Targeting Insulin Receptor in Breast Cancer Using Small Engineered Protein Scaffolds
| Autor: | Benjamin J. Hackel, Douglas Yee, Jie Ying Chan |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Scaffold protein Cancer Research endocrine system medicine.medical_treatment Breast Neoplasms Article Receptor IGF Type 1 03 medical and health sciences Mice 0302 clinical medicine Downregulation and upregulation Nuclear Matrix-Associated Proteins Antigens CD Insulin-Like Growth Factor II medicine Animals Humans Insulin-Like Growth Factor I Receptor Insulin-like growth factor 1 receptor Cell Proliferation biology Insulin Growth factor nutritional and metabolic diseases Receptors Somatomedin Molecular biology Xenograft Model Antitumor Assays Receptor Insulin Repressor Proteins Insulin receptor 030104 developmental biology Oncology 030220 oncology & carcinogenesis biology.protein Cancer research Signal transduction hormones hormone substitutes and hormone antagonists Protein Binding Signal Transduction |
| Zdroj: | Molecular cancer therapeutics. 16(7) |
| ISSN: | 1538-8514 |
| Popis: | Insulin receptor (InsR) and the type I insulin-like growth factor (IGF1R) are homologous receptors necessary for signal transduction by their cognate ligands insulin, IGF-I and IGF-II. IGF1R mAbs, intended to inhibit malignant phenotypic signaling, failed to show benefit in patients with endocrine-resistant tumors in phase III clinical trials. Our previous work showed that in tamoxifen-resistant cells, IGF1R expression was lacking, but InsR inhibition effectively blocked growth. In endocrine-sensitive breast cancer cells, insulin was not growth stimulatory, likely due to the presence of hybrid InsR/IGF1R, which has high affinity for IGF-I, but not insulin. Combination inhibition of InsR and IGF1R showed complete suppression of the system in endocrine-sensitive breast cancer cells. To develop InsR-binding agents, we employed a small protein scaffold, T7 phage gene 2 protein (Gp2) with the long-term goal of creating effective InsR inhibitors and diagnostics. Using yeast display and directed evolution, we identified three Gp2 variants (Gp2 #1, #5, and #10) with low nanomolar affinity and specific binding to cell surface InsR. These Gp2 variants inhibited insulin-mediated monolayer proliferation in both endocrine-sensitive and resistant breast cancer, but did not downregulate InsR expression. Gp2 #5 and Gp2 #10 disrupted InsR function by inhibiting ligand-induced receptor activation. In contrast, Gp2 #1 did not block InsR phosphorylation. Notably, Gp2 #1 binding was enhanced by pretreatment of cells with insulin, suggesting a unique receptor-ligand–binding mode. These Gp2 variants are the first nonimmunoglobulin protein scaffolds to target insulin receptor and present compelling opportunity for modulation of InsR signaling. Mol Cancer Ther; 16(7); 1324–34. ©2017 AACR. |
| Databáze: | OpenAIRE |
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