We discovered that GPx4-deficient cell death induces an ferrous iron-independent lipid oxidation mediated novel cell death, named lipoxytosis, and have identified the novel cell death executor Lipo genes by screening genome-wide shRNA library and several lipoxytosis chemical inducers and inhibitors by chemical compound library. Thus, it is becoming clear that lipid oxidation-dependent cell death regulated by GPx4 and vitamin E involves at least two distinct pathways: an iron dependent ferroptosis and an iron-independence lipoxytosis. By distinguishing between different disease states going forward, it will become possible to select new treatment options.

Glutathione peroxidase 4 (GPX4) is a key enzyme that reduces phospholipid hydroperoxides and thereby protects membrane lipids from oxidative damage, establishing it as a central regulator of ferroptosis. However, whether other peroxidases contribute to ferroptosis protection has remained unclear. We found that cells lacking GPX4 still retain substantial phospholipid hydroperoxide-reducing capacity, suggesting the existence of additional enzymes. Focusing on peroxiredoxin 6 (PRDX6), previously reported to possess such activity, we evaluated its peroxidase function. Although PRDX6 displayed detectable activity, it was markedly weaker than that of GPX4. Strikingly, PRDX6 knockout significantly increased ferroptosis sensitivity in cancer cells. Mechanistic studies revealed that beyond its peroxidase function, PRDX6 acts as a selenium-acceptor protein, facilitating intracellular selenium handling and enhancing efficient selenium incorporation into selenoproteins, including GPX4. This role was confirmed in vivo, as Prdx6-deficient mouse brains exhibited reduced GPX4 expression and PRDX6-deficient tumor xenografts displayed increased ferroptosis sensitivity. Collectively, these findings identify PRDX6 as a critical determinant of ferroptosis sensitivity, not primarily through peroxidase activity, but via its role as a selenium-handling protein that sustains selenoprotein biosynthesis.

Conjugated fatty acids (CFAs) are known for their anti-tumor activity, yet their underlying mechanisms remain unclear. Here, we identify CFAs as inducers of glutathione peroxidase 4 (GPX4) degradation via chaperone-mediated autophagy (CMA). CFAs such as α-eleostearic acid (α-ESA) promoted GPX4 degradation, mitochondrial reactive oxygen species (ROS) generation, lipid peroxidation, and ultimately ferroptosis in cancer cell lines, including HT1080 and A549. These effects were suppressed by either genetic deletion of LAMP2A, an essential CMA component, or scavenging mitochondrial ROS. Oral administration of an α-ESA-rich oil suppressed xenograft tumor growth of wild-type, but not LAMP2A-deficient, HT1080 cells, concomitant with increased lipid peroxidation, GPX4 degradation, and cell death. Our findings identify mitochondria as the primary target of CFAs to induce lipid peroxidation and GPX4 degradation, offering insight into ferroptosis-based cancer therapy.

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, plays a critical role in liver diseases such as ischemia-reperfusion injury, drug-induced liver failure, and steatohepatitis. We recently identified 7-dehydrocholesterol reductase (DHCR7) as a novel regulator of hepatic ferroptosis through genome-wide CRISPR screening. Loss or inhibition of DHCR7 leads to intracellular accumulation of its substrate, 7-dehydrocholesterol (7-DHC), which exhibits strong radical-trapping activity. 7-DHC sacrificially reacts with lipid radicals, thereby protecting polyunsaturated phospholipids from peroxidation and suppressing ferroptosis. In vitro, DHCR7 inhibition or exogenous 7-DHC addition reduced ferroptotic cell death, while in vivo, Dhcr7 deficiency or pharmacologic blockade ameliorated liver injury in mouse models of hepatic ischemia-reperfusion and acetaminophen toxicity. These findings establish the DHCR7/7-DHC axis as a liver-specific regulatory pathway of ferroptosis, conferring protection to normal hepatocytes yet potentially promoting resistance in cancer cells. This context-dependent dual effect may provide a foundation for disease-tailored therapeutic strategies.

Ferroptosis is an iron-dependent form of regulated cell death characterized by excessive lipid peroxidation, and has been implicated in various human diseases and organ pathologies. However, assessment of lipid peroxidation has required invasive tissue sampling, rendering the noninvasive detection of ferroptosis in humans highly challenging.

In this study, we employed oxidative volatolomics to comprehensively analyze the volatile oxidized lipids (VOLs) generated during ferroptosis. VOLs derived from polyunsaturated fatty acids were produced through iron-dependent lipid peroxidation and released extracellularly as ferroptosis progressed. These VOLs were specifically generated during hepatic ferroptosis in mouse models of acetaminophen-induced liver injury and metabolic dysfunction-associated steatohepatitis metabolic dysfunction-associated steatohepatitis (MASH), and were further detectable in the exhaled breath of patients with MASH. Specific VOLs released via iron-dependent lipid peroxidation may serve as in vivo indicators of ferroptosis and hold promise as breath biomarkers for noninvasive monitoring of cellular health in humans.