Role of the IGF‐I receptor in the regulation of cell–cell adhesion: Implications in cancer development and progression

Abstract
The insulin‐like growth factor‐I receptor (IGF‐IR) is a ubiquitous multifunctional tyrosine kinase that has an important role in normal cell growth and development. However, abnormal stimulation of IGF‐IR signaling has been implicated in the development of different types of tumors. The strong antiapoptotic activity of IGF‐IR has been recognized as critical in IGF‐I‐dependent tumorigenesis, however, the impact of other IGF‐IR functions, such as regulation of cell–cell and cell–matrix adhesion are also increasingly acknowledged. Here, on the model of breast cancer cells, we discuss how IGF‐IR‐dependent regulation of intercellular adhesion may affect cell survival, resistance to antiestrogens, and invasion.