Abstract
<title>Abstract</title> <p> Patient-derived organoids (PDOs) model glioblastoma (GBM), but how isolation from the native microenvironment reshapes malignant cell states remains poorly understood. After re-analyzing public single-cell RNA sequencing datasets of paired primary GBM tissue and derived organoids, we found that <italic>in vitro</italic> microenvironmental deprivation drives a convergent mesenchymal phenotypic collapse, triggered by loss of stromal paracrine signaling. Using consensus non-negative matrix factorization (cNMF), we identified a compensatory "neuronal mimicry" response: isolated GBM cells broadly upregulate neurogenesis program. Functional co-culture experiments showed that peripheral immune cells fail to rescue the native transcriptomic state, but direct physical contact with neurons triggers targeted synaptic rewiring. This contact-dependent neuronal mimicry is concentrated in the neural progenitor-like 2 (NPC2) subtype and involves a structural-to-functional receptor switch. Clinical validation in the TCGA-GBM cohort confirmed that the neuronal mimicry network is conserved and co-regulated <italic>in vivo</italic> , and that the neurogenesis program carries significant adverse prognostic impact. These findings identify NPC2-driven, contact-dependent neuronal mimicry as a survival strategy in GBM and indicate that organoid models in the future should incorporate microenvironmental reconstitution. </p>