The hOCT1 SNPs M420del and M408V alter imatinib uptake and M420del modifies clinical outcome in imatinib-treated chronic myeloid leukemia

Blood. 2013 Jan 24;121(4):628-37. doi: 10.1182/blood-2012-01-405035. Epub 2012 Dec 5.


Although the prognosis of chronic myeloid leukemia (CML) patients treated with imatinib is good, many fail to develop an optimal response or lose one. This heterogeneity could be attributed to the presence of human organic cation transporter-1 (hOCT1) single nucleotide polymorphisms (SNPs). In the present study, we analyzed the effect of 23 hOCT1 SNPs on imatinib treatment outcome in newly diagnosed CML patients using MassARRAY sequencing and pyrosequencing. The only SNP associated with outcome was M420del (rs35191146), with patients with the M420del demonstrating an increased probability of imatinib treatment failure. In CML cell lines transfected with M420del and/or M408V, M420del significantly decreased imatinib uptake, but this effect was countered if the M408V (rs628031) SNP was also present. A similar effect was seen for the uptake of the hOCT1 substrates TEA(+) and ASP(+). Finally, apparent hOCT1 mRNA levels were studied using both our earlier primers covering the M420del and another set that did not. Different mRNA expression was observed, explaining the disparity in published data on the prognostic importance of hOCT1 mRNA and highlighting the importance of avoiding common SNP sites in primer design. These data demonstrate that the common M420del SNP can modulate the outcome of imatinib treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alleles
  • Antineoplastic Agents / pharmacokinetics
  • Antineoplastic Agents / therapeutic use*
  • Benzamides
  • Cell Line, Tumor
  • Female
  • Gene Expression
  • Gene Expression Regulation, Leukemic
  • Genotype
  • Humans
  • Imatinib Mesylate
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / mortality
  • Male
  • Middle Aged
  • Models, Molecular
  • Organic Cation Transporter 1 / chemistry
  • Organic Cation Transporter 1 / genetics*
  • Organic Cation Transporter 1 / metabolism
  • Piperazines / pharmacokinetics
  • Piperazines / therapeutic use*
  • Polymorphism, Single Nucleotide*
  • Protein Conformation
  • Protein Kinase Inhibitors / pharmacokinetics
  • Protein Kinase Inhibitors / therapeutic use*
  • Pyrimidines / pharmacokinetics
  • Pyrimidines / therapeutic use*
  • Treatment Outcome
  • Young Adult


  • Antineoplastic Agents
  • Benzamides
  • Organic Cation Transporter 1
  • Piperazines
  • Protein Kinase Inhibitors
  • Pyrimidines
  • Imatinib Mesylate