Cultured human retinal pigment epithelial cells (RPE) secrete insulin-like growth factor binding proteins (IGFBPs), a family of polypeptides which modulate the actions of the insulin-like growth factors. RPE cells secrete two IGFBPs with Mr estimates of 34,000 and 46,000, respectively. Treatment of RPE cells with IGF-I markedly stimulated the secretion of the 46,000 Mr form. This stimulation oc...

Heparin-binding insulin-like growth factor 1 (HB-IGF-1) is a fusion protein of IGF-1 with the HB domain of heparin-binding epidermal growth factor-like growth factor. A single dose of HB-IGF-1 has been shown to bind specifically to cartilage and to promote sustained upregulation of proteoglycan synthesis in cartilage explants. Achieving strong integration between native cartilage and tissue-eng...

The present experiments were designed to test the role of insulin-like growth factor-related peptides (IGF-RPs) in hormonally stimulated N-nitrosomethylurea (NMU)-induced mammary tumor colony formation in soft agar. To evaluate production of IGF-RP by NMU cells, we tested the abilities of a monoclonal antibody directed against insulin-like growth factor I (alpha sm 1.20B) and of a polyclonal an...

The type I insulin-like growth factor receptor (IGF-IR) plays multiple roles in several cancers and increased circulating levels of insulin-like growth factor-I (IGF-I) are associated with increased risk of breast, colon, and prostate cancers. Because IGF-II and insulin signal via the insulin receptor (IR) to stimulate the growth of cancer cells, inhibition of IR might be necessary to totally d...

Serum insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein-3 (IGFBP-3), and a range of growth and nutritional variables were investigated in 62 infants with congenital heart disease and healthy controls. Infants with congenital heart disease were small, underweight, and had a reduced energy intake. Serum IGF-1 and IGFBP-3 concentrations were significantly reduced. Dec...

Insulin-like growth factor 1 (IGF-1) is a mitogen which plays a key role in regulating cell proliferation, differentiation, and apoptosis. It belongs to the family of proteins also composed of insulin-like growth factor 2 (IGF-2), two types of membrane receptors (IGF-1R and IGF-2R), 6 binding proteins (IGFBP 1-6), hydrolyzing proteases, and reactive molecules binding proteins, which regulate th...

Insulin-like growth factor-I (IGF-I) is essential for normal growth; igf-1 gene mutations are associated with extreme growth retardation in mice and, very rarely, in humans. The relative contributions of tissue vs. endocrine (hepatic) IGF-I to the regulation of growth has been a fundamental question. New gene targeting technologies are providing answers for these questions.

Insulin-like growth factor (IGF)-II is known to induce hypertrophy of isolated adult rat ventricular cardiomyocytes cultured in the absence of serum. However, it is not known how the growth factor exerts this hypertrophic effect. We show here that IGF-II induces hypertrophy of the cultured cardiomyocytes via two alternative pathways: (1) an IGF-I receptor-dependent pathway, or (2) a lysosome-de...