PDGF receptor signaling networks in normal and cancer cells.

For about four decades, platelet-derived growth factors (PDGF) and their receptors have been the subject of intense research, revealing their roles in embryo development and human diseases. Drugs such as imatinib, which selectively inhibit the tyrosine kinase activity of these receptors, have been approved for the treatment of cancers such as gastrointestinal stromal tumors and chronic eosinophilic leukemia. Today, the interest in these factors is still increasing in relationship with new potential clinical applications in cancer, stroke, fibrosis and infectious diseases. This review focuses on the mechanisms of PDGF receptor signaling, with an emphasis on pathways that are important for disease development. Of particular interest, recent studies revealed significant differences between normal and cancer cells regarding signal transduction by these growth factors.