Anti-angiogenic Therapy for Tumor: Tumor Angiogenesis, Vasculogenic Mimicry and Vascular Normalization

The growth and metastasis of solid tumors require a sufficient blood supply that provides oxygen and nutrients. In recent years, targeting tumor vasculature has gained rapid development, owing to the abnormalities of tumor blood vessels compared with normal blood vessels. There are three aspects for targeting blood vessels in tumor treatment, including angiogenesis, vasculogenic mimicry (VM) and vascular normalization. Anti-angiogenic therapy is an anti-tumor strategy targeting to the new blood vessels. VM is an alternative form of blood supply not depending on endothelial vessels, but insteading to form a tubular structure similar to blood vessels by the tumor cells themselves. However, anti-angiogenic therapy may have some limits such as tumor hypoxia, reduction of chemotherapy drugs approaching to tumors, etc. As a different approach to anti-tumor therapy, vascular normalization provides a new idea for the cancer treatment. In this review, we summarized the advanced researches on therapies of anti-angiogenic, anti-VM and vascular normalization, including their molecular mechanisms and clinical significances.