Research progress of tumor angiogenesis inhibitors

Abstract

Angiogenesis is one of the most important pathological characteristics in the development of tumor growth. Hence, antiangiogenesis is a hot topic in the field of cancer research. The current strategy for antiangiogenesis therapy of tumors is restoration of the angiogenic balance via either blockage of proangiogenic factors or application of angiogenic inhibitors. Endogenous angiogenic inhibitors show more promising prospects compared with proangiogenic factor antagonists. However, the underlying mechanisms of angiogenic inhibitors remain to be thoroughly elucidated. There are two types of endogenous angiogenic inhibitors. The first are hydrolyzed fragments of precursor proteins, such as plasminogen kringle 5 (K5), angiostatin/kringle 1–4, and endostatin, and the other are secreted proteins, such as pigment epithelium-derived factor (PEDF), kallikrein-binding protein (KBP/kallistatin), and antithrombin. Here we summarized research progress on the biological functions underlying mechanisms of tumor angiogenesis and application prospects of K5, PEDF, and KBP, so as to provide insights into the antiangiogenic therapies of tumor in the future.