title: Analysis of the structural basis of specificity of inhibition of the Abl kinase by STI571.
abstract: STI571, a selective inhibitor of Bcr-Abl, has been a successful therapeutic agent in clinical trials for chronic myelogenous leukemia. Chronic phase chronic myelogenous leukemia patients treated with STI571 have durable responses; however, most responding blast phase patients relapse despite continued therapy. Co-crystallization studies of Abl kinase and an STI571-related compound identify specific amino acid residues as critical to STI571 binding, one of which, T315, has been characterized as an acquired Thr to Ile mutation in relapsed patients. Other studies, however, suggest that mutations other than these predicted contact points are capable of conferring STI571 resistance in relapsed patients. Using a variety of models of STI571 binding to the Abl kinase, we have performed an extensive mutational analysis of sites that might alter the sensitivity of the Abl kinase to STI571. Although mutation of many of the predicted contact points between Abl and STI571 result in a kinase-inactive protein, additional mutations that render the Abl kinase less sensitive to STI571 demonstrate a broad range of possibilities for clinical resistance that are now becoming evident.
authors.affiliation: Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon 97201, USA.
authors.forename: Amie S
authors.initials: AS
authors.lastname: Corbin
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Buchdunger
authors.forename: Furet
authors.initials: F
authors.lastname: Pascal
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Druker
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D001549:Benzamides; D001665:Binding Sites; D003001:Cloning, Molecular; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D000068877:Imatinib Mesylate; D007700:Kinetics; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics; D008958:Models, Molecular; D010879:Piperazines / Q000494:pharmacology*; D017354:Point Mutation; D011487:Protein Conformation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D011743:Pyrimidines / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D012680:Sensitivity and Specificity; D013379:Substrate Specificity
chemical_list: D001549:Benzamides; D004791:Enzyme Inhibitors; D010879:Piperazines; D011743:Pyrimidines; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D000068877:Imatinib Mesylate; D000255:Adenosine Triphosphate; C426236:ARG tyrosine kinase; D011505:Protein-Tyrosine Kinases