The production of bioactive lipids by phospholipases has long been appreciated as an important mode of cellular communication. Phospholipase D (PLD) enzymes hydrolyze phosphatidylcholine to generate a choline headgroup and the important lipid second messenger, phosphatidic acid (PtdOH). PLD family members are found in a diverse range of species from viruses to humans and regulate many important physiological processes including cytoskeletal rearrangements, cell migration, immune response, and cell proliferation. As such, PLD promotes oncogenic processes and elevated PLD activity has been documented in many types of cancerous tissue and derived cell lines. PLD activity is associated with cell cycle progression, resistance to apoptotic stimuli, and tumor cell invasion, but the molecular mechanisms of these PLD-mediated processes are largely uncharacterized. The goal of this project was to identify and characterize novel PLD-protein complexes in order to further understand the mechanisms by which PLD promotes cancer growth and survival. In this dissertation, PLD-derived PtdOH is demonstrated to be a novel regulator of pro-survival Akt kinase in glioblastoma cells by regulating membrane recruitment and activation of Akt. Inhibition of PLD enzymatic activity and subsequent Akt activation decreases GBM cell viability by specifically inhibiting autophagic flux. Additionally, PLD is shown to interact with a number of metabolic enzymes and a potential role for the regulation of cellular bioenergetics in GBM is explored. The results of this research provide mechanistic insight into PLD-mediated cancer cell survival.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-01142014-193543 |
| Date | 11 February 2014 |
| Creators | Bruntz, Ronald Chase |
| Contributors | Brian E. Wadzinski, Daniel C. Liebler, John H. Exton, H. Alex Brown, Heidi E. Hamm, Kevin C. Ess |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-01142014-193543/ |
| Rights | restrictone, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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