P-glycoprotein and Breast Cancer Resistance Protein Influence Brain Distribution of Dasatinib

Abstract

The novel tyrosine kinase inhibitor dasatinib (Sprycel; BMS-354825) is approved for use in imatinib (Gleevec; STI 571)-resistant or -intolerant chronic myelogenous leukemia and may be useful for other tumors in the central nervous system (CNS). The objective of this study was to investigate the role of Pglycoprotein (P-gp) and breast cancer resistance protein (BCRP) in modulating the CNS penetration of dasatinib. Results from the in vitro studies indicate that cellular delivery of dasatinib is significantly limited by active efflux due to both P-gp and BCRP. Permeability studies indicated greater permeability in the basolateral-to-apical direction than in the apical-to-basolateral direction due to active efflux by P-gp or BCRP. Selective inhibitors of P-gp and BCRP, such as (R)-4-((1aR,6R,10bS)-1,2-difluoro-1,1a,6,10b-tetrahydrodibenzo-(a,e)cyclopropa(c) cycloheptan-6-yl)-␣-((5-quinoloyloxy)methyl)-1-piperazineethanol, trihydrochloride (zosuquidar; LY335979) and 3-(6-isobutyl-9-methoxy-1,4-dioxo-1,2,3,4,6,7,12,12␣-octahydropyrazino1Ј,2Ј: 1,6pryrido3,4-bindol-3-yl)-propionic acid tert-butyl ester (Ko143), were able to restore the intracellular accumulation and abolish the directionality in net flux of dasatinib. In vivo brain distribution studies showed that the CNS distribution of dasatinib is limited, with the brain-to-plasma concentration ratios less than 0.12 in wild-type mice, which increased approximately 8-fold in Mdr1a/ b(Ϫ/Ϫ) Bcrp1(Ϫ/Ϫ) mice. Dasatinib brain distribution was significantly increased in Mdr1a/b(Ϫ/Ϫ) mice and when wild-type mice were pretreated with LY335979. Simultaneous inhibition of P-gp and BCRP by elacridar [N-(4-[2-(1,2,3,4-tetrahydro-6,7-dimethoxy-2-isoquinolinyl)ethyl]-phenyl)-9,10-dihydro-5-methoxy-9-oxo-4-acridine carboxamide] (GF120918) resulted in a 5-fold increase in brain concentration. These in vitro and in vivo studies demonstrate that dasatinib is a substrate for the important efflux transporters p-glycoprotein and BCRP. These transport systems play a significant role in limiting the CNS delivery of dasatinib and may have direct implications in the treatment of primary and metastatic brain tumors.Chronic myelogenous leukemia (CML) accounts for 15 to 20% of all cases of adult leukemia in western populations (Quintá s-Cardama et al., 2007). Imatinib (Gleevec; STI 571) is a first-generation tyrosine kinase inhibitor (TKI) that was approved for use in the treatment of CML and gastrointestinal stromal tumor (Druker, 2003). Imatinib inhibits the BCR-ABL, c-kit, platelet-derived growth factor, and the Ablrelated gene tyrosine kinases . CNS involvement is a common complication seen in CML, and most patients with CML and Ph ϩ acute lymphoblastic leukemia (Ph ϩ ALL) develop extramedullary involvement during the course of their disease. CNS failure has been reported in approximately 20% of imatinib-treated patients with CML or Ph ϩ ALL (Leis et al., 2004). CNS relapses were observed in patients despite a complete hematological response (Leis et Article, publication date, and c...

Cerebrospinal Fluid Can Be Used as a Surrogate to Assess Brain Exposures of Breast Cancer Resistance Protein and P-Glycoprotein Substrates

“…The expression of both Bcrp and Pgp on brain microvessel endothelial cells has been demonstrated, and it has been shown that Bcrp and Pgp work in concert in regulating the penetration of drugs across the BBB (Chen et al, 2009;Polli et al, 2009;Kodaira et al, 2010). For the cosubstrates of both Bcrp and Pgp, however, the function of Bcrp in restricting drug brain penetration is often masked because dmd.aspetjournals.org of the more pronounced role played by Pgp at the BBB.…”

“…For the cosubstrates of both Bcrp and Pgp, however, the function of Bcrp in restricting drug brain penetration is often masked because dmd.aspetjournals.org of the more pronounced role played by Pgp at the BBB. The function of Bcrp can be observed only when the activities of both Bcrp and Pgp are disrupted either by the Pgp/Bcrp dual inhibitor GF120918 or in Mdr1a/1b(Ϫ/Ϫ)/Bcrp(Ϫ/Ϫ) mice (Breedveld et al, 2005;Bihorel et al, 2007;de Vries et al, 2007;Giri et al, 2008;Chen et al, 2009). Therefore, the identification and characterization of a Bcrp-selective substrate becomes necessary when investigating Bcrp function in regulating drug transport across the BBB, as well as evaluating Bcrp-mediated drug-drug interactions.…”

“…It has been shown that Pgp and breast cancer resistance protein (Bcrp) work in concert in restricting drug penetration to the brain (Polli et al, 2009;Kodaira et al, 2010). However, for cosubstrates of both Bcrp and Pgp, the magnitude of Bcrp in restricting drug penetration to the brain is generally not as profound as that of Pgp, likely because of the higher expression of Pgp at the BBB (Breedveld et al, 2005;Bihorel et al, 2007;de Vries et al, 2007;Giri et al, 2008;Chen et al, 2009). The identification and characterization of a Bcrp selective substrate, therefore, become necessary when investigating the function of Bcrp in regulating drug transport to the brain, as well as evaluating Bcrp-mediated drug-drug interactions.…”

In Vitro Characterization of Axitinib Interactions with Human Efflux and Hepatic Uptake Transporters: Implications for Disposition and Drug Interactions

“…2), and they are most are primarily cleared via metabolism by CYP3A4. These chemical features are also typical for substrates of ATP-binding cassette (ABC) transporters (Polli et al, 2008;Chen et al, 2009;Oostendorp et al, 2009;Shukla et al, 2009;Carcaboso et al, 2010).…”

“…These results showed no effect of abcg2 2/2 , a marked increase in brain exposure in abcb1a/b 2/2 , and an even greater increase in the triple knockout. The ability of P-gp and bcrp to work together to limit brain disposition has also been described for lapatinib and dasatinib (Chen et al, 2009;Polli et al, 2009). The results of Poller et al (2011) suggested that the mouse mdr1 limits the brain distribution of axitinib, with the role of bcrp being unclear.…”