Notch1 O-GlcNAcylation drives tumor stemness and mechanoadaptation to a stiff microenvironment and promotes chordoma recurrence

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Abstract

Chordoma are rare malignant osseous neoplasms with a striking rate of recurrence. Primary chordomas typically originate from embryonic notochord remnants, whereas recurrent chordomas usually stem from tumor cells infiltrating bone or cartilage post-surgery. Clinically, the recurrent chordomas exhibit stiffer extracellular microenvironment (ECM) than primary tumors. Intriguingly, this study identified cytoskeleton rearrangement, stress fiber reorganization, enhanced stemness, and Notch signaling activation in recurrent chordoma tissues or cell lines surviving stiff substrates, indicating the critical roles of mechanical remodeling and tumor stemness in stiffness-resistance. We propose a novel recurrence model where tumor cells experience mechanoadaptive organization to resist stiff microenvironment-induced cell death. O-GlcNAcylation of Notch1 intracellular domain (NICD1) is central to this process. Mechanistically, the stiff ECM-driven ligand-independent phosphorylation of EPHA2 sequentially activates LYN kinase, and subsequently triggers OGT activity by phosphorylating Y989 and Y418, the newly revealed critical residues for OGT glycosyltransferase activity; this induces NICD1 O-GlcNAcylation at T2063, T2090, and S2162, specifically promoting transcription of mechanical and stemness-related genes. MIR31 deletion upregulates LYN, enhancing stiffness perception and tipping the balance toward O-GlcNAc addition to NICD1, finally resulting in mechanoadaptation- and tumor stemness-driven recurrence. Consequently, MIR31 deletion is a potential biomarker for recurrence and patient stratification in Notch- or OGT-targeted therapies.

Authors

Chengjie Lian, Weiyan Peng, Peiqiang Su, Yan Ye, Jialing Liu, Dongsheng Huang, Xuejuan Sun, Yi Pu, Zhiheng Liao, Xudong Wang, Zhu Qiu, Shanshan Wu, Lei Liu