Major Signaling Pathways Involved in Breast Cancer

Breast cancer is the leading cause of cancer-related mortality among women worldwide. Significant advancement has been made recently in delineating the cellular processes and signaling pathways involved in breast cancer. Cross-communication between different pathways allows cells to identify and respond appropriately to the extracellular environment. Cancer development is a gradual and complex process resulting from any disruption in these pathways that ultimately generates signals defining the required biological response. The epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases represents both key regulators of normal cellular development as well as critical players in the development of a variety of cancers including breast cancer. The aim of this book chapter is to give a broad overview of signal transduction networks such as Ras/Raf/MEK/ERK and the PI3K/AKT pathways that are controlled by the EGFR superfamily of receptors. The elucidation of these signaling pathways will further provide new insights in understanding the pathogenesis of breast cancer and targeting these pathways to combat against breast cancer development, progression, and metastasis.