Abstract
Our research uncovers a role for ATR in responding to ECM stiffness and promoting epithelial-to-mesenchymal transition (EMT) and metastasis. ATR, when deubiquitinated and upregulated by USP21 under enhanced ECM stiffness conditions, phosphorylates the nuclear protein SUN2, which promotes β-catenin nuclear translocation and EMT. ATM-mediated EMT promotes polymorphonuclear myeloid-derived suppressor cell recruitment and inhibits CD103+ dendritic cells, fostering an immunosuppressive tumor milieu. ATR inhibition disrupts this malignant cascade by promoting mesenchymal-to-epithelial transition to enhance antitumor immunity and mitigate metastases. Consistently, circulating HLA-DR+ dendritic cells were also enhanced following treatment with the ATR inhibitor berzosertib in patients with therapeutically resistant early-stage breast cancer. Our data suggest that ATR-targeted therapy may be optimized by considering both DNA damage–dependent and EMT-inducing effects of ATR
Authors
Xinyi Tu, Xiangyu Zeng, Yaoliang Sun, Yaobin Ouyang, Lingling Zhu, Ping Yin, Kevin Pavelko, Roberto Leon-Ferre, Yanxia Jiang, Haidong Dong, Jodi Carter, Shouhai Zhu, Jann N. Sarkaria, Liewei Wang, Jinzhou Huang, Kuntian Luo, Yiqun Han, Zheming Wu, Zhenkun Lou, Robert W. Mutter
Graphical abstract
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)