Tumor Growth Factors

Two related molecules have been discovered, namely tumor growth factor-α (TGF-α), which was first found in certain virus-transformed mouse cells and present at highest levels in mid-trimester mouse and rat embryonic tissue, and VGF, which is contained in vaccinia virus, the virus used in smallpox vaccination.

Abstract

One of the first growth factors discovered was epidermal growth factor (EGF). It was found in the salivary glands of mice, as well as in the saliva. The "licking of wounds" that mice normally do was believed to speed the normal growth and repair processes. The major component was found to be EGF—a 53 amino acid single-chain polypeptide (1). The original bioassays involved a shortening of the time for mouse eyelids to open and for their toothbuds to erupt. EGF produced this effect by speeding up the growth and movement of the overlying epithelial cells. More recently, two related molecules have been discovered, namely tumor growth factor-α (TGF-α), which was first found in certain virus-transformed mouse cells and present at highest levels in mid-trimester mouse and rat embryonic tissue, and VGF, which is contained in vaccinia virus, the virus used in smallpox vaccination. Each of these is a close structural relative of EGF and interacts with the same EGF membrane receptor.