Natural progression of glioma enhances functional connection with the cerebral cortex through synaptogenesis

• Utilization of multifocal glioma patients and mouse glioma models to overcome the lack of longitudinal data in untreated glioma patients. • Larger tumors in multifocal gliomas demonstrate enhanced functional connectivity with the cerebral cortex and higher degree centrality. • Synaptic organization and associated regulatory pathways are progressively activated during the natural progression of glioma. Understanding the progression mechanisms of glioma holds significant implications for improving clinical management. However, the natural progression patterns of glioma remain poorly understood due to the lack of longitudinal clinical samples from untreated patients. In this study, we systematically explored the natural progression trajectory of glioma by combining functional magnetic resonance imaging (fMRI) analysis of 24 rare multifocal glioma patients with bioinformatic analysis of single-cell RNA sequencing (scRNA-seq) data obtained from tumor samples of glioma mouse with early, mid, and endpoint lesions. We discovered that larger tumors in multifocal gliomas exhibit stronger functional connectivity with the cerebral cortex and higher degree centrality within brain networks. ScRNA-seq of longitudinal murine glioma samples revealed progressive activation of synaptic organization and associated regulatory pathways during the natural progression of glioma. Our multimodal, cross-scale study demonstrates that the natural progression pattern of glioma macroscopically manifests as functional hyperconnectivity with the cerebral cortex, which is supported by microscale molecular programs driving synaptic and axonal remodeling. These findings elucidate the characteristics and mechanisms underlying glioma natural progression.