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Estrogen enhances epidermal growth factor‐induced DNA synthesis in mammary epithelial cells
Author(s) -
Vanderboom Russell J.,
Sheffield Lewis G.
Publication year - 1993
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041560220
Subject(s) - estrogen , epidermal growth factor , dna synthesis , estrogen receptor , priming (agriculture) , medicine , endocrinology , biology , receptor , cell growth , cell , microbiology and biotechnology , in vitro , biochemistry , botany , germination , cancer , breast cancer
Estradiol (E 2 ) 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 2 and EGF was evident in two aspects: After serum‐free synchronization for 24 h, more cells entered the S‐phase of the cell cycle after E 2 priming and when treated with 0.17 nM EGF (13%) than did control cells (1.3%) or cells treated with EGF (4%) or E 2 (3.5%) alone; further, the dose of EGF required to elicit maximal response was reduced an order of magnitude in estrogen‐primed cells (0.17 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) compared to estrogen deprived cells (1,960 receptors/cell). © 1993 Wiley‐Liss, Inc.