1Wolfson Institute for Biomedical Research, London WC1E 6BT, United Kingdom 2Institute of Molecular Biology and Genetics, Kyiv 143, Ukraine 3Ludwig Institute for Cancer Research, London W1W 7BS, United Kingdom
Abstract. Cellular functions are controlled by a network of signalling pathways, which allow cells to interact with and respond to their external environment. These pathways are mediated by proteins that activate signalling cascades in response to extracellular stimuli. One such protein is phosphoinositide 3-kinase (PI3K), a lipid kinase which exists in a number of different isoforms and which participates in the modification of phospholipids. These secondary messengers are involved in signalling pathways which regulate cell growth, proliferation, differentiation, cytoskeletal rearrangements, metabolic control, vesicular transport, membrane trafficking and apoptosis. Dysregulation of these signalling cascades can lead to abnormal cell cycle progression, altered cell mobility and adhesion properties, induction of angiogenesis and inhibition of apoptosis. The involvement of PI3K and the products of its activity in these processes points to a role for PI3K in a number of pathological disorders, including cancer.
Key Words: phospholipids, phosphoinositide 3-kinase, second messangers, signal transduction, cancer.
