The Regulation And Mechanism Study Of SK4 Channels On The Malignant Biological Behavior Of Triple-Negative Breast Cancer Cells

Treatments for triple-negative breast cancer (TNBC) are limited and new effective target is in urgency.Intermediate-conductance calcium-activated potassium (SK4) channels are closely involved in tumor progression, but little is known about these channels in TNBC. We aimed to investigate whether SK4 channels affect TNBC. First, by immunohistochemistry (IHC) and western blotting (WB), increased SK4 protein expression in breast tumor tissues was detected relative to that in non-tumor breast tissues. Next, functional SK4 channels were detected in the TNBC cell line MDA-MB-231. By employing SK4 specific siRNAs and modulators, we found that the down-regulation of SK4 channels significantly inhibited cell proliferation and migration, and promoted apoptosis in MDA-MB-231 cells. Further investigation revealed that treatment with epidermal growth factor (EGF)/basic fibroblast growth factor (bFGF) caused MDA-MB-231 cells to undergo the epithelial-mesenchymal transition (EMT) and to show increased SK4 mRNA expression level. In addition, the down-regulation of SK4 expression inhibited the EMT markers Vimentin and Snaill. Collectively, our findings suggest that SK4 channels are expressed in TNBC and are involved in the proliferation, apoptosis, migration and EMT processes of TNBC cells.