Figure 2

Antiangiogenic Gene Therapy: Recent Developments. The figure depicts different modes of gene therapy directed to tumor endothelial cell (EC) and its microenvironment. The expression of EC specific cell surface molecules like, vascular endothelial growth factor receptor (VEGFR), E selectin or angiogenic growth factors (VEGF, FGF, PDGF) produced by tumor cells can be inhibited by specific antibodies or antisense RNA or using gene specific SiRNA. The targeted gene therapy can be achieved by using either viral vectors or nanoparticles carrying ligand (RGD) to endothelial cell surface specific receptors (αvβ5, αvβ3) to target antiangiogenic genes to tumor vasculature. The inhibitors can also selectively express in EC using endothelial cell specific promoters like endothelin 1 (EDT1). Ad: adenovirus; AAV: adeno-associated virus; Retro: retrovirus; VEGF: vascular endothelial growth factor; FGF: fibroblast growth factor; PDGF: platelet derived growth factor; TNF: tumor necrosis factor; RGD: Arginine-glycine-aspartic acid; SiRNA: small interfering RNA