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1.
Blood ; 141(5): 534-549, 2023 02 02.
Article in English | MEDLINE | ID: mdl-36322930

ABSTRACT

Germ line DDX41 variants have been implicated in late-onset myeloid neoplasms (MNs). Despite an increasing number of publications, many important features of DDX41-mutated MNs remain to be elucidated. Here we performed a comprehensive characterization of DDX41-mutated MNs, enrolling a total of 346 patients with DDX41 pathogenic/likely-pathogenic (P/LP) germ line variants and/or somatic mutations from 9082 MN patients, together with 525 first-degree relatives of DDX41-mutated and wild-type (WT) patients. P/LP DDX41 germ line variants explained ∼80% of known germ line predisposition to MNs in adults. These risk variants were 10-fold more enriched in Japanese MN cases (n = 4461) compared with the general population of Japan (n = 20 238). This enrichment of DDX41 risk alleles was much more prominent in male than female (20.7 vs 5.0). P/LP DDX41 variants conferred a large risk of developing MNs, which was negligible until 40 years of age but rapidly increased to 49% by 90 years of age. Patients with myelodysplastic syndromes (MDS) along with a DDX41-mutation rapidly progressed to acute myeloid leukemia (AML), which was however, confined to those having truncating variants. Comutation patterns at diagnosis and at progression to AML were substantially different between DDX41-mutated and WT cases, in which none of the comutations affected clinical outcomes. Even TP53 mutations made no exceptions and their dismal effect, including multihit allelic status, on survival was almost completely mitigated by the presence of DDX41 mutations. Finally, outcomes were not affected by the conventional risk stratifications including the revised/molecular International Prognostic Scoring System. Our findings establish that MDS with DDX41-mutation defines a unique subtype of MNs that is distinct from other MNs.


Subject(s)
DEAD-box RNA Helicases , Leukemia, Myeloid, Acute , Myelodysplastic Syndromes , Myeloproliferative Disorders , Adult , Aged, 80 and over , Female , Humans , Male , DEAD-box RNA Helicases/genetics , Germ Cells , Leukemia, Myeloid, Acute/genetics , Mutation , Myelodysplastic Syndromes/genetics , Myeloproliferative Disorders/genetics
2.
Blood ; 138(19): 1885-1895, 2021 11 11.
Article in English | MEDLINE | ID: mdl-34075412

ABSTRACT

Although genomic alterations drive the pathogenesis of acute myeloid leukemia (AML), traditional classifications are largely based on morphology, and prototypic genetic founder lesions define only a small proportion of AML patients. The historical subdivision of primary/de novo AML and secondary AML has shown to variably correlate with genetic patterns. The combinatorial complexity and heterogeneity of AML genomic architecture may have thus far precluded genomic-based subclassification to identify distinct molecularly defined subtypes more reflective of shared pathogenesis. We integrated cytogenetic and gene sequencing data from a multicenter cohort of 6788 AML patients that were analyzed using standard and machine learning methods to generate a novel AML molecular subclassification with biologic correlates corresponding to underlying pathogenesis. Standard supervised analyses resulted in modest cross-validation accuracy when attempting to use molecular patterns to predict traditional pathomorphologic AML classifications. We performed unsupervised analysis by applying the Bayesian latent class method that identified 4 unique genomic clusters of distinct prognoses. Invariant genomic features driving each cluster were extracted and resulted in 97% cross-validation accuracy when used for genomic subclassification. Subclasses of AML defined by molecular signatures overlapped current pathomorphologic and clinically defined AML subtypes. We internally and externally validated our results and share an open-access molecular classification scheme for AML patients. Although the heterogeneity inherent in the genomic changes across nearly 7000 AML patients was too vast for traditional prediction methods, machine learning methods allowed for the definition of novel genomic AML subclasses, indicating that traditional pathomorphologic definitions may be less reflective of overlapping pathogenesis.


Subject(s)
Leukemia, Myeloid, Acute/genetics , Machine Learning , Bayes Theorem , Cytogenetics , Gene Expression Regulation, Leukemic , Genomics , Humans , Leukemia, Myeloid, Acute/classification , Leukemia, Myeloid, Acute/diagnosis , Mutation , Neoplasms, Second Primary/classification , Neoplasms, Second Primary/diagnosis , Neoplasms, Second Primary/genetics , Translocation, Genetic
3.
Rinsho Ketsueki ; 64(5): 355-368, 2023.
Article in Japanese | MEDLINE | ID: mdl-37271526

ABSTRACT

The prognosis for patients with myelodysplastic syndromes (MDS) was classified into several groups by the International Prognostic Scoring System for Myelodysplastic Syndromes (IPSS) or its revised version, based on chromosome aberrations, blast counts, and hematological abnormalities. Although genetic mutations, including TP53, DDX41, and SF3B1, had prognostic importance, the coexistence of these genetic abnormalities makes systematic risk stratification extremely hard. Recently, an international working group reported a large study of 3,000 patients with MDS, which proposed a novel IPSS using genetic mutations (IPSS-M). They have released an open-access web page ( https://mds-risk-model.com/ ) that considers missing values and is being used worldwide. By combining genomic profiling with hematological and cytogenetic parameters, IPSS-M is expected to improve the risk stratification of patients with MDS and be an essential tool for clinical decision-making, including treatment options.


Subject(s)
Myelodysplastic Syndromes , Humans , Prognosis , Myelodysplastic Syndromes/diagnosis , Myelodysplastic Syndromes/genetics , Myelodysplastic Syndromes/therapy , Chromosome Aberrations , Mutation , Cytogenetics
4.
Blood ; 136(20): 2249-2262, 2020 11 12.
Article in English | MEDLINE | ID: mdl-32961553

ABSTRACT

Morphologic interpretation is the standard in diagnosing myelodysplastic syndrome (MDS), but it has limitations, such as varying reliability in pathologic evaluation and lack of integration with genetic data. Somatic events shape morphologic features, but the complexity of morphologic and genetic changes makes clear associations challenging. This article interrogates novel clinical subtypes of MDS using a machine-learning technique devised to identify patterns of cooccurrence among morphologic features and genomic events. We sequenced 1079 MDS patients and analyzed bone marrow morphologic alterations and other clinical features. A total of 1929 somatic mutations were identified. Five distinct morphologic profiles with unique clinical characteristics were defined. Seventy-seven percent of higher-risk patients clustered in profile 1. All lower-risk (LR) patients clustered into the remaining 4 profiles: profile 2 was characterized by pancytopenia, profile 3 by monocytosis, profile 4 by elevated megakaryocytes, and profile 5 by erythroid dysplasia. These profiles could also separate patients with different prognoses. LR MDS patients were classified into 8 genetic signatures (eg, signature A had TET2 mutations, signature B had both TET2 and SRSF2 mutations, and signature G had SF3B1 mutations), demonstrating association with specific morphologic profiles. Six morphologic profiles/genetic signature associations were confirmed in a separate analysis of an independent cohort. Our study demonstrates that nonrandom or even pathognomonic relationships between morphology and genotype to define clinical features can be identified. This is the first comprehensive implementation of machine-learning algorithms to elucidate potential intrinsic interdependencies among genetic lesions, morphologies, and clinical prognostic in attributes of MDS.


Subject(s)
Machine Learning , Myelodysplastic Syndromes/genetics , Myelodysplastic Syndromes/pathology , Adult , Aged , Female , Genetic Association Studies , Humans , Male , Middle Aged , Mutation
5.
Nature ; 534(7607): 402-6, 2016 06 16.
Article in English | MEDLINE | ID: mdl-27281199

ABSTRACT

Successful treatment of many patients with advanced cancer using antibodies against programmed cell death 1 (PD-1; also known as PDCD1) and its ligand (PD-L1; also known as CD274) has highlighted the critical importance of PD-1/PD-L1-mediated immune escape in cancer development. However, the genetic basis for the immune escape has not been fully elucidated, with the exception of elevated PD-L1 expression by gene amplification and utilization of an ectopic promoter by translocation, as reported in Hodgkin and other B-cell lymphomas, as well as stomach adenocarcinoma. Here we show a unique genetic mechanism of immune escape caused by structural variations (SVs) commonly disrupting the 3' region of the PD-L1 gene. Widely affecting multiple common human cancer types, including adult T-cell leukaemia/lymphoma (27%), diffuse large B-cell lymphoma (8%), and stomach adenocarcinoma (2%), these SVs invariably lead to a marked elevation of aberrant PD-L1 transcripts that are stabilized by truncation of the 3'-untranslated region (UTR). Disruption of the Pd-l1 3'-UTR in mice enables immune evasion of EG7-OVA tumour cells with elevated Pd-l1 expression in vivo, which is effectively inhibited by Pd-1/Pd-l1 blockade, supporting the role of relevant SVs in clonal selection through immune evasion. Our findings not only unmask a novel regulatory mechanism of PD-L1 expression, but also suggest that PD-L1 3'-UTR disruption could serve as a genetic marker to identify cancers that actively evade anti-tumour immunity through PD-L1 overexpression.


Subject(s)
3' Untranslated Regions/genetics , Gene Expression Regulation, Neoplastic , Neoplasms/genetics , Programmed Cell Death 1 Receptor/genetics , Tumor Escape/genetics , Up-Regulation , Adenocarcinoma/genetics , Animals , Antibodies/pharmacology , Antibodies/therapeutic use , CRISPR-Cas Systems , Cell Line, Tumor , Clonal Selection, Antigen-Mediated , Female , Genetic Markers/genetics , Humans , Leukemia-Lymphoma, Adult T-Cell/genetics , Lymphoma, Large B-Cell, Diffuse/genetics , Mice , Neoplasms/pathology , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Programmed Cell Death 1 Receptor/biosynthesis , RNA Stability , RNA, Messenger/genetics , RNA, Messenger/metabolism , Stomach Neoplasms/genetics
6.
Blood ; 131(2): 215-225, 2018 01 11.
Article in English | MEDLINE | ID: mdl-29084771

ABSTRACT

Adult T-cell leukemia/lymphoma (ATL) is a heterogeneous group of peripheral T-cell malignancies characterized by human T-cell leukemia virus type-1 infection, whose genetic profile has recently been fully investigated. However, it is still poorly understood how these alterations affect clinical features and prognosis. We investigated the effects of genetic alterations commonly found in ATL on disease phenotypes and clinical outcomes, based on genotyping data obtained from 414 and 463 ATL patients using targeted-capture sequencing and single nucleotide polymorphism array karyotyping, respectively. Aggressive (acute/lymphoma) subtypes were associated with an increased burden of genetic and epigenetic alterations, higher frequencies of TP53 and IRF4 mutations, and many copy number alterations (CNAs), including PD-L1 amplifications and CDKN2A deletions, compared with indolent (chronic/smoldering) subtypes. By contrast, STAT3 mutations were more characteristic of indolent ATL. Higher numbers of somatic mutations and CNAs significantly correlated with worse survival. In a multivariate analysis incorporating both clinical factors and genetic alterations, the Japan Clinical Oncology Group prognostic index high-risk, older age, PRKCB mutations, and PD-L1 amplifications were independent poor prognostic factors in aggressive ATL. In indolent ATL, IRF4 mutations, PD-L1 amplifications, and CDKN2A deletions were significantly associated with shorter survival, although the chronic subtype with unfavorable clinical factors was only marginally significant. Thus, somatic alterations characterizing aggressive diseases predict worse prognosis in indolent ATL, among which PD-L1 amplifications are a strong genetic predictor in both aggressive and indolent ATL. ATL subtypes are further classified into molecularly distinct subsets with different prognosis. Genetic profiling might contribute to improved prognostication and management of ATL patients.


Subject(s)
Gene Expression Regulation, Leukemic , Leukemia-Lymphoma, Adult T-Cell/diagnosis , Leukemia-Lymphoma, Adult T-Cell/genetics , Mutation , Abnormal Karyotype , Aged , Epigenesis, Genetic , Female , Gene Dosage , Humans , Interferon Regulatory Factors/genetics , Male , Middle Aged , Models, Molecular , Polymorphism, Single Nucleotide , Prognosis , STAT3 Transcription Factor/genetics
8.
Br J Haematol ; 185(5): 935-939, 2019 06.
Article in English | MEDLINE | ID: mdl-30891747

ABSTRACT

Compound heterozygous germline mutations in CTC1 gene have been found in patients with atypical dyskeratosis congenita (DC), whereas heterozygous carriers are unaffected. Through screening of a large cohort of adult patients with acquired bone marrow failure syndromes, in addition to a DC case, we have also found extremely rare or novel heterozygous deleterious germline variants of CTC1 in patients with aplastic anaemia (AA; n = 5), paroxysmal nocturnal haemoglobinuria (PNH; n = 3) and myelodysplastic syndrome (MDS; n = 2). A compound heterozygous case of AA showed clonal evolution. Our results suggest that some of the inherited CTC1 variants may represent predisposition factors for acquired bone marrow failure.


Subject(s)
Bone Marrow Failure Disorders/genetics , Germ-Line Mutation , Telomere-Binding Proteins/genetics , Telomere/genetics , Adult , Aged , Aged, 80 and over , Bone Marrow Failure Disorders/metabolism , Bone Marrow Failure Disorders/pathology , Female , Humans , Male , Middle Aged , Telomere/metabolism , Telomere/pathology , Telomere-Binding Proteins/metabolism
9.
Blood ; 129(17): 2347-2358, 2017 04 27.
Article in English | MEDLINE | ID: mdl-28223278

ABSTRACT

Genetic alterations, including mutations and copy-number alterations, are central to the pathogenesis of myelodysplastic syndromes and related diseases (myelodysplasia), but their roles in allogeneic stem cell transplantation have not fully been studied in a large cohort of patients. We enrolled 797 patients who had been diagnosed with myelodysplasia at initial presentation and received transplantation via the Japan Marrow Donor Program. Targeted-capture sequencing was performed to identify mutations in 69 genes, together with copy-number alterations, whose effects on transplantation outcomes were investigated. We identified 1776 mutations and 927 abnormal copy segments among 617 patients (77.4%). In multivariate modeling using Cox proportional-hazards regression, genetic factors explained 30% of the total hazards for overall survival; clinical characteristics accounted for 70% of risk. TP53 and RAS-pathway mutations, together with complex karyotype (CK) as detected by conventional cytogenetics and/or sequencing-based analysis, negatively affected posttransplant survival independently of clinical factors. Regardless of disease subtype, TP53-mutated patients with CK were characterized by unique genetic features and associated with an extremely poor survival with frequent early relapse, whereas outcomes were substantially better in TP53-mutated patients without CK. By contrast, the effects of RAS-pathway mutations depended on disease subtype and were confined to myelodysplastic/myeloproliferative neoplasms (MDS/MPNs). Our results suggest that TP53 and RAS-pathway mutations predicted a dismal prognosis, when associated with CK and MDS/MPNs, respectively. However, for patients with mutated TP53 or CK alone, long-term survival could be obtained with transplantation. Clinical sequencing provides vital information for accurate prognostication in transplantation.


Subject(s)
Chromosome Aberrations , Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute/genetics , Mutation , Myelodysplastic Syndromes/genetics , Tumor Suppressor Protein p53/genetics , ras Proteins/genetics , Adolescent , Adult , Aged , Child , Cohort Studies , DNA Copy Number Variations , Female , Hematopoietic Stem Cells , High-Throughput Nucleotide Sequencing , Humans , Leukemia, Myeloid, Acute/etiology , Leukemia, Myeloid, Acute/mortality , Leukemia, Myeloid, Acute/therapy , Male , Middle Aged , Myelodysplastic Syndromes/complications , Myelodysplastic Syndromes/mortality , Myelodysplastic Syndromes/therapy , Prognosis , Proportional Hazards Models , Recurrence , Risk , Transplantation, Homologous , Treatment Outcome , Tumor Suppressor Protein p53/metabolism , ras Proteins/metabolism
10.
Ann Hematol ; 98(1): 83-91, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30251205

ABSTRACT

We analyzed the clinical significance and genetic features of ASXL2 and ZBTB7A mutations, and the alternatively spliced isoform of the RUNX1-RUNX1T1 transcript, which is also called AML1-ETO9a (AE9a), in Japanese CBF-AML patients enrolled in the JALSG AML201 study. ASXL2 and ZBTB7A genes were sequenced using bone marrow samples of 41 AML patients with t(8;21) and 14 with inv(16). The relative expression levels of AE9a were quantified using the real-time PCR assay in 23 AML patients with t(8;21). We identified ASXL2 (34.1%) and ZBTB7A (9.8%) mutations in only AML patients with t(8;21). ASXL2-mutated patients had a significantly higher WBC count at diagnosis (P = 0.04) and a lower frequency of sex chromosome loss than wild-type patients (33 vs. 76%, respectively, P = 0.01). KIT mutations were the most frequently accompanied with both ASXL2 (36%) and ZBTB7A (75%) mutations. Neither ASXL2 nor ZBTB7A mutations had an impact on overall or event-free survival. Patients harboring cohesin complex gene mutations expressed significantly higher levels of AE9a than unmutated patients (P = 0.03). In conclusion, ASXL2 and ZBTB7A mutations were frequently identified in Japanese AML patients with t(8;21), but not in those with inv(16). Further analysis is required to clarify the detailed biological mechanism of AE9a regulation of the cohesin complex.


Subject(s)
Chromosomes, Human, Pair 21/genetics , Chromosomes, Human, Pair 8/genetics , Core Binding Factor Alpha 2 Subunit , DNA-Binding Proteins , Gene Expression Regulation, Leukemic , Leukemia, Myeloid, Acute , Oncogene Proteins, Fusion , RUNX1 Translocation Partner 1 Protein , Repressor Proteins , Transcription Factors , Translocation, Genetic , Adolescent , Adult , Aged , Child , Core Binding Factor Alpha 2 Subunit/biosynthesis , Core Binding Factor Alpha 2 Subunit/genetics , DNA-Binding Proteins/biosynthesis , DNA-Binding Proteins/genetics , Disease-Free Survival , Female , Humans , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/mortality , Male , Middle Aged , Oncogene Proteins, Fusion/biosynthesis , Oncogene Proteins, Fusion/genetics , RUNX1 Translocation Partner 1 Protein/biosynthesis , RUNX1 Translocation Partner 1 Protein/genetics , Repressor Proteins/biosynthesis , Repressor Proteins/genetics , Survival Rate , Transcription Factors/biosynthesis , Transcription Factors/genetics
11.
PLoS Genet ; 12(2): e1005778, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26890883

ABSTRACT

Understanding intratumor heterogeneity is clinically important because it could cause therapeutic failure by fostering evolutionary adaptation. To this end, we profiled the genome and epigenome in multiple regions within each of nine colorectal tumors. Extensive intertumor heterogeneity is observed, from which we inferred the evolutionary history of the tumors. First, clonally shared alterations appeared, in which C>T transitions at CpG site and CpG island hypermethylation were relatively enriched. Correlation between mutation counts and patients' ages suggests that the early-acquired alterations resulted from aging. In the late phase, a parental clone was branched into numerous subclones. Known driver alterations were observed frequently in the early-acquired alterations, but rarely in the late-acquired alterations. Consistently, our computational simulation of the branching evolution suggests that extensive intratumor heterogeneity could be generated by neutral evolution. Collectively, we propose a new model of colorectal cancer evolution, which is useful for understanding and confronting this heterogeneous disease.


Subject(s)
Biological Evolution , Colorectal Neoplasms/genetics , Epigenesis, Genetic , Mutation , Aged , Aged, 80 and over , Aging/genetics , Class I Phosphatidylinositol 3-Kinases , Colorectal Neoplasms/pathology , CpG Islands , DNA Methylation , Exome , Female , Founder Effect , Humans , Male , Middle Aged , Models, Biological , Phosphatidylinositol 3-Kinases/genetics , Polymorphism, Single Nucleotide
12.
N Engl J Med ; 373(1): 35-47, 2015 Jul 02.
Article in English | MEDLINE | ID: mdl-26132940

ABSTRACT

BACKGROUND: In patients with acquired aplastic anemia, destruction of hematopoietic cells by the immune system leads to pancytopenia. Patients have a response to immunosuppressive therapy, but myelodysplastic syndromes and acute myeloid leukemia develop in about 15% of the patients, usually many months to years after the diagnosis of aplastic anemia. METHODS: We performed next-generation sequencing and array-based karyotyping using 668 blood samples obtained from 439 patients with aplastic anemia. We analyzed serial samples obtained from 82 patients. RESULTS: Somatic mutations in myeloid cancer candidate genes were present in one third of the patients, in a limited number of genes and at low initial variant allele frequency. Clonal hematopoiesis was detected in 47% of the patients, most frequently as acquired mutations. The prevalence of the mutations increased with age, and mutations had an age-related signature. DNMT3A-mutated and ASXL1-mutated clones tended to increase in size over time; the size of BCOR- and BCORL1-mutated and PIGA-mutated clones decreased or remained stable. Mutations in PIGA and BCOR and BCORL1 correlated with a better response to immunosuppressive therapy and longer and a higher rate of overall and progression-free survival; mutations in a subgroup of genes that included DNMT3A and ASXL1 were associated with worse outcomes. However, clonal dynamics were highly variable and might not necessarily have predicted the response to therapy and long-term survival among individual patients. CONCLUSIONS: Clonal hematopoiesis was prevalent in aplastic anemia. Some mutations were related to clinical outcomes. A highly biased set of mutations is evidence of Darwinian selection in the failed bone marrow environment. The pattern of somatic clones in individual patients over time was variable and frequently unpredictable. (Funded by Grant-in-Aid for Scientific Research and others.).


Subject(s)
Anemia, Aplastic/genetics , Hematopoiesis/genetics , Mutation , Age Factors , Aged , Anemia, Aplastic/blood , Anemia, Aplastic/mortality , Clone Cells , Female , Humans , Karyotyping , Leukemia, Myeloid, Acute/genetics , Male , Middle Aged , Myelodysplastic Syndromes/genetics , Polymorphism, Single Nucleotide , Risk Factors , Sequence Analysis, DNA
13.
Blood ; 127(5): 596-604, 2016 Feb 04.
Article in English | MEDLINE | ID: mdl-26574607

ABSTRACT

Adult T-cell leukemia/lymphoma (ATLL) is a distinct form of peripheral T-cell lymphoma with poor prognosis, which is caused by the human T-lymphotropic virus type 1 (HTLV-1). In contrast to the unequivocal importance of HTLV-1 infection in the pathogenesis of ATLL, the role of acquired mutations in HTLV-1 infected T cells has not been fully elucidated, with a handful of genes known to be recurrently mutated. In this study, we identified unique RHOA mutations in ATLL through whole genome sequencing of an index case, followed by deep sequencing of 203 ATLL samples. RHOA mutations showed distinct distribution and function from those found in other cancers. Involving 15% (30/203) of ATLL cases, RHOA mutations were widely distributed across the entire coding sequence but almost invariably located at the guanosine triphosphate (GTP)-binding pocket, with Cys16Arg being most frequently observed. Unexpectedly, depending on mutation types and positions, these RHOA mutants showed different or even opposite functional consequences in terms of GTP/guanosine diphosphate (GDP)-binding kinetics, regulation of actin fibers, and transcriptional activation. The Gly17Val mutant did not bind GTP/GDP and act as a dominant negative molecule, whereas other mutants (Cys16Arg and Ala161Pro) showed fast GTP/GDP cycling with enhanced transcriptional activation. These findings suggest that both loss- and gain-of-RHOA functions could be involved in ATLL leukemogenesis. In summary, our study not only provides a novel insight into the molecular pathogenesis of ATLL but also highlights a unique role of variegation of heterologous RHOA mutations in human cancers.


Subject(s)
Leukemia-Lymphoma, Adult T-Cell/genetics , Mutation , rhoA GTP-Binding Protein/genetics , Adult , Amino Acid Sequence , Binding Sites , DNA Mutational Analysis , Guanosine Diphosphate/metabolism , Guanosine Triphosphate/metabolism , High-Throughput Nucleotide Sequencing , Humans , Leukemia-Lymphoma, Adult T-Cell/metabolism , Leukemia-Lymphoma, Adult T-Cell/pathology , Models, Molecular , Molecular Sequence Data , Protein Structure, Tertiary , rhoA GTP-Binding Protein/chemistry , rhoA GTP-Binding Protein/metabolism
14.
Blood ; 126(22): 2491-501, 2015 Nov 26.
Article in English | MEDLINE | ID: mdl-26438511

ABSTRACT

Acute myeloid leukemia (AML) with an FLT3 internal tandem duplication (FLT3-ITD) mutation is an aggressive hematologic malignancy with a grave prognosis. To identify the mutational spectrum associated with relapse, whole-exome sequencing was performed on 13 matched diagnosis, relapse, and remission trios followed by targeted sequencing of 299 genes in 67 FLT3-ITD patients. The FLT3-ITD genome has an average of 13 mutations per sample, similar to other AML subtypes, which is a low mutation rate compared with that in solid tumors. Recurrent mutations occur in genes related to DNA methylation, chromatin, histone methylation, myeloid transcription factors, signaling, adhesion, cohesin complex, and the spliceosome. Their pattern of mutual exclusivity and cooperation among mutated genes suggests that these genes have a strong biological relationship. In addition, we identified mutations in previously unappreciated genes such as MLL3, NSD1, FAT1, FAT4, and IDH3B. Mutations in 9 genes were observed in the relapse-specific phase. DNMT3A mutations are the most stable mutations, and this DNMT3A-transformed clone can be present even in morphologic complete remissions. Of note, all AML matched trio samples shared at least 1 genomic alteration at diagnosis and relapse, suggesting common ancestral clones. Two types of clonal evolution occur at relapse: either the founder clone recurs or a subclone of the founder clone escapes from induction chemotherapy and expands at relapse by acquiring new mutations. Relapse-specific mutations displayed an increase in transversions. Functional assays demonstrated that both MLL3 and FAT1 exert tumor-suppressor activity in the FLT3-ITD subtype. An inhibitor of XPO1 synergized with standard AML induction chemotherapy to inhibit FLT3-ITD growth. This study clearly shows that FLT3-ITD AML requires additional driver genetic alterations in addition to FLT3-ITD alone.


Subject(s)
Exome , Leukemia, Myeloid, Acute , Mutation , fms-Like Tyrosine Kinase 3/genetics , Chromatin/genetics , Chromatin/metabolism , DNA Methylation/genetics , Female , Humans , Induction Chemotherapy , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/mortality , Male , Recurrence , Retrospective Studies
15.
Haematologica ; 102(6): 1028-1034, 2017 06.
Article in English | MEDLINE | ID: mdl-28255022

ABSTRACT

Myelodysplastic syndromes are typically diseases of older adults. Patients in whom the onset is early may have distinct molecular and clinical features or reflect a demographic continuum. The identification of differences between "early onset" patients and those diagnosed at a traditional age has the potential to advance understanding of the pathogenesis of myelodysplasia and may lead to formation of distinct morphological subcategories. We studied a cohort of 634 patients with various subcategories of myelodysplastic syndrome and secondary acute myeloid leukemia, stratifying them based on age at presentation and clinical parameters. We then characterized molecular abnormalities detected by next-generation deep sequencing of 60 genes that are commonly mutated in myeloid malignancies. The number of mutations increased linearly with age and on average, patients >50 years of age had more mutations. TET2, SRSF2, and DNMT3A were more commonly mutated in patients >50 years old compared to patients ≤50 years old. In general, patients >50 years of age also had more mutations in spliceosomal, epigenetic modifier, and RAS gene families. Although there are age-related differences in molecular features among patients with myelodysplasia, most notably in the incidence of SRSF2 mutations, our results suggest that patients ≤50 years old belong to a disease continuum with a distinct pattern of early onset ancestral events.


Subject(s)
Age of Onset , Mutation , Myelodysplastic Syndromes/genetics , Adult , Age Factors , Aged , Aged, 80 and over , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Methyltransferase 3A , DNA Mutational Analysis , DNA-Binding Proteins/genetics , Dioxygenases , Female , High-Throughput Nucleotide Sequencing , Humans , Male , Middle Aged , Proto-Oncogene Proteins/genetics , Serine-Arginine Splicing Factors/genetics , Young Adult
16.
Nature ; 478(7367): 64-9, 2011 Sep 11.
Article in English | MEDLINE | ID: mdl-21909114

ABSTRACT

Myelodysplastic syndromes and related disorders (myelodysplasia) are a heterogeneous group of myeloid neoplasms showing deregulated blood cell production with evidence of myeloid dysplasia and a predisposition to acute myeloid leukaemia, whose pathogenesis is only incompletely understood. Here we report whole-exome sequencing of 29 myelodysplasia specimens, which unexpectedly revealed novel pathway mutations involving multiple components of the RNA splicing machinery, including U2AF35, ZRSR2, SRSF2 and SF3B1. In a large series analysis, these splicing pathway mutations were frequent (∼45 to ∼85%) in, and highly specific to, myeloid neoplasms showing features of myelodysplasia. Conspicuously, most of the mutations, which occurred in a mutually exclusive manner, affected genes involved in the 3'-splice site recognition during pre-mRNA processing, inducing abnormal RNA splicing and compromised haematopoiesis. Our results provide the first evidence indicating that genetic alterations of the major splicing components could be involved in human pathogenesis, also implicating a novel therapeutic possibility for myelodysplasia.


Subject(s)
Mutation/genetics , Myelodysplastic Syndromes/genetics , RNA Splicing/genetics , Alternative Splicing/genetics , Exome/genetics , Hematopoiesis/genetics , Humans , Nuclear Proteins/genetics , Polymorphism, Single Nucleotide/genetics , RNA Splice Sites/genetics , Ribonucleoproteins/genetics , Spliceosomes/genetics , Splicing Factor U2AF
17.
Rinsho Ketsueki ; 58(7): 776-786, 2017.
Article in Japanese | MEDLINE | ID: mdl-28781274

ABSTRACT

Targeted and unbiased next-generation sequencing (NGS) has contributed to a better understanding of the molecular pathogenesis of myeloid neoplasms, including MDS. Discovery efforts have identified novel classes of mutated genes, while deep NGS approaches have yielded a better appreciation of clonal hierarchy, intercase variability, and intratumor heterogeneity. However, comprehensive analyses of sequences of more than 100 genes in large cohorts are rare. We determined the biological and prognostic significance of genetic aberrations in MDS by summarizing recent reports. In one major report, 944 patients with various MDS subtypes were screened for known or putative mutations or deletions in 104 genes, using targeted deep sequencing and array-based genomic hybridization. Of the 944 patients, 845 (89.5%) harbored at least one mutation (median, 3 per patient; range, 0-12). In total, 47 genes were significantly mutated, with TET2, SF3B1, ASXL1, SRSF2, DNMT3A, and RUNX1 mutated in >10% of the patients. Many mutations were associated with higher risk groups and/or blast elevation. Survival was investigated in 875 patients. By univariate analysis, 25 of the 47 genes affected survival (P<0.05). The status of 14 genes combined with conventional factors revealed a novel prognostic model "Model-1", separating the patients into four risk groups "low", "intermediate", "high", and "very high" with 3-year survival rates of 95.2, 69.3, 32.8, and 5.3%, respectively (P<0.001). Subsequently, a "gene-only model" (Model-2), constructed on the basis of 14 genes, also yielded four significant risk groups (P<0.001). Both models were reproducible in the validation cohort (n = 175 patients; P<0.001 each). Similar analysis in another large cohort can reproduce the results, which suggests that profiling of genetic alterations is useful as a clinical tool to improve the prediction of prognosis.


Subject(s)
Myelodysplastic Syndromes/genetics , Aged , Female , Gene Deletion , High-Throughput Nucleotide Sequencing , Humans , Male , Mutation , Myelodysplastic Syndromes/diagnosis , Prognosis
18.
Br J Haematol ; 175(3): 476-489, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27470916

ABSTRACT

Acute myeloid leukaemia (AML) is a molecularly and clinically heterogeneous disease. Targeted sequencing efforts have identified several mutations with diagnostic and prognostic values in KIT, NPM1, CEBPA and FLT3 in both adult and paediatric AML. In addition, massively parallel sequencing enabled the discovery of recurrent mutations (i.e. IDH1/2 and DNMT3A) in adult AML. In this study, whole-exome sequencing (WES) of 22 paediatric AML patients revealed mutations in components of the cohesin complex (RAD21 and SMC3), BCORL1 and ASXL2 in addition to previously known gene mutations. We also revealed intratumoural heterogeneities in many patients, implicating multiple clonal evolution events in the development of AML. Furthermore, targeted deep sequencing in 182 paediatric AML patients identified three major categories of recurrently mutated genes: cohesion complex genes [STAG2, RAD21 and SMC3 in 17 patients (8·3%)], epigenetic regulators [ASXL1/ASXL2 in 17 patients (8·3%), BCOR/BCORL1 in 7 patients (3·4%)] and signalling molecules. We also performed WES in four patients with relapsed AML. Relapsed AML evolved from one of the subclones at the initial phase and was accompanied by many additional mutations, including common driver mutations that were absent or existed only with lower allele frequency in the diagnostic samples, indicating a multistep process causing leukaemia recurrence.


Subject(s)
Clonal Evolution/genetics , Exome , High-Throughput Nucleotide Sequencing , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Mutation , Child , DNA Mutational Analysis , Disease Progression , Epigenesis, Genetic , Female , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Leukemia, Myeloid, Acute/mortality , Male , Nucleophosmin , Prognosis , Recurrence
19.
Bioinformatics ; 31(1): 116-8, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25192740

ABSTRACT

SUMMARY: Somatic internal tandem duplications (ITDs) are known to play important roles in cancer pathogenesis. Although recent advances in high-throughput sequencing technologies have enabled genome-wide detection of various types of genomic mutations, including single nucleotide variants, indels and structural variations, only a few studies have focused on ITDs. We have developed an analytical tool called 'Genomon ITDetector' for genome-wide detection of somatic ITDs. After evaluating the sensitivity and precision of the proposed approach using synthetic data, we have demonstrated that it can successfully detect not only common ITDs involving FLT3, but also a number of ITDs affecting other putative driver genes in acute myeloid leukemia exome sequencing data. Availability and implementaion: Genomon ITDetector is freely available at https://github.com/ken0-1n/Genomon-ITDetector.


Subject(s)
Computational Biology/methods , DNA Mutational Analysis/methods , Exome/genetics , High-Throughput Nucleotide Sequencing/methods , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Mutation/genetics , Tandem Repeat Sequences/genetics , fms-Like Tyrosine Kinase 3/genetics , Humans
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