PathScan^® PDGFR Activity Assay: Phospho-PDGFR, Phospho-SHP2, Phospho-Akt, and Phospho-p44/42 MAPK (Erk1/2) Multiplex Western Detection Cocktail II #5304

Platelet-derived growth factor (PDGF) is a dimeric molecule that exists as homodimers or heterodimers of related polypeptide chains (A and B). Two types of PDGF receptors have been identified. The PDGF alpha-receptor binds all three isoforms with high affinity, whereas the beta-receptor binds only PDGF-BB with high affinity, PDGF-AB with low affinity and does not appear to bind PDGF-AA (1). PDGF exerts its stimulatory effects on cells by binding to these two related protein tyrosine kinase receptors. Ligand binding induces receptor dimerization and autophosphorylation, allowing binding and activation of cytoplasmic SH2-domain-containing signal transduction molecules. Thereby, a number of different signaling pathways are initiated, leading to cell growth, actin reorganization, migration and differentiation (2-4). In clinical studies, PDGF expression has been shown in a number of different solid tumors, from glioblastomas to prostate carcinomas. In these various tumor types, the biologic role of PDGF signaling can vary from autocrine stimulation of cancer cell growth to more subtle paracrine interactions involving adjacent stroma and even angiogenesis. Targeting PDGF signaling becomes an effective way for tumor treatment (5).