钾通道阻断剂抑制乳腺癌细胞增殖作用的实验研究

The Inhibition of Potassium Channel Blocker on the Proliferation of Breast Cancer Cells

目的探讨选择性钾离子通道阻断剂4-氨基吡啶(4-AP)对多西紫杉醇(DOC)抗人乳腺癌细胞MDA-MB-435S增殖、凋亡、周期的影响。方法通过MTT比色法分析DOC、4-AP以及两药联合应用对人乳腺癌细胞MDA-MB-435S增殖的影响;流式细胞术AnnexinV-FITC/PI双染法和PI单染法检测2种药物对MDA-MB-435S凋亡和周期的影响。结果0.04～50μmol/LDOC可剂量依赖性抑制人乳腺癌细胞株MDA-MB-435S的增殖;4-AP(5mmol/L)本身具有抑制MDA-MB-435S细胞的增殖作用,并可使DOC(25μmol/L)对人乳腺癌细胞株MDA-MB-435S达最大抑制率的时间明显提前,DOC和4-AP对MDA-MB-435S细胞的增殖抑制有相加或协同作用,并呈剂量和时间依赖性。DOC(2μmol/L)单用24h时促进MDA-MB-435S细胞凋亡的作用并不明显,当与4-AP(5mmol/L)联合应用后能明显增加细胞早期凋亡的发生率;单用DOC可使MDA-MB-435S细胞阻断在G2/M期,单用4-AP可使MDA-MB-435S细胞阻断在G0/G1期,两药联合应用可使细胞阻断在G2/M期。结论DOC和4-AP分别在G2/M期和G0/G1期抑制MDA-MB-435S细胞增殖,4-AP通过促进DOC诱导MDA-MB-435S细胞凋亡从而抑制其增殖作用。

Objective To study the effects of selective K^＋ channel blocker 4-AP on the action of Docetaxel on proliferation,apoptosis and cell cycle of Human Breast Cancer MDA-MB-435S cells. Methods The effects of Docetaxel, 4-AP and the combination of both drugs on proliferation of MDA-MB-435S cells were investigated by MTT assays. The number of apoptosis cells was measured by flow cytometty after the ceils were stained by Annexin-V and PI, and the changes of cell cycle were measured by flow eytometty after the cells were stained by PI. Results 4-AP （5 mmol/l） shortened the time for Docetaxel （25 μmol/1L） to reach the maximum rate of inhibiting human breast cancer cell MDA-MB-435S. Docetaxel and 4-AP had additive or synergetic effects on inhibiting proliferation of MDA-MB-435S, with time/dose dependence. The effect of Docetaxel （2 μmol/L） alone to promote MDA-MB-435S cell apoptosis was not obvious when given for 24 hours, but its combination with 4-AP （5 mmol/L） significantly increased the pristine rate of ceil apoptosis and death. MDA-MB-435S cells were blocked at G2/M period by Docetaxil alone, at G0/G1 period by 4-AP alone and at G2/M period by both Docetaxel and 4-AP. Conclusion Docetaxel and 4-AP can inhibit human breast cancer cell MDA-MB-435S proliferation by blocking cells at G2/M period and G0/G1 period, respectively. 4-AP can inhibit MDA-MB-435S proliferation by promoting the ceil apoptosis induced by Docetaxel.