SPATIALLY RESTRICTED IMMATURE NEURONAL PROGRAMS DRIVE FUNCTIONAL CONNECTIVITY IN GLIOBLASTOMA

Glioblastoma (GB) is one of the most lethal human cancers that uniquely integrates into functional neural circuits of the human brain. Rather than passively inhabiting the neural microenvironment, GB forms synaptic and electrical interactions with surrounding neurons that promote tumor progression and therapy resistance. The neuronal states and circuit mechanisms enabling this integration, however, remain poorly defined.
To address this, we integrated patient-derived neuroimaging (MEG and resting-state fMRI), spatially resolved biopsies, single-cell and spatial transcriptomics, multi-electrode array recordings, whole-cell electrophysiology, Ca-imaging, retrograde tracing and pharmacological perturbation using human patient samples and a GB-injected human organotypic slice model.
Across modalities, we identify a spatially restricted peritumoral neuronal niche that preferentially supports GB integration and is enriched in projection-capable neurons. Connectivity hotspots localize to FLAIR-abnormal tumor margins and exhibit hallmarks of neuronal immaturity, including synaptogenic transcriptional programs, altered dendritic spine architecture, and hyperexcitable electrophysiological properties.
Neurons within these niches regress to a developmentally immature state and show elevated expression of the chloride importer NKCC1 and its upstream WNK–SPAK signaling pathway resulting in a significant decrease of inhibitory neuronal input caused by functional switch of GABAergic signaling. Pharmacological inhibition of NKCC1 in GB-injected human organotypic slices suppresses tumoral calcium wave propagation, reduces tumor cell proliferation, and limits tumor integration into neural circuits, consistent with restoration of inhibitory GABAergic control.
Together, these findings demonstrate that GB interacts with the neuronal microenvironment through spatially confined connectivity hotspots o enable functional integration into human brain circuits, revealing targetable neurophysiological vulnerabilities at the tumor–neuron interface.