TRPV Family Ion Channels in the Mammary Epithelium: Role in Normal Tissue Homeostasis and along Breast Cancer Progression

Calcium homeostasis directs various intracellular cascades and therefore strict spatio-temporal control of calcium influx is also crucial for diverse physiological processes. In the mammary gland, calcium is important for the specialized tasks of this organ during lactation, but it also guides other structural and functional features of the mammary epithelium and in this way the maintenance of the whole tissue. Transient receptor potential, TRP, family ion channels are cationic channels, permeable to both monovalent and divalent cations and play a role in the influx of calcium mainly through the plasma membrane. These channels also represent vital calcium entry routes in the mammary epithelium and may thus act as central players in the preservation of calcium balance within this tissue. Moreover, TRP family channel proteins are abnormally expressed in breast cancers and may promote cancer progression through deregulation of intracellular signaling, consequently triggering several hallmarks of cancer. This chapter concentrates on the role of transient receptor potential vanilloid, TRPV, a subfamily of proteins in the calcium-dependent functions of normal mammary epithelium and the evident role of these channel-forming proteins along breast cancer progression