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[Expression and properties of potassium channels in human mammary epithelial cell line MCF10A and its possible role in proliferation.] [Ariticle in Chinese]

Liu Jia, FENG Shuang, ZHANG Lei, WU Zheng, CHEN Qian, CHENG Wei, WANG Shi-Qiang, ZOU Wei

College of Life Science, Liaoning Normal University, Dalian 116029, China； Liaoning Key Laboratories of Biotechnology andMolecular Drug Research and Development, Dalian 116029, China； School of Physics and Optoelectronic Engineering, DalianUniversity of Technology, Dalian 116026, China； College of Life Sciences, Peking University, Beijing 100871, China

Abstract

Voltage-dependent potassium channels (Kv) are involved in proliferation and transformation in mammary epithelial cells. Inprevious studies, several groups have detected various potassium channels in breast cancer cells, and they assumed that potassiumchannels are related to the development of breast carcinoma, although the precise mechanisms are still unknown. We have previouslyreported that 4-aminopyridine (4-AP), one kind of potassium channel (K+ channel) blocker, could affect the proliferation of MCF10Acells. The aim of the present study is to explore the expression and properties of K+ channels in human mammary epithelial cells(MCF10A) and whether Kv channels are required for the proliferation of MCF10A cell. Electrophysiological, MTT analysis, PCR andWestern blot methods were used to identify a K+ conductance which is involved in tumorigenesis and not yet be described in MCF10Acells. A voltage-dependent, outward rectification and 4-AP-sensitive K+ current was observed in these cells. The perfusion of 5 mmol/L4-AP significantly decreased the amplitude of Kv current from (912.5±0.6) pA to (275±0.8) pA (n=5, P<0.01), when cells wererecorded using 800 ms voltage steps from a holding potential of -60 mV to voltage ranging from -60 mV to +60 mV. PCR analysis demonstrated that Kv1.1, Kv1.2, Kv1.3, and Kv1.5 were all expressed in MCF10A and MCF7 cells. Furthermore, the expression ofKv1.5 was much higher in MCF10A than that in MCF7. Inhibitory effect of 4-AP on cell proliferation was dosage-dependent.Incubation with 5 mmol/L 4-AP reduced MCF10A cell proliferation to 25.29% in 48 h. Western blot analysis showed the activation ofERK1/2 which related to cell proliferation was enhanced, while p38 activation was decreased by 4-AP treatment for 10 min. These dataprovided the first evidence of the Kv channels expression in MCF10A cell and 4-AP could inhibit the proliferation of MCF10A throughblocking the potassium channels, and the mechanism may be related to regulating the activity of different members of cell proliferationsignaling pathway of MEK/ERK.

Key words: voltage-gated K+ channel; human mammary epithelial cell line

Received: 2010-01-04　　Accepted: 2010-05-20

Corresponding author: 邹伟　　E-mail: weizou60@126.com

Citing This Article：

Liu Jia, FENG Shuang, ZHANG Lei, WU Zheng, CHEN Qian, CHENG Wei, WANG Shi-Qiang, ZOU Wei. [Expression and properties of potassium channels in human mammary epithelial cell line MCF10A and its possible role in proliferation.] [Ariticle in Chinese] . Acta Physiol Sin 2010; 62 (3): 203-209 (in Chinese with English abstract).