| 1. |
- Schleiermacher, G., et al.
(författare)
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Emergence of New ALK Mutations at Relapse of Neuroblastoma
- 2014
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Ingår i: Journal of Clinical Oncology. - : American Society of Clinical Oncology (ASCO). - 0732-183X .- 1527-7755. ; 32:25, s. 2727-2734
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Tidskriftsartikel (refereegranskat)abstract
- Purpose In neuroblastoma, the ALK receptor tyrosine kinase is activated by point mutations. We investigated the potential role of ALK mutations in neuroblastoma clonal evolution. We analyzed ALK mutations in 54 paired diagnosis-relapse neuroblastoma samples using Sanger sequencing. When an ALK mutation was observed in one paired sample, a minor mutated component in the other sample was searched for by more than 100,000 x deep sequencing of the relevant hotspot, with a sensitivity of 0.17%. All nine ALK-mutated cases at diagnosis demonstrated the same mutation at relapse, in one case in only one of several relapse nodules. In five additional cases, the mutation seemed to be relapse specific, four of which were investigated by deep sequencing. In two cases, no mutation evidence was observed at diagnosis. In one case, the mutation was present at a subclonal level (0.798%) at diagnosis, whereas in another case, two different mutations resulting in identical amino acid changes were detected, one only at diagnosis and the other only at relapse. Further evidence of clonal evolution of ALK-mutated cells was provided by establishment of a fully ALK-mutated cell line from a primary sample with an ALK-mutated cell population at subclonal level (6.6%). In neuroblastoma, subclonal ALK mutations can be present at diagnosis with subsequent clonal expansion at relapse. Given the potential of ALK-targeted therapy, the significant spatiotemporal variation of ALK mutations is of utmost importance, highlighting the potential of deep sequencing for detection of subclonal mutations with a sensitivity 100-fold that of Sanger sequencing and the importance of serial samplings for therapeutic decisions.
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| 2. |
- Sriha, J, et al.
(författare)
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BET and CDK Inhibition Reveal Differences in the Proliferation Control of Sympathetic Ganglion Neuroblasts and Adrenal Chromaffin Cells
- 2022
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 14:11
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma arising from the adrenal differ from ganglionic neuroblastoma both genetically and clinically, with adrenal tumors being associated with a more severe prognosis. The different tumor properties may be linked to specific tumor founder cells in adrenal and sympathetic ganglia. To address this question, we first set up cultures of mouse sympathetic neuroblasts and adrenal chromaffin cells. These cultures were then treated with various proliferation inhibitors to identify lineage-specific responses. We show that neuroblast and chromaffin cell proliferation was affected by WNT, ALK, IGF1, and PRC2/EZH2 signaling inhibitors to a similar extent. However, differential effects were observed in response to bromodomain and extraterminal (BET) protein inhibitors (JQ1, GSK1324726A) and to the CDK-7 inhibitor THZ1, with BET inhibitors preferentially affecting chromaffin cells, and THZ1 preferentially affecting neuroblasts. The differential dependence of chromaffin cells and neuroblasts on BET and CDK signaling may indicate different mechanisms during tumor initiation in sympathetic ganglia and adrenal.
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| 3. |
- Mazot, P, et al.
(författare)
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The constitutive activity of the ALK mutated at positions F1174 or R1275 impairs receptor trafficking
- 2011
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 30, s. 2017-2025
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Tidskriftsartikel (refereegranskat)abstract
- Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK), which is transiently expressed during development of the central and peripheral nervous system. ALK has been recently identified as a major neuroblastoma predisposition gene and activating mutations have also been identified in a subset of sporadic neuroblastoma tumors. Two hot spots of ALK mutations have been observed at positions F1174 and R1275. Here, we studied stably transfected cell lines expressing wild-type or F1174L- or R1275Q-mutated ALK in parallel with a neuroblastoma cell line (CLB-GE) in which the allele mutated at position F1174 is amplified. We observed that the mutated ALK variants were essentially intracellular and were largely retained in the reticulum/Golgi compartments. This localization was corroborated by a defect of N-linked glycosylation. Although the mutated receptors exhibited a constitutive activation, the minor pool of receptor addressed to the plasma membrane was much more tyrosine phosphorylated than the intracellular pool. The use of antagonist monoclonal antibodies suggested that the constitutive activity of the mutated receptors did not require the dimerization of the receptor, whereas adequate dimerization triggered by agonist monoclonal antibodies increased this activity. Finally, kinase inactivation of the mutated receptors restored maturation and cell-surface localization. Our results show that constitutive activation of ALK results in its impaired maturation and intracellular retention. Furthermore, they provide a rationale for the potential use of kinase inhibitors and antibodies in ALK-dependent tumors.Oncogene advance online publication, 17 January 2011; doi:10.1038/onc.2010.595.
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| 4. |
- Mestdagh, P., et al.
(författare)
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An integrative genomics screen uncovers ncRNA T-UCR functions in neuroblastoma tumours
- 2010
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 1476-5594 .- 0950-9232. ; 29:24, s. 3583-3592
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Tidskriftsartikel (refereegranskat)abstract
- Different classes of non-coding RNAs, including microRNAs, have recently been implicated in the process of tumourigenesis. In this study, we examined the expression and putative functions of a novel class of non-coding RNAs known as transcribed ultraconserved regions (T-UCRs) in neuroblastoma. Genome-wide expression pro. ling revealed correlations between specific T-UCR expression levels and important clinicogenetic parameters such as MYCN amplification status. A functional genomics approach based on the integration of multi-level transcriptome data was adapted to gain insights into T-UCR functions. Assignments of T-UCRs to cellular processes such as TP53 response, differentiation and proliferation were verified using various cellular model systems. For the first time, our results de. ne a T-UCR expression landscape in neuroblastoma and suggest widespread T-UCR involvement in diverse cellular processes that are deregulated in the process of tumourigenesis. Oncogene (2010) 29, 3583-3592; doi:10.1038/onc.2010.106; published online 12 April 2010
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