WEE1 stabilizes MYC to promote therapeutic resistance in esophageal adenocarcinoma.

Esophageal adenocarcinoma (EAC) is an aggressive malignancy with poor patient outcomes and limited therapeutic options. WEE1, a G2/M checkpoint kinase, is often upregulated in cancers and associated with resistance to therapy. In this study, we identify a previously unrecognized cytoplasmic role of WEE1 in stabilizing the oncogenic transcription factor MYC and promoting drug resistance in EAC. WEE1 was found to be aberrantly overexpressed and mislocalized to the cytoplasm in EAC cell lines and patient samples. WEE1 depletion or inhibition by MK-1775 significantly reduced MYC protein levels and transcriptional activity by promoting proteasome-mediated degradation. Mechanistically, WEE1 inhibition activated GSK3β, leading to phosphorylation of MYC at threonine 58 and subsequent ubiquitin-dependent degradation. In contrast, overexpression of wild-type WEE1, but not a kinase-dead mutant (K328A), increased p-CDC2 (Y15) and MYC protein levels, confirming that WEE1's kinase activity is essential for maintaining MYC stability. WEE1 inhibition also downregulated the MYC-ABCC1 axis, decreased MRP1 expression, and impaired drug efflux. A high-throughput screen of 892 FDA-approved compounds identified the histone deacetylase inhibitor Panobinostat as a potent synergistic partner of MK-1775. Combination treatment induced robust apoptosis and markedly suppressed tumor growth in EAC organoids and patient-derived xenograft models. These findings reveal a novel cytoplasmic function of WEE1 in sustaining MYC stability and chemoresistance. Targeting WEE1 destabilizes MYC and enhances therapeutic response, supporting the combination of MK-1775 and Panobinostat as a promising treatment strategy for EAC.