IGF-I has important roles in regulating growth and metabolism. Circulating IGF-I is bound to specific binding proteins (IGFBP-1 to -6), with hepatocytes containing IGF-I, IGFBP-1 and -2 mRNA. Although many hepatic proteins are regionally expressed in the liver acinus, no studies have reported zonation of IGF protein expression. In this study we investigated the pattern of hepatic mRNA for the I...

Insulin receptors and Type I insulinlike growth factor (IGF) receptors have a similar structure with a major binding subunit of Mr approximately 130,000 linked by disulfide bonds to other membrane proteins to form a Mr greater than 300,000 complex. Both insulin and Type I IGF receptors also interact with both insulin and IGF, although with different binding affinities. We used a panel of human ...

The insulin-like growth factor I receptor (IGF-IR) is involved in the control of breast cancer cell growth. The cytostatic activity of tamoxifen (Tam), a nonsteroidal antiestrogen, is partially mediated through interference with IGF-I-R-dependent proliferation, yet the effects of Tam on IGF-IR intracellular signaling have never been elucidated. Consequently, we investigated how Tam modifies the...

PURPOSE Numerous dietary factors elevate serum levels of insulin and insulin-like growth factor I (IGF-I), both potent prostate cancer mitogens. We tested whether varying dietary carbohydrate and fat, without energy restriction relative to comparison diets, would slow tumor growth and reduce serum insulin, IGF-I, and other molecular mediators of prostate cancer in a xenograft model. EXPERIMEN...

Human insulin-like growth factor I and II (IGF-I and IGF-II) in concentrations of 1-30 ng/ml, were shown to stimulate ornithine decarboxylase activity and [3H]thymidine incorporation in human SH-SY5Y neuroblastoma cells. Proliferation of these cells was also stimulated by IGF-I and II when added to RPMI 1640 medium, fortified with selenium, hydrocortisone, transferrin, and beta-estradiol. Label...

The insulin-like growth factors (IGFs) have been implicated in the autocrine and/or paracrine growth of a number of tumor types, including lung tumors. Importantly, insulin-like growth factor-binding proteins (IGFBPs), which both enhance and inhibit the physiological and biological actions of the IGFs, have been shown to be secreted in vitro by a wide range of tumors. In particular, IGFBP-2 is ...

BACKGROUND Insulin-like growth factor-I (IGF-I) is a potent mitogen. IGF-I and its main binding protein, IGF binding protein-3 (IGFBP-3), and their polymorphisms have been investigated in relation to risk of many cancers, but not esophageal adenocarcinoma. MATERIALS AND METHODS We used data and specimens from a longitudinal study of persons with Barrett's esophagus (n=344; median, 5.4 years f...

Elevated levels of urokinase plasminogen activator-1 (uPA) and the insulin-like growth factor-I receptor (IGF-IR) are associated with breast cancer recurrence and decreased survival. It is possible that activation of IGF-IR and elevations in uPA are mechanistically linked. Our laboratory recently showed that insulin-like growth factor-I (IGF-I) induces uPA protein and mRNA in the breast cancer ...

We compared the anabolic effects of recombinant human insulin-like growth factor I (rhIGF-I, 2.5 mg/kg) and equimolar amounts of rhIGF-I prebound to rhIGF binding protein-3 (rhIGF-I/BP-3) coinfused continuously with total parenteral nutrition (TPN) solution in dexamethasone (Dex, 70 microg/day ip)-treated male rats for 6 days. The four TPN groups included control, Dex, Dex + IGF-I, and Dex+IGF-...