• Home
• |
• The VEGF ligand and angiogenesis
• |
• Angiogenesis as a cancer hallmark
• |
• The angiogenic process

The angiogenic process

A critical process for new cell and tissue growth

Angiogenesis, a key step in tumor growth and spread, is a biological process with multiple components. First, existing vasculature becomes permeable and dilated. Next, the extracellular matrix is degraded, followed by proliferation and migration of endothelial cells. Finally, support cells such as pericytes are recruited.²

Reprinted with permission of Sturk C, Dumont D. In: Tannock IF, Hill RP, Bristow RG, et al, eds. Basic Science of Oncology. 4th ed. New York, NY: McGraw-Hill; 2005:231-248.

An adequate supply of oxygen and nutrients is critical for homeostasis of virtually all human cells and tissues. This delivery of oxygen and nutrients—and the corresponding elimination of metabolic waste and carbon dioxide—are dependent on the vascular system. Accordingly, the formation of new tissue is systematically coordinated with the formation of a new vasculature. In this process, endothelial cells (the primary building blocks of vasculature) must undergo 4 major steps.²

The 4 major steps of endothelial cells in angiogenesis

1. Breaking through of the basal lamina that envelopes existing blood vessels

2. Migration toward a source signal

3. Proliferation

4. Formation of tubes

Like most processes in homeostatic cellular systems, angiogenesis is a complex, highly regulated system. A large number of pro-angiogenic growth factors have been identified, many of which are capable of inducing all 4 of the above steps. One of the primary factors among these is a protein known as VEGF.²

---

View references
for this site section