Depressive effectiveness of vigabatrin (γ-vinyl-GABA), an antiepileptic drug, in intermediate-conductance calcium-activated potassium channels in human glioma cells

Abstract

Background: Vigabatrin (VGB) is an approved non-traditional antiepileptic drug that has been revealed to have potential for treating brain tumors; however, its effect on ionic channels in glioma cells remains largely unclear. Methods: With the aid of patch-clamp technology, we investigated the effects of VGB on various ionic currents in the glioblastoma multiforme cell line 13–06-MG. Results: In cell-attached configuration, VGB concentration-dependently reduced the activity of intermediate-conductance Ca2+-activated K+ (IKCa) channels, while DCEBIO (5,6-dichloro-1-ethyl-1,3-dihydro-2H-benzimidazol-2-one) counteracted the VGB-induced inhibition of IKCa channels. However, the activity of neither large-conductance Ca2+-activated (BKCa) nor inwardly rectifying K+ (KIR) channels were affected by the presence of VGB in human 13–06-MG cells. However, in the continued presence of VGB, the addition of GAL-021 or BaCl2 effectively suppressed BKCa and KIR channels. Conclusions: The inhibitory effect of VGB on IKCa channels demonstrated in the current study could be an important underlying mechanism of VGB-induced antineoplastic (e.g., anti-glioma) actions.