Vector Construction And Silencing Effect Of VEGF Gene Targeted Small Interfering RNA

Background and aims :Osteosarcoma is a kind of osteogenic malignant tumor which is a common clinical disease, accunt for 20% of all bone tumor. The degree of its malignancy is very high, and often occur in teenager. 80% of patients have transferred when visiting. 20%-30% of patients had taken whatever kind of treatments, their prognosis are all very unlucky. In the recently 30 years, the global therapeutic effect of osteosarcoma have no significant improvement compared with that of the 80th of 20th century. How to improve advancely the therapeutic effect and survival rate of the patients with malignancy bone tumor is an important clinical topic which need be solved urgently.A lot of researches indicated that several kinds of tumor cell and tumor cell in vitro culture both produce VEGF, and the expression of VEGF in several kinds of tumor tissues are also higher than that of their normal tissues. The expression level of VEGF in tumor tissues are direct correlated with vascularization and degree of malignancy of tumor. VEGF plays an important role in stimulating blood vessel growing. Increasing permeability of capillary vessel, specificly binding with the receptor of vascular endothelial cell, stimulating disintegration and proliferation of vascular endothelial cell then resulting in the formation of new vessels.There are two...