1 417 111 ANATOMIC SITE-SPECIFIC PATTERNS OF GENE COPY NUMBER GAINS IN SKIN, MUCOSAL, AND UVEAL MELANOMAS DETECTED BY FLUORESCENCE IN SITU HYBRIDIZATION. TO ASSESS THE DIFFERENCES BETWEEN MELANOMAS OF DIFFERENT LOCATION AND DIFFERENT ETIOLOGY, 372 MALIGNANT MELANOMAS WERE BROUGHT IN A TISSUE MICROARRAY FORMAT. THE COLLECTION INCLUDED 23 ACRAL AND 118 NON-ACRAL SKIN MELANOMAS, 9 MUCOSAL MELANOMAS, 100 UVEAL MELANOMAS, AND 122 MELANOMA METASTASES. FLUORESCENCE IN SITU HYBRIDIZATION (FISH) WAS USED TO ASSESS COPY NUMBER CHANGES OF THE CYCLIN D1 (CCND1), MDM2, C-MYC (MYC), AND HER2 GENES. FISH ANALYSIS REVEALED DISTINCT DIFFERENCES BETWEEN MELANOMAS FROM DIFFERENT LOCATIONS. CCND1 AMPLIFICATIONS WERE DETECTED IN SKIN MELANOMAS FROM SITES WITH CHRONIC SUN EXPOSURE (6 OF 32 CASES), ACRAL MELANOMAS (4 OF 17 CASES), AND MUCOSAL MELANOMAS (ONE OF TEN CASES) BUT NOT IN UVEAL MELANOMAS. HIGH-LEVEL MDM2 AMPLIFICATIONS WERE EXCLUSIVELY PRESENT IN ACRAL MELANOMAS (2 OF 19 CASES). MYC COPY NUMBER GAINS WERE DETECTED IN 32 OF 71 UVEAL MELANOMAS, FIVE OF EIGHT MUCOSAL MELANOMAS, AND 6 OF 67 MELANOMAS FROM SITES WITH INTERMITTENT SUN EXPOSURE BUT NOT IN ACRAL MELANOMAS NOR MELANOMAS FROM SITES WITH CHRONIC SUN EXPOSURE. ALTERATIONS OF THE MYC GENE WERE ASSOCIATED WITH ADVANCED TUMOR STAGE. THERE WERE NO HIGH-LEVEL HER2 AMPLIFICATIONS. SITE-SPECIFIC GENETIC AND EPIGENETIC FEATURES MAY IMPACT THE RESPONSE OF MELANOMAS TO VARIOUS ANTI-CANCER DRUGS AND SHOULD BE CONSIDERED IN FUTURE STUDIES ON THE MOLECULAR PATHOGENESIS OF MALIGNANT MELANOMAS. 2006 2 2135 31 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 3 59 26 A GENOME-WIDE SCREEN IDENTIFIES FREQUENTLY METHYLATED GENES IN HAEMATOLOGICAL AND EPITHELIAL CANCERS. BACKGROUND: GENETIC AS WELL AS EPIGENETIC ALTERATIONS ARE A HALLMARK OF BOTH EPITHELIAL AND HAEMATOLOGICAL MALIGNANCIES. HIGH THROUGHPUT SCREENS ARE REQUIRED TO IDENTIFY EPIGENETIC MARKERS THAT CAN BE USEFUL FOR DIAGNOSTIC AND PROGNOSTIC PURPOSES ACROSS MALIGNANCIES. RESULTS: HERE WE REPORT FOR THE FIRST TIME THE USE OF THE MIRA ASSAY (METHYLATED CPG ISLAND RECOVERY ASSAY) IN COMBINATION WITH GENOME-WIDE CPG ISLAND ARRAYS TO IDENTIFY EPIGENETIC MOLECULAR MARKERS IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) ON A GENOME-WIDE SCALE. WE IDENTIFIED 30 GENES DEMONSTRATING METHYLATION FREQUENCIES OF > OR =25% IN CHILDHOOD ALL, NINE GENES SHOWED SIGNIFICANTLY DIFFERENT METHYLATION FREQUENCIES IN B VS T-ALL. FOR MAJORITY OF THE GENES EXPRESSION COULD BE RESTORED IN METHYLATED LEUKEMIA LINES AFTER TREATMENT WITH 5-AZADC. FORTY-FOUR PERCENT OF THE GENES REPRESENT TARGETS OF THE POLYCOMB COMPLEX. IN CHRONIC MYELOID LEUKEMIA (CML) TWO OF THE GENES, (TFAP2A AND EBF2), DEMONSTRATED INCREASED METHYLATION IN BLAST CRISIS COMPARED TO CHRONIC PHASE (P < 0.05). FURTHERMORE HYPERMETHYLATION OF AN AUTOPHAGY RELATED GENE ATG16L2 WAS ASSOCIATED WITH POORER PROGNOSIS IN TERMS OF MOLECULAR RESPONSE TO IMATINIB TREATMENT. LASTLY WE DEMONSTRATED THAT TEN OF THESE GENES WERE ALSO FREQUENTLY METHYLATED IN COMMON EPITHELIAL CANCERS. CONCLUSION: IN SUMMARY WE HAVE IDENTIFIED A LARGE NUMBER OF GENES SHOWING FREQUENT METHYLATION IN CHILDHOOD ALL, METHYLATION STATUS OF TWO OF THESE GENES IS ASSOCIATED WITH ADVANCED DISEASE IN CML AND METHYLATION STATUS OF ANOTHER GENE IS ASSOCIATED WITH PROGNOSIS. IN ADDITION A SUBSET OF THESE GENES MAY ACT AS EPIGENETIC MARKERS ACROSS HEMATOLOGICAL MALIGNANCIES AS WELL AS COMMON EPITHELIAL CANCERS. 2010 4 6488 23 TP53 R72P POLYMORPHISM MODULATES DNA METHYLATION IN HEPATOCELLULAR CARCINOMA. BACKGROUND: HEPATOCELLULAR CARCINOMA (HCC) IS CHARACTERIZED BY WIDESPREAD EPIDEMIOLOGICAL AND MOLECULAR HETEROGENEITY. PREVIOUS WORK SHOWED THAT IN THE WESTERN PART OF NORTH AFRICA, A REGION OF LOW INCIDENCE OF HCC, MUTATIONS ARE SCARCE FOR THIS TUMOR TYPE. AS EPIGENETIC CHANGES ARE CONSIDERED POSSIBLE SURROGATES TO MUTATIONS IN HUMAN CANCERS, WE DECIDED, THUS, TO CHARACTERIZE DNA METHYLATION IN HCC FROM NORTH-AFRICAN PATIENTS. METHODS: A SET OF 11 LOCI WAS INVESTIGATED IN A SERIES OF 45 TUMOR SPECIMENS USING METHYLATION-SPECIFIC AND COMBINED-BISULFITE RESTRICTION ASSAY PCR. RESULTS OBTAINED ON CLINICAL SAMPLES WERE SUBSEQUENTLY VALIDATED IN LIVER CANCER CELL LINES. RESULTS: DNA METHYLATION AT TUMOR SUPPRESSOR LOCI IS SIGNIFICANTLY HIGHER IN SAMPLES DISPLAYING CHROMOSOME INSTABILITY. MORE IMPORTANTLY, DNA METHYLATION WAS SIGNIFICANTLY HIGHER IN ARG/ARG WHEN COMPARED TO PRO/PRO GENOTYPE CARRIERS AT CODON 72 RS1042522 OF TP53 (65% VS 20% METHYLATED LOCI, P = 0.0006), A POLYMORPHISM ALREADY KNOWN TO AFFECT SOMATIC MUTATION RATE IN HUMAN CARCINOMAS. IN VITRO EXPERIMENTS IN CELL LINES INDICATED THAT ENZYMES CONTROLLING DNA METHYLATION WERE DIFFERENTIALLY REGULATED BY CODON 72 ARG OR PRO ISOFORMS OF P53. FURTHERMORE, THE ARG72-CARRYING VERSION OF P53 WAS SHOWN TO RE-METHYLATE DNA MORE RAPIDLY THAN THE PRO-HARBORING ISOFORM. FINALLY, PRO-CARRYING CELL LINES WERE SHOWN TO BE SIGNIFICANTLY MORE RESISTANT TO DECITABINE TREATMENT (TWO-FOLD, P = 0.005). CONCLUSIONS: OUR DATA SUGGEST THAT ARG72PRO POLYMORPHISM IN A WT P53 CONTEXT MAY ACT AS A PRIMARY DRIVER OF EPIGENETIC CHANGES IN HCC. IT SUGGESTS, IN ADDITION, THAT RS1042522 GENOTYPE MAY PREDICT SENSITIVITY TO EPIGENETIC-TARGETED THERAPY. THIS MODEL OF LIVER TUMORIGENESIS THAT ASSOCIATES LOW PENETRANCE GENETIC PREDISPOSITION TO EPIGENETIC CHANGES EMERGES FROM A REGION OF LOW HCC INCIDENCE AND IT MAY, THEREFORE, APPLY ESSENTIALLY TO POPULATION LIVING IN SIMILAR AREAS. SURVEYS ON POPULATIONS SUBMITTED TO HIGHLY MUTAGENIC CONDITIONS AS PERINATALLY-ACQUIRED CHRONIC HEPATITIS B OR AFLATOXIN B1 EXPOSURE REMAINED TO BE CONDUCTED TO VALIDATE OUR OBSERVATIONS AS A GENERAL MODEL. 2015 5 3954 21 LONG INTERSPERSED NUCLEAR ELEMENT-1 METHYLATION STATUS IN THE CIRCULATING DNA FROM BLOOD OF PATIENTS WITH MALIGNANT AND CHRONIC INFLAMMATORY LUNG DISEASES. ALONG WITH OTHER MALIGNANT DISEASES, LUNG CANCER ARISES FROM THE PRECANCEROUS LUNG TISSUE STATE. ABERRANT DNA METHYLATION (HYPERMETHYLATION OF CERTAIN GENES AND HYPOMETHYLATION OF RETROTRANSPOSONS) IS KNOWN AS ONE OF THE DRIVING FORCES OF MALIGNANT CELL TRANSFORMATION. EPIGENETIC CHANGES WERE SHOWN TO BE DETECTABLE IN DNA, CIRCULATING IN THE BLOOD (CIRDNA) OF CANCER PATIENTS, INDICATING THE POSSIBILITY TO USE THEM AS CANCER MARKERS. THE CURRENT STUDY IS THE FIRST TO COMPARE THE LONG INTERSPERSED NUCLEAR ELEMENT-1 (LINE-1) METHYLATION LEVEL IN THE BLOOD FROM LUNG CANCER PATIENTS BEFORE TREATMENT VERSUS DIFFERENT CONTROL GROUPS AS HEALTHY SUBJECTS, PATIENTS WITH BRONCHITIS AND PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THE CONCENTRATION OF LINE-1 METHYLATED FRAGMENTS, REGION 1 (LINE-1 METHYLATED, LINE-1-MET) WAS ESTIMATED BY QUANTITATIVE METHYL-SPECIFIC PCR. THE TOTAL CONCENTRATION OF THE CIRCULATING LINE-1 COPIES WAS MEASURED BY QPCR SPECIFIC FOR LINE-1 REGION 2, WHICH WAS SELECTED DUE TO ITS CPG METHYLATION-INDEPENDENT SEQUENCE (LINE-1-IND). BOTH LINE-1 METHYLATION LEVEL AND LINE-1 METHYLATION INDEX (LINE-1-MET/LINE-1-IND RATIO) WAS DECREASED IN LUNG CANCER PATIENTS COMPARED WITH THE JOINT CONTROL GROUP (HEALTHY SUBJECTS + PATIENTS WITH BRONCHITIS + COPD PATIENTS) (MANN-WHITNEY U-TEST, P = 0.016). WE ALSO FOUND THAT THE TENDENCY OF LINE-1 METHYLATION INDEX DECREASES IN THE CIRDNA FROM LUNG CANCER PATIENTS VERSUS COPD PATIENTS (MANN-WHITNEY U-TEST, P = 0.07). OUR DATA INDICATE THAT THE QUANTITATIVE ANALYSIS OF THE LINE-1 METHYLATION LEVEL IN THE CIRDNA IS VALUABLE FOR DISCRIMINATION OF LUNG CANCER PATIENTS FROM PATIENTS WITH CHRONIC INFLAMMATORY LUNG DISEASES. 2021 6 1607 24 DNA METHYLATION, COLON CANCER AND MEDITERRANEAN DIET: RESULTS FROM THE EPIC-ITALY COHORT. THE BIOLOGICAL MECHANISMS THROUGH WHICH ADHERENCE TO MEDITERRANEAN DIET (MD) PROTECTS AGAINST COLON CANCER (CC) ARE POORLY UNDERSTOOD. EVIDENCE SUGGESTS THAT CHRONIC INFLAMMATION MAY BE IMPLICATED IN THE PATHWAY. BOTH DIET AND CC ARE RELATED TO EPIGENETIC REGULATION. WE PERFORMED A NESTED CASE-CONTROL STUDY ON 161 PAIRS FROM THE ITALIAN COMPONENT OF THE EUROPEAN PROSPECTIVE INVESTIGATION INTO CANCER AND NUTRITION (EPIC) COHORT, IN WHICH WE LOOKED FOR THE METHYLATION SIGNALS IN DNA EXTRACTED FROM LEUCOCYTES ASSOCIATED WITH BOTH CC AND MD IN 995 CPGS LOCATED IN 48 INFLAMMATION GENES. THE DNA METHYLATION SIGNALS DETECTED IN THIS ANALYSIS WERE VALIDATED IN A SUBGROUP OF 47 CASE-CONTROL PAIRS AND FURTHER REPLICATED (WHERE VALIDATED) IN 95 NEW PAIRS BY MEANS OF PYROSEQUENCING. AMONG THE CPG SITES SELECTED A-PRIORI IN INFLAMMATION-RELATED GENES, SEVEN CPG SITES WERE FOUND TO BE ASSOCIATED WITH CC STATUS AND WITH MD, IN LINE WITH ITS PROTECTIVE EFFECT. ONLY TWO CPG SITES (CG17968347-SERPINE1 AND CG20674490-RUNX3) WERE VALIDATED USING BISULPHITE PYROSEQUENCING AND, AFTER REPLICATION, WE FOUND THAT DNA METHYLATION OF CG20674490-RUNX3 MAY BE A POTENTIAL MOLECULAR MEDIATOR EXPLAINING THE PROTECTIVE EFFECT OF MD ON CC ONSET. THE USE OF A 'MEET-IN-THE-MIDDLE' APPROACH TO IDENTIFY THE OVERLAP BETWEEN EXPOSURE AND PREDICTIVE MARKERS OF DISEASE IS INNOVATIVE IN STUDIES ON THE RELATIONSHIP BETWEEN DIET AND CANCER, IN WHICH EXPOSURE ASSESSMENT IS DIFFICULT AND THE MECHANISMS THROUGH WHICH THE NUTRIENTS EXERT THEIR PROTECTIVE EFFECT IS LARGELY UNKNOWN. 2019 7 6845 25 [METHYLATION STATUS OF APOPTOSIS GENES AND INTENSITY OF APOPTOTIC DEATH OF PERIPHERAL BLOOD LYMPHOCYTES IN PERSONS CHRONICALLY EXPOSED TO RADIATION]. METHYLATION OF THE CPG ISLANDS OF GENE PROMOTER REGIONS IS THE MOST COMMON EPIGENETIC MODIFICATION INVOLVED IN THE REGULATION OF GENE EXPRESSION. A NUMBER OF STUDIES HAVE SHOWN THAT IONIZING RADIATION CAN CAUSE BOTH HYPER- AND HYPOMETHYLATION OF DNA. ABERRANT METHYLATION AFFECTS CELLULAR PROCESSES AND CAN LEAD TO THE DEVELOPMENT OF VARIOUS PATHOLOGICAL STATES. IN THE LITERATURE, THERE ARE FEW STUDIES ON THE METHYLATION STATUS OF HUMAN DNA A LONG TIME AFTER RADIATION EXPOSURE. HERE, THE METHYLATION LEVEL OF CPG ISLANDS OF THE PROMOTER REGIONS OF APOPTOSIS GENES (BCL2, ATM, MDM2, CDKN1A, STAT3, AND NFKB1), AND ALSO ITS INFLUENCE ON APOPTOSIS OF PERIPHERAL BLOOD LYMPHOCYTES IN CHRONICALLY EXPOSED PERSONS WERE STUDIED. RESIDENTS OF THE SOUTH URAL REGION WHO WERE CHRONICALLY EXPOSED TO RADIATION (AFTER DISCHARGES OF RADIOACTIVE WASTES INTO THE TECHA RIVER BY THE "MAYAK PRODUCTION ASSOCIATION" IN 1949-1956) WERE INCLUDED IN THE STUDY. IT WAS ESTABLISHED THAT THE PROPORTION OF INDIVIDUALS WITH HYPERMETHYLATED BCL2 GENE PROMOTER AMONG THE EXPOSED PEOPLE WAS STATISTICALLY SIGNIFICANTLY HIGHER THAN IN THE CONTROL GROUP. THE PERCENTAGE OF METHYLATION OF THE ATM GENE PROMOTER WEAKLY POSITIVELY CORRELATED WITH DOSE AND AGE CHARACTERISTICS. DIFFERENCES IN THE FREQUENCY OF LYMPHOCYTE APOPTOSIS IN EXPOSED INDIVIDUALS WITH A HYPO- OR HYPERMETHYLATED ATM GENE PROMOTER WERE ALSO ESTABLISHED. THE DATA INDICATE THAT, IN THE LONG-TERM, AFTER CHRONIC LOW INTENSITY RADIATION EXPOSURE AT LOW AND MEDIUM DOSES, EPIGENETIC MODIFICATIONS OF THE GENOME OCCUR, WHICH ARE MANIFESTED AS CHANGES IN METHYLATION OF PROMOTER REGIONS OF BCL2 AND ATM GENES. 2022 8 2908 25 GENE EXPRESSION PROFILE OF NORMAL BREAST TISSUE AND BODY MASS INDEX. BACKGROUND: IN HUMAN BREAST, ADIPOSE TISSUE REPRESENTS UP TO 80% OF THE TOTAL VOLUME AND PLAYS A CRITICAL ROLE IN MAMMARY GLAND REMODELING. GIVEN THE EMERGING ROLE OF OBESITY IN BREAST CANCER GROWTH AND DEVELOPMENT, WE EXPLORED THE RELATIONSHIP BETWEEN BODY MASS INDEX (BMI), AS A PROXY OF WOMAN'S OBESITY STATUS, AND THE EXPRESSION IN NORMAL BREAST TISSUE FROM HEALTHY WOMEN OF A SELECTED PANEL OF GENES, KNOWN TO BE INVOLVED IN MAMMARY GLAND HOMEOSTASIS. METHODS: TWO INDEPENDENT PUBLICLY AVAILABLE DATASETS, COMPOSED OF 180 SPECIMENS OF NORMAL BREAST TISSUE FROM REDUCTION MAMMOPLASTY WERE INTERROGATED. DIFFERENTIAL GENE EXPRESSION AMONG BMI CLASSES WAS EVALUATED BY ANOVA, AND PARTIAL CORRELATION COEFFICIENT WAS USED TO ASSAY THE CORRELATION BETWEEN GENES CONTROLLING FOR BMI. RESULTS: DESPITE THE DIFFERENCES IN MICROARRAY PLATFORMS AND ANALYTICAL PROCEDURES, THE TWO DATASETS SHARED A CORE OF 9 GENES DIFFERENTIALLY EXPRESSED IN BMI CLASSES AND SIGNIFICANTLY CORRELATED WITH BMI. FOUR (44%) OF THESE GENES BELONG TO THE FUNCTIONAL CLASS OF CYTOKINES AND CYTOKINE RECEPTORS (IL1R1, IL2RA, IL12A, AND IL12RB2). THE OTHERS BELONG TO THE FUNCTIONAL CLASS OF THE EPIGENETIC REGULATION (MEDAG AND SETD7), SIGNAL TRANSDUCTION (STAT1), CELL ADHESION (ITGAV), AND ENZYMATIC ACTIVITY (STS). CONCLUSIONS: ALTHOUGH EXPLORATORY, PRESENT FINDINGS ARE IN AGREEMENT WITH THE ROLE OF INFLAMMATION MODULATORS IN THE HOMEOSTASIS OF NORMAL BREAST TISSUE AND THE BELIEVE THAT AN INCREASE IN BODY ADIPOSE TISSUE MAY HAVE A POTENTIALLY DANGEROUS LOCAL EFFECT, THROUGH THE INCREASED EXPRESSION OF INFLAMMATION-RELATED GENES AND THE ESTABLISHMENT OF A LOW-GRADE CHRONIC INFLAMMATION. 2021 9 3588 35 IMPACT OF TP53 GENE PROMOTER METHYLATION ON CHRONIC LYMPHOCYTIC LEUKEMIA PATHOGENESIS AND PROGRESSION. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS A MALIGNANT LYMPHOID DISORDER THAT RESULTS FROM THE OVERGROWTH OF MATURE-LOOKING LYMPHOID CELLS IN THE BLOOD AND LYMPHATIC TISSUE. VARIOUS CLINICAL PRESENTATIONS HAVE BEEN ATTRIBUTED TO THE DISEASE AS A RESULT OF THE DIFFERENT UNDERLYING GENETIC AND EPIGENETIC ALTERATIONS. THE CURRENT STUDY HAS BEEN INITIATED TO STUDY THE ROLE OF AN EPIGENETIC ALTERATION AFFECTING THE PROMOTER OF THE TP53GENE ON CLL PATHOGENESIS AND PROGRESSION. METHODS: THE CURRENT STUDY INVOLVED 54 NEWLY DIAGNOSED PATIENTS PRESENTING WITH CLL AS WELL AS 30 NORMAL INDIVIDUALS AS CONTROLS. AFTER OBTAINING VERBAL CONSENT, DATA COLLECTION WAS DONE AND THE BLOOD COLLECTED FROM ALL ENROLLED INDIVIDUALS FOR HEMATOLOGICAL INVESTIGATIONS AS WELL AS FOR MOLECULAR CATEGORIZATION OF TP53 METHYLATION STATUS. METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MS-PCR) TECHNIQUE WAS USED TO DEFINE THE METHYLATION STATUS OF THE TP53 GENE PROMOTER THAT ENCOMPASSES DNA EXTRACTION, BISULFITE CONVERSION, CONVENTIONAL PCR AMPLIFICATION, RUNNING ON AGAROSE GEL AND DOCUMENTATION. FINALLY, STATISTICAL ANALYSIS WAS DONE TO ASSESS ANY CORRELATION OF THE TP53 EPIGENETIC ALTERATION TO THE DISEASE ETIOLOGY AND THE PROGRESSION. RESULTS: IN THE CURRENT STUDY, ALL CONTROLS AND 42 OF 54 PATIENTS SHOW UNMETHYLATED TP53 GENE PROMOTER; ON THE OTHER HAND, THE METHYLATED PROMOTER WAS DETECTED AMONG 12 PATIENTS WITH A P-VALUE OF 0.001. TP53 GENE PROMOTER METHYLATION SIGNIFICANTLY LINKED TO REDUCED PLATELET COUNT (P-VALUE OF 0.047) AND ADVANCED STAGE AT PRESENTATION (P-VALUE OF 0.076). NO SIGNIFICANT DIFFERENCES WERE SEEN AMONG BOTH METHYLATED AND UNMETHYLATED TP53 PROMOTERS IN RELATION TO THE AGE OF THE AFFECTED INDIVIDUALS, TOTAL WHITE BLOOD CELL COUNTS AND HEMOGLOBIN LEVEL OF THE AFFECTED INDIVIDUALS. CONCLUSION: THE CURRENT STUDY REVEALED A SIGNIFICANT CORRELATION OF TP53 GENE PROMOTER METHYLATION TO CHRONIC LYMPHOCYTIC LEUKEMIA PATHOGENESIS AND LOWER PLATELET COUNTS. 2019 10 839 17 CHEMO-ENZYMATIC FLUORESCENCE LABELING OF GENOMIC DNA FOR SIMULTANEOUS DETECTION OF GLOBAL 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE. 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE ARE EPIGENETIC MODIFICATIONS INVOLVED IN GENE REGULATION AND CANCER. WE PRESENT A NEW, SIMPLE, AND HIGH-THROUGHPUT PLATFORM FOR MULTI-COLOR EPIGENETIC ANALYSIS. THE NOVELTY OF OUR APPROACH IS THE ABILITY TO MULTIPLEX METHYLATION AND DE-METHYLATION SIGNALS IN THE SAME ASSAY. WE UTILIZE AN ENGINEERED METHYLTRANSFERASE ENZYME THAT RECOGNIZES AND LABELS ALL UNMODIFIED CPG SITES WITH A FLUORESCENT COFACTOR. IN COMBINATION WITH THE ALREADY ESTABLISHED LABELING OF THE DE-METHYLATION MARK 5-HYDROXYMETHYLCYTOSINE VIA ENZYMATIC GLYCOSYLATION, WE OBTAINED A ROBUST PLATFORM FOR SIMULTANEOUS EPIGENETIC ANALYSIS OF THESE MARKS. WE ASSESSED THE GLOBAL EPIGENETIC LEVELS IN MULTIPLE SAMPLES OF COLORECTAL CANCER AND OBSERVED A 3.5-FOLD REDUCTION IN 5HMC LEVELS BUT NO CHANGE IN DNA METHYLATION LEVELS BETWEEN SICK AND HEALTHY INDIVIDUALS. WE ALSO MEASURED EPIGENETIC MODIFICATIONS IN CHRONIC LYMPHOCYTIC LEUKEMIA AND OBSERVED A DECREASE IN BOTH MODIFICATION LEVELS (5-HYDROXYMETHYLCYTOSINE: WHOLE BLOOD 30 %; PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) 40 %. 5-METHYLCYTOSINE: WHOLE BLOOD 53 %; PBMCS 48 %). OUR FINDINGS PROPOSE USING A SIMPLE BLOOD TEST AS A VIABLE METHOD FOR ANALYSIS, SIMPLIFYING SAMPLE HANDLING IN DIAGNOSTICS. IMPORTANTLY, OUR RESULTS HIGHLIGHT THE ASSAY'S POTENTIAL FOR EPIGENETIC EVALUATION OF CLINICAL SAMPLES, BENEFITING RESEARCH AND PATIENT MANAGEMENT. 2023 11 2048 23 EPIGENETIC CLUSTERING OF LUNG ADENOCARCINOMAS BASED ON DNA METHYLATION PROFILES IN ADJACENT LUNG TISSUE: ITS CORRELATION WITH SMOKING HISTORY AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. THE AIM OF THIS STUDY WAS TO CLARIFY THE SIGNIFICANCE OF DNA METHYLATION ALTERATIONS DURING LUNG CARCINOGENESIS. INFINIUM ASSAY WAS PERFORMED USING 139 PAIRED SAMPLES OF NON-CANCEROUS LUNG TISSUE (N) AND TUMOROUS TISSUE (T) FROM A LEARNING COHORT OF PATIENTS WITH LUNG ADENOCARCINOMAS (LADCS). FIFTY PAIRED N AND T SAMPLES FROM A VALIDATION COHORT WERE ALSO ANALYZED. DNA METHYLATION ALTERATIONS ON 1,928 PROBES OCCURRED IN N SAMPLES RELATIVE TO NORMAL LUNG TISSUE FROM PATIENTS WITHOUT PRIMARY LUNG TUMORS, AND WERE INHERITED BY, OR STRENGTHENED IN, T SAMPLES. UNSUPERVISED HIERARCHICAL CLUSTERING USING DNA METHYLATION LEVELS IN N SAMPLES ON ALL 26,447 PROBES SUBCLUSTERED PATIENTS INTO CLUSTER I (N = 32), CLUSTER II (N = 35) AND CLUSTER III (N = 72). LADCS IN CLUSTER I DEVELOPED FROM THE INFLAMMATORY BACKGROUND IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IN HEAVY SMOKERS AND WERE LOCALLY INVASIVE. MOST PATIENTS IN CLUSTER II WERE NON-SMOKERS AND HAD A FAVORABLE OUTCOME. LADCS IN CLUSTER III DEVELOPED IN LIGHT SMOKERS WERE MOST AGGRESSIVE (FREQUENTLY SHOWING LYMPHATIC AND BLOOD VESSEL INVASION, LYMPH NODE METASTASIS AND AN ADVANCED PATHOLOGICAL STAGE), AND HAD A POOR OUTCOME. DNA METHYLATION LEVELS OF HALLMARK GENES FOR EACH CLUSTER, SUCH AS IRX2, HOXD8, SPARCL1, RGS5 AND EI24, WERE AGAIN CORRELATED WITH CLINICOPATHOLOGICAL CHARACTERISTICS IN THE VALIDATION COHORT. DNA METHYLATION PROFILES REFLECTING CARCINOGENETIC FACTORS SUCH AS SMOKING AND COPD APPEAR TO BE ESTABLISHED IN NON-CANCEROUS LUNG TISSUE FROM PATIENTS WITH LADCS AND MAY DETERMINE THE AGGRESSIVENESS OF TUMORS DEVELOPING IN INDIVIDUAL PATIENTS, AND THUS PATIENT OUTCOME. 2014 12 1345 26 DETECTION OF DIFFERENTIALLY METHYLATED REGIONS USING BAYES FACTOR FOR ORDINAL GROUP RESPONSES. RESEARCHERS IN GENOMICS ARE INCREASINGLY INTERESTED IN EPIGENETIC FACTORS SUCH AS DNA METHYLATION, BECAUSE THEY PLAY AN IMPORTANT ROLE IN REGULATING GENE EXPRESSION WITHOUT CHANGES IN THE DNA SEQUENCE. THERE HAVE BEEN SIGNIFICANT ADVANCES IN DEVELOPING STATISTICAL METHODS TO DETECT DIFFERENTIALLY METHYLATED REGIONS (DMRS) ASSOCIATED WITH BINARY DISEASE STATUS. MOST OF THESE METHODS ARE BEING DEVELOPED FOR DETECTING DIFFERENTIAL METHYLATION RATES BETWEEN CASES AND CONTROLS. WE CONSIDER MULTIPLE SEVERITY LEVELS OF DISEASE, AND DEVELOP A BAYESIAN STATISTICAL METHOD TO DETECT THE REGION WITH INCREASING (OR DECREASING) METHYLATION RATES AS THE DISEASE SEVERITY INCREASES. PATIENTS ARE CLASSIFIED INTO MORE THAN TWO GROUPS, BASED ON THE DISEASE SEVERITY (E.G., STAGES OF CANCER), AND DMRS ARE DETECTED BY USING MOVING WINDOWS ALONG THE GENOME. WITHIN EACH WINDOW, THE BAYES FACTOR IS CALCULATED TO TEST THE HYPOTHESIS OF MONOTONIC INCREASE IN METHYLATION RATES CORRESPONDING TO SEVERITY OF THE DISEASE VERSUS NO DIFFERENCE. A MIXED-EFFECT MODEL IS USED TO INCORPORATE THE CORRELATION OF METHYLATION RATES OF NEARBY CPG SITES IN THE REGION. RESULTS FROM EXTENSIVE SIMULATION INDICATE THAT OUR PROPOSED METHOD IS STATISTICALLY VALID AND REASONABLY POWERFUL. WE DEMONSTRATE OUR APPROACH ON A BISULFITE SEQUENCING DATASET FROM A CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) STUDY. 2019 13 3897 27 LARGE-SCALE ANALYSIS OF THE GENETIC AND EPIGENETIC ALTERATIONS IN HEPATOCELLULAR CARCINOMA FROM SOUTHEAST CHINA. OUR KNOWLEDGE ABOUT MOLECULAR ALTERATIONS DURING HEPATOCARCINOGENESIS IS STILL FRAGMENTARY, DUE TO LACK OF COMPREHENSIVE GENETIC AND EPIGENETIC ANALYSES IN THE SAME SET OF HEPATOCELLULAR CARCINOMAS (HCCS). IN THIS STUDY, WE CONDUCTED A LARGE-SCALE ANALYSIS, INCLUDING MUTATION SCREENING IN 50 GENES AND METHYLATION ASSAYS IN THREE GENES IN 54 PAIRS OF HCCS AND THEIR NEIGHBORING NON-CANCEROUS TISSUES. ALL SAMPLES WERE COLLECTED FROM THE RESIDENTS IN SOUTHEAST CHINA. WE FOUND HBV INFECTION AND CHRONIC HEPATITIS/CIRRHOSIS IN 83.3% AND 98.1% OF THE CASES, RESPECTIVELY. MUTATIONS WERE IDENTIFIED IN 18 OUT OF 54 (33.3%) SAMPLES, WITH P53 ALTERATIONS IN 14 CASES AND BETA-CATENIN MUTATIONS IN FOUR TUMORS. NO MUTATIONS WERE IDENTIFIED IN THE NEIGHBORING TISSUES. INTERESTINGLY, 9 OUT OF 14 (64.3%) TUMORS CARRYING P53 MUTATIONS DISPLAYED SUBSTITUTION OF SERINE BY ARGININE AT CODON 249, A CHARACTERISTIC CHANGE BELIEVED TO BE INDUCED BY AFLATOXIN-B1. FURTHERMORE, P53 MUTATION WAS SIGNIFICANTLY ASSOCIATED WITH SHORTER RECURRENCE-FREE SURVIVAL (P=0.004). THE RESULTS ALSO REVEALED ABERRANT METHYLATION IN TWO OR MORE GENES IN AS HIGH AS 90% OF TUMORS AND 40% OF ADJACENT TISSUES. THE FREQUENCY OF RASSF1A HYPERMETHYLATION WAS MUCH HIGHER THAN THAT OF P16INK4A AND HAI2 IN BOTH HCC AND NEIGHBORING TISSUES, INDICATING THAT DEREGULATION OF RASSF1A MAY PRECEDE THE OTHER TWO GENES. THESE DATA SUGGEST THAT ABERRANT METHYLATION OCCURS BEFORE MUTATION AND IS AN EARLY EVENT IN THE DEVELOPMENT OF THIS SET OF HCC. OUR FINDINGS HIGHLIGHT P53 AS A PROGNOSTIC FACTOR OF HCC AND RASSF1A AS A POTENTIAL TARGET IN PREVENTING MALIGNANT TRANSFORMATION OF HEPATOCYTES. 2008 14 5304 19 PROTEOMIC ANALYSIS OF INFLAMMATORY BIOMARKERS ASSOCIATED WITH BREAST CANCER RECURRENCE. INTRODUCTION: BREAST CANCER IS THE MOST FREQUENT CANCER DETECTED FOR WOMEN, AND WHILE OUR ABILITY TO TREAT BREAST CANCER HAS IMPROVED SUBSTANTIALLY OVER THE YEARS, RECURRENCE REMAINS A MAJOR OBSTACLE. STANDARD SCREENING FOR NEW AND RECURRENT BREAST CANCER INVOLVES CLINICAL BREAST IMAGING. HOWEVER, THERE IS NO CLINICALLY APPROVED NONINVASIVE BODY FLUID TEST FOR THE EARLY DETECTION OF RECURRENT BREAST CANCER. MATERIALS AND METHOD: IN THIS STUDY, WE ANALYZED SERUM SAMPLES FROM BOTH RECURRENT AND NONRECURRENT BREAST CANCER PATIENTS BY DIFFERENT PROTEOMICS METHODS TO IDENTIFY BIOMARKERS IN PATIENTS WITH RECURRENCE OF DISEASE. RESULTS: COMPARATIVE DATA ANALYSIS IDENTIFIED SEVERAL HISTONE DEACETYLASE (HDAC) PROTEINS, WHICH WERE FOUND AT SIGNIFICANTLY HIGHER LEVELS IN THE SERUM OF RECURRENT BREAST CANCER PATIENTS: HDAC9 (C-TERM) (P = 0.0035), HDAC5 (C-TERM) (P = 0.013), SMALL UBIQUITIN-LIKE MODIFIER 1 (N-TERM) (P = 0.017), EMBRYONIC STEM CELL-EXPRESSED RAS (INTER) (P = 0.018), AND HDAC7 (C-TERM) (P = 0.020). CHRONIC INFLAMMATION PLAYS A CRITICAL ROLE IN THE DEVELOPMENT OF THE BREAST CANCER RECURRENCE, AND WE IDENTIFIED SEVERAL PROINFLAMMATORY CYTOKINES THAT WERE PRESENT AT ELEVATED LEVELS ONLY IN RECURRENT BREAST CANCER PATIENT SERUM. CONCLUSIONS: OUR DATA INDICATED THAT THE EPIGENETIC REGULATION OF INFLAMMATORY PROCESSES PLAYS A CRITICAL ROLE IN BREAST CANCER RECURRENCE. THE IDENTIFIED PROTEINS COULD LAY THE GROUNDWORK FOR THE DEVELOPMENT OF A SERUM-BASED BREAST CANCER RECURRENCE ASSAY. 2020 15 3248 23 HEPATITIS B VIRUS GENOME ASYMMETRY IN HEPATOCELLULAR CARCINOMA. BACKGROUND: THE ASSOCIATION BETWEEN HEPATITIS B VIRUS (HBV) MUTATIONS AND HEPATOCARCINOGENESIS WERE REPORTED IN THE LITERATURE. PREFERENCE FOR G OVER C IN THE LEADING DNA STRAND HAS BEEN REPORTED TO ACCOUNT FOR THE ASYMMETRY IN NUCLEOTIDE (NT) COMPOSITION. THE AIM OF THIS STUDY WAS TO ANALYZE THE COMPLETE GENOME SEQUENCE AND COMPOSITIONAL ASYMMETRY OF HBV IN DIFFERENT STAGES OF HEPATITIS B. METHODS: FULL GENOME SEQUENCING OF 24 PATIENTS WITH CHRONIC HEPATITIS B, SOME OF WHOM ALSO HAD CIRRHOSIS AND HEPATOCELLULAR CARCINOMA (HCC) WAS PERFORMED. MUTATIONS ANALYSIS WAS IMPLEMENTED IN A COMPARISON WITH A HBV GENOTYPE D REFERENCE FROM AN INTERNATIONAL DNA DATABASE. CPGPROD, A WEB-BASED APPLICATION, WAS USED TO EVALUATE CG CONTENT AND PREDICT CPG ISLANDS. RESULTS: ALL STRAINS WERE 3182 BASE PAIRS (BP) IN LENGTH, EXCEPT FOR TWO CASES OF HCC IN WHICH 9 AND 21 NT, RESPECTIVELY, WERE DELETED IN PRES2. THE GENETIC RELATEDNESS OF THESE ISOLATES WAS 97%-100%. THERE WERE COMMON CPG-RICH REGIONS IN ALL 24 ISOLATED FULL GENOME SEQUENCES, HOWEVER A STRONG NEGATIVE GC SKEW FOR FORMING A CPG ISLAND IN THE MINUS STRAND WERE EXHIBITED IN OVERLAP WITH ENHANCER I IN THREE HCC PATIENTS, A CIRRHOTIC PATIENT AND THREE WITH CHRONIC HEPATITIS. CONCLUSION: THE HIGH PERCENTAGE OF SEQUENCE IDENTITY BETWEEN HBV ISOLATES IN OUR PATIENTS DEMONSTRATES THAT GENOMIC FACTORS, EXCEPT FOR GENOTYPE, ARE INVOLVED IN HEPATOCARCINOGENESIS. VARIATIONS IN GC CONTENT WHICH WERE CAUSED BY A DIFFERENT SPECTRUM OF MUTATIONS MAY AFFECT DNA COMPOSITIONAL ASYMMETRY AND EPIGENETIC MODIFICATION OF HBV DNA IN HCC. 2012 16 1805 21 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 17 864 27 CHROMOSOMAL INSTABILITY IN ORAL SQUAMOUS CELL CARCINOMA. ORAL SQUAMOUS CELL CARCINOMA (OSCC) DEMONSTRATES AN INCREASING RATE DUE TO HIGH RISK HUMAN PAPILLOMA VIRUS (HR-HPV) PERSISTENT INFECTION, AND ALSO TO CHRONIC CIGARETTE AND ALCOHOL CONSUMPTION. GROSS CHROMOSOMAL ALTERATIONS (POLYSOMY, ANEUPLOIDY, INTRA-CHROMOSOME REARRANGEMENTS) AND SPECIFIC GENE ABERRATIONS SUCH AS AMPLIFICATIONS, DELETIONS, POINT MUTATIONS COMBINED OR NOT WITH EPIGENETIC ONES (PROMOTER METHYLATIONS AND MIRNA DEREGULATIONS) ARE RESPONSIBLE FOR THE PROGRESSIVE TRANSFORMATION OF NORMAL SQUAMOUS CELL EPITHELIA TO THE CORRESPONDING MALIGNANT. CHROMOSOMAL INSTABILITY (CI) -BASED ON STRUCTURAL OR NUMERICAL ABNORMALITIES- LEADS TO SPECIFIC ABNORMAL KARYOTYPES COMBINED OR NOT WITH FUNCTIONAL SUPPRESSOR GENE INACTIVATION AND ONCOGENE OVERACTIVATION IN SOLID MALIGNANCIES, INCLUDING OSCC. EXTENSIVE CYTOGENETIC ANALYSES HAVE SHOWN THAT GROSS ALTERATIONS (GAINS/LOSSES) IN CHROMOSOMES 3, 4, 7, 8, 9, 11, 14, 17, 18, 19 AND ALSO 20 FORM DIFFERENT CI PATTERNS IN OSCC, WHICH IN CONJUNCTION WITH AN AGGRESSIVE PHENOTYPE (PRESENCE OF LYMPH NODAL METASTASIS) NEGATIVELY AFFECT THE PROGNOSIS IN THE CORRESPONDING PATIENTS. IN THE MAJORITY OF OSCC CASES, LOSS OF CHROMOSOMAL BANDS ARE ALMOST EQUALLY DETECTED COMPARED WITH GAINS REGARDING THE CHROMOSOMES REFERRED ABOVE. IN THE CURRENT SPECIAL MOLECULAR PAPER WE EXPLORED THE ROLE OF CI IN THE PROGRESSION AND BIOLOGICAL BEHAVIOR OF OSCCS. 2018 18 6684 18 VALIDATION OF AN LC-MS BASED APPROACH FOR PROFILING HISTONES IN CHRONIC LYMPHOCYTIC LEUKEMIA. THE IN VITRO EVALUATION OF HISTONES AND THEIR PTMS HAS DRAWN SUBSTANTIAL INTEREST IN THE DEVELOPMENT OF EPIGENETIC THERAPIES. THE DIFFERENTIAL EXPRESSION OF HISTONE ISOFORMS MAY SERVE AS A POTENTIAL MARKER IN THE CLASSIFICATION OF DISEASES AFFECTED BY CHROMATIN ABNORMALITIES. IN THIS STUDY, PROTEIN PROFILING BY LC AND MS WAS USED TO EXPLORE DIFFERENCES IN HISTONE COMPOSITION IN PRIMARY CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS. EXTENSIVE METHOD VALIDATIONS WERE PERFORMED TO DETERMINE THE EXPERIMENTAL VARIANCES THAT WOULD IMPACT HISTONE RELATIVE ABUNDANCE. THE RESULTING DATA DEMONSTRATED THAT THE PROPOSED METHODOLOGY WAS SUITABLE FOR THE ANALYSIS OF HISTONE PROFILES. IN 4 NORMAL INDIVIDUALS AND 40 CLL PATIENTS, A SIGNIFICANT DECREASE IN THE RELATIVE ABUNDANCE OF HISTONE H2A VARIANTS (H2AFL AND H2AFA/M*) WAS OBSERVED IN PRIMARY CLL CELLS AS COMPARED TO NORMAL B CELLS. PROTEIN IDENTITIES WERE DETERMINED USING HIGH MASS ACCURACY MS AND SHOTGUN PROTEOMICS. 2009 19 1739 28 EARLY DNA METHYLATION CHANGES IN CHILDREN DEVELOPING BETA CELL AUTOIMMUNITY AT A YOUNG AGE. AIMS/HYPOTHESIS: TYPE 1 DIABETES IS A CHRONIC AUTOIMMUNE DISEASE OF COMPLEX AETIOLOGY, INCLUDING A POTENTIAL ROLE FOR EPIGENETIC REGULATION. PREVIOUS EPIGENOMIC STUDIES FOCUSED MAINLY ON CLINICALLY DIAGNOSED INDIVIDUALS. THE AIM OF THE STUDY WAS TO ASSESS EARLY DNA METHYLATION CHANGES ASSOCIATED WITH TYPE 1 DIABETES ALREADY BEFORE THE DIAGNOSIS OR EVEN BEFORE THE APPEARANCE OF AUTOANTIBODIES. METHODS: REDUCED REPRESENTATION BISULPHITE SEQUENCING (RRBS) WAS APPLIED TO STUDY DNA METHYLATION IN PURIFIED CD4(+) T CELL, CD8(+) T CELL AND CD4(-)CD8(-) CELL FRACTIONS OF 226 PERIPHERAL BLOOD MONONUCLEAR CELL SAMPLES LONGITUDINALLY COLLECTED FROM SEVEN TYPE 1 DIABETES-SPECIFIC AUTOANTIBODY-POSITIVE INDIVIDUALS AND CONTROL INDIVIDUALS MATCHED FOR AGE, SEX, HLA RISK AND PLACE OF BIRTH. WE ALSO EXPLORED CORRELATIONS BETWEEN DNA METHYLATION AND GENE EXPRESSION USING RNA SEQUENCING DATA FROM THE SAME SAMPLES. TECHNICAL VALIDATION OF RRBS RESULTS WAS PERFORMED USING PYROSEQUENCING. RESULTS: WE IDENTIFIED 79, 56 AND 45 DIFFERENTIALLY METHYLATED REGIONS IN CD4(+) T CELLS, CD8(+) T CELLS AND CD4(-)CD8(-) CELL FRACTIONS, RESPECTIVELY, BETWEEN TYPE 1 DIABETES-SPECIFIC AUTOANTIBODY-POSITIVE INDIVIDUALS AND CONTROL PARTICIPANTS. THE ANALYSIS OF PRE-SEROCONVERSION SAMPLES IDENTIFIED DNA METHYLATION SIGNATURES AT THE VERY EARLY STAGE OF DISEASE, INCLUDING DIFFERENTIAL METHYLATION AT THE PROMOTER OF IRF5 IN CD4(+) T CELLS. FURTHER, WE VALIDATED RRBS RESULTS USING PYROSEQUENCING AT THE FOLLOWING CPG SITES: CHR19:18118304 IN THE PROMOTER OF ARRDC2; CHR21:47307815 IN THE INTRON OF PCBP3; AND CHR14:81128398 IN THE INTERGENIC REGION NEAR TRAF3 IN CD4(+) T CELLS. CONCLUSIONS/INTERPRETATION: THESE PRELIMINARY RESULTS PROVIDE NOVEL INSIGHTS INTO CELL TYPE-SPECIFIC DIFFERENTIAL EPIGENETIC REGULATION OF GENES, WHICH MAY CONTRIBUTE TO TYPE 1 DIABETES PATHOGENESIS AT THE VERY EARLY STAGE OF DISEASE DEVELOPMENT. SHOULD THESE FINDINGS BE VALIDATED, THEY MAY SERVE AS A POTENTIAL SIGNATURE USEFUL FOR DISEASE PREDICTION AND MANAGEMENT. 2022 20 1424 24 DIFFERENTIAL DNA METHYLATION OF GENE PROMOTERS IN SMALL B-CELL LYMPHOMAS. IMPROVED CARE OF PATIENTS WITH SMALL B-CELL LYMPHOMAS (SBCLS) IS LIKELY TO RESULT FROM THE ONGOING DISCOVERY OF MOLECULAR MARKERS THAT BETTER DEFINE THESE MALIGNANT NEOPLASMS. WE IDENTIFIED MULTIPLE GENE LOCI WHOSE DNA METHYLATION PATTERNS DIFFERED BETWEEN 3 TYPES OF SBCL: B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA/SMALL LYMPHOCYTIC LYMPHOMA, MANTLE CELL LYMPHOMA, AND GRADES I AND II FOLLICULAR LYMPHOMA. THIS ANALYSIS WAS PERFORMED USING AN OLIGONUCLEOTIDE MICROARRAY THAT ALLOWED DETERMINATION OF THE DNA METHYLATION STATUS OF 156 LOCI IN 38 GENES. COMBINED BISULFITE RESTRICTION ANALYSIS AND METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION WERE USED TO VALIDATE THE DIFFERENTIAL METHYLATION OF 6 OF THESE GENES. BY USING NON-HODGKIN LYMPHOMA CELL LINES AS MODELS, THESE GENES WERE EXAMINED FURTHER FOR METHYLATION AND GENE EXPRESSION RELATIONSHIPS. THIS STUDY ILLUSTRATES NONRANDOM EPIGENETIC ALTERATIONS IN SBCLS THAT SEEM TO PREFERENTIALLY INVOLVE LYMPHOMAS OF GERMINAL CENTER DERIVATION. 2005