Dataset Information

Targeting Insulin Receptor in Breast Cancer Using Small Engineered Protein Scaffolds.

ABSTRACT: 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.

SUBMITTER: Chan JY

PROVIDER: S-EPMC5518922 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Targeting Insulin Receptor in Breast Cancer Using Small Engineered Protein Scaffolds.

Chan Jie Ying JY Hackel Benjamin J BJ Yee Douglas D

Molecular cancer therapeutics 20170503 7

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-sen ...[more]

PMID: 28468775

Similar Datasets

Project description:Despite early detection through the use of mammograms and aggressive intervention, breast cancer (BC) remains a clinical dilemma. BC can resurge after >10 years of remission. Studies indicate that BC cells (BCCs) with self-renewal and chemoresistance could be involved in dormancy. The majority of studies use in vitro, two-dimensional (2-D) monolayer cultures, which do not recapitulate the in vivo microenvironment. Thus, to determine the effect of three-dimensional (3-D) microenvironment on BCCs, this study fabricated tissue engineering scaffolds made of poly (?-caprolactone) (PCL) having aligned or random fibers. Random and aligned fibers mimic, respectively, the random and highly organized collagen fibers found in the tumor extracellular matrix. Chemoresistant BCCs were obtained by treating with carboplatin. Western blot analysis of carboplatin resistant (treated) MDA-MB-231 (highly invasive, basal-like) and T47D (low-invasive, luminal) BCCs showed an increase in Bcl-2, Oct-4 and Sox-2, suggesting protection from apoptosis and increase in stem-like markers. Further studies with MDA-MB-231 BCCs seeded on the scaffolds showed little to no change in cell number over time for non-treated BCCs whereas on tissue culture polystyrene (TCP), non-treated BCCs displayed a significant increase in cell number at days 4 and 7 as compared to day 1 (p<0.05). Treated BCCs did not proliferate on TCP and the fibrous scaffolds. Little to no cyclin D1 was expressed for non-treated BCCs on TCP. On fibrous scaffolds, non-treated BCCs stained for cyclin D1 during the 7-day culture period. Treated BCCs expressed cyclin D1 on TCP and fibrous scaffolds during the 7-day culture period. Proliferation, viability and cell cycle analysis indicated that this 3-D culture prompted the aggressive BCCs to adopt a dormant phenotype, while the treated BCCs retained their phenotype. The findings indicate that random and aligned fibrous PCL scaffolds may provide a useful system to study how the 3-D microenvironment affects the behavior of BCCs.

Dataset Information

Targeting Insulin Receptor in Breast Cancer Using Small Engineered Protein Scaffolds.

Publications

Targeting Insulin Receptor in Breast Cancer Using Small Engineered Protein Scaffolds.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets