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YB-1 is elevated in medulloblastoma and drives proliferation in Sonic hedgehog - dependent cerebellar granule neuron progenitor cells and medulloblastoma cells

Post-natal proliferation of cerebellar granule neuron precursors (CGNPs), proposed cells-of-origin for the SHH-associated subgroup of medulloblastoma (MB), is driven by Sonic Hedgehog (Shh) and Insulin-like Growth Factor (IGF) in the developing cerebellum. Shh induces the oncogene Yes-associated pro...

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Detalles Bibliográficos
Autores principales: Dey, Abhinav, Robitaille, Mélanie, Remke, Marc, Maier, Caroline, Malhotra, Anshu, Gregorieff, Alex, Wrana, Jeffrey L, Taylor, Michael D, Angers, Stéphane, Kenney, Anna Marie
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931992/
https://www.ncbi.nlm.nih.gov/pubmed/26725322
http://dx.doi.org/10.1038/onc.2015.491
Descripción
Sumario:Post-natal proliferation of cerebellar granule neuron precursors (CGNPs), proposed cells-of-origin for the SHH-associated subgroup of medulloblastoma (MB), is driven by Sonic Hedgehog (Shh) and Insulin-like Growth Factor (IGF) in the developing cerebellum. Shh induces the oncogene Yes-associated protein (YAP), which drives IGF2 expression in CGNPs and mouse Shh-associated medulloblastomas. To determine how IGF2 expression is regulated downstream of YAP, we carried out an unbiased screen for transcriptional regulators bound to IGF2 promoters. We report that Y-box binding protein-1 (YB-1), an onco-protein regulating transcription and translation, binds to IGF2 promoter P3. We observed that YB-1 is up-regulated across human medulloblastoma subclasses as well as in other varieties of pediatric brain tumors. Utilizing the cerebellar progenitor model for the Shh-subgroup of MB in mice, we show for the first time that YB-1 is induced by Shh in CGNPs. Its expression is YAP-dependent and it is required for IGF2 expression in CGNPs. Finally, both gain-of function and loss-of-function experiments reveal that YB-1 activity is required for sustaining CGNP and medulloblastoma cell (MBC) proliferation. Collectively, our findings describe a novel role for YB-1 in driving proliferation in the developing cerebellum and medulloblastoma cells and they identify the SHH:YAP:YB1:IGF2 axis as a powerful target for therapeutic intervention in medulloblastomas.