PMID- 18227510 OWN - NLM STAT- MEDLINE DCOM- 20080331 LR - 20220321 IS - 1091-6490 (Electronic) IS - 0027-8424 (Print) IS - 0027-8424 (Linking) VI - 105 IP - 6 DP - 2008 Feb 12 TI - The T790M mutation in EGFR kinase causes drug resistance by increasing the affinity for ATP. PG - 2070-5 LID - 10.1073/pnas.0709662105 [doi] AB - Lung cancers caused by activating mutations in the epidermal growth factor receptor (EGFR) are initially responsive to small molecule tyrosine kinase inhibitors (TKIs), but the efficacy of these agents is often limited because of the emergence of drug resistance conferred by a second mutation, T790M. Threonine 790 is the "gatekeeper" residue, an important determinant of inhibitor specificity in the ATP binding pocket. The T790M mutation has been thought to cause resistance by sterically blocking binding of TKIs such as gefitinib and erlotinib, but this explanation is difficult to reconcile with the fact that it remains sensitive to structurally similar irreversible inhibitors. Here, we show by using a direct binding assay that T790M mutants retain low-nanomolar affinity for gefitinib. Furthermore, we show that the T790M mutation activates WT EGFR and that introduction of the T790M mutation increases the ATP affinity of the oncogenic L858R mutant by more than an order of magnitude. The increased ATP affinity is the primary mechanism by which the T790M mutation confers drug resistance. Crystallographic analysis of the T790M mutant shows how it can adapt to accommodate tight binding of diverse inhibitors, including the irreversible inhibitor HKI-272, and also suggests a structural mechanism for catalytic activation. We conclude that the T790M mutation is a "generic" resistance mutation that will reduce the potency of any ATP-competitive kinase inhibitor and that irreversible inhibitors overcome this resistance simply through covalent binding, not as a result of an alternative binding mode. FAU - Yun, Cai-Hong AU - Yun CH AD - Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA. FAU - Mengwasser, Kristen E AU - Mengwasser KE FAU - Toms, Angela V AU - Toms AV FAU - Woo, Michele S AU - Woo MS FAU - Greulich, Heidi AU - Greulich H FAU - Wong, Kwok-Kin AU - Wong KK FAU - Meyerson, Matthew AU - Meyerson M FAU - Eck, Michael J AU - Eck MJ LA - eng SI - PDB/2JIT SI - PDB/2JIU SI - PDB/2JIV GR - R01 CA080942/CA/NCI NIH HHS/United States GR - R01 CA116020/CA/NCI NIH HHS/United States GR - CA080942/CA/NCI NIH HHS/United States GR - CA116020/CA/NCI NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20080128 PL - United States TA - Proc Natl Acad Sci U S A JT - Proceedings of the National Academy of Sciences of the United States of America JID - 7505876 RN - 0 (Enzyme Inhibitors) RN - 0 (Quinazolines) RN - 8L70Q75FXE (Adenosine Triphosphate) RN - EC 2.7.10.1 (ErbB Receptors) RN - S65743JHBS (Gefitinib) SB - IM MH - Adenosine Triphosphate/*metabolism MH - Animals MH - Crystallography, X-Ray MH - Drug Resistance/*genetics MH - Enzyme Inhibitors/pharmacology MH - ErbB Receptors/antagonists & inhibitors/chemistry/*genetics/metabolism MH - Gefitinib MH - Insecta MH - Kinetics MH - *Mutation MH - Protein Conformation MH - Quinazolines/pharmacology PMC - PMC2538882 COIS- Conflict of interest statement: M.J.E. and M.M. are consultants for and receive research funding from Novartis Institutes for Biomedical Research. EDAT- 2008/01/30 09:00 MHDA- 2008/04/01 09:00 PMCR- 2008/08/12 CRDT- 2008/01/30 09:00 PHST- 2008/01/30 09:00 [pubmed] PHST- 2008/04/01 09:00 [medline] PHST- 2008/01/30 09:00 [entrez] PHST- 2008/08/12 00:00 [pmc-release] AID - 0709662105 [pii] AID - 9160 [pii] AID - 10.1073/pnas.0709662105 [doi] PST - ppublish SO - Proc Natl Acad Sci U S A. 2008 Feb 12;105(6):2070-5. doi: 10.1073/pnas.0709662105. Epub 2008 Jan 28.