE PREVALENT IN MALES AND THAT PLK4 EPIGENETIC MODIFICATION AND SUBSEQUENT DOWNREGULATION OF EXPRESSION WAS ASSOCIATED WITH THE DEVELOPMENT OF HCC IN PLK4 MUTANT MICE. INTERESTINGLY, THE OPPOSITE OCCURS WITH ANOTHER PLK FAMILY MEMBER, PLK1 WHICH WAS TYPICALLY HYPERMETHYLATED IN NORMAL LIVER TISSUE BUT BECAME HYPOMETHYLATED AND UPREGULATED IN LIVER TUMOURS. FURTHERMORE, UPON ALCOHOL EXPOSURE MURINE EMBRYONIC FIBROBLASTS EXHIBITED INCREASED PLK4 HYPERMETHYLATION AND DOWNREGULATION ALONG WITH INCREASED CENTROSOME NUMBERS AND MULTINUCLEATION. CONCLUSIONS: THESE RESULTS SUGGEST THAT ABERRANT PLK METHYLATION IS CORRELATED WITH THE DEVELOPMENT OF HCC IN MICE. 2011 15 11 34 15Q12 VARIANTS, SPUTUM GENE PROMOTER HYPERMETHYLATION, AND LUNG CANCER RISK: A GWAS IN SMOKERS. BACKGROUND: LUNG CANCER IS THE LEADING CAUSE OF CANCER-RELATED MORTALITY WORLDWIDE. DETECTION OF PROMOTER HYPERMETHYLATION OF TUMOR SUPPRESSOR GENES IN EXFOLIATED CELLS FROM THE LUNG PROVIDES AN ASSESSMENT OF FIELD CANCERIZATION THAT IN TURN PREDICTS LUNG CANCER. THE IDENTIFICATION OF GENETIC DETERMINANTS FOR THIS VALIDATED CANCER BIOMARKER SHOULD PROVIDE NOVEL INSIGHTS INTO MECHANISMS UNDERLYING EPIGENETIC REPROGRAMMING DURING LUNG CARCINOGENESIS. METHODS: A GENOME-WIDE ASSOCIATION STUDY USING GENERALIZED ESTIMATING EQUATIONS AND LOGISTIC REGRESSION MODELS WAS CONDUCTED IN TWO GEOGRAPHICALLY INDEPENDENT SMOKER COHORTS TO IDENTIFY LOCI AFFECTING THE PROPENSITY FOR CANCER-RELATED GENE METHYLATION THAT WAS ASSESSED BY A 12-GENE PANEL INTERROGATED IN SPUTUM. ALL STATISTICAL TESTS WERE TWO-SIDED. RESULTS: TWO SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) AT 15Q12 (RS73371737 AND RS7179575) THAT DROVE GENE METHYLATION WERE DISCOVERED AND REPLICATED WITH RS73371737 REACHING GENOME-WIDE SIGNIFICANCE (P = 3.3X10(-8)). A HAPLOTYPE CARRYING RISK ALLELES FROM THE TWO 15Q12 SNPS CONFERRED 57% INCREASED RISK FOR GENE METHYLATION (P = 2.5X10(-9)). RS73371737 REDUCED GABRB3 EXPRESSION IN LUNG CELLS AND INCREASED RISK FOR SMOKING-INDUCED CHRONIC MUCOUS HYPERSECRETION. FURTHERMORE, SUBJECTS WITH VARIANT HOMOZYGOTE OF RS73371737 HAD A TWO-FOLD INCREASE IN RISK FOR LUNG CANCER (P = .0043). PATHWAY ANALYSIS IDENTIFIED DNA DOUBLE-STRAND BREAK REPAIR BY HOMOLOGOUS RECOMBINATION (DSBR-HR) AS A MAJOR PATHWAY AFFECTING SUSCEPTIBILITY FOR GENE METHYLATION THAT WAS VALIDATED BY MEASURING CHROMATID BREAKS IN LYMPHOCYTES CHALLENGED BY BLEOMYCIN. CONCLUSIONS: A FUNCTIONAL 15Q12 VARIANT WAS IDENTIFIED AS A RISK FACTOR FOR GENE METHYLATION AND LUNG CANCER. THE ASSOCIATIONS COULD BE MEDIATED BY GABAERGIC SIGNALING THAT DRIVES THE SMOKING-INDUCED MUCOUS CELL METAPLASIA. OUR FINDINGS ALSO SUBSTANTIATE DSBR-HR AS A CRITICAL PATHWAY DRIVING EPIGENETIC GENE SILENCING. 2015 16 3198 32 HDAC-LINKED "PROLIFERATIVE" MIRNA EXPRESSION PATTERN IN PANCREATIC NEUROENDOCRINE TUMORS. EPIGENETIC FACTORS ARE ESSENTIALLY INVOLVED IN CARCINOGENESIS, TUMOR PROMOTION, AND CHEMORESISTANCE. TWO EPIGENETIC KEY PLAYERS ARE MIRNAS AND HISTONE DEACETYLASES (HDACS). AS PREVIOUSLY SHOWN BY OWN THEORETICAL DATABANK ANALYSIS, THE CROSSTALK BETWEEN MIRNAS AND HDACS IS RELEVANT IN DIFFERENT HUMAN CHRONIC DISEASES AND CANCEROGENIC PATHWAYS. WE AIMED TO INVESTIGATE A POTENTIAL CONNECTION BETWEEN THE EXPRESSION OF A WELL-DEFINED SUBSET OF "PROLIFERATION-ASSOCIATED" MIRNAS AND THE EXPRESSION OF HDACS AS WELL AS CLINICAL PARAMETERS IN PANCREATIC NEUROENDOCRINE TUMORS (PNETS). MATERIALS AND METHODS: EXPRESSION LEVELS OF MIRNA132-3P, MIRNA145-5P, MIRNA183-5P, MIRNA34A-5P, AND MIRNA449A IN 57 PNETS RESECTED BETWEEN 1997 AND 2015 WERE MEASURED AND LINKED TO THE IMMUNOHISTOCHEMICAL EXPRESSION PATTERN OF MEMBERS OF THE FOUR HDAC CLASSES ON HUMAN TISSUE MICROARRAYS. ALL PNET CASES WERE CLINICALLY AND PATHOLOGICALLY CHARACTERIZED ACCORDING TO PUBLISHED GUIDELINES. CORRELATION ANALYSIS REVEALED A SIGNIFICANT ASSOCIATION BETWEEN EXPRESSION OF SPECIFIC MIRNAS AND TWO MEMBERS OF THE HDAC FAMILY (HDAC3 AND HDAC4). ADDITIONALLY, A LINKAGE BETWEEN MIRNA EXPRESSION AND CLINICO-PATHOLOGICAL PARAMETERS LIKE GRADING, TNM-STAGING, AND HORMONE ACTIVITY WAS FOUND. MOREOVER, OVERALL AND DISEASE-FREE SURVIVAL IS STATISTICALLY CORRELATED WITH THE EXPRESSION OF THE INVESTIGATED MIRNAS. OVERALL, WE DEMONSTRATED THAT SPECIFIC MIRNAS COULD BE LINKED TO HDAC EXPRESSION IN PNETS. ESPECIALLY MIRNA449A (ASSOCIATED WITH HDAC3/4) SEEMS TO PLAY AN IMPORTANT ROLE IN PNET PROLIFERATION AND COULD BE A POTENTIAL PROGNOSTIC FACTOR FOR POOR SURVIVAL. THESE FIRST DATA COULD HELP, TO IMPROVE OUR KNOWLEDGE OF THE COMPLEX INTERACTIONS OF THE EPIGENETIC DRIVERS IN PNETS FOR FURTHER THERAPEUTIC APPROACHES. 2018 17 3128 34 GIPC-REGULATED IGFBP-3 PROMOTES HSC MIGRATION IN VITRO AND PORTAL HYPERTENSION IN VIVO THROUGH A BETA1-INTEGRIN PATHWAY. BACKGROUND & AIMS: TRANSFORMING GROWTH FACTOR (TGF-BETA)-INDUCED ACTIVATION OF QUIESCENT HEPATIC STELLATE CELLS (HSCS) AND THEIR TRANSFORMATION TO MYOFIBROBLASTS IS A KEY EVENT IN LIVER FIBROSIS AND PORTAL HYPERTENSION. GIPC (ALSO REFERRED TO AS SYNECTIN) IS A DOWNSTREAM SIGNAL ACTIVATION MOLECULE OF TGF-BETA AND OTHER RECEPTORS. IN THIS STUDY, WE SOUGHT TO IDENTIFY NOVEL GENES TARGETED BY TGF-BETA AND GIPC AND ELUCIDATE IF AND HOW THEY MAY CONTRIBUTE TO LIVER FIBROSIS. METHODS: WE PERFORMED SEQUENTIAL MESSENGER RNA SEQUENCING ANALYSIS ON TGF-BETA-STIMULATED HSCS AND THEN ON TGF-BETA-STIMULATED HSCS IN THE PRESENCE AND ABSENCE OF GIPC ALSO REFERRED TO AS SYNECTIN (GIPC) KNOCKDOWN. INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-3 (IGFBP-3) TRANSPORT PROTEIN EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC. QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, TARGETED CHROMATIN IMMUNOPRECIPITATION, AND WESTERN BLOT ANALYSIS WERE DONE FOR FURTHER CONFIRMATION. RESULTS: IGFBP-3, AN INSULIN GROWTH FACTOR TRANSPORT PROTEIN, EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC, WHICH WAS CONFIRMED BY QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, AND WESTERN BLOT ANALYSIS. TARGETED CHROMATIN IMMUNOPRECIPITATION SHOWED THAT GIPC INCREASES THE HISTONE 3 LYSINE 27 (H3K27) ACETYLATION ACTIVATING MARK AND CONCURRENTLY DECREASES THE H3K27 INHIBITORY TRIMETHYLATION (H3K27M3) MARK, PROVIDING AN EPIGENETIC CORRELATE TO THE GENE REGULATION CHANGES. IN VIVO, GLOBAL KNOCKOUT OF IGFBP-3 MICE RESULTED IN ATTENUATION OF HSC ACTIVATION MARKERS AND ATTENUATION OF PORTAL PRESSURE IN RESPONSE TO CHRONIC LIVER INJURY MODELS. ANALYSIS OF SERUM LEVELS FROM CIRRHOTIC PATIENTS ALSO SHOWED AN IGFBP-3 INCREASE OF MORE THAN 2-FOLD COMPARED WITH HEALTHY CONTROLS. FINALLY, IN VITRO MECHANISM STUDIES SHOWED THAT IGFBP-3 PROMOTES HSC MIGRATION THROUGH INTEGRIN-DEPENDENT PHOSPHORYLATION OF PROTEIN KINASE B. CONCLUSIONS: TGF-BETA UP-REGULATES IGFBP-3 THROUGH GIPC, LEADING TO INCREASED HSC MIGRATION IN VITRO AND PROMOTES PORTAL HYPERTENSION IN VIVO. THESE STUDIES SUPPORT THE ROLE OF IGFBP-3 AS A POTENTIAL PATHOPHYSIOLOGIC TARGET OR BIOMARKER IN CHRONIC LIVER DISEASE. 2020 18 4221 36 METHYLATION AND SILENCING OF PROTEIN TYROSINE PHOSPHATASE RECEPTOR TYPE O IN CHRONIC LYMPHOCYTIC LEUKEMIA. PURPOSE: PREVIOUS STUDIES IN OUR LABORATORY HAVE SHOWN THE PROGRESSIVE METHYLATION AND SUPPRESSION OF THE GENE ENCODING PROTEIN TYROSINE PHOSPHATASE, PTPRO, IN THE LIVERS OF RATS FED A METHYL-DEFICIENT DIET THAT INDUCES HEPATOCARCINOGENESIS. SUBSEQUENTLY, WE OBSERVED THE METHYLATION OF PTPRO IN PRIMARY HUMAN LUNG TUMORS AND ALSO SHOWED ITS POTENTIAL TUMOR SUPPRESSOR CHARACTERISTICS. THE PRESENT STUDY WAS UNDERTAKEN TO INVESTIGATE WHETHER THE TRUNCATED FORM OF PTPRO (PTPROT), SPECIFICALLY EXPRESSED IN NAIVE B LYMPHOCYTES, WAS ALSO METHYLATED AND SUPPRESSED IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), A DISEASE GENERALLY AFFECTING B LYMPHOCYTES. EXPERIMENTAL DESIGN AND RESULTS: INITIAL SCREENING SHOWED THAT 60% OF THE 52 CLL SAMPLES ANALYZED USING METHYLATION-SPECIFIC PCR ASSAY WERE METHYLATED COMPARED WITH B LYMPHOCYTES FROM NORMAL INDIVIDUALS, WHICH WERE NOT METHYLATED. THE EXPRESSION OF PTPROT, AS MEASURED BY SEMIQUANTITATIVE REVERSE TRANSCRIPTION-PCR, INVERSELY CORRELATED WITH METHYLATION IN THE FEW SAMPLES TESTED. ANALYSIS OF ADDITIONAL SAMPLES (N = 50) BY COMBINED BISULFITE RESTRICTION ANALYSIS SHOWED THAT THE PTPRO CPG ISLAND WAS METHYLATED IN 82% OF PATIENTS WITH CLL COMPARED WITH B LYMPHOCYTES FROM NORMAL INDIVIDUALS. FURTHERMORE, OVERALL EXPRESSION OF PTPRO WAS REDUCED IN CLL RELATIVE TO NORMAL LYMPHOCYTES. THE PTPRO GENE WAS ALSO SUPPRESSED BY METHYLATION IN THE CLL CELL LINE WAC3CD5, WHERE IT COULD BE REACTIVATED UPON TREATMENT WITH THE DNA HYPOMETHYLATING AGENT 5-AZAC. ECTOPIC EXPRESSION OF PTPROT IN A NONEXPRESSING CELL LINE INCREASED GROWTH INHIBITION WITH FLUDARABINE TREATMENT, A THERAPY COMMONLY USED FOR CLL. CONCLUSION: THIS STUDY REVEALS THE POTENTIAL ROLE OF PTPRO METHYLATION AND SILENCING IN CLL TUMORIGENESIS AND ALSO PROVIDES A NOVEL MOLECULAR TARGET IN THE EPIGENETIC THERAPY. 2007 19 1067 39 CLINICAL UTILITY OF PDSS2 EXPRESSION TO STRATIFY PATIENTS AT RISK FOR RECURRENCE OF HEPATOCELLULAR CARCINOMA. IDENTIFICATION OF NOVEL GENETIC AND EPIGENETIC ALTERATIONS IS REQUIRED FOR OPTIMAL STRATIFICATION OF PATIENTS WITH HEPATOCELLULAR CARCINOMA (HCC) AT RISK FOR RECURRENCE AND ADVERSE PROGNOSIS. COENZYME Q10 (COQ10), WHICH MEDIATES APOPTOSIS, IS SYNTHESIZED BY PRENYL DIPHOSPHATE SYNTHASE SUBUNIT 2 (PDSS2). IN THE PRESENT STUDY WE EVALUATED THE CLINICAL SIGNIFICANCE AND REGULATORY MECHANISMS OF PDSS2 EXPRESSION IN HCC. PDSS2 EXPRESSION LEVELS AND THOSE OF GENES ENCODING POTENTIALLY INTERACTING PROTEINS AS WELL AS THE METHYLATION STATUS OF THE PDSS2 PROMOTER REGION WERE ANALYZED IN HCC CELL LINES. PDSS2 MRNA LEVELS IN 151 PAIRS OF RESECTED SPECIMENS WERE DETERMINED TO EVALUATE THE ASSOCIATION OF PDSS2 EXPRESSION AND CLINICOPATHOLOGICAL FACTORS. THE EXPRESSION AND DISTRIBUTION OF PDSS2 WERE DETERMINED USING IMMUNOHISTOCHEMISTRY. PDSS2 MRNA EXPRESSION WAS DECREASED IN SIX OF NINE HCC CELL LINES AND SIGNIFICANTLY CORRELATED WITH THOSE OF HEPATOCYTE NUCLEAR FACTOR 4ALPHA. PDSS2 TRANSCRIPTION IN HCC CELLS WITH DECREASED PDSS2 EXPRESSION ACCOMPANYING HYPERMETHYLATION WAS REACTIVATED AFTER TREATING THESE CELLS WITH A METHYLATION INHIBITOR. MEAN EXPRESSION LEVELS OF PDSS2 MRNA RELATIVE TO THAT OF UNINVOLVED LIVER DIMINISHED GRADUALLY IN THE ORDER OF CHRONIC HEPATITIS TO CIRRHOSIS, AND EACH WAS SIGNIFICANTLY HIGHER THAN THOSE OF HCCS. PDSS2 AND PDSS2 MRNA LEVELS WERE CONSISTENT. DECREASED PDSS2 MRNA LEVELS WERE DETECTED IN HCC TISSUES OF 56 PATIENTS, CORRELATED WITH SHORTER DISEASE-SPECIFIC SURVIVAL, AND WAS IDENTIFIED AS AN INDEPENDENT PROGNOSTIC FACTOR. PDSS2 IS A PUTATIVE TUMOR SUPPRESSOR, AND PROMOTER HYPERMETHYLATION IS A KEY REGULATORY MECHANISM IN HCC. DECREASED LEVELS OF PDSS2 MRNA EXPRESSION MAY REPRESENT A NOVEL BIOMARKER OF HCC. 2014 20 546 29 ATTENUATED EXPRESSION OF SLCO2A1 CAUSED BY DNA METHYLATION IN PEDIATRIC INFLAMMATORY BOWEL DISEASE. BACKGROUND: SLCO2A1 ENCODES A PROSTAGLANDIN (PG) TRANSPORTER, AND AUTOSOMAL RECESSIVE PATHOGENIC VARIANTS OF THIS GENE CAUSE CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1. IT IS UNCLEAR WHETHER A HETEROZYGOUS PATHOGENIC VARIANT OF SLCO2A1 HAS A ROLE IN THE PATHOGENESIS OF OTHER TYPES OF INFLAMMATORY BOWEL DISEASE (IBD). IN THIS STUDY, WE INVESTIGATED THE POSSIBLE INVOLVEMENT OF A LOCAL EPIGENETIC ALTERATION IN SLCO2A1 IN PATIENTS WITH A HETEROZYGOUS PATHOGENIC VARIANT. METHODS: WE CONDUCTED WHOLE-EXOME SEQUENCING OF SAMPLES FROM 2 SISTERS WITH SUSPECTED MONOGENIC IBD. IN ADDITION, WE PERFORMED BISULFITE SEQUENCING USING DNA EXTRACTED FROM THEIR SMALL AND LARGE INTESTINE SAMPLES TO EXPLORE EPIGENETIC ALTERATIONS. RESULTS: A HETEROZYGOUS SPLICING SITE VARIANT, SLCO2A1:C.940 + 1G > A, WAS DETECTED IN BOTH PATIENTS. TO EXPLORE THE POSSIBLE INVOLVEMENT OF EPIGENETIC ALTERATIONS, WE ANALYZED PROTEIN AND MESSENGER RNA EXPRESSION OF SLCO2A1, AND OBSERVED ATTENUATED SLCO2A1 EXPRESSION IN THE INFLAMED LESIONS OF THESE PATIENTS COMPARED WITH THAT IN THE CONTROL INDIVIDUALS. FURTHERMORE, BISULFITE SEQUENCING INDICATED DENSE METHYLATION IN THE PROMOTER REGION OF SLCO2A1 ONLY IN THE INFLAMED LESIONS OF BOTH PATIENTS. THE URINARY PG METABOLITE LEVELS IN THESE PATIENTS WERE COMPARABLE TO THOSE IN PATIENTS WITH CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1 AND HIGHER THAN THOSE IN THE CONTROL INDIVIDUALS. WE FOUND CONSIDERABLY HIGHER LEVELS OF THE METABOLITES IN PATIENT 1, WHO SHOWED MORE SEVERE SYMPTOMS THAN PATIENT 2. CONCLUSIONS: LOCAL DNA METHYLATION ATTENUATED SLCO2A1 EXPRESSION, WHICH MAY EVOKE LOCAL INFLAMMATION OF THE MUCOSA BY THE UNINCORPORATED PG. THESE FINDINGS MAY IMPROVE OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS UNDERLYING IBD DEVELOPMENT. 2023