Tyrosine kinase signalling in breast cancer - Epidermal growth factor receptor: convergence point for signal integration and diversification

Cross-communication between different signalling systems is critical for th e integration of multiple and changing environmental influences on individu al cells. The epidermal growth factor receptor (EGFR) has been identified a s a key element in the complex signalling network that is utilized by vario us classes of cell-surface receptors. This nonclassical mode of signalling system cross-talk, in distinction to receptor activation induced by cognate ligands, has been termed 'signal transactivation'. With the EGFR as the co nvergence point and distribution focus, this scenario may involve signals e mitted by other members of the tyrosine kinase family, cytokine receptors, ion channels, G-protein-coupled receptors and integrins.