scholarly journals Aberrant Synthesis and Secretion of a Human Epidermal Growth Factor-Like Immunoreactive Factor by Human Breast Cancer Cells

1988 ◽  
Vol 4 (1) ◽  
pp. 49-64 ◽  
Author(s):  
Kazutoshi MORI ◽  
Tomoaki YOSHIMURA ◽  
Shigeru IBARAGI ◽  
Masayuki KUROBE ◽  
Shoei FURUKAWA ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Human Epidermal Growth Factor ◽  
Epidermal Growth

scholarly journals Activation of the Na+/H+ antiport is not required for epidermal growth factor-dependent gene expression, growth inhibition or proliferation in human breast cancer cells

1989 ◽  
Vol 257 (1) ◽  
pp. 151-157 ◽  
Author(s):  
J G Church ◽  
G B Mills ◽  
R N Buick
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Cell Types ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Epidermal Growth

Mitogen interaction with specific receptors in many cell types leads to activation of the Na+/H+ antiport and a resultant cytoplasmic alkalinization. Since amiloride inhibits both Na+/H+ exchange and cell proliferation, it has been hypothesized that activation of the antiport is an obligatory requirement for mitogenesis. However, concentrations of amiloride which inhibit the antiport also inhibit other cellular processes, including protein synthesis and phosphorylation. We have used an epidermal growth factor (EGF) receptor gene-amplified human breast cancer cell line, the growth of which is inhibited by high levels of EGF in culture (MDA-468) and a variant, the growth of which is stimulated by EGF (MDA-468-S4), along with two potent amiloride analogues to examine whether activation of the Na+/H+ antiport and cytoplasmic alkalinization is necessary for both EGF-dependent effects to occur. At concentrations of the amiloride analogues which block Na+/H+ exchange in both cell types by 76-98%, the EGF-dependent alterations in [3H]thymidine incorporation or induction in c-myc or c-fos gene transcription were unaltered. These results were confirmed by a lack of effect of the amiloride analogues on both the growth-stimulatory and growth-inhibitory effects on EGF in an anchorage-independent growth assay. Similarly, in pH-altered media that prevented normal cytoplasmic alkalinization, the response of both MDA-468 and MDA-468-S4 to EGF activation was unaltered. In addition, activation of the Na+/H+ antiport alone was not sufficient to induce c-myc and c-fos transcription in either cell type. Taken together, these data suggest that neither the Na+/H+ antiport nor cytoplasmic alkalinization are necessary or sufficient for either EGF-dependent growth stimulation or growth inhibition in MDA-468 human breast cancer cells.

scholarly journals Toxicity and effects of epidermal growth factor on glucose metabolism of MDA-468 human breast cancer cells.

1990 ◽  
Vol 265 (23) ◽  
pp. 13641-13649
Author(s):  
O. Kaplan ◽  
J.W. Jaroszewski ◽  
P.J. Faustino ◽  
G. Zugmaier ◽  
B.W. Ennis ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Glucose Metabolism ◽  
Epidermal Growth Factor ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Epidermal Growth

scholarly journals Analogs of GnRH-I and GnRH-II inhibit epidermal growth factor-induced signal transduction and resensitize resistant human breast cancer cells to 4OH-tamoxifen

2005 ◽  
Vol 153 (4) ◽  
pp. 613-625 ◽  
Author(s):  
Andreas R Günthert ◽  
Carsten Gründker ◽  
Agnes Olota ◽  
Julia Läsche ◽  
Nicola Eicke ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Antiproliferative Effects ◽  
Epidermal Growth ◽  
Mcf 7

About 50–64% of human breast cancers express receptors for GnRH-I. Direct antiproliferative effects of analogs of GnRH-I on human breast cancer cell lines have been shown. They are at least in part mediated by antagonizing growth promoting effects of estradiol, epidermal growth factor (EGF) or insulin-like growth factor. Recently, expression of a putative receptor for GnRH-II in human tissues was demonstrated. Antiproliferative effects of GnRH-II in human endometrial and ovarian cancer cells were shown not to be mediated through the GnRH-I receptor. Now we demonstrate direct anti-proliferative effects of the GnRH-I analog Triptorelin and the GnRH-II analog [d-Lys6]GnRH-II in MCF-7 and T47D human breast cancer cells expressing GnRH-I receptors and putative GnRH-II receptors. Pretreatment with Triptorelin or [d-Lys6]GnRH-II blocked EGF-induced autophosphoryla-tion of EGF receptor and activation of mitogen-activated protein kinase (extracellular-signal-regulated kinase 1/2 (ERK1/2)) in these cells. In sublines of MCF-7 and T47D cells, which were developed to be resistant to 4OH-tamoxifen, HER-2/p185 was overexpressed. Pretreatment of these cell lines with Triptorelin or [d-Lys6]GnRH-II completely abolished resistance to 4OH-tamoxifen, assessed by 4OH-tamoxifen-induced apoptosis. Analogs of GnRH-I and GnRH-II counteract EGF-dependent signal transduction in human breast cancer cells with expression of receptors for GnRH-I and GnRH-II. Through this mechanism, they probably reverse acquired resistance to 4OH-tamoxifen mediated through overexpression or activation of receptors of the c-erbB family.

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