Cited by 157Drug Transport and Resistance MechanismsBarrier Structure and Function StudiesPharmacogenetics and Drug Metabolism

The Inhibitor Ko143 Is Not Specific for ABCG2

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Weidner, Lora D., Zoghbi, Sami S., Lu, Shuiyu, Shukla, Suneet, Ambudkar, Suresh V., Pike, Victor W., Mulder, Jan, Gottesman, Michael M. +2 more·2015·The Journal of Pharmacology and Experimental Therapeutics

Abstract

Imaging ATP-binding cassette (ABC) transporter activity in vivo with positron emission tomography requires both a substrate and a transporter inhibitor. However, for ABCG2, there is no inhibitor proven to be specific to that transporter alone at the blood-brain barrier. Ko143 [[(3S,6S,12aS)-1,2,3,4,6,7,12,12a-octahydro-9-methoxy-6-(2-methylpropyl)-1,4-dioxopyrazino[1',2':1,6]pyrido[3,4- b]indole-3-propanoic acid 1,1-dimethylethyl ester], a nontoxic analog of fungal toxin fumitremorgin C, is a potent inhibitor of ABCG2, although its specificity in mouse and human systems is unclear. This study examined the selectivity of Ko143 using human embryonic kidney cell lines transfected with ABCG2, ABCB1, or ABCC1 in several in vitro assays. The stability of Ko143 in rat plasma was measured using high performance liquid chromatography. Our results show that, in addition to being a potent inhibitor of ABCG2, at higher concentrations (≥1 μM) Ko143 also has an effect on the transport activity of both ABCB1 and ABCC1. Furthermore, Ko143 was found to be unstable in rat plasma. These findings indicate that Ko143 lacks specificity for ABCG2 and this should be taken into consideration when using Ko143 for both in vitro and in vivo experiments.

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Crossref · 10.1124/jpet.115.225482

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Authors
Weidner, L. D., Zoghbi, S. S., Lu, S., Shukla, S., Ambudkar, S. V., Pike, V. W., Mulder, J., Gottesman, M. M., Innis, R. B., & Hall, M. D.
Affiliations
Karolinska Institutet (SE)
Venue
The Journal of Pharmacology and Experimental Therapeutics
Publisher
Elsevier BV
Published
2015-09
Volume
354
Issue
3
Pages
384-393
ISSN
0022-3565 (ISSN-L)
OpenAlex
W1905469811
Cited by
141
References
39
Citations by year
2026: 6 · 2025: 8 · 2024: 14 · 2023: 15 · 2022: 14 · 2021: 22 · 2020: 16 · 2019: 8 · 2018: 12 · 2017: 12 · 2016: 11 · 2015: 3
FWCI
5.82
Type
journal article
Language
en
Open access
Locations
  • Journal of Pharmacology and Experimental Therapeutics (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Karolinska Institutet
  • National Institutes of Health
  • National Institute of Mental Health
  • National Cancer Institute
Topics
  • Health Sciences › Medicine › Oncology › Drug Transport and Resistance Mechanisms
  • Life Sciences › Neuroscience › Neurology › Barrier Structure and Function Studies
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmacogenetics and Drug Metabolism
Keywords
Ko143, ABCG2, P-glycoprotein, MRP1, ABC transporter inhibitors, inhibitor selectivity, blood-brain barrier, plasma stability, positron emission tomography, drug transporters
MeSH terms
Adenosine, Animals, Biological Transport, Blood-Brain Barrier, Cell Line, Heterocyclic Compounds, 4 or More Rings, Humans, 3T3 Cells, Rats, Sprague-Dawley, ATP Binding Cassette Transporter, Subfamily B, ATP-Binding Cassette Transporters, Organic Anion Transporters, Multidrug Resistance-Associated Proteins, ATP-Binding Cassette, Sub-Family C Proteins, Cell Line, Tumor, Mice, Rats, Diketopiperazines, HEK293 Cells, MCF-7 Cells

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