Discovery of novel benzylaniline derivatives containing chloroacetamide as GPX4 inhibitors with potential efficacy in triple-negative breast cancer

Abstract

Studies have found that induction of ferroptosis in tumors may become a new treatment method. Glutathione peroxidase 4 (GPX4) has become a promising target for cancer treatment by inducing ferroptosis, of which covalent GPX4 inhibitors are the most widely studied class so far. A series of GPX4 inhibitors containing chloroacetyl warheads were designed and synthesized, and the antiproliferative activity was evaluated using six tumor cell lines. Among them, compound Y19 showed strong anti-proliferative activity with high ferroptosis selectivity against MDA-MB-231 cells with IC₅₀ value of 21 nM. Moreover, Y19 effectively inhibited GPX4 activity and molecular docking revealed that Y19 may covalently bind to Sec 46 site of GPX4. In addition, compound Y19 caused intracellular Fe²⁺ accumulation, leading to increased levels of lipid peroxides (LPOs) and induction of ferroptosis. This was followed by the discovery that Y19 induced ferroptosis by LPOs and reactive oxygen species (ROS) production leading to DNA damage. In vivo pharmacodynamic evaluation demonstrated that Y19 exhibited superior antitumor efficacy compared to RSL3 at an equivalent dose, achieving a tumor growth inhibition (TGI) rate of 72.53 % at 10 mg/kg in the MDA-MB-231 xenograft model, with no significant toxicity observed. This provides structurally diverse tool compounds to reveal the basic biology of GPX4 as well as to explore potential efficacy with the treatment of cancer by inducing ferroptosis.