Transcription factors having impact on vascular endothelial growth factor (VEGF) gene expression in angiogenesis.

This article discusses the role of transcription factors in vascular endothelial growth factor (VEGF) gene expression. Angiogenesis is a complex and multilevel process of new capillary formation on the basis of already existing blood vessels. Physiologically, it is a very strictly regulated process, which results in a balance between stimulatory (angiogenic) and inhibitory (angiostatic) factors to control the correct development of blood vessels. There are many very well characterized angiogenic and angiostatic factors that can modulate VEGF expression. Some of them (e.g. HIF-1, AP-1, and Sp-1) are transcription factors, proteins that bind to the VEGF promoter to initiate and activate the transcription of a gene directly. Others, like nitric oxide or cytokines, are agents that stimulate the transcription factors through different cellular signaling pathways. There are also oncogenes (V-SRC, bcl-2) and tumor suppressor genes (VHL), the mutations of which lead indirectly to increased transcription of the VEGF gene.