[32] Use of variant cell lines and cell hybrids for the study of hormone and growth factor action

Publisher Summary This chapter describes methods for isolating variant cell lines having altered responses to polypeptide hormones and growth factors, and methods for somatic cell hybridization that can be used for gene mapping and complementation analysis. Some recent applications of these techniques to the study of growth factors are also reviewed in the chapter. It has become evident in the past few years that the receptors for a number of polypeptide growth factors, including insulin, insulin-like growth factor epidermal growth factor, and platelet-derived growth factor, each possess a tyrosine-specific protein kinase activity. However, the biological effects of these growth factors vary considerably. In particular, the synergistic effects of insulin and insulin-like growth factors in combination with PDGF, as well as the possible differences in their temporal sequence of action, suggest that there must be some differences in the pathway of action of the different growth factors.