Role of the voltage-gated sodium channel Nav1.6 in glioma and candidate drugs screening

Gliomas remain a clinical challenge, common and fatal. Treatment of glioblastoma remains elusive, and researchers have focused on discovering new mechanisms and drugs. It has been well established that the expression of voltage-gated sodium channels (VGSCs) is abnormally increased in numerous malignancies and, in general, is rarely expressed in the corresponding normal tissues. This suggests that ion channel activity appears to be associated with malignant progression of tumors. VGSCs remain largely unknown as to how their activity leads to an increase in cancer cell activity or invasiveness. Certain sodium ion channel subtypes (for instance, Nav1.5 and Nav1.7) are associated with metastasis and invasion in cancers including breast and colorectal cancers. A previous study by the authors explored the expression of certain ion channels in glioma, but there are few studies related to Nav1.6. The current study aimed to elucidate the expression and role of Nav1.6 in glioma and to screen potential drugs for the treatment of glioma by virtual screening and drug sensitivity analysis. Nav1.6 relative expression of mRNA and protein was determined by reverse transcription-quantitative PCR and western blot analysis. Cell proliferation was determined by Cell Counting Kit-8 assay. Cell migration was assessed by cellular wound healing assay. Cell invasion and apoptosis were detected by Transwell cell invasion assay and flow cytometry. Last but not least, FDA-approved drugs were screened using virtual screening, molecular docking and NCI-60 drug sensitivity analyses based on the expression and structure of Nav1.6. In glioma cells, Nav1.6 was significantly upregulated and expressed mostly in the cytoplasm and cell membrane; its expression was positively correlated with pathological grade. A172 and U251 cells exhibited reduced proliferation, migration and invasion when Nav1.6 expression was knocked down, and apoptosis was increased. TNF-a (100 pg/ml) acting on glioma cells was found to upregulate the expression level of Nav1.6, and TNF-a was involved in the process of Nav1.6 promoting malignant progression of glioma. Finally, certain FDA-approved drugs were identified by virtual screening and drug sensitivity analysis. In conclusion, the present study demonstrated the expression and role of Nav1.6 in glioma and identified several FDA-approved drugs that are highly correlated with Nav1.6 and could be candidate drugs for patients with glioma.