Identification of alpha transforming growth factor as a possible local trophic agent for the mammary gland

✍ Scribed by J. A. Smith; R. Barraclough; D. G. Fernig; P. S. Rudland

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 1009 KB
• Volume: 141
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041410218

✦ Synopsis

Biologically active alpha-transforming growth factor (a-TGF) has been identified in medium conditioned by rat mammary myoepithelial and, to a lesser extent, by epithelial cell lines in culture and in the rat mammary gland. The a-TGF has been identified by its wide spectrum of activity in promoting growth of mammaryderived cells in vitro, by its chromatographic behaviour on reversed-phase highperformance liquid chromatography (HPLC), by its competition with epidermal growth factor (EGF) for the EGF receptor, and by the presence of messenger RNA for a-TGF in the secreting cells. In vivo the amount of a-TGF isolated is sixfold greater from the mammary glands of lactating than from those of virgin female rats. It is proposed that a-TGF is produced by the myocpithelial cells of the mammary gland, as a local trophic agent that stimulates growth of the various cell types of the gland.