Intracellular Delivery of Glutathione Peroxidase Degrader Induces Ferroptosis In Vivo.

Ferroptosis is a new form of regulated, non-apoptotic cell death driven by iron-dependent phospholipid peroxidation. Its therapeutic potential is however, greatly limited by the low efficiency of regulating cell ferroptosis in vivo. Herein, we report a PROTAC-based protein degrader that depletes endogenous glutathione peroxidase 4 (GPX4) and induces cancer cell ferroptosis. We demonstrate that a rationally designed GPX4 degrader, dGPX4, can deplete tumor cell GPX4 via proteasomal protein degradation, showing a five-fold enhancement of ferroptosis induction efficiency compared to that of GPX4 inhibition using ML162. Moreover, we show that the intracellular delivery of dGPX4 using biodegradable lipid nanoparticles (dGPX4@401-TK-12) induces cell-selective ferroptosis by targeting cancer cell microenvironment. The in vivo administration of dGPX4@401-TK-12 effectively suppresses tumor growth without appreciable side effects. We anticipate the protein degradation strategy described herein could be easily expanded to other essential regulatory proteins of ferroptosis for developing targeted cancer therapeutics.