Growth factors and cytokines in health and disease. Breast cancer

Abstract. Polypeptide growth factors and their cognate receptors are involved in the proliferation of normal and transformed cells (Aaronson, 1991). It is widely accepted that tumor cells are less dependent than nontransformed cells of exogenous growth factors due to their ability to synthesize and respond to endogenous growth regulatory molecules. Most studies that examine the role of these growth factor/receptor pathways in tumor cells have used cellular proliferation as an endpoint. More recent experimental data argue that these biochemical systems are also important for the interaction of tumor epithelium with stromal elements and extracellular matrices thus allowing for the maintenance of the tumorigenic state. A large body of work has examined the role of EGF-like peptides, transforming growth factor (TGF) β, and the insulin-like growth factors (IGFs) on breast carcinoma cells. The prominent aspects of this work with its potential clinical implications will be reviewed next.