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Muckelbauer J, Sack JS, Ahmed N, Burke J, Chang CY, Gao M, Tino J, Xie D, Tebben AJ. X-Ray Crystal Structure of Bone Marrow Kinase in the X Chromosome: A Tec Family Kinase. Chem Biol Drug Des 2011; 78:739-48. [DOI: 10.1111/j.1747-0285.2011.01230.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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52
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Rothweiler U, Åberg E, Johnson KA, Hansen TE, Jørgensen JB, Engh RA. p38α MAP kinase dimers with swapped activation segments and a novel catalytic loop conformation. J Mol Biol 2011; 411:474-85. [PMID: 21699901 DOI: 10.1016/j.jmb.2011.06.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Revised: 06/06/2011] [Accepted: 06/08/2011] [Indexed: 01/08/2023]
Abstract
Many protein kinase functions, including autophosphorylation in trans, require dimerization, possibly by activation segment exchange. Such dimers have been reported for a few autophosphorylating protein kinases, but not for mitogen-activated protein kinases (MAPKs). Activation of MAPKs proceeds not only via the well-characterized action of dual T/Y specificity MAPK kinases, phosphorylating both residues of the MAPK TxY activation loop motif, but also via a noncanonical activation pathway triggered by phosphorylation at Tyr323 and homodimerization. Here, we report the 2. 7-Å-resolution structure of p38α MAPK from Salmo salar in a novel domain-swapped homodimeric form. The tyrosines of the conserved sequence YxAPE anchor the swapped activation segments in a configuration suitable for autophosphorylation in trans and provide a model for the noncanonical pathway. In the dimer, a structural unit containing Tyr323 is formed at a dimerization contact region that stabilizes the HRD catalytic loop in a unique inactive geometry. This feature is consistent with the requirement of Tyr323 phosphorylation for the initiation of the noncanonical pathway. Despite the interacting surface of more than 2600 Å(2), the dimer is not obligate, as gel filtration shows the dimerization to occur only at relatively high concentrations. The transition from monomer to dimer involves a relatively simple hinged displacement of helix EF and adjacent residues. Thus, dimer formation is likely to be transient, compatible with functional requirements for autophosphorylation, allowing further modulation, for example, by scaffolding mechanisms.
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Affiliation(s)
- Ulli Rothweiler
- Department of Chemistry, The Norwegian Structural Biology Centre, University of Tromsø, 9037 Tromsø, Norway
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53
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Amrein PC, Attar EC, Takvorian T, Hochberg EP, Ballen KK, Leahy KM, Fisher DC, LaCasce AS, Jacobsen ED, Armand P, Hasserjian RP, Werner L, Neuberg D, Brown JR. Phase II study of dasatinib in relapsed or refractory chronic lymphocytic leukemia. Clin Cancer Res 2011; 17:2977-86. [PMID: 21402714 PMCID: PMC3108904 DOI: 10.1158/1078-0432.ccr-10-2879] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE Chronic lymphocytic leukemia (CLL) cells treated with dasatinib in vitro undergo apoptosis via inhibition of Lyn kinase. Thus, in this study we tested the activity of dasatinib in patients with relapsed CLL. EXPERIMENTAL DESIGN Patients were eligible for this phase II trial if they had documented CLL/SLL and had failed at least 1 prior therapy with a fludarabine-containing regimen and if they required therapy according to NCI-WG criteria. The starting dose of dasatinib was 140 mg daily. RESULTS Fifteen patients were enrolled, with a median age of 59 and a median of 3 prior regimens. All patients had received fludarabine, and 5 were fludarabine-refractory. Eleven of the 15 (73%) had high risk del(11q) or del(17p) cytogenetics. The primary toxicity was myelosuppression, with grade 3 or 4 neutropenia and thrombocytopenia in 10 and 6 patients, respectively. Partial responses by NCI-WG criteria were achieved in 3 of the 15 patients (20%; 90% CI: 6-44). Among the remaining 12 patients, 5 had nodal responses by physical exam, and 1 patient had a nodal and lymphocyte response but with severe myelosuppression. Pharmacodynamic studies indicated apoptosis in peripheral blood CLL cells within 3 to 6 hours after dasatinib administration, associated with downregulation of Syk (spleen tyrosine kinase) mRNA. CONCLUSIONS Dasatinib as a single agent has activity in relapsed and refractory CLL.
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MESH Headings
- Adult
- Aged
- Antineoplastic Agents/adverse effects
- Antineoplastic Agents/blood
- Antineoplastic Agents/pharmacokinetics
- Antineoplastic Agents/therapeutic use
- Dasatinib
- Drug Resistance, Neoplasm/drug effects
- Female
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/blood
- Leukemia, Lymphocytic, Chronic, B-Cell/diagnostic imaging
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Male
- Middle Aged
- Pyrimidines/adverse effects
- Pyrimidines/blood
- Pyrimidines/pharmacokinetics
- Pyrimidines/therapeutic use
- Radiography, Abdominal
- Recurrence
- Thiazoles/adverse effects
- Thiazoles/blood
- Thiazoles/pharmacokinetics
- Thiazoles/therapeutic use
- Tomography, X-Ray Computed
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Affiliation(s)
- Philip C. Amrein
- Massachusetts General Hospital Cancer Center, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | - Eyal C. Attar
- Massachusetts General Hospital Cancer Center, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | - Tak Takvorian
- Massachusetts General Hospital Cancer Center, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | - Ephraim P. Hochberg
- Massachusetts General Hospital Cancer Center, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | - Karen K. Ballen
- Massachusetts General Hospital Cancer Center, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | | | - David C. Fisher
- Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | - Ann S. LaCasce
- Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | - Eric D. Jacobsen
- Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | - Philippe Armand
- Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
| | | | - Lillian Werner
- Department of Biostatistics, Dana-Farber Cancer Institute, Boston, MA
| | - Donna Neuberg
- Department of Biostatistics, Dana-Farber Cancer Institute, Boston, MA
| | - Jennifer R. Brown
- Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Medicine, Harvard Medical School, Boston, MA
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54
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Amrein PC. The potential for dasatinib in treating chronic lymphocytic leukemia, acute myeloid leukemia, and myeloproliferative neoplasms. Leuk Lymphoma 2011; 52:754-63. [PMID: 21463117 DOI: 10.3109/10428194.2011.555890] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Dasatinib is a kinase inhibitor that inhibits BCR-ABL, Src family kinases, c-Kit, and platelet-derived growth factor receptor kinase. It is licensed for the first- and second-line treatment of chronic myeloid leukemia and second-line treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia on the basis of BCR-ABL inhibition, but the activity of dasatinib against additional molecular targets may enable treatment of other hematologic disorders. Potential targets for dasatinib in chronic lymphocytic leukemia (CLL) include Lyn (a Src family kinase), ABL, and the associated CD40 pathway. Although dasatinib monotherapy has modest clinical activity in CLL, ongoing studies are evaluating combination treatment. In acute myeloid leukemia (AML), FLT3, Lyn, c-Kit, and BCR-ABL are expressed in a subpopulation of patients. To date, clinical responses to dasatinib in patients with unselected AML have been mixed and larger studies are needed, particularly correlating clinical response to molecular markers. Imatinib has been used successfully to treat patients with chronic eosinophilic disorders with the FIP1L1-PDGFRA fusion kinase; limited clinical data indicate that dasatinib could be active in imatinib-resistant disease. Ongoing clinical studies should further define the value of dasatinib in these disorders.
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Affiliation(s)
- Philip C Amrein
- Hematology-Oncology, Massachusetts General Hospital, Boston, MA 02114, USA.
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Marcotte DJ, Liu YT, Arduini RM, Hession CA, Miatkowski K, Wildes CP, Cullen PF, Hong V, Hopkins BT, Mertsching E, Jenkins TJ, Romanowski MJ, Baker DP, Silvian LF. Structures of human Bruton's tyrosine kinase in active and inactive conformations suggest a mechanism of activation for TEC family kinases. Protein Sci 2010; 19:429-39. [PMID: 20052711 PMCID: PMC2866269 DOI: 10.1002/pro.321] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 12/11/2009] [Accepted: 12/14/2009] [Indexed: 12/20/2022]
Abstract
Bruton's tyrosine kinase (BTK), a member of the TEC family of kinases, plays a crucial role in B-cell maturation and mast cell activation. Although the structures of the unphosphorylated mouse BTK kinase domain and the unphosphorylated and phosphorylated kinase domains of human ITK are known, understanding the kinase selectivity profiles of BTK inhibitors has been hampered by the lack of availability of a high resolution, ligand-bound BTK structure. Here, we report the crystal structures of the human BTK kinase domain bound to either Dasatinib (BMS-354825) at 1.9 A resolution or to 4-amino-5-(4-phenoxyphenyl)-7H-pyrrolospyrimidin- 7-yl-cyclopentane at 1.6 A resolution. This data provides information relevant to the development of small molecule inhibitors targeting BTK and the TEC family of nonreceptor tyrosine kinases. Analysis of the structural differences between the TEC and Src families of kinases near the Trp-Glu-Ile motif in the N-terminal region of the kinase domain suggests a mechanism of regulation of the TEC family members.
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Affiliation(s)
- Douglas J Marcotte
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Yu-Ting Liu
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Robert M Arduini
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Catherine A Hession
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Konrad Miatkowski
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Craig P Wildes
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Patrick F Cullen
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Victor Hong
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Brian T Hopkins
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | | | - Tracy J Jenkins
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Michael J Romanowski
- Sunesis Pharmaceuticals, Inc.395 Oyster Point Boulevard, South San Francisco, California 94080
| | - Darren P Baker
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
| | - Laura F Silvian
- Biogen Idec, Inc., Drug Discovery Department12 Cambridge Center, Cambridge, Massachusetts 02142
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