Tetraethylammonium inhibits glioma cells via increasing production of intracellular reactive oxygen species

Background: Potassium Channel blockers have been shown to possess antitumor properties, but the role of Apoptosis remains to be clarified. In this study, we investigated the antiproliferative effect of tetraethylammonium (TEA), a nonspecific Potassium Channel blocker, in rat C6 and 9L glioma cells.

Methods: Cytotoxicity was evaluated by MTT assay. Apoptosis was detected by TUNEL and annexin V-FITC/propidium iodide assays. Protein levels were determined by Western blot analysis. Intracellular Reactive Oxygen Species (ROS) levels were assessed flow cytometrically.

Results: TEA (2-60 mM) significantly inhibited the proliferation of C6 and 9L glioma cells. In addition, increased cell Apoptosis was confirmed after treatment with 40 mM TEA. Apoptosis was associated with a dramatic increase in ROS levels and altered Bcl-2/Bax protein balance.

Conclusion: TEA can inhibit proliferation and induce Apoptosis in both cell lines; therefore, it might be associated with the increase in intracellular ROS production.