Copper/iron bimetal phenolic networks boosted apoptosis/ferroptosis/cuproptosis combined tumor therapy through dual glutathione depletion

Abstract

Cuproptosis, ferroptosis, and reactive oxygen species (ROS)-involved apoptosis are all bound by the overexpressed glutathione (GSH) in tumor microenvironment (TME). Herein, a dual GSH depletor is developed based on copper/iron bimetal gallic acid phenolic networks (CuFeGA MPNs) for combination tumor therapy by GSH depletion boosted apoptosis/ferroptosis/cuproptosis simultaneously. The CuFeGA MPNs are dissociated following exposure to the highly expressed GSH, causing the release of large quantities of GA, Fe2+, and Cu+. The released GA then further consumes the residual GSH. In conjunction with the GSH response-consumption behavior, the GSH depletion is achieved by those dual GSH consumption procedures. Subsequently, the expression of glutathione peroxides 4 (GPX4) is down-regulated by GSH depletion for further accumulation of lipid peroxides (LPO). Moreover, intracellular ROS levels are improved via Fenton reaction with released Cu+ and Fe2+, leading to buildup of LPO concurrently. Eventually, excess ROS can activate mitochondria-associated apoptosis, and the surge of LPO initiates ferroptosis without GSH homeostasis. Meanwhile, the oligomerization of lipoylated dihydrolipoamide S-acetyltransferase (DLAT) and decline of iron-sulfur cluster protein are induced by excessive Cu+ in the absence of GSH chelation, activating cuproptosis. This work provides a feasible approach for the realization of multiple mechanisms combined tumor therapy.