title: Several Bcr-Abl kinase domain mutants associated with imatinib mesylate resistance remain sensitive to imatinib.
abstract: Imatinib mesylate is a selective Bcr-Abl kinase inhibitor, effective in the treatment of chronic myelogenous leukemia. Most patients in chronic phase maintain durable responses; however, many in blast crisis fail to respond, or relapse quickly. Kinase domain mutations are the most commonly identified mechanism associated with relapse. Many of these mutations decrease the sensitivity of the Abl kinase to imatinib, thus accounting for resistance to imatinib. The role of other mutations in the emergence of resistance has not been established. Using biochemical and cellular assays, we analyzed the sensitivity of several mutants (Met244Val, Phe311Leu, Phe317Leu, Glu355Gly, Phe359Val, Val379Ile, Leu387Met, and His396Pro/Arg) to imatinib mesylate to better understand their role in mediating resistance. While some Abl mutations lead to imatinib resistance, many others are significantly, and some fully, inhibited. This study highlights the need for biochemical and biologic characterization, before a resistant phenotype can be ascribed to a mutant.
authors.affiliation: Oregon Health and Science University Cancer Institute, Portland, OR 97239, USA.
authors.forename: Amie S
authors.initials: AS
authors.lastname: Corbin
authors.forename: Paul
authors.initials: P
authors.lastname: La Rosée
authors.forename: Eric P
authors.initials: EP
authors.lastname: Stoffregen
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Druker
authors.forename: Michael W
authors.initials: MW
authors.lastname: Deininger
mesh_terms: D000818:Animals; D001549:Benzamides; D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D016044:Fusion Proteins, bcr-abl / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D000068877:Imatinib Mesylate; D051379:Mice; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense; D010879:Piperazines / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D011743:Pyrimidines / Q000494:pharmacology*; D012008:Recurrence; D014162:Transfection
chemical_list: D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D016044:Fusion Proteins, bcr-abl