An Experimental Research Of Gene Therapy Of Human Glioma With Antiangiogenesis

Angiogenesis, the formation of new capillary blood vessels from pre-existing ones, is a complicated process, which is controlled by many angiogenesis stimulating factors and inhibitory factors. Normal angiogenesis is strictly limited to some special transient physiological processes, such as embryogenesis, wound repair, and etc. But continuous angiogenesis is the characteristic of some pathlogical changes, such as tumor angiogenesis.The tumor cell is the organizer for its angiogenesis.It can overexpress several angiogenesis stimulating factors(such as VEGF , FGF , angiopoietin and etc), secrete many enzymes(such as uPA and MMP), mobilize the needed proteins and enzymes from the cell matrix(such as integrin α_v β₃ and α_v β₅), recruit the host cells to secrete promoting angiogenesis factors(macrophage, lymphocyte and fibroblast). Both upregulation of angiogenic stimulators and downregulation of angiogenesis inhibitors result in tumor blood vessel proliferation, which is the bases of the tumor growth and metastasis.Direct experimental evidences show that solid tumor growth and metastasis require new blood vessels. An avascular tumor (vascular prophase) rarely grows to a size larger than 0.4 mm³ and grows at a slow linear growth speed. Once a tumor...