1 3030 125 GENETICS OF OPISTHORCHIS VIVERRINI-RELATED CHOLANGIOCARCINOMA. PURPOSE OF REVIEW: WE REVIEW THE GENETIC, EPIGENETIC AND TRANSCRIPTIONAL LANDSCAPE OF LIVER FLUKE (OPISTHORCHIS VIVERRINI, OV)-RELATED CHOLANGIOCARCINOMA (CCA). ITS DISTINCT ALTERATIONS, AS COMPARED WITH NON-OV-RELATED CCA MAY HELP SHED LIGHT ON ITS UNDERLYING MOLECULAR MECHANISMS. RECENT FINDINGS: RECENT WHOLE-EXOME AND TARGETED SEQUENCING NOT ONLY CONFIRMED FREQUENT MUTATIONS IN KNOWN CCA-RELATED GENES INCLUDING TP53 (44%), KRAS (16.7%) AND SMAD4 (16.7%), BUT ALSO REVEALED MUTATIONS IN NOVEL CCA-RELATED GENES ASSOCIATED WITH CHROMATIN REMODELING [BAP1 (2.8%), ARID1A (17.6%), MLL3 (13%) AND IDH1/2 (2.8%)], WNT SIGNALING [RNF43 (9.3%) AND PEG3 (5.6%)] AND KRAS/G PROTEIN SIGNALING [GNAS (9.3%) AND ROBO2 (9.3%)]. INTERESTINGLY, THERE IS A SIGNIFICANT DIFFERENCE IN THE FREQUENCY OF MUTATED GENES BETWEEN OV-RELATED CCA AND NON-OV-RELATED CCA, SUCH AS P53 AND IDH1/2, REFLECTING THE IMPACT OF CAUSE ON PATHOGENESIS. ALTERED DNA METHYLATION AND TRANSCRIPTIONAL PROFILES ASSOCIATED WITH XENOBIOTIC METABOLISM AND PRO-INFLAMMATORY RESPONSES WERE ALSO FOUND IN OV-RELATED CCA. SUMMARY: LIVER FLUKE-INDUCED CHRONIC INFLAMMATION PLAYS A CRUCIAL ROLE IN CHOLANGIOCARCINOGENESIS, RESULTING IN DISTINCT SIGNATURES OF GENETIC, EPIGENETIC AND TRANSCRIPTIONAL ALTERATIONS. THESE ALTERATIONS, WHEN CONTRASTED WITH NON-OV-RELATED CCA, INDICATE A UNIQUE PATHOGENIC PROCESS IN OV-RELATED CCA AND MAY HAVE POTENTIAL CLINICAL IMPLICATIONS ON DIAGNOSTICS, THERAPEUTICS AND PREVENTION. 2015 2 2974 27 GENETIC AND METHYLATION STATUS OF CDKN2A (P14(ARF)/P16(INK4A)) AND TP53 GENES IN RECURRENT RESPIRATORY PAPILLOMATOSIS. RECURRENT RESPIRATORY PAPILLOMATOSIS (RRP) IS A RARE AND CHRONIC DISEASE AFFECTING THE UPPER AIRWAY WITH PAPILLOMATOUS LESIONS CAUSED BY THE HUMAN PAPILLOMAVIRUS (HPV) INFECTION, ESPECIALLY HPV-6 AND/OR HPV-11 TYPES. LITTLE IS KNOWN ABOUT THE GENETIC AND EPIGENETIC DRIVERS IN RRP PATHOPHYSIOLOGY. FOR THIS PURPOSE, WE ANALYZED 27 PAPILLOMATOUS LESIONS FROM PATIENTS WITH RRP TO EVALUATE SOMATIC MUTATIONS AND METHYLATION STATUS IN CDKN2A (P14(ARF)/P16(INK4A)) AND TP53, WHICH ARE KEY TUMOR SUPPRESSOR GENES FOR THE CELL CYCLE CONTROL. SANGER SEQUENCING ANALYSIS REVEALED ONE SOMATIC MUTATION IN TP53 (C.733_734INSA) AND FOUR MUTATIONS IN CDKN2A (C.-30G > T, C.29_30INSA, C.69DELT, AND C.300C > A). THESE MUTATIONS WERE OBSERVED IN 10 PATIENTS, 6 OF WHICH CARRIED DOUBLE MUTATION. FURTHERMORE, 50% (5/10) OF THESE PATIENTS CARRYING SOMATIC MUTATIONS HAD RRP SEVERITY, REPRESENTING 62.5% (5/8) OF THE SEVERITY CASES IN THIS STUDY, ALBEIT NO SIGNIFICANT ASSOCIATION WAS FOUND BETWEEN SOMATIC MUTATIONS AND DISEASE SEVERITY. METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION ASSAYS REVEALED P14(ARF) PROMOTER HYPERMETHYLATION IN 100% OF CASES, FOLLOWED BY TP53 (96.3%) AND P16(INK4A) (55.6%), SUGGESTING THE INFLUENCE OF HPV IN THE DNA METHYLATION MACHINERY. IN CONCLUSION, SOMATIC MUTATIONS WERE NOT COMMON EVENTS IDENTIFIED IN PATIENTS WITH RRP. HOWEVER, EPIGENETIC MODULATION BY HIGH METHYLATION RATES, PARTICULARLY FOR THE P14(ARF)/TP53 PATHWAY, SEEMS TO BE IN THE COURSE OF RRP DEVELOPMENT. 2022 3 5004 25 PERIPHERAL B CELLS FROM PATIENTS WITH HEPATITIS C VIRUS-ASSOCIATED LYMPHOMA EXHIBIT CLONAL EXPANSION AND AN ANERGIC-LIKE TRANSCRIPTIONAL PROFILE. CHRONIC HCV INFECTION REMAINS A GLOBAL HEALTH CONCERN DUE TO ITS INVOLVEMENT IN HEPATIC AND EXTRAHEPATIC DISEASES, INCLUDING B CELL NON-HODGKIN LYMPHOMA (BNHL). CLINICAL AND EPIDEMIOLOGICAL EVIDENCE SUPPORT A CAUSAL ROLE FOR HCV IN BNHL DEVELOPMENT, ALTHOUGH MECHANISTIC INSIGHT IS LACKING. WE PERFORMED RNA-SEQUENCING ON PERIPHERAL B CELLS FROM PATIENTS WITH HCV ALONE, BNHL ALONE, AND HCV-ASSOCIATED BNHL TO IDENTIFY UNIQUE AND SHARED TRANSCRIPTIONAL PROFILES ASSOCIATED WITH TRANSFORMATION. IN PATIENTS WITH HCV-ASSOCIATED BNHL, WE OBSERVED THE ENRICHMENT OF AN ANERGIC-LIKE GENE SIGNATURE AND EVIDENCE OF CLONAL EXPANSION THAT WAS CORRELATED WITH THE EXPRESSION OF EPIGENETIC REGULATORY GENES. OUR DATA SUPPORT A ROLE FOR VIRAL-MEDIATED CLONAL EXPANSION OF ANERGIC-LIKE B CELLS IN HCV-ASSOCIATED BNHL DEVELOPMENT AND SUGGEST EPIGENETIC DYSREGULATION AS A POTENTIAL MECHANISM DRIVING EXPANSION. WE PROPOSE EPIGENETIC MECHANISMS MAY BE INVOLVED IN BOTH HCV-ASSOCIATED LYMPHOMA AND REGULATION OF B CELL ANERGY, REPRESENTING AN ATTRACTIVE TARGET FOR CLINICAL INTERVENTIONS. 2023 4 493 27 ASSESSMENT OF P53 AND ATM FUNCTIONALITY IN CHRONIC LYMPHOCYTIC LEUKEMIA BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION. THE ATM-P53 DNA-DAMAGE RESPONSE (DDR) PATHWAY HAS A CRUCIAL ROLE IN CHEMORESISTANCE IN CLL, AS INDICATED BY THE ADVERSE PROGNOSTIC IMPACT OF GENETIC ABERRATIONS OF TP53 AND ATM. IDENTIFYING AND DISTINGUISHING TP53 AND ATM FUNCTIONAL DEFECTS HAS BECOME RELEVANT AS EPIGENETIC AND POSTTRANSCRIPTIONAL DYSREGULATION OF THE ATM/P53 AXIS IS INCREASINGLY BEING RECOGNIZED AS THE UNDERLYING CAUSE OF CHEMORESISTANCE. ALSO, SPECIFIC TREATMENTS SENSITIZING TP53- OR ATM-DEFICIENT CLL CELLS ARE EMERGING. WE THEREFORE DEVELOPED A NEW ATM-P53 FUNCTIONAL ASSAY WITH THE AIM TO (I) IDENTIFY AND (II) DISTINGUISH ABNORMALITIES OF TP53 VERSUS ATM AND (III) ENABLE THE IDENTIFICATION OF ADDITIONAL DEFECTS IN THE ATM-P53 PATHWAY. REVERSED TRANSCRIPTASE MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION (RT-MLPA) WAS USED TO MEASURE ATM AND/OR P53-DEPENDENT GENES AT THE RNA LEVEL FOLLOWING DNA DAMAGE USING IRRADIATION. HERE, WE SHOWED THAT THIS ASSAY IS ABLE TO IDENTIFY AND DISTINGUISH THREE SUBGROUPS OF CLL TUMORS (I.E., TP53-DEFECTIVE, ATM-DEFECTIVE AND WT) AND IS ALSO ABLE TO DETECT ADDITIONAL SAMPLES WITH A DEFECTIVE DDR, WITHOUT MOLECULAR ABERRATIONS IN TP53 AND/OR ATM. THESE FINDINGS MAKE THE ATM-P53 RT-MLPA FUNCTIONAL ASSAY A PROMISING PROGNOSTIC TOOL FOR PREDICTING TREATMENT RESPONSES IN CLL. 2015 5 1067 26 CLINICAL UTILITY OF PDSS2 EXPRESSION TO STRATIFY PATIENTS AT RISK FOR RECURRENCE OF HEPATOCELLULAR CARCINOMA. IDENTIFICATION OF NOVEL GENETIC AND EPIGENETIC ALTERATIONS IS REQUIRED FOR OPTIMAL STRATIFICATION OF PATIENTS WITH HEPATOCELLULAR CARCINOMA (HCC) AT RISK FOR RECURRENCE AND ADVERSE PROGNOSIS. COENZYME Q10 (COQ10), WHICH MEDIATES APOPTOSIS, IS SYNTHESIZED BY PRENYL DIPHOSPHATE SYNTHASE SUBUNIT 2 (PDSS2). IN THE PRESENT STUDY WE EVALUATED THE CLINICAL SIGNIFICANCE AND REGULATORY MECHANISMS OF PDSS2 EXPRESSION IN HCC. PDSS2 EXPRESSION LEVELS AND THOSE OF GENES ENCODING POTENTIALLY INTERACTING PROTEINS AS WELL AS THE METHYLATION STATUS OF THE PDSS2 PROMOTER REGION WERE ANALYZED IN HCC CELL LINES. PDSS2 MRNA LEVELS IN 151 PAIRS OF RESECTED SPECIMENS WERE DETERMINED TO EVALUATE THE ASSOCIATION OF PDSS2 EXPRESSION AND CLINICOPATHOLOGICAL FACTORS. THE EXPRESSION AND DISTRIBUTION OF PDSS2 WERE DETERMINED USING IMMUNOHISTOCHEMISTRY. PDSS2 MRNA EXPRESSION WAS DECREASED IN SIX OF NINE HCC CELL LINES AND SIGNIFICANTLY CORRELATED WITH THOSE OF HEPATOCYTE NUCLEAR FACTOR 4ALPHA. PDSS2 TRANSCRIPTION IN HCC CELLS WITH DECREASED PDSS2 EXPRESSION ACCOMPANYING HYPERMETHYLATION WAS REACTIVATED AFTER TREATING THESE CELLS WITH A METHYLATION INHIBITOR. MEAN EXPRESSION LEVELS OF PDSS2 MRNA RELATIVE TO THAT OF UNINVOLVED LIVER DIMINISHED GRADUALLY IN THE ORDER OF CHRONIC HEPATITIS TO CIRRHOSIS, AND EACH WAS SIGNIFICANTLY HIGHER THAN THOSE OF HCCS. PDSS2 AND PDSS2 MRNA LEVELS WERE CONSISTENT. DECREASED PDSS2 MRNA LEVELS WERE DETECTED IN HCC TISSUES OF 56 PATIENTS, CORRELATED WITH SHORTER DISEASE-SPECIFIC SURVIVAL, AND WAS IDENTIFIED AS AN INDEPENDENT PROGNOSTIC FACTOR. PDSS2 IS A PUTATIVE TUMOR SUPPRESSOR, AND PROMOTER HYPERMETHYLATION IS A KEY REGULATORY MECHANISM IN HCC. DECREASED LEVELS OF PDSS2 MRNA EXPRESSION MAY REPRESENT A NOVEL BIOMARKER OF HCC. 2014 6 2763 31 EXPRESSION OF THE LEUKEMIC PROGNOSTIC MARKER CD7 IS LINKED TO EPIGENETIC MODIFICATIONS IN CHRONIC MYELOID LEUKEMIA. BACKGROUND: EXPRESSION LEVELS OF THE CELL SURFACE GLYCOPROTEIN, CD7, AND THE SERINE PROTEASE, ELASTASE 2 (ELA2), IN THE LEUKEMIC CELLS OF PATIENTS WITH CHRONIC MYELOID LEUKEMIA (CML) HAVE BEEN ASSOCIATED WITH CLINICAL OUTCOME. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS THAT UNDERLIE THE VARIABLE EXPRESSION OF THESE GENES IN THE LEUKEMIC CELLS. RESULTS: TO ADDRESS THIS QUESTION, WE COMPARED THE LEVEL OF THEIR EXPRESSION WITH THE DNA METHYLATION AND HISTONE ACETYLATION STATUS OF 5' SEQUENCES OF BOTH GENES IN LEUKEMIC CELL LINES AND PRIMITIVE (LIN-CD34+) LEUKEMIC CELLS FROM CHRONIC PHASE CML PATIENTS. DNA METHYLATION OF THE ELA2 GENE PROMOTER DID NOT CORRELATE WITH ITS EXPRESSION PATTERN IN LIN-CD34+ CELLS FROM CHRONIC PHASE CML PATIENT SAMPLES EVEN THOUGH THERE WAS CLEAR DIFFERENTIAL DNA METHYLATION OF THIS LOCUS IN ELA2-EXPRESSING AND NON-EXPRESSING CELL LINES. IN CONTRAST, WE FOUND A STRONG RELATION BETWEEN CD7 EXPRESSION AND TRANSCRIPTION-PERMISSIVE CHROMATIN MODIFICATIONS, BOTH AT THE LEVEL OF DNA METHYLATION AND HISTONE ACETYLATION WITH EVIDENCE OF HYPOMETHYLATION OF THE CD7 PROMOTER REGION IN THE LIN-CD34+ CELLS FROM CML PATIENTS WITH HIGH CD7 EXPRESSION. CONCLUSION: THESE FINDINGS INDICATE A LINK BETWEEN EPIGENETIC MODIFICATIONS AND CD7 EXPRESSION IN PRIMITIVE CML CELLS. 2010 7 4225 22 METHYLATION DEGREE OF METALLOPROTEINASE INHIBITOR RECK GENE: LINKS TO RECK PROTEIN LEVEL AND HEPATOCELLULAR CARCINOMA IN CHRONIC HCV INFECTION PATIENTS. THE RECK GENE, A TUMOR SUPPRESSOR GENE, INHIBITS ANGIOGENESIS, INVASION, AND TUMOR METASTASIS. EPIGENETIC REGULATION OF THE RECK GENE CONSTITUTES A POTENT APPROACH TO THE MOLECULAR BASIS OF LIVER MALIGNANCY. THIS STUDY AIMS TO EVALUATE THE PROMOTER METHYLATION STATUS OF THE RECK GENE AND ITS SERUM LEVEL IN PATIENTS WITH HEPATITIS C VIRUS (HCV)-RELATED HEPATOCELLULAR CARCINOMA (HCC) AND THE POTENTIAL ASSOCIATION OF RECK GENE METHYLATION WITH CLINICAL CRITERIA OF HCC. ONE HUNDRED AND FIFTY-FIVE SUBJECTS WERE INCLUDED (HEALTHY CONTROL [55], CHRONIC HCV PATIENTS [55], HCV-RELATED HCC PATIENTS [45]). THE METHYLATION STATUS OF THE RECK GENE PROMOTER AND SERUM RECK LEVEL WERE INVESTIGATED BY METHYLATION-SPECIFIC PCR AND ENZYME-LINKED IMMUNOSORBENT ASSAY TECHNIQUES, RESPECTIVELY. RECK GENE PROMOTER HYPERMETHYLATION WAS RECORDED IN 46.7% OF HCC PATIENTS, AND 10.9% OF HCV PATIENTS, BUT NOT IN CONTROL SUBJECTS (0%). IT WAS RELATED TO RECK PROTEIN LEVEL, VARICES, EDEMA, ASCITES, LYMPH NODE METASTASIS, VASCULAR INVASION, AND THE LARGEST DIAMETER OF FOCAL LESIONS. MEANWHILE, IT WAS NOT ASSOCIATED WITH FOCAL LESION NUMBER NOR DISTANT METASTASIS OF HCC. IN CONCLUSION, RECK GENE PROMOTER HYPERMETHYLATION IS LINKED TO HCV GENOTYPE-4-RELATED HCC. MOREOVER, DIFFERENT DEGREES OF RECK GENE PROMOTER METHYLATION ARE ASSOCIATED WITH SERUM RECK LEVEL, LYMPH NODE METASTASIS, AND VASCULAR INVASION, WHICH COULD PROVE ITS PATHOGENIC ROLE IN HEPATOCARCINOGENESIS IN CHRONIC HCV-INFECTED PATIENTS. 2021 8 3198 24 HDAC-LINKED "PROLIFERATIVE" MIRNA EXPRESSION PATTERN IN PANCREATIC NEUROENDOCRINE TUMORS. EPIGENETIC FACTORS ARE ESSENTIALLY INVOLVED IN CARCINOGENESIS, TUMOR PROMOTION, AND CHEMORESISTANCE. TWO EPIGENETIC KEY PLAYERS ARE MIRNAS AND HISTONE DEACETYLASES (HDACS). AS PREVIOUSLY SHOWN BY OWN THEORETICAL DATABANK ANALYSIS, THE CROSSTALK BETWEEN MIRNAS AND HDACS IS RELEVANT IN DIFFERENT HUMAN CHRONIC DISEASES AND CANCEROGENIC PATHWAYS. WE AIMED TO INVESTIGATE A POTENTIAL CONNECTION BETWEEN THE EXPRESSION OF A WELL-DEFINED SUBSET OF "PROLIFERATION-ASSOCIATED" MIRNAS AND THE EXPRESSION OF HDACS AS WELL AS CLINICAL PARAMETERS IN PANCREATIC NEUROENDOCRINE TUMORS (PNETS). MATERIALS AND METHODS: EXPRESSION LEVELS OF MIRNA132-3P, MIRNA145-5P, MIRNA183-5P, MIRNA34A-5P, AND MIRNA449A IN 57 PNETS RESECTED BETWEEN 1997 AND 2015 WERE MEASURED AND LINKED TO THE IMMUNOHISTOCHEMICAL EXPRESSION PATTERN OF MEMBERS OF THE FOUR HDAC CLASSES ON HUMAN TISSUE MICROARRAYS. ALL PNET CASES WERE CLINICALLY AND PATHOLOGICALLY CHARACTERIZED ACCORDING TO PUBLISHED GUIDELINES. CORRELATION ANALYSIS REVEALED A SIGNIFICANT ASSOCIATION BETWEEN EXPRESSION OF SPECIFIC MIRNAS AND TWO MEMBERS OF THE HDAC FAMILY (HDAC3 AND HDAC4). ADDITIONALLY, A LINKAGE BETWEEN MIRNA EXPRESSION AND CLINICO-PATHOLOGICAL PARAMETERS LIKE GRADING, TNM-STAGING, AND HORMONE ACTIVITY WAS FOUND. MOREOVER, OVERALL AND DISEASE-FREE SURVIVAL IS STATISTICALLY CORRELATED WITH THE EXPRESSION OF THE INVESTIGATED MIRNAS. OVERALL, WE DEMONSTRATED THAT SPECIFIC MIRNAS COULD BE LINKED TO HDAC EXPRESSION IN PNETS. ESPECIALLY MIRNA449A (ASSOCIATED WITH HDAC3/4) SEEMS TO PLAY AN IMPORTANT ROLE IN PNET PROLIFERATION AND COULD BE A POTENTIAL PROGNOSTIC FACTOR FOR POOR SURVIVAL. THESE FIRST DATA COULD HELP, TO IMPROVE OUR KNOWLEDGE OF THE COMPLEX INTERACTIONS OF THE EPIGENETIC DRIVERS IN PNETS FOR FURTHER THERAPEUTIC APPROACHES. 2018 9 3049 26 GENOME-WIDE ANALYSIS REVEALS ZINC TRANSPORTER ZIP9 REGULATED BY DNA METHYLATION PROMOTES RADIATION-INDUCED SKIN FIBROSIS VIA THE TGF-BETA SIGNALING PATHWAY. RADIATION-INDUCED SKIN FIBROSIS IS A DETRIMENTAL AND CHRONIC DISORDER THAT OCCURS AFTER RADIATION EXPOSURE. DNA METHYLATION HAS BEEN CHARACTERIZED AS AN IMPORTANT REGULATORY MECHANISM OF MULTIPLE PATHOLOGICAL PROCESSES. IN THIS STUDY, WE COMPARED THE GENOME-WIDE DNA METHYLATION STATUS IN RADIATION-INDUCED FIBROTIC SKIN AND ADJACENT NORMAL TISSUES OF RATS BY METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING. RADIATION-INDUCED FIBROTIC SKIN SHOWED DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH 3,650 PROTEIN-CODING GENES, 72 MICRORNAS, 5,836 LONG NONCODING RNAS AND 3 PIWI-INTERACTING RNAS. BY INTEGRATING THE MRNA AND METHYLATION PROFILES, THE ZINC TRANSPORTER SLC39A9/ZIP9 WAS INVESTIGATED IN GREATER DETAIL. THE PROTEIN LEVEL OF ZIP9 WAS INCREASED IN IRRADIATED SKIN TISSUES OF HUMANS, MONKEYS, AND RATS, ESPECIALLY IN RADIOGENIC FIBROTIC SKIN TISSUES. RADIATION INDUCED THE DEMETHYLATION OF A CPG DINUCLEOTIDE IN EXON 1 OF ZIP9 THAT RESULTED IN RECRUITMENT OF THE TRANSCRIPTIONAL FACTOR SP1 AND INCREASED ZIP9 EXPRESSION. OVEREXPRESSION OF ZIP9 RESULTED IN ACTIVATION OF THE PROFIBROTIC TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY THROUGH PROTEIN KINASE B IN HUMAN FIBROBLASTS. IN ADDITION, RADIATION-INDUCED SKIN FIBROSIS WAS ASSOCIATED WITH INCREASED ZINC ACCUMULATION. THE ZINC CHELATOR N,N,N',N'-TETRAKIS(2-PYRIDYLMETHYL)-1,2-ETHYLENEDIAMINE ABROGATED ZIP9-INDUCED ACTIVATION OF THE TRANSFORMING GROWTH FACTOR-BETA SIGNALING PATHWAY AND ATTENUATED RADIATION-INDUCED SKIN FIBROSIS IN A RAT MODEL. IN SUMMARY, OUR FINDINGS ILLUSTRATE EPIGENETIC REGULATION OF ZIP9 AND ITS CRITICAL ROLE IN PROMOTING RADIATION-INDUCED SKIN FIBROSIS. 2020 10 5433 16 REL/NF-KAPPA B/I KAPPA B SIGNAL TRANSDUCTION IN THE GENERATION AND TREATMENT OF HUMAN CANCER. THE REL/NF-KAPPA B FAMILY IS A GROUP OF STRUCTURALLY-RELATED, TIGHTLY-REGULATED TRANSCRIPTION FACTORS THAT CONTROL THE EXPRESSION OF A MULTITUDE OF GENES INVOLVED IN KEY CELLULAR AND ORGANISMAL PROCESSES. THE REL/NF-KAPPA B SIGNAL TRANSDUCTION PATHWAY IS MISREGULATED IN A VARIETY OF HUMAN CANCERS, ESPECIALLY ONES OF LYMPHOID CELL ORIGIN, DUE EITHER TO GENETIC CHANGES (SUCH AS CHROMOSOMAL REARRANGEMENTS, AMPLIFICATIONS, AND MUTATIONS) OR TO CHRONIC ACTIVATION OF THE PATHWAY BY EPIGENETIC MECHANISMS. CONSTITUTIVE ACTIVATION OF THE REL/NF-KAPPA B PATHWAY CAN CONTRIBUTE TO THE ONCOGENIC STATE IN SEVERAL WAYS, FOR EXAMPLE, BY DRIVING PROLIFERATION, BY ENHANCING CELL SURVIVAL, OR BY PROMOTING ANGIOGENESIS OR METASTASIS. IN MANY CASES, INHIBITION OF REL/NF-KAPPA B ACTIVITY REVERSES ALL OR PART OF THE MALIGNANT STATE. THUS, THE REL/NF-KAPPA B PATHWAY HAS RECEIVED MUCH ATTENTION AS A FOCAL POINT FOR CLINICAL INTERVENTION. 2002 11 499 31 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 12 136 25 ABERRANT DNA HYPERMETHYLATION PATTERNS LEAD TO TRANSCRIPTIONAL SILENCING OF TUMOR SUPPRESSOR GENES IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS OF MICE. OVEREXPOSURE OF THE HUMAN SKIN TO SOLAR ULTRAVIOLET (UV) RADIATION IS THE MAJOR ETIOLOGIC FACTOR FOR DEVELOPMENT OF SKIN CANCERS. HERE, WE REPORT THE RESULTS OF EPIGENETIC MODIFICATIONS IN UV-EXPOSED SKIN AND SKIN TUMORS IN A SYSTEMATIC MANNER. THE SKIN AND TUMOR SAMPLES WERE COLLECTED AFTER CHRONIC EXPOSURE OF THE SKIN OF SKH-1 HAIRLESS MICE TO UVB RADIATION USING A WELL-ESTABLISHED PHOTOCARCINOGENESIS PROTOCOL. WE FOUND A DISTINCT DNA HYPERMETHYLATION PATTERN IN THE UVB-EXPOSED EPIDERMAL SKIN AND UVB-INDUCED SKIN TUMORS THAT WAS ASSOCIATED WITH THE ELEVATED EXPRESSION AND ACTIVITY OF THE DNA METHYLTRANSFERASES (DNMT) 1, DNMT3A AND DNMT3B. TO EXPLORE THE ROLE OF HYPERMETHYLATION IN SKIN PHOTOCARCINOGENESIS, WE FOCUSED ON THE P16(INK4A) AND RASSF1A TUMOR SUPPRESSOR GENES, WHICH ARE TRANSCRIPTIONALLY SILENCED ON METHYLATION. WE ESTABLISHED THAT THE SILENCING OF THESE GENES IN UVB-EXPOSED EPIDERMIS AND UVB-INDUCED SKIN TUMORS IS ASSOCIATED WITH A NETWORK OF EPIGENETIC MODIFICATIONS, INCLUDING HYPOACETYLATION OF HISTONE H3 AND H4 AND INCREASED HISTONE DEACETYLATION, AS WELL AS RECRUITMENT OF METHYL-BINDING PROTEINS, INCLUDING MECP2 AND MBD1, TO THE METHYLATED CPGS. HIGHER LEVELS OF DNA METHYLATION AND DNMT ACTIVITY IN HUMAN SQUAMOUS CELL CARCINOMA SPECIMENS THAN IN NORMAL HUMAN SKIN SUGGEST THAT THE DATA ARE RELEVANT CLINICALLY. OUR DATA INDICATE FOR THE FIRST TIME THAT UVB-INDUCED DNA HYPERMETHYLATION, ENHANCED DNMT ACTIVITY AND HISTONE MODIFICATIONS OCCUR IN UVB-EXPOSED SKIN AND UVB-INDUCED SKIN TUMORS AND SUGGEST THAT THESE EVENTS ARE INVOLVED IN THE SILENCING OF TUMOR SUPPRESSOR GENES AND IN SKIN TUMOR DEVELOPMENT. 2011 13 3327 26 HISTONE DEACETYLASE 4 PROMOTES CHOLESTATIC LIVER INJURY IN THE ABSENCE OF PROHIBITIN-1. PROHIBITIN-1 (PHB1) IS AN EVOLUTIONARILY CONSERVED PLEIOTROPIC PROTEIN THAT PARTICIPATES IN DIVERSE PROCESSES DEPENDING ON ITS SUBCELLULAR LOCALIZATION AND INTERACTOME. RECENT DATA HAVE INDICATED A DIVERSE ROLE FOR PHB1 IN THE PATHOGENESIS OF OBESITY, CANCER, AND INFLAMMATORY BOWEL DISEASE, AMONG OTHERS. DATA PRESENTED HERE SUGGEST THAT PHB1 IS ALSO LINKED TO CHOLESTATIC LIVER DISEASE. EXPRESSION OF PHB1 IS MARKEDLY REDUCED IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS AND BILIARY ATRESIA OR WITH ALAGILLE SYNDROME, TWO MAJOR PEDIATRIC CHOLESTATIC CONDITIONS. IN THE EXPERIMENTAL MODEL OF BILE DUCT LIGATION, SILENCING OF PHB1 INDUCED LIVER FIBROSIS, REDUCED ANIMAL SURVIVAL, AND INDUCED BILE DUCT PROLIFERATION. IMPORTANTLY, THE MODULATORY EFFECT OF PHB1 IS NOT DEPENDENT ON ITS KNOWN MITOCHONDRIAL FUNCTION. ALSO, PHB1 INTERACTS WITH HISTONE DEACETYLASE 4 (HDAC4) IN THE PRESENCE OF BILE ACIDS. HENCE, PHB1 DEPLETION LEADS TO INCREASED NUCLEAR HDAC4 CONTENT AND ITS ASSOCIATED EPIGENETIC CHANGES. REMARKABLY, HDAC4 SILENCING AND THE ADMINISTRATION OF THE HDAC INHIBITOR PARTHENOLIDE DURING OBSTRUCTIVE CHOLESTASIS IN VIVO PROMOTE GENOMIC REPROGRAMMING, LEADING TO REGRESSION OF THE FIBROTIC PHENOTYPE IN LIVER-SPECIFIC PHB1 KNOCKOUT MICE. CONCLUSION: PHB1 IS AN IMPORTANT MEDIATOR OF CHOLESTATIC LIVER INJURY THAT REGULATES THE ACTIVITY OF HDAC4, WHICH CONTROLS SPECIFIC EPIGENETIC MARKERS; THESE RESULTS IDENTIFY POTENTIAL NOVEL STRATEGIES TO TREAT LIVER INJURY AND FIBROSIS, PARTICULARLY AS A CONSEQUENCE OF CHRONIC CHOLESTASIS. 2015 14 2948 30 GENETIC AND EPIGENETIC CHARACTERISTICS OF INFLAMMATORY BOWEL DISEASE-ASSOCIATED COLORECTAL CANCER. BACKGROUND & AIMS: INFLAMMATORY BOWEL DISEASE (IBD) IS A CHRONIC, RELAPSING INFLAMMATORY DISORDER ASSOCIATED WITH AN ELEVATED RISK OF COLORECTAL CANCER (CRC). IBD-ASSOCIATED CRC (IBD-CRC) MAY REPRESENT A DISTINCT PATHWAY OF TUMORIGENESIS COMPARED TO SPORADIC CRC (SCRC). OUR AIM WAS TO COMPREHENSIVELY CHARACTERIZE IBD-ASSOCIATED TUMORIGENESIS INTEGRATING MULTIPLE HIGH-THROUGHPUT APPROACHES, AND TO COMPARE THE RESULTS WITH IN-HOUSE DATA SETS FROM SCRCS. METHODS: WHOLE-GENOME SEQUENCING, SINGLE NUCLEOTIDE POLYMORPHISM ARRAYS, RNA SEQUENCING, GENOME-WIDE METHYLATION ANALYSIS, AND IMMUNOHISTOCHEMISTRY WERE PERFORMED USING FRESH-FROZEN AND FORMALIN-FIXED TISSUE SAMPLES OF TUMOR AND CORRESPONDING NORMAL TISSUES FROM 31 PATIENTS WITH IBD-CRC. RESULTS: TRANSCRIPTOME-BASED TUMOR SUBTYPING REVEALED THE COMPLETE ABSENCE OF CANONICAL EPITHELIAL TUMOR SUBTYPE ASSOCIATED WITH WNT SIGNALING IN IBD-CRCS, DOMINATED INSTEAD BY MESENCHYMAL STROMA-RICH SUBTYPE. NEGATIVE WNT REGULATORS AXIN2 AND RNF43 WERE STRONGLY DOWN-REGULATED IN IBD-CRCS AND CHROMOSOMAL GAINS AT HNF4A, A NEGATIVE REGULATOR OF WNT-INDUCED EPITHELIAL-MESENCHYMAL TRANSITION (EMT), WERE LESS FREQUENT COMPARED TO SCRCS. ENRICHMENT OF HYPOMETHYLATION AT HNF4ALPHA BINDING SITES WAS DETECTED SOLELY IN SCRC GENOMES. PIGR AND OSMR INVOLVED IN MUCOSAL IMMUNITY WERE DYSREGULATED VIA EPIGENETIC MODIFICATIONS IN IBD-CRCS. GENOME-WIDE ANALYSIS SHOWED SIGNIFICANT ENRICHMENT OF NONCODING MUTATIONS TO 5'UNTRANSLATED REGION OF TP53 IN IBD-CRCS. AS REPORTED PREVIOUSLY, SOMATIC MUTATIONS IN APC AND KRAS WERE LESS FREQUENT IN IBD-CRCS COMPARED TO SCRCS. CONCLUSIONS: DISTINCT MECHANISMS OF WNT PATHWAY DYSREGULATION SKEW IBD-CRCS TOWARD MESENCHYMAL TUMOR SUBTYPE, WHICH MAY AFFECT PROGNOSIS AND TREATMENT OPTIONS. INCREASED OSMR SIGNALING MAY FAVOR THE ESTABLISHMENT OF MESENCHYMAL TUMORS IN PATIENTS WITH IBD. 2021 15 546 31 ATTENUATED EXPRESSION OF SLCO2A1 CAUSED BY DNA METHYLATION IN PEDIATRIC INFLAMMATORY BOWEL DISEASE. BACKGROUND: SLCO2A1 ENCODES A PROSTAGLANDIN (PG) TRANSPORTER, AND AUTOSOMAL RECESSIVE PATHOGENIC VARIANTS OF THIS GENE CAUSE CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1. IT IS UNCLEAR WHETHER A HETEROZYGOUS PATHOGENIC VARIANT OF SLCO2A1 HAS A ROLE IN THE PATHOGENESIS OF OTHER TYPES OF INFLAMMATORY BOWEL DISEASE (IBD). IN THIS STUDY, WE INVESTIGATED THE POSSIBLE INVOLVEMENT OF A LOCAL EPIGENETIC ALTERATION IN SLCO2A1 IN PATIENTS WITH A HETEROZYGOUS PATHOGENIC VARIANT. METHODS: WE CONDUCTED WHOLE-EXOME SEQUENCING OF SAMPLES FROM 2 SISTERS WITH SUSPECTED MONOGENIC IBD. IN ADDITION, WE PERFORMED BISULFITE SEQUENCING USING DNA EXTRACTED FROM THEIR SMALL AND LARGE INTESTINE SAMPLES TO EXPLORE EPIGENETIC ALTERATIONS. RESULTS: A HETEROZYGOUS SPLICING SITE VARIANT, SLCO2A1:C.940 + 1G > A, WAS DETECTED IN BOTH PATIENTS. TO EXPLORE THE POSSIBLE INVOLVEMENT OF EPIGENETIC ALTERATIONS, WE ANALYZED PROTEIN AND MESSENGER RNA EXPRESSION OF SLCO2A1, AND OBSERVED ATTENUATED SLCO2A1 EXPRESSION IN THE INFLAMED LESIONS OF THESE PATIENTS COMPARED WITH THAT IN THE CONTROL INDIVIDUALS. FURTHERMORE, BISULFITE SEQUENCING INDICATED DENSE METHYLATION IN THE PROMOTER REGION OF SLCO2A1 ONLY IN THE INFLAMED LESIONS OF BOTH PATIENTS. THE URINARY PG METABOLITE LEVELS IN THESE PATIENTS WERE COMPARABLE TO THOSE IN PATIENTS WITH CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1 AND HIGHER THAN THOSE IN THE CONTROL INDIVIDUALS. WE FOUND CONSIDERABLY HIGHER LEVELS OF THE METABOLITES IN PATIENT 1, WHO SHOWED MORE SEVERE SYMPTOMS THAN PATIENT 2. CONCLUSIONS: LOCAL DNA METHYLATION ATTENUATED SLCO2A1 EXPRESSION, WHICH MAY EVOKE LOCAL INFLAMMATION OF THE MUCOSA BY THE UNINCORPORATED PG. THESE FINDINGS MAY IMPROVE OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS UNDERLYING IBD DEVELOPMENT. 2023 16 1861 15 EMERGENCE OF CANCER STEM CELLS IN HEPATOCELLULAR CARCINOMA. LIVER CANCER REPRESENTS THE SECOND MOST DEADLY HUMAN MALIGNANCY. THE MAJOR HISTOLOGICAL SUBTYPE CALLED HEPATOCELLULAR CARCINOMA (HCC) ARISES BY CHRONIC INFLAMMATION-TRIGGERED REGENERATIVE RESPONSES OF NORMALLY QUIESCENT HEPATOCYTES AND PROGENITORS, RESPECTIVELY. SUCH REGENERATIVE STRESS ACCELERATES THE ACCUMULATION OF GENETIC AND EPIGENETIC CHANGES (YAMASHITA & WANG, 2013), WHILE DETAILED MECHANISMS REMAIN UNCERTAIN. IN THIS ISSUE OF THE EMBO JOURNAL, NIKOLAOU ET AL PRESENT A NOVEL HCC MODEL THAT FACILITATES BOTH ISOLATION AND MOLECULAR CHARACTERIZATION OF SELF-RENEWING, HCC-PROPAGATING CANCER STEM CELLS THAT COULD INSTRUCT FUTURE INTERVENTIONS (NIKOLAOU ET AL, 2014). 2015 17 1121 20 COMPARISON OF EPIGENETIC PROFILES OF HUMAN ORAL EPITHELIAL CELLS FROM HIV-POSITIVE (ON HAART) AND HIV-NEGATIVE SUBJECTS. HIV-INFECTED SUBJECTS ON HIGHLY ACTIVE ANTIRETROVIRAL THERAPY (HAART) ARE SUSCEPTIBLE TO COMORBID MICROBIAL INFECTIONS IN THE ORAL CAVITY. WE OBSERVED THAT PRIMARY ORAL EPITHELIAL CELLS (POECS) ISOLATED FROM HIV+ SUBJECTS ON HAART GROW MORE SLOWLY AND ARE LESS INNATE IMMUNE RESPONSIVE TO MICROBIAL CHALLENGE WHEN COMPARED WITH POECS FROM NORMAL SUBJECTS. THESE ABERRANT CELLS ALSO DEMONSTRATE EPIGENETIC DIFFERENCES THAT INCLUDE REDUCTION IN HISTONE DEACETYLASE 1 (HDAC-1) LEVELS AND REDUCED TOTAL DNA METHYLTRANSFERASE (DNMT) ACTIVITY SPECIFIC TO ENZYMES DNMT1 AND DNMT3A. THE DNMT ACTIVITY CORRELATES WELL WITH GLOBAL DNA METHYLATION, INDICATING THAT ABERRANT DNMT ACTIVITY IN HIV+ (ON HAART) POECS LEADS TO AN ABERRANTLY METHYLATED EPITHELIAL CELL PHENOTYPE. OVERALL, OUR RESULTS LEAD US TO HYPOTHESIZE THAT, IN PATIENTS WITH CHRONIC HIV INFECTION ON HAART, EPIGENETIC CHANGES IN KEY GENES RESULT IN INCREASED VULNERABILITY TO MICROBIAL INFECTION IN THE ORAL CAVITY. 2013 18 1334 25 DEREGULATION OF AIOLOS EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS CHARACTERIZED BY A CLONAL ACCUMULATION OF MATURE NEOPLASTIC B CELLS THAT ARE RESISTANT TO APOPTOSIS. AIOLOS, A MEMBER OF THE IKAROS FAMILY OF ZINC-FINGER TRANSCRIPTION FACTORS, PLAYS AN IMPORTANT ROLE IN THE CONTROL OF MATURE B LYMPHOCYTE DIFFERENTIATION AND MATURATION. IN THIS STUDY, WE SHOWED THAT AIOLOS EXPRESSION IS UP-REGULATED IN B-CLL CELLS. THIS OVEREXPRESSION DOES NOT IMPLICATE ISOFORM IMBALANCE OR DISTURB AIOLOS SUBCELLULAR LOCALIZATION. THE CHROMATIN STATUS AT THE AIOLOS PROMOTER IN CLL IS DEFINED BY THE DEMETHYLATION OF DNA AND AN ENRICHMENT OF EUCHROMATIN ASSOCIATED HISTONE MARKERS, SUCH AS THE DIMETHYLATION OF THE LYSINE 4 ON HISTONE H3. THESE EPIGENETIC MODIFICATIONS SHOULD ALLOW ITS UPSTREAM EFFECTORS, SUCH AS NUCLEAR FACTOR-KAPPAB, CONSTITUTIVELY ACTIVATED IN CLL, TO GAIN ACCESS TO PROMOTER, RESULTING UP-REGULATION OF AIOLOS. TO DETERMINE THE CONSEQUENCES OF AIOLOS DEREGULATION IN CLL, WE ANALYZED THE EFFECTS OF AIOLOS OVEREXPRESSION OR DOWN-REGULATION ON APOPTOSIS. AIOLOS IS INVOLVED IN CELL SURVIVAL BY REGULATING THE EXPRESSION OF SOME BCL-2 FAMILY MEMBERS. OUR RESULTS STRONGLY SUGGEST THAT AIOLOS DEREGULATION BY EPIGENETIC MODIFICATIONS MAY BE A HALLMARK OF CLL. 2011 19 2761 21 EXPRESSION OF TESTIS-SPECIFIC GENES, TEX101 AND ODF4, IN CHRONIC MYELOID LEUKEMIA AND EVALUATION OF TEX101 IMMUNOGENICITY. BACKGROUND AND OBJECTIVES: CANCER-TESTIS (CT) ANTIGENS ARE A GROUP OF ANTIGENS WITH A RESTRICTED EXPRESSION IN NORMAL TISSUES, EXCEPT TESTIS, AND THEY HAVE ABERRANT EXPRESSION IN DIFFERENT TUMORS. THIS PATTERN OF EXPRESSION HAS MADE THEM PROMISING TARGETS FOR IMMUNOTHERAPY AND CANCER DETECTION. OUR AIM WAS TO FIND NEW MEMBERS OF THIS GROUP THAT MIGHT BE USEFUL AS MARKERS IN THE DETECTION OF CANCER AND IMMUNOTHERAPY. DESIGN AND SETTING: A DESCRIPTIVE STUDY CONDUCTED IN REFERRAL CENTERS OF TEHRAN UNIVERSITY OF MEDICAL SCIENCE FROM JANUARY 2008 TO JANUARY 2009. PATIENTS AND METHODS: WE ANALYZED THE EXPRESSION OF TWO TESTIS-SPECIFIC GENES NAMED ODF4 (OUTER DENSE FIBER OF SPERM TAILS 4) AND TEX101 (TESTIS EXPRESSED 101) IN 20 CHRONIC MYELOID LEUKEMIA (CML) AND 20 NORMAL SAMPLES BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION AND SEQUENCING. IMMUNOGENICITY OF TEX101 WAS EVALUATED BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY. RESULTS: THESE TWO GENES WERE EXPRESSED IN 30% OF CML PATIENTS BUT NOT IN ANY OF THE HEALTHY DONORS. HUMORAL RESPONSE AGAINST TEX101 WAS NOT DETECTED IN ANY SAMPLES. CONCLUSIONS: TEX101 AND ODF4 ARE CT GENES USEFUL FOR DETECTION OF CML. UNLIKE MANY CT GENES, OVEREXPRESSION OF TEX101 WAS NOT SHOWN TO INDUCE IMMUNOLOGIC RESPONSES IN THESE SAMPLES. ACCORDING TO THE PREVIOUS STUDIES, OVEREXPRESSION OF TEX101 LEADS TO SUPPRESSION OF CANCER INVASION AND METASTASIS; THUS, THE INDUCTION OF THE EXPRESSION OF TEX101 IN CANCER BY EPIGENETIC MECHANISMS MAY BE A TREATMENT STRATEGY. 2012 20 62 23 A HIGH DEFINITION PICTURE OF SOMATIC MUTATIONS IN CHRONIC LYMPHOPROLIFERATIVE DISORDER OF NATURAL KILLER CELLS. THE MOLECULAR PATHOGENESIS OF CHRONIC LYMPHOPROLIFERATIVE DISORDER OF NATURAL KILLER (NK) CELLS (CLPD-NK) IS POORLY UNDERSTOOD. FOLLOWING THE SCREENING OF 57 CLPD-NK PATIENTS, ONLY FIVE PRESENTED STAT3 MUTATIONS. WES PROFILING OF 13 CASES NEGATIVE FOR STAT3/STAT5B MUTATIONS UNCOVERED AN AVERAGE OF 18 CLONAL, POPULATION RARE AND DELETERIOUS SOMATIC VARIANTS PER PATIENT. THE MUTATIONAL LANDSCAPE OF CLPD-NK SHOWED THAT MOST PATIENTS CARRY A HEAVY MUTATIONAL BURDEN, WITH MAJOR AND SUBCLONAL DELETERIOUS MUTATIONS CO-EXISTING IN THE LEUKEMIC CLONE. SOMATIC MUTATIONS HIT GENES WIRED TO CANCER PROLIFERATION, SURVIVAL, AND MIGRATION PATHWAYS, IN THE FIRST PLACE RAS/MAPK, PI3K-AKT, IN ADDITION TO JAK/STAT (PIK3R1 AND PTK2). WE CONFIRMED VARIANTS WITH PUTATIVE DRIVER ROLE OF MAP10, MPZL1, RPS6KA1, SETD1B, TAOK2, TMEM127, AND TNFRSF1A GENES, AND OF GENES LINKED TO VIRAL INFECTIONS (DDX3X AND RSF1) AND DNA REPAIR (PAXIP1). A TRUNCATING MUTATION OF THE EPIGENETIC REGULATOR TET2 AND A VARIANT LIKELY ABROGATING PIK3R1-NEGATIVE REGULATORY ACTIVITY WERE VALIDATED. THIS STUDY SIGNIFICANTLY FURTHERED THE VIEW OF THE GENES AND PATHWAYS INVOLVED IN CLPD-NK, INDICATED SIMILARITIES WITH AGGRESSIVE DISEASES OF NK CELLS AND DETECTED MUTATED GENES TARGETABLE BY APPROVED DRUGS, BEING A STEP FORWARD TO PERSONALIZED PRECISION MEDICINE FOR CLPD-NK PATIENTS. 2020