Potent and specific PI3K inhibitor;LY 294002 is a potent and specific cell-permeable inhibitor of phosphatidylinositol 3-kinase (PI 3-kinase). In in vitro assays using purified PI 3-kinase, LY 294002 displays an IC50 of 1.4 µM and inhibits all isoforms equally. Other kinases such as PKC, PKA, MAP kinase, S6 kinase, EGF receptor tyrosine kinase, c-src kinase, PI 4-kinase, diacylglycerol kinase or rabbit kidney ATPase are not inhibited at 50 µM. In intact neutrophils stimulated with fMet-Leu-Phe, it completely abolished PI 3-kinase activity at 50 µM without cell toxicity. It induces apoptosis in many cell types by blocking the PI3-K/Akt anti-apoptotic pathway. PI 3-Kinase inhibitors have also been used in conjunction with nicotinamide to mature mouse embryonic stem cell-derived insulin-producing cells. LY 294002 is a useful tool for identifying cellular events which are regulated by the PI3-K/Akt axis. |