USP49 promotes adenocarcinoma of the esophagogastric junction malignant progression via activating SHCBP1-β-catenin-GPX4 axis.

Adenocarcinoma of the esophagogastric junction (AEG) has received widespread attention because of its increasing incidence. However, the molecular mechanism underlying tumor progression remains unclear. Here, we report that the downregulation of Ubiquitin-specific peptidase 49 (USP49) promotes ferroptosis in OE33 and OE19 cells, thereby inhibiting cell proliferation in vitro and in vivo, whereas the overexpression of USP49 had the opposite effect. In addition, USP49 downregulation promoted AEG cell radiotherapy sensitivity. Moreover, overexpression of Glutathione PeroXidase 4 (GPX4) reversed the ferroptosis and proliferation inhibition induced by USP49 knockdown. Mechanistically, USP49 deubiquitinates and stabilizes Shc SH2-domain binding protein 1 (SHCBP1), subsequently facilitating the entry of β-catenin into the nucleus to enhance GPX4 transcriptional expression. Finally, high USP49 expression was correlated with shorter overall survival in patients with AEG. In summary, our findings identify USP49 as a novel regulator of ferroptosis in AEG cells, indicating that USP49 may be a potential therapeutic target in AEG.