Pharmacological targeting and characterization of Voltage-Gated Sodium Channels (VGSCs) expressed in the high-grade glioma microenvironment

High-grade glioma (HGG) cells reactivate neurodevelopmental programs regulated by ion channels to drive tumor progression. The activity of voltage-gated sodium channels (VGSCs) is fundamental to development, a target of blood-brain barrier (BBB)-permeable FDA-approved drugs, and aids tumor advancement in several cancers. However, the contribution of VGSC activity to HGG pathology remains unknown. Using single-cell and spatial transcriptomics, proteomics, and immunohistochemistry, we profiled the expression landscape of the VGSC family in patient tumors from two HGGs: adult glioblastoma and pediatric diffuse midline glioma (DMG). We further validated VGSC expression and function in HGG patient-derived cell lines using RNA, protein, and electrophysiological analyses, and assessed the anticancer efficacy of VGSC-modulating drugs in vitro through cell viability and invasion assays. VGSCs α subunits targeted by different classes of VGSC-drugs are differentially expressed within DMG and glioblastoma. Overall, VGSCs that are sensitive to the neurotoxin, tetrodotoxin (TTX), and in normal physiology are expressed in the nervous system were upregulated by invasive HGG cells at the leading edge of DMG and glioblastoma tumors. Whereas the TTX-insensitive cardiac VGSC NaV1.5 was distinctly more abundant within the cellular tumor of the DMG microenvironment. VGSC-expressing HGG cells within both microenvironments receive oncogenic glutamatergic inputs from surrounding neurons. RNA, protein and electrophysiological analysis of patient-derived HGG cells supported our in vivo findings, where NaV1.5 plays a significant role in DMG cell lines, conducting TTX-insensitive transient and persistent sodium currents. Overall, VGSC-targeting drugs had limited anticancer efficacy; however, GS967 a persistent current blocker, significantly inhibited the invasiveness of a DMG cell line by ~ 33%. Inhibiting intrinsic VGSC persistent currents suppresses invasiveness in DMG subpopulations and may further hinder HGG progression by buffering oncogenic depolarizations from neuron-glioma synaptic activity. Therefore, VGSC-drugs targeting persistent sodium currents offer untapped therapeutic options for treating HGG.