Effects Of Kv1.5Gene Knock-down On Proliferation Mediated By Akt Signaling Pathway In Human Mammary Epithelium Cells MCF10A

K+channel is the most abundant and widely distributed ion channel. It plays a major role in the signal transduction pathway of excitable cells and unexcitable cells and involved in cell proliferation and differentiation etc. Kv1.5channel (also named KCNA5) is encoded by KCNA5gene, which belongs to the family of voltage-gated ion channel. Since1990, it has been cloned from rat brain for the first time, Kv1.5was found in many tissues including brain, heart, liver, kidney and some of their malignant counterparts. Many reports indicated that Kv1.5is correlated closely to the generation and development of breast cancer. Thus, research on Kv1.5mechanism in cell proliferation and further investigation of Kvl.5as therapeutic target is important to clinical prevention and treatment of breast cancer.Studies have shown that Kv1.5channels was associated with Caveolin-1(Cav-1) in multiple cell types. Our previous work showed that the expression of Kv1.5and Cav-1in MCF-7cells were significantly lower than that of MCF10A cells. The results suggested that Kv1.5channels may be involved in breast cell proliferation and Cav-1may be also involved. In this study, we established cell mode--MCF10AKv1.5(-) expressed a low level of Kvl.5and detected the effects of Kv1.5on cell proliferation, cell signaling and the interactions between Kv1.5and Cav-1by cell counting, Western blot and immunofluorescence.Results:(1) We established Kv1.5knock down MCF10AKv1.5(-)and control (MCF10Ashuffle) cell lines respectively. To assess cell proliferation, we compared the growth curve and the double time between MCF10AKv1.5(-) and MCF10Ashuffle cells.Kvl.5gene knock-down inhibited the proliferation of MCF10A cells, and increased the expression of PCNA.(2) Western blot showed that Kvl.5gene knock-down inhibited the activation of Akt signaling pathway and promoted the cross-talk between MAPK and Akt signaling pathway in MCF10A cells.(3) Dual-immunofluorescence indicated that both Kv1.5and Cav-1were located on the cell membrane with strong co-localization in MCF10A cells. However, both Cav-1and Kvl.5on the cell membrane were downregulated in MCF10ACE cells.Conclusion:Kv1.5could interact with Cav-1in human mammary epithelial cells MCF10A and its gene knock-down may inhibit the cell proliferation mediated by Akt signaling pathway.