1 2942 106 GENETIC AND EPIGENETIC ALTERATIONS OF LTF AT 3P21.3 IN NASOPHARYNGEAL CARCINOMA. TO INVESTIGATE THE ROLES OF LACTOTRANSFERRIN GENE (LTF, ALSO REFERRED TO AS THE LACTOFERRIN GENE, LF), LOCATED AT 3P21.3 WITHIN THE COMMON MINIMAL DELETION REGION, IN THE PATHOGENESIS OF NASOPHARYNGEAL CARCINOMA (NPC), WE FIRST DETECTED ITS EXPRESSION LEVEL IN 33 PRIMARY NPC TISSUES AND 15 CHRONIC NASOPHARYNGITIS TISSUES. ABSENT EXPRESSION OR DOWNREGULATION OF LTF WERE OBSERVED IN 76% (25 OF 33) OF PRIMARY NPC TISSUES. WE FURTHER FOUND THAT 25% (5 OF 20) OF NPC SPECIMENS HAD LOSS OF HETEROZYGOSITY (LOH) AT THE LTF LOCUS. LTF MUTATION ASSESSED BY POLYMERASE CHAIN REACTION SINGLE-STRAND CONFORMATION POLYMORPHISM (PCR-SSCP) AND DNA SEQUENCING WAS NOTED IN 30% (6 OF 20) OF PRIMARY NPC TISSUES. IN ADDITION, HYPER-METHYLATION OF LTF PROMOTER REGION WAS FOUND IN 63.6% (21 OF 33) OF PRIMARY NPC SAMPLES BUT NOT IN CHRONIC NASOPHARYNGITIS TISSUES. THE LTF TRANSCRIPTS IN NPC CELL LINES INCREASED UPON TREATMENT WITH THE DEMETHYLATION COMPOUND, 5-AZA-2-DEOXYCYTIDINE. IN CONCLUSION, OUR DATA INDICATE THAT TWO-HIT SILENCING OF LTF THROUGH GENETIC AND EPIGENETIC CHANGES MAY BE A COMMON AND IMPORTANT EVENT IN THE CARCINOGENESIS OF NPC. 2006 2 1996 49 EPIGENETIC AND GENETIC ALTERATIONS OF THE EDNRB GENE IN NASOPHARYNGEAL CARCINOMA. BACKGROUND: LOSS OF HETEROZYGOSITY (LOH) AT 13Q22 IS A COMMON EVENT IN NASOPHARYNGEAL CARCINOMA (NPC). EDNRB GENE LOCATED AT 13Q22 HAS BEEN DEMONSTRATED TO BE HYPERMETHYLATED IN SOME KINDS OF TUMORS. IN THE CURRENT STUDY, WE FOCUSED ON THE EPIGENETIC AND GENETIC ALTERATIONS OF EDNRB IN NPC. METHODS: THE MRNA EXPRESSION OF EDNRB WAS DETECTED BY SEMIQUANTITATIVE RT-PCR AND REAL-TIME QUANTITATIVE PCR IN 49 NPC AND 12 CHRONIC NASOPHARYNGITIS BIOPSIES. THE METHYLATION AND LOH STATUS OF EDNRB WERE EXAMINED BY METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION, MICROSATELLITE PCR AND SEQUENCING. WE ALSO EXAMINED THE MRNA EXPRESSION OF EDNRB IN FOUR NPC CELL LINES AFTER 5-AZA-2'-DEOXYCYTIDINE TREATMENT. RESULTS: EDNRB WAS DOWNREGULATED IN PRIMARY NPC TISSUES AND NPC CELL LINES, AND A RELATIVELY HIGHER METHYLATION LEVEL OF EDNRB WAS FOUND IN NPC BIOPSIES (84%) COMPARED TO THAT IN CHRONIC NASOPHARYNGITIS BIOPSIES (42%). TREATMENT OF NPC CELL LINES WITH 5-AZA-2'-DEOXYCYTIDINE ACTIVATED EDNRB EXPRESSION. LOH OF EDNRB GENE WAS ALSO FOUND AT TWO MICROSATELLITE SITES WITH RATIOS OF 6.25 AND 16.67% IN NPC. CONCLUSION: OUR RESULTS SUGGESTED THAT EDNRB EXPRESSION MAY BE AFFECTED BY ABERRANT PROMOTER METHYLATION AND GENE DELETION AND MAY PLAY A ROLE IN THE DEVELOPMENT OF NPC. 2007 3 3627 60 INACTIVATION OF LARS2, LOCATED AT THE COMMONLY DELETED REGION 3P21.3, BY BOTH EPIGENETIC AND GENETIC MECHANISMS IN NASOPHARYNGEAL CARCINOMA. ALLELIC LOSS OF CHROMOSOME 3P, INCLUDING THE 3P21.3 REGION, IS FOUND IN 95-100% OF PRIMARY NASOPHARYNGEAL CARCINOMA (NPC) BIOPSIES, SUGGESTING THAT THIS REGION SHOULD HARBOR SOME TUMOR SUPPRESSOR GENES (TSGS) CLOSELY RELATED TO NPC DEVELOPMENT. SEVERAL TSGS LOCATED AT 3P21.3, SUCH AS RASSF1A, LTF AND BLU, HAVE BEEN DEMONSTRATED TO BE INVOLVED IN NPC DEVELOPMENT. LARS2 (LEUCYL-TRNA SYNTHETASE 2, MITOCHONDRIAL) IS ANOTHER GENE LOCATED IN THE CHROMOSOME 3 COMMON ELIMINATED REGION-1 (C3CER1) AT 3P21.3. IN THIS STUDY, WE FOCUSSED ON THE EPIGENETIC AND GENETIC ALTERATIONS OF LARS2 IN NPC. THE MRNA EXPRESSION OF LARS2 WAS DETECTED IN 36 NPC AND 8 CHRONIC NASOPHARYNGITIS (NP) TISSUES BY SEMI-QUANTITATIVE REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION (RT-PCR) AND REAL-TIME RT-PCR. SUBSEQUENTLY, THE MUTATION, ALLELIC LOSS, AND METHYLATION STATUS OF LARS2 WERE ANALYSED BY POLYMERASE CHAIN REACTION-SINGLE-STRAND CONFORMATION POLYMORPHISM (PCR-SSCP), HOMOZYGOUS DELETION (HD) ANALYSIS AND METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION IN PRIMARY NPC TISSUES. NO EXPRESSION OR DOWNREGULATION OF LARS2 WAS OBSERVED IN 78% OF PRIMARY NPC TISSUES. NO MUTATIONS, ASSESSED BY PCR-SSCP AND DNA SEQUENCING, WERE FOUND IN THE PROMOTER REGION AND EXON 1 OF LARS2 IN NPC TISSUES, WHEREAS HD WAS DETECTED IN 28% OF NPC SPECIMENS AT THE LARS2 LOCUS. IN ADDITION, HYPERMETHYLATION OF LARS2 WAS FOUND IN 64% OF NPC SAMPLES BUT ONLY IN 12.5% OF NP BIOPSIES. OUR DATA INDICATE THAT INACTIVATION OF LARS2 BY BOTH GENETIC AND EPIGENETIC MECHANISMS MAY BE A COMMON AND IMPORTANT EVENT IN THE CARCINOGENESIS OF NPC. 2009 4 6816 51 [EXPRESSION, GENETIC AND EPIGENETIC ALTERATIONS OF LTF GENE IN NASOPHARYNGEAL CARCINOMA CELL LINES]. OBJECTIVE: TO INVESTIGATE THE EXPRESSION OF LTF MRNA IN SEVERAL NASOPHARYNGEAL CANCER (NPC) CELL LINES, AND ANALYZE THE RELATIONSHIP BETWEEN THE GENETIC AND EPIGENETIC CHANGES AND EXPRESSION OF LTF GENE. METHODS: THE EXPRESSION LEVEL OF LTF WAS DETECTED IN NPC CELL LINES HNE1, HNE2, HNE3, CNE1, CNE2, 5-8F, 6-10B CELLS AND TISSUES OF 15 CASES OF CHRONIC NASOPHARYNGITIS BY RT-PCR. THE LTF PROTEIN LEVEL WAS ANALYZED BY WESTERN BLOTTING IN 6-10B CELLS. THEN LOH, MUTATION AND METHYLATION STATUS OF LTF WAS EXAMINED BY MICROSATELLITES ANALYSIS, PCR-SSCP, MSP AND BISULFITE GENOMIC SEQUENCING, RESPECTIVELY. RESULTS: 15 CHRONIC NASOPHARYNGITIS TISSUES SHOWED STABLE LTF EXPRESSION, WHILE THERE WERE WEAK EXPRESSION IN 6-10B CELLS AND ABSENT EXPRESSION IN REMAINING DETECTED NPC CELL LINES. THERE WAS A SIGNIFICANTLY LOWER LTF EXPRESSION IN CHRONIC NASOPHARYNGITIS TISSUES (Z = -3.738, P = 0.000). NO LTF PROTEIN EXPRESSION WAS OBSERVED IN 6-10B CELLS. LOH ANALYSIS DEMONSTRATED THAT ALLELE LOSS OF LTF WASN'T FOUND IN NPC CELL LINES. LTF MUTATION WAS NOTED IN 14.3% (1/7) OF NPC CELL LINES. DNA SEQUENCING CONFIRMED THE MUTATION POINT IN THE PROMOTER REGION (-305 BP TO -50 BP) WAS AT -218 BP (DEL T) OF LTF GENE IN THE HNE1 CELL LINE. METHYLATION OF LTF GENE WAS NOT FOUND IN CHRONIC NASOPHARYNGITIS. HOWEVER, METHYLATION OF LTF PROMOTER WAS DETECTED IN ALL NPC CELL LINES. LTF MRNA EXPRESSION WAS INCREASED IN 5-8F AND 6-10B CELL LINES AFTER TREATMENT WITH 5-AZA-2-DEOXYCYTIDINE. CONCLUSION: THERE IS AN INACTIVATION OF EXPRESSION OF LTF GENE IN THE NPC CELL LINES. ITS MOLECULAR MECHANISM MAY BE RELATED WITH METHYLATION OF PROMOTER REGION AND DELETION MUTATION. 2010 5 4904 41 P16INK4A GENE ALTERATIONS ARE NOT A PROGNOSTIC INDICATOR FOR SURVIVAL IN PATIENTS WITH HEPATOCELLULAR CARCINOMA UNDERGOING CURATIVE HEPATECTOMY. BACKGROUND AND AIM: HEPATOCELLULAR CARCINOMA (HCC) IS A COMMON MALIGNANCY WORLDWIDE THAT IS HIGHLY ASSOCIATED WITH CHRONIC HEPATITIS B OR C INFECTION AND CIRRHOSIS. THE TUMOR SUPPRESSOR GENE P16INK4A IS AN IMPORTANT COMPONENT OF THE CELL CYCLE AND INACTIVATION OF THE GENE HAS BEEN FOUND IN A VARIETY OF HUMAN CANCERS. THE PRESENT STUDY WAS PERFORMED TO DETERMINE GENETIC AND EPIGENETIC ALTERATIONS IN THE P16INK4A TUMOR SUPPRESSOR GENE AND THE EFFECT OF THESE ON HCC PROGRESSION. METHODS: THE STATUS OF P16INK4A WAS EVALUATED IN 117 HCC TUMORAL NODULES AND 110 CORRESPONDING PERITUMORAL TISSUES BY LOSS OF HETEROZIGOSITY (LOH) AT THE 9P21-22 REGION, HOMOZYGOUS DELETIONS, SINGLE-STRAND CONFORMATION POLYMORPHISM-POLYMERASE CHAIN REACTION (PCR) MUTATIONAL ANALYSIS AND METHYLATION SPECIFIC PCR. RESULTS: THE MOST FREQUENT INACTIVATION MECHANISM WAS HYPERMETHYLATION OF THE PROMOTER REGION, WHICH WAS FOUND IN 63.2% OF THE TUMOR SAMPLES AND IN 28.2% OF THE PERITUMORAL SAMPLES. LOSS OF HETEROZYGOSITY AT THE 9P21 REGION WAS DETECTED IN 27.3% AND 10% OF TUMOR AND PERITUMORAL TISSUES, RESPECTIVELY. HOMOZYGOUS DELETIONS AND MUTATIONS WERE LESS COMMON EVENTS IN HEPATOCARCINOGENESIS. THE AUTHORS FOUND 5.9% OF THE TUMOR CASES WITH EXON 2 HOMOZYGOUS DELETIONS AND 8.6% WITH MUTATIONS. TWO POLYMORPHISMS WERE DETECTED, ONE AT CODON 148 (GCG --> ACG, ALA --> THR) IN THREE CASES AND THE OTHER IN EXON 3 AT 540 BP (34.2% OF THE SAMPLES). NO ASSOCIATION WAS FOUND BETWEEN INACTIVATION OF P16INK4A AND CLINICOPATHOLOGICAL CHARACTERISTICS OR PROGNOSIS. CONCLUSION: P16INK4A IS ALTERED FREQUENTLY AND EARLY IN HCC, BEING THE PREDOMINANT MECHANISM OF INACTIVATION PROMOTER HYPERMETHYLATION. THE PRESENT RESULTS SUGGEST THAT THE P16INK4A GENE PLAYS AN IMPORTANT ROLE IN THE PATHOGENESIS OF HCC. 2004 6 3444 28 HYPERMETHYLATION OF E-CADHERIN IN LEUKEMIA. E-CADHERIN GENE IS OFTEN TERMED A "METASTASIS SUPPRESSOR" GENE BECAUSE THE E-CADHERIN PROTEIN CAN SUPPRESS TUMOR CELL INVASION AND METASTASIS. INACTIVATION OF THE E-CADHERIN GENE OCCURS IN UNDIFFERENTIATED SOLID TUMORS BY BOTH GENETIC AND EPIGENETIC MECHANISMS; HOWEVER, THE ROLE OF E-CADHERIN IN HEMATOLOGIC MALIGNANCIES IS ONLY NOW BEING RECOGNIZED. E-CADHERIN EXPRESSION IS ESSENTIAL FOR ERYTHROBLAST AND NORMOBLAST MATURATION, YET EXPRESSION IS REDUCED OR ABSENT IN LEUKEMIC BLAST CELLS. THIS STUDY EXAMINED THE MESSENGER RNA (MRNA) AND PROTEIN EXPRESSION OF THE E-CADHERIN GENE IN BONE MARROW AND BLOOD SAMPLES FROM NORMAL DONORS AND PATIENTS WITH LEUKEMIA. WE FOUND THAT ALL NORMAL DONOR SAMPLES EXPRESSED E-CADHERIN MRNA, WHEREAS BOTH SAMPLES OF ACUTE MYELOGENOUS LEUKEMIA AND CHRONIC LYMPHOCYTIC LEUKEMIA HAD A SIGNIFICANT REDUCTION OR ABSENCE OF EXPRESSION. HOWEVER, NORMAL BLAST COUNTERPARTS EXPRESSED ONLY A LOW LEVEL OF E-CADHERIN SURFACE PROTEIN. SODIUM BISULPHITE GENOMIC SEQUENCING WAS USED TO FULLY CHARACTERIZE THE METHYLATION PATTERNS OF THE CPG ISLAND ASSOCIATED WITH THE E-CADHERIN GENE PROMOTER IN THOSE SAMPLES WITH MATCHED DNA. ALL OF THE NORMAL CONTROL SAMPLES WERE ESSENTIALLY UNMETHYLATED; HOWEVER, 14 OF 18 (78%) OF THE LEUKEMIA SAMPLES HAD ABNORMAL HYPERMETHYLATION OF THE E-CADHERIN CPG ISLAND. IN FACT BOTH ALLELES OF THE E-CADHERIN GENE WERE OFTEN HYPERMETHYLATED. WE CONCLUDE THE E-CADHERIN GENE IS A COMMON TARGET FOR HYPERMETHYLATION IN HEMATOLOGIC MALIGNANCIES. 2000 7 1968 36 EPIGENETIC ALTERATION OF THE SOCS1 GENE IN CHRONIC MYELOID LEUKAEMIA. THE EXPRESSION OF THE SUPPRESSOR OF CYTOKINE SIGNALLING-1 (SOCS1) PROTEIN IS INDUCED IN RESPONSE TO STIMULATION BY SEVERAL CYTOKINES. THE INDUCED SOCS1 INHIBITS THE SIGNALLING PATHWAY THROUGH THE ASSOCIATION WITH A VARIETY OF TYROSINE KINASE PROTEINS. IN THIS STUDY, THE MUTATION ANALYSES, CPG ISLAND METHYLATION STATUS, AND THE EXPRESSION OF THE SOCS1 GENE IN 112 CHRONIC MYELOID LEUKAEMIA (CML) SAMPLES, FIVE LEUKAEMIA CELL LINES, AND 30 NORMAL CONTROLS WERE ANALYSED. NO GENETIC MUTATIONS OF SOCS1 GENE WERE NOTED IN THE CML SAMPLES. THE SOCS1 GENE WAS HYPERMETHYLATED IN 67% AND 46% OF THE BLASTIC AND CHRONIC PHASE CML SAMPLES RESPECTIVELY (P < 0.0001). HOWEVER, THERE WAS NO METHYLATION OF THE SOCS1 GENE IN NORMAL CONTROLS OR CML IN MOLECULAR REMISSION. THE METHYLATION STATUS OF THE SOCS1 GENE IS CONSISTENT WITH THE RESULTS OF THE REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION AND IMMUNOCYTOCHEMISTRY STAINING. OUR RESULTS DEMONSTRATE THAT THE SOCS1 GENE SILENCING IS CAUSED BY THE METHYLATION OF CPG ISLANDS IN CML AND IS REVERSED TO AN UNMETHYLATED STATUS IN MOLECULAR REMISSION. AS SOCS1 HAS UNIVERSAL ACTIVITY TO NEGATIVELY REGULATE SEVERAL CYTOKINE SIGNALLING PATHWAYS, THE LOSS OF THE NEGATIVE REGULATION OF CYTOKINE SIGNALLING BY THE SOCS1 MAY PLAY A ROLE IN THE PATHOGENESIS OF CML PROGRESSION. 2003 8 4905 33 P16INK4A HYPERMETHYLATION IS ASSOCIATED WITH HEPATITIS VIRUS INFECTION, AGE, AND GENDER IN HEPATOCELLULAR CARCINOMA. PURPOSE: THE TUMOR SUPPRESSOR GENE P16INK4A IS MAINLY INACTIVATED BY AN EPIGENETIC CHANGE INVOLVING PROMOTER HYPERMETHYLATION IN HEPATOCARCINOGENESIS. THE POSSIBLE CLINICAL IMPACT OF P16INK4A METHYLATION AND THE POTENTIAL RISK FACTORS FOR THIS EPIGENETIC ALTERATION HAVE NOT BEEN THOROUGHLY INVESTIGATED. EXPERIMENTAL DESIGN: WE STUDIED THE METHYLATION STATUS AND MRNA AND PROTEIN EXPRESSION OF P16INK4A IN 50 HEPATOCELLULAR CARCINOMAS AND CORRESPONDING NONNEOPLASTIC LIVER LESIONS USING METHYLATION-SPECIFIC PCR, REVERSE TRANSCRIPTION-PCR, AND IMMUNOHISTOCHEMICAL TECHNIQUES. RESULTS: P16INK4A HYPERMETHYLATION WAS OBSERVED IN 58% (29 OF 50) OF THE HEPATOCELLULAR CARCINOMAS AND 16% (6 OF 38) OF THE CORRESPONDING CHRONIC HEPATITIS AND CIRRHOSIS TISSUE SAMPLES. P16INK4A METHYLATION WAS SIGNIFICANTLY ASSOCIATED WITH MRNA AND PROTEIN EXPRESSION (P <0.001 AND P=0.003, RESPECTIVELY). ALL OF THE P16INK4A-METHYLATED TUMORS WERE POSITIVE FOR HEPATITIS B VIRUS OR HEPATITIS C VIRUS MARKERS, BUT NONE OF THE VIRUS-NEGATIVE TUMORS EXHIBITED P16INK4A METHYLATION (P=0.006). THE FREQUENCY OF P16INK4A HYPERMETHYLATION TENDED TO BE HIGHER IN HEPATITIS C VIRUS-RELATED TUMORS (23 OF 32, 72%) THAN IN HEPATITIS B VIRUS-RELATED TUMORS (6 OF 13, 46%; P=0.1). ABERRANT METHYLATION OF P16INK4A WAS ALSO RELATED SIGNIFICANTLY TO INCREASING AGE, FEMALE GENDER, AND NORMAL LEVELS OF SERUM PIVKA-II (P=0.02, 0.04, AND 0.04, RESPECTIVELY). NO STATISTICALLY SIGNIFICANT DIFFERENCE IN SURVIVAL WAS OBSERVED BETWEEN PATIENTS WITH P16INK4A HYPERMETHYLATION AND THOSE WITHOUT. CONCLUSIONS: OUR OBSERVATIONS SUGGEST THAT P16INK4A HYPERMETHYLATION MAY CONTRIBUTE TO HEPATOCARCINOGENESIS FROM AN EARLY STAGE AND THAT MULTIPLE RISK FACTORS, SUCH AS VIRAL INFECTIONS, AGE, AND GENDER, MAY BE ASSOCIATED WITH P16INK4A HYPERMETHYLATION IN HEPATOCARCINOGENESIS. 2004 9 1620 33 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 10 3646 28 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 11 878 33 CHRONIC CADMIUM EXPOSURE AGGRAVATES MALIGNANT PHENOTYPES OF NASOPHARYNGEAL CARCINOMA BY ACTIVATING THE WNT/BETA-CATENIN SIGNALING PATHWAY VIA HYPERMETHYLATION OF THE CASEIN KINASE 1ALPHA PROMOTER. BACKGROUND: OUR PREVIOUS STUDY HAS SHOWN THAT CADMIUM (CD) EXPOSURE IS NOT ONLY A RISK FACTOR FOR NASOPHARYNGEAL CARCINOMA (NPC), BUT ALSO CORRELATED WITH THE CLINICAL STAGE AND LYMPH NODE METASTASIS. HOWEVER, THE UNDERLYING MOLECULAR EVENTS OF CD INVOLVED IN NPC PROGRESSION REMAIN TO BE ELUCIDATED. PURPOSE: THE OBJECTIVE OF THIS STUDY WAS TO DECIPHER HOW CD IMPACTS THE MALIGNANT PHENOTYPES OF NPC CELLS. METHODS: NPC CELL LINES CNE-1 AND CNE-2 WERE CONTINUOUSLY EXPOSED WITH 1 MUM CD CHLORIDE FOR 10 WEEKS, DESIGNATING AS CHRONIC CD TREATED NPC CELLS (CCT-NPC). MTT ASSAY, COLONY FORMATION ASSAY AND XENOGRAFT TUMOR GROWTH WERE USED TO ASSESS CELL VIABILITY IN VITRO AND IN VIVO. TRANSWELL ASSAYS WERE PERFORMED TO DETECT CELL INVASION AND MIGRATION. THE PROTEIN LEVELS OF E-CADHERIN, N-CADHERIN, VIMENTIN AS WELL AS BETA-CATENIN AND CASEIN KINASE 1ALPHA(CK1ALPHA) WERE MEASURED BY WESTERN BLOT. IMMUNOFLUORESCENCE STAINING WAS USED TO OBSERVE THE DISTRIBUTION OF FILAMENT ACTIN (F-ACTIN), BETA-CATENIN AND CK1ALPHA. THE MRNA LEVELS OF DOWNSTREAM TARGET GENES OF BETA-CATENIN WERE DETECTED BY RT-PCR. WNT/BETA-CATENIN SIGNALING ACTIVITY WAS ASSESSED BY TOPFLASH/FOPFLASH DUAL LUCIFERASE REPORT SYSTEM. MS-PCR WAS USED TO DETECT THE METHYLATION STATUS OF CK1ALPHA. FINALLY, THE ACTIVATION OF WNT/BETA-CATENIN PATHWAY AND CELL BIOLOGICAL PROPERTIES WERE EXAMINED FOLLOWING TREATMENT OF CCT-NPC CELLS WITH 5-AZA-2-DEOXY-CYTIDINE(5-AZA-CDR). RESULTS: CCT-NPC CELLS SHOWED AN INCREASE IN CELL PROLIFERATION, COLONY FORMATION, INVASION AND MIGRATION COMPARED TO THE PARENTAL CELLS. CD ALSO INDUCED CYTOSKELETON REORGANIZATION AND EPITHELIAL-TO-MESENCHYMAL TRANSITION. UPREGULATION AND NUCLEAR TRANSLOCATION OF BETA-CATENIN AND INCREASED LUCIFERASE ACTIVITY ACCOMPANIED WITH TRANSCRIPTION OF DOWNSTREAM TARGET GENES WERE FOUND IN CCT-NPC CELLS. TREATMENT OF CCT-CNE1 CELLS WITH 5-AZA-CDR COULD REVERSE THE HYPERMETHYLATION OF CK1ALPHA AND ATTENUATE THE CELL MALIGNANCY. CONCLUSION: THESE RESULTS SUPPORT A ROLE FOR CHRONIC CD EXPOSURE AS A DRIVING FORCE FOR THE MALIGNANT PROGRESSION OF NPC VIA EPIGENETIC ACTIVATION OF THE WNT/BETA-CATENIN PATHWAY. 2019 12 6820 34 [GASTRIC CARCINOMA AND CHRONIC GASTRITIS: EPIGENETIC REGULATION OF CDH1 (E-CADHERIN), CDKN2A (P16INK4A), PTGS2 (COX-2) AND EGFR GENES THROUGH METHYLATION]. THE GENETIC AND EPIGENETIC ALTERATIONS ARE BEING STUDIED AS ONE OF THE CAUSES OF GASTRIC CANCER (GC) PROGRESSION AND DEVELOPMENT. DNA METHYLATION IS AN EPIGENETIC ALTERATION WHICH LEADS TO SUPPRESSOR GENE SILENCING AND PROTO-ONCOGENE ACTIVATION, PLAYING AN IMPORTANT ROLE IN CARCINOGENESIS. THE HISTOLOGICAL TYPES OF GASTRIC CARCINOMA HAVE DIFFERENT GENETIC PATHS AND THE KNOWLEDGE OF THE MOLECULAR BASES OF TUMORAL PROGRESSION LEADS TO DIAGNOSTIC ACCURACY AND ATTEMPTED THERAPY. CDH1 (E-CADHERIN) AND CDKN2A (P16(INK4A)) GENES ARE THOUGHT TO BE TUMORAL SUPPRESSOR GENES AND PTGS2 (COX-2) AND GENES ARE INVOLVED IN TUMOUR REGULATION AND GROWTH. IN ONE HAND, GENE SILENCING AS AN EPIGENETIC PHENOMENON, AND IN THE OTHER HAND, GENE EXPRESSION ENHANCEMENT DUE TO POSSIBLE DEMETHYLATION, SIMULTANEOUSLY, CAN FACILITATE CARCINOGENESIS AND TUMORAL PROGRESSION. OUR AIM WAS TO RELATE CDH1, P16(INK4A), COX-2 AND EGFR GENES DNA METHYLATION WITH THE SEVERAL HISTOLOGICAL TYPES OF GASTRIC CARCINOMA AND CHRONIC GASTRITIS. WE STUDIED 55 FORMALIN FIXED PARAFFIN EMBEDDED GASTRIC BIOPSIES: 35 WERE GC SPECIMENS (12 DIFFUSE TYPE, 15 INTESTINAL TYPE AND 8 INDETERMINATE TYPE, ACCORDING TO LAUREN'S CLASSIFICATION) AND 20 SAMPLES HAD CHRONIC GASTRITIS (CG). THE DNA WAS TREATED WITH SODIUM BISULFITE AFTER EXTRACTION AND THEN PERFORMED METHYLATION SPECIFIC PCR (MSP). STATISTICAL ANALYSIS WAS BASED ON CHI-SQUARE TEST AND EXACT FISHER'S TEST. CPG ISLAND METHYLATION WAS DETECTED IN 94% OF THE GC SAMPLES FOR CDH1, 91% FOR COX-2, 80% FOR P16(INK4A) AND NO METHYLATION WAS DETECTED IN EGFR GENE (0%). IN CG, CPG ISLAND METHYLATION WAS FOUND IN 100% FOR CDH1 AND COX-2 GENES, 90% FOR P16(INK4A) AND 20% FOR EGFR. THESE RESULTS REVEAL SIGNIFICANT DIFFERENCES IN EGFR GENE METHYLATION DISTINGUISHING GC FROM CG (P < 0, 01), SUGGESTING THAT GENE DEMETHYLATION LEADS TO MALIGNANT TRANSFORMATION AND FAVOURS THE USE OF TYROSINE-KINASE INHIBITORS IN ITS TREATMENT. GENES COX2 E P16INK4A LOWER METHYLATION IN INTESTINAL AND DIFFUSE TYPES OF GC, FAVOURS THEIR DIFFERENT ROLE IN RESPECTIVE HISTOGENESIS. 2010 13 1342 37 DETECTING ABNORMAL METHYLATION OF TUMOR SUPPRESSOR GENES GSTP1, P16, RIZ1, AND RASSF1A IN HEPATOCELLULAR CARCINOMA AND ITS CLINICAL SIGNIFICANCE. HEPATOCELLULAR CARCINOMA (HCC) HAS A HIGH RATE OF MORTALITY. FURTHER STUDIES INTO EPIGENETIC CHANGES IN HCC, PARTICULARLY THE ABNORMAL METHYLATION OF TUMOR SUPPRESSOR GENES (TSGS), ARE REQUIRED, SINCE THESE CHANGES MAY PROVIDE NOVEL BIOMARKERS FOR EARLY SCREENING AND DIAGNOSIS OF HCC. BY USING METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), THE PRESENT STUDY DETECTED THE METHYLATION STATUS IN THE PROMOTER REGION OF 4 CANDIDATE TSGS, GSTP1, P16, RIZ1, AND RASSF1A, RESPECTIVELY, IN 35 PAIRED HCC AND TUMOR-ADJACENT LIVER TISSUES IN ADDITION TO 20 NORMAL LIVER TISSUES. THEIR EFFECT ON THE INITIATION AND PROGRESSION OF HCC WAS ALSO INVESTIGATED BY ANALYZING THE CLINICOPATHOLOGICAL DATA. THE RESULTS OF THE PRESENT STUDY REVEALED THAT THE METHYLATION LEVEL OF RIZ1 AND GSTP1 GENES IN HCC WAS SIGNIFICANTLY INCREASED COMPARED WITH THAT IN THE ADJACENT TISSUES (P<0.01) AND THE NORMAL LIVER TISSUES (P<0.01). THE METHYLATION FREQUENCY OF P16 AND RASSF1A GENES WAS NOT SIGNIFICANTLY INCREASED COMPARED WITH THAT OBSERVED IN THE ADJACENT TISSUES (P>0.05) BUT WAS SIGNIFICANTLY INCREASED COMPARED WITH THE NORMAL TISSUES (P<0.01). IN HCC TISSUES, THE METHYLATION FREQUENCY OF THE GSTP1 GENE IN TUMORS WITH CAPSULAR INVASION WAS SIGNIFICANTLY INCREASED COMPARED WITH THAT IN TUMORS WITHOUT CAPSULAR INVASION (P<0.05). THE METHYLATION FREQUENCY OF P16 GENE IN HEPATITIS B SURFACE ANTIGEN (HBSAG)-POSITIVE HCC PATIENTS WAS SIGNIFICANTLY INCREASED COMPARED WITH THAT IN HBSAG-NEGATIVE PATIENTS (P<0.05). THE METHYLATION STATUS OF RIZ1 AND RASSF1A GENES WAS NOT SIGNIFICANTLY CORRELATED WITH THE CLINICOPATHOLOGICAL DATA (P>0.05). PREVIOUS STUDIES HAVE DEMONSTRATED THAT THE METHYLATION STATUS OF RIZ1 AND GSTP1 GENES IS HCC-SPECIFIC, AND THUS MAY BE USED AS A BIOMARKER TO ASSIST THE CLINICAL DIAGNOSIS OF HCC. WHILE THE METHYLATION OF GSTP1 GENE PROMOTER MAY ASSOCIATE WITH THE INVASIVENESS OF HCC, CHRONIC HEPATITIS B VIRUS INFECTION MAY BE THE CAUSE OF METHYLATION-INDUCED P16 INACTIVATION. 2015 14 2847 22 FREQUENT P15 PROMOTER METHYLATION IN TUMOR AND PERIPHERAL BLOOD FROM HEPATOCELLULAR CARCINOMA PATIENTS. WE PROSPECTIVELY ANALYZED P15 METHYLATION PATTERNS IN 25 SURGICALLY RESECTED TUMORS AND 130 PLASMA, SERUM, AND BUFFY COAT SAMPLES FROM HEPATOCELLULAR CARCINOMA (HCC) PATIENTS, CONTROLS WITH CHRONIC HEPATITIS/CIRRHOSIS, AND HEALTHY SUBJECTS. USING METHYLATION-SPECIFIC PCR, WE DEMONSTRATED FOR THE FIRST TIME P15 PROMOTER METHYLATION IN 64% OF TUMORS AND 25% (4 OF 16) OF PATIENTS' PLASMA AND SERUM SAMPLES. CONCURRENT P15 AND P16 METHYLATION WAS SHOWN IN 48% OF TUMORS, AND P15/P16 METHYLATION WAS DETECTED IN THE PLASMA/SERUM OF 92% (11 OF 12) OF PATIENTS. OF NOTE, 75% OF 12 PATIENTS WITH CONCURRENT TUMOR METHYLATION DEVELOPED CLINICAL METASTASIS/RECURRENCE (P = 0.027). IN BUFFY COAT SAMPLES, P15 METHYLATION WAS DETECTED IN ALL EIGHT PATIENTS WITH TUMOR P15 METHYLATION, SUGGESTING THE PRESENCE OF CIRCULATING TUMOR CELLS. NONE OF THE CONTROL SAMPLES WERE METHYLATION POSITIVE. OUR DATA UNDERSCORE THE IMPORTANT ROLE(S) OF P15 AND P16 METHYLATION IN HEPATOCARCINOGENESIS AND TUMOR PROGRESSION. AMONG 92% (23 OF 25) OF PATIENTS WITH TUMOR P15/P16 METHYLATION, CIRCULATING TUMOR DNA AND HCC CELLS WERE DETECTED IN THE PERIPHERAL BLOOD OF 87% (20 OF 23) OF PATIENTS. THE COMBINATION OF THESE EPIGENETIC MARKERS MAY PROVE VALUABLE FOR NONINVASIVE HCC DIAGNOSIS AND DISEASE MONITORING. 2000 15 2135 37 EPIGENETIC INACTIVATION OF TUMOR SUPPRESSOR GENES IN SERUM OF PATIENTS WITH CUTANEOUS MELANOMA. SMALL AMOUNTS OF CELL-FREE DNA CIRCULATE IN BOTH HEALTHY AND DISEASED HUMAN BLOOD, WHILE INCREASED CONCENTRATIONS OF DNA ARE PRESENT IN THE SERUM OF CANCER PATIENTS. TUMOR-SPECIFIC MUTATIONS OR EPIGENETIC MODIFICATIONS HAVE PREDOMINANTLY BEEN DETECTED IN TISSUE SPECIMENS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE METHYLATION OF FIVE DIFFERENT GENES INVOLVED IN TUMOR SUPPRESSION AND DNA REPAIR (SUPPRESSORS OF CYTOKINE SIGNALING 1 AND 2 (SOCS1, SOCS2)), RAS-ASSOCIATION DOMAIN FAMILY PROTEIN 1A (RASSF1A), D-TYPE P16(INK4A) CYCLIN-DEPENDENT KINASE INHIBITOR (CDKN), AND O6-METHYLGUANINE DNA-METHYLTRANSFERASE (MGMT)) IN THE SERUM OF 100 PATIENTS USING METHYLATION-SPECIFIC PCR. IN ALL, 41 MELANOMA PATIENTS (STAGE I = 18; STAGE II = 10; STAGE III/IV = 13), 13 HEALTHY CONTROLS WITHOUT NEVI, AND 10 INDIVIDUALS WITH MORE THAN 15 NEVI OF >5 MM IN SIZE WERE INVESTIGATED. FOR COMPARISON, SERA FROM PATIENTS WITH OTHER SKIN TUMORS (NINE BASAL CELL CANCERS, FIVE KAPOSI'S SARCOMA), DIFFERENT METASTASIZED CANCERS (FIVE BREAST CANCERS, FIVE COLON CANCERS), AND SEVERAL CHRONIC INFLAMMATORY DISEASES (N = 12) WERE ALSO ANALYZED. IN ADDITION, WE EXAMINED IF METHYLATION WAS INVOLVED IN SILENCING TRANSCRIPTION OF THESE GENES IN 12 MELANOMA SPECIMENS. SOCS1, SOCS2, RASSF1A, CDKN2A, AND MGMT WERE METHYLATED IN 75, 43, 64, 75, AND 64% OF MELANOMA SAMPLES, RESPECTIVELY. OF THE 41 MELANOMA PATIENTS, 83% HAD ONE HYPERMETHYLATED GENE, WHILE 66, 51, AND 41% HAD TWO, THREE, OR FOUR HYPERMETHYLATED GENES, RESPECTIVELY. ALSO, 20% OF THESE PATIENTS SHOWED HYPERMETHYLATION FOR ALL GENES, WHILE ONLY 17% SHOWED NO METHYLATION. IMPORTANTLY, THE METHYLATION PROFILE OF THE SELECTED GENES FROM MELANOMA PATIENTS WAS DISTINCT FROM THE OTHER ANALYZED TUMORS. TRANSCRIPTION OF SOCS1, SOCS2, CDKN2A, AND RASSF1A GENES WAS SIGNIFICANTLY REDUCED IN FRESH MELANOMA SAMPLES, WHILE MGMT SHOWED A 12-FOLD UPREGULATION AT THE MESSENGER RIBONUCLEIC ACID LEVEL (P < 0.001). OUR FINDINGS SUGGEST THAT EPIGENETIC SILENCING OF THE STUDIED TUMOR SUPPRESSOR GENES IS A COMMON AND PROBABLY IMPORTANT MECHANISM FOR MELANOMA FORMATION. THIS CONVENIENT METHOD USING A SIMPLE BLOOD SAMPLE MAY CONTRIBUTE TO CLASSIFICATION OF MELANOMA AND AWAITS CLINICAL VALIDATION. 2006 16 1805 25 EFFECT OF SMOKING ON THE DNA METHYLATION PATTERN OF THE SOCS1 PROMOTER IN EPITHELIAL CELLS FROM THE SALIVA OF PATIENTS WITH CHRONIC PERIODONTITIS. BACKGROUND: THE AIM OF THE PRESENT STUDY WAS TO EVALUATE THE METHYLATION PATTERN IN THE SUPPRESSOR OF CYTOKINE SIGNALING 1 (SOCS1) GENE IN SMOKERS AND NON-SMOKERS WITH CHRONIC PERIODONTITIS (CP). METHODS: METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) WAS PERFORMED TO DETERMINE THE METHYLATION STATUS OF THE SOCS1 PROMOTER IN 45 SALIVA SAMPLES FROM SMOKERS AND NON-SMOKERS WITH CP. RESULTS: CELLS FROM THE SALIVA OF CP PATIENTS WHO SMOKED WERE 7.08 TIMES MORE LIKELY TO HAVE A METHYLATED SOCS1 PROMOTER THAN CELLS FROM THE SALIVA OF NON-SMOKING PATIENTS. CONCLUSIONS: SOCS1 GENE PROMOTER METHYLATION, WITH ITS POTENTIAL EFFECTS ON THE EXPRESSION OF THIS GENE, SEEMS TO BE A CONSEQUENCE OF EXPOSURE TO TOBACCO AND NOT TO PERIODONTAL DISEASE. FURTHER STUDIES ARE NEEDED TO ELUCIDATE THE RELATIONSHIP BETWEEN THE EPIGENETIC CONTROL OF IMMUNE RESPONSE GENE EXPRESSION, EXPOSURE TO ENVIRONMENTAL FACTORS, AND THE DEVELOPMENT, PROGRESSION, AND PROGNOSIS OF CP. 2019 17 2436 35 EPIGENETIC SILENCING OF SOCS3 IDENTIFIES A SUBSET OF PROSTATE CANCER WITH AN AGGRESSIVE BEHAVIOR. BACKGROUND: CHRONIC INFLAMMATION AND SUBSEQUENT TISSUTAL ALTERATIONS MAY PLAY A KEY ROLE IN PROSTATE CARCINOGENESIS. IN THIS WAY, MOLECULAR ALTERATIONS OF THE SUPPRESSOR OF CYTOKINE SIGNALING 3 (SOCS3), ONE OF THE MOST IMPORTANT INHIBITORY MOLECULE OF INFLAMMATORY SIGNAL TRANSDUCTION CIRCUITRIES, COULD CONTRIBUTE TO EXPLAIN THE PLEIOTROPIC ROLE OF INTERLEUKIN-6 (IL-6) IN THIS TYPE OF CANCER. METHODS: WE ANALYZED THE METHYLATION STATUS AND MRNA EXPRESSION OF SOCS3 IN 20 BENIGN PROSTATE HYPERPLASIAS (BPH) AND IN 51 PROSTATE CANCER SPECIMENS. WE ANALYZED THE SOCS3 METHYLATION STATUS USING METHYLATION-SPECIFIC PCR. HYPERMETHYLATION WAS CONFIRMED BY SEQUENCING AFTER SUBCLONING. EPIGENETIC SILENCING OF THIS GENE WAS ALSO DEMONSTRATED BY REAL-TIME PCR AND BY IMMUNOHISTOCHEMISTRY. RESULTS AND CORRELATION WITH CLINICAL DATA WERE STATISTICALLY ANALYZED. RESULTS: WE FOUND THAT THE PROMOTER OF SOCS3 WAS METHYLATED IN 39.2% OF PROSTATE CANCER. ON THE CONTRARY, ALL BPH AND NORMAL CONTROLS HAD AN UNMETHYLATED PATTERN. REAL-TIME ANALYSIS SHOWED THAT IN METHYLATED CASES SOCS3 MRNA EXPRESSION WAS REDUCED BY THREE AND FOUR FOLDS AS COMPARED TO BPH AND UNMETHYLATED CASES, RESPECTIVELY. INTERESTINGLY, SOCS3 MRNA LEVEL WAS HIGHER IN UNMETHYLATED PROSTATE CANCER THAN IN BPH. THE IMMUNOHISTOCHEMICAL STAINING ANALYSIS FOR SOCS 3 CONFIRMED MRNA RESULTS. MOREOVER, METHYLATION OF SOCS3 PROMOTER SIGNIFICANTLY ASSOCIATED WITH INTERMEDIATE-HIGH GRADE GLEASON SCORE (P = 0.0007) AND WITH AN UNFAVORABLE CLINICAL OUTCOME (P = 0.0019). CONCLUSIONS: OUR DATA SUGGEST THAT SOCS3 HYPERMETHYLATION MAY BE INVOLVED IN THE PATHOGENESIS OF PROSTATE CANCER AND COULD IDENTIFY A TUMOR SUBSET WITH AN AGGRESSIVE BEHAVIOR. 2011 18 1617 32 DNA METHYLTRANSFERASE EXPRESSION AND DNA METHYLATION IN HUMAN HEPATOCELLULAR CARCINOMA AND THEIR CLINICOPATHOLOGICAL CORRELATION. ABERRANT DNA METHYLATION ON CPG ISLANDS IS ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS, AND THE METHYLATION PROCESS IS CATALYZED BY DNA METHYLTRANSFERASE (DNMT). WE EVALUATED I) THE MRNA LEVELS OF THREE DNMTS; DNMT1, DNMT3A AND DNMT3B, IN 25 HEPATOCELLULAR CARCINOMAS (HCCS), IN THEIR CORRESPONDING NON-CANCEROUS LIVER TISSUES AND IN 7 NORMAL LIVERS BY USING REAL-TIME REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION; II) NUCLEAR EXPRESSION OF DNMT1 AND DNMT3A PROTEINS IN THE HCCS BY IMMUNOHISTOCHEMISTRY, III) THE METHYLATION STATUS OF 5 GENES; P16, P15, E-CADHERIN, HIC-1 AND RASSF1A IN THE SAME TISSUES, AND IV) THE RELATIONSHIPS BETWEEN THE ABOVE RESULTS AND THE CLINICOPATHOLOGICAL CHARACTERISTICS, INCLUDING PROGNOSIS. THE DIFFERENCES IN MRNA EXPRESSION LEVELS FOR DNMT1, DNMT3A AND DNMT3B WERE STATISTICALLY SIGNIFICANT BETWEEN HCC AND NORMAL LIVERS (P<0.001), HCC AND CHRONIC HEPATITIS (P<0.001) AND HCC AND CIRRHOSIS (P<0.001). AN INCREASE IN MRNA EXPRESSION LEVELS OF >4-FOLD FOR DNMT3B IN HCCS WAS SIGNIFICANTLY ASSOCIATED WITH A POORER OVERALL SURVIVAL (P=0.027) AND SHORTER METASTASIS-FREE SURVIVAL (P=0.0299). A POORER RECURRENCE-FREE SURVIVAL WAS NOTED IN HCCS WITH A >4-FOLD INCREASE IN DNMT3A MRNA (P=0.0120). THE AVERAGE NUMBERS OF METHYLATED GENES WERE 0, 1.27, 1.38 AND 2.72 FOR NORMAL LIVERS, CHRONIC HEPATITIS, CIRRHOSIS AND HCCS, RESPECTIVELY, AND THIS PROGRESSIVE INCREASE FROM NORMAL LIVERS TO CHRONIC HEPATITIS/CIRRHOSIS THROUGH HCC MAY SUGGEST THAT TUMOR SUPPRESSOR GENE METHYLATION IS AN EARLY EVENT IN HEPATOCARCINOGENESIS. THESE RESULTS FIRST SUGGEST THAT HEPATOCARCINOGENESIS INVOLVES AN INCREASED EXPRESSION OF DNMT1, DNMT3A AND DNMT3B MRNA AND A PROGRESSIVE INCREASE IN THE NUMBER OF METHYLATED GENES FROM NORMAL LIVER, CHRONIC HEPATITIS/CIRRHOSIS TO HCC AND SECONDLY THAT AN INCREASE IN THE DNMT3A AND DNMT3B MRNA LEVELS IN HCCS RELATIVE TO THEIR NON-CANCEROUS TISSUES MAY BE A PREDICTOR OF POOR SURVIVAL. 2007 19 6415 36 THE STUDY OF P16 AND P15 GENE METHYLATION IN HEAD AND NECK SQUAMOUS CELL CARCINOMA AND THEIR QUANTITATIVE EVALUATION IN PLASMA BY REAL-TIME PCR. EPIGENETIC SILENCING OF THE P16 AND P15 GENES BY PROMOTER METHYLATION ARE COMMONLY OBSERVED IN HUMAN EPITHELIAL MALIGNANCIES, INCLUDING HEAD AND NECK SQUAMOUS CELL CARCINOMAS (HNSCC). IN THIS STUDY, A METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP) WAS USED TO EVALUATE THE METHYLATION STATUS OF THE P16 AND P15 GENES IN 73 HNSCC SURGICAL SPECIMENS. P16 AND P15 GENE METHYLATION WAS ALSO EXAMINED IN 29 PAIRED METASTATIC LYMPH NODES AND 29 PAIRED HISTOLOGICALLY, NORMAL RESECTION MARGIN MUCOSAE. THE QUANTITY OF CELL-FREE METHYLATED P16 AND P15 DNA IN THE PLASMA SAMPLES OF 20 HNSCC PATIENTS AND 24 HEALTHY CONTROLS WAS ALSO EXAMINED USING A FLUORESCENCE-BASED REAL-TIME PCR ASSAY. THE FREQUENCIES OF P16 AND P15 METHYLATION IN THE PRIMARY TUMOUR WERE 49% AND 60%, RESPECTIVELY. CONCORDANT METHYLATION OF P16 AND P15 IN TUMOUR SAMPLES AND METASTATIC LYMPH NODES WAS FOUND IN 59 AND 38% OF CASES, RESPECTIVELY. A SIGNIFICANTLY HIGHER PREVALENCE OF P15 METHYLATION WAS FOUND IN HISTOLOGICALLY-NORMAL SURGICAL MARGIN EPITHELIA OF HNSCC PATIENTS WITH CHRONIC SMOKING AND DRINKING HABITS COMPARED WITH NON-SMOKERS AND NON-DRINKERS. IN ADDITION, METHYLATED P16 AND P15 DNA LEVELS WERE SIGNIFICANTLY HIGHER IN THE PLASMA OF HNSCC PATIENTS (MEAN 56 COPIES/ML PLASMA AND 65 COPIES/ML PLASMA, RESPECTIVELY) COMPARED WITH NORMAL CONTROLS (MEAN 6 COPIES/ML PLASMA AND 16 COPIES/ML PLASMA, RESPECTIVELY). IN CONCLUSION, PROMOTER METHYLATION OF THE P16 AND P15 GENES IS INVOLVED IN THE PATHOGENESIS OF HNSCC AND MAY BE RELATED TO CHRONIC SMOKING AND DRINKING. THE DIFFERENTIAL LEVELS OF METHYLATED P16 AND P15 DNA IN PLASMA MIGHT BE POTENTIAL USEFUL MARKERS IN SCREENING HIGH-RISK POPULATIONS FOR EARLY HNSCC AND MONITORING THEIR TREATMENT RESPONSE. 2003 20 1146 40 CONCURRENT EPIGENETIC SILENCING OF WNT/BETA-CATENIN PATHWAY INHIBITOR GENES IN B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA. BACKGROUND: THE WNT/BETA-CATENIN SIGNALLING IS ABERRANTLY ACTIVATED IN PRIMARY B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL). EPIGENETIC SILENCING OF PATHWAY INHIBITOR GENES MAY BE A MECHANISM FOR ITS ACTIVATION. IN THIS STUDY, WE INVESTIGATED SYSTEMATICALLY AND QUANTITATIVELY THE METHYLATION STATUS OF 12 WNT/BETA-CATENIN PATHWAY INHIBITOR GENES - CDH1, DACT1, DKK1, DKK2, DKK3, DKK4, SFRP1, SFRP2, SFRP3, SFRP4, SFRP5 AND WIF1 - IN THE CELL LINES EHEB AND MEC-1 AS WELL AS PATIENT SAMPLES. METHODS: QUANTIFICATION OF DNA METHYLATION WAS PERFORMED BY MEANS OF BISULPHITE PYROSEQUENCING AND CONFIRMED BY BISULPHITE SANGER SEQUENCING. GENE EXPRESSION WAS ANALYSED BY QPCR USING GAPDH AS INTERNAL CONTROL. E-CADHERIN AND BETA-CATENIN PROTEIN QUANTIFICATION WAS CARRIED OUT BY MICROSPHERE-BASED IMMUNOASSAYS. METHYLATION DIFFERENCES OBSERVED BETWEEN THE PATIENT AND CONTROL GROUPS WERE TESTED USING GENERALISED LEAST SQUARES MODELS. RESULTS: FOR 10 GENES, A HIGHER METHYLATION LEVEL WAS OBSERVED IN TUMOUR MATERIAL. ONLY DKK4 EXHIBITED SIMILARLY HIGH METHYLATION LEVELS IN BOTH TUMOUR AND NORMAL SPECIMENS, WHILE DACT1 WAS ALWAYS ESSENTIALLY UNMETHYLATED. HOWEVER, ALSO FOR THESE INHIBITORS, TREATMENT OF CELLS WITH THE DEMETHYLATING AGENT 5-AZA-2 -DEOXYCYTIDINE RESULTED IN AN INDUCTION OF THEIR EXPRESSION, AS SHOWN BY QUANTITATIVE PCR, SUGGESTING AN INDIRECT EPIGENETIC CONTROL OF ACTIVITY. WHILE THE DEGREE OF DEMETHYLATION AND ITS TRANSCRIPTIONAL CONSEQUENCES DIFFERED BETWEEN THE GENES, THERE WAS AN OVERALL HIGH CORRELATION OF DEMETHYLATION AND INCREASED ACTIVITY. PROTEIN EXPRESSION STUDIES REVEALED THAT NO CONSTITUTIVE WNT/BETA-CATENIN SIGNALLING OCCURRED IN THE CELL LINES, WHICH IS IN DISCREPANCY WITH RESULTS FROM PRIMARY CLL. HOWEVER, TREATMENT WITH 5-AZA-2 -DEOXYCYTIDINE CAUSED ACCUMULATION OF BETA-CATENIN. SIMULTANEOUSLY, E-CADHERIN EXPRESSION WAS STRONGLY INDUCED, LEADING TO THE FORMATION OF A COMPLEX WITH BETA-CATENIN AND THUS DEMONSTRATING ITS EPIGENETICALLY REGULATED INHIBITION EFFECT. CONCLUSIONS: THE RESULTS SUGGEST AN EPIGENETIC SILENCING MECHANISM OF THE WNT/BETA-CATENIN PATHWAY INHIBITOR GENES IN CLL. HYPERMETHYLATION AND SILENCING OF FUNCTIONALLY RELATED GENES MAY NOT BE COMPLETELY STOCHASTIC BUT RESULT FROM THE TUMOUR EPIGENOME REPROGRAMMING ORCHESTRATED BY POLYCOMB-GROUP REPRESSIVE COMPLEXES. THE DATA ARE OF INTEREST IN THE CONTEXT OF EPIGENETIC-BASED THERAPY. 2012