Ether phospholipids are required for mitochondrial reactive oxygen species homeostasis

Mitochondria are hubs where bioenergetics, redox homeostasis, and anabolic metabolism pathways integrate through a tightly coordinated flux of metabolites. The contributions of mitochondrial metabolism to tumor growth and therapy resistance are evident, but drugs targeting mitochondrial metabolism have repeatedly failed in the clinic. Our study in pancreatic ductal adenocarcinoma (PDAC) finds that cellular and mitochondrial lipid composition influence cancer cell sensitivity to pharmacological inhibition of electron transport chain complex I. Profiling of patient-derived PDAC models revealed that monounsaturated fatty acids (MUFAs) and MUFA-linked ether phospholipids play a critical role in maintaining ROS homeostasis. We show that ether phospholipids support mitochondrial supercomplex assembly and ROS production; accordingly, blocking de novo ether phospholipid biosynthesis sensitized PDAC cells to complex I inhibition by inducing mitochondrial ROS and lipid peroxidation. These data identify ether phospholipids as a regulator of mitochondrial redox control that contributes to the sensitivity of PDAC cells to complex I inhibition. Cancer cells can be dependent on mitochondrial respiration to survive. Here, in pancreatic cancer cells, the authors show that monounsaturated fatty acids-linked ether lipids maintain mitochondrial redox homeostasis and modulate sensitivity to inhibition to electron transport chain complex I.

Automated summary

In pancreatic ductal adenocarcinoma, the lipid composition of cancer cells and mitochondria affects sensitivity to pharmacological inhibition of electron transport chain complex I, with ether phospholipids playing a critical role in maintaining ROS homeostasis.