Inhibition of voltage‑gated potassium channels affect expressions of miR-126 and miR-126* in breast cancer cell lines.

We aimed to determine the possible correlation between voltage‑gated potassium channels and micro RNAs in breast cancer and metastatic breast cancer cells. Kv1.3 and Kv10.1 channels were inhibited by specific siRNAs using a lipofectamine-based transfection in MCF-7 and MDA-MB-231 cells. After transfection, total RNA was isolated, and then miR-126 and miR-126* expressions were observed using RT-PCR. There was a negative correlation between Kv channels and miRNAs according to the characteristics of the breast cancer cells. The inhibition was observed not only in Kv1.3 but also in Kv10.1 in MCF-7 cells, and miR-126 and miR-126* expressions were downregulated compared to the control group (p < 0.001). The inhibition of these channels in MDA-MB-231 cells caused an upregulation of miR-126 and miR-126* expressions (p < 0.001). The miR-126 and miR-126* expressions differed according to benign and malign breast cancer cell lines. Furthermore, we found that miR-126/126* may interact with Kv1.3 and Kv10.1 voltage-gated potassium channels. Our study suggests and indicates the relationship between Kv channels and miRNAs in breast cancer cells (Tab. 1, Fig. 2, Ref. 51).