Glioblastoma (GBM) remains the most common primary brain tumor with a median survival of 12–18 months, underscoring the need for new therapeutic targets. The authors report that the channel-forming glycoprotein PANX1 is upregulated in GBM relative to normal brain tissue and is expressed across patient tumors. Western blot analysis of multiple patient-derived GBM cell lines demonstrated significantly higher PANX1 protein levels compared with brain tissue and control glial cells, indicating consistent overexpression in primary tumor-derived models.
To investigate the role of PANX1 in GBM biology, the investigators generated PANX1 knockout (PANX1-KO) GBM cells using CRISPR/Cas9. Bulk RNA-sequencing was performed to compare gene expression profiles between PANX1-KO and control GBM cells. Gene Ontology and KEGG pathway analyses showed that PANX1 deletion affected genes encoding cell surface and cell junction components and altered multiple cellular processes and pathways.
Among the pathways highlighted by pathway analyses were the HIPPO signaling pathway and components of the Wnt pathway. Notably, PANX1-KO cells showed critical downregulation of β-catenin mRNA along with other Wnt-related transcripts, suggesting transcriptional effects linking PANX1 status to major oncogenic signaling cascades.
At the protein level, deletion of PANX1 disrupted β-catenin. Functionally, PANX1-KO GBM cells exhibited a dramatic reduction in migratory capacity and a marked decrease in cell growth relative to control cells. These observations indicate that loss of PANX1 impairs cellular behaviors associated with tumor aggressiveness and that such effects are accompanied by changes in pathways known to regulate proliferation and motility.
The study evaluated two pharmacological PANX1 blockers, Probenecid (PBN) and Spironolactone (SPIR), in patient-derived GBM cells. Treatment with either PBN or SPIR significantly reduced the number of live cells and impaired migration in scratch assays compared with untreated controls. These pharmacologic findings mirror several of the phenotypes observed after genetic deletion, supporting the functional relevance of PANX1 channel activity to GBM cell survival and motility.
Both pharmacologic inhibitors produced marked decreases in F-actin filament formation, indicating effects on the cytoskeleton that likely contribute to reduced migration. In addition, β-catenin cellular localization shifted with treatment: compared with controls, β-catenin appeared more intracellular following PANX1 blockade. These morphological and subcellular localization changes provide mechanistic context linking PANX1 activity to cytoskeletal organization and Wnt/β-catenin signaling dynamics.
In xenografted GBM models, treatment with Probenecid (PBN) led to a reduction in tumor cell viability as assessed by bioluminescent imaging. The authors also observed a reduced incidence of hemorrhaging within treated tumors. These in vivo observations extend the in vitro findings, showing that pharmacologic PANX1 inhibition can diminish tumor viability and may influence tumor-associated vascular or hemorrhagic features in xenograft settings.
Collectively, the data indicate that PANX1 contributes to GBM tumorigenic properties through effects on the HIPPO and Wnt signaling pathways, cytoskeletal organization, and cellular localization of β-catenin. Both genetic deletion and pharmacologic inhibition reduced cell growth and migration and produced measurable effects in xenografts, supporting further evaluation of PANX1 as a candidate therapeutic target in GBM.
The source reports these findings without detailing dose regimens, specific cell line identities beyond being patient-derived, or the full set of quantitative data and statistical analyses in this summary. Likewise, mechanistic links between PANX1 channel activity and the downstream transcriptional and protein changes are described by association; further studies would be required to establish direct causative steps and to examine safety and efficacy in clinical contexts.
Funding sources for the work included the Canadian Institutes of Health Research and several cancer research organizations. The authors declared no competing interests.
Overall, these results support continued investigation of PANX1 inhibition as a potential therapeutic approach in glioblastoma, particularly given its impact on β-catenin, Wnt, and HIPPO pathway components and on tumor cell behavior both in vitro and in vivo.