The insulin-like growth factor 1 (IGF-1 receptor (IGF-1R) is an essential regulator of cell growth and transformation. IGF-1 and IGF-2, via the IGF-1R, are potent breast cancer cell mitogens that promote the tumorigenic potential of cancer cells. The objective of this proposal is to develop reagents that block IGF-1R signaling. The insulin-like growth factor binding proteins (IGFBPs) bind IGF-1 and IGF-2 with higher affinities than the IGF-1R and serve to both protect the IGFs from degradation and reduce their delivery to the IGF-1R. The hypothesis of the proposal is that blockade of IGF-1R activity can be accomplished by developing IGF antagonists based on the structure of the IGF binding domain on the IGFBPs. The goal of Aim 1 is to define the structure of the IGF-binding domain on rhIGFBP-2 using photoaffinity labeling and mass spectrometric analyses. To this end, IGF-1 derivatized with photactivatable groups within its IGFBP-binding domain will be synthesized. This will allow the precise identification of the sites of interaction between rhIGFBP-2 and IGF-1. Based on these analyses, deletion, truncation and site-directed mutants of IGFBP-2 will be generated and tested for IGF binding activity.
Aim 2 will characterize the structure and function of a 15.8 kDa fragment of IGFBP-2. The goal of Aim 3 is to examine the mechanism responsible for IGFBPP-2 inhibition of IGF action. The goal of Aim 4 is to employ phage display to screen libraries for peptides having a high affinity for the IGFBP-binding domain on IGF-1 as an alternative means of designing IGF antagonists.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA078887-02
Application #
6377218
Study Section
Metabolic Pathology Study Section (MEP)
Program Officer
Gallahan, Daniel L
Project Start
2000-04-01
Project End
2005-03-31
Budget Start
2001-04-01
Budget End
2002-03-31
Support Year
2
Fiscal Year
2001
Total Cost
$257,400
Indirect Cost
Name
Medical University of South Carolina
Department
Pharmacology
Type
Schools of Medicine
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Swain, Monalisa; Slomiany, Mark G; Rosenzweig, Steven A et al. (2010) High-yield bacterial expression and structural characterization of recombinant human insulin-like growth factor binding protein-2. Arch Biochem Biophys 501:195-200
Lucas Jr, J T; Salimath, B P; Slomiany, M G et al. (2010) Regulation of invasive behavior by vascular endothelial growth factor is HEF1-dependent. Oncogene 29:4449-59
Swain, Monalisa; Thirupathi, R; Krishnarjuna, B et al. (2010) Spontaneous and reversible self-assembly of a polypeptide fragment of insulin-like growth factor binding protein-2 into fluorescent nanotubular structures. Chem Commun (Camb) 46:216-8
Mulligan, Jennifer K; Day, Terry A; Gillespie, M Boyd et al. (2009) Secretion of vascular endothelial growth factor by oral squamous cell carcinoma cells skews endothelial cells to suppress T-cell functions. Hum Immunol 70:375-82