1 152 116 ABERRANT METHYLATION OF DAPK IN LONG-STANDING ULCERATIVE COLITIS AND ULCERATIVE COLITIS-ASSOCIATED CARCINOMA. DEATH-ASSOCIATED PROTEIN KINASE (DAPK) HAS PRO-APOPTOTIC FUNCTIONS AND PARTICIPATES IN VARIOUS APOPTOTIC SYSTEMS. DAPK ACTS AS A TUMOR SUPPRESSOR, AND ITS INACTIVATION BY PROMOTER HYPERMETHYLATION HAS BEEN FREQUENTLY OBSERVED IN VARIOUS HUMAN CANCERS. AS ALTERATIONS OF PRO-APOPTOTIC GENES MIGHT CAUSE INSTABILITY IN THE BALANCE OF CELL-TURNOVER DURING CHRONIC INFLAMMATORY PROCESSES, EPIGENETIC SILENCING OF DAPK MIGHT BE INVOLVED IN THE CARCINOGENESIS OF ULCERATIVE COLITIS-ASSOCIATED CARCINOMA (UCC). TO EVALUATE THE ROLE OF DAPK IN THE INFLAMMATION-DRIVEN CARCINOGENESIS OF ULCERATIVE COLITIS (UC), WE ANALYZED PROMOTER HYPERMETHYLATION AND PROTEIN EXPRESSION OF DAPK USING METHYLATION-SPECIFIC PCR AND IMMUNOHISTOCHEMISTRY IN 43 UCCS AND PAIRED UC-BACKGROUND MUCOSA, AS WELL AS IN UC-BACKGROUND MUCOSA OF 50 PATIENTS WITHOUT UCC. THE FREQUENCY OF METHYLATION OF DAPK IN UCCS WAS LOW (27.6%) COMPARED TO OVERALL NON-NEOPLASTIC UC-BACKGROUND MUCOSA (48.3%; P=0.02) AND SPORADIC COLORECTAL CARCINOMA (57.4%, P=0.019). THE DIFFERENCE IN THE METHYLATION FREQUENCY IN UC-BACKGROUND MUCOSA IN PATIENTS WITHOUT UCC (54.2%), COMPARED TO THOSE WITH UCC (40.0%), WAS NOT SIGNIFICANT (P=0.141). PROMOTER METHYLATION CORRELATED SIGNIFICANTLY WITH DECREASED DAPK PROTEIN EXPRESSION (P<0.001) AND SEVERITY OF INFLAMMATORY ACTIVITY (P=0.024). IN UNMETHYLATED UC-BACKGROUND MUCOSA, DAPK PROTEIN EXPRESSION INCREASED WITH ACTIVITY OF UC-ASSOCIATED INFLAMMATION, SUGGESTING A PROTECTIVE ROLE OF THE PRO-APOPTOTIC DAPK DURING THE CHRONIC INFLAMMATORY PROCESS OF UC. THUS, INACTIVATION OF DAPK BY PROMOTER HYPERMETHYLATION MIGHT BE CRUCIAL FOR ACCUMULATION OF DNA DAMAGE IN INFLAMED MUCOSA OF UC, AND MIGHT THEREFORE CONTRIBUTE TO THE INITIATION OF THE NEOPLASTIC PROCESS AND DEVELOPMENT OF UC-ASSOCIATED CARCINOMA. 2010 2 2453 37 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 4232 38 METHYLATION OF RUNX3 IN VARIOUS TYPES OF HUMAN CANCERS AND PREMALIGNANT STAGES OF GASTRIC CARCINOMA. ACCUMULATING EVIDENCE HAS IDENTIFIED A MECHANISM POTENTIALLY RESPONSIBLE FOR THE INACTIVATION OF TUMOR SUPPRESSOR GENES, NAMELY TRANSCRIPTIONAL SILENCING BY ABERRANT METHYLATION OF CPG ISLANDS. A PREVIOUS STUDY HAS SHOWN THE LOSS OF RUNX3 EXPRESSION, DUE TO ABERRANT METHYLATION OF ITS CPG ISLAND, IN GASTRIC CANCER CELL LINES, SUGGESTING THAT RUNX3 IS A TARGET FOR EPIGENETIC GENE SILENCING IN GASTRIC CARCINOGENESIS. HOWEVER, THERE ARE LIMITED DATA ON THE METHYLATION STATUS OF RUNX3 IN THE NEOPLASTIC AND NON-NEOPLASTIC TISSUES IN VARIOUS TYPES OF HUMAN CANCERS, INCLUDING GASTRIC CANCER. HERE, WE REPORT THAT 60% OF GASTRIC CANCER CELL LINES AND 64% OF PRIMARY GASTRIC CARCINOMAS (N=75) WERE METHYLATED AT THE RUNX3 CPG ISLAND. RUNX3 METHYLATION WAS ALSO DETECTED IN HEPATOCELLULAR CARCINOMAS (73%, N=48), LARYNX CANCERS (62%, N=37), LUNG CANCERS (46%, N=24), BREAST CANCERS (25%, N=25), PROSTATE CANCERS (23%, N=44), ENDOMETRIAL CANCERS (12.5%, N=24), COLON CANCERS (4.9%, N=61) AND UTERINE CERVICAL CANCERS (2.5%, N=40), SHOWING THAT RUNX3 METHYLATION IS NOT RESTRICTED TO GASTRIC CANCER. INTERESTINGLY, THE RUNX3 METHYLATION WAS ESPECIALLY FREQUENT IN TUMORS FROM TISSUES OF A FOREGUT DERIVATIVE, THAT IS, THE STOMACH, LIVER, LARYNX AND LUNG. NEXT, THE METHYLATION STATUS OF RUNX3 IN VARIOUS NON-NEOPLASTIC TISSUES WAS EXAMINED, INCLUDING THE PREMALIGNANT LESIONS OF GASTRIC CARCINOMAS. THE RUNX3 METHYLATION WAS FOUND IN 8.1% OF CHRONIC GASTRITIS (N=99), 28.1% OF INTESTINAL METAPLASIA (N=32), 27.3% OF GASTRIC ADENOMAS (N=77) AND 64% OF GASTRIC CARCINOMAS (N=75), BUT NOT IN CHRONIC HEPATITIS B, NORMAL PROSTATE AND COLON MUCOSA, EVEN THOUGH IN CASES OF CHRONIC HEPATITIS, THE METHYLATION FREQUENCY OF ITS NEOPLASTIC TISSUES WAS VERY HIGH. IN CONCLUSION, RUNX3 METHYLATION IS FREQUENTLY FOUND IN HUMAN CANCERS, INCLUDING GASTRIC CANCER, AND IS MOSTLY CANCER SPECIFIC, WITH THE EXCEPTION OF THE STOMACH, AND THUS, MIGHT BE USEFUL AS A POTENTIAL DIAGNOSTIC BIOMARKER OF CANCER. 2004 4 1966 38 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 3439 31 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 6 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 7 2637 28 EPIGENOME-WIDE STUDY IDENTIFIES EPIGENETIC OUTLIERS IN NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. NONGENETIC PREDISPOSITION TO COLORECTAL CANCER CONTINUES TO BE DIFFICULT TO MEASURE PRECISELY, HAMPERING EFFORTS IN TARGETED PREVENTION AND SCREENING. EPIGENETIC CHANGES IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER CAN SERVE AS A TOOL IN PREDICTING COLORECTAL CANCER OUTCOMES. WE IDENTIFIED EPIGENETIC CHANGES AFFECTING THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER. DNA METHYLATION PROFILING ON NORMAL COLON MUCOSA FROM 77 PATIENTS WITH COLORECTAL CANCER AND 68 CONTROLS IDENTIFIED A DISTINCT SUBGROUP OF NORMALLY-APPEARING MUCOSA WITH MARKEDLY DISRUPTED DNA METHYLATION AT A LARGE NUMBER OF CPGS, TERMED AS "OUTLIER METHYLATION PHENOTYPE" (OMP) AND ARE PRESENT IN 15 OF 77 PATIENTS WITH CANCER VERSUS 0 OF 68 CONTROLS (P < 0.001). SIMILAR FINDINGS WERE ALSO SEEN IN PUBLICLY AVAILABLE DATASETS. COMPARISON OF NORMAL COLON MUCOSA TRANSCRIPTION PROFILES OF PATIENTS WITH OMP CANCER WITH THOSE OF PATIENTS WITH NON-OMP CANCER INDICATES GENES WHOSE PROMOTERS ARE HYPERMETHYLATED IN THE OMP PATIENTS ARE ALSO TRANSCRIPTIONALLY DOWNREGULATED, AND THAT MANY OF THE GENES MOST AFFECTED ARE INVOLVED IN INTERACTIONS BETWEEN EPITHELIAL CELLS, THE MUCUS LAYER, AND THE MICROBIOME. ANALYSIS OF 16S RRNA PROFILES SUGGESTS THAT NORMAL COLON MUCOSA OF OMPS ARE ENRICHED IN BACTERIAL GENERA ASSOCIATED WITH COLORECTAL CANCER RISK, ADVANCED TUMOR STAGE, CHRONIC INTESTINAL INFLAMMATION, MALIGNANT TRANSFORMATION, NOSOCOMIAL INFECTIONS, AND KRAS MUTATIONS. IN CONCLUSION, OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. PROSPECTIVE STUDIES ARE NEEDED TO DETERMINE WHETHER OMP COULD SERVE AS A BIOMARKER FOR AN ELEVATED EPIGENETIC RISK FOR COLORECTAL CANCER DEVELOPMENT. PREVENTION RELEVANCE: OUR STUDY IDENTIFIES AN EPIGENETICALLY DISTINCT OMP GROUP IN THE NORMAL MUCOSA OF PATIENTS WITH COLORECTAL CANCER THAT IS CHARACTERIZED BY A DISRUPTED METHYLOME, ALTERED GENE EXPRESSION, AND MICROBIAL DYSBIOSIS. IDENTIFICATION OF OMPS IN HEALTHY CONTROLS AND PATIENTS WITH COLORECTAL CANCER WILL LEAD TO PREVENTION AND BETTER PROGNOSIS, RESPECTIVELY. 2022 8 155 28 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 9 3125 21 GHSR DNA HYPERMETHYLATION IS A COMMON EPIGENETIC ALTERATION OF HIGH DIAGNOSTIC VALUE IN A BROAD SPECTRUM OF CANCERS. IDENTIFICATION OF A SINGLE MOLECULAR TRAIT THAT IS DETERMINANT OF COMMON MALIGNANCIES MAY SERVE AS A POWERFUL DIAGNOSTIC SUPPLEMENT TO CANCER TYPE-SPECIFIC MARKERS. HERE, WE REPORT A DNA METHYLATION MARK THAT IS CHARACTERISTIC OF SEVEN STUDIED MALIGNANCIES, NAMELY CANCERS OF LUNG, BREAST, PROSTATE, PANCREAS, COLORECTUM, GLIOBLASTOMA AND B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) (N = 137). THIS MARK WAS DEFINED BY SUBSTANTIAL HYPERMETHYLATION AT THE PROMOTER AND FIRST EXON OF GROWTH HORMONE SECRETAGOUGE RECEPTOR (GHSR) THROUGH BISULFITE PYROSEQUENCING. THE DEGREE OF ABERRANT METHYLATION WAS CAPABLE OF ACCURATE DISCRIMINATION BETWEEN CANCER AND CONTROL SAMPLES. THE HIGHEST SENSITIVITY AND SPECIFICITY OF CANCER DETECTION WAS ACHIEVED FOR CANCERS OF PANCREAS, LUNG, BREAST AND CLL YIELDING THE AREA UNDER THE CURVE (AUC) VALUES OF 1.0000, 0.9952, 0.9800 AND 0.9400, RESPECTIVELY. NARROWING TO A SINGLE CPG SITE WITHIN THE GENE'S PROMOTER OR FOUR CONSECUTIVE CPG UNITS OF THE HIGHEST METHYLATION LEVELS WITHIN THE FIRST EXON IMPROVED THE DETECTION POWER. GHSR HYPERMETHYLATION WAS DETECTED ALREADY AT THE EARLY STAGE TUMORS. THE ACCURATE PERFORMANCE OF THIS MARKER WAS FURTHER REPLICATED IN AN INDEPENDENT SET OF PANCREATIC CANCER AND CONTROL SAMPLES (N = 78). THESE FINDINGS SUPPORT THE CANDIDATURE OF GHSR METHYLATION AS A HIGHLY ACCURATE PAN-CANCER MARKER. 2015 10 1011 21 CIGARETTE SMOKE CONDENSATE INDUCES DIFFERENTIAL EXPRESSION AND PROMOTER METHYLATION PROFILES OF CRITICAL GENES INVOLVED IN LUNG CANCER IN NL-20 LUNG CELLS IN VITRO: SHORT-TERM AND CHRONIC EXPOSURE. ESTABLISHING EARLY DIAGNOSTIC MARKERS OF HARM IS CRITICAL FOR EFFECTIVE PREVENTION PROGRAMS AND REGULATION OF TOBACCO PRODUCTS. THIS STUDY EXAMINED EFFECTS OF CIGARETTE SMOKE CONDENSATE (CSC) ON EXPRESSION AND PROMOTER METHYLATION PROFILE OF CRITICAL GENES (DAPK, ECAD, MGMT, AND RASSF1A) INVOLVED IN LUNG CANCER DEVELOPMENT IN DIFFERENT HUMAN LUNG CELL LINES. NL-20 CELLS WERE TREATED WITH 0.1-100 MUG/ML OF CSC FOR 24 TO 72 HRS FOR SHORT-TERM EXPOSURES. DAPK EXPRESSION OR METHYLATION STATUS WAS NOT SIGNIFICANTLY AFFECTED. HOWEVER, CSC TREATMENT RESULTED IN CHANGES IN EXPRESSION AND PROMOTER METHYLATION PROFILE OF ECAD, MGMT, AND RASSF1A. FOR CHRONIC STUDIES, CELLS WERE EXPOSED TO 1 OR 10 MUG/ML CSC UP TO 28 DAYS. CELLS SHOWED MORPHOLOGICAL CHANGES ASSOCIATED WITH TRANSFORMATION AND CHANGES IN INVASION CAPACITIES AND GLOBAL METHYLATION STATUS. THIS STUDY PROVIDES CRITICAL DATA SUGGESTING THAT EPIGENETIC CHANGES COULD SERVE AS AN EARLY BIOMARKER OF HARM DUE TO EXPOSURE TO CIGARETTE SMOKE. 2013 11 494 25 ASSESSMENT OF PROMOTER METHYLATION IDENTIFIES PTCH AS A PUTATIVE TUMOR-SUPPRESSOR GENE IN HUMAN CLL. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF NEOPLASTIC LYMPHOCYTES, INDICATING DISRUPTION OF APOPTOSIS. PATIENTS AND METHODS: DIFFERENTIAL METHYLATION HYBRIDIZATION ANALYSIS WAS PERFORMED TO IDENTIFY NOVEL TARGET GENES SILENCED BY CPG ISLAND METHYLATION IN PATIENTS WITH CLL. RESULTS: PATCHED (PTCH), A TUMOR-SUPPRESSOR GENE, WAS FOUND TO BE FREQUENTLY METHYLATED IN CLL SAMPLES COMPARED TO SAMPLES DERIVED FROM HEALTHY INDIVIDUALS. DE NOVO METHYLATION OF A CPG ISLAND REGION LOCATED UPSTREAM OF PTCH EXON 1 WAS CONFIRMED BY PYROSEQUENCING IN 17/37 (46%) OF PERIPHERAL BLOOD MONONUCLEAR CELLS OF PATIENTS WITH CLL, BUT IN NONE ISOLATED FROM SEVEN HEALTHY INDIVIDUALS. NO ASSOCIATION WAS FOUND BETWEEN PTCH HYPERMETHYLATION AND CURRENTLY USED PROGNOSTIC CLL FACTORS. CONCLUSION: OUR INVESTIGATION SUGGESTS THAT EPIGENETIC SILENCING OF PTCH IS A MECHANISM CONTRIBUTING TO CLL TUMORIGENESIS. 2016 12 3298 32 HIGH-DEFINITION CPG METHYLATION OF NOVEL GENES IN GASTRIC CARCINOGENESIS IDENTIFIED BY NEXT-GENERATION SEQUENCING. GASTRIC CANCERS ARE THE MOST FREQUENT GASTRIC MALIGNANCY AND USUALLY ARISE IN THE SEQUENCE OF HELICOBACTER PYLORI-ASSOCIATED CHRONIC GASTRITIS. CPG METHYLATION IS A CENTRAL MECHANISM OF EPIGENETIC GENE REGULATION AFFECTING CANCER-RELATED GENES, AND OCCURS EARLY IN GASTRIC CARCINOGENESIS. DNA SAMPLES FROM NON-METAPLASTIC GASTRIC MUCOSA WITH VARIABLE LEVELS OF GASTRITIS (NON-METAPLASTIC MUCOSA), INTESTINAL METAPLASIA, OR GASTRIC CANCER WERE SCREENED WITH METHYLATION ARRAYS FOR CPG METHYLATION OF CANCER-RELATED GENES AND 30 GENE TARGETS WERE FURTHER CHARACTERIZED BY HIGH-DEFINITION BISULFITE NEXT-GENERATION SEQUENCING. IN ADDITION, DATA FROM THE CANCER GENOME ATLAS WERE ANALYZED FOR CORRELATION OF METHYLATION WITH GENE EXPRESSION. OVERALL, 13 GENES HAD SIGNIFICANTLY INCREASED CPG METHYLATION IN GASTRIC CANCER VS NON-METAPLASTIC MUCOSA (BRINP1, CDH11, CHFR, EPHA5, EPHA7, FGF2, FLI1, GALR1, HS3ST2, PDGFRA, SEZ6L, SGCE, AND SNRPN). FURTHER, MOST OF THESE GENES HAD CORRESPONDING REDUCED EXPRESSION LEVELS IN GASTRIC CANCER COMPARED WITH INTESTINAL METAPLASIA, INCLUDING NOVEL HYPERMETHYLATED GENES IN GASTRIC CANCER (FLI1, GALR1, SGCE, AND SNRPN), SUGGESTING THAT THEY MAY REGULATE NEOPLASTIC TRANSFORMATION FROM NON-MALIGNANT INTESTINAL METAPLASIA TO CANCER. OUR DATA SUGGEST A TUMOR-SUPPRESSOR ROLE FOR FLI1 IN GASTRIC CANCER, CONSISTENT WITH RECENTLY REPORTED DATA IN BREAST CANCER. FOR THE GENES WITH STRONGEST METHYLATION/EXPRESSION CORRELATION, NAMELY FLI1, THE EXPRESSION WAS LOWEST IN MICROSATELLITE-UNSTABLE TUMORS COMPARED WITH OTHER GASTRIC CANCER MOLECULAR SUBTYPES. IMPORTANTLY, REDUCED EXPRESSION OF HYPERMETHYLATED BRINP1 AND SGCE WAS SIGNIFICANTLY ASSOCIATED WITH FAVORABLE SURVIVAL IN GASTRIC CANCER. IN SUMMARY, WE REPORT NOVEL METHYLATION GENE TARGETS THAT MAY HAVE FUNCTIONAL ROLES IN DISCRETE STAGES OF GASTRIC CARCINOGENESIS AND MAY SERVE AS BIOMARKERS FOR DIAGNOSIS AND PROGNOSIS OF GASTRIC CANCER. 2016 13 2037 29 EPIGENETIC CHANGES OF TIMP-3, GSTP-1 AND 14-3-3 SIGMA GENES AS INDICATION OF STATUS OF CHRONIC INFLAMMATION AND CANCER. OBJECTIVES: THIS STUDY AIMED TO COMPARE THE EPIGENETIC CHANGES VIA HYPERMETHYLATION STATUS OF TIMP-3, GSTP-1 AND 14-3-3SIGMA GENES, BETWEEN HEALTHY SUBJECTS AND PATIENTS WITH REVERSIBLE CHRONIC INFLAMMATORY DISEASE, AND BETWEEN HEALTHY SUBJECTS AND PATIENTS WITH IRREVERSIBLE MALIGNANT DISEASE, TO HIGHLIGHT THE GENETIC CHANGES THAT OCCUR IN THE PROGRESSION FROM AN INFLAMMATORY CONDITION TO IRREVERSIBLE GENETIC CHANGES COMMONLY OBSERVED IN CANCER PATIENTS. METHODS: DNA WAS EXTRACTED FROM THE BLOOD OF 680 HEALTHY SUBJECTS, AND TISSUES AND BLOOD OF 110 PATIENTS WITH CHRONIC INFLAMMATION DISEASE OF THE GUMS, AS WELL AS NEOPLASTIC TISSUES OF 108 BREAST CANCER PATIENTS. METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) FOR TIMP-3, GSTP-1 AND 14-3-3SIGMA WAS PERFORMED, AND HYPERMETHYLATION STATUS WAS ANALYZED AND COMPARED BETWEEN THE 3 GROUPS. RESULTS: THE HYPERMETHYLATION FREQUENCIES OF TIMP-3 AND GSTP-1 OF REVERSIBLE CHRONIC INFLAMMATORY GUM DISEASE AND THE CONTROL GROUP WERE SIMILAR, BUT BOTH WERE SIGNIFICANTLY LOWER THAN THOSE FOR MALIGNANT DISEASE PATIENTS (P<0.0001). THE METHYLATION FREQUENCY OF 14-3-3SIGMA IN CHRONIC INFLAMMATORY GUM DISEASE WAS HIGHER THAN IN THE CANCER AND CONTROL GROUPS (P<0.0001). THE METHYLATION OF CPG ISLANDS IN TIMP-3 AND GSTP-1 IN CHRONIC INFLAMMATION PATIENTS OCCURRED AS FREQUENTLY AS IN THE CONTROL GROUP, BUT LESS FREQUENTLY THAN IN BREAST CANCER PATIENTS. HOWEVER, THE EPIGENETIC SILENCING OF 14-3-3SIGMA OCCURRED MORE FREQUENTLY IN THE CHRONIC INFLAMMATION GROUP THAN IN CANCER PATIENTS AND HEALTHY CONTROLS. CONCLUSIONS: THE EPIGENETIC SILENCING OF 14-3-3SIGMA MIGHT BE ESSENTIAL FOR CHRONIC INFLAMMATORY GUM DISEASE. THE EPIGENETIC CHANGES PRESENTED IN CHRONIC INFLAMMATION PATIENTS MIGHT DEMONSTRATE AN IRREVERSIBLE DESTRUCTION IN THE TISSUES OR ORGANS SIMILAR TO CANCER. 2014 14 4220 28 METHYLATED CYSTEINE DIOXYGENASE-1 GENE PROMOTER IN THE SERUM IS A POTENTIAL BIOMARKER FOR HEPATITIS B VIRUS-RELATED HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE THIRD LEADING CAUSE OF CANCER-RELATED MORTALITY WORLDWIDE. EPIGENETIC ANALYSIS HAS ATTRACTED INCREASING ATTENTION IN THE MOLECULAR DIAGNOSIS OF HCC. CYSTEINE DIOXYGENASE 1 (CDO1) IS A KEY ENZYME IN THE TAURINE BIOSYNTHETIC PATHWAY AND CONVERTS CYSTEINE TO CYSTEINE SULFINATE. THE CDO1 GENE IS A TUMOR SUPPRESSOR GENE AND IS USUALLY SILENCED BY THE METHYLATION OF ITS PROMOTER IN CARCINOGENESIS. IN THIS STUDY, WE EVALUATED WHETHER THE METHYLATION STATUS OF CDO1 GENE PROMOTER IS OF DIAGNOSTIC VALUE FOR HEPATITIS B VIRUS (HBV)-RELATED HCC. THE CDO1 PROMOTER METHYLATION STATUS WAS DETERMINED IN SERUM SAMPLES USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) IN A COHORT OF 123 PATIENTS WITH HBV-RELATED HCC, 28 WITH LIVER CIRRHOSIS (LC), 29 WITH CHRONIC HEPATITIS B (CHB) AND 20 HEALTHY CONTROLS. THE FREQUENCY OF THE CDO1 PROMOTER METHYLATION IN HBV-RELATED HCC (42.3%) WAS SIGNIFICANTLY HIGHER THAN THAT IN LC (14.3%), CHB (6.9%) AND HEALTHY CONTROLS (0%) (P = 0.006; P < 0.0001; P < 0.0001; RESPECTIVELY). FURTHERMORE, IN HCC PATIENTS, THE FREQUENCY OF CDO1 PROMOTER METHYLATION WAS HIGHER IN ADVANCED STAGES (III-IV) (53%) THAN THE EARLY STAGES (I-II) (20%) (P = 0.001). EVALUATION OF THE CDO1 PROMOTER METHYLATION STATUS IN SERUM, IN COMBINATION WITH AFP (> 20 NG/ML), SIGNIFICANTLY IMPROVED THE DIAGNOSTIC VALUE, WITH SENSITIVITY AND SPECIFICITY OF 82.9% AND 75.4%, RESPECTIVELY IN DISTINGUISHING HCC FROM LC AND CHB. IN CONCLUSION, METHYLATION STATUS OF SERUM CDO1 GENE PROMOTER MAY BE HELPFUL IN THE DIAGNOSIS OF HCC AND THE ESTIMATION OF THE HCC STAGES. 2014 15 2327 28 EPIGENETIC REGULATION OF HUMAN CANCER/TESTIS ANTIGEN GENE, HAGE, IN CHRONIC MYELOID LEUKEMIA. BACKGROUND AND OBJECTIVES: CANCER TESTIS ANTIGENS (CTA) PROVIDE ATTRACTIVE TARGETS FOR CANCER-SPECIFIC IMMUNOTHERAPY. ALTHOUGH CTA GENES ARE EXPRESSED IN SOME NORMAL TISSUES, SUCH AS THE TESTIS, THIS IMMUNOLOGICALLY PROTECTED SITE LACKS MHC I EXPRESSION AND AS SUCH, DOES NOT PRESENT SELF ANTIGENS TO T CELLS. TO DATE, CTA GENES HAVE BEEN SHOWN TO BE EXPRESSED IN A RANGE OF SOLID TUMORS VIA DEMETHYLATION OF THEIR PROMOTER CPG ISLANDS, BUT RARELY IN CHRONIC MYELOID LEUKEMIA (CML) OR OTHER HEMATOLOGIC MALIGNANCIES. DESIGN AND METHODS: IN THIS STUDY, THE METHYLATION STATUS OF THE HAGE CTA GENE PROMOTER WAS ANALYZED BY QUANTITATIVE METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) AND SEQUENCING IN FOUR PHILADELPHIA-POSITIVE CELL LINES (TCC-S, K562, KU812 AND KYO-1) AND IN CML SAMPLES TAKEN FROM PATIENTS IN CHRONIC PHASE (CP N=215) OR BLAST CRISIS (BC N=47). HAGE EXPRESSION WAS ASSESSED BY QUANTITATIVE REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION. RESULTS: THE TCC-S CELL LINE SHOWED DEMETHYLATION OF HAGE THAT WAS ASSOCIATED WITH OVER-EXPRESSION OF THIS GENE. HAGE HYPOMETHYLATION WAS SIGNIFICANTLY MORE FREQUENT IN BC (46%) THAN IN CP (22%) (P=0.01) AND WAS CORRELATED WITH HIGH EXPRESSION LEVELS OF HAGE TRANSCRIPTS (P<0.0001). OF NOTE, IN CP-CML, EXTENSIVE HAGE HYPOMETHYLATION WAS ASSOCIATED WITH POORER PROGNOSIS IN TERMS OF CYTOGENETIC RESPONSE TO INTERFERON (P=0.01) OR IMATINIB (P=0.01), MOLECULAR RESPONSE TO IMATINIB (P=0.003) AND PROGRESSION-FREE SURVIVAL (P=0.05). INTERPRETATIONS AND CONCLUSION: THE METHYLATION STATUS OF THE HAGE PROMOTER DIRECTLY CORRELATES WITH ITS EXPRESSION IN BOTH CML CELL LINES AND PATIENTS AND IS ASSOCIATED WITH ADVANCED DISEASE AND POOR OUTCOME. 2007 16 499 34 ASSOCIATION BETWEEN HMLH1 HYPERMETHYLATION AND JC VIRUS (JCV) INFECTION IN HUMAN COLORECTAL CANCER (CRC). INCORPORATION OF VIRAL DNA MAY INTERFERE WITH THE NORMAL SEQUENCE OF HUMAN DNA BASES ON THE GENETIC LEVEL OR CAUSE SECONDARY EPIGENETIC CHANGES SUCH AS GENE PROMOTER METHYLATION OR HISTONE ACETYLATION. COLORECTAL CANCER (CRC) IS THE SECOND LEADING CAUSE OF CANCER MORTALITY IN THE USA. CHROMOSOMAL INSTABILITY (CIN) WAS ESTABLISHED AS THE KEY MECHANISM IN CANCER DEVELOPMENT. LATER, IT WAS FOUND THAT CRC RESULTS NOT ONLY FROM THE PROGRESSIVE ACCUMULATION OF GENETIC ALTERATIONS BUT ALSO FROM EPIGENETIC CHANGES. JC VIRUS (JCV) IS A CANDIDATE ETIOLOGIC FACTOR IN SPORADIC CRC. IT MAY ACT BY STABILIZING BETA-CATENIN, FACILITATING ITS ENTRANCE TO THE CELL NUCLEUS, INITIALING PROLIFERATION AND CANCER DEVELOPMENT. DIPLOID CRC CELL LINES TRANSFECTED WITH JCV-CONTAINING PLASMIDS DEVELOPED CIN. THIS RESULT PROVIDES DIRECT EXPERIMENTAL EVIDENCE FOR THE ABILITY OF JCV T-AG TO INDUCE CIN IN THE GENOME OF COLONIC EPITHELIAL CELLS. THE ASSOCIATION OF CRC HMLH1 METHYLATION AND TUMOR POSITIVITY FOR JCV WAS RECENTLY DOCUMENTED. JC VIRUS T-AG DNA SEQUENCES WERE FOUND IN 77% OF CRCS AND ARE ASSOCIATED WITH PROMOTER METHYLATION OF MULTIPLE GENES. HMLH1 WAS METHYLATED IN 25 OUT OF 80 CRC PATIENTS POSITIVE FOR T-AG (31%) IN COMPARISON WITH ONLY ONE OUT OF 11 T-AG NEGATIVE CASES (9%). THUS, JCV CAN MEDIATE BOTH CIN AND ABERRANT METHYLATION IN CRC. LIKE OTHER VIRUSES, CHRONIC INFECTION WITH JCV MAY INDUCE CRC BY DIFFERENT MECHANISMS WHICH SHOULD BE FURTHER INVESTIGATED. THUS, GENE PROMOTER METHYLATION INDUCED BY JCV MAY BE AN IMPORTANT PROCESS IN CRC AND THE POLYP-CARCINOMA SEQUENCE. 2011 17 5349 29 RASSF1A AND DOK1 PROMOTER METHYLATION LEVELS IN HEPATOCELLULAR CARCINOMA, CIRRHOTIC AND NON-CIRRHOTIC LIVER, AND CORRELATION WITH LIVER CANCER IN BRAZILIAN PATIENTS. HEPATOCELLULAR CARCINOMA (HCC) IS THE SECOND MOST COMMON CAUSE OF CANCER MORTALITY WORLDWIDE. MOST CASES OF HCC ARE ASSOCIATED WITH CIRRHOSIS RELATED TO CHRONIC HEPATITIS B VIRUS OR HEPATITIS C VIRUS INFECTIONS. HYPERMETHYLATION OF PROMOTER REGIONS IS THE MAIN EPIGENETIC MECHANISM OF GENE SILENCING AND HAS BEEN INVOLVED IN HCC DEVELOPMENT. THE AIM OF THIS STUDY WAS TO DETERMINE WHETHER ABERRANT METHYLATION OF RASSF1A AND DOK1 GENE PROMOTERS IS ASSOCIATED WITH THE PROGRESSION OF LIVER DISEASE IN BRAZILIAN PATIENTS. METHYLATION LEVELS WERE MEASURED BY PYROSEQUENCING IN 41 (20 HCC, 9 CIRRHOTIC, AND 12 NON-CIRRHOTIC) LIVER TISSUE SAMPLES. MEAN RATES OF METHYLATION IN RASSF1A AND DOK1 WERE 16.2% AND 12.0% IN NON-CIRRHOTIC, 26.1% AND 19.6% IN CIRRHOTIC, AND 59.1% AND 56.0% IN HCC TISSUES, RESPECTIVELY, SHOWING A GRADUAL INCREASE ACCORDING TO THE PROGRESSION OF THE DISEASE, WITH SIGNIFICANTLY HIGHER LEVELS IN TUMOR TISSUES. IN ADDITION, HYPERMETHYLATION OF RASSF1A AND DOK1 WAS FOUND IN THE VAST MAJORITY (88%) OF THE HCC CASES. INTERESTINGLY, DOK1 METHYLATION LEVELS IN HCC SAMPLES WERE SIGNIFICANTLY HIGHER IN THE GROUP OF YOUNGER (<40 YEARS) PATIENTS, AND HIGHER IN MODERATELY DIFFERENTIATED THAN IN POORLY DIFFERENTIATED TUMORS (P < 0.05). OUR RESULTS REINFORCE THE HYPOTHESIS THAT HYPERMETHYLATION OF RASSF1A AND DOK1 CONTRIBUTES TO HEPATOCARCINOGENESIS AND IS ASSOCIATED TO CLINICOPATHOLOGICAL CHARACTERISTICS. RASSF1A AND DOK1 PROMOTER HYPERMETHYLATION MAY BE A VALUABLE BIOMARKER FOR EARLY DIAGNOSIS OF HCC AND A POTENTIAL MOLECULAR TARGET FOR EPIGENETIC-BASED THERAPY. 2016 18 5844 38 STUDY OF PROMOTER HYPOMETHYLATION PROFILES OF RAS ONCOGENES IN HEPATOCELLULAR CARCINOMA DERIVED FROM HEPATITIS C VIRUS GENOTYPE 3A IN PAKISTANI POPULATION. EPIGENETIC MODIFICATIONS SUCH AS DNA METHYLATION CONTRIBUTE TO PROGRESSION OF HEPATITIS C VIRUS (HCV) INFECTION TO LIFE-THREATENING HEPATOCELLULAR CARCINOMA (HCC) BY PROMOTING THE SILENCING OF TUMOR SUPPRESSOR GENES THROUGH DNA HYPERMETHYLATION AND BY CAUSING GENOMIC INSTABILITY THROUGH GLOBAL HYPOMETHYLATION. HOWEVER FEW STUDIES HAVE ADDRESSED THE PROMOTER REGION HYPOMETHYLATION STATUS OF THE ONCOGENES INVOLVED IN HCV DERIVED HCC. IN THIS STUDY, WE ANALYZED THE PROMOTER REGION METHYLATION PATTERN OF RAS ONCOGENES (HRAS, KRAS, AND NRAS) USING METHYLATION-SPECIFIC PCR FOR 50 CHRONIC HCV PATIENTS INFECTED WITH GENOTYPE 3A (27 HCC PATIENTS AND 23 CONTROL NON-HCC PATIENTS). METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION ANALYSIS REVEALED THAT THE NRAS ONCOGENE PROMOTER (P = .0025) WAS SIGNIFICANTLY HYPOMETHYLATED IN HCC PATIENTS COMPARED TO THE NON-HCC PATIENTS SUGGESTING ITS CONTRIBUTION TO THE PROGRESSION OF HCV TOWARDS HCC. TO IDENTIFY THE AGENT FOR ALTERATION IN THE RAS ONCOGENE EXPRESSION, 7 HCV GENES WERE EXPRESSED IN THE HUH-7 CELL LINE FOLLOWED BY MEASUREMENT OF THE NRAS EXPRESSION LEVEL IN HUH-7 BY A QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION. AN INCREASE IN THE MESSENGER RNA LEVEL OF THE NRAS GENE WAS DETECTED WHEN HUH-7 WERE TRANSFECTED WITH CORE, NS5A, AND NS2 GENES. OUR FINDINGS SUGGEST THE INVOLVEMENT OF NRAS ONCOGENE IN THE PATHOGENESIS OF HCV3A DERIVED HCC IN PAKISTANI POPULATION AND ALSO IDENTIFIES THE HCV GENES RESPONSIBLE FOR ITS ENHANCED EXPRESSION. OUR STUDY RAISES THE HYPOTHESIS THAT A SINGLE HCV GENE MAY INCREASE THE CHANCES OF MALIGNANCY. THEREFORE, OUR STUDY MAY HAVE IDENTIFIED A USEFUL EPIGENETIC BIOMARKER OF HCC PROGRESSION IN HCV PATIENTS AND MAY HELP TO DEVELOP NOVEL DIAGNOSTIC TOOLS. 2018 19 2088 32 EPIGENETIC DYSREGULATION OF SECRETED FRIZZLED-RELATED PROTEINS IN MYELOPROLIFERATIVE NEOPLASMS COMPLEMENTS THE JAK2V617F-MUTATION. BACKGROUND: SECRETED FRIZZLED-RELATED PROTEINS (SFRPS) ARE ANTAGONISTS OF THE WNT SIGNALING PATHWAY, WHICH PLAYS A CENTRAL ROLE IN STEM CELL MAINTENANCE AND DIFFERENTIATION OF STEM CELLS AND HEMATOPOIETIC PROGENITORS. EPIGENETIC DOWNREGULATION OF SFRPS BY PROMOTER HYPERMETHYLATION HAS BEEN DESCRIBED TO BE INVOLVED IN THE PATHOGENESIS OF HEMATOPOIETIC MALIGNANCIES. THERE IS AN ASSOCIATION BETWEEN ABERRANT WNT SIGNALING AND THE ESTABLISHED CANCER STEM CELL CONCEPT. IN CONTRAST TO BCR-ABL1-POSITIVE CHRONIC MYELOID LEUKEMIA CML, BCR-ABL1-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS (PH-MPN) ARE CHARACTERIZED BY THE FREQUENT OCCURRENCE OF AN AUTOACTIVATING MUTATION IN THE JAK2 TYROSINE KINASE (JAK2V617F) OR OTHER MUTATIONS IN THE JAK-STAT PATHWAY. HOWEVER, PATHOGENETIC MECHANISMS OF JAK2 MUTATED OR UNMUTATED PH-MPN REMAIN NOT COMPLETELY UNDERSTOOD. WE DETERMINED THE PROMOTER METHYLATION STATUS OF SFRP-1, -2, -4, AND -5 IN 57 MPN PATIENT SAMPLES BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) (MSP). JAK2V617F WAS ASSESSED BY ALLELE-SPECIFIC PCR. RESULTS: ABERRANT METHYLATION AMONG PRIMARY MPN SAMPLES WAS 4% FOR SFRP-1, 25% FOR SFRP-2, 2% FOR SFRP-4, AND 0% FOR SFRP-5. HYPERMETHYLATION OF SFRP-2, WHICH WAS THE MOST FREQUENTLY HYPERMETHYLATED GENE IN OUR STUDY, COULD NOT BE CORRELATED TO ANY SPECIFIC MPN SUBTYPE. HOWEVER, WE DETECTED A SIGNIFICANT CORRELATION BETWEEN SFRP-2 METHYLATION AND PRESENCE OF A JAK2V617F MUTATION (P = 0.008). NONE OF THE 10 CML SAMPLES SHOWED ANY SFRP-METHYLATION. CONCLUSIONS: OUR DATA INDICATE THAT EPIGENETIC DYSREGULATION OF THE WNT SIGNALING PATHWAY IS A COMMON EVENT IN MPN WITH ABERRANT METHYLATION OF AT LEAST ONE SFRP BEING DETECTED IN 25% OF THE PRIMARY PATIENT SAMPLES AND IN 30% IF ONLY ACCOUNTING FOR PH-MPN. A SIGNIFICANT CORRELATION BETWEEN SFRP-2 METHYLATION AND PRESENCE OF JAK2V617F IN OUR DATA SUPPORTS THE HYPOTHESIS THAT EPIGENETIC DYSREGULATION MAY BE A COMPLEMENTARY MECHANISM TO GENETIC ABERRATIONS. ABERRANT METHYLATION OF CRUCIAL STEM CELL MAINTENANCE GENES SEEMS TO CONTRIBUTE TO DISEASE PATHOGENESIS IN PH-MPN. 2012 20 3718 33 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