ZDHHC2‐Dependent Palmitoylation Dictates Ferroptosis and Castration Sensitivity in Prostate Cancer via Controlling ACSL4 Degradation and Lipid Peroxidation

Ferroptosis represents a promising vulnerability to overcome therapeutic resistance in castration-resistant prostate cancer (CRPC). While S-palmitoylation of lipid peroxide-scavenging proteins such as GPX4 and SLC7A11 has been shown to suppress ferroptosis, whether palmitoylation modulates the lipid peroxidation generation remains unclear. Here, we identified the palmitoyltransferase ZDHHC2 as a critical driver of enzalutamide resistance through destabilizing ACSL4. ZDHHC2 is transcriptionally upregulated by a FOXA1/CXXC5/TET2 complex and promotes S-palmitoylation of the deubiquitinase USP19, which impairs its interaction with ACSL4. This disrupts USP19-mediated ACSL4 stabilization, promoting its ubiquitin-proteasome degradation and consequently suppressing lipid peroxidation and ferroptosis. We synthesized a small-molecule ZDHHC2 inhibitor, TTZ1, which restores ACSL4 protein, reactivates ferroptosis, and reverses enzalutamide resistance in CRPC cell lines and patient-derived xenograft models. This study uncovers a previously unrecognized mechanism by which palmitoylation regulates ferroptosis through modulating ACSL4 stability, and highlights the ZDHHC2-USP19-ACSL4 axis as a druggable target for overcoming resistance in advanced prostate cancer.