Wisp1 Is An Overexpressed Driver of Glioblastoma

<p>Despite current multimodal therapies for glioblastoma (GBM) the prognosis remains very grim. There is a tremendous need to identify new genetic drivers which can serve as potential therapeutic targets. In order to find new drivers, we leveraged genomic datasets to conduct a context specific <em>in vivo</em> functional genomic screen of overexpressed and/or amplified genes in GBM. We identified WISP1, a secreted extracellular matrix protein, to be an overexpressed driver in GBM. Overexpression of WISP1 was able to drive tumor growth in various <em>in vivo</em> models. Knockdown of WISP1 with shRNAs resulted in reduced colony formation <em>in vitro</em> and reduced tumor growth <em>in vivo</em>. Rescue experiments validated that the shRNAs were on target. Functional characterization of the protein revealed that the TSP module is necessary for the phenotype. Intriguingly, overexpression of WISP1 lacking the signal peptide module for secretion resulted in a strong phenotype. Co-culture and conditioned medium experiments further supported a secretion independent intracellular role of WISP1 in GBM. Though WISP1 is a secreted protein we have found some localization in the cytosol. Overall, we have revealed WISP1 to be a driver of GBM with possible therapeutic potential as a target. This study has resulted in a paradigm shift in our current understanding of WISP1 as merely a secreted extracellular matrix protein as we have shown here that it can drive GBM in a non-canonical manner in the cytosol.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation (PhD)

Year dc:date.available

2017

Authors dc:creator

• Dasgupta, Pushan R
• <p>0000-0002-1999-8494</p>

Contributors dc:contributor

• Giulio F. Draetta, M.D., Ph.D.
• Russell Broaddus, M.D., Ph.D.
• Sadhan Majumder, Ph.D.

• functional genomics
• oncogene
• glioblastoma
• driver
• gain-of-function screen
• Cancer Biology
• Medicine and Health Sciences
• Molecular Genetics

Repository record dc:identifier

https://digitalcommons.library.tmc.edu/utgsbs_dissertations/780

OAI identifier oai:identifier

oai:digitalcommons.library.tmc.edu:utgsbs_dissertations-1822