Elucidating the role of Perilipin-2-mediated lipid droplet formation in supporting glioblastoma pathogenesis
Hematology, Oncology
Cell Biology
Final Report Abstract
We investigated the effect of PLIN2 knockdown on the sensitivity of glioma cell lines LN229 and LN18 to exogenous oxidative stress, and found that shRNA-mediated stable knockdown of PLIN2 failed to sensitize these cells to H2O2 treatments. In parallel, we discovered that endogenous PLIN2 expression was characteristically low in glioma and glioblastoma cell lines relative to established cancer cell lines of other tumor types or lineages. In delineating the mechanisms by which PLIN2 is overexpressed in tumors, we found that oncogenic RAS signaling activation is associated with PLIN2 and PLIN3 overexpression in pancreatic adenocarcinoma and glioblastoma tumor tissue. Following this, we uncovered in in vitro cell models that oncogenic RAS signaling leads to PLIN2/3 upregulation and that PLIN2 expression is regulated by the transcription factor ATF3. Further, knockdown of PLIN2 and PLIN3, led to sensitization of KRAS-mutant cells to oxidative stress, as well as a decrease in tumorigenic potential, modeled using anchorage-independence assays. Finally, consistent with the reprogramming of lipid metabolism in cancer cell lines, we discovered that oncogenic RAS signaling led to increased resistance to ferroptosis, presumably as a protective mechanism to buffer against susceptibility to lipid peroxidation. We determined that oncogenic RAS signaling drives ferroptosis resistance by co-opting the function of the ferroptosis suppressor, GTP cyclohydrolase I (GCH1). Notably, targeted repression of GCH1 or of the tetrahydrobiopterin (BH4) synthesis pathway, which is mediated by GCH1, was sufficient to sensitize oncogenic RAS transformed cells to ferroptosis in 2D and 3D cell models. Overall, we uncover novel downstream effectors of oncogenic RAS signaling that hold potential for future exploitation as therapeutic targets against human cancers with oncogenic RAS signaling activation including glioblastoma, which constitute particularly aggressive, and difficultto-treat tumors.
Publications
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Proteomic Screens for Suppressors of Anoikis Identify IL1RAP as a Promising Surface Target in Ewing Sarcoma. Cancer Discovery, 11(11), 2884-2903.
Zhang, Hai-Feng; Hughes, Christopher S.; Li, Wei; He, Jian-Zhong; Surdez, Didier; El-Naggar, Amal M.; Cheng, Hongwei; Prudova, Anna; Delaidelli, Alberto; Negri, Gian Luca; Li, Xiaojun; Ørum-Madsen, Maj Sofie; Lizardo, Michael M.; Oo, Htoo Zarni; Colborne, Shane; Shyp, Taras; Scopim-Ribeiro, Renata; Hammond, Colin A.; Dhez, Anne-Chloe ... & Sorensen, Poul H.
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Elevated FSP1 protects KRAS-mutated cells from ferroptosis during tumor initiation. Cell Death & Differentiation, 30(2), 442-456.
Müller, Fabienne; Lim, Jonathan K. M.; Bebber, Christina M.; Seidel, Eric; Tishina, Sofya; Dahlhaus, Alina; Stroh, Jenny; Beck, Julia; Yapici, Fatma Isil; Nakayama, Keiko; Torres, Fernández Lucia; Brägelmann, Johannes; Leprivier, Gabriel & von, Karstedt Silvia
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The eEF2 kinase coordinates the DNA damage response to cisplatin by supporting p53 activation.
Lim, Jonathan KM; Samiei, Arash; Carnie, Christopher J.; Brinkman, Vanessa; Radiloff, Daniel; Cran, Jordan; Leprivier, Gabriel & Sorensen, Poul H.
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Oncogenic RAS signaling is a tumor cell-intrinsic determinant of ferroptosis suppression via induction of the GCH1/BH4 axis.
Lim, Jonathan K. M.; Stölting, Frauke; Roth, Dennis; Ballmeyer, Christian; Tishina, Sofya; Thewes, Leonie; Kalis, Simone; Boussettaoui, Samira; Picard, Daniel; Zhang, Hai-Feng; Lewandowska, Oksana; Reiff, Tobias; Levy, Tal; Rotblat, Barak; Remke, Marc; Sorensen, Poul H.; Brägelmann, Johannes; Beleggia, Filippo; Berndt, Carsten ... & Leprivier, Gabriel
