Angiotensin II Receptor Blocker: Possibility of Antitumor Agent for Prostate Cancer

It is known that the renin-angiotensin system (RAS) plays a fundamental role not only as a vasoconstrictor incontrolling blood pressure and electrolyte/fluid homeostasis, but also as a mitogenic factor through the Ang-II type-1(AT1) receptor in smooth muscle cells and cardiac myocytes. Angiotensin II (Ang-II) is indeed thought to be a growthfactor, and Ang-II receptor blockers (ARBs), a class of antihypertensive agent, suppress signal transduction pathwaysmediated by several growth factors or cytokines, through the AT1 receptor. There is increasing evidence that the RAS isimplicated in the development of various cancers. We previously demonstrated that ARBs have the potential to inhibit thegrowth of prostate cancer cells and tumors through the AT1 receptor. This review highlights the possibility of ARBs asnovel agents for prostate cancer as well as other cancers, and reviews the literature on this area.