Serum Factors Inhibit Melanoma Cell Surface Expression of Type I and Type II IGF Receptors
| Autor: | C Bellan, M Remacle-Bonnet, Jacques Marvaldi, J. Secchi, F Garrouste, Gilbert Pommier, José Luis |
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| Rok vydání: | 1996 |
| Předmět: |
Blotting
Western Cell Biology Binding Competitive Biochemistry Culture Media Serum-Free Receptor IGF Type 2 Cell Line Receptor IGF Type 1 medicine Humans Potency Binding site Receptor Melanoma Molecular Biology Binding Sites Affinity labeling Affinity Labels Blood Proteins Cell Biology medicine.disease Molecular biology Gene Expression Regulation Neoplastic medicine.anatomical_structure biology.protein Surface expression Antibody |
| Zdroj: | Journal of Receptors and Signal Transduction. 16:115-134 |
| ISSN: | 1532-4281 1079-9893 |
| DOI: | 10.3109/10799899609039944 |
| Popis: | We have identified one class of IGF-I-binding sites and two classes of IGF-II-binding sites at the surface of the melanoma cell line IGR39. By means of affinity labeling with 125I-IGF-I, 290-300 kDa form was characterized. Using 125I-IGF-II, a 270 kDa polypeptide was labeled, corresponding to the type II IGF receptor. In the two serials of experiments, the order of potency in inhibiting 125I-IGF-I or 125I-IGF-II labeling of IGF-related peptides and alpha IR3, an antibody directed against type I receptor alpha subunit, was the same as in competition experiments. When IGR39 cells were cultured in a serum-free medium, the number of both high affinity IGF-II and IGF-I binding sites was increased, by 8- and 5-fold respectively, without any significant change in Kd values. In both culture conditions, we found IGFBP-2, -3 -4 and a 30 kDa form which Mr was consistent with IGFBP-5 or -6. Except for IGFBP-2, the amount of secreted IGFBPs was modified depending on culture conditions: in conditioned medium from cells cultured with 10% FCS, the amount of IGFBP-3 or -4 was higher, and the amount of the 30 kDa IGFBP was lower when compared to conditioned medium from cells cultured in serum-free medium. |
| Databáze: | OpenAIRE |
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