Simplified schematic diagram of insulin-like growth factor (IGF) signaling

Simplified schematic diagram of insulin-like growth factor (IGF) signaling. IGF-I and IGF-II bind to IGF receptor (IGFR), a receptor tyrosine kinase (RTK), with high affinity resulting in phosphorylation of intracellular proteins including insulin receptor substrate (IRS). The signal is then conveyed to specific downstream effectors such as phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT/PKB), and mitogen-activated protein kinase (MAPK) pathways. These pathways play crucial roles in antiapoptosis as well as cell proliferation. Bioavailability of both IGFs is influenced by the presence of IGF binding proteins (IGFBP). New therapeutic agents such as AG1024 and gefitinib aim to block this signaling pathway at level of the receptor. Downstream targeting agents such as rapamycin, CCI-779, and RAD001 are also under investigation.

Publication

Liver Stem Cells and Molecular Signaling Pathways in Hepatocellular Carcinoma. (2007) Krit Kitisin, et al. Gastrointest Cancer Res. 2007 Jul-Aug;1(4 Suppl 2):S13-S21. Figure: F4. All organisms Drosophila melanogaster Homo sapiens

Disease mentions