Search results for "Neuroblast"
showing 10 items of 348 documents
Digital Image Analysis Applied to Tumor Cell Proliferation, Aggressiveness, and Migration-Related Protein Synthesis in Neuroblastoma 3D Models
2020
Patient-derived cancer 3D models are a promising tool that will revolutionize personalized cancer therapy but that require previous knowledge of optimal cell growth conditions and the most advantageous parameters to evaluate biomimetic relevance and monitor therapy efficacy. This study aims to establish general guidelines on 3D model characterization phenomena, focusing on neuroblastoma. We generated gelatin-based scaffolds with different stiffness and performed SK-N-BE(2) and SH-SY5Y aggressive neuroblastoma cell cultures, also performing co-cultures with mouse stromal Schwann cell line (SW10). Model characterization by digital image analysis at different time points revealed that cell pro…
Focal DNA Copy Number Changes in Neuroblastoma Target MYCN Regulated Genes
2013
Neuroblastoma is an embryonic tumor arising from immature sympathetic nervous system cells. Recurrent genomic alterations include MYCN and ALK amplification as well as recurrent patterns of gains and losses of whole or large partial chromosome segments. A recent whole genome sequencing effort yielded no frequently recurring mutations in genes other than those affecting ALK. However, the study further stresses the importance of DNA copy number alterations in this disease, in particular for genes implicated in neuritogenesis. Here we provide additional evidence for the importance of focal DNA copy number gains and losses, which are predominantly observed in MYCN amplified tumors. A focal 5 kb…
Subventricular zone in motor neuron disease with frontotemporal dementia.
2011
Investigate how the subventricular proliferation and organisation is modified in a patient with FTLD-ALS. We studied the subventricular zone (SVZ) of a patient with FTLD-ALS immunohistochemical and histologically. We found an increase of Ki-67 positive cells and neuroblast in the subventricular zone, suggesting an activation of proliferating activity in response to FTD-ALS. This proliferation can act as a compensatory mechanism for rapid neuronal death and its modulation could provide a new therapeutic pathway in ALS. These results suggest a modification of neurogenesis in FTD-ALS. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
Aβ Oligomers and Fibrillar Aggregates Induce Different Apoptotic Pathways in LAN5 Neuroblastoma Cell Cultures
2009
Fibril deposit formation of amyloid beta-protein (Abeta) in the brain is a hallmark of Alzheimer's disease (AD). Increasing evidence suggests that toxicity is linked to diffusible Abeta oligomers, which have been found in soluble brain extracts of AD patients, rather than to insoluble fibers. Here we report a study of the toxicity of two distinct forms of recombinant Abeta small oligomers and fibrillar aggregates to simulate the action of diffusible Abeta oligomers and amyloid plaques on neuronal cells. Different techniques, including dynamic light scattering, fluorescence, and scanning electron microscopy, have been used to characterize the two forms of Abeta. Under similar conditions and …
Recruitment of HIF-1α and HIF-2α to common target genes is differentially regulated in neuroblastoma: HIF-2α promotes an aggressive phenotype
2006
In neuroblastoma specimens, HIF-2alpha but not HIF-1alpha is strongly expressed in well-vascularized areas. In vitro, HIF-2alpha protein was stabilized at 5% O2 (resembling end capillary oxygen conditions) and, in contrast to the low HIF-1alpha activity at this oxygen level, actively transcribed genes like VEGF. Under hypoxia (1% O2), HIF-1alpha was transiently stabilized and primarily mediated acute responses, whereas HIF-2alpha protein gradually accumulated and governed prolonged hypoxic gene activation. Knockdown of HIF-2alpha reduced growth of neuroblastoma tumors in athymic mice. Furthermore, high HIF-2alpha protein levels were correlated with advanced clinical stage and high VEGF expr…
Búsqueda de dianas terapéuticas en los puntos de contacto de la célula tumoral con su matriz extracelular en tumores neuroblásticos
2020
El neuroblastoma es un tumor embrionario del sistema nervioso simpático que representa el 15% de las muertes relacionadas con cáncer en la infancia. Se caracteriza por un amplio espectro de comportamientos clínicos derivados de su gran heterogeneidad en la presentación clínica y en los rasgos biológicos y genéticos. La clasificación de riesgo pre-tratamiento desempeña un papel central en la mejora de la supervivencia en estos pacientes, sin embargo, el subgrupo de pacientes de alto riesgo continúa teniendo una tasa de mortalidad particularmente alta, destacando la necesidad de identificar y validar nuevas terapias, modelos preclínicos y marcadores de respuesta terapéutica. Por este motivo, …
High levels of HIF-2α highlight an immature neural crest-like neuroblastoma cell cohort located in a perivascular niche
2007
High HIF-2alpha protein levels in the sympathetic nervous system-derived childhood tumour neuroblastoma as well as immature phenotype correlate to unfavourable outcome. Here we show that a small subset of perivascularly located, strongly HIF-2alpha-positive tumour cells (MYCN amplified) lacks expression of differentiation markers, but expresses neural crest and early sympathetic progenitor marker genes such as Notch-1, HES-1, c-Kit, dHAND, and vimentin. HIF-2alpha- and CD68-positive tumour-associated macrophages were frequently found close to the immature and HIF-2alpha-positive neuroblastoma cells and as VEGF levels are high in the perivascular niche, we hypothesize that neuroblastoma neur…
Evidence for differential and redundant function of the Sox genes Dichaete and SoxN during CNS development in Drosophila.
2002
Group B Sox-domain proteins encompass a class of conserved DNA-binding proteins expressed from the earliest stages of metazoan CNS development. In all higher organisms studied to date, related Group B Sox proteins are co-expressed in the developing CNS; in vertebrates there are three (Sox1, Sox2 and Sox3) and in Drosophila there are two (SoxNeuro and Dichaete). It has been suggested there may be a degree of functional redundancy in Sox function during CNS development. We describe the CNS phenotype of a null mutation in the Drosophila SoxNeuro gene and provide the first direct evidence for both redundant and differential Sox function during CNS development in Drosophila. In the lateral neuro…
Primary culture of single ectodermal precursors of Drosophila reveals a dorsoventral prepattern of intrinsic neurogenic and epidermogenic capabilitie…
1992
ABSTRACT We have analyzed the development in vitro of individual precursor cells from the presumptive truncal segmental ectoderm of the Drosophila embryo to study the intrinsic component in the determination of cell fate. For each cultured cell, the original position within as well as the developmental stage of the donor embryo were known. Cells removed from the ventral neurogenic region develop neural clones. Cells from the dorsal ectoderm and from the dorsalmost part of the ventral neurogenic ectoderm develop epidermal clones. These two classes of clones differ with respect to their division pattern, adhesiveness, cell morphologies and the expression of cell-specific markers. Mixed neural…
Molecular markers for identified neuroblasts in the developing brain of Drosophila.
2003
The Drosophila brain develops from the procephalic neurogenic region of the ectoderm. About 100 neural precursor cells (neuroblasts) delaminate from this region on either side in a reproducible spatiotemporal pattern. We provide neuroblast maps from different stages of the early embryo (stages 9, 10 and 11, when the entire population of neuroblasts has formed), in which about 40 molecular markers representing the expression patterns of 34 different genes are linked to individual neuroblasts. In particular, we present a detailed description of the spatiotemporal patterns of expression in the procephalic neuroectoderm and in the neuroblast layer of the gap genes empty spiracles, hunchback, hu…