Interplay of Ca2+ and K+ signals in cell physiology and cancer.

The cytoplasmic Ca²⁺ concentration and the activity of K⁺ channels on the plasma membrane regulate cellular processes ranging from mitosis to oriented migration. The interplay between Ca²⁺ and K⁺ signals is intricate, and different cell types rely on peculiar cellular mechanisms. Derangement of these mechanisms accompanies the neoplastic progression. The calcium signals modulated by voltage-gated (K_V) and calcium-dependent (K_Ca) K⁺ channel activity regulate progression of the cell division cycle, the release of growth factors, apoptosis, cell motility and migration. Moreover, K_V channels regulate the cell response to the local microenvironment by assembling with cell adhesion and growth factor receptors. This chapter summarizes the pathophysiological roles of Ca²⁺ and K⁺ fluxes in normal and cancer cells, by concentrating on several biological systems in which these functions have been studied in depth, such as early embryos, mammalian cell lines, T lymphocytes, gliomas and colorectal cancer cells. A full understanding of the underlying mechanisms will offer a comprehensive view of the ion channel implication in cancer biology and suggest potential pharmacological targets for novel therapeutic approaches in oncology.