| 1. |
- Lamers, Fieke, et al.
(författare)
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Targeted BCL2 inhibition effectively inhibits neuroblastoma tumour growth
- 2012
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 1879-0852 .- 0959-8049. ; 48:16, s. 3093-3103
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Tidskriftsartikel (refereegranskat)abstract
- Genomic aberrations of key regulators of the apoptotic pathway have hardly been identified in neuroblastoma. We detected high BCL2 mRNA and protein levels in the majority of neuroblastoma tumours by Affymetrix expression profiling and Tissue Micro Array analysis. This BCL2 mRNA expression is strongly elevated compared to normal tissues and other malignancies. Most neuroblastoma cell lines lack this high BCL2 expression. Only two neuroblastoma cell lines (KCNR and SJNB12) show BCL2 expression levels representative for neuroblastoma tumours. To validate BCL2 as a therapeutic target in neuroblastoma we employed lentivirally mediated shRNA. Silencing of BCL2 in KCNR and SJNB12 resulted in massive apoptosis, while cell lines with low BCL2 expression were insensitive. Identical results were obtained by treatment of the neuroblastoma cell lines with the small molecule BCL2 inhibitor ABT263, which is currently being clinically evaluated. Combination assays of ABT263 with most classical cytostatics showed strong synergistic responses. Subcutaneous xenografts of a neuroblastoma cell line with high BCL2 expression in NMRI nu/nu mice showed a strong response to ABT263. These findings establish BCL2 as a promising drug target in neuroblastoma and warrant further evaluation of ABT263 and other BCL2 inhibiting drugs. (C) 2012 Elsevier Ltd. All rights reserved.
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| 2. |
- Molenaar, Jan J., et al.
(författare)
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Sequencing of neuroblastoma identifies chromothripsis and defects in neuritogenesis genes
- 2012
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 483:7391, s. 107-589
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastomais a childhood tumour of the peripheral sympathetic nervous system. The pathogenesis has for a long time been quite enigmatic, as only very few gene defects were identified in this often lethal tumour(1). Frequently detected gene alterations are limited to MYCN amplification (20%) and ALK activations (7%)(2-5). Here we present a whole-genome sequence analysis of 87 neuroblastoma of all stages. Few recurrent amino-acid-changing mutations were found. In contrast, analysis of structural defects identified a local shredding of chromosomes, known as chromothripsis, in 18% of high-stage neuroblastoma(6). These tumours are associated with a poor outcome. Structural alterations recurrently affected ODZ3, PTPRD and CSMD1, which are involved in neuronal growth cone stabilization(7-9). In addition, ATRX, TIAM1 and a series of regulators of the Rac/Rho pathway were mutated, further implicating defects in neuritogenesis in neuroblastoma. Most tumours with defects in these genes were aggressive high-stage neuroblastomas, but did not carry MYCN amplifications. The genomic landscape of neuroblastoma therefore reveals two novel molecular defects, chromothripsis and neuritogenesis gene alterations, which frequently occur in high-risk tumours.
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| 3. |
- De Brouwer, Sara, et al.
(författare)
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Meta-analysis of neuroblastomas reveals a skewed ALK mutation spectrum in tumors with MYCN amplification.
- 2010
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Ingår i: Clinical cancer research : an official journal of the American Association for Cancer Research. - 1078-0432 .- 1557-3265. ; 16:17, s. 4353-62
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Tidskriftsartikel (refereegranskat)abstract
- Activating mutations of the anaplastic lymphoma kinase (ALK) were recently described in neuroblastoma. We carried out a meta-analysis of 709 neuroblastoma tumors to determine their frequency and mutation spectrum in relation to genomic and clinical parameters, and studied the prognostic significance of ALK copy number and expression.
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| 4. |
- Lamers, Fieke, et al.
(författare)
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Identification of BIRC6 as a novel intervention target for neuroblastoma therapy
- 2012
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neuroblastoma are pediatric tumors of the sympathetic nervous system with a poor prognosis. Apoptosis is often deregulated in cancer cells, but only a few defects in apoptotic routes have been identified in neuroblastoma. Methods: Here we investigated genomic aberrations affecting genes of the intrinsic apoptotic pathway in neuroblastoma. We analyzed DNA profiling data (CGH and SNP arrays) and mRNA expression data of 31 genes of the intrinsic apoptotic pathway in a dataset of 88 neuroblastoma tumors using the R2 bioinformatic platform (http://r2.amc.nl). BIRC6 was selected for further analysis as a tumor driving gene. Knockdown experiments were performed using BIRC6 lentiviral shRNA and phenotype responses were analyzed by Western blot and MTT-assays. In addition, DIABLO levels and interactions were investigated with immunofluorescence and co-immunoprecipitation. Results: We observed frequent gain of the BIRC6 gene on chromosome 2, which resulted in increased mRNA expression. BIRC6 is an inhibitor of apoptosis protein (IAP), that can bind and degrade the cytoplasmic fraction of the pro-apoptotic protein DIABLO. DIABLO mRNA expression was exceptionally high in neuroblastoma but the protein was only detected in the mitochondria. Upon silencing of BIRC6 by shRNA, DIABLO protein levels increased and cells went into apoptosis. Co-immunoprecipitation confirmed direct interaction between DIABLO and BIRC6 in neuroblastoma cell lines. Conclusion: Our findings indicate that BIRC6 may have a potential oncogenic role in neuroblastoma by inactivating cytoplasmic DIABLO. BIRC6 inhibition may therefore provide a means for therapeutic intervention in neuroblastoma.
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| 5. |
- Molenaar, Jan J., et al.
(författare)
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Copy Number Defects of G1-Cell Cycle Genes in Neuroblastoma are Frequent and Correlate with High Expression of E2F Target Genes and a Poor Prognosis
- 2012
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257. ; 51:1, s. 10-19
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Tidskriftsartikel (refereegranskat)abstract
- The tightly controlled network of cell cycle genes consists of a core of cyclin dependent kinases (CDKs) that are activated by periodically expressed cyclins. The activity of the cyclin-CDK complexes is regulated by cyclin dependent kinase inhibitors (CDKIs) and multiple signal transduction routes that converge on the cell cycle. Neuroblastoma are pediatric tumors that belong to the group of small round blue cell tumors, characterized by a fast proliferation. Here, we present high throughput analyses of cell cycle regulating genes in neuroblastoma. We analyzed a series of 82 neuroblastomas by comparative genomic hybridization arrays, single nucleotide polymorphism arrays, and Affymetrix expression arrays and analyzed the datasets in parallel with the R2 bioinformatic tool (http://r2.amc.nl). About 30% of the tumors had genomic amplifications, gains, or losses with shortest regions of overlap that suggested implication of a series of G1 cell cycle regulating genes. CCND1 (cyclin D1) and CDK4 were amplified or gained and the chromosomal regions containing the CDKN2 (INK4) group of CDKIs were frequently deleted. Cluster analysis showed that tumors with genomic aberrations in G1 regulating genes over-expressed E2F target genes, which regulate S and G2/M phase progression. These tumors have a poor prognosis. Our findings suggest that pharmacological inhibition of cell cycle genes might bear therapeutic promises for patients with high risk neuroblastoma. (C) 2011 Wiley Periodicals, Inc.
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