Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
2.
J Neurochem ; 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38372586

RESUMEN

Lipids play crucial roles in the susceptibility and brain cellular responses to Alzheimer's disease (AD) and are increasingly considered potential soluble biomarkers in cerebrospinal fluid (CSF) and plasma. To delineate the pathological correlations of distinct lipid species, we conducted a comprehensive characterization of both spatially localized and global differences in brain lipid composition in AppNL-G-F mice with spatial and bulk mass spectrometry lipidomic profiling, using human amyloid-expressing (h-Aß) and WT mouse brains controls. We observed age-dependent increases in lysophospholipids, bis(monoacylglycerol) phosphates, and phosphatidylglycerols around Aß plaques in AppNL-G-F mice. Immunohistology-based co-localization identified associations between focal pro-inflammatory lipids, glial activation, and autophagic flux disruption. Likewise, in human donors with varying Braak stages, similar studies of cortical sections revealed co-expression of lysophospholipids and ceramides around Aß plaques in AD (Braak stage V/VI) but not in earlier Braak stage controls. Our findings in mice provide evidence of temporally and spatially heterogeneous differences in lipid composition as local and global Aß-related pathologies evolve. Observing similar lipidomic changes associated with pathological Aß plaques in human AD tissue provides a foundation for understanding differences in CSF lipids with reported clinical stage or disease severity.

3.
Mol Biol Evol ; 40(1)2023 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-36585823

RESUMEN

Pangolins are one of nature's most fascinating species being scales covered and myrmecophagous diet, yet relatively little is known about the molecular basis. Here, we combine the multi-omics, evolution, and fundamental proteins feature analysis of both Chinese and Malayan pangolins, highlighting the molecular mechanism of both myrmecophagous diet and scale formation, representing a fascinating evolutionary strategy to occupy the unique ecological niches. In contrast to conserved organization of epidermal differentiation complex, pangolin has undergone large scale variation and gene loss events causing expression pattern and function conversion that contribute to cornified epithelium structures on stomach to adapt myrmecophagous diet. Our assemblies also enable us to discover large copies number of high glycine-tyrosine keratin-associated proteins (HGT-KRTAPs). In addition, highly homogenized tandem array, amino content, and the specific expression pattern further validate the strong connection between the molecular mechanism of scale hardness and HGT-KRTAPs.


Asunto(s)
Genoma , Pangolines , Animales , Dieta
4.
Nature ; 554(7691): 189-194, 2018 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-29420467

RESUMEN

Somatic mutations of ERBB2 and ERBB3 (which encode HER2 and HER3, respectively) are found in a wide range of cancers. Preclinical modelling suggests that a subset of these mutations lead to constitutive HER2 activation, but most remain biologically uncharacterized. Here we define the biological and therapeutic importance of known oncogenic HER2 and HER3 mutations and variants of unknown biological importance by conducting a multi-histology, genomically selected, 'basket' trial using the pan-HER kinase inhibitor neratinib (SUMMIT; clinicaltrials.gov identifier NCT01953926). Efficacy in HER2-mutant cancers varied as a function of both tumour type and mutant allele to a degree not predicted by preclinical models, with the greatest activity seen in breast, cervical and biliary cancers and with tumours that contain kinase domain missense mutations. This study demonstrates how a molecularly driven clinical trial can be used to refine our biological understanding of both characterized and new genomic alterations with potential broad applicability for advancing the paradigm of genome-driven oncology.


Asunto(s)
Mutación , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Quinolinas/farmacología , Quinolinas/uso terapéutico , Receptor ErbB-2/antagonistas & inhibidores , Receptor ErbB-3/antagonistas & inhibidores , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Mutación Missense , Neoplasias/enzimología , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Quinolinas/efectos adversos , Receptor ErbB-2/química , Receptor ErbB-2/genética , Receptor ErbB-3/química , Receptor ErbB-3/genética , Resultado del Tratamiento
5.
Opt Express ; 30(11): 18713-18729, 2022 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-36221667

RESUMEN

The velocity of cloud droplets has a significant effect on the investigation of the turbulence-cloud microphysics interaction mechanism. The paper proposes an in-line digital holographic interferometry (DHI) technique based on depth expansion and self-fusion algorithm to simultaneously extract particle velocity from eight holograms. In comparison to the two-frame exposure method, the extraction efficiency of velocity is raised by threefold, and the number of reference particles used for particle registration is increased to eight. The experimental results obtained in the cloud chamber show that the velocity of cloud droplets increases fourfold from the stabilization phase to the dissipation phase. The measurement deviations of two phases are 1.138 and 1.153 mm/s, respectively. Additionally, this method provides a rapid solution for three-dimensional particle velocimetry investigation of turbulent field stacking and cloud droplets collisions.

6.
J Cell Physiol ; 235(4): 3679-3689, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31637705

RESUMEN

Through the microarray analysis, long noncoding RNA TPT1-AS1 (TPT1-AS1) was identified in the development of glioma. However, the specific effect of TPT1-AS1 on glioma autophagy in the recent years has not fully been investigated. Therefore, the purpose of our present study is to investigate the function of TPT1-AS1 on affecting autophagy of glioma cells through regulation of microRNA-770-5p (miR-770-5p)-mediated stathmin 1 (STMN1). Initially, the expression of TPT1-AS1, miR-770-5p, and STMN1 were determined in glioma cell lines, followed by the prediction and validation of their interaction. After that, the effects of TPT1-AS1, miR-770-5p, and STMN1 on the in vitro glioma cell proliferation and autophagy were assessed using EdU assay and macrophage-derived chemokine (MDC) and on the in vivo tumor development and autophagy were evaluated using a nude mouse xenograft tumor assay and immunofluorescence assay. In comparison with the normal cells, the glioma cells displayed upregulated expression of TPT1-AS1 and STMN1, but a downregulated miR-770-5p expression. miR-770-5p, which directly targeted STMN1, could be downregulated by TPT1-AS1. Subsequently, in glioma cells, TPT1-AS1 can function to competitively bind to miR-770-5p, thus regulatEing STMN1 expression. Moreover, glioma cell proliferation and autophagy could be mediated through the TPT1-AS1/miR-770-5p/STMN1 axis. From our data we conclude an inhibitory function of TPT1-AS1 in glioma cell autophagy by downregulating miR-770-5p and upregulating STMN1, which may be instrumental for the therapeutic targeting and clinical management of glioma.


Asunto(s)
Glioma , MicroARNs , ARN Largo no Codificante , Animales , Humanos , Ratones , Apoptosis/genética , Autofagia/genética , Biomarcadores de Tumor/genética , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica/genética , Glioma/genética , Glioma/patología , Glioma/terapia , MicroARNs/genética , ARN Largo no Codificante/genética , Estatmina/genética , Proteína Tumoral Controlada Traslacionalmente 1 , Ensayos Antitumor por Modelo de Xenoinjerto , ARN sin Sentido
7.
Proc Natl Acad Sci U S A ; 111(43): 15544-9, 2014 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-25313082

RESUMEN

Previous studies have established that a subset of head and neck tumors contains human papillomavirus (HPV) sequences and that HPV-driven head and neck cancers display distinct biological and clinical features. HPV is known to drive cancer by the actions of the E6 and E7 oncoproteins, but the molecular architecture of HPV infection and its interaction with the host genome in head and neck cancers have not been comprehensively described. We profiled a cohort of 279 head and neck cancers with next generation RNA and DNA sequencing and show that 35 (12.5%) tumors displayed evidence of high-risk HPV types 16, 33, or 35. Twenty-five cases had integration of the viral genome into one or more locations in the human genome with statistical enrichment for genic regions. Integrations had a marked impact on the human genome and were associated with alterations in DNA copy number, mRNA transcript abundance and splicing, and both inter- and intrachromosomal rearrangements. Many of these events involved genes with documented roles in cancer. Cancers with integrated vs. nonintegrated HPV displayed different patterns of DNA methylation and both human and viral gene expressions. Together, these data provide insight into the mechanisms by which HPV interacts with the human genome beyond expression of viral oncoproteins and suggest that specific integration events are an integral component of viral oncogenesis.


Asunto(s)
Genoma Humano/genética , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/virología , Interacciones Huésped-Patógeno/genética , Papillomaviridae/fisiología , Secuencia de Bases , Metilación de ADN/genética , Regulación Neoplásica de la Expresión Génica , Genes Relacionados con las Neoplasias , Humanos , Datos de Secuencia Molecular , Integración Viral/genética
8.
J Biol Chem ; 289(7): 3869-75, 2014 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-24398677

RESUMEN

Exosomes are small vesicles (50-150 nm) of endocytic origin that are released by many different cell types. Exosomes in the tumor microenvironment may play a key role in facilitating cell-cell communication. Exosomes are reported to predominantly contain RNA and proteins. In this study, we investigated whether exosomes from pancreatic cancer cells and serum from patients with pancreatic ductal adenocarcinoma contain genomic DNA. Our results provide evidence that exosomes contain >10-kb fragments of double-stranded genomic DNA. Mutations in KRAS and p53 can be detected using genomic DNA from exosomes derived from pancreatic cancer cell lines and serum from patients with pancreatic cancer. In addition, using whole genome sequencing, we demonstrate that serum exosomes from patients with pancreatic cancer contain genomic DNA spanning all chromosomes. These results indicate that serum-derived exosomes can be used to determine genomic DNA mutations for cancer prediction, treatment, and therapy resistance.


Asunto(s)
Cromosomas Humanos , ADN de Neoplasias , Exosomas , Mutación , Neoplasias Pancreáticas , Proteínas Proto-Oncogénicas , Proteína p53 Supresora de Tumor , Proteínas ras , Línea Celular Tumoral , Cromosomas Humanos/genética , Cromosomas Humanos/metabolismo , Análisis Mutacional de ADN , ADN de Neoplasias/sangre , ADN de Neoplasias/genética , Exosomas/genética , Exosomas/metabolismo , Femenino , Humanos , Masculino , Neoplasias Pancreáticas/sangre , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Proteínas Proto-Oncogénicas/sangre , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas p21(ras) , Proteína p53 Supresora de Tumor/sangre , Proteína p53 Supresora de Tumor/genética , Proteínas ras/sangre , Proteínas ras/genética
9.
Nat Commun ; 14(1): 5247, 2023 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-37640701

RESUMEN

Microglial activation plays central roles in neuroinflammatory and neurodegenerative diseases. Positron emission tomography (PET) targeting 18 kDa Translocator Protein (TSPO) is widely used for localising inflammation in vivo, but its quantitative interpretation remains uncertain. We show that TSPO expression increases in activated microglia in mouse brain disease models but does not change in a non-human primate disease model or in common neurodegenerative and neuroinflammatory human diseases. We describe genetic divergence in the TSPO gene promoter, consistent with the hypothesis that the increase in TSPO expression in activated myeloid cells depends on the transcription factor AP1 and is unique to a subset of rodent species within the Muroidea superfamily. Finally, we identify LCP2 and TFEC as potential markers of microglial activation in humans. These data emphasise that TSPO expression in human myeloid cells is related to different phenomena than in mice, and that TSPO-PET signals in humans reflect the density of inflammatory cells rather than activation state.


Asunto(s)
Microglía , Enfermedades Neurodegenerativas , Animales , Ratones , Enfermedades Neurodegenerativas/genética , Macrófagos , Células Mieloides , Flujo Genético
10.
Chembiochem ; 13(5): 665-73, 2012 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-22334513

RESUMEN

The ubiquitously expressed Abl protein is a non-receptor tyrosine kinase that undergoes nuclear-cytoplasmic shuttling and is involved in many signaling pathways in the cell. Nuclear Abl is activated by DNA damage to regulate DNA repair, cell-cycle checkpoints and apoptosis. Previous studies have established that ataxia telangiectasia mutated (ATM) activates nuclear Abl by phosphorylating serine 465 (S465) in the kinase domain in response to ionizing radiation (IR). Using a peptide biosensor that specifically reports on the Abl kinase activity, we found that an Abl-S465A mutant, which is not capable of being activated by ATM through the canonical site, was still activated rapidly after IR. We established that DNA-dependent protein kinase (DNAPK) is likely to be responsible for a second pathway to activate Abl early on in the response to IR through phosphorylation at a site other than S465. Our findings show that nuclear and cytoplasmic Abl kinase is activated early on (within 5 min) in response to IR by both ATM and DNAPK, and that although one or the other of these kinases is required, either one is sufficient to activate Abl. These results support the concept of early Abl recruitment by both the ATM and the DNAPK pathways to regulate nuclear events triggered by DNA damage and potentially communicate them to proteins in the cytoplasm.


Asunto(s)
Técnicas Biosensibles/métodos , Rayos Infrarrojos , Péptidos/análisis , Proteínas Proto-Oncogénicas c-abl/metabolismo , Benzamidas , Células Cultivadas , Daño del ADN , Activación Enzimática/efectos de la radiación , Células HEK293 , Humanos , Mesilato de Imatinib , Morfolinas/farmacología , Péptidos/síntesis química , Péptidos/química , Fosforilación , Piperazinas/farmacología , Proteínas Proto-Oncogénicas c-abl/antagonistas & inhibidores , Pirimidinas/farmacología , Pironas/farmacología , Radiación Ionizante , Serina/metabolismo , Relación Estructura-Actividad
11.
Sci Adv ; 8(6): eabm2382, 2022 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-35138907

RESUMEN

Fusion genes represent a class of attractive therapeutic targets. Thousands of fusion genes have been identified in patients with cancer, but the functional consequences and therapeutic implications of most of these remain largely unknown. Here, we develop a functional genomic approach that consists of efficient fusion reconstruction and sensitive cell viability and drug response assays. Applying this approach, we characterize ~100 fusion genes detected in patient samples of The Cancer Genome Atlas, revealing a notable fraction of low-frequency fusions with activating effects on tumor growth. Focusing on those in the RTK-RAS pathway, we identify a number of activating fusions that can markedly affect sensitivity to relevant drugs. Last, we propose an integrated, level-of-evidence classification system to prioritize gene fusions systematically. Our study reiterates the urgent clinical need to incorporate similar functional genomic approaches to characterize gene fusions, thereby maximizing the utility of gene fusions for precision oncology.


Asunto(s)
Neoplasias , Fusión Génica , Genoma , Genómica , Humanos , Neoplasias/genética , Medicina de Precisión
12.
J Biol Chem ; 285(39): 30282-93, 2010 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-20624918

RESUMEN

Hepatitis B virus X protein (pX), implicated in hepatocarcinogenesis, induces DNA damage because of re-replication and allows propagation of damaged DNA, resulting in partial polyploidy and oncogenic transformation. The mechanism by which pX allows cells with DNA damage to continue proliferating is unknown. Herein, we show pX activates Polo-like kinase 1 (Plk1) in the G(2) phase, thereby attenuating the DNA damage checkpoint. Specifically, in the G(2) phase of pX-expressing cells, the checkpoint kinase Chk1 was inactive despite DNA damage, and protein levels of claspin, an adaptor of ataxia telangiectasia-mutated and Rad3-related protein-mediated Chk1 phosphorylation, were reduced. Pharmacologic inhibition or knockdown of Plk1 restored claspin protein levels, Chk1 activation, and p53 stabilization. Also, protein levels of DNA repair protein Mre11 were decreased in the G(2) phase of pX-expressing cells but not with Plk1 knockdown. Interestingly, in pX-expressing cells, Mre11 co-immunoprecipitated with transfected Plk1 Polo-box domain, and inhibition of Plk1 increased Mre11 stability in cycloheximide-treated cells. These results suggest that pX-activated Plk1 by down-regulating Mre11 attenuates DNA repair. Importantly, concurrent inhibition of Plk1, p53, and Mre11 increased the number of pX-expressing cells with DNA damage entering mitosis, relative to Plk1 inhibition alone. By contrast, inhibition or knockdown of Plk1 reduced pX-induced polyploidy while increasing apoptosis. We conclude Plk1, activated by pX, allows propagation of DNA damage by concurrently attenuating the DNA damage checkpoint and DNA repair, resulting in polyploidy. We propose this novel Plk1 mechanism initiates pX-mediated hepatocyte transformation.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Transformación Celular Viral , Daño del ADN , Reparación del ADN , Virus de la Hepatitis B/metabolismo , Poliploidía , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Transactivadores/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas de Ciclo Celular/genética , Línea Celular , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Fase G2/genética , Virus de la Hepatitis B/genética , Hepatocitos/metabolismo , Hepatocitos/virología , Humanos , Proteína Homóloga de MRE11 , Fosforilación/genética , Unión Proteica/genética , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Estabilidad Proteica , Proteínas Proto-Oncogénicas/genética , Transactivadores/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Reguladoras y Accesorias Virales , Quinasa Tipo Polo 1
13.
Artículo en Inglés | MEDLINE | ID: mdl-34250397

RESUMEN

PURPOSE: Cell-free DNA (cfDNA) analysis offers a noninvasive means to access the tumor genome. Despite limited sensitivity of broad-panel sequencing for detecting low-frequency mutations in cfDNA, it may enable more comprehensive genomic characterization in patients with sufficiently high disease burden. We investigated the utility of large-panel cfDNA sequencing in patients enrolled to a Phase I AKT1-mutant solid tumor basket study. METHODS: Patients had AKT1 E17K-mutant solid tumors and were treated on the multicenter basket study (ClinicalTrials.gov identifier: NCT01226316) of capivasertib, an AKT inhibitor. Serial plasma samples were prospectively collected and sequenced using exon-capture next-generation sequencing (NGS) analysis of 410 genes (Memorial Sloan Kettering [MSK]-Integrated Molecular Profiling of Actionable Cancer Target [IMPACT]) and allele-specific droplet digital polymerase chain reaction (ddPCR) for AKT1 E17K. Tumor DNA (tDNA) NGS (MSK-IMPACT) was also performed on available pretreatment tissue biopsy specimens. RESULTS: Among 25 patients, pretreatment plasma samples were sequenced to an average coverage of 504×. Somatic mutations were called in 20/25 (80%), with mutant allele fractions highly concordant with ddPCR of AKT1 E17K (r 2 = 0.976). Among 17 of 20 cfDNA-positive patients with available tDNA for comparison, mutational concordance was acceptable, with 82% of recurrent mutations shared between tissue and plasma. cfDNA NGS captured additional tumor heterogeneity, identifying mutations not observed in tDNA in 38% of patients, and revealed oncogenic mutations in patients without available baseline tDNA. Longitudinal cfDNA NGS (n = 98 samples) revealed distinct patterns of clonal dynamics in response to therapy. CONCLUSION: Large gene panel cfDNA NGS is feasible for patients with high disease burden and is concordant with single-analyte approaches, providing a robust alternative to ddPCR with greater breadth. cfDNA NGS can identify heterogeneity and potentially biologically informative and clinically relevant alterations.


Asunto(s)
ADN Tumoral Circulante/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Mutación , Neoplasias/genética , Genoma , Humanos , Estudios Prospectivos
14.
Genome Biol ; 20(1): 209, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31610796

RESUMEN

BACKGROUND: Genomic rearrangements exert a heavy influence on the molecular landscape of cancer. New analytical approaches integrating somatic structural variants (SSVs) with altered gene features represent a framework by which we can assign global significance to a core set of genes, analogous to established methods that identify genes non-randomly targeted by somatic mutation or copy number alteration. While recent studies have defined broad patterns of association involving gene transcription and nearby SSV breakpoints, global alterations in DNA methylation in the context of SSVs remain largely unexplored. RESULTS: By data integration of whole genome sequencing, RNA sequencing, and DNA methylation arrays from more than 1400 human cancers, we identify hundreds of genes and associated CpG islands (CGIs) for which the nearby presence of a somatic structural variant (SSV) breakpoint is recurrently associated with altered expression or DNA methylation, respectively, independently of copy number alterations. CGIs with SSV-associated increased methylation are predominantly promoter-associated, while CGIs with SSV-associated decreased methylation are enriched for gene body CGIs. Rearrangement of genomic regions normally having higher or lower methylation is often involved in SSV-associated CGI methylation alterations. Across cancers, the overall structural variation burden is associated with a global decrease in methylation, increased expression in methyltransferase genes and DNA damage response genes, and decreased immune cell infiltration. CONCLUSION: Genomic rearrangement appears to have a major role in shaping the cancer DNA methylome, to be considered alongside commonly accepted mechanisms including histone modifications and disruption of DNA methyltransferases.


Asunto(s)
Epigenoma , Variación Estructural del Genoma , Neoplasias/genética , Islas de CpG , Humanos
15.
Oncol Lett ; 15(5): 6077-6086, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29725392

RESUMEN

Highly conserved throughout evolution, the hedgehog (Hh) signalling pathway has been demonstrated to be involved in embryonic development, stem cell maintenance and tissue homeostasis in animals ranging from invertebrates to vertebrates. In the human body, a variety of cancer types are associated with the aberrantly activated Hh signalling pathway. Multiple studies have revealed suppressor of fused (Sufu) as a key negative regulator of this signalling pathway. In vertebrates, Sufu primarily functions as a tumor suppressor factor by interacting with and inhibiting glioma-associated oncogene homologues (GLIs), which are the terminal transcription factors of the Hh signalling pathway and belong to the Kruppel family of zinc finger proteins; by contrast, the regulation of Sufu itself remains relatively unclear. In the present review article, we focus on the effects of Sufu on the Hh signalling pathway in tumourigenesis and the molecular mechanisms underlying the regulation of GLI by Sufu. In addition, the factors modulating the activity of Sufu at post-transcriptional levels are also discussed.

16.
Cell Rep ; 24(2): 515-527, 2018 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-29996110

RESUMEN

A systematic cataloging of genes affected by genomic rearrangement, using multiple patient cohorts and cancer types, can provide insight into cancer-relevant alterations outside of exomes. By integrative analysis of whole-genome sequencing (predominantly low pass) and gene expression data from 1,448 cancers involving 18 histopathological types in The Cancer Genome Atlas, we identified hundreds of genes for which the nearby presence (within 100 kb) of a somatic structural variant (SV) breakpoint is associated with altered expression. While genomic rearrangements are associated with widespread copy-number alteration (CNA) patterns, approximately 1,100 genes-including overexpressed cancer driver genes (e.g., TERT, ERBB2, CDK12, CDK4) and underexpressed tumor suppressors (e.g., TP53, RB1, PTEN, STK11)-show SV-associated deregulation independent of CNA. SVs associated with the disruption of topologically associated domains, enhancer hijacking, or fusion transcripts are implicated in gene upregulation. For cancer-relevant pathways, SVs considerably expand our understanding of how genes are affected beyond point mutation or CNA.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Reordenamiento Génico/genética , Genes Relacionados con las Neoplasias , Genoma Humano , Neoplasias/genética , Secuencia de Bases , Carcinogénesis/genética , Carcinogénesis/patología , Variaciones en el Número de Copia de ADN/genética , Elementos de Facilitación Genéticos/genética , Humanos
17.
JCO Precis Oncol ; 20172017.
Artículo en Inglés | MEDLINE | ID: mdl-29629425

RESUMEN

Purpose: Ewing Sarcoma (ES) and Desmoplastic Small Round Cell Tumors (DSRCT) are aggressive sarcomas molecularly characterized by EWSR1 gene fusions. As pathognomonic genomic events in these respective tumor types, EWSR1 fusions represent robust potential biomarkers for disease monitoring. Patients and Methods: To investigate the feasibility of identifying EWSR1 fusions in plasma derived cell-free DNA (cfDNA) from ES and DSRCT patients, we evaluated two complementary approaches in samples from 17 patients with radiographic evidence of disease. The first approach involved identification of patient-specific genomic EWSR1 fusion breakpoints in formalin-fixed, paraffin-embedded tumor DNA using a broad, hybridization capture-based next generation sequencing (NGS) panel, followed by design of patient-specific droplet digital PCR (ddPCR) assays for plasma cfDNA interrogation . The second approach employed a disease-tailored targeted hybridization capture-based NGS panel applied directly to cfDNA which included EWSR1 as well as several other genes with potential prognostic utility. Results: EWSR1 fusions were identified in 11/11 (100%) ES and 5/6 (83%) DSRCT samples by ddPCR, while 10/11 (91%) and 4/6 (67%) were identified by NGS. The ddPCR approach had higher sensitivity, ranging between 0.009-0.018% sensitivity. However, the hybrid capture-based NGS assay identified the precise fusion breakpoints in the majority of cfDNA samples, as well as mutations in TP53 and STAG2, two other recurrent, clinically significant alterations in ES, all without prior knowledge of the tumor sequencing results. Conclusion: These results provide a compelling rationale for an integrated approach utilizing both NGS and ddPCR for plasma cfDNA-based biomarker evaluations in prospective cooperative group studies.

18.
Cancer Cell ; 31(6): 820-832.e3, 2017 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-28528867

RESUMEN

Molecular alterations involving the PI3K/AKT/mTOR pathway (including mutation, copy number, protein, or RNA) were examined across 11,219 human cancers representing 32 major types. Within specific mutated genes, frequency, mutation hotspot residues, in silico predictions, and functional assays were all informative in distinguishing the subset of genetic variants more likely to have functional relevance. Multiple oncogenic pathways including PI3K/AKT/mTOR converged on similar sets of downstream transcriptional targets. In addition to mutation, structural variations and partial copy losses involving PTEN and STK11 showed evidence for having functional relevance. A substantial fraction of cancers showed high mTOR pathway activity without an associated canonical genetic or genomic alteration, including cancers harboring IDH1 or VHL mutations, suggesting multiple mechanisms for pathway activation.


Asunto(s)
Neoplasias/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteogenómica , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Bases de Datos Genéticas , Perfilación de la Expresión Génica , Humanos , Mutación , Neoplasias/metabolismo , Transducción de Señal , Análisis de Supervivencia
19.
J Clin Oncol ; 34(20): 2404-15, 2016 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-27161972

RESUMEN

PURPOSE: Cancer spread to the central nervous system (CNS) often is diagnosed late and is unresponsive to therapy. Mechanisms of tumor dissemination and evolution within the CNS are largely unknown because of limited access to tumor tissue. MATERIALS AND METHODS: We sequenced 341 cancer-associated genes in cell-free DNA from cerebrospinal fluid (CSF) obtained through routine lumbar puncture in 53 patients with suspected or known CNS involvement by cancer. RESULTS: We detected high-confidence somatic alterations in 63% (20 of 32) of patients with CNS metastases of solid tumors, 50% (six of 12) of patients with primary brain tumors, and 0% (zero of nine) of patients without CNS involvement by cancer. Several patients with tumor progression in the CNS during therapy with inhibitors of oncogenic kinases harbored mutations in the kinase target or kinase bypass pathways. In patients with glioma, the most common malignant primary brain tumor in adults, examination of cell-free DNA uncovered patterns of tumor evolution, including temozolomide-associated mutations. CONCLUSION: The study shows that CSF harbors clinically relevant genomic alterations in patients with CNS cancers and should be considered for liquid biopsies to monitor tumor evolution in the CNS.


Asunto(s)
Neoplasias Encefálicas/líquido cefalorraquídeo , ADN de Neoplasias/líquido cefalorraquídeo , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Adulto , Anciano , Neoplasias Encefálicas/genética , Sistema Libre de Células , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación
20.
Mol Med Rep ; 12(3): 3563-3568, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26004555

RESUMEN

As a phosphatase, SHP-2 has been identified to be involved in regulating several cell functions, including growth, division, adhesion and motility. Therefore, SHP­2 may affect the response of glioma to radiotherapy, such as via enhancing angiogenesis. The present study aimed to investigate the function of SHP­2, a protein tyrosine phosphatase, in the radiosensitivity of glioma. U251, U87 and SHG44 glioma cell lines were transfected with small interfering (si)RNA against SHP­2 and cell proliferation was assessed using a cell counting kit 8 assay, cell apoptosis was assessed by fluorescence­activated cell sorting and immunoblotting, cell invasion was determined by an invasion assay, and the vasculogenic mimicry capacity was assessed by a tube formation assay. SHP­2 siRNA transfection reduced the proliferation and increased apoptosis in the glioma cell lines. Downregulation of SHP­2 suppressed glioma cell invasion and vasculogenic mimicry. These results demonstrated that no significant difference was observed between glioma tissues and normal brain tissues, however, silencing of SHP­2 inhibited cell proliferation, invasion and vasculogenic mimicry in the glioma cell lines. SHP­2 may be a novel therapeutic target for glioma.


Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Encéfalo/patología , Glioma/genética , Glioma/terapia , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética , ARN Interferente Pequeño/uso terapéutico , Adolescente , Adulto , Anciano , Encéfalo/irrigación sanguínea , Encéfalo/metabolismo , Neoplasias Encefálicas/irrigación sanguínea , Neoplasias Encefálicas/radioterapia , Línea Celular Tumoral , Femenino , Glioma/irrigación sanguínea , Glioma/radioterapia , Humanos , Masculino , Persona de Mediana Edad , ARN Interferente Pequeño/genética , Tratamiento con ARN de Interferencia , Transfección , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA