title: Development of a novel high-throughput screen and identification of small-molecule inhibitors of the Gα-RGS17 protein-protein interaction using AlphaScreen.
abstract: In this study, the authors used AlphaScreen technology to develop a high-throughput screening method for interrogating small-molecule libraries for inhibitors of the Gα(o)-RGS17 interaction. RGS17 is implicated in the growth, proliferation, metastasis, and the migration of prostate and lung cancers. RGS17 is upregulated in lung and prostate tumors up to a 13-fold increase over patient-matched normal tissues. Studies show RGS17 knockdown inhibits colony formation and decreases tumorigenesis in nude mice. The screen in this study uses a measurement of the Gα(o)-RGS17 protein-protein interaction, with an excellent Z score exceeding 0.73, a signal-to-noise ratio >70, and a screening time of 1100 compounds per hour. The authors screened the NCI Diversity Set II and determined 35 initial hits, of which 16 were confirmed after screening against controls. The 16 compounds exhibited IC(50) <10 µM in dose-response experiments. Four exhibited IC(50) values <6 µM while inhibiting the Gα(o)-RGS17 interaction >50% when compared to a biotinylated glutathione-S-transferase control. This report describes the first high-throughput screen for RGS17 inhibitors, as well as a novel paradigm adaptable to many other RGS proteins, which are emerging as attractive drug targets for modulating G-protein-coupled receptor signaling.
authors.affiliation: Division of Medicinal and Natural Products Chemistry, College of Pharmacy, University of Iowa, 115 South Grand Avenue, Iowa City, IA 52242, USA.
authors.forename: Duncan I
authors.initials: DI
authors.lastname: Mackie
authors.forename: David L
authors.initials: DL
authors.lastname: Roman
mesh_terms: D001667:Binding, Competitive; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D057166:High-Throughput Screening Assays; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy; D008297:Male; D010957:Plasmids; D011471:Prostatic Neoplasms / Q000188:drug therapy; D011485:Protein Binding / Q000187:drug effects*; D020710:RGS Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D059629:Signal-To-Noise Ratio; D054852:Small Molecule Libraries / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D014169:Transformation, Bacterial
chemical_list: D020710:RGS Proteins; C550555:RGS17 protein, human; D011994:Recombinant Proteins; D054852:Small Molecule Libraries; D019204:GTP-Binding Proteins