Document Detail

UDP-glucuronosyltransferase (UGT) 1A9-overexpressing HeLa cells is an appropriate tool to delineate the kinetic interplay between breast cancer resistance protein (BRCP) and UGT and to rapidly identify the glucuronide substrates of BCRP.
MedLine Citation:
PMID:  22071170     Owner:  NLM     Status:  MEDLINE    
The interplay between phase II enzymes and efflux transporters leads to extensive metabolism and low bioavailability for flavonoids. To investigate the simplest interplay between one UDP-glucuronosyltransferase isoform and one efflux transporter in flavonoid disposition, engineered HeLa cells stably overexpressing UGT1A9 were developed, characterized, and further applied to investigate the metabolism of two model flavonoids (genistein and apigenin) and excretion of their glucuronides. The results indicated that the engineered HeLa cells overexpressing UGT1A9 rapidly excreted the glucuronides of genistein and apigenin. The kinetic characteristics of genistein or apigenin glucuronidation were similar with the use of UGT1A9 overexpressed in HeLa cells or the commercially available UGT1A9. Small interfering (siRNA)-mediated UGT1A9 silencing resulted in a substantial decrease in glucuronide excretion (>75%, p < 0.01). Furthermore, a potent inhibitor of breast cancer resistance protein (BCRP), 3-(6-isobutyl-9-methoxy-1,4-dioxo-1,2,3,4,6,7,12,12a-octahydropyrazino[1',2':1,6]pyrido[3,4-b]indol-3-yl)-propionic acid tert-butyl ester (Ko143), caused, in a dose-dependent manner, a substantial and marked reduction of the clearance (74-94%, p < 0.01), and a substantial increase in the intracellular glucuronide levels (4-8-fold, p < 0.01), resulting in a moderate decrease in glucuronide excretion (19-59%, p < 0.01). In addition, a significant, albeit moderate, reduction in the fraction of genistein metabolized (f(met)) in the presence of Ko143 was observed. In contrast, leukotriene C₄ and siRNA against multidrug resistance protein (MRP) 2 and MRP3 did not affect excretion of flavonoid glucuronides. In conclusion, the engineered HeLa cells overexpressing UGT1A9 is an appropriate model to study the kinetic interplay between UGT1A9 and BCRP in the phase II disposition of flavonoids. This simple cell model should also be very useful to rapidly identify whether a phase II metabolite is the substrate of BCRP.
Wen Jiang; Beibei Xu; Baojian Wu; Rong Yu; Ming Hu
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2011-11-09
Journal Detail:
Title:  Drug metabolism and disposition: the biological fate of chemicals     Volume:  40     ISSN:  1521-009X     ISO Abbreviation:  Drug Metab. Dispos.     Publication Date:  2012 Feb 
Date Detail:
Created Date:  2012-01-19     Completed Date:  2012-05-18     Revised Date:  2013-06-27    
Medline Journal Info:
Nlm Unique ID:  9421550     Medline TA:  Drug Metab Dispos     Country:  United States    
Other Details:
Languages:  eng     Pagination:  336-45     Citation Subset:  IM    
Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77030, USA.
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MeSH Terms
ATP-Binding Cassette Transporters / antagonists & inhibitors,  metabolism*
Apigenin / metabolism,  secretion
Biological Transport / drug effects
Drug Evaluation, Preclinical / methods*
Flavonoids / metabolism*,  secretion
Gene Silencing
Genistein / metabolism
Glucuronides / metabolism*,  secretion
Glucuronosyltransferase / antagonists & inhibitors,  genetics,  metabolism*
HeLa Cells
Leukotriene C4 / pharmacology
Membrane Transport Modulators / pharmacology
Multidrug Resistance-Associated Proteins / antagonists & inhibitors
Neoplasm Proteins / antagonists & inhibitors,  metabolism*
Osmolar Concentration
RNA, Small Interfering
Recombinant Proteins / metabolism
Substrate Specificity
Uridine Diphosphate Glucuronic Acid / metabolism
Grant Support
Reg. No./Substance:
0/ABCG2 protein, human; 0/Flavonoids; 0/Glucuronides; 0/Membrane Transport Modulators; 0/Multidrug Resistance-Associated Proteins; 0/Neoplasm Proteins; 0/RNA, Small Interfering; 0/Recombinant Proteins; 2616-64-0/Uridine Diphosphate Glucuronic Acid; 446-72-0/Genistein; 520-36-5/Apigenin; 72025-60-6/Leukotriene C4; EC; EC 1A9

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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