1 3520 146 IGLV3-21R110 IDENTIFIES AN AGGRESSIVE BIOLOGICAL SUBTYPE OF CHRONIC LYMPHOCYTIC LEUKEMIA WITH INTERMEDIATE EPIGENETICS. B-CELL RECEPTOR (BCR) SIGNALING IS CRUCIAL FOR CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) BIOLOGY. IGLV3-21-EXPRESSING B CELLS MAY ACQUIRE A SINGLE POINT MUTATION (R110) THAT TRIGGERS AUTONOMOUS BCR SIGNALING, CONFERRING AGGRESSIVE BEHAVIOR. EPIGENETIC STUDIES HAVE DEFINED 3 CLL SUBTYPES BASED ON METHYLATION SIGNATURES REMINISCENT OF NAIVE-LIKE (N-CLL), INTERMEDIATE (I-CLL), AND MEMORY-LIKE (M-CLL) B CELLS WITH DIFFERENT BIOLOGICAL FEATURES. I-CLL CARRIES A BORDERLINE IGHV MUTATIONAL LOAD AND SIGNIFICANTLY HIGHER USE OF IGHV3-21/IGLV3-21. TO DETERMINE THE CLINICAL AND BIOLOGICAL FEATURES OF IGLV3-21R110 CLL AND ITS RELATIONSHIP TO THESE EPIGENETIC SUBTYPES, WE CHARACTERIZED THE IMMUNOGLOBULIN GENE OF 584 CLL CASES USING WHOLE-GENOME/EXOME AND RNA SEQUENCING. IGLV3-21R110 WAS DETECTED IN 6.5% OF CASES: 30 (38%) OF 79 I-CLLS, 5 (1.7%) OF 291 M-CLLS, AND 1 (0.5%) OF 189 N-CLLS. ALL STEREOTYPE SUBSET 2 CASES CARRIED IGLV3-21R110, WHEREAS 62% OF IGLV3-21R110 I-CLL CASES HAD NONSTEREOTYPED BCR IMMUNOGLOBULINS. IGLV3-21R110 I-CLL HAD A SIGNIFICANTLY HIGHER NUMBER OF SF3B1 AND ATM MUTATIONS AND TOTAL NUMBER OF DRIVER ALTERATIONS. HOWEVER, THE R110 MUTATION WAS THE SOLE ALTERATION IN 1 I-CLL AND WAS ACCOMPANIED ONLY BY DEL(13Q) IN 3. ALTHOUGH IGHV MUTATIONAL STATUS VARIED, IGLV3-21R110 I-CLL TRANSCRIPTOMICALLY RESEMBLED N-CLL/UNMUTATED IGHV CLL WITH A SPECIFIC SIGNATURE INCLUDING WNT5A/B OVEREXPRESSION. IN CONTRAST, I-CLL LACKING IGLV3-21R110 MIRRORED M-CLL/MUTATED IGHV. PATIENTS WITH IGLV3-21R110 I-CLL HAD A SHORT TIME TO FIRST TREATMENT AND OVERALL SURVIVAL SIMILAR TO THOSE OF N-CLL/UNMUTATED IGHV PATIENTS, WHEREAS PATIENTS WITH NON-IGLV3-21R110 I-CLL HAD A GOOD PROGNOSIS SIMILAR TO THAT OF PATIENTS WITH M-CLL/MUTATED IGHV. IGLV3-21R110 DEFINES A CLL SUBGROUP WITH SPECIFIC BIOLOGICAL FEATURES AND AN UNFAVORABLE PROGNOSIS INDEPENDENT OF IGHV MUTATIONAL STATUS AND EPIGENETIC SUBTYPE. 2021 2 2696 31 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 3 5848 31 SUBCLONES IN B-LYMPHOMA CELL LINES: ISOGENIC MODELS FOR THE STUDY OF GENE REGULATION. GENETIC HETEROGENEITY THOUGH COMMON IN TUMORS HAS BEEN RARELY DOCUMENTED IN CELL LINES. TO EXAMINE HOW OFTEN B-LYMPHOMA CELL LINES ARE COMPRISED OF SUBCLONES, WE PERFORMED IMMUNOGLOBULIN (IG) HEAVY CHAIN HYPERMUTATION ANALYSIS. REVEALING THAT SUBCLONES ARE NOT RARE IN B-CELL LYMPHOMA CELL LINES, 6/49 IG HYPERMUTATED CELL LINES (12%) CONSISTED OF SUBCLONES WITH INDIVIDUAL IG MUTATIONS. SUBCLONES WERE ALSO IDENTIFIED IN 2/284 LEUKEMIA/LYMPHOMA CELL LINES EXHIBITING BIMODAL CD MARKER EXPRESSION. WE SUCCESSFULLY ISOLATED 10 SUBCLONES FROM FOUR CELL LINES (HG3, SU-DHL-5, TMD-8, U-2932). WHOLE EXOME SEQUENCING WAS PERFORMED TO MOLECULARLY CHARACTERIZE THESE SUBCLONES. WE DESCRIBE IN DETAIL THE CLONAL STRUCTURE OF CELL LINE HG3, DERIVED FROM CHRONIC LYMPHOCYTIC LEUKEMIA. HG3 CONSISTS OF THREE SUBCLONES EACH BEARING CLONE-SPECIFIC ABERRATIONS, GENE EXPRESSION AND DNA METHYLATION PATTERNS. WHILE DONOR PATIENT LEUKEMIC CELLS WERE CD5+, TWO OF THREE HG3 SUBCLONES HAD INDEPENDENTLY LOST THIS MARKER. CD5 ON HG3 CELLS WAS REGULATED BY EPIGENETIC/TRANSCRIPTIONAL MECHANISMS RATHER THAN BY ALTERNATIVE SPLICING AS REPORTED HITHERTO. IN CONCLUSION, WE SHOW THAT THE PRESENCE OF SUBCLONES IN CELL LINES CARRYING INDIVIDUAL MUTATIONS AND CHARACTERIZED BY SETS OF DIFFERENTIALLY EXPRESSED GENES IS NOT UNCOMMON. WE SHOW ALSO THAT THESE SUBCLONES CAN BE USEFUL ISOGENIC MODELS FOR REGULATORY AND FUNCTIONAL STUDIES. 2016 4 4432 31 MOLECULAR CHARACTERIZATION OF RICHTER SYNDROME IDENTIFIES DE NOVO DIFFUSE LARGE B-CELL LYMPHOMAS WITH POOR PROGNOSIS. RICHTER SYNDROME (RS) IS THE TRANSFORMATION OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) INTO AGGRESSIVE LYMPHOMA, MOST COMMONLY DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL). WE CHARACTERIZE 58 PRIMARY HUMAN RS SAMPLES BY GENOME-WIDE DNA METHYLATION AND WHOLE-TRANSCRIPTOME PROFILING. OUR COMPREHENSIVE APPROACH DETERMINES RS DNA METHYLATION PROFILE AND UNRAVELS A CLL EPIGENETIC IMPRINT, ALLOWING CLL-RS CLONAL RELATIONSHIP ASSESSMENT WITHOUT THE NEED OF THE INITIAL CLL TUMOR DNA. DNA METHYLATION- AND TRANSCRIPTOMIC-BASED CLASSIFIERS WERE DEVELOPED, AND TESTING ON LANDMARK DLBCL DATASETS IDENTIFIES A POOR-PROGNOSIS, ACTIVATED B-CELL-LIKE DLBCL SUBSET IN 111/1772 SAMPLES. THE CLASSIFICATION ROBUSTLY IDENTIFIES PHENOTYPES VERY SIMILAR TO RS WITH A SPECIFIC GENOMIC PROFILE, ACCOUNTING FOR 4.3-8.3% OF DE NOVO DLBCLS. IN THIS WORK, RS MULTI-OMICS CHARACTERIZATION DETERMINES ONCOGENIC MECHANISMS, ESTABLISHES A SURROGATE MARKER FOR CLL-RS CLONAL RELATIONSHIP, AND PROVIDES A CLINICALLY RELEVANT CLASSIFIER FOR A SUBSET OF PRIMARY "RS-TYPE DLBCL" WITH UNFAVORABLE PROGNOSIS. 2023 5 5909 27 TARGETED DEEP SEQUENCING OF PLASMA CIRCULATING CELL-FREE DNA REVEALS VIMENTIN AND FIBULIN 1 AS POTENTIAL EPIGENETIC BIOMARKERS FOR HEPATOCELLULAR CARCINOMA. HEPATOCELLULAR CARCINOMA (HCC) IS THE SECOND MOST COMMON CAUSE OF CANCER DEATH WORLDWIDE, BUT IS STILL LACKING SENSITIVE AND SPECIFIC BIOMARKERS FOR EARLY DIAGNOSIS AND PROGNOSIS. IN THIS STUDY, WE APPLIED TARGETED MASSIVELY PARALLEL SEMICONDUCTOR SEQUENCING TO ASSESS METHYLATION ON A PANEL OF GENES (FBLN1, HINT2, LAMC1, LTBP1, LTBP2, PSMA2, PSMA7, PXDN, TGFB1, UBE2L3, VIM AND YWHAZ) IN PLASMA CIRCULATING CELL-FREE DNA (CFDNA) AND TO EVALUATE THE POTENTIAL OF THESE GENES AS HCC BIOMARKERS IN TWO DIFFERENT SERIES, ONE FROM FRANCE (42 HCC CASES AND 42 CONTROLS) AND ONE FROM THAILAND (42 HCC CASES, 26 CHRONIC LIVER DISEASE CASES AND 42 CONTROLS). WE ALSO ANALYZED A SET OF HCC AND ADJACENT TISSUES AND LIVER CELL LINES TO FURTHER COMPARE WITH 'THE CANCER GENOME ATLAS' (TCGA) DATA. THE METHYLATION IN CFDNA WAS DETECTED FOR FBLN1, PSMA7, PXDN AND VIM, WITH DIFFERENCES IN METHYLATION PATTERNS BETWEEN CASES AND CONTROLS FOR FBLN1 AND VIM. THE AVERAGE METHYLATION LEVEL ACROSS ANALYZED CPG-SITES WAS ASSOCIATED WITH HIGHER ODDS OF HCC FOR VIM (1.48 [1.02, 2.16] FOR FRENCH CASES AND 2.18 [1.28, 3.72] FOR THAI CASES), AND LOWER ODDS OF HCC FOR FBLN1 (0.89 [0.76, 1.03] FOR FRENCH CASES AND 0.75 [0.63, 0.88] FOR THAI CASES). IN CONCLUSION, OUR STUDY PROVIDES EVIDENCE THAT CHANGES IN VIM AND FBLN1 METHYLATION LEVELS IN CFDNA ARE ASSOCIATED WITH HCC AND COULD REPRESENT USEFUL PLASMA-BASED BIOMARKERS. ALSO, THE POTENTIAL TO INVESTIGATE METHYLATION PATTERNS IN CFDNA COULD BRING NEW STRATEGIES FOR HCC DETECTION AND MONITORING HIGH-RISK GROUPS AND RESPONSE TO TREATMENT. 2017 6 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 7 3500 36 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 100 BISULFITE PCR PRODUCTS IN A SINGLE SEQUENCING RUN WITHOUT SUBCLONING. WE SHOWED THE UTILITY, ROBUSTNESS, AND SUPERIORITY OF THIS APPROACH BY ANALYZING METHYLATION IN 25 GENE-RELATED CPG RICH REGIONS FROM >40 CASES OF PRIMARY CELLS, INCLUDING NORMAL PERIPHERAL BLOOD LYMPHOCYTES, ACUTE LYMPHOBLASTIC LEUKEMIA (ALL), CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), FOLLICULAR LYMPHOMA (FL), AND MANTLE CELL LYMPHOMA (MCL). A TOTAL OF 294,631 SEQUENCES WAS GENERATED WITH AN AVERAGE READ LENGTH OF 131 BP. ON AVERAGE, >1,600 INDIVIDUAL SEQUENCES WERE GENERATED FOR EACH PCR AMPLICON FAR BEYOND THE FEW CLONES (<20) TYPICALLY ANALYZED BY TRADITIONAL BISULFITE SEQUENCING. COMPREHENSIVE ANALYSIS OF CPG METHYLATION PATTERNS AT A SINGLE DNA MOLECULE LEVEL USING CLUSTERING ALGORITHMS REVEALED DIFFERENTIAL METHYLATION PATTERNS BETWEEN DISEASES. A SIGNIFICANT INCREASE IN METHYLATION WAS DETECTED IN ALL AND FL SAMPLES COMPARED WITH CLL AND MCL. FURTHERMORE, A PROGRESSIVE SPREADING OF METHYLATION WAS DETECTED FROM THE PERIPHERY TOWARD THE CENTER OF SELECT CPG ISLANDS IN THE ALL AND FL SAMPLES. THE ULTRADEEP SEQUENCING ALSO ALLOWED SIMULTANEOUS ANALYSIS OF GENETIC AND EPIGENETIC DATA AND REVEALED AN ASSOCIATION BETWEEN A SINGLE NUCLEOTIDE POLYMORPHISM AND THE METHYLATION PRESENT IN THE LRP1B PROMOTER. THIS NEW GENERATION OF METHYLOME SEQUENCING WILL PROVIDE DIGITAL PROFILES OF ABERRANT DNA METHYLATION FOR INDIVIDUAL HUMAN CANCERS AND OFFERS A ROBUST METHOD FOR THE EPIGENETIC CLASSIFICATION OF TUMOR SUBTYPES. 2007 11 4566 20 MYELOID SOMATIC MUTATION PANEL TESTING IN MYELOPROLIFERATIVE NEOPLASMS. MYELOPROLIFERATIVE NEOPLASMS ARE CHARACTERISED BY SOMATIC MUTATIONS IN PATHWAYS THAT REGULATE CELL PROLIFERATION, EPIGENETIC MODIFICATIONS, RNA SPLICING OR DNA REPAIR. ASSESSMENT OF THE MUTATIONAL PROFILE ASSISTS DIAGNOSIS AND CLASSIFICATION, BUT ALSO AIDS ASSESSMENT OF PROGNOSIS, AND MAY GUIDE THE USE OF EMERGING TARGETED THERAPIES. THE MOST PRACTICAL WAY TO PROVIDE INFORMATION ON NUMEROUS GENETIC VARIANTS IS BY USING MASSIVELY PARALLEL SEQUENCING, COMMONLY IN THE FORM OF DISEASE SPECIFIC NEXT GENERATION SEQUENCING (NGS) PANELS. THIS REVIEW SUMMARISES THE DIAGNOSTIC AND PROGNOSTIC VALUE OF SOMATIC MUTATION TESTING IN PHILADELPHIA-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS: POLYCYTHAEMIA VERA, ESSENTIAL THROMBOCYTHAEMIA, PRIMARY MYELOFIBROSIS, CHRONIC NEUTROPHILIC LEUKAEMIA, SYSTEMIC MASTOCYTOSIS, AND CHRONIC EOSINOPHILIC LEUKAEMIA. NGS PANEL TESTING IS INCREASING IN ROUTINE PRACTICE AND PROMISES TO IMPROVE THE ACCURACY AND EFFICIENCY OF PATHOLOGICAL DIAGNOSIS AND PROGNOSIS. 2021 12 2431 34 EPIGENETIC SILENCING OF MIR-26A1 IN CHRONIC LYMPHOCYTIC LEUKEMIA AND MANTLE CELL LYMPHOMA: IMPACT ON EZH2 EXPRESSION. DOWNREGULATION OF MIR26A1 HAS BEEN REPORTED IN VARIOUS B-CELL MALIGNANCIES; HOWEVER, THE MECHANISM BEHIND ITS DEREGULATION REMAINS LARGELY UNKNOWN. WE INVESTIGATED MIR26A1 METHYLATION AND EXPRESSION LEVELS IN A WELL-CHARACTERIZED SERIES OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND MANTLE CELL LYMPHOMA (MCL). FROM 450K METHYLATION ARRAYS, WE FIRST OBSERVED MIR26A1 (CG26054057) AS UNIFORMLY HYPERMETHYLATED IN MCL (N = 24) (ALL >75%), WHILE CLL (N = 18) SHOWED DIFFERENTIAL METHYLATION BETWEEN PROGNOSTIC SUBGROUPS. EXTENDED ANALYSIS USING PYROSEQUENCING CONFIRMED OUR FINDINGS AND REAL-TIME QUANTITATIVE PCR VERIFIED LOW MIR26A1 EXPRESSION IN BOTH CLL (N = 70) AND MCL (N = 38) COMPARED TO NORMAL B-CELLS. NOTABLY, THE LEVEL OF MIR26A1 METHYLATION PREDICTED OUTCOME IN CLL, WITH HIGHER LEVELS SEEN IN POOR-PROGNOSTIC, IGHV-UNMUTATED CLL. SINCE EZH2 WAS RECENTLY REPORTED AS A TARGET FOR MIR26A1, WE ANALYZED THE EXPRESSION LEVELS OF BOTH MIR26A1 AND EZH2 IN PRIMARY CLL SAMPLES AND OBSERVED AN INVERSE CORRELATION. BY OVEREXPRESSION OF MIR26A1 IN CLL AND MCL CELL LINES, REDUCED EZH2 PROTEIN LEVELS WERE OBSERVED USING BOTH WESTERN BLOT AND FLOW CYTOMETRY. IN CONTRAST, METHYL-INHIBITOR TREATMENT LED TO UPREGULATED MIR26A1 EXPRESSION WITH A PARALLEL DECREASE OF EZH2 EXPRESSION. FINALLY, INCREASED LEVELS OF APOPTOSIS WERE OBSERVED IN MIR26A1-OVEREXPRESSING CELL LINES, FURTHER UNDERSCORING THE FUNCTIONAL RELEVANCE OF MIR26A1. IN SUMMARY, WE PROPOSE THAT EPIGENETIC SILENCING OF MIR26A1 IS REQUIRED FOR THE MAINTENANCE OF INCREASED LEVELS OF EZH2, WHICH IN TURN TRANSLATE INTO A WORSE OUTCOME, AS SHOWN IN CLL, HIGHLIGHTING MIR26A1 AS A TUMOR SUPPRESSOR MIRNA. 2016 13 4549 23 MUTATION ANALYSIS OF THERAPY-RELATED MYELOID NEOPLASMS. WE ANALYZED THE GENETIC MUTATION STATUS OF 13 PATIENTS WITH THERAPY-RELATED MYELOID NEOPLASMS (T-MN). CONSISTENT WITH PREVIOUS REPORTS, T-MN CELLS PREFERENTIALLY ACQUIRED MUTATIONS IN TP53 AND EPIGENETIC MODIFYING GENES, INSTEAD OF MUTATIONS IN TYROSINE KINASE AND SPLICEOSOME GENES. FURTHERMORE, WE COMPARED THE MUTATION STATUS OF THREE T-MN CELLS WITH EACH OF THE INITIAL LYMPHOID MALIGNANT CELLS, AND IDENTIFIED COMMON MUTATIONS AMONG T-MN AND THE INITIAL MALIGNANT CELLS IN TWO PATIENTS. IN A PATIENT WHO DEVELOPED CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AFTER FOLLICULAR LYMPHOMA (FL), TET2 MUTATION WAS IDENTIFIED IN BOTH CMML AND FL CELLS. NOTABLY, THE TET2 MUTATION WAS ALSO IDENTIFIED IN PERIPHERAL BLOOD CELLS IN THE DISEASE-FREE PERIOD WITH THE SAME ALLELIC FREQUENCY AS CMML AND FL CELLS, BUT NOT IN A GERM-LINE CONTROL, INDICATING THAT THE TET2 MUTATION OCCURRED SOMATICALLY IN THE INITIATING CLONE FOR BOTH MALIGNANT CELLS. ON THE OTHER HAND, A GERM-LINE MYB MUTATION WAS IDENTIFIED IN A PATIENT WHO DEVELOPED MYELODYSPLASTIC SYNDROMES (MDS) AFTER FL. THESE RESULTS SUGGEST THAT GERM-LINE DEPOSITION AND CLONAL HEMATOPOIESIS ARE CLOSELY ASSOCIATED WITH T-MN SUSCEPTIBILITY; HOWEVER, FURTHER ANALYSIS IS NECESSARY TO CLARIFY THE MECHANISM REQUIRED TO PROVIDE THE INITIATING CLONE WITH LINEAGE COMMITMENT AND CLONAL EXPANSION. 2018 14 5911 23 TARGETED NEXT-GENERATION SEQUENCING IN MYELODYSPLASTIC SYNDROME AND CHRONIC MYELOMONOCYTIC LEUKEMIA AIDS DIAGNOSIS IN CHALLENGING CASES AND IDENTIFIES FREQUENT SPLICEOSOME MUTATIONS IN TRANSFORMED ACUTE MYELOID LEUKEMIA. OBJECTIVES: OPTIMAL INTEGRATION OF NEXT-GENERATION SEQUENCING (NGS) INTO CLINICAL PRACTICE IN HEMATOLOGIC MALIGNANCIES REMAINS UNCLEAR. WE EVALUATE THE UTILITY OF NGS IN MYELOID MALIGNANCIES. METHODS: A 42-GENE PANEL WAS USED TO SEQUENCE 109 CASES OF MYELODYSPLASTIC SYNDROME (MDS, N = 38), CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML, N = 14), MYELOPROLIFERATIVE NEOPLASM (MPN, N = 24), AND MDS AND/OR MPN TRANSFORMED TO ACUTE MYELOID LEUKEMIA (AML, N = 33). RESULTS: AT LEAST ONE PATHOGENIC MUTATION WAS IDENTIFIED IN 74% OF CASES OF MDS, 100% OF CMMLS, AND 96% OF MPNS. IN CONTRAST, ONLY 47% OF CASES OF MDS (18/38) AND 7% (1/14) OF CMMLS EXHIBITED ABNORMAL CYTOGENETICS. IN DIAGNOSTICALLY DIFFICULT CASES OF MDS OR CMML WITH NORMAL CYTOGENETICS, NGS IDENTIFIED A PATHOGENIC MUTATION AND WAS CRITICAL IN ESTABLISHING THE CORRECT DIAGNOSIS. SPLICEOSOMAL GENES AND EPIGENETIC MODIFIERS WERE FREQUENTLY MUTATED. SPLICEOSOME MUTATIONS WERE ALSO FREQUENTLY DETECTED IN AML ARISING FROM MDS, CMML, OR MPN (39%) COMPARED WITH THE REPORTED RATE IN DE NOVO AML (7%-14%). CONCLUSIONS: IN DIFFICULT CASES OF MDS OR MPN, NGS FACILITATES DIAGNOSIS BY DETECTION OF GENE MUTATIONS TO CONFIRM CLONALITY, AND AMLS EVOLVING FROM MDS OR MPN CARRY FREQUENT MUTATIONS IN SPLICEOSOMAL GENES. 2016 15 3091 28 GENOMIC AND EPIGENOMIC HETEROGENEITY IN CHRONIC LYMPHOCYTIC LEUKEMIA. DEFINING FEATURES OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) ARE NOT ONLY ITS IMMUNOPHENOTYPE OF CD19(+)CD5(+)CD23(+)SIGDIM EXPRESSING CLONAL MATURE B CELLS BUT ALSO ITS HIGHLY VARIABLE CLINICAL COURSE. IN RECENT YEARS, ADVANCES IN MASSIVELY PARALLEL SEQUENCING TECHNOLOGIES HAVE LED TO RAPID PROGRESS IN OUR UNDERSTANDING OF THE CLL GENOME AND EPIGENOME. OVERALL, THESE STUDIES HAVE CLEARLY DEMARCATED NOT ONLY THE VAST DEGREE OF GENETIC AND EPIGENETIC HETEROGENEITY AMONG INDIVIDUALS WITH CLL BUT ALSO EVEN WITHIN INDIVIDUAL PATIENT LEUKEMIAS. WE HEREIN REVIEW THE RAPIDLY GROWING SERIES OF STUDIES ASSESSING THE GENETIC AND EPIGENETIC FEATURES OF CLL WITHIN CLINICALLY DEFINED PERIODS OF ITS GROWTH. THESE STUDIES STRONGLY SUGGEST AN EVOLVING SPECTRUM OF LESIONS OVER TIME AND THAT THESE FEATURES MAY HAVE CLINICAL IMPACT. 2015 16 628 41 BIOLOGICAL AND CLINICAL INSIGHT FROM ANALYSIS OF THE TUMOR B-CELL RECEPTOR STRUCTURE AND FUNCTION IN CHRONIC LYMPHOCYTIC LEUKEMIA. THE B-CELL RECEPTOR (BCR) IS ESSENTIAL TO THE BEHAVIOR OF THE MAJORITY OF NORMAL AND NEOPLASTIC MATURE B CELLS. THE IDENTIFICATION IN 1999 OF THE TWO MAJOR CLL SUBSETS EXPRESSING UNMUTATED IMMUNOGLOBULIN (IG) VARIABLE REGION GENES (U-IGHV, U-CLL) OF PRE-GERMINAL CENTER ORIGIN AND POOR PROGNOSIS, AND MUTATED IGHV (M-CLL) OF POST-GERMINAL CENTER ORIGIN AND GOOD PROGNOSIS, IGNITED INTENSIVE INVESTIGATIONS ON STRUCTURE AND FUNCTION OF THE TUMOR BCR. THESE INVESTIGATIONS HAVE PROVIDED FUNDAMENTAL INSIGHT INTO CLL BIOLOGY AND EVENTUALLY THE MECHANISTIC RATIONALE FOR THE DEVELOPMENT OF SUCCESSFUL THERAPIES TARGETING BCR SIGNALING. U-CLL AND M-CLL ARE CHARACTERIZED BY VARIABLE LOW SURFACE IGM (SIGM) EXPRESSION AND SIGNALING CAPACITY. VARIABILITY OF SIGM CAN IN PART BE EXPLAINED BY CHRONIC ENGAGEMENT WITH (AUTO)ANTIGEN AT TISSUE SITES. HOWEVER, OTHER ENVIRONMENTAL ELEMENTS, GENETIC CHANGES, AND EPIGENETIC SIGNATURES ALSO CONTRIBUTE TO THE SIGM VARIABILITY. THE VARIABLE LEVELS HAVE CONSEQUENCES ON THE BEHAVIOR OF CLL, WHICH IS IN A STATE OF ANERGY WITH AN INDOLENT CLINICAL COURSE WHEN SIGM EXPRESSION IS LOW, OR PUSHED TOWARDS PROLIFERATION AND A MORE AGGRESSIVE CLINICAL COURSE WHEN SIGM EXPRESSION IS HIGH. EFFICACY OF THERAPIES THAT TARGET BTK MAY ALSO BE AFFECTED BY THE VARIABLE SIGM LEVELS AND SIGNALING AND, IN PART, EXPLAIN THE DEVELOPMENT OF RESISTANCE. 2022 17 829 28 CHARACTERIZATION OF P190-BCR-ABL CHRONIC MYELOID LEUKEMIA REVEALS SPECIFIC SIGNALING PATHWAYS AND THERAPEUTIC TARGETS. THE ONCOGENIC PROTEIN BCR-ABL HAS TWO MAJOR ISOFORMS, P190(BCR-ABL) AND P210(BCR-ABL). WHILE P210(BCR-ABL) IS THE HALLMARK OF CHRONIC MYELOID LEUKEMIA (CML), P190(BCR-ABL) OCCURS IN THE MAJORITY OF PHILADELPHIA-POSITIVE ACUTE LYMPHOBLASTIC LEUKEMIA (PH + ALL) PATIENTS. IN CML, P190(BCR-ABL) OCCURS IN A MINORITY OF PATIENTS ASSOCIATING WITH DISTINCT HEMATOLOGICAL FEATURES AND INFERIOR OUTCOMES, YET THE PATHOGENIC ROLE OF P190(BCR-ABL) AND POTENTIAL TARGETING THERAPIES ARE LARGELY UNCHARACTERIZED. WE EMPLOYED NEXT GENERATION SEQUENCING, PHOSPHO-PROTEOMIC PROFILING, AND DRUG SENSITIVITY TESTING TO CHARACTERIZE P190(BCR-ABL) IN CML AND HEMATOPOIETIC PROGENITOR CELL LINE MODELS (BA/F3 AND HPC-LSK). P190(BCR-ABL) CML PATIENTS DEMONSTRATED POOR RESPONSE TO IMATINIB AND FREQUENT MUTATIONS IN EPIGENETIC MODIFIERS GENES. IN CONTRAST WITH P210(BCR-ABL), P190(BCR-ABL) EXHIBITED SPECIFIC TRANSCRIPTIONAL UPREGULATION OF INTERFERON, INTERLEUKIN-1 RECEPTOR, AND P53 SIGNALING PATHWAYS, ASSOCIATED WITH HYPERPHOSPHORYLATION OF RELEVANT SIGNALING MOLECULES INCLUDING JAK1/STAT1 AND PAK1 IN ADDITION TO SRC HYPERPHOSPHORYLATION. COMPARABLE TO P190(BCR-ABL) CML PATIENTS, P190(BCR-ABL) CELL LINES DEMONSTRATED SIMILAR TRANSCRIPTIONAL AND PHOSPHO-SIGNALING SIGNATURES. WITH THE DRUG SENSITIVITY SCREENING WE IDENTIFIED TARGETED DRUGS WITH SPECIFIC ACTIVITY IN P190(BCR-ABL) CELL LINES INCLUDING IAP-, PAK1-, AND SRC INHIBITORS AND GLUCOCORTICOIDS. OUR RESULTS PROVIDE NOVEL INSIGHTS INTO THE MECHANISMS UNDERLYING THE DISTINCT FEATURES OF P190(BCR-ABL) CML AND PROMISING THERAPEUTIC TARGETS FOR THIS HIGH-RISK PATIENT GROUP. 2021 18 62 27 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 19 6709 28 VIRAL TRANSDUCTION OF PRIMARY HUMAN LYMPHOMA B CELLS REVEALS MECHANISMS OF NOTCH-MEDIATED IMMUNE ESCAPE. HOTSPOT MUTATIONS IN THE PEST-DOMAIN OF NOTCH1 AND NOTCH2 ARE RECURRENTLY IDENTIFIED IN B CELL MALIGNANCIES. TO ADDRESS HOW NOTCH-MUTATIONS CONTRIBUTE TO A DISMAL PROGNOSIS, WE HAVE GENERATED ISOGENIC PRIMARY HUMAN TUMOR CELLS FROM PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND MANTLE CELL LYMPHOMA (MCL), DIFFERING ONLY IN THEIR EXPRESSION OF THE INTRACELLULAR DOMAIN (ICD) OF NOTCH1 OR NOTCH2. OUR DATA DEMONSTRATE THAT BOTH NOTCH-PARALOGS FACILITATE IMMUNE-ESCAPE OF MALIGNANT B CELLS BY UP-REGULATING PD-L1, PARTLY DEPENDENT ON AUTOCRINE INTERFERON-GAMMA SIGNALING. IN ADDITION, NOTCH-ACTIVATION CAUSES SILENCING OF THE ENTIRE HLA-CLASS II LOCUS VIA EPIGENETIC REGULATION OF THE TRANSCRIPTIONAL CO-ACTIVATOR CIITA. NOTABLY, WHILE NOTCH1 AND NOTCH2 GOVERN SIMILAR TRANSCRIPTIONAL PROGRAMS, DISEASE-SPECIFIC DIFFERENCES IN THEIR EXPRESSION LEVELS CAN FAVOR PARALOG-SPECIFIC SELECTION. IMPORTANTLY, NOTCH-ICD ALSO STRONGLY DOWN-REGULATES THE EXPRESSION OF CD19, POSSIBLY LIMITING THE EFFECTIVENESS OF IMMUNE-THERAPIES. THESE NOTCH-MEDIATED IMMUNE ESCAPE MECHANISMS ARE ASSOCIATED WITH THE EXPANSION OF EXHAUSTED CD8(+) T CELLS IN VIVO. 2022 20 1281 22 DECIPHERING NEURODEGENERATIVE DISEASES USING LONG-READ SEQUENCING. NEURODEGENERATIVE DISEASES EXHIBIT CHRONIC PROGRESSIVE LESIONS IN THE CENTRAL AND PERIPHERAL NERVOUS SYSTEMS WITH UNCLEAR CAUSES. THE SEARCH FOR PATHOGENIC MUTATIONS IN HUMAN NEURODEGENERATIVE DISEASES HAS BENEFITED FROM MASSIVELY PARALLEL SHORT-READ SEQUENCERS. HOWEVER, GENOMIC REGIONS, INCLUDING REPETITIVE ELEMENTS, ESPECIALLY WITH HIGH/LOW GC CONTENT, ARE FAR BEYOND THE CAPABILITY OF CONVENTIONAL APPROACHES. RECENTLY, LONG-READ SINGLE-MOLECULE DNA SEQUENCING TECHNOLOGIES HAVE EMERGED AND ENABLED RESEARCHERS TO STUDY GENOMES, TRANSCRIPTOMES, AND METAGENOMES AT UNPRECEDENTED RESOLUTIONS. THE IDENTIFICATION OF NOVEL MUTATIONS IN UNRESOLVED NEURODEGENERATIVE DISORDERS, THE CHARACTERIZATION OF CAUSATIVE REPEAT EXPANSIONS, AND THE DIRECT DETECTION OF EPIGENETIC MODIFICATIONS ON NAIVE DNA BY VIRTUE OF LONG-READ SEQUENCERS WILL FURTHER EXPAND OUR UNDERSTANDING OF NEURODEGENERATIVE DISEASES. IN THIS ARTICLE, WE REVIEW AND COMPARE 2 PREVAILING LONG-READ SEQUENCING TECHNOLOGIES, PACIFIC BIOSCIENCES AND OXFORD NANOPORE TECHNOLOGIES, AND DISCUSS THEIR APPLICATIONS IN NEURODEGENERATIVE DISEASES. 2021