In:
Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 17, No. 2 ( 2011-01-15), p. 294-301
Abstract:
Purpose: Organic anion-transporting polypeptides (OATP) mediate the cellular uptake of a broad range of drugs. The hydrophobic anticancer drug, paclitaxel (PTX), was recently identified as a substrate for OATP1B3 in vitro. We investigated the role of Oatp1a/1b transporters in the pharmacokinetics of PTX in vivo, as well as their impact at different dose levels of PTX and methotrexate (MTX). Experimental Design: Recently generated Slco1a/1b−/− (lacking all Oatp1a/1b transporters) and wild-type mice were intravenously dosed with 2, 10, or 50 mg/kg of PTX, or with 10, 50, or 500 mg/kg of MTX, and plasma and tissue drug concentrations were measured. Results: In spite of its hydrophobicity, PTX systemic exposure (at 10 mg/kg) was increased by greater than 2-fold in Slco1a/1b−/− mice compared with wild-type, whereas PTX liver uptake was reduced by about 2-fold. Oatp1a/1b transporters displayed a high impact on PTX and MTX pharmacokinetics over a broad dose range. For MTX, even at 500 mg/kg, saturation of Oatp1a/1b was not observed, with a 3.4-fold increase in plasma and 30-fold decrease in liver levels in Slco1a/1b−/− mice compared with wild-type. Although beginning saturation of Oatp1a/1b was observed at the highest dose of PTX, plasma levels in Slco1a/1b−/− mice were still 1.7-fold increased and liver levels 1.5-fold decreased compared with wild-type. Conclusion: Oatp1a/1b transporters play a pronounced role in determining plasma levels and tissue distribution of MTX and PTX, thus affecting even highly hydrophobic drugs. Variation in OATP1A/1B transporter activity, due to genetic variation, inhibition, and/or tumor expression might affect toxicity and therapeutic efficacy of these anticancer drugs. Clin Cancer Res; 17(2); 294–301. ©2010 AACR. Clin Cancer Res; 17(2); 294–301. ©2010 AACR.
Type of Medium:
Online Resource
ISSN:
1078-0432
,
1557-3265
DOI:
10.1158/1078-0432.CCR-10-1980
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2011
detail.hit.zdb_id:
1225457-5
detail.hit.zdb_id:
2036787-9
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