IGFBP1 (D4E9T) XP^® Rabbit mAb #31025

Insulin-like growth factor-binding proteins (IGFBPs) play an integral role in modifying insulin-like growth factor (IGF) actions in a wide variety of cell types. There are six known IGFBP family members (IGFBP1-6), which are structurally related, but encoded by distinct genes. IGFBPs have high affinity for IGFs; in some contexts, IGFBPs inhibit IGF actions by preventing access to IGF receptors, while in others they potentiate IGF actions by facilitating ligand-receptor interaction (1-3). IGFBP1 is produced primarily by the liver and secreted into circulation, and studies show its expression can be negatively regulated by insulin (4, 5). Notably, low levels of IGFBP1 were shown to predict the future onset of Type 2 diabetes (5). Reduced expression of IGFBP1 expression was also associated with tumor progression in breast cancer, prostate cancer, pancreatic cancer and colorectal cancer, possibly stemming from reduced inhibition of mitogenic IGF signaling (6-9). Notably however, other research studies have reported increased levels of IGFBP1 in selected tumor types; in human schwannoma, increased IGFBP1 was associated with stimulation of the integrin β1/FAK pathway, supporting the concept of IGF-independent signaling functions for selected IGFBPs (10,11).