Voltage-gated K+ channel blocker quinidine inhibits proliferation and induces apoptosis by regulating expression of microRNAs in human glioma U87-MG cells
Voltage-gated K+ channel blocker quinidine inhibits proliferation and induces apoptosis by regulating expression of microRNAs in human glioma U87-MG cells
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DOI：
10.3892/ijo.2014.2777
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发表时间：
2015-02-01
影响因子：
5.2
通讯作者：
Li, Chao-Ying
中科院分区：
文献类型：
--
作者：
Ru, Qin;Tian, Xiang;Li, Chao-Ying
越来越多的证据证明钾通道（K+通道）参与调节细胞增殖、细胞周期进程和肿瘤细胞凋亡。然而，确切的细胞机制仍不清楚。在本研究中，我们研究了常用的电压门控K+通道阻滞剂奎尼丁对人胶质瘤U87-MG细胞增殖和凋亡的影响和机制。我们发现奎尼丁显着抑制U87-MG细胞的增殖并以剂量依赖性方式诱导细胞凋亡。 Caspase比色法结果表明线粒体途径是奎尼丁诱导细胞凋亡过程的主要参与方式。此外，电生理检测中奎尼丁抑制电压门控K+通道电流的浓度范围与奎尼丁抑制细胞增殖、诱导细胞凋亡的浓度范围一致。在用奎尼丁 (100 μmol/l) 处理的 U87-MG 细胞中，通过 miRNA 阵列分析检测到，2,042 个人类 microRNA (miRNA) 中有 11 个上调，16 个下调。通过实时定量PCR进一步验证了奎尼丁处理对miR-149-3p的上调和miR-424-5p的下调。此外，使用miRNA靶点预测程序，对两种差异表达的miRNA预测与细胞增殖和凋亡相关的推定靶基因。综上所述，这些数据表明，电压门控 K+ 通道阻断剂奎尼丁在人胶质瘤细胞中的抗增殖和促凋亡作用至少部分是通过调节 miRNA 的表达来介导的，并为电压门控 K+ 通道介导细胞增殖和凋亡的机制提供了进一步的支持。
Accumulating evidence has proved that potassium channels (K+ channels) are involved in regulating cell proliferation, cell cycle progression and apoptosis of tumor cells. However, the precise cellular mechanisms are still unknown. In the present study, we investigated the effect and mechanisms of quinidine, a commonly used voltage-gated K+-channel blocker, on cell proliferation and apoptosis of human glioma U87-MG cells. We found that quinidine significantly inhibited the proliferation of U87-MG cells and induced apoptosis in a dose-dependent manner. The results of caspase colorimetric assay showed that the mitochondrial pathway was the main mode involved in the quinidine-induced apoptotic process. Furthermore, the concentration range of quinidine, which inhibited voltage-gated K+ channel currents in electrophysiological assay, was consistent with that of quinidine inhibiting cell proliferation and inducing cell apoptosis. In U87-MG cells treated with quinidine (100 mu mol/l), 11 of 2,042 human microRNAs (miRNAs) were upregulated and 16 were downregulated as detected with the miRNA array analysis. The upregulation of miR-149-3p and downregulation of miR-424-5p by quinidine treatment were further verified by using quantitative real-time PCR. In addition, using miRNA target prediction program, putative target genes related to cell proliferation and apoptosis for two differentially expressed miRNAs were predicted. Taken together, these data suggested that the anti-proliferative and pro-apoptosis effect of voltage-gated K+ channel blocker quinidine in human glioma cells was mediated at least partly through regulating expression of miRNAs, and provided further support for the mechanisms of voltage-gated K+ channels in mediating cell proliferation and apoptosis.