Insulin-like growth factor-I receptor signal transduction and the Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) pathway

Biofactors. Jan-Feb 2009;35(1):76-81. doi: 10.1002/biof.20.

Abstract

The insulin-like growth factor IGF-I is an important fetal and postnatal growth factor, which is also involved in tissue homeostasis via regulation of proliferation, differentiation, and cell survival. To understand the role of IGF-I in the pathophysiology of a variety of disorders, including growth disorders, cancer, and neurodegenerative diseases, a detailed knowledge of IGF-I signal transduction is required. This knowledge may also contribute to the development of new therapies directed at the IGF-I receptor or other signaling molecules. In this review, we will address IGF-I receptor signaling through the JAK/STAT pathway in IGF-I signaling and the role of cytokine-induced inhibitors of signaling (CIS) and suppressors of cytokine signaling (SOCS). It appears that, in addition to the canonical IGF-I signaling pathways through extracellular-regulated kinase (ERK) and phosphatidylinositol-3 kinase (PI3K)-Akt, IGF-I also signals through the JAK/STAT pathway. Activation of this pathway may lead to induction of SOCS molecules, well-known feedback inhibitors of the JAK/STAT pathway, which also suppress of IGF-I-induced JAK/STAT signaling. Furthermore, other IGF-I-induced signaling pathways may also be modulated by SOCS. It is conceivable that the effect of these classical inhibitors of cytokine signaling directly affect IGF-I receptor signaling, because they are able to associate to the intracellular part of the IGF-I receptor. These observations indicate that CIS and SOCS molecules are key to cross-talk between IGF-I receptor signaling and signaling through receptors belonging to the hematopoietic/cytokine receptor superfamily. Theoretically, dysregulation of CIS or SOCS may affect IGF-I-mediated effects on body growth, cell differentiation, proliferation, and cell survival.

Publication types

  • Review

MeSH terms

  • Animals
  • Cytokines / metabolism
  • Humans
  • Janus Kinases / metabolism*
  • Models, Biological
  • Receptor, IGF Type 1 / metabolism*
  • STAT Transcription Factors / metabolism*
  • Signal Transduction*
  • Suppressor of Cytokine Signaling Proteins / metabolism

Substances

  • Cytokines
  • STAT Transcription Factors
  • Suppressor of Cytokine Signaling Proteins
  • Receptor, IGF Type 1
  • Janus Kinases