1. An iron-dependent metabolic vulnerability underlies VPS34-dependence in RKO cancer cells.
- Author
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Kobylarz MJ, Goodwin JM, Kang ZB, Annand JW, Hevi S, O'Mahony E, McAllister G, Reece-Hoyes J, Wang Q, Alford J, Russ C, Lindeman A, Beibel M, Roma G, Carbone W, Knehr J, Loureiro J, Antczak C, Wiederschain D, Murphy LO, Menon S, and Nyfeler B
- Subjects
- Cell Hypoxia, Cell Line, Tumor, Cell Proliferation, Cholesterol biosynthesis, Cholesterol genetics, Class III Phosphatidylinositol 3-Kinases genetics, Endosomes metabolism, HEK293 Cells, Humans, Lysosomes metabolism, Receptors, LDL metabolism, Transferrin metabolism, rab GTP-Binding Proteins genetics, rab GTP-Binding Proteins metabolism, rab7 GTP-Binding Proteins, Class III Phosphatidylinositol 3-Kinases metabolism, Iron metabolism, Neoplasms metabolism
- Abstract
VPS34 is a key regulator of endomembrane dynamics and cargo trafficking, and is essential in cultured cell lines and in mice. To better characterize the role of VPS34 in cell growth, we performed unbiased cell line profiling studies with the selective VPS34 inhibitor PIK-III and identified RKO as a VPS34-dependent cellular model. Pooled CRISPR screen in the presence of PIK-III revealed endolysosomal genes as genetic suppressors. Dissecting VPS34-dependent alterations with transcriptional profiling, we found the induction of hypoxia response and cholesterol biosynthesis as key signatures. Mechanistically, acute VPS34 inhibition enhanced lysosomal degradation of transferrin and low-density lipoprotein receptors leading to impaired iron and cholesterol uptake. Excess soluble iron, but not cholesterol, was sufficient to partially rescue the effects of VPS34 inhibition on mitochondrial respiration and cell growth, indicating that iron limitation is the primary driver of VPS34-dependency in RKO cells. Loss of RAB7A, an endolysosomal marker and top suppressor in our genetic screen, blocked transferrin receptor degradation, restored iron homeostasis and reversed the growth defect as well as metabolic alterations due to VPS34 inhibition. Altogether, our findings suggest that impaired iron mobilization via the VPS34-RAB7A axis drive VPS34-dependence in certain cancer cells., Competing Interests: The authors are, at present, or were during the time of their contribution to this manuscript, employed by Novartis Pharma AG. As such, the authors received salaries and own stock in Novartis as part of their remuneration for employment. There are no competing interests as regards consultancies, patents or products in development or currently marketed. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.
- Published
- 2020
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