Evidence map›Paper›PMID 25343249›Full record

ArticlePloS one2014

Characterization of the commercially-available fluorescent chloroquine-BODIPY conjugate, LynxTag-CQGREEN, as a marker for chloroquine resistance and uptake in a 96-well plate assay.

Cheryl C Y Loh, Rossarin Suwanarusk, Yan Quan Lee, Kitti W K Chan, Kit-Ying Choy, Laurent Rénia, Bruce Russell, Martin J Lear, François H Nosten, Kevin S W Tan and 1 more

Abstract read
In one paragraph

Article in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Near Infrared Fluorophore-Tagged Chloroquine inMolecules (Basel, Switzerland) · 2018
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Cheryl C Y LohDepartment of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Rossarin SuwanaruskSingapore Immunology Network, Agency for Science Technology and Research, Biopolis, Singapore, Singapore.
Yan Quan LeeDepartment of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore.
Kitti W K ChanDepartment of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Kit-Ying ChoyDepartment of Applied Biology and Chemical Technology, The State Key Laboratory of Chirosciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, PR China.
Laurent RéniaSingapore Immunology Network, Agency for Science Technology and Research, Biopolis, Singapore, Singapore.
Bruce RussellDepartment of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Martin J LearDepartment of Chemistry, Graduate School of Science, Tohoku University, Aza Aramaki, Aoba-ku, Sendai, Japan.
François H NostenCentre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom; Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Centre for Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, United Kingdom.
Kevin S W TanDepartment of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore.
Larry M C ChowDepartment of Applied Biology and Chemical Technology, The State Key Laboratory of Chirosciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, PR China.

Funding

Wellcome Trust
6 · The paper itself

Abstract

Chloroquine was a cheap, extremely effective drug against Plasmodium falciparum until resistance arose. One approach to reversing resistance is the inhibition of chloroquine efflux from its site of action, the parasite digestive vacuole. Chloroquine accumulation studies have traditionally relied on radiolabelled chloroquine, which poses several challenges. There is a need for development of a safe and biologically relevant substitute. We report here a commercially-available green fluorescent chloroquine-BODIPY conjugate, LynxTag-CQGREEN, as a proxy for chloroquine accumulation. This compound localized to the digestive vacuole of the parasite as observed under confocal microscopy, and inhibited growth of chloroquine-sensitive strain 3D7 more extensively than in the resistant strains 7G8 and K1. Microplate reader measurements indicated suppression of LynxTag-CQGREEN efflux after pretreatment of parasites with known reversal agents. Microsomes carrying either sensitive- or resistant-type PfCRT were assayed for uptake; resistant-type PfCRT exhibited increased accumulation of LynxTag-CQGREEN, which was suppressed by pretreatment with known chemosensitizers. Eight laboratory strains and twelve clinical isolates were sequenced for PfCRT and Pgh1 haplotypes previously reported to contribute to drug resistance, and pfmdr1 copy number and chloroquine IC50s were determined. These data were compared with LynxTag-CQGREEN uptake/fluorescence by multiple linear regression to identify genetic correlates of uptake. Uptake of the compound correlated with the logIC50 of chloroquine and, more weakly, a mutation in Pgh1, F1226Y.

Indexed as

Adenosine TriphosphateAnimalsBiomarkersBoron CompoundsChloroquineDNA Copy Number VariationsDrug ResistanceFluorescent DyesGenes, ProtozoanInhibitory Concentration 50MibefradilMicrosomesMolecular Probe TechniquesParasitesPlasmodium falciparumPolymorphism, Genetic4,4-difluoro-4-bora-3a,4a-diaza-s-indaceneAdenosine TriphosphateBiomarkersBoron CompoundsChloroquineFluorescent DyesMibefradilVerapamil

Identifiers

PMID25343249
PMCPMC4208776

What OpenQuestion holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.