IGF-I receptor signalling in transformation and differentiation
- Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10th Street, 624 BLSB, Philadelphia, PA 19107, USA
- Dr Baserga r_baserga{at}lac.jci.tju.edu
- Accepted 9 January 2001
Abstract
The type 1 insulin-like growth factor receptor (IGF-IR) sends several signals, some of which are contradictory. When the concentrations of insulin receptor substrate 1 (IRS-1), a major substrate of the IGF-IR, are high, the signal is mitogenic, anti-apoptotic, and can even cause malignant transformation. However, in the absence of IRS-1, the IGF-IR sends a differentiation signal, which leads to granulocytic differentiation in haemopoietic cells. The mitogenic signal of the IGF-IR/IRS-1 combination depends largely, but not exclusively, on the activation of the phosphatidylinositol-3 kinase (PI3K).
