Transfection Assays With Allele-Specific Constructs

Functional Analysis of UDP-Glucuronosyltransferase Variants
  • Hideto Jinno
  • Nobumitsu Hanioka
  • Toshiko Tanaka-Kagawa
  • Yoshiro Saito
  • Jun-ichi Sawada
  • Shogo Ozawa
Part of the Methods in Molecular Biology™ book series (MIMB, volume 311)


Adverse drug reactions (ADRs) are a major clinical problem. A rapidly growing body of evidence suggests that genetic factors, at least in part, determine individual susceptibility to ADRs. A large number of pharmacogenetic studies have identified a number of polymorphisms as predictors of drug efficacy and/or adverse events. These candidate markers should be investigated further to ascertain the underlying mechanism of action, for example, changes in the kinetic parameters of an enzyme, or transcriptional activity of a promoter region. In this chapter, we describe a transient transfection assay for the functional characterization of naturally occurring variants of UDP-glucuronosyltransferase (UGT) 1A1. This phase II drug metabolizing enzyme is involved in the glucuronidation of SN-38, an active metabolite of the anti-cancer drug irinotecan. Single-nucleotide polymorphisms of the UGT1A1 gene have been correlated to irinotecan-induced ADRs. Variant UGT1A1s are heterologously expressed in COS-1 cells and characterized in terms of the level of protein expression and enzyme kinetics.

Key Words

UDP-glucuronosyltransferase 1A1 single-nucleotide polymorphism adverse drug reactions SN-38 glucuronidation kinetic analysis 


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Copyright information

© Humana Press Inc., Totowa, NJ 2005

Authors and Affiliations

  • Hideto Jinno
    • 1
  • Nobumitsu Hanioka
    • 2
  • Toshiko Tanaka-Kagawa
    • 1
  • Yoshiro Saito
    • 3
  • Jun-ichi Sawada
    • 3
  • Shogo Ozawa
    • 4
  1. 1.Division of Environmental ChemistryNational Institute of Health SciencesTokyoJapan
  2. 2.Laboratory of Health Chemistry, Faculty of Pharmaceutical SciencesOkayama UniversityTokyoJapan
  3. 3.Division of Biochemistry and ImmunochemistryNational Institute of Health SciencesTokyoJapan
  4. 4.Division of PharmacologyNational Institute of Health SciencesTokyoJapan

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