6 results on '"Fell, Stuart M."'
Search Results
2. Combined epigenetic and differentiation-based treatment inhibits neuroblastoma tumor growth and links HIF2α to tumor suppression.
- Author
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Westerlund I, Shi Y, Toskas K, Fell SM, Li S, Surova O, Södersten E, Kogner P, Nyman U, Schlisio S, and Holmberg J
- Subjects
- Animals, Azacitidine therapeutic use, Basic Helix-Loop-Helix Transcription Factors genetics, Basic Helix-Loop-Helix Transcription Factors metabolism, Chemotherapy, Adjuvant, Decitabine, Female, Hypoxia-Inducible Factor 1, alpha Subunit genetics, Hypoxia-Inducible Factor 1, alpha Subunit metabolism, Hypoxia-Inducible Factor 1, alpha Subunit physiology, Mice, Mice, Nude, Azacitidine analogs & derivatives, Basic Helix-Loop-Helix Transcription Factors physiology, Cell Proliferation genetics, Genetic Therapy methods, Neuroblastoma pathology, Tretinoin therapeutic use
- Abstract
Neuroblastoma is a pediatric cancer characterized by variable outcomes ranging from spontaneous regression to life-threatening progression. High-risk neuroblastoma patients receive myeloablative chemotherapy with hematopoietic stem-cell transplant followed by adjuvant retinoid differentiation treatment. However, the overall survival remains low; hence, there is an urgent need for alternative therapeutic approaches. One feature of high-risk neuroblastoma is the high level of DNA methylation of putative tumor suppressors. Combining the reversibility of DNA methylation with the differentiation-promoting activity of retinoic acid (RA) could provide an alternative strategy to treat high-risk neuroblastoma. Here we show that treatment with the DNA-demethylating drug 5-Aza-deoxycytidine (AZA) restores high-risk neuroblastoma sensitivity to RA. Combined systemic distribution of AZA and RA impedes tumor growth and prolongs survival. Genome-wide analysis of treated tumors reveals that this combined treatment rapidly induces a HIF2α-associated hypoxia-like transcriptional response followed by an increase in neuronal gene expression and a decrease in cell-cycle gene expression. A small-molecule inhibitor of HIF2α activity diminishes the tumor response to AZA+RA treatment, indicating that the increase in HIF2α levels is a key component in tumor response to AZA+RA. The link between increased HIF2α levels and inhibited tumor growth is reflected in large neuroblastoma patient datasets. Therein, high levels of HIF2α, but not HIF1α, significantly correlate with expression of neuronal differentiation genes and better prognosis but negatively correlate with key features of high-risk tumors, such as MYCN amplification. Thus, contrary to previous studies, our findings indicate an unanticipated tumor-suppressive role for HIF2α in neuroblastoma., Competing Interests: The authors declare no conflict of interest.
- Published
- 2017
- Full Text
- View/download PDF
3. Neuroblast differentiation during development and in neuroblastoma requires KIF1Bβ-mediated transport of TRKA.
- Author
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Fell SM, Li S, Wallis K, Kock A, Surova O, Rraklli V, Höfig CS, Li W, Mittag J, Henriksson MA, Kenchappa RS, Holmberg J, Kogner P, and Schlisio S
- Subjects
- Animals, Apoptosis genetics, Cell Line, Tumor, Gene Expression Regulation, Developmental, Gene Silencing, Mutation, Neuroblastoma physiopathology, Neurodegenerative Diseases genetics, Neurodegenerative Diseases physiopathology, Neurofibromin 1 genetics, Neurofibromin 1 metabolism, PC12 Cells, Rats, Signal Transduction genetics, Sympathetic Nervous System cytology, ras Proteins genetics, Cell Differentiation genetics, Kinesins genetics, Kinesins metabolism, Neuroblastoma genetics, Neurons cytology, Receptor, trkA metabolism
- Abstract
We recently identified pathogenic KIF1B β mutations in sympathetic nervous system malignancies that are defective in developmental apoptosis. Here we deleted KIF1B β in the mouse sympathetic nervous system and observed impaired sympathetic nervous function and misexpression of genes required for sympathoadrenal lineage differentiation. We discovered that KIF1Bβ is required for nerve growth factor (NGF)-dependent neuronal differentiation through anterograde transport of the NGF receptor TRKA. Moreover, pathogenic KIF1B β mutations identified in neuroblastoma impair TRKA transport. Expression of neuronal differentiation markers is ablated in both KIF1B β-deficient mouse neuroblasts and human neuroblastomas that lack KIF1Bβ. Transcriptomic analyses show that unfavorable neuroblastomas resemble mouse sympathetic neuroblasts lacking KIF1Bβ independent of MYCN amplification and the loss of genes neighboring KIF1B on chromosome 1p36. Thus, defective precursor cell differentiation, a common trait of aggressive childhood malignancies, is a pathogenic effect of KIF1Bβ loss in neuroblastomas. Furthermore, neuropathy-associated KIF1Bβ mutations impede cargo transport, providing a direct link between neuroblastomas and neurodegeneration., (© 2017 Fell et al.; Published by Cold Spring Harbor Laboratory Press.)
- Published
- 2017
- Full Text
- View/download PDF
4. RNA helicase A is a downstream mediator of KIF1Bβ tumor-suppressor function in neuroblastoma.
- Author
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Chen ZX, Wallis K, Fell SM, Sobrado VR, Hemmer MC, Ramsköld D, Hellman U, Sandberg R, Kenchappa RS, Martinson T, Johnsen JI, Kogner P, and Schlisio S
- Subjects
- Animals, Apoptosis, Cell Nucleus metabolism, Chromosomes, Human, Pair 1, DEAD-box RNA Helicases genetics, Humans, Karyopherins metabolism, Kinesins genetics, Mice, Mice, Inbred C57BL, Neoplasm Proteins genetics, PC12 Cells, Rats, Sequence Deletion, Sympathetic Nervous System metabolism, Tumor Cells, Cultured, DEAD-box RNA Helicases metabolism, Kinesins metabolism, Neoplasm Proteins metabolism, Nerve Growth Factor genetics, Neuroblastoma genetics
- Abstract
Unlabelled: Inherited KIF1B loss-of-function mutations in neuroblastomas and pheochromocytomas implicate the kinesin KIF1B as a 1p36.2 tumor suppressor. However, the mechanism of tumor suppression is unknown. We found that KIF1B isoform β (KIF1Bβ) interacts with RNA helicase A (DHX9), causing nuclear accumulation of DHX9, followed by subsequent induction of the proapoptotic XIAP-associated factor 1 (XAF1) and, consequently, apoptosis. Pheochromocytoma and neuroblastoma arise from neural crest progenitors that compete for growth factors such as nerve growth factor (NGF) during development. KIF1Bβ is required for developmental apoptosis induced by competition for NGF. We show that DHX9 is induced by and required for apoptosis stimulated by NGF deprivation. Moreover, neuroblastomas with chromosomal deletion of 1p36 exhibit loss of KIF1Bβ expression and impaired DHX9 nuclear localization, implicating the loss of DHX9 nuclear activity in neuroblastoma pathogenesis., Significance: KIF1Bβ has neuroblastoma tumor-suppressor properties and promotes and requires nuclear-localized DHX9 for its apoptotic function by activating XAF1 expression. Loss of KIF1Bβ alters subcellular localization of DHX9 and diminishes NGF dependence of sympathetic neurons, leading to reduced culling of neural progenitors, and, therefore, might predispose to tumor formation.
- Published
- 2014
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5. The 1p36 Tumor Suppressor KIF 1Bβ Is Required for Calcineurin Activation, Controlling Mitochondrial Fission and Apoptosis.
- Author
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Li, Shuijie, Fell, Stuart M., Surova, Olga, Smedler, Erik, Wallis, Karin, Chen, Zhi Xiong, Hellman, Ulf, Johnsen, John Inge, Martinsson, Tommy, Kenchappa, Rajappa S., Uhlén, Per, Kogner, Per, and Schlisio, Susanne
- Subjects
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CARRIER proteins , *TUMOR suppressor proteins , *CALCINEURIN , *APOPTOSIS , *NEUROBLASTOMA , *MITOCHONDRIAL dynamics , *MITOCHONDRIA , *PROGNOSIS - Abstract
Summary KIF1Bβ is a candidate 1p36 tumor suppressor that regulates apoptosis in the developing sympathetic nervous system. We found that KIF1Bβ activates the Ca 2+ -dependent phosphatase calcineurin (CN) by stabilizing the CN-calmodulin complex, relieving enzymatic autoinhibition and enabling CN substrate recognition. CN is the key mediator of cellular responses to Ca 2+ signals and its deregulation is implicated in cancer, cardiac, neurodegenerative, and immune disease. We show that KIF1Bβ affects mitochondrial dynamics through CN-dependent dephosphorylation of Dynamin-related protein 1 (DRP1), causing mitochondrial fission and apoptosis. Furthermore, KIF1Bβ actuates recognition of all known CN substrates, implying a general mechanism for KIF1Bβ in Ca 2+ signaling and how Ca 2+ -dependent signaling is executed by CN. Pathogenic KIF1Bβ mutations previously identified in neuroblastomas and pheochromocytomas all fail to activate CN or stimulate DRP1 dephosphorylation. Importantly, KIF1Bβ and DRP1 are silenced in 1p36 hemizygous-deleted neuroblastomas, indicating that deregulation of calcineurin and mitochondrial dynamics contributes to high-risk and poor-prognosis neuroblastoma. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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6. REPLY TO MOHLIN ET AL.: High levels of EPAS1 are closely associated with key features of low-risk neuroblastoma.
- Author
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Isabelle Westerlund, Yao Shi, Konstantinos Toskas, Fell, Stuart M., Erik Södersten, Johan Holmberg, Shuijie Li, and Susanne Schlisio
- Subjects
NEUROBLASTOMA ,ENDOTHELIAL cells - Published
- 2017
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- View/download PDF
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