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Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma()
Glioblastoma (GBM) is one of the most aggressive and lethal types of brain tumor. Despite the advancements in conventional or targeted therapies, median survival of GBM patients is less than 12 months. Amongst various signaling pathways aberrantly activated in glioma, active Wnt/β-catenin signaling...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Neoplasia Press
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288984/ https://www.ncbi.nlm.nih.gov/pubmed/30530053 http://dx.doi.org/10.1016/j.neo.2018.11.005 |
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author | Khan, Mohsina Muzumdar, Dattatraya Shiras, Anjali |
author_facet | Khan, Mohsina Muzumdar, Dattatraya Shiras, Anjali |
author_sort | Khan, Mohsina |
collection | PubMed |
description | Glioblastoma (GBM) is one of the most aggressive and lethal types of brain tumor. Despite the advancements in conventional or targeted therapies, median survival of GBM patients is less than 12 months. Amongst various signaling pathways aberrantly activated in glioma, active Wnt/β-catenin signaling pathway is one of the crucial oncogenic players. β-catenin, an important mediator of Wnt signaling pathway, gets phosphorylated by GSK3β complex. Phosphorylated β-catenin is specifically recognized by β-Trcp1, a F-box/WD40-repeat protein and with the help of Skp1 it plays a central role in recruiting phosphorylated β-catenin for degradation. In GBM, expression of β-TrCP1 and its affinity for β catenin is reported to be very low. Hence, we investigated whether any other members of the E3 ubiquitin ligase family could be involved in degradation of nuclear β-catenin. We here report that FBXO16, a component of SCF E3 ubiquitin ligase complex, is an interacting protein partner for β-catenin and mediates its degradation. Next, we show that FBXO16 functions as a tumor suppressor in GBM. Under normal growth conditions, FBXO16 proteasomally degrades β-catenin in a GSK-3β independent manner. Specifically, the C-terminal region of FBXO16 targets the nuclear β-catenin for degradation and inhibits TCF4/LEF1 dependent Wnt signaling pathway. The nuclear fraction of β-catenin undergoes K-48 linked poly-ubiquitination in presence of FBXO16. In summary, we show that due to low expression of FBXO16, the β-catenin is not targeted in glioma cells leading to its nuclear accumulation resulting in active Wnt signaling. Activated Wnt signaling potentiates the glioma cells toward a highly proliferative and malignant state. |
format | Online Article Text |
id | pubmed-6288984 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Neoplasia Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-62889842018-12-19 Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma() Khan, Mohsina Muzumdar, Dattatraya Shiras, Anjali Neoplasia Original article Glioblastoma (GBM) is one of the most aggressive and lethal types of brain tumor. Despite the advancements in conventional or targeted therapies, median survival of GBM patients is less than 12 months. Amongst various signaling pathways aberrantly activated in glioma, active Wnt/β-catenin signaling pathway is one of the crucial oncogenic players. β-catenin, an important mediator of Wnt signaling pathway, gets phosphorylated by GSK3β complex. Phosphorylated β-catenin is specifically recognized by β-Trcp1, a F-box/WD40-repeat protein and with the help of Skp1 it plays a central role in recruiting phosphorylated β-catenin for degradation. In GBM, expression of β-TrCP1 and its affinity for β catenin is reported to be very low. Hence, we investigated whether any other members of the E3 ubiquitin ligase family could be involved in degradation of nuclear β-catenin. We here report that FBXO16, a component of SCF E3 ubiquitin ligase complex, is an interacting protein partner for β-catenin and mediates its degradation. Next, we show that FBXO16 functions as a tumor suppressor in GBM. Under normal growth conditions, FBXO16 proteasomally degrades β-catenin in a GSK-3β independent manner. Specifically, the C-terminal region of FBXO16 targets the nuclear β-catenin for degradation and inhibits TCF4/LEF1 dependent Wnt signaling pathway. The nuclear fraction of β-catenin undergoes K-48 linked poly-ubiquitination in presence of FBXO16. In summary, we show that due to low expression of FBXO16, the β-catenin is not targeted in glioma cells leading to its nuclear accumulation resulting in active Wnt signaling. Activated Wnt signaling potentiates the glioma cells toward a highly proliferative and malignant state. Neoplasia Press 2018-12-05 /pmc/articles/PMC6288984/ /pubmed/30530053 http://dx.doi.org/10.1016/j.neo.2018.11.005 Text en © 2018 The Authors http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
spellingShingle | Original article Khan, Mohsina Muzumdar, Dattatraya Shiras, Anjali Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma() |
title | Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma() |
title_full | Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma() |
title_fullStr | Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma() |
title_full_unstemmed | Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma() |
title_short | Attenuation of Tumor Suppressive Function of FBXO16 Ubiquitin Ligase Activates Wnt Signaling In Glioblastoma() |
title_sort | attenuation of tumor suppressive function of fbxo16 ubiquitin ligase activates wnt signaling in glioblastoma() |
topic | Original article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288984/ https://www.ncbi.nlm.nih.gov/pubmed/30530053 http://dx.doi.org/10.1016/j.neo.2018.11.005 |
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