钾通道阻断剂对人乳腺上皮细胞MCF10A增殖的影响

Effect of potassium channel antagonist on proliferation in the human mammary epithelial cells MCF10A

探讨电压门控钾离子通道在乳腺上皮细胞增殖过程中的作用.通过MTT法检测了钾通道阻断剂TEA、电压门控钾通道阻断剂4-AP对人乳腺上皮细胞MCF10A增殖的影响并与乳腺癌细胞MCF7作了比较,免疫印迹方法观察了电压门控钾通道Kv1.2、Kv1.5的表达.研究发现,两种钾离子通道阻断剂对人乳腺细胞和乳腺癌细胞增殖的影响均呈剂量依赖性关系.经5mmol/LTEA处理72h后,MCF10A细胞的生长抑制率为21.67%,而MCF7细胞的生长抑制率为41.36%;5mmol/L4-AP处理72h后,MCF10A的生长抑制率为29.24%,而MCF7细胞的生长抑制率为40.24%.Kv1.2在MCF10A和MCF7中表达没有变化,而Kv1.5在MCF10A细胞中的表达明显高于MCF7细胞.提示电压门控钾离子通道在乳腺细胞的增殖中起重要作用,其中Kv1.5可能和乳腺细胞的转化密切相关.

Previous work has shown that voltage-gated potassium channels are crucial for breast cancer （e. g MCFT） cell proliferation; but the function and mechanism of these channels in proliferation of normal human mammary epithelial cells has been left largely unknown in MCF10A, so, we carry on with the study. Firstly, the effect of tetraethylammonium （TEA, a potassium channel blocker） and 4- aminopyridine （4-AP, a voltage-gated potassium channel blocker） on MCF10A cell line was detected by MTT methods. Secondly, expressions of different Kv channels, including Kv1. 2, Kv1. 5, were determined by blot technique. Results show that： （1）5-10mmol/L of TEA and 4-AP treatment for 72 h could significantly inhibit proliferation of MCF10A and MCF7 breast cancer cell lines; and the latter was more sensitive to both blockers. （2）Kv1. 2, Kv1. 5 expressed in both cell lines. The Kv1. 5 protein level in MCF10A was higher than that in the MCF7 cells. These results strongly suggest that voltage-gated potassium channel-Kv1. 5 may play an important physiological role in the regulation of proliferation.