Estrogen enhances epidermal growth factor-induced DNA synthesis in mammary epithelial cells

✍ Scribed by Russell J. Vanderboom; Lewis G. Sheffield

• Book ID: 102883853
• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 543 KB
• Volume: 156
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041560220

✦ Synopsis

Estradiol (E,) priming (1 nM for 48 h) of normal murine mammary gland epithelial cells significantly increased the response of those cells to epidermal growth factor (EGF)-induced DNA synthesis. The synergism between E, and EGF was evident in two aspects: After serurn-free synchronization for 24 h, more cells entered the S-phase of the cell cycle after E, priming and when treated with 0.17 nM EGF (13%) than did control cells (1.3%) or cells treated with EGF (4%) or E, (3.5%) alone; further, the dose of ECF required to elicit maximal response was reduced an order of magnitude in estrogen-primed cells (0.1 7 nM) compared to controls (1.7 mM). Estrogen alone, however, did not increase DNA synthesis in these cells.

Ligand binding studies indicate that these effects of estrogen on proliferating mammary epithelial cells may be explained, at least in part, by a 3.7-fold increase in the number of high affinity EGF-receptors observed in estrogen primed cells (7,300 receptors per cell) cornpared to estrogen deprived cells (1,960 receptors/ cell).