Arachidonic acid induces ferroptosis in hepatocellular carcinoma via the SIRT5-ACSL4/LPCAT3/ALOX15 axis, leading to lipid peroxidation and mitochondrial dysfunction.

[BACKGROUND] Hepatocellular carcinoma (HCC) is among the most common and lethal malignancies worldwide, characterized by profound metabolic reprogramming and poor prognosis. Ferroptosis, an iron-dependent death driven by lipid peroxidation, has recently gained attention in cancer biology. Arachidonic acid (AA), an ω-6 polyunsaturated fatty acid and key membrane phospholipid, regulates lipid remodeling and redox balance, but its role in HCC ferroptosis remains unclear.

[OBJECTIVE] To investigate AA-induced ferroptosis in HCC and elucidate the involvement of the SIRT5-ACSL4/LPCAT3/ALOX15 pathway METHODS: Human (SK-HEP-1) and murine (Hepa1-6) HCC cells were exposed to AA, and viability, proliferation, invasion, and ferroptosis markers were assessed using standard assays and probes. Mitochondrial function was evaluated by membrane potential, staining, and electron microscopy. Molecular docking, dynamics simulation, and non-targeted metabolomics, analyzed AA-protein/lipid interactions, validated by interaction assays and a SIRT5 inhibitor. An in vivo xenograft model confirmed the findings.

[RESULTS] AA suppressed proliferation and invasion and induced ferroptosis, with increased Fe²⁺, reactive oxygen species, malondialdehyde, decreased glutathione, and downregulation of GPX4/xCT. AA also upregulated SIRT5, ACSL4, LPCAT3, and ALOX15. Computational docking and dynamics indicated stable AA-protein interactions, validated by interaction assays and SIRT5 inhibition. Metabolomics revealed elevated PE species and oxidized AA derivatives, indicating ferroptosis. In vivo, AA reduced tumor growth and enhanced lipid peroxidation and iron accumulation.

[CONCLUSION] AA induces ferroptosis in HCC through the SIRT5-ACSL4/LPCAT3/ALOX15 pathway, offering mechanistic insight into lipid metabolism-related ferroptotic regulation.