Eag-1 channel blocking inhibits the proliferation of glioma cells

Abstract

Objective To evaluate the influence of Eag-1 channel blocking on bioactivity of glioma cells in vitro. Methods Different small interfering RNAs (siRNAs) targeting for Eag-1 channel were designed and transfected to the U87 cells, and the blocking effects of those siRNAs were further confirmed on mRNA and protein levels by RT-PCR and Western blotting. The 50 nmol/l siRNAs (siRNA1 and siRNA2) and quinidine (5, 10, 20, 30 and 40 mmol/l) were used to block the activity of Eag-1 channel, respectively; and blank control group was also established. The proliferation of U87 cells 24, 48 and 72 h after the treatments was detected by MTT method; the changes of generation cycle,apoptosis ratio and intracellular reactive oxygen species (ROS) concentration were detected by flow cytometry. Results High mRNA and protein levels of Eag-1 channel on glioma cell line U87 were confirmed in the blank control group, however, siRNA1 and siRNA2 transfection groups showed significantly lower mRNA and protein levels of Eag-1 channel on glioma cell line U87. MTT method indicated that, 24, 48 and 72 h after the treatments, the proliferation of U87 cells in the siRNA1 and siRNA2 transfection groups, and quinidine treatment groups (10, 20, 30 and 40 mmol/l) was significantly inhibited as compared with that in the blank control group (P＜0.05). The IC50 value of quinidine is33.7mmol/l. As compared with the blank control group, 50 nmol/L siRNA1 and siRNA2 transfection groups, and 33.7 mmol/l quinidine treatment group enjoyed a significantly increased cell percentage at G1 stage, cell apoptosis ratio and intracellular ROS level (P＜0.05). Conclusion Eag-1 channel blocking can obviously inhibit the proliferation of glioma cells, increase the cell percentage at G1 stage and intracellular ROS level, and induce apoptosis of glioma cells. Key words: Glioma; Eag-1 channel; Small interfering RNA; Quinidine