scholarly journals Phorbol Ester or Epidermal Growth Factor (EGF) Stimulates the Concurrent Accumulation of mRNA for the EGF Receptor and Its Ligand Transforming Growth Factor-α in a Breast Cancer Cell Line

1989 ◽  
Vol 264 (7) ◽  
pp. 4021-4027
Author(s):  
J D Bjorge ◽  
A J Paterson ◽  
J E Kudlow
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Phorbol Ester ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Cancer Cell Line ◽  
Transforming Growth Factor Α ◽  
Epidermal Growth ◽  
Factor Α

scholarly journals The linear C-terminal regions of epidermal growth factor (EGF) and transforming growth factor-α bind to different epitopes on the human EGF receptor

1998 ◽  
Vol 336 (1) ◽  
pp. 147-151 ◽  
Author(s):  
Anne E. G. LENFERINK ◽  
Albert D. G. De ROOS ◽  
Marianne J. H. Van VUGT ◽  
Monique L. M. Van De POLL ◽  
Everardus J. J. Van ZOELEN
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Calcium Release ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Binding Characteristics ◽  
Transforming Growth Factor Α ◽  
Identical Manner ◽  
Epidermal Growth ◽  
Factor Α

Epidermal growth factor (EGF) and transforming growth factor-α (TGFα) bind with similar affinities in a competitive fashion to the human EGF receptor, and basically induce similar mitogenic responses. In spite of the fact that EGF and TGFα are structurally alike, it is still not clear if the two growth factors bind the receptor in an identical manner. The observation that the 13A9 antibody blocks binding of TGFα, but not that of EGF, to the human EGF receptor [Winkler, O'Connor, Winget and Fendly (1989) Biochemistry 28, 6373–6378] suggests that their binding characteristics are not identical. In the present study we have made use of a set of EGF/TGFα chimaeric molecules to show that the 13A9 antibody blocks receptor binding of ligands with TGFα sequences, but not of ligands with EGF sequences, in their C-terminal linear regions. Using HaCaT human keratinocyte cells in culture, it was determined that ligands that are able to bind the EGF receptor in the presence of 13A9 are also able to induce calcium release from intracellular stores in these cells, indicating that these ligands have the ability to activate the EGF receptor in the presence of the antibody. From these data it is concluded that the flexible C-terminal linear domains of EGF and TGFα bind to separate sequences on the EGF receptor, such that the binding domain of TGFα, but not that of EGF, overlaps with the binding epitope of the 13A9 antibody.

Steroidal regulation of oestradiol-17β dehydrogenase activity of the human breast cancer cell line MCF-7

1988 ◽  
Vol 118 (1) ◽  
pp. 149-154 ◽  
Author(s):  
E. F. Adams ◽  
N. G. Coldham ◽  
V. H. T. James
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Human Breast Cancer ◽  
Transforming Growth Factor ◽  
Cancer Cell Line ◽  
Human Breast Cancer Cell ◽  
Human Breast ◽  
Epidermal Growth ◽  
Mcf 7

ABSTRACT We have examined the direct effects of progestins, oestrogens, peptide hormones and growth factors on oestradiol-17β dehydrogenase (OE2DH) activity of cultures of the human breast cancer cell line MCF-7. Cells were cultured in the presence of steroid or peptide for 6 days, after which the number of cells was determined and cellular OE2DH activity assessed. Progesterone, 6α-methyl-17α-hydroxyprogesterone acetate, norethisterone and d(−)-norgestrel all profoundly inhibited cell mitosis and stimulated reductive (oestrone→oestradiol-17β) and oxidative (oestradiol-17β→oestrone) OE2DH activity. Both oestrone and oestradiol-17β directly stimulated reductive OE2DH activity, but had no effect on the oxidative direction. Oestradiol-17β stimulated cell growth only in phenolred free culture medium. Ovine prolactin, LH, epidermal growth factor and transforming growth factor did not alter OE2DH activity but small stimulatory effects on the growth of MCF-7 cells were exerted by prolactin and a combination of transforming growth factor with epidermal growth factor. It is concluded that these results may explain, at least in part, the alterations in mitotic activity and tissue oestradiol-17β levels observed in breast tissue during varying physiological and pathological conditions, such as during the menstrual cycle and in breast cancers. J. Endocr. (1988) 118, 149–154

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