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Substrate-dependent effects of molecular-targeted anticancer agents on activity of organic anion transporting

Hiroyoshi Koide1, Masayuki Tsujimoto1, Ai Takeuchi1

  • 1a Department of Clinical Pharmacy , Faculty of Pharmaceutical Science, Kyoto Pharmaceutical University , Kyoto , Japan.

Insights

Molecular-targeted agents can have varying effects on Organic Anion-Transporting Polypeptide 1B1 (OATP1B1) activity. This study found that drug interactions with OATP1B1 are substrate-dependent, impacting drug metabolism and efficacy.

Area of Science:

  • Pharmacology
  • Drug Metabolism
  • Molecular Biology

Background:

  • Organic anion-transporting polypeptide 1B1 (OATP1B1) is crucial for the liver's uptake of many drugs.
  • Previous in vitro studies indicated that molecular-targeted agents do not consistently affect OATP1B1 activity.

Purpose of the Study:

  • To investigate whether the impact of molecular-targeted agents on OATP1B1 is dependent on the specific substrate.
  • To compare the effects of various molecular-targeted agents on OATP1B1-mediated uptake of different substrates.

Main Methods:

  • Utilized OATP1B1-transfected cells to assess drug uptake.
  • Compared the effects of several molecular-targeted agents on the OATP1B1-mediated transport of fluorescein (FL), 2',7'-dichlorofluorescein (DCF), atorvastatin, SN-38, and valsartan.

Main Results:

  • Most tested agents showed minimal impact on OATP1B1 activity.
  • Nilotinib and lenvatinib demonstrated moderate and strong inhibition, respectively.
  • Afatinib, ceritinib, and nintedanib exhibited substrate-dependent stimulation of OATP1B1, with effects varying by substrate type.

Conclusions:

  • The effects of certain molecular-targeted agents on OATP1B1 activity are substrate-dependent.
  • Using a single probe substrate to evaluate OATP1B1 activity with these agents may lead to inaccurate conclusions about drug interaction mechanisms.

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