Targeting aldehyde dehydrogenase ALDH3A1 increases ferroptosis vulnerability in squamous cancer.

Ferroptosis is a unique modality of regulated cell death induced by excessive lipid peroxidation, playing a crucial role in tumor suppression and providing potential therapeutic strategy for cancer treatment. Here, we find that aldehyde dehydrogenase-ALDH3A1 tightly links to ferroptosis in squamous cell carcinomas (SCCs). Functional assays demonstrate the enzymatic activity-dependent regulation of ALDH3A1 in protecting SCC cells against ferroptosis through catalyzing aldehydes and mitigating lipid peroxidation. Furthermore, a specific covalent inhibitor of ALDH3A1-EN40 significantly enhances the ferroptosis sensitivity induced by the ferroptosis inducer. The combination of EN40 and a ferroptosis inducer exhibits a synergistic effect, effectively inhibiting the proliferation of SCC cells/organoids and suppressing tumor growth both in vitro and in vivo. On mechanism, high expression of ALDH3A1 is transcriptionally governed by TP63, which binds to super-enhancer of ALDH3A1. Collectively, our findings reveal a yet-unrecognized function of ALDH3A1 exploited by SCC cells to evade ferroptosis, and targeting ALDH3A1 may enhance the effect of ferroptosis-induced therapy in SCCs.