Defining a Water-Soluble Formulation of Arachidonic Acid as a Novel Ferroptosis Inducer in Cancer Cells

• Published in: Biomolecules (Basel, Switzerland) Vol. 14; no. 5; p. 555
• Main Authors: Day, Zoe I, Mayfosh, Alyce J, Baxter, Amy A, Williams, Scott A, Hildebrand, Joanne M, Rau, Thomas F, Poon, Ivan K H, Hulett, Mark D
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04.05.2024
• Subjects: Antioxidants; Apoptosis; Arachidonic acid; Arachidonic Acid - metabolism; Arachidonic Acid - pharmacology; Cancer; Cancer cells; Caspase-3; Cell death; Cell Line, Tumor; Cytotoxicity; Fatty acids; Ferroptosis; Ferroptosis - drug effects; Humans; Kinases; L-lysine; Lipid Droplets - drug effects; Lipid Droplets - metabolism; Lipid peroxidation; Lipid Peroxidation - drug effects; Lipids; Lymphoma; Lysine; Microscopy; Necroptosis; Neoplasms - drug therapy; Neoplasms - genetics; Neoplasms - metabolism; Neoplasms - pathology; Oncology, Experimental; Physiological aspects; Protein transport; Solubility; Water - chemistry; Australia; United Kingdom > UK; United States > US; Germany; arachidonic acid; cancer; ferroptosis; cell death; fatty acids; L-lysine
• ISSN: 2218-273X; 2218-273X
• DOI: 10.3390/biom14050555

Here, we describe GS-9, a novel water-soluble fatty acid-based formulation comprising L-lysine and arachidonic acid, that we have shown to induce ferroptosis. GS-9 forms vesicle-like structures in solution and mediates lipid peroxidation, as evidenced by increased C11-BODIPY fluorescence and an accumulation of toxic malondialdehyde, a downstream product of lipid peroxidation. Ferroptosis inhibitors counteracted GS-9-induced cell death, whereas caspase 3 and 7 or MLKL knock-out cell lines are resistant to GS-9-induced cell death, eliminating other cell death processes such as apoptosis and necroptosis as the mechanism of action of GS-9. We also demonstrate that through their role of sequestering fatty acids, lipid droplets play a protective role against GS-9-induced ferroptosis, as inhibition of lipid droplet biogenesis enhanced GS-9 cytotoxicity. In addition, Fatty Acid Transport Protein 2 was implicated in GS-9 uptake. Overall, this study identifies and characterises the mechanism of GS-9 as a ferroptosis inducer. This formulation of arachidonic acid offers a novel tool for investigating and manipulating ferroptosis in various cellular and anti-cancer contexts.