Читать книгу Autologous Blood Concentrates - Arun K Garg - Страница 15

As its name suggests, the protein-based VEGF helps to develop blood vessels by interacting with endothelial cells, stimulating the synthesis of basal lamina, and recruiting pericytes^69,100 (Fig 1-10). Like several other growth factors, VEGF is known for and studied scientifically mainly due to its activity in pathologic states rather than healthy ones. The role it plays in the formation of new blood vessels of cancerous tumors has provided much of what we know of its abilities to stimulate growth in other cells. Tumors, just like healthy cells, can synthesize growth factor proteins—including VEGF—that promote the formation of new blood vessels from existing ones (angiogenesis). Instead of angiogenesis taking place for normal body growth or tissue repair, in this pathologic process it enables the spread of cancerous cells. In this case, VEGF activity leads to the development of capillaries within the tumor because of its stimulation of endothelial cells, which are the raw materials needed for angiogenesis. Endothelial cell division leads to the growth and migration of the tumor cells, developing a cascade of shared growth factors between their cells. Possible cancer therapies, therefore, include ways to introduce proteins into the tumor that slow or stop angiogenesis.

FIG 1-11 Effects of platelet-leukocyte aggregates on differentiation, activation, and cytokine release.