Somatic Mutations in Variant and IGHV4-34 Expressing Hairy Cell Leukemia
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ABSTRACT: To understand the genetic mechanisms driving variant and IGHV4-34 expressing hairy-cell leukemia, we performed whole exome sequencing of tumor/normal pairs from ten patients.
SECONDARY ACCESSION(S): PRJNA223180PRJNA223178
REPOSITORIES: dbGaP
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Project description:<p>To understand the genetic mechanisms driving variant and IGHV4-34 expressing hairy-cell leukemia, we performed whole exome sequencing of tumor/normal pairs from ten patients.</p>
| phs000671.v1.p1 | EGA
Project description:Somatic mutations in variant and IGHV4-34 expressing hairy cell leukemia
| PRJNA223180 | ENA
Project description:Somatic mutations in variant and IGHV4-34 expressing hairy cell leukemia
| PRJNA223178 | ENA
Project description:BackgroundT-cell large granular lymphocytic leukemia is a rare lymphoproliferative disorder characterized by the expansion of clonal CD3+CD8+ cytotoxic T lymphocytes (CTLs) and often associated with autoimmune disorders and immune-mediated cytopenias.MethodsWe used next-generation exome sequencing to identify somatic mutations in CTLs from an index patient with large granular lymphocytic leukemia. Targeted resequencing was performed in a well-characterized cohort of 76 patients with this disorder, characterized by clonal T-cell-receptor rearrangements and increased numbers of large granular lymphocytes.ResultsMutations in the signal transducer and activator of transcription 3 gene (STAT3) were found in 31 of 77 patients (40%) with large granular lymphocytic leukemia. Among these 31 patients, recurrent mutational hot spots included Y640F in 13 (17%), D661V in 7 (9%), D661Y in 7 (9%), and N647I in 3 (4%). All mutations were located in exon 21, encoding the Src homology 2 (SH2) domain, which mediates the dimerization and activation of STAT protein. The amino acid changes resulted in a more hydrophobic protein surface and were associated with phosphorylation of STAT3 and its localization in the nucleus. In vitro functional studies showed that the Y640F and D661V mutations increased the transcriptional activity of STAT3. In the affected patients, downstream target genes of the STAT3 pathway (IFNGR2, BCL2L1, and JAK2) were up-regulated. Patients with STAT3 mutations presented more often with neutropenia and rheumatoid arthritis than did patients without these mutations.ConclusionsThe SH2 dimerization and activation domain of STAT3 is frequently mutated in patients with large granular lymphocytic leukemia; these findings suggest that aberrant STAT3 signaling underlies the pathogenesis of this disease. (Funded by the Academy of Finland and others.).
| S-EPMC3693860 | biostudies-literature
Project description:The pattern of somatic mutations observed at diagnosis of acute myeloid leukemia (AML) has been well-characterized. However, the premalignant mutational landscape of AML and its impact on risk and time to diagnosis is unknown. Here we identified 212 women from the Women's Health Initiative who were healthy at study baseline, but eventually developed AML during follow-up (median time: 9.6 years). Deep sequencing was performed on peripheral blood DNA of these cases and compared to age-matched controls that did not develop AML. We discovered that mutations in IDH1, IDH2, TP53, DNMT3A, TET2 and spliceosome genes significantly increased the odds of developing AML. All subjects with TP53 mutations (n = 21 out of 21 patients) and IDH1 and IDH2 (n = 15 out of 15 patients) mutations eventually developed AML in our study. The presence of detectable mutations years before diagnosis suggests that there is a period of latency that precedes AML during which early detection, monitoring and interventional studies should be considered.
| S-EPMC6849383 | biostudies-literature
Project description:Acute myeloid leukemia (AML) can develop after an antecedent myeloid malignancy (secondary AML [s-AML]), after leukemogenic therapy (therapy-related AML [t-AML]), or without an identifiable prodrome or known exposure (de novo AML). The genetic basis of these distinct pathways of AML development has not been determined. We performed targeted mutational analysis of 194 patients with rigorously defined s-AML or t-AML and 105 unselected AML patients. The presence of a mutation in SRSF2, SF3B1, U2AF1, ZRSR2, ASXL1, EZH2, BCOR, or STAG2 was >95% specific for the diagnosis of s-AML. Analysis of serial samples from individual patients revealed that these mutations occur early in leukemogenesis and often persist in clonal remissions. In t-AML and elderly de novo AML populations, these alterations define a distinct genetic subtype that shares clinicopathologic properties with clinically confirmed s-AML and highlights a subset of patients with worse clinical outcomes, including a lower complete remission rate, more frequent reinduction, and decreased event-free survival. This trial was registered at www.clinicaltrials.gov as #NCT00715637.
| S-EPMC4342352 | biostudies-literature
Project description:Large granular lymphocytic (LGL) leukemia is characterized by clonal expansion of cytotoxic T cells or natural killer cells. Recently, somatic mutations in the signal transducer and activator of transcription 3 (STAT3) gene were discovered in 28% to 40% of LGL leukemia patients. By exome and transcriptome sequencing of 2 STAT3 mutation-negative LGL leukemia patients, we identified a recurrent, somatic missense mutation (Y665F) in the Src-like homology 2 domain of the STAT5b gene. Targeted amplicon sequencing of 211 LGL leukemia patients revealed 2 additional patients with STAT5b mutations (N642H), resulting in a total frequency of 2% (4 of 211) of STAT5b mutations across all patients. The Y665F and N642H mutant constructs increased the transcriptional activity of STAT5 and tyrosine (Y694) phosphorylation, which was also observed in patient samples. The clinical course of the disease in patients with the N642H mutation was aggressive and fatal, clearly different from typical LGL leukemia with a relatively favorable outcome. This is the first time somatic STAT5 mutations are discovered in human cancer and further emphasizes the role of STAT family genes in the pathogenesis of LGL leukemia.
| S-EPMC3668487 | biostudies-literature
Project description:Background. T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a dismal prognosis. It represents 15% of pediatric ALL and has a threefold higher incidence among males. T-cell transformation is a multi-step process involving cooperating events leading to altered T-cell signaling, proliferation, differentiation and survival. Many recurrent alterations have been identified and help define molecular subgroups of T-ALL, however the full range of events involved in driving transformation remain to be defined. Results. Using an integrative approach combining genomic and transcriptomic data, we performed comprehensive molecular characterization of 30 pediatric T-ALLs. We identified common T-ALL targets and confirmed the overall poor outcome of early immature cases. We also showed that deletion of the CDKN2A locus is associated with lower risk of relapse. In addition, we identified novel T-ALL drivers including a member of the spliceosome machinery U2AF1 as well as novel X-linked tumor suppressors MED12 and USP9X, that had never been associated to T-ALL before. Interestingly, almost 60% of these events were found in early immature cases which represented only 35% of the cohort. Functional validations further demonstrated the putative role of these novel T-ALL genes in driving transformation by demonstrating the aberrant splicing provoked by U2AF1 p.R35L and the protective effect against apoptosis of MED12 and USP9X repression. Conclusions. This study highlights the underlying genomic complexity of pediatric T-ALL, and the need for larger integrative studies to decipher the mechanisms that contribute to its various subtypes and provide opportunities to refine patient stratification and treatment.
2016-03-02 | GSE78783 | GEO
Project description:Background. T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a dismal prognosis. It represents 15% of pediatric ALL and has a threefold higher incidence among males. T-cell transformation is a multi-step process involving cooperating events leading to altered T-cell signaling, proliferation, differentiation and survival. Many recurrent alterations have been identified and help define molecular subgroups of T-ALL, however the full range of events involved in driving transformation remain to be defined. Results. Using an integrative approach combining genomic and transcriptomic data, we performed comprehensive molecular characterization of 30 pediatric T-ALLs. We identified common T-ALL targets and confirmed the overall poor outcome of early immature cases. We also showed that deletion of the CDKN2A locus is associated with lower risk of relapse. In addition, we identified novel T-ALL drivers including a member of the spliceosome machinery U2AF1 as well as novel X-linked tumor suppressors MED12 and USP9X, that had never been associated to T-ALL before. Interestingly, almost 60% of these events were found in early immature cases which represented only 35% of the cohort. Functional validations further demonstrated the putative role of these novel T-ALL genes in driving transformation by demonstrating the aberrant splicing provoked by U2AF1 p.R35L and the protective effect against apoptosis of MED12 and USP9X repression. Conclusions. This study highlights the underlying genomic complexity of pediatric T-ALL, and the need for larger integrative studies to decipher the mechanisms that contribute to its various subtypes and provide opportunities to refine patient stratification and treatment.
2016-03-02 | GSE78785 | GEO
Project description:Activating signaling mutations are common in acute leukemia with KMT2A (previously MLL) rearrangements. Herein, we show that co-expression of FLT3-N676K and KMT2A-MLLT3 in human CD34+ cord blood cells primarily cause acute myeloid leukemia (AML) and rarely acute lymphoblastic leukemia (ALL) in immunodeficient mice. By contrast, expression of KMT2A-MLLT3 alone cause ALL, double-positive leukemia (DPL, expressing both CD33 and CD19), or bilineal leukemia (BLL, comprised of distinct myeloid and lymphoid leukemia cells), and rarely AML. Further, AML could only be serially propagated with maintained immunophenotype in secondary recipients when cells co-expressed KMT2A-MLLT3 and FLT3-N676K. Consistent with the idea that activated signaling would allow myeloid cells to engraft and maintain their self-renewal capacity, in a secondary recipient, a de novo KRAS-G13D was identified in myeloid cells previously expressing only KMT2A-MLLT3. Gene expression profiling revealed that KMT2A-MLLT3 DPL had a highly similar gene expression profile to ALL, with both expressing key lymphoid transcription factors and ALL cell surface markers, in line with the DPL cells being ALL cells with aberrant expression of CD33. Taken together, our results highlight the need for constitutive active signaling mutations for driving myeloid leukemia in a human xenograft model of KMT2A-R acute leukemia.
2019-04-05 | GSE127492 | GEO