Cancer

Ion channels have long been known to be involved in the regulation of a variety of biological functions ranging from the control of cell excitability to the regulation of cell volume and proliferation. Because of the ubiquitous presence of ion channels in virtually all cells and their critical involvement in diverse biological functions, it came as no surprise when several human and animal diseases were attributed to defects in ion channel function. Indeed, the term channelopathies was coined to describe the ever growing number of diseases associated with ion channel function. Channelopathies have been recognized in the context of conditions as diverse as epilepsy¹, cardiac arrhythmias², skeletal muscle disorders³ and diabetes⁴.

During the last few years a pivotal role for ion channels involvement in cancer has emerged. In Modulator #17, we reviewed examples of possible roles and interplay between ion channels and cancer. Recently, a large body of data has accumulated on the participation of K⁺, Na⁺, Ca²⁺, Cl^– and ligand-gated channels in cancer and apoptosis. To date, there is no broad consensus on the roles ion channels play in cancer. Ion channels are thought to “assist” cancer by affecting a number of pathways, namely, regulation of cell cycle of proliferating cells, perturbation of membrane potential, prevention of apoptosis, adaptation to harsh conditions, altering intracellular Ca²⁺ balance, and cell shrinkage. Interestingly, there are some examples of the same ion channel participating both in induction of cancer cell proliferation and in