Mechanisms of autoinhibition and STI-571/imatinib resistance revealed by mutagenesis of BCR-ABL

Cell. 2003 Mar 21;112(6):831-43. doi: 10.1016/s0092-8674(03)00190-9.

Abstract

The Bcr-Abl fusion protein kinase causes chronic myeloid leukemia and is targeted by the signal transduction inhibitor STI-571/Gleevec/imatinib (STI-571). Sequencing of the BCR-ABL gene in patients who have relapsed after STI-571 chemotherapy has revealed a limited set of kinase domain mutations that mediate drug resistance. To obtain a more comprehensive survey of the amino acid substitutions that confer STI-571 resistance, we performed an in vitro screen of randomly mutagenized BCR-ABL and recovered all of the major mutations previously identified in patients and numerous others that illuminate novel mechanisms of acquired drug resistance. Structural modeling implies that a novel class of variants acts allosterically to destabilize the autoinhibited conformation of the ABL kinase to which STI-571 preferentially binds. This screening strategy is a paradigm applicable to a growing list of target-directed anti-cancer agents and provides a means of anticipating the drug-resistant amino acid substitutions that are likely to be clinically problematic.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Amino Acid Substitution
  • Antineoplastic Agents / pharmacology*
  • Benzamides
  • Drug Resistance, Neoplasm / genetics*
  • Enzyme Inhibitors / pharmacology*
  • Genetic Variation
  • Humans
  • Imatinib Mesylate
  • Inhibitory Concentration 50
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / enzymology
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed*
  • Piperazines / pharmacology*
  • Point Mutation
  • Protein Conformation
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Protein-Tyrosine Kinases / genetics
  • Pyrimidines / pharmacology*

Substances

  • Antineoplastic Agents
  • Benzamides
  • Enzyme Inhibitors
  • Piperazines
  • Pyrimidines
  • Imatinib Mesylate
  • Protein-Tyrosine Kinases