Role of Calcium-Activated Potassium Channels in Proliferation, Migration and Invasion of Human Myeloid Leukemia Cells

Calcium-activated potassium channels (KCa) are the important participants in calcium signaling pathways due to their ability to be activated by increase of the intracellular free calcium concentration. KCa channels are involved in the regulation of various processes in the cells under normal, as well as pathophysiological conditions, including oncotransformation. Previously, with the use of patch-clamp method, we registered the KCa activity in the plasma membrane of human myeloid leukemia K562 cell line. Here, we performed the molecular and functional identification of KCa channels and have uncovered their role in proliferation, migration and invasion of K562 cells. Using a combined approach, we identified the functional activity of SK2, SK3 and IK channels in the plasma membrane of the cells. Selective SK and IK channel inhibitors, apamin and TRAM-34, reduced the proliferative, migratory and invasive capabilities of human myeloid leukemia cells. At the same time, the viability of K562 cells was not affected by KCa channel inhibitors. Our data imply that SK/IK channel inhibitors could be used to slow down the proliferation and spreading of leukemia cells that express functionally active KCa channels in the plasma membrane.