Abstract Brain cells such as neural precursor cells (NPCs) migrate through highly confined interstitial spaces during brain development/maintenance, imposing significant mechanical stress on the cell and nucleus. NPCs have been proposed as potential cells of origin for gliomas, including GBM, linking developmental migratory programs to disease-relevant cellular states. Nuclear envelope rupture (NER) has been observed during cancer cell confined migration (CM) in vitro; however, most studies examining nuclear mechanobiology are conducted under ambient oxygen conditions. We hypothesized that, compared with normoxia (21% O2), the lower physiologic oxygen tension of the brain microenvironment (5% O2, brainoxia) would decrease nuclear stiffness, increase CM compliance, decrease envelope integrity–associated phenotypes, maintain confinement-induced DNA damage, and enhance cell survival during restricted NPC migration. hNPCs were subjected to CM using custom PDMS microfluidic devices that recapitulate in vivo–like interstitial constraints, with unconfined controls. Experiments were performed under normoxia or brainoxia. Confocal imaging of cells expressing a nuclear localization sequence (NLS) –GFP was used to monitor migratory behavior and nuclear dynamics. DNA double-strand break–associated damage was evaluated by fluorescence microscopy through detection of 53BP1–mCherry foci. Post-migration viability and neurosphere-forming capacity were assessed to evaluate survival and clonogenic potential. Nuclear mechanical properties were examined using STED–based morphometrics and Brillouin microscopy, and nuclear lamina protein composition was evaluated by immunoblotting. NPCs exposed to CM exhibited altered nuclear dynamics and reduced overall survival relative to unconfined controls. Brainoxia was associated with reduced baseline nuclear stiffness and altered mechanical adaptation following confinement. Despite reduced survival under mechanical confinement, surviving NPCs exhibited increased clonogenic capacity, forming larger and more rapidly expanding neurospheres when normalized to equal viable post-migration cell numbers. These phenotypic changes were accompanied by oxygen-dependent decreases in lamin A/C protein via WB. Ongoing analyses are assessing how brainoxia influences nuclear envelope rupture frequency, DNA damage (53BP1-mcherry foci), and migration dynamics (constriction transit time and traversal fraction) under confinement, and how these features relate to post-migratory clonogenic potential. Together, these findings indicate that confined migration imposes a selective pressure on NPC populations and that physiologic brain oxygen tension modulates nuclear mechanical state and post-migratory clonogenic behavior. Given that NPCs are proposed cells of origin for gliomas, including glioblastoma, these results suggest that brain-relevant mechanical and oxygen conditions may shape early stress adaptation programs relevant to gliomagenesis. Citation Format: Hassan Saadi, Siddharth Shah, Yogeshwari Ambekar, Maggie Elpers, Jeffrey A. Winkles, Jan Lammerding, Giuliano Scarcelli, Eli E. Bar, Graeme Woodworth. Effect of confined migration on nuclear mechanics and envelope integrity of neural precursor cells under physiologic brain oxygen tension abstract. In: Proceedings of the AACR Special Conference in Cancer Research: Brain Cancer; 2026 Mar 23-25; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2026;86 (6Suppl): Abstract nr B045.
Saadi et al. (Mon,) studied this question.