IGF-II (E3F3N) Rabbit Monoclonal Antibody #40941

Insulin-like growth factor 2 (IGF-II, IGF-2) is a peptide growth factor with structural similarity to insulin and insulin-like growth factor 1 (IGF-I). IGF-II is reported to interact with multiple cell-surface receptors, including type 1 insulin-like growth factor receptor (IGF1R), insulin receptor A isoform (IR-A), and the structurally distinct type-2 IGF receptor (IGF2R) (1,2). Activation of IGF1R and IR-A by IGF-II promotes cell growth, proliferation, apoptosis, and metabolic signaling (3,4); binding of IGF-II to IGF2R (a.k.a. mannose 6-phosphate receptor) results in IGF-II internalization via receptor-mediated endocytosis, and subsequent transport to the lysosome for degradation (5). Serum IGF-II is generally found in complex with insulin-like growth factor binding proteins (IGFBPs), to which it binds with high affinity; this interaction functions to prolong the half-life of IGF-II in circulation (3). IGF-II plays a particularly crucial role in promoting embryonic fetal growth and development (6-9); in rodents, many of these functions are displaced by IGF-I during normal postnatal development, whereas in humans, IGF-II expression is more widely maintained (10). Binding of IGF-II to both IGF1R and IR-A has been shown to promote cancer progression, primarily through promoting cell proliferation and survival (11,12). Small molecules designed to block IGF-II activity are thus being pursued as therapeutic strategies for cancer treatment (13).