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BioAssay: AID 679657

TP_TRANSPORTER: efflux in MRP8-1-expressing LLC-PK1 cells

MRP8 (ABCC11) is a recently identified cDNA that has been assigned to the multidrug resistance-associated protein (MRP) family of ATP-binding cassette transporters, but its functional characteristics have not been determined. Here we examine the functional properties of the protein using transfected LLC-PK1 cells. It is shown that ectopic expression of MRP8 reduces basal intracellular levels of more ..
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 Tested Compounds
 Tested Compounds
All(2)
 
 
Unspecified(2)
 
 
 Tested Substances
 Tested Substances
All(2)
 
 
Unspecified(2)
 
 
 Related BioAssays
 Related BioAssays
AID: 679657
Data Source: ChEMBL (836796)
Depositor Category: Other
BioAssay Version:
Deposit Date: 2013-05-16
Modify Date: 2013-11-17

Data Table ( Complete ):           All
Target
Sequence: RecName: Full=ATP-binding cassette sub-family C member 11; AltName: Full=Multidrug resistance-associated protein 8
Description ..   
Protein Family: ATP-binding cassette domain 2 of multidrug resistance-associated protein
Comment ..   

Gene:ABCC11     Related Protein 3D Structures     More BioActivity Data..
Tested Compounds:
Description:
Title: MRP8, ATP-binding cassette C11 (ABCC11), is a cyclic nucleotide efflux pump and a resistance factor for fluoropyrimidines 2',3'-dideoxycytidine and 9'-(2'-phosphonylmethoxyethyl)adenine.

Abstract: MRP8 (ABCC11) is a recently identified cDNA that has been assigned to the multidrug resistance-associated protein (MRP) family of ATP-binding cassette transporters, but its functional characteristics have not been determined. Here we examine the functional properties of the protein using transfected LLC-PK1 cells. It is shown that ectopic expression of MRP8 reduces basal intracellular levels of cAMP and cGMP and enhances cellular extrusion of cyclic nucleotides in the presence or absence of stimulation with forskolin or SIN-1A. Analysis of the sensitivity of MRP8-overexpressing cells revealed that they are resistant to a range of clinically relevant nucleotide analogs, including the anticancer fluoropyrimidines 5'-fluorouracil (approximately 3-fold), 5'-fluoro-2'-deoxyuridine (approximately 5-fold), and 5'-fluoro-5'-deoxyuridine (approximately 3-fold), the anti-human immunodeficiency virus agent 2',3'-dideoxycytidine (approximately 6-fold) and the anti-hepatitis B agent 9'-(2'-phosphonylmethoxynyl)adenine (PMEA) (approximately 5-fold). By contrast, increased resistance was not observed for several natural product chemotherapeutic agents. In accord with the notion that MRP8 functions as a drug efflux pump for nucleotide analogs, MRP8-transfected cells exhibited reduced accumulation and increased efflux of radiolabeled PMEA. In addition, it is shown by the use of in vitro transport assays that MRP8 is able to confer resistance to fluoropyrimidines by mediating the MgATP-dependent transport of 5'-fluoro-2'-deoxyuridine monophosphate, the cytotoxic intracellular metabolite of this class of agents, but not of 5'-fluorouracil or 5'-fluoro-2'-deoxyuridine. We conclude that MRP8 is an amphipathic anion transporter that is able to efflux cAMP and cGMP and to function as a resistance factor for commonly employed purine and pyrimidine nucleotide analogs.
Categorized Comment
ChEMBL Assay Type: Functional

ChEMBL Assay Data Source: TP-search Transporter Database

ChEMBL Assay Test Type: In vitro

ChEMBL Assay Cell Type: LLC-PK1 (Renal epithelial cells)

ChEMBL Target ID: 104643

ChEMBL Target Type: Target is a single protein chain

Result Definitions
TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Activity activity commentActivity activity commentString
2Activity standard flagActivity standard flagInteger
3Activity qualifierActivity qualifierString
4Activity published valueActivity published valueFloat
5Activity standard valueActivity standard valueFloat

Data Table (Concise)
Classification
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