Identification of a Small-Molecule Inhibitor of Class Ia PI3Ks with Cell-Based Screening Original Research Article

The mammalian target of rapamycin (mTOR) signaling network is central to the regulation of cell growth in response to both growth factors and nutrients. We developed a high-throughput, cell-based assay to identify small-molecule modulators of the mTOR signaling network. One such compound, which we name quinostatin, potently inhibits this network by directly targeting the lipid-kinase activity of the catalytic subunits of class Ia PI3Ks. This study illustrates the power of unbiased, phenotypic screening as a means for illuminating cell circuitry, and resulted in the identification of a chemotype for selective inhibition of the class Ia PI3Ks.