AKR1C3 enhances radioresistance in esophageal adenocarcinoma via inhibiting ferroptosis through suppressing TRIM21-mediated ubiquitination of HSPA5.

Esophageal adenocarcinoma (EAC) is the predominant subtype of esophageal cancer (EC) in high-income countries, and radioresistance is one of the key factors for the poor prognosis. In this study, we successfully established a radioresistant EAC in vitro model. Aldo-keto reductase 1C3 (AKR1C3) was identified as a promising regulator of radioresistance by RNA-seq analysis and subsequent functional studies. Through integrated analyses of scRNA-seq and TCGA datasets, we found that AKR1C3 was likely to enhance radioresistance by inhibition of ferroptosis. Indeed, analysis of the lipid ROS level by C11-Bodipy staining and the result of transmission electron microscopy revealed that AKR1C3 could prevent EAC cells from ferroptosis. Mechanistically, AKR1C3 binds to the nucleotide-binding domain of HSPA5, thereby inhibiting the E3 ligase TRIM21-induced ubiquitin-dependent proteasomal degradation of HSPA5, which further stabilizes GPX4, thus inhibiting ferroptosis. Importantly, AKR1C3 inhibitor resensitized the EAC patient-derived organoids to radiotherapy. In conclusion, this study highlights AKR1C3 as a regulator of radioresistance and a potential therapeutic target in EAC.