The IGF-I receptor (IGF-IR) has been studied as an anti-cancer target. However, monotherapy trials with IGF-IR targeted antibodies or with IGF-IR specific tyrosine kinase inhibitors have, overall, been very disappointing in the clinical setting. This review discusses potential reasons why IGF-I R targeted therapy fails to inhibit growth of human cancers. It has become clear that intracellular s...

The supposed immunogenic character of glioma cells transfected with antisense IGF-I-Receptor (IGF-I-R) expression vector was tested for the presence of MHC-I currently present in cells of IGF-I antisense type. C6 rat glioma cell line was comparatively transfected in vitro with IGF I antisense (pMT-Anti-IGF I) or IGF I Receptor antisense (pMT-Anti-IGF I R) expression vectors. The wild and transf...

Insulin-like growth factor (IGF) I is a polypeptide hormone important in normal growth and development. Although IGF-I is a mitogen for many cancer cell lines, previous work has suggested that autocrine production of IGF-I is uncommon in cancers of epithelial origin. In this study, expression of IGF-I, its binding proteins, and its receptor were examined in ovarian cancer cell lines and tissues...

The insulin-like growth factor-I receptor (IGF-IR) is involved in tumorigenesis. The aim of the present study was to investigate whether the IGF-IR is a physiological target for p53 in osteosarcoma cells. The p53-induced regulation of IGF-IR levels was studied in a tetracycline-regulated expression system. When expressed in Saos-2, osteosarcoma cells that lack p53, wild-type p53 decreased, wher...

Insulin-like growth factor I and II (IGF-I and IGF-II) associate with specific IGF binding proteins (IGFBPs) present in plasma and extracellular fluids that can modulate the anabolic effects of these peptides. IGF-I has been shown to increase IGFBP concentrations in vivo and in vitro, but the mechanism and significance of this action are unknown. We examined these issues using normal and simian...

Insulin-like growth factor-I (IGF-I) is produced in the liver and other peripheral tissues in response to growth hormone (GH) stimuli. IGF-I regulates diverse physiological functions in an autocrine and/or paracrine manner. IGF-I and IGF-I receptor (type-I receptor) are expressed in human and rat pituitary glands. However, the cell types of IGF-I-expressing cells and target cells of IGF-I in th...

OBJECTIVE To investigate the immunohistochemical localization of insulin-like growth factor 1 (IGF-1) and IGF-1 receptor (IGF-1R) in archival specimens of sporadic schwannoma. METHOD This study retrospectively analysed the immunolocalization of IGF-1 and IGF-1R in schwannoma specimens collected from all patients with sporadic schwannoma that were treated by two institutions in Japan. The stud...

Specific binding of IGF-binding protein (IGFBP)-3 was shown to be present in the isolated, beating rat heart. The uptake of perfused (125)I-labeled IGF-I in the beating heart was decreased to 9% by blocking IGF-I binding sites with the IGF-I analog Long R(3) (LR(3)) IGF-I. When LR(3) was perfused with complexes of (125)I-IGF-I. IGFBP-3, uptake of (125)I-IGF-I was decreased to 41%, which was sig...

Pancreatic cancer is one of the most lethal malignant tumors. Insulin-like growth factor (IGF)-I receptor (IGF-Ir) signaling is required for maintenance of growth and tumorigenicity of many tumors, but this pathway has not been well studied in pancreatic cancer. We have shown previously successful therapy in colorectal and lung cancer xenograft models using recombinant adenoviruses expressing d...