Abstract Paediatric high-grade gliomas (pHGGs) are aggressive brain tumours with dismal prognosis and limited therapeutic options1,2 . Unlike adult gliomas, pHGGs arise during active brain development when neurogenesis is extensive and neural progenitor cells (NPCs) maintain high proliferative capacity3 . Spatial transcriptome analysis from our preliminary data detected sparse NPC marker expression (NESTIN, SOX2) throughout tumour-free paediatric brain samples. In adults, glioblastomas located near the subventricular zone—an NPC-enriched niche—are associated with worse outcomes4,5 . However, the functional contribution of NPC-tumour interactions in paediatric cases remains unexplored, representing a critical knowledge gap. We investigated the effects of NPC-derived signalling on patient-derived pHGG cultures using NPC-conditioned medium, which significantly enhanced tumour proliferation across multiple subtypes. Secretome profiling revealed that G34R mutant tumours uniquely secreted neural stem cell markers (FABP7, ALDH1A1), axonal growth factors (GAP43, PTN), and synaptic scaffolding proteins (CASK, CTNND1), establishing a multi-lineage developmental niche absent in normal astrocytes. RNA sequencing demonstrated subtype-specific transcriptional responses to NPC exposure: G34R tumours underwent neuralization, upregulating neuronal markers (TUBB3, NeuN, SYP) and synaptic remodelling genes (NRXN1/3, SYNDIG1, ADCYAP1), with enrichment of forebrain development and axonogenesis pathways, whereas K27M tumours primarily activated proliferative programs. Functional assays confirmed that NPCs enhance G34R tumour proliferation while simultaneously inducing neuronal differentiation, indicating a neuralization phenotype rather than nonspecific growth promotion. To assess direct cell–cell interactions, we established a dual-labelled tumour–NPC co-culture organoid system, which revealed reciprocal Ki67 activation in both tumour cells and NPCs. Consistently, secretome analysis confirmed that G34R tumours secrete stemness proteins (FABP7, ALDH1A1) and growth factors (PTN, PDGFA), supporting tumour-driven NPC proliferation. Together, these findings provide the first evidence of bidirectional NPC–pHGG interactions mediated by both paracrine signalling and direct contact in the paediatric brain. Subtype-specific reactivation of developmental programs reveals distinct mechanisms driving pHGG progression and highlights novel therapeutic vulnerabilities. 1. Mackay, A., et al. Integrated Molecular Meta-Analysis of 1,000 Pediatric High-Grade and Diffuse Intrinsic Pontine Glioma. Cancer Cell 32, 520-537 e525 (2017). 2. Jones, C. & Baker, S.J. Unique genetic and epigenetic mechanisms driving paediatric diffuse high-grade glioma. Nat Rev Cancer 14(2014). 3. Sanai, N., et al. Corridors of migrating neurons in the human brain and their decline during infancy. Nature 478, 382-386 (2011). 4. Lim, D.A., et al. Relationship of glioblastoma multiforme to neural stem cell regions predicts invasive and multifocal tumor phenotype. Neuro Oncol 9, 424-429 (2007). 5. Jafri, N.F., Clarke, J.L., Weinberg, V., Barani, I.J. & Cha, S. Relationship of glioblastoma multiforme to the subventricular zone is associated with survival. Neuro Oncol 15, 91-96 (2013).
Lee et al. (Tue,) studied this question.