Angiotensin-I converting enzyme inhibitors (ACE-Is) are commonly used as safe
antihypertensive agents, and it has recently been suggested that they decrease the risk of
cancer development. Recent studies have revealed that the renin-angiotensin system (RAS) is involved in the development of many types of
tumor.
Angiotensin-II (AT-II) has many biological effects, including neo-vascularization, which plays a pivotal role in
tumor development. AT-II induces a potent
angiogenic factor, namely the
vascular endothelial growth factor (
VEGF). Some studies have proven that several ACE-Is are potent inhibitors of experimental
tumor development and angiogenesis at clinically comparable doses.
VEGF expression in
tumors is also significantly suppressed by ACE-Is. When used in combination with the conventional anti-
cancer drugs, ACE-Is exert more potent anti-
tumor activities as compared with either single agent, in addition to suppression of the intra-tumoral angiogenesis. Furthermore, ACE-Is reportedly not only suppress
tumor growth but also attenuate the
carcinogenesis process in which angiogenesis is involved. Since ACE-Is are already in widespread clinical case without any serious adverse effects, they may represent a potential new strategy for
cancer therapy and
chemoprevention.