Hormone Epidermal Growth Factor Interactions in Development

Abstract

Epidermal growth factor (EGF) is the most important member of a family of growth factors which exert their effects via a single 170,000 M_r plasma membrane receptor. Other members include transforming growth factor-α (TGF-α), amphiregulin and several viral growth factors. The receptor is widely distributed in fetal and postnatal tissues. The predominant family member in the fetus appears to be TGF-α. EGF production in tissues matures in the perinatal period. Activation of the receptor in the fetal and neonatal periods in rodents evokes important growth and development actions. Tissue EGF and EGF receptor concentrations are modulated by thyroid hormones, estrogen, testosterone and growth hormone, suggesting that selected growth and developmental actions of thyroid and steroid hormones may be mediated by EGF

Regulation of surface‐differentiation molecules by epidermal growth factor, transforming growth factor alpha, and hydrocortisone in human mammary epithelial cells transformed by an activated c‐Ha‐ras proto‐oncogene

“…This finding may be relevant to the growth of cells in vivo, since HC is an endogenous hormone capable also of reducing HLA-class-1-antigen expression, while TGF-a is autonomously secreted by transformed cells. Other steroid hormones, such as estradiol and testosterone, have been already reported to stimulate TGF-a production (Fisher, 1990;Manni et ul., 1990), but their influence on the expression of EGF-R had not been investigated previously. In our experiments, exogenous EGF reduced in a dose-dependent manner the expression of immunoreactive EGF-R in both lines, and the reduction of EGF-binding sites per cell was significantly greater in c-Ha-rus-transfected cells than in parental cells.…”

Effect of various growth-promoting factors on preimplantation bovine embryo development in vitro

“…EGF and members of the EGF family (TGF-a and amphiregulin) can bind t o EGF receptors to elicit an increase in tyrosine phosphorylation (16,17). This phosphory lation is a critical step in the signal transduction pathway.…”

Androgen regulation of epidermal growth factor receptor binding activity during fetal rabbit lung development.

“…Other hormones have been shown to affect levels of EGF receptor mRNA or EGF binding. Thyroid hormone increases EGF receptor mRNA levels in adult mouse liver (47,48) and the absence of thyroid hormones (congenital hypothyroidism) delays EGF receptor binding in neonatal mouse liver (49). Similarly, estrogens increase EGF receptor mRNA levels in mouse uterine tissue (50).…”