Definition
Human growth factors are compounds made by the body that function to regulate cell division and cell survival. Some growth factors are also produced in the laboratory by genetic engineering and are used in biological therapy.
Description
Human tumors express large amounts of growth factors and their receptors. A tumor will not grow beyond the size of a pinhead without new blood vessels to supply oxygen and nutrients. Growth factors are significant because they can induce angiogenesis, the formation of blood vessels around a tumor. These growth factors also encourage cell proliferation, differentiation, and migration on the surfaces of the endothelial cells—cells found inside the lining of blood vessels. Of the approximately 20 proteins that activate endothelial cell growth, two growth factors in particular, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), are expressed by many tumors and appear important in contributing to tumor growth and promoting tumor spread throughout the body. Several compounds that block VEGF or its receptor are now in clinical trials.
—Crystal Heather Kaczkowski, MSc.
