Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
Graduate Program in Chemical Biology, University of Michigan, Ann Arbor, MI, USA.
Nat Commun. 2021 Aug 11;12(1):4860. doi: 10.1038/s41467-021-24859-2.
Cancer metabolism is rewired to support cell survival in response to intrinsic and environmental stressors. Identification of strategies to target these adaptions is an area of active research. We previously described a cytosolic aspartate aminotransaminase (GOT1)-driven pathway in pancreatic cancer used to maintain redox balance. Here, we sought to identify metabolic dependencies following GOT1 inhibition to exploit this feature of pancreatic cancer and to provide additional insight into regulation of redox metabolism. Using pharmacological methods, we identify cysteine, glutathione, and lipid antioxidant function as metabolic vulnerabilities following GOT1 withdrawal. We demonstrate that targeting any of these pathways triggers ferroptosis, an oxidative, iron-dependent form of cell death, in GOT1 knockdown cells. Mechanistically, we reveal that GOT1 inhibition represses mitochondrial metabolism and promotes a catabolic state. Consequently, we find that this enhances labile iron availability through autophagy, which potentiates the activity of ferroptotic stimuli. Overall, our study identifies a biochemical connection between GOT1, iron regulation, and ferroptosis.
癌症代谢被重新布线,以响应内在和环境应激源来支持细胞存活。鉴定针对这些适应的策略是一个活跃的研究领域。我们之前描述了胰腺癌细胞中胞质天冬氨酸氨基转移酶(GOT1)驱动的途径,用于维持氧化还原平衡。在这里,我们试图确定 GOT1 抑制后的代谢依赖性,以利用这一胰腺癌特征,并为氧化还原代谢的调节提供更多的见解。我们使用药理学方法确定,在 GOT1 缺失后,半胱氨酸、谷胱甘肽和脂质抗氧化功能是代谢上的脆弱性。我们证明,靶向这些途径中的任何一个都会在 GOT1 敲低细胞中触发铁死亡,这是一种氧化的、依赖铁的细胞死亡形式。从机制上讲,我们揭示了 GOT1 抑制抑制线粒体代谢并促进分解代谢状态。因此,我们发现这通过自噬增强了不稳定铁的可用性,从而增强了铁死亡刺激物的活性。总的来说,我们的研究确定了 GOT1、铁调节和铁死亡之间的生化联系。