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1.
Cell ; 164(5): 1060-1072, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26919435

RESUMO

Primitive neuroectodermal tumors of the central nervous system (CNS-PNETs) are highly aggressive, poorly differentiated embryonal tumors occurring predominantly in young children but also affecting adolescents and adults. Herein, we demonstrate that a significant proportion of institutionally diagnosed CNS-PNETs display molecular profiles indistinguishable from those of various other well-defined CNS tumor entities, facilitating diagnosis and appropriate therapy for patients with these tumors. From the remaining fraction of CNS-PNETs, we identify four new CNS tumor entities, each associated with a recurrent genetic alteration and distinct histopathological and clinical features. These new molecular entities, designated "CNS neuroblastoma with FOXR2 activation (CNS NB-FOXR2)," "CNS Ewing sarcoma family tumor with CIC alteration (CNS EFT-CIC)," "CNS high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1)," and "CNS high-grade neuroepithelial tumor with BCOR alteration (CNS HGNET-BCOR)," will enable meaningful clinical trials and the development of therapeutic strategies for patients affected by poorly differentiated CNS tumors.


Assuntos
Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/patologia , Metilação de DNA , Tumores Neuroectodérmicos/genética , Tumores Neuroectodérmicos/patologia , Sequência de Aminoácidos , Neoplasias do Sistema Nervoso Central/classificação , Neoplasias do Sistema Nervoso Central/diagnóstico , Criança , Fatores de Transcrição Forkhead/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Dados de Sequência Molecular , Tumores Neuroectodérmicos/classificação , Tumores Neuroectodérmicos/diagnóstico , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/química , Proteínas Repressoras/genética , Transdução de Sinais , Transativadores , Proteínas Supressoras de Tumor/genética
2.
Nat Cancer ; 4(2): 240-256, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36759733

RESUMO

BRAFV600E mutation confers a poor prognosis in metastatic colorectal cancer (CRC) despite combinatorial targeted therapies based on the latest understanding of signaling circuitry. To identify parallel resistance mechanisms induced by BRAF-MEK-EGFR co-targeting, we used a high-throughput kinase activity mapping platform. Here we show that SRC kinases are systematically activated in BRAFV600E CRC following targeted inhibition of BRAF ± EGFR and that coordinated targeting of SRC with BRAF ± EGFR increases treatment efficacy in vitro and in vivo. SRC drives resistance to BRAF ± EGFR targeted therapy independently of ERK signaling by inducing transcriptional reprogramming through ß-catenin (CTNNB1). The EGFR-independent compensatory activation of SRC kinases is mediated by an autocrine prostaglandin E2 loop that can be blocked with cyclooxygenase-2 (COX2) inhibitors. Co-targeting of COX2 with BRAF + EGFR promotes durable suppression of tumor growth in patient-derived tumor xenograft models. COX2 inhibition represents a drug-repurposing strategy to overcome therapeutic resistance in BRAFV600E CRC.


Assuntos
Neoplasias Colorretais , Proteínas Proto-Oncogênicas B-raf , Humanos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Sistema de Sinalização das MAP Quinases , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Receptores ErbB/genética , Quinases da Família src/genética , Quinases da Família src/uso terapêutico
3.
Acta Neuropathol ; 124(6): 875-81, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23161096

RESUMO

Embryonal tumor with multilayered rosettes (ETMR, previously known as ETANTR) is a highly aggressive embryonal CNS tumor, which almost exclusively affects infants and is associated with a dismal prognosis. Accurate diagnosis is of critical clinical importance because of its poor response to current treatment protocols and its distinct biology. Amplification of the miRNA cluster at 19q13.42 has been identified previously as a genetic hallmark for ETMR, but an immunohistochemistry-based assay for clinical routine diagnostics [such as INI-1 for atypical teratoid rhabdoid tumor (AT/RT)] is still lacking. In this study, we screened for an ETMR-specific marker using a gene-expression profiling dataset of more than 1,400 brain tumors and identified LIN28A as a highly specific marker for ETMR. The encoded protein binds small RNA and has been implicated in stem cell pluripotency, metabolism and tumorigenesis. Using an LIN28A specific antibody, we carried out immunohistochemical analysis of LIN28A in more than 800 childhood brain-tumor samples and confirmed its high specificity for ETMR. Strong LIN28A immunoexpression was found in all 37 ETMR samples tested, whereas focal reactivity was only present in a small (6/50) proportion of AT/RT samples. All other pediatric brain tumors were completely LIN28A-negative. In summary, we established LIN28A immunohistochemistry as a highly sensitive and specific, rapid, inexpensive diagnostic tool for routine pathological verification of ETMR.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Proteínas de Ligação a DNA/genética , Neoplasias Embrionárias de Células Germinativas/genética , Neurópilo/metabolismo , Adolescente , Neoplasias Encefálicas/patologia , Criança , Pré-Escolar , Diagnóstico Diferencial , Perfilação da Expressão Gênica/métodos , Humanos , MicroRNAs/genética , Neoplasias Embrionárias de Células Germinativas/patologia , Tumores Neuroectodérmicos Primitivos/genética , Tumores Neuroectodérmicos Primitivos/patologia , Neurópilo/patologia , Proteínas de Ligação a RNA , Tumor Rabdoide/genética , Tumor Rabdoide/patologia
4.
Nat Biotechnol ; 22(6): 724-31, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15146195

RESUMO

Because of their sensitivity to solubilizing detergents, membrane protein assemblies are difficult to study. We describe a protocol that covalently conserves protein interactions through time-controlled transcardiac perfusion cross-linking (tcTPC) before disruption of tissue integrity. To validate tcTPC for identifying protein-protein interactions, we established that tcTPC allowed stringent immunoaffinity purification of the gamma-secretase complex in high salt concentrations and detergents and was compatible with mass spectrometric identification of cross-linked aph-1, presenilin-1 and nicastrin. We then applied tcTPC to identify more than 20 proteins residing in the vicinity of the cellular prion protein (PrPC), suggesting that PrP is embedded in specialized membrane regions with a subset of molecules that, like PrP, use a glycosylphosphatidylinositol anchor for membrane attachment. Many of these proteins have been implicated in cell adhesion/neuritic outgrowth, and harbor immunoglobulin C2 and fibronectin type III-like motifs.


Assuntos
Encéfalo/metabolismo , Proteínas de Membrana/metabolismo , Perfusão/métodos , Mapeamento de Interação de Proteínas/métodos , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide , Animais , Ácido Aspártico Endopeptidases , Western Blotting , Química Encefálica , Procedimentos Cirúrgicos Cardíacos , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Reagentes de Ligações Cruzadas/química , Endopeptidases/química , Endopeptidases/imunologia , Endopeptidases/metabolismo , Formaldeído/química , Glicosilfosfatidilinositóis , Técnicas de Imunoadsorção , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/análise , Proteínas de Membrana/química , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Moléculas de Adesão de Célula Nervosa/análise , Moléculas de Adesão de Célula Nervosa/genética , Moléculas de Adesão de Célula Nervosa/metabolismo , Proteínas PrPC/análise , Proteínas PrPC/genética , Proteínas PrPC/metabolismo , Presenilina-1 , Espectrometria de Massas por Ionização por Electrospray , Tripsina/metabolismo
5.
J Neurosurg ; 120(2): 331-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24286145

RESUMO

OBJECT: The management of patients with locally recurrent or metastatic chordoma is a challenge. Preclinical disease models would greatly accelerate the development of novel therapeutic options for chordoma. The authors sought to establish and characterize a primary xenograft model for chordoma that faithfully recapitulates the molecular features of human chordoma. METHODS: Chordoma tissue from a recurrent clival tumor was obtained at the time of surgery and implanted subcutaneously into NOD-SCID interleukin-2 receptor gamma (IL-2Rγ) null (NSG) mouse hosts. Successful xenografts were established and passaged in the NSG mice. The recurrent chordoma and the derived human chordoma xenograft were compared by histology, immunohistochemistry, and phospho-specific immunohistochemistry. Based on these results, mice harboring subcutaneous chordoma xenografts were treated with the mTOR inhibitor MLN0128, and tumors were subjected to phosphoproteome profiling using Luminex technology and immunohistochemistry. RESULTS: SF8894 is a novel chordoma xenograft established from a recurrent clival chordoma that faithfully recapitulates the histopathological, immunohistological, and phosphoproteomic features of the human tumor. The PI3K/Akt/mTOR pathway was activated, as evidenced by diffuse immunopositivity for phospho-epitopes, in the recurrent chordoma and in the established xenograft. Treatment of mice harboring chordoma xenografts with MLN0128 resulted in decreased activity of the PI3K/Akt/mTOR signaling pathway as indicated by decreased phospho-mTOR levels (p = 0.019, n = 3 tumors per group). CONCLUSIONS: The authors report the establishment of SF8894, a recurrent clival chordoma xenograft that mimics many of the features of the original tumor and that should be a useful preclinical model for recurrent chordoma.


Assuntos
Cordoma/terapia , Xenoenxertos/patologia , Fósforo/metabolismo , Proteoma/fisiologia , Animais , Antineoplásicos/uso terapêutico , Cordoma/tratamento farmacológico , Cordoma/genética , Modelos Animais de Doenças , Epitopos , Xenoenxertos/efeitos dos fármacos , Xenoenxertos/crescimento & desenvolvimento , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos NOD , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Proteína Oncogênica v-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo
6.
Mol Cancer Res ; 10(7): 904-13, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22618028

RESUMO

The Hippo signaling pathway is functionally conserved in Drosophila melanogaster and mammals, and its proposed function is to control tissue homeostasis by regulating cell proliferation and apoptosis. The core components are composed of a kinase cascade that culminates with the phosphorylation and inhibition of Yes-associated protein 1 (YAP1). Phospho-YAP1 is retained in the cytoplasm. In the absence of Hippo signaling, YAP1 translocates to the nucleus, associates with co-activators TEAD1-4, and functions as a transcriptional factor promoting the expression of key target genes. Components of the Hippo pathway are mutated in human cancers, and deregulation of this pathway plays a role in tumorigenesis. Loss of the NF2 tumor suppressor gene is the most common genetic alteration in meningiomas, and the NF2 gene product, Merlin, acts upstream of the Hippo pathway. Here, we show that primary meningioma tumors have high nuclear expression of YAP1. In meningioma cells, Merlin expression is associated with phosphorylation of YAP1. Using an siRNA transient knockdown of YAP1 in NF2-mutant meningioma cells, we show that suppression of YAP1 impaired cell proliferation and migration. Conversely, YAP1 overexpression led to a strong augment of cell proliferation and anchorage-independent growth and restriction of cisplatin-induced apoptosis. In addition, expression of YAP1 in nontransformed arachnoidal cells led to the development of tumors in nude mice. Together, these findings suggest that in meningiomas, deregulation of the Hippo pathway is largely observed in primary tumors and that YAP1 functions as an oncogene promoting meningioma tumorigenesis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neoplasias Encefálicas , Meningioma , Fosfoproteínas , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Cisplatino/farmacologia , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Meningioma/genética , Meningioma/metabolismo , Camundongos , Neoplasias Experimentais/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , RNA Interferente Pequeno , Análise Serial de Tecidos , Fatores de Transcrição , Cicatrização , Proteínas de Sinalização YAP
7.
Neuro Oncol ; 14(9): 1146-52, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22753230

RESUMO

The signaling pathways that underlie the pathogenesis of pediatric gliomas are poorly understood. We characterized the PI3K/Akt/mTOR pathway in pediatric gliomas of all grades. Using immunohistochemistry, we assessed activation of the PI3K/Akt/mTOR pathway by evaluating the downstream signaling molecules phospho(p)-S6, phospho(p)-4BP1, and phospho(p)-PRAS40; PTEN; and PTEN promoter methylation, as well as the MIB labeling index. We correlated these findings with the clinical outcomes of 48 children with gliomas. Eighty percent of high-grade gliomas (12/15) showed activation of the PI3K/Akt/mTOR pathway based on p-S6 and p-4EBP1 expression. The majority of high-grade gliomas were negative for PTEN expression (10/15), and 50% had PTEN promoter methylation (grade III: 2/4; grade IV: 3/6). Low-grade gliomas demonstrated PI3K/Akt/mTOR pathway activation in 14/32 (43.8%) by p-S6 and 16/32 (50%) by p-4EBP1. Over 50% of grade I (6/11) and almost all grade II tumors (6/7) showed PTEN promoter methylation. Tumor grade correlated negatively with PTEN expression and positively with expression of p-S6 and p-4EBP1 (PTEN: P = .0025; pS6: P = .0075; p-4EBP1: P = .0066). There was a trend toward inverse correlation of methylation of the PTEN promoter with expression of PTEN protein (P= .0990) and direct correlation of expression of p-S6 and p-4EBP1 with poorer clinical outcome, as measured by progression-free survival (p-S6: P= .0874; p-4EBP1: P= .0475). Tumors with no PTEN expression had a higher MIB labeling index (P= .007). The majority of pediatric gliomas show activation of the PI3K/Akt/mTOR pathway, with methylation of the PTEN promoter occurring commonly in these tumors.


Assuntos
Metilação de DNA , Glioma/genética , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Adolescente , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Criança , Pré-Escolar , DNA de Neoplasias/genética , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Glioma/metabolismo , Glioma/mortalidade , Humanos , Técnicas Imunoenzimáticas , Lactente , Recém-Nascido , Masculino , Gradação de Tumores , PTEN Fosfo-Hidrolase/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais
8.
Cancer Cell ; 17(4): 362-75, 2010 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-20385361

RESUMO

The neural stem cell marker CD133 is reported to identify cells within glioblastoma (GBM) that can initiate neurosphere growth and tumor formation; however, instances of CD133(-) cells exhibiting similar properties have also been reported. Here, we show that some PTEN-deficient GBM tumors produce a series of CD133(+) and CD133(-) self-renewing tumor-initiating cell types and provide evidence that these cell types constitute a lineage hierarchy. Our results show that the capacities for self-renewal and tumor initiation in GBM need not be restricted to a uniform population of stemlike cells, but can be shared by a lineage of self-renewing cell types expressing a range of markers of forebrain lineage.


Assuntos
Neoplasias Encefálicas/patologia , Estruturas Celulares/patologia , Glioblastoma/patologia , Antígeno AC133 , Antígenos CD/análise , Antígenos CD/genética , Neoplasias Encefálicas/genética , Diferenciação Celular , Divisão Celular , Citometria de Fluxo , Perfilação da Expressão Gênica , Ligação Genética , Glioblastoma/genética , Glicoproteínas/análise , Glicoproteínas/deficiência , Glicoproteínas/genética , Humanos , Imuno-Histoquímica , Cinética , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/transplante , Peptídeos/análise , Peptídeos/deficiência , Peptídeos/genética
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