490: Long chain alkylphenol mixture promotes mammary epithelial cell metaplastic phenotype through an estrogen receptor alpha 36 mediated mechanism

2014 ◽  
Vol 50 ◽  
pp. S118
Author(s):  
C. Chamard ◽  
E. Bresso ◽  
T. Boukhobza ◽  
M.D. Devignes ◽  
M. Smaïl-Tabbone ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Epithelial Cell ◽  
Mammary Epithelial Cell ◽  
Estrogen Receptor Alpha ◽  
Mammary Epithelial ◽  
Receptor Alpha ◽  
Long Chain

scholarly journals Mammary Fat Can Adjust Prolactin Effect on Mammary Epithelial Cells via Leptin and Estrogen

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Yonatan Feuermann ◽  
Sameer J. Mabjeesh ◽  
Avi Shamay
Keyword(s):  
Estrogen Receptor ◽  
Epithelial Cells ◽  
Estrogen Receptor Alpha ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Fat Pad ◽  
Paracrine Factors ◽  
Receptor Alpha ◽  
Mammary Fat Pad ◽  
Aromatase Mrna

Leptin, like estrogen, is one of the endo/paracrine factors, which are synthesized in and secreted from mature adipocytes. The roles of the mammary fat pad and mammary adipocytes in the initiation of lactation are not clear. In this study, we showed that combination of prolactin, leptin and estrogen elevated the expression of the milk protein beta-lactoglobulin. We also showed that after prolactin stimulate the secretion of leptin from the mammary fat, leptin upregulated the expression of estrogen receptor alpha in the mammary epithelial cells. Also, prolactin affected aromatase mRNA expression in the bovine mammary fat and we demonstrated that leptin and prolactin can affect cholesterol secretion from explants in culture to the medium. Therefore, we suggest that prolactin initiates estrogen expression (as represented by aromatase mRNA) in the mammary fat pad, whereas leptin stimulates estrogen receptor alpha expression in the mammary epithelial cells. We hypothesize that leptin and estrogen, secreted from the mammary fat regulate lactation after stimulation of prolactin.

Overexpression of Mos, Ras, Src, and Fos inhibits mouse mammary epithelial cell differentiation

1992 ◽  
Vol 12 (9) ◽  
pp. 3890-3902
Author(s):  
B Jehn ◽  
E Costello ◽  
A Marti ◽  
N Keon ◽  
R Deane ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mammary Epithelial Cell ◽  
Mammary Epithelial Cells ◽  
Binding Activity ◽  
Mammary Epithelial ◽  
Dna Binding Activity ◽  
Beta Casein ◽  
Lactogenic Hormones

Mammary epithelial cells terminally differentiate in response to lactogenic hormones. We present evidence that oncoprotein overexpression is incompatible with this hormone-inducible differentiation and results in striking cellular morphological changes. In mammary epithelial cells in culture, lactogenic hormones (glucocorticoid and prolactin) activated a transfected beta-casein promoter and endogenous beta-casein gene expression. This response to lactogenic hormone treatment was paralleled by a decrease in cellular AP-1 DNA-binding activity. Expression of the mos, ras, or src (but not myc) oncogene blocked the activation of the beta-casein promoter induced by the lactogenic hormones and was associated with the maintenance of high levels of AP-1. Mos expression also increased c-fos and c-jun mRNA levels. Overexpression of Fos and Jun from transiently transfected constructs resulted in a functional inhibition of the glucocorticoid receptor in these mouse mammary epithelial cells. This finding clearly suggests that glucocorticoid receptor inhibition arising from oncogene expression will contribute to the block in hormonally induced mammary epithelial cell differentiation. Expression of Src resulted in the loss of the normal organization and morphological phenotype of mammary epithelial cells in the epithelial/fibroblastic line IM-2. Activation of a conditional c-fos/estrogen receptor gene encoding an estrogen-dependent Fos/estrogen receptor fusion protein also morphologically transformed mammary epithelial cells and inhibited initiation of mammary epithelial differentiation-associated expression of the beta-casein and WDNM 1 genes. In response to estrogen treatment, the cells displayed a high level of AP-1 DNA-binding activity. Our results demonstrate that high cellular AP-1 levels contribute to blocking the ability of mammary epithelial cells in culture to respond to lactogenic hormones. This and other studies indicate that the oncogene products Mos, Ras, and Src exert their effects, at least in part, by stimulating cellular Fos and probably cellular Jun activity.

Sign in / Sign up

Export Citation Format

Share Document