Potential Oncogenic Role of PRSS1 Identified by Whole Exome Sequencing in Glioma Primary Cell Lines

Background Glioblastoma (GBM) is the most common and aggressive adult primary brain malignancy, with poor survival and marked resistance to therapy. In pediatric patients, diffuse midline gliomas (DMG), including diffuse intrinsic pontine gliomas (DIPG) with H3K27 alterations, are similarly lethal and completely refractory to therapy. These tumors present high inter and intratumoral heterogeneity, driven in part by glioma stemlike cells (GSCs), which compromises therapeutic responses and complicates model development. Whole-exome sequencing (WES) of patient derived GSCs can clarify subtype specific Single Nucleotide Variant (SNV)/Copy Number Variation (CNV) patterns and potentially expose novel vulnerabilities. Methods To identify recurrent molecular patterns and candidate therapeutic targets, we established a cohort of GSCs derived from eight patients, comprising six adult GBM and two pediatric DIPG, including H3 mutant and wild-type subtypes. WES of this cohort was performed to characterize copy number alterations and somatic point mutations. Results Adult-derived GBM IDH-Wild-Type GSCs recapitulated canonical genomic alterations including chromosome 7 duplication, chromosome 10 loss, EGFR amplification, and CDKN2A/B deletion. DIPG derived lines exhibited more heterogeneous genomic profiles, reflecting subtype-specific divergence. Importantly, all cell lines harbored a recurrent nonsense mutation in PRSS1 (p.Gly177*), truncating the catalytic domain. This mutation was also observed in primary GBM samples. Reduced PRSS1 expression correlated with poorer survival in GBM datasets, and we propose a mechanism whereby PRSS1 loss disrupts PAR2 signaling and promotes compensatory PAR1 activation, enhancing tumor progression. Conclusions Our study presents a comprehensive WES analysis of patient-derived GSCs, revealing key genomic alterations across adult and pediatric tumors. We identified a recurrent PRSS1 stop-gain mutation across all cells, suggesting a potential novel oncogenic role in gliomas of the PAR2 protease signaling axis, uncovering a common vulnerability and a potential therapeutic target in high-grade gliomas.