1 62 132 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 2 493 26 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 3 4556 24 MUTATIONAL SPECTRUM OF MYELOID MALIGNANCIES WITH INV(3)/T(3;3) REVEALS A PREDOMINANT INVOLVEMENT OF RAS/RTK SIGNALING PATHWAYS. MYELOID MALIGNANCIES BEARING CHROMOSOMAL INV(3)/T(3;3) ABNORMALITIES ARE AMONG THE MOST THERAPY-RESISTANT LEUKEMIAS. DEREGULATED EXPRESSION OF EVI1 IS THE MOLECULAR HALLMARK OF THIS DISEASE; HOWEVER, THE GENOME-WIDE SPECTRUM OF COOPERATING MUTATIONS IN THIS DISEASE SUBSET HAS NOT BEEN SYSTEMATICALLY ELUCIDATED. HERE, WE SHOW THAT 98% OF INV(3)/T(3;3) MYELOID MALIGNANCIES HARBOR MUTATIONS IN GENES ACTIVATING RAS/RECEPTOR TYROSINE KINASE (RTK) SIGNALING PATHWAYS. IN ADDITION, HEMIZYGOUS MUTATIONS IN GATA2, AS WELL AS HETEROZYGOUS ALTERATIONS IN RUNX1, SF3B1, AND GENES ENCODING EPIGENETIC MODIFIERS, FREQUENTLY CO-OCCUR WITH THE INV(3)/T(3;3) ABERRATION. NOTABLY, NEITHER MUTATIONAL PATTERNS NOR GENE EXPRESSION PROFILES DIFFER ACROSS INV(3)/T(3;3) ACUTE MYELOID LEUKEMIA, CHRONIC MYELOID LEUKEMIA, AND MYELODYSPLASTIC SYNDROME CASES, SUGGESTING RECOGNITION OF INV(3)/T(3;3) MYELOID MALIGNANCIES AS A SINGLE DISEASE ENTITY IRRESPECTIVE OF BLAST COUNT. THE HIGH INCIDENCE OF ACTIVATING RAS/RTK SIGNALING MUTATIONS MAY PROVIDE A TARGET FOR A RATIONAL TREATMENT STRATEGY IN THIS HIGH-RISK PATIENT GROUP. 2015 4 2763 21 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 5 5608 25 RUNX1-EVI1 DISRUPTS LINEAGE DETERMINATION AND THE CELL CYCLE BY INTERFERING WITH RUNX1 AND EVI1 DRIVEN GENE REGULATORY NETWORKS. HEMATOLOGICAL MALIGNANCIES ARE CHARACTERISED BY A BLOCK IN DIFFERENTIATION, WHICH IN MANY CASES IS CAUSED BY RECURRENT MUTATIONS AFFECTING THE ACTIVITY OF HEMATOPOIETIC TRANSCRIPTION FACTORS. RUNX1-EVI1 IS A FUSION PROTEIN FORMED BY THE T(3;21) TRANSLOCATION LINKING TWO TRANSCRIPTION FACTORS REQUIRED FOR NORMAL HEMATOPOIESIS. RUNX1-EVI1 EXPRESSION IS FOUND IN MYELODYSPLASTIC SYNDROME, SECONDARY ACUTE MYELOID LEUKEMIA, AND BLAST CRISIS OF CHRONIC MYELOID LEUKEMIA; WITH CLINICAL OUTCOMES BEING WORSE THAN IN PATIENTS WITH RUNX1-ETO, RUNX1 OR EVI1 MUTATIONS ALONE. RUNX1-EVI1 IS USUALLY FOUND AS A SECONDARY MUTATION, THEREFORE THE MOLECULAR MECHANISMS UNDERLYING HOW RUNX1-EVI1 ALONE CONTRIBUTES TO POOR PROGNOSIS ARE UNKNOWN. TO ADDRESS THIS QUESTION, WE INDUCED EXPRESSION OF RUNX1-EVI1 IN HEMATOPOIETIC CELLS DERIVED FROM AN EMBRYONIC STEM CELL DIFFERENTIATION MODEL. INDUCTION RESULTED IN DISRUPTION OF THE RUNX1-DEPENDENT ENDOTHELIAL-HEMATOPOIETIC TRANSITION, BLOCKED THE CELL CYCLE AND UNDERMINED CELL FATE DECISIONS IN MULTIPOTENT HEMATOPOIETIC PROGENITOR CELLS. INTEGRATIVE ANALYSES OF GENE EXPRESSION WITH CHROMATIN AND TRANSCRIPTION FACTOR BINDING DATA DEMONSTRATED THAT RUNX1-EVI1 BINDING CAUSED THE RE-DISTRIBUTION OF ENDOGENOUS RUNX1 WITHIN THE GENOME AND INTERFERED WITH BOTH RUNX1 AND EVI1 REGULATED GENE EXPRESSION PROGRAMS. IN SUMMARY, RUNX1-EVI1 EXPRESSION ALONE LEADS TO EXTENSIVE EPIGENETIC REPROGRAMMING WHICH IS INCOMPATIBLE WITH HEALTHY BLOOD PRODUCTION. 2021 6 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 7 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 8 5004 23 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 9 2696 27 EWING SARCOMA. EWING SARCOMA IS THE SECOND MOST FREQUENT BONE TUMOUR OF CHILDHOOD AND ADOLESCENCE THAT CAN ALSO ARISE IN SOFT TISSUE. EWING SARCOMA IS A HIGHLY AGGRESSIVE CANCER, WITH A SURVIVAL OF 70-80% FOR PATIENTS WITH STANDARD-RISK AND LOCALIZED DISEASE AND ~30% FOR THOSE WITH METASTATIC DISEASE. TREATMENT COMPRISES LOCAL SURGERY, RADIOTHERAPY AND POLYCHEMOTHERAPY, WHICH ARE ASSOCIATED WITH ACUTE AND CHRONIC ADVERSE EFFECTS THAT MAY COMPROMISE QUALITY OF LIFE IN SURVIVORS. HISTOLOGICALLY, EWING SARCOMAS ARE COMPOSED OF SMALL ROUND CELLS EXPRESSING HIGH LEVELS OF CD99. GENETICALLY, THEY ARE CHARACTERIZED BY BALANCED CHROMOSOMAL TRANSLOCATIONS IN WHICH A MEMBER OF THE FET GENE FAMILY IS FUSED WITH AN ETS TRANSCRIPTION FACTOR, WITH THE MOST COMMON FUSION BEING EWSR1-FLI1 (85% OF CASES). EWING SARCOMA BREAKPOINT REGION 1 PROTEIN (EWSR1)-FRIEND LEUKAEMIA INTEGRATION 1 TRANSCRIPTION FACTOR (FLI1) IS A TUMOUR-SPECIFIC CHIMERIC TRANSCRIPTION FACTOR (EWSR1-FLI1) WITH NEOMORPHIC EFFECTS THAT MASSIVELY REWIRES THE TRANSCRIPTOME. ADDITIONALLY, EWSR1-FLI1 REPROGRAMMES THE EPIGENOME BY INDUCING DE NOVO ENHANCERS AT GGAA MICROSATELLITES AND BY ALTERING THE STATE OF GENE REGULATORY ELEMENTS, CREATING A UNIQUE EPIGENETIC SIGNATURE. ADDITIONAL MUTATIONS AT DIAGNOSIS ARE RARE AND MAINLY INVOLVE STAG2, TP53 AND CDKN2A DELETIONS. EMERGING STUDIES ON THE MOLECULAR MECHANISMS OF EWING SARCOMA HOLD PROMISE FOR IMPROVEMENTS IN EARLY DETECTION, DISEASE MONITORING, LOWER TREATMENT-RELATED TOXICITY, OVERALL SURVIVAL AND QUALITY OF LIFE. 2018 10 5433 20 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 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 12 3756 34 INTEGRATED GENOMIC SEQUENCING IN MYELOID BLAST CRISIS CHRONIC MYELOID LEUKEMIA (MBC-CML), IDENTIFIED POTENTIALLY IMPORTANT FINDINGS IN THE CONTEXT OF LEUKEMOGENESIS MODEL. CHRONIC MYELOID LEUKEMIA (CML) IS A MODEL OF LEUKEMOGENESIS IN WHICH THE EXACT MOLECULAR MECHANISMS UNDERLYING BLAST CRISIS STILL REMAINED UNEXPLORED. THE CURRENT STUDY IDENTIFIED MULTIPLE COMMON AND RARE IMPORTANT FINDINGS IN MYELOID BLAST CRISIS CML (MBC-CML) USING INTEGRATED GENOMIC SEQUENCING, COVERING ALL CLASSES OF GENES IMPLICATED IN THE LEUKEMOGENESIS MODEL. INTEGRATED GENOMIC SEQUENCING VIA WHOLE EXOME SEQUENCING (WES), CHROMOSOME-SEQ AND RNA-SEQUENCING WERE CONDUCTED ON THE PERIPHERAL BLOOD SAMPLES OF THREE CML PATIENTS IN THE MYELOID BLAST CRISIS. AN IN-HOUSE FILTERING PIPELINE WAS APPLIED TO ASSESS IMPORTANT VARIANTS IN CANCER-RELATED GENES. STANDARD VARIANT INTERPRETATION GUIDELINES WERE USED FOR THE INTERPRETATION OF POTENTIALLY IMPORTANT FINDINGS (PIFS) AND POTENTIALLY ACTIONABLE FINDINGS (PAFS). SINGLE NUCLEOTIDE VARIATION (SNV) AND SMALL INDEL ANALYSIS BY WES DETECTED SIXTEEN PIFS AFFECTING ALL FIVE KNOWN CLASSES OF LEUKEMOGENIC GENES IN MYELOID MALIGNANCIES INCLUDING SIGNALING PATHWAY COMPONENTS (ABL1, PIK3CB, PTPN11), TRANSCRIPTION FACTORS (GATA2, PHF6, IKZF1, WT1), EPIGENETIC REGULATORS (ASXL1), TUMOR SUPPRESSOR AND DNA REPAIR GENES (BRCA2, ATM, CHEK2) AND COMPONENTS OF SPLICEOSOME (PRPF8). THESE VARIANTS AFFECT GENES INVOLVED IN LEUKEMIA STEM CELL PROLIFERATION, SELF-RENEWAL, AND DIFFERENTIATION. BOTH PATIENTS NO.1 AND NO.2 HAD ACTIONABLE KNOWN MISSENSE VARIANTS ON ABL1 (P.Y272H, P.F359V) AND FRAMESHIFT VARIANTS ON ASXL1 (P.A627GFS*8, P.G646WFS*12). THE GATA2-L359S IN PATIENT NO.1, PTPN11-G503V AND IKZF1-R208Q VARIANTS IN THE PATIENT NO.3 WERE ALSO PAFS. RNA-SEQUENCING WAS USED TO CONFIRM ALL OF THE IDENTIFIED VARIANTS. IN THE PATIENT NO. 3, CHROMOSOME SEQUENCING REVEALED MULTIPLE PATHOGENIC DELETIONS IN THE SHORT AND LONG ARMS OF CHROMOSOME 7, AFFECTING AT LEAST THREE CRITICAL LEUKEMOGENIC GENES (IKZF1, EZH2, AND CUX1). THE LARGE DELETION DISCOVERED ON THE SHORT ARM OF CHROMOSOME 17 IN PATIENT NO. 2 RESULTED IN THE DELETION OF TP53 GENE AS WELL. INTEGRATED GENOMIC SEQUENCING COMBINED WITH RNA-SEQUENCING CAN SUCCESSFULLY DISCOVER AND CONFIRM A WIDE RANGE OF VARIANTS, FROM SNVS TO CNVS. THIS STRATEGY MAY BE AN EFFECTIVE METHOD FOR IDENTIFYING ACTIONABLE FINDINGS AND UNDERSTANDING THE PATHOPHYSIOLOGICAL MECHANISMS UNDERLYING MBC-CML, AS WELL AS PROVIDING FURTHER INSIGHTS INTO THE GENETIC BASIS OF MBC-CML AND ITS MANAGEMENT IN THE FUTURE. 2022 13 2888 32 GAIN-OF-FUNCTION MUTATION OF GATA-2 IN ACUTE MYELOID TRANSFORMATION OF CHRONIC MYELOID LEUKEMIA. ACQUISITION OF ADDITIONAL GENETIC AND/OR EPIGENETIC ABNORMALITIES OTHER THAN THE BCR/ABL FUSION GENE IS BELIEVED TO CAUSE DISEASE PROGRESSION IN CHRONIC MYELOID LEUKEMIA (CML) FROM CHRONIC PHASE TO BLAST CRISIS (BC). TO GAIN INSIGHTS INTO THE UNDERLYING MECHANISMS OF PROGRESSION TO BC, WE SCREENED DNA SAMPLES FROM CML PATIENTS DURING BLAST TRANSFORMATION FOR MUTATIONS IN A NUMBER OF TRANSCRIPTION FACTOR GENES THAT ARE CRITICAL FOR MYELOID-LYMPHOID DEVELOPMENT. IN 85 CASES OF CML BLAST TRANSFORMATION, WE IDENTIFIED TWO NEW MUTATIONS IN THE CODING REGION OF GATA-2, A NEGATIVE REGULATOR OF HEMATOPOIETIC STEM/PROGENITOR CELL DIFFERENTIATION. A L359V SUBSTITUTION WITHIN ZINC FINGER DOMAIN (ZF) 2 OF GATA-2 WAS FOUND IN EIGHT CASES WITH MYELOMONOBLASTIC FEATURES, WHEREAS AN IN-FRAME DELETION OF 6 AA (DELTA341-346) SPANNING THE C-TERMINAL BORDER OF ZF1 WAS DETECTED IN ONE PATIENT AT MYELOID BC WITH EOSINOPHILIA. FURTHER STUDIES INDICATED THAT L359V NOT ONLY INCREASED TRANSACTIVATION ACTIVITY OF GATA-2 BUT ALSO ENHANCED ITS INHIBITORY EFFECTS ON THE ACTIVITY OF PU.1, A MAJOR REGULATOR OF MYELOPOIESIS. CONSISTENT WITH THE MYELOMONOBLASTIC FEATURES OF CML TRANSFORMATION WITH THE GATA-2 L359V MUTANT, TRANSDUCTION OF THE GATA-2 L359V MUTANT INTO HL-60 CELLS OR BCR/ABL-HARBORING MURINE CELLS DISTURBED MYELOMONOCYTIC DIFFERENTIATION/PROLIFERATION IN VITRO AND IN VIVO, RESPECTIVELY. THESE DATA STRONGLY SUGGEST THAT GATA-2 MUTATIONS MAY PLAY A ROLE IN ACUTE MYELOID TRANSFORMATION IN A SUBSET OF CML PATIENTS. 2008 14 3198 29 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 15 3500 32 IDENTIFICATION OF NOVEL, CLONALLY STABLE, SOMATIC MUTATIONS TARGETING TRANSCRIPTION FACTORS PAX5 AND NKX2-3, THE EPIGENETIC REGULATOR LRIF1, AND BRAF IN A CASE OF ATYPICAL B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA HARBORING A T(14;18)(Q32;Q21). DIAGNOSIS OF B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL) IS USUALLY STRAIGHTFORWARD, INVOLVING CLINICAL, IMMUNOPHENOTYPIC (MATUTES SCORE), AND (IMMUNO)GENETIC ANALYSES (TO REFINE PATIENT PROGNOSIS FOR TREATMENT). CLL CASES WITH ATYPICAL PRESENTATION (E.G., MATUTES