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1.
Nat Commun ; 9(1): 3962, 2018 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-30262806

RESUMO

To evaluate the potential of an integrated clinical test to detect diverse classes of somatic and germline mutations relevant to pediatric oncology, we performed three-platform whole-genome (WGS), whole exome (WES) and transcriptome (RNA-Seq) sequencing of tumors and normal tissue from 78 pediatric cancer patients in a CLIA-certified, CAP-accredited laboratory. Our analysis pipeline achieves high accuracy by cross-validating variants between sequencing types, thereby removing the need for confirmatory testing, and facilitates comprehensive reporting in a clinically-relevant timeframe. Three-platform sequencing has a positive predictive value of 97-99, 99, and 91% for somatic SNVs, indels and structural variations, respectively, based on independent experimental verification of 15,225 variants. We report 240 pathogenic variants across all cases, including 84 of 86 known from previous diagnostic testing (98% sensitivity). Combined WES and RNA-Seq, the current standard for precision oncology, achieved only 78% sensitivity. These results emphasize the critical need for incorporating WGS in pediatric oncology testing.


Assuntos
Exoma/genética , Genoma Humano , Genômica , Neoplasias/genética , Análise de Sequência de DNA , Transcriptoma/genética , Criança , Variação Genética , Humanos
2.
J Clin Oncol ; 36(20): 2078-2087, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29847298

RESUMO

Purpose Childhood cancer survivors are at increased risk of subsequent neoplasms (SNs), but the germline genetic contribution is largely unknown. We assessed the contribution of pathogenic/likely pathogenic (P/LP) mutations in cancer predisposition genes to their SN risk. Patients and Methods Whole-genome sequencing (30-fold) was performed on samples from childhood cancer survivors who were ≥ 5 years since initial cancer diagnosis and participants in the St Jude Lifetime Cohort Study, a retrospective hospital-based study with prospective clinical follow-up. Germline mutations in 60 genes known to be associated with autosomal dominant cancer predisposition syndromes with moderate to high penetrance were classified by their pathogenicity according to the American College of Medical Genetics and Genomics guidelines. Relative rates (RRs) and 95% CIs of SN occurrence by mutation status were estimated using multivariable piecewise exponential regression stratified by radiation exposure. Results Participants were 3,006 survivors (53% male; median age, 35.8 years [range, 7.1 to 69.8 years]; 56% received radiotherapy), 1,120 SNs were diagnosed among 439 survivors (14.6%), and 175 P/LP mutations were identified in 5.8% (95% CI, 5.0% to 6.7%) of survivors. Mutations were associated with significantly increased rates of breast cancer (RR, 13.9; 95% CI, 6.0 to 32.2) and sarcoma (RR, 10.6; 95% CI, 4.3 to 26.3) among irradiated survivors and with increased rates of developing any SN (RR, 4.7; 95% CI, 2.4 to 9.3), breast cancer (RR, 7.7; 95% CI, 2.4 to 24.4), nonmelanoma skin cancer (RR, 11.0; 95% CI, 2.9 to 41.4), and two or more histologically distinct SNs (RR, 18.6; 95% CI, 3.5 to 99.3) among nonirradiated survivors. Conclusion The findings support referral of all survivors for genetic counseling for potential clinical genetic testing, which should be prioritized for nonirradiated survivors with any SN and for those with breast cancer or sarcoma in the field of prior irradiation.


Assuntos
Sobreviventes de Câncer/estatística & dados numéricos , Segunda Neoplasia Primária/genética , Neoplasias/genética , Adolescente , Adulto , Idoso , Criança , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Segunda Neoplasia Primária/epidemiologia , Estudos Retrospectivos , Risco , Estados Unidos/epidemiologia , Sequenciamento Completo do Genoma , Adulto Jovem
3.
Nat Genet ; 48(12): 1481-1489, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27776115

RESUMO

Chromosomal rearrangements deregulating hematopoietic transcription factors are common in acute lymphoblastic leukemia (ALL). Here we show that deregulation of the homeobox transcription factor gene DUX4 and the ETS transcription factor gene ERG is a hallmark of a subtype of B-progenitor ALL that comprises up to 7% of B-ALL. DUX4 rearrangement and overexpression was present in all cases and was accompanied by transcriptional deregulation of ERG, expression of a novel ERG isoform, ERGalt, and frequent ERG deletion. ERGalt uses a non-canonical first exon whose transcription was initiated by DUX4 binding. ERGalt retains the DNA-binding and transactivation domains of ERG, but it inhibits wild-type ERG transcriptional activity and is transforming. These results illustrate a unique paradigm of transcription factor deregulation in leukemia in which DUX4 deregulation results in loss of function of ERG, either by deletion or induced expression of an isoform that is a dominant-negative inhibitor of wild-type ERG function.


Assuntos
Transformação Celular Neoplásica/genética , Deleção de Genes , Regulação Neoplásica da Expressão Gênica , Rearranjo Gênico , Proteínas de Homeodomínio/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Adulto , Transformação Celular Neoplásica/patologia , Perfilação da Expressão Gênica , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Isoformas de Proteínas , Regulador Transcricional ERG/genética , Adulto Jovem
4.
Nat Genet ; 48(12): 1551-1556, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27798625

RESUMO

Acute myeloid leukemia (AML) comprises a heterogeneous group of leukemias frequently defined by recurrent cytogenetic abnormalities, including rearrangements involving the core-binding factor (CBF) transcriptional complex. To better understand the genomic landscape of CBF-AMLs, we analyzed both pediatric (n = 87) and adult (n = 78) samples, including cases with RUNX1-RUNX1T1 (n = 85) or CBFB-MYH11 (n = 80) rearrangements, by whole-genome or whole-exome sequencing. In addition to known mutations in the Ras pathway, we identified recurrent stabilizing mutations in CCND2, suggesting a previously unappreciated cooperating pathway in CBF-AML. Outside of signaling alterations, RUNX1-RUNX1T1 and CBFB-MYH11 AMLs demonstrated remarkably different spectra of cooperating mutations, as RUNX1-RUNX1T1 cases harbored recurrent mutations in DHX15 and ZBTB7A, as well as an enrichment of mutations in epigenetic regulators, including ASXL2 and the cohesin complex. This detailed analysis provides insights into the pathogenesis and development of CBF-AML, while highlighting dramatic differences in the landscapes of cooperating mutations for these related AML subtypes.


Assuntos
Biomarcadores Tumorais/genética , Fatores de Ligação ao Core/genética , Genômica/métodos , Leucemia Mieloide Aguda/genética , Mutação/genética , Proteínas de Fusão Oncogênica/genética , Adulto , Criança , Humanos
5.
N Engl J Med ; 373(24): 2336-2346, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26580448

RESUMO

BACKGROUND: The prevalence and spectrum of predisposing mutations among children and adolescents with cancer are largely unknown. Knowledge of such mutations may improve the understanding of tumorigenesis, direct patient care, and enable genetic counseling of patients and families. METHODS: In 1120 patients younger than 20 years of age, we sequenced the whole genomes (in 595 patients), whole exomes (in 456), or both (in 69). We analyzed the DNA sequences of 565 genes, including 60 that have been associated with autosomal dominant cancer-predisposition syndromes, for the presence of germline mutations. The pathogenicity of the mutations was determined by a panel of medical experts with the use of cancer-specific and locus-specific genetic databases, the medical literature, computational predictions, and second hits identified in the tumor genome. The same approach was used to analyze data from 966 persons who did not have known cancer in the 1000 Genomes Project, and a similar approach was used to analyze data from an autism study (from 515 persons with autism and 208 persons without autism). RESULTS: Mutations that were deemed to be pathogenic or probably pathogenic were identified in 95 patients with cancer (8.5%), as compared with 1.1% of the persons in the 1000 Genomes Project and 0.6% of the participants in the autism study. The most commonly mutated genes in the affected patients were TP53 (in 50 patients), APC (in 6), BRCA2 (in 6), NF1 (in 4), PMS2 (in 4), RB1 (in 3), and RUNX1 (in 3). A total of 18 additional patients had protein-truncating mutations in tumor-suppressor genes. Of the 58 patients with a predisposing mutation and available information on family history, 23 (40%) had a family history of cancer. CONCLUSIONS: Germline mutations in cancer-predisposing genes were identified in 8.5% of the children and adolescents with cancer. Family history did not predict the presence of an underlying predisposition syndrome in most patients. (Funded by the American Lebanese Syrian Associated Charities and the National Cancer Institute.).


Assuntos
Genes Neoplásicos , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Neoplasias/genética , Adolescente , Transtorno Autístico/genética , Criança , Feminino , Genes Dominantes , Genoma Humano , Humanos , Masculino , Programa de SEER , Análise de Sequência de DNA/métodos , Adulto Jovem
6.
Nat Genet ; 47(4): 330-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25730765

RESUMO

Infant acute lymphoblastic leukemia (ALL) with MLL rearrangements (MLL-R) represents a distinct leukemia with a poor prognosis. To define its mutational landscape, we performed whole-genome, exome, RNA and targeted DNA sequencing on 65 infants (47 MLL-R and 18 non-MLL-R cases) and 20 older children (MLL-R cases) with leukemia. Our data show that infant MLL-R ALL has one of the lowest frequencies of somatic mutations of any sequenced cancer, with the predominant leukemic clone carrying a mean of 1.3 non-silent mutations. Despite this paucity of mutations, we detected activating mutations in kinase-PI3K-RAS signaling pathway components in 47% of cases. Surprisingly, these mutations were often subclonal and were frequently lost at relapse. In contrast to infant cases, MLL-R leukemia in older children had more somatic mutations (mean of 6.5 mutations/case versus 1.3 mutations/case, P = 7.15 × 10(-5)) and had frequent mutations (45%) in epigenetic regulators, a category of genes that, with the exception of MLL, was rarely mutated in infant MLL-R ALL.


Assuntos
Mutação , Proteína de Leucina Linfoide-Mieloide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Desequilíbrio Alélico/genética , Estudos de Coortes , Análise Mutacional de DNA , Frequência do Gene , Histona-Lisina N-Metiltransferase , Humanos , Lactente , Proteínas de Fusão Oncogênica/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais/genética , Proteínas ras/genética , Proteínas ras/metabolismo
7.
Nat Commun ; 6: 6604, 2015 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-25790293

RESUMO

There is incomplete understanding of genetic heterogeneity and clonal evolution during cancer progression. Here we use deep whole-exome sequencing to describe the clonal architecture and evolution of 20 pediatric B-acute lymphoblastic leukaemias from diagnosis to relapse. We show that clonal diversity is comparable at diagnosis and relapse and clonal survival from diagnosis to relapse is not associated with mutation burden. Six pathways were frequently mutated, with NT5C2, CREBBP, WHSC1, TP53, USH2A, NRAS and IKZF1 mutations enriched at relapse. Half of the leukaemias had multiple subclonal mutations in a pathway or gene at diagnosis, but mostly with only one, usually minor clone, surviving therapy to acquire additional mutations and become the relapse founder clone. Relapse-specific mutations in NT5C2 were found in nine cases, with mutations in four cases being in descendants of the relapse founder clone. These results provide important insights into the genetic basis of treatment failure in ALL and have implications for the early detection of mutations driving relapse.


Assuntos
Evolução Clonal/genética , Recidiva Local de Neoplasia/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , 5'-Nucleotidase/genética , Proteína de Ligação a CREB/genética , Criança , Células Clonais , Variações do Número de Cópias de DNA , Progressão da Doença , Exoma , Proteínas da Matriz Extracelular/genética , Feminino , GTP Fosfo-Hidrolases/genética , Histona-Lisina N-Metiltransferase/genética , Humanos , Fator de Transcrição Ikaros/genética , Masculino , Proteínas de Membrana/genética , Mutação , Proteínas Repressoras/genética , Proteína Supressora de Tumor p53/genética
8.
Cancer Discov ; 4(11): 1342-53, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25223734

RESUMO

UNLABELLED: Ewing sarcoma is a primary bone tumor initiated by EWSR1-ETS gene fusions. To identify secondary genetic lesions that contribute to tumor progression, we performed whole-genome sequencing of 112 Ewing sarcoma samples and matched germline DNA. Overall, Ewing sarcoma tumors had relatively few single-nucleotide variants, indels, structural variants, and copy-number alterations. Apart from whole chromosome arm copy-number changes, the most common somatic mutations were detected in STAG2 (17%), CDKN2A (12%), TP53 (7%), EZH2, BCOR, and ZMYM3 (2.7% each). Strikingly, STAG2 mutations and CDKN2A deletions were mutually exclusive, as confirmed in Ewing sarcoma cell lines. In an expanded cohort of 299 patients with clinical data, we discovered that STAG2 and TP53 mutations are often concurrent and are associated with poor outcome. Finally, we detected subclonal STAG2 mutations in diagnostic tumors and expansion of STAG2-immunonegative cells in relapsed tumors as compared with matched diagnostic samples. SIGNIFICANCE: Whole-genome sequencing reveals that the somatic mutation rate in Ewing sarcoma is low. Tumors that harbor STAG2 and TP53 mutations have a particularly dismal prognosis with current treatments and require alternative therapies. Novel drugs that target epigenetic regulators may constitute viable therapeutic strategies in a subset of patients with mutations in chromatin modifiers.


Assuntos
Antígenos Nucleares/genética , Neoplasias Ósseas/genética , Sarcoma de Ewing/genética , Proteína Supressora de Tumor p53/genética , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Inibidor p16 de Quinase Dependente de Ciclina/genética , DNA de Neoplasias/genética , Genômica , Humanos , Mutação , Prognóstico , Análise de Sequência de DNA
9.
N Engl J Med ; 371(11): 1005-15, 2014 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-25207766

RESUMO

BACKGROUND: Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is characterized by a gene-expression profile similar to that of BCR-ABL1-positive ALL, alterations of lymphoid transcription factor genes, and a poor outcome. The frequency and spectrum of genetic alterations in Ph-like ALL and its responsiveness to tyrosine kinase inhibition are undefined, especially in adolescents and adults. METHODS: We performed genomic profiling of 1725 patients with precursor B-cell ALL and detailed genomic analysis of 154 patients with Ph-like ALL. We examined the functional effects of fusion proteins and the efficacy of tyrosine kinase inhibitors in mouse pre-B cells and xenografts of human Ph-like ALL. RESULTS: Ph-like ALL increased in frequency from 10% among children with standard-risk ALL to 27% among young adults with ALL and was associated with a poor outcome. Kinase-activating alterations were identified in 91% of patients with Ph-like ALL; rearrangements involving ABL1, ABL2, CRLF2, CSF1R, EPOR, JAK2, NTRK3, PDGFRB, PTK2B, TSLP, or TYK2 and sequence mutations involving FLT3, IL7R, or SH2B3 were most common. Expression of ABL1, ABL2, CSF1R, JAK2, and PDGFRB fusions resulted in cytokine-independent proliferation and activation of phosphorylated STAT5. Cell lines and human leukemic cells expressing ABL1, ABL2, CSF1R, and PDGFRB fusions were sensitive in vitro to dasatinib, EPOR and JAK2 rearrangements were sensitive to ruxolitinib, and the ETV6-NTRK3 fusion was sensitive to crizotinib. CONCLUSIONS: Ph-like ALL was found to be characterized by a range of genomic alterations that activate a limited number of signaling pathways, all of which may be amenable to inhibition with approved tyrosine kinase inhibitors. Trials identifying Ph-like ALL are needed to assess whether adding tyrosine kinase inhibitors to current therapy will improve the survival of patients with this type of leukemia. (Funded by the American Lebanese Syrian Associated Charities and others.).


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Inibidores de Proteínas Quinases/uso terapêutico , Adolescente , Adulto , Animais , Criança , Pré-Escolar , DNA de Neoplasias/análise , Feminino , Genoma Humano , Xenoenxertos , Humanos , Lactente , Masculino , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Cromossomo Filadélfia , Polimorfismo de Nucleotídeo Único , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/mortalidade , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Transdução de Sinais/genética , Análise de Sobrevida , Adulto Jovem
10.
Nat Genet ; 46(5): 444-450, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24705251

RESUMO

Pediatric high-grade glioma (HGG) is a devastating disease with a less than 20% survival rate 2 years after diagnosis. We analyzed 127 pediatric HGGs, including diffuse intrinsic pontine gliomas (DIPGs) and non-brainstem HGGs (NBS-HGGs), by whole-genome, whole-exome and/or transcriptome sequencing. We identified recurrent somatic mutations in ACVR1 exclusively in DIPGs (32%), in addition to previously reported frequent somatic mutations in histone H3 genes, TP53 and ATRX, in both DIPGs and NBS-HGGs. Structural variants generating fusion genes were found in 47% of DIPGs and NBS-HGGs, with recurrent fusions involving the neurotrophin receptor genes NTRK1, NTRK2 and NTRK3 in 40% of NBS-HGGs in infants. Mutations targeting receptor tyrosine kinase-RAS-PI3K signaling, histone modification or chromatin remodeling, and cell cycle regulation were found in 68%, 73% and 59% of pediatric HGGs, respectively, including in DIPGs and NBS-HGGs. This comprehensive analysis provides insights into the unique and shared pathways driving pediatric HGG within and outside the brainstem.


Assuntos
Receptores de Ativinas Tipo I/genética , Neoplasias do Tronco Encefálico/genética , Glioma/genética , Transdução de Sinais/genética , Animais , Criança , Estudos de Coortes , Biologia Computacional , Perfilação da Expressão Gênica , Fusão Gênica/genética , Humanos , Immunoblotting , Imuno-Histoquímica , Análise em Microsséries , Receptor trkA/genética , Receptor trkB/genética , Receptor trkC/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Estatísticas não Paramétricas , Peixe-Zebra
11.
Nature ; 506(7489): 451-5, 2014 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-24553141

RESUMO

Members of the nuclear factor-κB (NF-κB) family of transcriptional regulators are central mediators of the cellular inflammatory response. Although constitutive NF-κB signalling is present in most human tumours, mutations in pathway members are rare, complicating efforts to understand and block aberrant NF-κB activity in cancer. Here we show that more than two-thirds of supratentorial ependymomas contain oncogenic fusions between RELA, the principal effector of canonical NF-κB signalling, and an uncharacterized gene, C11orf95. In each case, C11orf95-RELA fusions resulted from chromothripsis involving chromosome 11q13.1. C11orf95-RELA fusion proteins translocated spontaneously to the nucleus to activate NF-κB target genes, and rapidly transformed neural stem cells--the cell of origin of ependymoma--to form these tumours in mice. Our data identify a highly recurrent genetic alteration of RELA in human cancer, and the C11orf95-RELA fusion protein as a potential therapeutic target in supratentorial ependymoma.


Assuntos
Transformação Celular Neoplásica , Ependimoma/genética , Ependimoma/metabolismo , NF-kappa B/metabolismo , Proteínas/metabolismo , Transdução de Sinais , Fator de Transcrição RelA/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Sequência de Bases , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular , Núcleo Celular/metabolismo , Transformação Celular Neoplásica/genética , Cromossomos Humanos Par 11/genética , Ependimoma/patologia , Feminino , Humanos , Camundongos , Modelos Genéticos , Dados de Sequência Molecular , NF-kappa B/genética , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteínas/genética , Fator de Transcrição RelA/genética , Fatores de Transcrição , Translocação Genética/genética , Proteínas de Sinalização YAP
12.
Nat Genet ; 45(6): 602-12, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23583981

RESUMO

The most common pediatric brain tumors are low-grade gliomas (LGGs). We used whole-genome sequencing to identify multiple new genetic alterations involving BRAF, RAF1, FGFR1, MYB, MYBL1 and genes with histone-related functions, including H3F3A and ATRX, in 39 LGGs and low-grade glioneuronal tumors (LGGNTs). Only a single non-silent somatic alteration was detected in 24 of 39 (62%) tumors. Intragenic duplications of the portion of FGFR1 encoding the tyrosine kinase domain (TKD) and rearrangements of MYB were recurrent and mutually exclusive in 53% of grade II diffuse LGGs. Transplantation of Trp53-null neonatal astrocytes expressing FGFR1 with the duplication involving the TKD into the brains of nude mice generated high-grade astrocytomas with short latency and 100% penetrance. FGFR1 with the duplication induced FGFR1 autophosphorylation and upregulation of the MAPK/ERK and PI3K pathways, which could be blocked by specific inhibitors. Focusing on the therapeutically challenging diffuse LGGs, our study of 151 tumors has discovered genetic alterations and potential therapeutic targets across the entire range of pediatric LGGs and LGGNTs.


Assuntos
Neoplasias Encefálicas/genética , Glioma/genética , Adolescente , Animais , Sequência de Bases , Neoplasias Encefálicas/patologia , Criança , Pré-Escolar , Feminino , Duplicação Gênica , Rearranjo Gênico , Genes myb , Estudo de Associação Genômica Ampla , Glioma/patologia , Humanos , Lactente , Masculino , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Mutação , Gradação de Tumores , Transplante de Neoplasias , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas B-raf , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Análise de Sequência de DNA , Transdução de Sinais , Transativadores/genética , Transcriptoma
13.
Nat Genet ; 45(3): 242-52, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23334668

RESUMO

The genetic basis of hypodiploid acute lymphoblastic leukemia (ALL), a subtype of ALL characterized by aneuploidy and poor outcome, is unknown. Genomic profiling of 124 hypodiploid ALL cases, including whole-genome and exome sequencing of 40 cases, identified two subtypes that differ in the severity of aneuploidy, transcriptional profiles and submicroscopic genetic alterations. Near-haploid ALL with 24-31 chromosomes harbor alterations targeting receptor tyrosine kinase signaling and Ras signaling (71%) and the lymphoid transcription factor gene IKZF3 (encoding AIOLOS; 13%). In contrast, low-hypodiploid ALL with 32-39 chromosomes are characterized by alterations in TP53 (91.2%) that are commonly present in nontumor cells, IKZF2 (encoding HELIOS; 53%) and RB1 (41%). Both near-haploid and low-hypodiploid leukemic cells show activation of Ras-signaling and phosphoinositide 3-kinase (PI3K)-signaling pathways and are sensitive to PI3K inhibitors, indicating that these drugs should be explored as a new therapeutic strategy for this aggressive form of leukemia.


Assuntos
Aneuploidia , Aberrações Cromossômicas , Mutação , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Animais , Sequência de Bases , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Haploidia , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/metabolismo , Camundongos , Dados de Sequência Molecular , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Transdução de Sinais , Transplante Heterólogo , Resultado do Tratamento , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
14.
Nature ; 488(7409): 43-8, 2012 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-22722829

RESUMO

Medulloblastoma is a malignant childhood brain tumour comprising four discrete subgroups. Here, to identify mutations that drive medulloblastoma, we sequenced the entire genomes of 37 tumours and matched normal blood. One-hundred and thirty-six genes harbouring somatic mutations in this discovery set were sequenced in an additional 56 medulloblastomas. Recurrent mutations were detected in 41 genes not yet implicated in medulloblastoma; several target distinct components of the epigenetic machinery in different disease subgroups, such as regulators of H3K27 and H3K4 trimethylation in subgroups 3 and 4 (for example, KDM6A and ZMYM3), and CTNNB1-associated chromatin re-modellers in WNT-subgroup tumours (for example, SMARCA4 and CREBBP). Modelling of mutations in mouse lower rhombic lip progenitors that generate WNT-subgroup tumours identified genes that maintain this cell lineage (DDX3X), as well as mutated genes that initiate (CDH1) or cooperate (PIK3CA) in tumorigenesis. These data provide important new insights into the pathogenesis of medulloblastoma subgroups and highlight targets for therapeutic development.


Assuntos
Neoplasias Cerebelares/classificação , Neoplasias Cerebelares/genética , Meduloblastoma/classificação , Meduloblastoma/genética , Mutação/genética , Animais , Antígenos CD , Proteína de Ligação a CREB/genética , Caderinas/genética , Proteínas Cdh1 , Proteínas de Ciclo Celular/deficiência , Proteínas de Ciclo Celular/genética , Linhagem da Célula , Neoplasias Cerebelares/patologia , Criança , Classe I de Fosfatidilinositol 3-Quinases , RNA Helicases DEAD-box/genética , Variações do Número de Cópias de DNA , DNA Helicases/genética , Análise Mutacional de DNA , Modelos Animais de Doenças , Genoma Humano/genética , Genômica , Proteínas Hedgehog/metabolismo , Histona Desmetilases/genética , Histonas/metabolismo , Humanos , Meduloblastoma/patologia , Metilação , Camundongos , Proteínas Nucleares/genética , Fosfatidilinositol 3-Quinases/genética , Fatores de Transcrição/genética , Proteínas Wnt/metabolismo , beta Catenina/genética
15.
J Neurochem ; 112(1): 227-37, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19845833

RESUMO

Recognizing the similarities between Huntington's disease (HD) pathophysiology and the neurotoxicology of various metals, we hypothesized that they may exhibit disease-toxicant interactions revealing cellular pathways underlying neurodegeneration. Here, we utilize metals and the STHdh mouse striatal cell line model of HD to perform a gene-environment interaction screen. We report that striatal cells expressing mutant Huntingtin exhibit elevated sensitivity to cadmium toxicity and resistance to manganese toxicity. This neuroprotective gene-environment interaction with manganese is highly specific, as it does not occur with iron, copper, zinc, cobalt, cadmium, lead, or nickel ions. Analysis of the Akt cell stress signaling pathway showed diminished activation with manganese exposure and elevated activation after cadmium exposure in the mutant cells. Direct examination of intracellular manganese levels found that mutant cells have a significant impairment in manganese accumulation. Furthermore, YAC128Q mice, a HD model, showed decreased total striatal manganese levels following manganese exposure relative to wild-type mice. Thus, this disease-toxicant interaction screen has revealed that expression of mutant Huntingtin results in heightened sensitivity to cadmium neurotoxicity and a selective impairment of manganese accumulation.


Assuntos
Doença de Huntington/genética , Doença de Huntington/prevenção & controle , Manganês/toxicidade , Animais , Bovinos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Proteína Huntingtina , Doença de Huntington/induzido quimicamente , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética
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