Slowed Signaling Stumps Tumors — Research by Drs. Jonathan Backer, Hashem Dbouk, and collaborators at the Medical Research Council Laboratory of Molecular Biology, in Cambridge, UK, may reveal a novel target for anti-cancer drugs. The scientists found a method for blocking a specific enzyme, PI3Kβ, which is known to promote tumor formation. PI3Kβ can be activated by receptor tyrosine kinases and by G-protein coupled receptors (GPCRs), but the mechanism of GPCR activation was unknown. The researchers identified the region of PI3Kβ required for its activation by GPCRs. Expression of a mutant PI3Kβ that cannot be activated by GPCRs, or treatment of cells with a peptide inhibitor of PI3Kβ activation, prevented control cells from becoming cancerous, and prevented the invasion of tumor cells in an in vitro metastasis assay. The data suggest that inhibition of GPCR signaling may provide a novel approach to the treatment of some cancers. Dr. Backer is a professor of molecular pharmacology. Dr. Dbouk is a recently graduated Ph.D. student in Dr. Backer’s lab. The study was featured on the cover of the December 4, 2012 issue of Science Signaling.
Posted on: Thursday, January 17, 2013