January 1, 2016
th a ViewLux uHTS Microplate Imager (PerkinElmer). Follow-up assays were performed in black 384-well plates (Greiner) in 20 ¾L of enzyme buffer to which compounds were added in dose-response with an HP D300 digital dispenser (Hewlett-Packard), followed by addition of 20 ¾L of substrate buffer. Plates were incubated at room temperature (25 °C) and read at 0 and 20 minutes with a Spectramax M5 pl;Page 1. Š 201 6 Nature America, Inc. All rights reserved. 452 nature chemical biology | vol 12 | June 2016 | www.nature.com/naturechemicalbiology ARTICLE published online: 25 april 2016 | doi: 10.1038/nchembio.2070 One
Serine is both a proteinogenic amino acid and the source of one-carbon units essential for _de novo_ purine and deoxythymidine synthesis. In the canonical pathway of glucose-derived serine synthesis, _Homo sapiens_ phosphoglycerate dehydrogenase (PHGDH) catalyzes the first, rate-limiting step. Genetic loss of PHGDH is toxic toward PHGDH-overexpressing breast cancer cell lines even in the presence of exogenous serine. Here, we used a quantitative high-throughput screen to identify small-molecule PHGDH inhibitors. These compounds reduce the production of glucose-derived serine in cells and suppress the growth of PHGDH-dependent cancer cells in culture and in orthotopic xenograft tumors. Surprisingly, PHGDH inhibition reduced the incorporation into nucleotides of one-carbon units from glucose-derived and exogenous serine. We conclude that glycolytic serine synthesis coordinates the use of one-carbon units from endogenous and exogenous serine in nucleotide synthesis, and we suggest that one-carbon unit wasting thus may contribute to the efficacy of PHGDH inhibitors _in vitro_ and _in vivo_.
Pacold, ME; Brimacombe, KR; Chan, SH; Rohde, JM; Lewis, CA; Swier, LJ; Possemato, R; Chen, WW; Sullivan, LB; Fiske, BP; Cho, S; Freinkman, E; Birsoy, K; Abu-Remaileh, M; Shaul, YD; Liu, CM; Zhou, M; Koh, MJ; Chung, H; Davidson, SM; Luengo, A; Wang, AQ; Xu, X; Yasgar, A; Liu, L; Rai, G; Westover, KD; Vander Heiden, MG; Shen, M; Gray, NS; Boxer, MB; Sabatini, DM;
Journal: Nat. Chem. Biol. Pages: 452-458