Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Cancer Res ; 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784426

RESUMO

The contribution of coding mutations to oncogenesis has been largely clarified whereas little is known about somatic mutations in noncoding DNA and their role in driving tumors remains controversial. Here, we used an alternative approach to interpret the functional significance of noncoding somatic mutations in promoting tumorigenesis. Noncoding somatic mutations of 151 neuroblastomas (NB) were integrated with ENCODE data to locate somatic mutations in regulatory elements specifically active in NB cells, non-specifically active in NB cells, and non-active. Within these types of elements, transcription factors (TFs) were identified whose binding sites (BS) were enriched or depleted in mutations. For these TFs, a gene expression signature was built to assess their implication in NB. DNA and RNA sequencing data were integrated to assess the effects of those mutations on mRNA levels. The pathogenicity of mutations was significantly higher in TFBS of regulatory elements specifically active in NB cells, as compared to the others. Within these elements, they were 18 over-represented TFs involved mainly in cell cycle phase transitions, and 15 under-represented TFs primarily regulating cell differentiation. A gene expression signature based on over-represented TFs correlated with poor survival and unfavourable prognostic markers. Moreover, recurrent mutations in TFBS of over-represented TFs such as EZH2 affected MCF2L and ADPRHL1 expression, among the others. We propose a novel approach to study the involvement of regulatory variants in NB that could be extended to other cancers and provide further evidence that alterations of gene expression may have relevant effects in NB development.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31876779

RESUMO

WT1-mutant Wilms tumors exhibit a high rate of concomitant CTNNB1 mutations, associated with activated Wnt signaling. Here, we show by laser and manual microdissection of different histologic cell types from 6 WT1-mutant tumor samples that 1 patient's tumor can contain up to 4 distinct mutations in CTNNB1 and/or WTX. Consecutive sections may also harbor different CTNNB1 mutations. The variability of activating CTNNB1 mutations demonstrates the multifocal nature of WT1-mutant Wilms tumors. As multiple independent tumors can occur in patients with constitutional WT1 mutations, they need to be surveyed more closely for tumor development.

3.
Mol Oncol ; 13(9): 1959-1975, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31293052

RESUMO

We have previously reported the expression of parathyroid hormone-like hormone (PTHLH) in well-differentiated, Schwannian stroma-rich neuroblastic tumors. The aim of this study was to functionally assess the role of PTHLH and its receptor, PTH1R, in neuroblastoma. Stable knockdown of PTHLH and PTH1R was conducted in neuroblastoma cell lines to investigate the succeeding phenotype induced both in vitro and in vivo. Downregulation of PTHLH reduced MYCN expression and subsequently induced cell cycle arrest, senescence, and migration and invasion impairment in a MYCN-amplified, TP53-mutated neuroblastoma cell line. These phenotypes were associated with reduced tumorigenicity in a murine model. We also show that PTHLH expression is not under the control of the calcium-sensing receptor in neuroblastoma. Conversely, its production is stimulated by epidermal growth factor receptor (EGFR). Accordingly, irreversible EGFR inhibition with canertinib abolished PTHLH expression. The oncogenic role of PTHLH appeared to be a consequence of its intracrine function, as downregulation of its receptor, PTH1R, increased anchorage-independent growth and induced a more undifferentiated, invasive phenotype. Respectively, high PTH1R mRNA expression was found in MYCN nonamplified primary tumors and also significantly associated with other prognostic factors of good outcome. This study provides the first evidence of the dual role of PTHLH in the behavior of neuroblastomas. Moreover, the identification of EGFR as a transcriptional regulator of PTHLH in neuroblastoma provides a novel therapeutic opportunity to promote a less aggressive tumor phenotype through irreversible inhibition of EGFR tyrosine kinase activity.

4.
Int J Cancer ; 143(11): 2828-2837, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30132831

RESUMO

A previous genome-wide association study (GWAS) identified common variation at the BARD1 locus as being highly associated with susceptibility to high-risk neuroblastoma, but the mechanisms underlying this association have been not extensively investigated. Here, we performed a fine mapping analysis of BARD1 locus (2q35) using GWAS data from 556 high-risk neuroblastoma patients and 2,575 controls of European-American ancestry, and identified two independent genome-wide neuroblastoma-associated loci. Functional single-nucleotide polymorphism (SNP) prioritization identified two causative variants that independently contributed to neuroblastoma risk, and each replicated robustly in multiple independent cohorts comprising 445 high-risk cases and 3,170 controls (rs17489363: combined p = 1.07 × 10-31 , OR:1.79, 95% CI:1.62-1.98 and rs1048108: combined p = 7.27 × 10-14 , OR:0.65, 95% CI:0.58-0.73). Particularly, the T risk allele of rs17489363 in the canonical promoter region of full-length BARD1 altered binding site of the transcription factor HSF1 and correlated with low expression of full-length BARD1 mRNA and protein. Low-level expression of full-length BARD1 associated with advanced neuroblastoma. In human neuroblastoma cells, attenuating full-length BARD1 increased proliferation and invasion capacity. In conclusion, we have identified two potentially causative SNPs at the BARD1 locus associated with predisposition to high-risk neuroblastoma, and have shown that full-length BARD1 may act as tumor suppressor.


Assuntos
Predisposição Genética para Doença/genética , Neuroblastoma/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Alelos , Estudos de Casos e Controles , Linhagem Celular Tumoral , Proliferação de Células/genética , Genes Supressores de Tumor/fisiologia , Estudo de Associação Genômica Ampla/métodos , Genótipo , Células HEK293 , Humanos , Lactente , Invasividade Neoplásica/genética , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética
5.
Nat Med ; 24(8): 1204-1215, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29967352

RESUMO

The failure to develop effective therapies for pediatric glioblastoma (pGBM) and diffuse intrinsic pontine glioma (DIPG) is in part due to their intrinsic heterogeneity. We aimed to quantitatively assess the extent to which this was present in these tumors through subclonal genomic analyses and to determine whether distinct tumor subpopulations may interact to promote tumorigenesis by generating subclonal patient-derived models in vitro and in vivo. Analysis of 142 sequenced tumors revealed multiple tumor subclones, spatially and temporally coexisting in a stable manner as observed by multiple sampling strategies. We isolated genotypically and phenotypically distinct subpopulations that we propose cooperate to enhance tumorigenicity and resistance to therapy. Inactivating mutations in the H4K20 histone methyltransferase KMT5B (SUV420H1), present in <1% of cells, abrogate DNA repair and confer increased invasion and migration on neighboring cells, in vitro and in vivo, through chemokine signaling and modulation of integrins. These data indicate that even rare tumor subpopulations may exert profound effects on tumorigenesis as a whole and may represent a new avenue for therapeutic development. Unraveling the mechanisms of subclonal diversity and communication in pGBM and DIPG will be an important step toward overcoming barriers to effective treatments.


Assuntos
Neoplasias do Tronco Encefálico/patologia , Glioblastoma/patologia , Animais , Neoplasias do Tronco Encefálico/genética , Carcinogênese/patologia , Separação Celular , Criança , Células Clonais , Genótipo , Glioblastoma/genética , Humanos , Camundongos Nus , Fenótipo , Células Tumorais Cultivadas
7.
Front Oncol ; 8: 127, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755954

RESUMO

Background and objective: Diffuse intrinsic pontine glioma (DIPG) is a lethal brainstem tumor in children. Dendritic cells (DCs) have T-cell stimulatory capacity and, therefore, potential antitumor activity for disease control. DCs vaccines have been shown to reactivate tumor-specific T cells in both clinical and preclinical settings. We designed a phase Ib immunotherapy (IT) clinical trial with the use of autologous dendritic cells (ADCs) pulsed with an allogeneic tumors cell-lines lysate in patients with newly diagnosed DIPG after irradiation (radiation therapy). Methods: Nine patients with newly diagnosed DIPG met enrollment criteria. Autologous dendritic cell vaccines (ADCV) were prepared from monocytes obtained by leukapheresis. Five ADCV doses were administered intradermally during induction phase. In the absence of tumor progression, patients received three boosts of tumor lysate every 3 months during the maintenance phase. Results: Vaccine fabrication was feasible in all patients included in the study. Non-specific KLH (9/9 patients) and specific (8/9 patients) antitumor response was identified by immunologic studies in peripheral blood mononuclear cells (PBMC). Immunological responses were also confirmed in the T lymphocytes isolated from the cerebrospinal fluid (CSF) of two patients. Vaccine administration resulted safe in all patients treated with this schema. Conclusion: These preliminary results demonstrate that ADCV preparation is feasible, safe, and generate a DIPG-specific immune response detected in PBMC and CSF. This strategy shows a promising backbone for future schemas of combination IT.

8.
Cancer Med ; 7(4): 1359-1368, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29542868

RESUMO

Wilms tumors (WT) with WT1 mutations do not respond well to preoperative chemotherapy by volume reduction, suggesting resistance to chemotherapy. The histologic pattern of this tumor subtype indicates an intrinsic mesenchymal differentiation potential. Currently, it is unknown whether cytotoxic treatments can induce a terminal differentiation state as a direct comparison of untreated and chemotherapy-treated tumor samples has not been reported so far. We conducted gene expression profiling of 11 chemotherapy and seven untreated WT1-mutant Wilms tumors and analyzed up- and down-regulated genes with bioinformatic methods. Cell culture experiments were performed from primary Wilms tumors and genetic alterations in WT1 and CTNNB1 analyzed. Chemotherapy induced MYF6 165-fold and several MYL and MYH genes more than 20-fold and repressed many genes from cell cycle process networks. Viable tumor cells could be cultivated when patients received less than 8 weeks of chemotherapy but not in two cases with longer treatments. In one case, viable cells could be extracted from a lung metastasis occurring after 6 months of intensive chemotherapy and radiation. Comparison of primary tumor and metastasis cells from the same patient revealed up-regulation of RELN and TBX2, TBX4 and TBX5 genes and down-regulation of several HOXD genes. Our analyses demonstrate that >8 weeks of chemotherapy can induce terminal myogenic differentiation in WT1-mutant tumors, but this is not associated with volume reduction. The time needed for all tumor cells to achieve the terminal differentiation state needs to be evaluated. In contrast, prolonged treatments can result in genetic alterations leading to resistance.


Assuntos
Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Mutação , Proteínas WT1/genética , Tumor de Wilms/genética , Tumor de Wilms/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais , Ciclo Celular/genética , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/secundário , Desenvolvimento Muscular/genética , Transcrição Genética , Tumor de Wilms/tratamento farmacológico
9.
Genome Med ; 10(1): 25, 2018 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-29592813

RESUMO

While tumor genome sequencing has become widely available in clinical and research settings, the interpretation of tumor somatic variants remains an important bottleneck. Here we present the Cancer Genome Interpreter, a versatile platform that automates the interpretation of newly sequenced cancer genomes, annotating the potential of alterations detected in tumors to act as drivers and their possible effect on treatment response. The results are organized in different levels of evidence according to current knowledge, which we envision can support a broad range of oncology use cases. The resource is publicly available at http://www.cancergenomeinterpreter.org .


Assuntos
Genoma Humano , Anotação de Sequência Molecular , Neoplasias/genética , Software , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/metabolismo , Bases de Dados Genéticas , Genes Neoplásicos , Humanos , Mutação/genética , Neoplasias/tratamento farmacológico
10.
Biosens Bioelectron ; 107: 62-68, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29438908

RESUMO

In this work, we propose for the first time the use of anodic aluminum oxide (AAO) nanoporous membranes for in situ monitoring of parathyroid hormone-like hormone (PTHLH) secretion in cultured human cells. The biosensing system is based on the nanochannels blockage upon immunocomplex formation, which is electrically monitored through the voltammetric oxidation of Prussian blue nanoparticles (PBNPs). Models evaluated include a neuroblastoma cell line (SK-N-AS) and immortalized keratinocytes (HaCaT) as a control of high PTHLH production. The effect of total number of seeded cells and incubation time on the secreted PTHLH levels is assessed, finding that secreted PTHLH levels range from approximately 60 to 400 ng/mL. Moreover, our methodology is also applied to analyse PTHLH production following PTHLH gene knockdown upon transient cell transfection with a specific silencing RNA (siRNA). Given that inhibition of PTHLH secretion reduces cell proliferation, survival and invasiveness in a number of tumors, our system provides a powerful tool for the preclinical evaluation of therapies that regulate PTHLH production. This nanoporous membrane - based sensing technology might be useful to monitor the active secretion of other proteins as well, thus contributing to characterize their regulation and function.


Assuntos
Técnicas Biossensoriais/instrumentação , Membranas Artificiais , Nanoporos/ultraestrutura , Neuroblastoma/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Desenho de Equipamento , Humanos , Proteína Relacionada ao Hormônio Paratireóideo/análise
11.
Clin Cancer Res ; 24(6): 1355-1363, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29351917

RESUMO

Purpose: The classification of medulloblastoma into WNT, SHH, group 3, and group 4 subgroups has become of critical importance for patient risk stratification and subgroup-tailored clinical trials. Here, we aimed to develop a simplified, clinically applicable classification approach that can be implemented in the majority of centers treating patients with medulloblastoma.Experimental Design: We analyzed 1,577 samples comprising previously published DNA methylation microarray data (913 medulloblastomas, 457 non-medulloblastoma tumors, 85 normal tissues), and 122 frozen and formalin-fixed paraffin-embedded medulloblastoma samples. Biomarkers were identified applying stringent selection filters and Linear Discriminant Analysis (LDA) method, and validated using DNA methylation microarray data, bisulfite pyrosequencing, and direct-bisulfite sequencing.Results: Using a LDA-based approach, we developed and validated a prediction method (EpiWNT-SHH classifier) based on six epigenetic biomarkers that allowed for rapid classification of medulloblastoma into the clinically relevant subgroups WNT, SHH, and non-WNT/non-SHH with excellent concordance (>99%) with current gold-standard methods, DNA methylation microarray, and gene signature profiling analysis. The EpiWNT-SHH classifier showed high prediction capacity using both frozen and formalin-fixed material, as well as diverse DNA methylation detection methods. Similarly, we developed a classifier specific for group 3 and group 4 tumors, based on five biomarkers (EpiG3-G4) with good discriminatory capacity, allowing for correct assignment of more than 92% of tumors. EpiWNT-SHH and EpiG3-G4 methylation profiles remained stable across tumor primary, metastasis, and relapse samples.Conclusions: The EpiWNT-SHH and EpiG3-G4 classifiers represent a new simplified approach for accurate, rapid, and cost-effective molecular classification of single medulloblastoma DNA samples, using clinically applicable DNA methylation detection methods. Clin Cancer Res; 24(6); 1355-63. ©2018 AACR.


Assuntos
Biomarcadores Tumorais , Neoplasias Cerebelares/diagnóstico , Neoplasias Cerebelares/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Meduloblastoma/diagnóstico , Meduloblastoma/genética , Biópsia , Ilhas de CpG , Metilação de DNA , Epigênese Genética , Epigenômica/métodos , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Reprodutibilidade dos Testes
12.
Oncotarget ; 8(52): 89775-89792, 2017 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-29163787

RESUMO

Pediatric tumors arise upon oncogenic transformation of stem/progenitor cells during embryonic development. Given this scenario, the existence of non-tumorigenic stem cells included within the aberrant tumoral niche, with a potential role in tumor biology, is an intriguing and unstudied possibility. Here, we describe the presence and function of non-tumorigenic neural crest-derived progenitor cells in aggressive neuroblastoma (NB) tumors. These cells differentiate into neural crest typical mesectodermal derivatives, giving rise to tumor stroma and promoting proliferation and tumor aggressiveness. Furthermore, an analysis of gene expression profiles in stage 4/M NB revealed a neural crest stem cell (NCSC) gene signature that was associated to stromal phenotype and high probability of relapse. Thus, this NCSC gene expression signature could be used in prognosis to improve stratification of stage 4/M NB tumors. Our results might facilitate the design of new therapies by targeting NCSCs and their contribution to tumor stroma.

13.
Cancer Cell ; 32(4): 520-537.e5, 2017 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-28966033

RESUMO

We collated data from 157 unpublished cases of pediatric high-grade glioma and diffuse intrinsic pontine glioma and 20 publicly available datasets in an integrated analysis of >1,000 cases. We identified co-segregating mutations in histone-mutant subgroups including loss of FBXW7 in H3.3G34R/V, TOP3A rearrangements in H3.3K27M, and BCOR mutations in H3.1K27M. Histone wild-type subgroups are refined by the presence of key oncogenic events or methylation profiles more closely resembling lower-grade tumors. Genomic aberrations increase with age, highlighting the infant population as biologically and clinically distinct. Uncommon pathway dysregulation is seen in small subsets of tumors, further defining the molecular diversity of the disease, opening up avenues for biological study and providing a basis for functionally defined future treatment stratification.


Assuntos
Neoplasias do Tronco Encefálico/genética , Glioma/genética , Histonas/genética , Mutação , Adolescente , Neoplasias do Tronco Encefálico/patologia , Proteínas de Ciclo Celular/genética , Criança , Pré-Escolar , DNA Topoisomerases Tipo I/genética , Exoma , Proteínas F-Box/genética , Proteína 7 com Repetições F-Box-WD , Feminino , Dosagem de Genes , Glioma/patologia , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Ubiquitina-Proteína Ligases/genética , Adulto Jovem
14.
Sci Rep ; 7(1): 11762, 2017 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-28924151

RESUMO

This work provides a comprehensive CpG methylation landscape of the different layers of the human eye that unveils the gene networks associated with their biological functions and how these are disrupted in common visual disorders. Herein, we firstly determined the role of CpG methylation in the regulation of ocular tissue-specification and described hypermethylation of retinal transcription factors (i.e., PAX6, RAX, SIX6) in a tissue-dependent manner. Second, we have characterized the DNA methylome of visual disorders linked to internal and external environmental factors. Main conclusions allow certifying that crucial pathways related to Wnt-MAPK signaling pathways or neuroinflammation are epigenetically controlled in the fibrotic disorders involved in retinal detachment, but results also reinforced the contribution of neurovascularization (ETS1, HES5, PRDM16) in diabetic retinopathy. Finally, we had studied the methylome in the most frequent intraocular tumors in adults and children (uveal melanoma and retinoblastoma, respectively). We observed that hypermethylation of tumor suppressor genes is a frequent event in ocular tumors, but also unmethylation is associated with tumorogenesis. Interestingly, unmethylation of the proto-oncogen RAB31 was a predictor of metastasis risk in uveal melanoma. Loss of methylation of the oncogenic mir-17-92 cluster was detected in primary tissues but also in blood from patients.


Assuntos
Metilação de DNA , DNA de Neoplasias , Retinopatia Diabética , Epigênese Genética , Neoplasias Oculares/metabolismo , Proteínas do Olho , Olho , Regulação Neoplásica da Expressão Gênica , Sistema de Sinalização das MAP Quinases , Proteínas de Neoplasias , Neovascularização Retiniana , Adulto , Criança , Pré-Escolar , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Retinopatia Diabética/genética , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Olho/crescimento & desenvolvimento , Olho/patologia , Neoplasias Oculares/genética , Neoplasias Oculares/patologia , Proteínas do Olho/biossíntese , Proteínas do Olho/genética , Feminino , Humanos , Masculino , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Neovascularização Retiniana/genética , Neovascularização Retiniana/metabolismo , Neovascularização Retiniana/patologia
15.
J Clin Oncol ; 35(25): 2934-2941, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28727518

RESUMO

Purpose BRAF V600E is a potentially highly targetable mutation detected in a subset of pediatric low-grade gliomas (PLGGs). Its biologic and clinical effect within this diverse group of tumors remains unknown. Patients and Methods A combined clinical and genetic institutional study of patients with PLGGs with long-term follow-up was performed (N = 510). Clinical and treatment data of patients with BRAF V600E mutated PLGG (n = 99) were compared with a large international independent cohort of patients with BRAF V600E mutated-PLGG (n = 180). Results BRAF V600E mutation was detected in 69 of 405 patients (17%) with PLGG across a broad spectrum of histologies and sites, including midline locations, which are not often routinely biopsied in clinical practice. Patients with BRAF V600E PLGG exhibited poor outcomes after chemotherapy and radiation therapies that resulted in a 10-year progression-free survival of 27% (95% CI, 12.1% to 41.9%) and 60.2% (95% CI, 53.3% to 67.1%) for BRAF V600E and wild-type PLGG, respectively ( P < .001). Additional multivariable clinical and molecular stratification revealed that the extent of resection and CDKN2A deletion contributed independently to poor outcome in BRAF V600E PLGG. A similar independent role for CDKN2A and resection on outcome were observed in the independent cohort. Quantitative imaging analysis revealed progressive disease and a lack of response to conventional chemotherapy in most patients with BRAF V600E PLGG. Conclusion BRAF V600E PLGG constitutes a distinct entity with poor prognosis when treated with current adjuvant therapy.


Assuntos
Neoplasias Encefálicas/enzimologia , Glioma/enzimologia , Proteínas Proto-Oncogênicas B-raf/genética , Adolescente , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Neoplasias do Tronco Encefálico/enzimologia , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/patologia , Neoplasias do Tronco Encefálico/terapia , Criança , Pré-Escolar , Estudos de Coortes , Diencéfalo/enzimologia , Diencéfalo/patologia , Feminino , Glioma/genética , Glioma/patologia , Glioma/terapia , Humanos , Lactente , Masculino , Mutação , Gradação de Tumores , Prognóstico
16.
J Control Release ; 255: 108-119, 2017 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-28412222

RESUMO

Neuroblastoma is a pediatric solid tumor with high expression of the tumor associated antigen disialoganglioside GD2. Despite initial response to induction therapy, nearly 50% of high-risk neuroblastomas recur because of chemoresistance. Here we encapsulated the topoisomerase-I inhibitor SN-38 in polymeric nanoparticles (NPs) surface-decorated with the anti-GD2 mouse mAb 3F8 at a mean density of seven antibody molecules per NP. The accumulation of drug-loaded NPs targeted with 3F8 versus with control antibody was monitored by microdialysis in patient-derived GD2-expressing neuroblastoma xenografts. We showed that the extent of tumor penetration by SN-38 was significantly higher in mice receiving the targeted nano-drug delivery system when compared to non-targeted system or free drug. This selective penetration of the tumor extracellular fluid translated into a strong anti-tumor effect prolonging survival of mice bearing GD2-high neuroblastomas in vivo.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Camptotecina/análogos & derivados , Líquido Extracelular/metabolismo , Imunoglobulina G/administração & dosagem , N-Acetilgalactosaminiltransferases/antagonistas & inibidores , Nanopartículas/administração & dosagem , Neuroblastoma/metabolismo , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais Murinos , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacocinética , Camptotecina/administração & dosagem , Camptotecina/química , Camptotecina/farmacocinética , Linhagem Celular Tumoral , Pré-Escolar , Liberação Controlada de Fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Imunoglobulina G/química , Irinotecano , Masculino , Camundongos Nus , N-Acetilgalactosaminiltransferases/genética , N-Acetilgalactosaminiltransferases/imunologia , N-Acetilgalactosaminiltransferases/metabolismo , Nanopartículas/química , Neuroblastoma/tratamento farmacológico , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Nat Med ; 23(4): 483-492, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28263309

RESUMO

Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumor that is located in the pons and primarily affects children. Nearly 80% of DIPGs harbor mutations in histone H3 genes, wherein lysine 27 is substituted with methionine (H3K27M). H3K27M has been shown to inhibit polycomb repressive complex 2 (PRC2), a multiprotein complex responsible for the methylation of H3 at lysine 27 (H3K27me), by binding to its catalytic subunit EZH2. Although DIPGs with the H3K27M mutation show global loss of H3K27me3, several genes retain H3K27me3. Here we describe a mouse model of DIPG in which H3K27M potentiates tumorigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M-expressing tumors require PRC2 for proliferation. Furthermore, we demonstrate that small-molecule EZH2 inhibitors abolish tumor cell growth through a mechanism that is dependent on the induction of the tumor-suppressor protein p16INK4A. Genome-wide enrichment analyses show that the genes that retain H3K27me3 in H3K27M cells are strong polycomb targets. Furthermore, we find a highly significant overlap between genes that retain H3K27me3 in the DIPG mouse model and in human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M-expressing DIPGs, and that inhibition of EZH2 is a potential therapeutic strategy for the treatment of these tumors.


Assuntos
Neoplasias do Tronco Encefálico/genética , Proliferação de Células/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Glioma/genética , Histonas/genética , Animais , Benzamidas/farmacologia , Neoplasias Encefálicas/genética , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Cromatografia Líquida , Inibidor p16 de Quinase Dependente de Ciclina/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/genética , Modelos Animais de Doenças , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Técnicas de Inativação de Genes , Glioblastoma/genética , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Indazóis/farmacologia , Camundongos , Camundongos SCID , Terapia de Alvo Molecular , Mutação , Transplante de Neoplasias , Células-Tronco Neurais , Complexo Repressor Polycomb 2/genética , Piridonas/farmacologia , Espectrometria de Massas em Tandem , Proteína Supressora de Tumor p14ARF/efeitos dos fármacos , Proteína Supressora de Tumor p14ARF/genética
18.
Mol Carcinog ; 56(4): 1281-1289, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27862333

RESUMO

We have previously reported that the calcium-sensing receptor (CaSR) is expressed in benign, differentiated neuroblastic tumors, and epigenetically silenced in undifferentiated, malignant cases. Furthermore, cinacalcet, an allosteric activator of the CaSR, reduces neuroblastoma tumor growth in preclinical models. However, to identify patients that might benefit from this treatment, a complete understanding of mechanisms governing CaSR expression in these tumors would be required. We have now analyzed two polymorphisms in the promoter region of the CASR gene (rs7652589 and rs1501899) by allelic discrimination in neuroblastoma patients and cell lines. Association of genotypes and haplotypes with CaSR mRNA levels and CASR promoter P2 methylation status was determined. Data presented show that minor alleles rs7652589 and rs1501899, present either in homo- or heterozygosis, were correlated with reduced CaSR mRNA levels in matching primary tumors and this association was independent of CASR promoter P2 hypermethylation. Haplotype AA was independently associated with reduced CaSR expression after adjusting by promoter P2 methylation status. These polymorphisms were identified in some ganglioneuromas in which CaSR expression is low despite exhibiting a high degree of differentiation. Furthermore, homozygous variants rs7652589 and rs1501899 were detected in SH-SY5Y cells, which are devoid of CaSR expression in the absence of hypermethylation of CASR promoter P2. In summary, minor alleles rs7652589 and rs1501899 are associated with reduced CaSR expression in neuroblastic tumors and neuroblastoma cell lines in which the CASR gene promoter P2 is not hypermethylated. Therefore, they potentially represent an additional mechanism of CASR transcriptional regulation in this group of developmental malignancies. © 2016 Wiley Periodicals, Inc.


Assuntos
Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Neuroblastoma/genética , Neoplasias do Sistema Nervoso Periférico/genética , Polimorfismo de Nucleotídeo Único , Receptores de Detecção de Cálcio/genética , Linhagem Celular Tumoral , Metilação de DNA , Intervalo Livre de Doença , Variação Genética , Haplótipos , Humanos , Lactente , Neuroblastoma/epidemiologia , Neoplasias do Sistema Nervoso Periférico/epidemiologia , Regiões Promotoras Genéticas
19.
Oncotarget ; 7(29): 46283-46300, 2016 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-27317769

RESUMO

Ewing sarcoma (ES) is an aggressive tumor defined by EWSR1 gene fusions that behave as an oncogene. Here we demonstrate that RING1B is highly expressed in primary ES tumors, and its expression is independent of the fusion oncogene. RING1B-depleted ES cells display an expression profile enriched in genes functionally involved in hematological development but RING1B depletion does not induce cellular differentiation. In ES cells, RING1B directly binds the SCN8A sodium channel promoter and its depletion results in enhanced Nav1.6 expression and function. The signaling pathway most significantly modulated by RING1B is NF-κB. RING1B depletion results in enhanced p105/p50 expression, which sensitizes ES cells to apoptosis by FGFR/SHP2/STAT3 blockade. Reduced NaV1.6 function protects ES cells from apoptotic cell death by maintaining low NF-κB levels. Our findings identify RING1B as a trait of the cell-of-origin and provide a potential targetable vulnerability.


Assuntos
Neoplasias Ósseas/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.6/metabolismo , NF-kappa B/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Sarcoma de Ewing/metabolismo , Transdução de Sinais , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Humanos , Sarcoma de Ewing/genética , Sarcoma de Ewing/patologia , Transdução de Sinais/fisiologia , Células Tumorais Cultivadas
20.
Cancer Lett ; 380(1): 10-9, 2016 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-27319373

RESUMO

Translational research in retinoblastoma - a pediatric tumor that originates during the development of the retina - would be improved by the creation of new patient-derived models. Using tumor samples from enucleated eyes we established a new battery of preclinical models that grow in vitro in serum-free medium and in vivo in immunodeficient mice. To examine whether the new xenografts recapitulate human disease and disseminate from the retina to the central nervous system, we evaluated their histology and the presence of molecular markers of dissemination that are used in the clinical setting to detect extraocular metastases. We evaluated GD2 synthase and CRX as such markers and generated a Taqman real-time quantitative PCR method to measure CRX mRNA for rapid, sensitive and specific quantification of local and metastatic tumor burden. This approach was able to detect 1 human retinoblastoma cell in 100.000 mouse brain cells. Our research adds novel preclinical tools for the discovery of new retinoblastoma treatments for clinical translation.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/enzimologia , Movimento Celular , Proteínas de Homeodomínio/metabolismo , N-Acetilgalactosaminiltransferases/metabolismo , Neoplasias Experimentais/enzimologia , Neoplasias da Retina/enzimologia , Retinoblastoma/enzimologia , Transativadores/metabolismo , Animais , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/secundário , Linhagem Celular Tumoral , Pré-Escolar , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Proteínas de Homeodomínio/genética , Humanos , Lactente , Camundongos Nus , N-Acetilgalactosaminiltransferases/genética , Micrometástase de Neoplasia , Transplante de Neoplasias , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias da Retina/genética , Neoplasias da Retina/patologia , Retinoblastoma/genética , Retinoblastoma/secundário , Transdução de Sinais , Transativadores/genética , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA