IGF signaling as a therapeutic target in pediatric solid tumors of the central and peripheral nervous system

Similar to many other growth factor systems, the IGF system consists of more than a single ligand interacting with a single receptor. There are three ligands (IGF-I, IGF-II and insulin) that interact with at least four receptors. In addition, the IGF system also involves six well-characterized binding proteins that regulate IGF action. Type I IGF receptor-mediated signaling plays a fundamental role in cell growth and malignant transformation and is an important mediator of anti-apoptotic signals. This review describes the roles of IGF signaling in childhood tumors of the CNS and PNS, including neuroblastoma, medulloblastoma, atypical teratoid/rhabdoid tumors and craniopharyngioma. Moreover, it describes strategies to disrupt the IGF signaling as a potential cancer therapy.