Treeck, Oliver and Weber, Angela and Boester, Michaela and Porz, Simone and Frey, Nicola and Diedrich, Klaus and Ortmann, Olaf (2003) H-ras dependent estrogenic effects of epidermal growth factor in the estrogen-independent breast cancer cell line MDA-MB-231. BREAST CANCER RESEARCH AND TREATMENT, 80 (2). pp. 155-162. ISSN 0167-6806
Full text not available from this repository. (Request a copy)Abstract
A crosstalk between cellular estrogen response and receptor tyrosine kinase signaling has been shown in a variety of estrogen receptor (ER)-positive cell lines. We intended to examine the presence of estrogenic growth factor effects in an ER alpha-negative breast cancer cell line. By means of reporter gene assays, we investigated the activation of estrogen response elements (EREs) by epidermal growth factor (EGF) in the estrogen-unresponsive cell line MDA-MB-231. Our results demonstrate the H-ras-dependent activation of EREs after EGF treatment in this estrogen-unresponsive cell line, an effect which was not observed in the ERalpha/beta-positive breast cancer cell line MCF-7. In MDA-MB-231 cells, the transcriptional activity of an ERE-containing promotor was enhanced dose dependently by all tested EGF concentrations. This effect could be blocked by co-treatment with the epidermal growth factor receptor (EGFR) inhibitors AG1478 and ZD1839, as well as by co-transfection with a vector coding for a dominant negative H-ras mutant, but not by co-treatment with the pure antiestrogen ICI182,780. Furthermore, expression of constitutively active H-ras was shown to be sufficient to activate EREs in MDA-MB-231 cells. Our results suggest alternative utilization of ERE-mediated gene regulation in an estradiol-unresponsive breast cancer cell line in response to an EGF stimulus. This mechanism was shown to be dependent on EGFR and H-ras activity, but independent of the presence of functional ERalpha.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PROTEIN-KINASE; CROSS-TALK; RECEPTOR; ACTIVATION; PHOSPHORYLATION; EGF; BINDING; PATHWAY; DOMAIN; epidermal growth factor; estrogen receptor; estrogen response element; H-ras; MDA-MB-231 cell |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Frauenheilkunde und Geburtshilfe (Schwerpunkt Frauenheilkunde) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 06 Sep 2021 09:38 |
| Last Modified: | 06 Sep 2021 09:38 |
| URI: | https://pred.uni-regensburg.de/id/eprint/38843 |
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