Abstract
The success of Imatinib (IM) therapy in chronic myeloid leukemia (CML) is compromised by the development of IM resistance and by a limited IM effect on hematopoietic stem cells. Danusertib (formerly PHA-739358) is a potent pan-aurora and ABL kinase inhibitor with activity against known BCR-ABL mutations, including T315I. Here, the individual contribution of both signaling pathways to the therapeutic effect of Danusertib as well as mechanisms underlying the development of resistance and, as a consequence, strategies to overcome resistance to Danusertib were investigated. Starting at low concentrations, a dose-dependent inhibition of BCR-ABL activity was observed, whereas inhibition of aurora kinase activity required higher concentrations, pointing to a therapeutic window between the two effects. Interestingly, the emergence of resistant clones during Danusertib exposure in vitro occurred considerably less frequently than with comparable concentrations of IM. In addition, Danusertib-resistant clones had no mutations in BCR-ABL or aurora kinase domains and remained IM-sensitive. Overexpression of Abcg2 efflux transporter was identified and functionally validated as the predominant mechanism of acquired Danusertib resistance in vitro. Finally, the combined treatment with IM and Danusertib significantly reduced the emergence of drug resistance in vitro, raising hope that this drug combination may also achieve more durable disease control in vivo.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP Binding Cassette Transporter, Subfamily G, Member 2
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ATP-Binding Cassette Transporters / antagonists & inhibitors
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ATP-Binding Cassette Transporters / genetics*
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ATP-Binding Cassette Transporters / metabolism
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Apoptosis / drug effects
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Aurora Kinases
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Benzamides / pharmacology*
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Cell Differentiation / drug effects
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Cell Line, Tumor
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Cell Proliferation / drug effects
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Clone Cells
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Drug Resistance, Neoplasm / drug effects*
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Drug Resistance, Neoplasm / genetics
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Drug Synergism
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Fusion Proteins, bcr-abl / antagonists & inhibitors
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Fusion Proteins, bcr-abl / metabolism*
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Gene Expression Regulation, Leukemic / drug effects
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Hematopoietic Stem Cells / drug effects
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Hematopoietic Stem Cells / pathology
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Humans
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Imatinib Mesylate
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Leukemia, Myelogenous, Chronic, BCR-ABL Positive / enzymology
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Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics
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Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology
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Mutation / genetics
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Neoplasm Proteins / antagonists & inhibitors
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Neoplasm Proteins / genetics*
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Neoplasm Proteins / metabolism
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Oligonucleotide Array Sequence Analysis
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Piperazines / pharmacology
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Polyploidy
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Protein Kinase Inhibitors / pharmacology*
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Protein Serine-Threonine Kinases / antagonists & inhibitors
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Protein Serine-Threonine Kinases / metabolism
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Pyrazoles / pharmacology*
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Pyrimidines / pharmacology
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Signal Transduction / drug effects
Substances
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ABCG2 protein, human
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ATP Binding Cassette Transporter, Subfamily G, Member 2
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ATP-Binding Cassette Transporters
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Benzamides
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Neoplasm Proteins
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Piperazines
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Protein Kinase Inhibitors
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Pyrazoles
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Pyrimidines
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Imatinib Mesylate
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Fusion Proteins, bcr-abl
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Aurora Kinases
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Protein Serine-Threonine Kinases
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danusertib