Cited by 55Drug Transport and Resistance MechanismsAntibiotic Resistance in BacteriaPharmacogenetics and Drug Metabolism

Screening Compounds with a Novel High-Throughput ABCB1-Mediated Efflux Assay Identifies Drugs with Known Therapeutic Targets at Risk for Multidrug Resistance Interference

Open access
Ansbro, Megan R., Shukla, Suneet, Ambudkar, Suresh V., Yuspa, Stuart H., Li, Luowei·2013·PLoS ONE

Abstract

ABCB1, also known as P-glycoprotein (P-gp) or multidrug resistance protein 1 (MDR1), is a membrane-associated multidrug transporter of the ATP-binding cassette (ABC) transporter family. It is one of the most widely studied transporters that enable cancer cells to develop drug resistance. Reliable high-throughput assays that can identify compounds that interact with ABCB1 are crucial for developing new therapeutic drugs. A high-throughput assay for measuring ABCB1-mediated calcein AM efflux was developed using a fluorescent and phase-contrast live cell imaging system. This assay demonstrated the time- and dose-dependent accumulation of fluorescent calcein in ABCB1-overexpressing KB-V1 cells. Validation of the assay was performed with known ABCB1 inhibitors, XR9576, verapamil, and cyclosporin A, all of which displayed dose-dependent inhibition of ABCB1-mediated calcein AM efflux in this assay. Phase-contrast and fluorescent images taken by the imaging system provided additional opportunities for evaluating compounds that are cytotoxic or produce false positive signals. Compounds with known therapeutic targets and a kinase inhibitor library were screened. The assay identified multiple agents as inhibitors of ABCB1-mediated efflux and is highly reproducible. Among compounds identified as ABCB1 inhibitors, BEZ235, BI 2536, IKK 16, and ispinesib were further evaluated. The four compounds inhibited calcein AM efflux in a dose-dependent manner and were also active in the flow cytometry-based calcein AM efflux assay. BEZ235, BI 2536, and IKK 16 also successfully inhibited the labeling of ABCB1 with radiolabeled photoaffinity substrate [(125)I]iodoarylazidoprazosin. Inhibition of ABCB1 with XR9576 and cyclosporin A enhanced the cytotoxicity of BI 2536 to ABCB1-overexpressing cancer cells, HCT-15-Pgp, and decreased the IC50 value of BI 2536 by several orders of magnitude. This efficient, reliable, and simple high-throughput assay has identified ABCB1 substrates/inhibitors that may influence drug potency or drug-drug interactions and predict multidrug resistance in clinical treatment.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1371/journal.pone.0060334

Cites

50 of 50 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Ansbro, M. R., Shukla, S., Ambudkar, S. V., Yuspa, S. H., & Li, L.
Affiliations
National Cancer Institute (US)
Corresponding author
Li, Luowei
Venue
PLoS ONE
Published
2013-04-10
Volume
8
Issue
4
Pages
e60334
ISSN
1932-6203 (ISSN-L)
OpenAlex
W1984802696
Cited by
54
References
50
Citations by year
2026: 2 · 2025: 3 · 2024: 6 · 2023: 3 · 2022: 4 · 2021: 1 · 2020: 5 · 2019: 2 · 2018: 3 · 2017: 4 · 2016: 3 · 2015: 9 · 2014: 6 · 2013: 3
FWCI
3.75
Type
journal article
Language
en
Open access
Locations
  • PLoS ONE (publishedVersion, public-domain)
  • Europe PMC (PubMed Central) (publishedVersion, other-oa)
  • PubMed Central (publishedVersion, public-domain)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • Figshare (submittedVersion, cc-by)
Funders
  • National Institutes of Health
  • National Cancer Institute
Topics
  • Health Sciences › Medicine › Oncology › Drug Transport and Resistance Mechanisms
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Medicine › Antibiotic Resistance in Bacteria
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmacogenetics and Drug Metabolism
Keywords
P-glycoprotein, multidrug resistance, high-throughput assay, ABC transporter inhibitors, drug-drug interactions, BEZ235, BI2536, ispinesib, photoaffinity labeling, drug resistance prediction
MeSH terms
Cell Line, Humans, Quinolines, Verapamil, Reproducibility of Results, Cyclosporine, Drug Resistance, Multiple, ATP Binding Cassette Transporter, Subfamily B, ATP Binding Cassette Transporter, Subfamily B, Member 1, High-Throughput Screening Assays

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review