Discovery of Artesunate (ARS) PROTACs as GPX4 protein degraders for the treatment of bladder cancer

Bladder cancer is the second most prevalent malignancy of the urinary system worldwide, with high incidence and mortality rates. However, existing drugs for bladder cancer treatment often cause numerous adverse reactions. Although artesunate (ARS) exhibits anti-bladder cancer activity, its scope is rather limited and the specific targets remain unclear. Therefore, in this study, the Proteolysis-Targeting Chimera (PROTAC) technology was used to design and synthesize novel ARS derivatives. The antitumor activities of these compounds were evaluated against three human bladder cancer cell lines (T24, RT4, and J82). Of these compounds, A7 exhibited 12-fold stronger antiproliferative activity against bladder cancer cells than ARS. Molecular docking, surface plasmon resonance (SPR), cellular thermal shift assay (CETSA) and western blotting studies demonstrated that A7 directly targeted and degraded glutathione peroxidase 4 (GPX4) protein through the ubiquitin-proteasome system. A7 further induced bladder cancer cell ferroptosis. Furthermore, A7 showed potent tumor suppressive activity in a xenograft T24 nude mouse model. In conclusion, our findings indicate that A7 exerts notable antitumor effects against bladder cancer in vitro and in vivo. This study highlights the tremendous potential of the PROTAC technology in enhancing the efficacy of natural products and identifying therapeutic targets, demonstrating its broad application prospects in the development of natural products-based drugs.