The Notch Pathway and Sox17 Expression (p 215)
Notch suppresses Sox17 expression to inhibit vascular branching, report Lee et al.
Angiogenesis is essential for human development, growth and wound healing, but it can also be an undesirable process in some situations such as cancer, where it promotes tumor growth. Thus, understanding the mechanisms that increase or inhibit angiogenesis has high clinical significance. During angiogenesis, certain endothelial cells of the growing vessels become tip cells, which stretch out from the main channel and ultimately give rise to new branches. While it has been known for some time that Notch signaling suppresses tip cell formation, the downstream targets of Notch have not been identified. Now, Lee and colleagues report that Notch inhibits the expression of the transcription factor Sox17. They found that overexpression of Notch in endothelial cells led to specific downregulation of Sox17 protein, …