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Multi-Drug-Resistance-Reverting Agents: 2-Aryloxazole and 2-Arylthiazole Derivatives as Potent BCRP or MRP1 Inhibitors

✍ Scribed by Nicola A. Colabufo; Francesco Berardi; Maria Grazia Perrone; Mariangela Cantore; Marialessandra Contino; Carmela Inglese; Mauro Niso; Roberto Perrone


Publisher
John Wiley and Sons
Year
2009
Tongue
English
Weight
311 KB
Volume
4
Category
Article
ISSN
1860-7179

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✦ Synopsis


Abstract

The 2‐aryloxazole and 2‐arylthiazole scaffolds were used for generating compounds that we characterized for their inhibitory activity toward ATP binding cassette transporters involved in multi‐drug resistance, such as BCRP and MRP1, by using tumor cell lines overexpressing each transporter. These SAR studies are a significant step toward improving the inhibitory potency against P‐glycoprotein, BCRP, and MRP1.magnified image

2‐Aryloxazole and 2‐arylthiazole derivatives were evaluated for their inhibitory activity toward P‐glycoprotein (P‐gp) as well as their selectivity toward other ABC transporters involved in multi‐drug resistance such as BCRP and MRP1. These derivatives have 6,7‐dimethoxytetrahydroisoquinoline or cyclohexylpiperazine moieties, which are the same basic nuclei of the potent P‐gp inhibitors MC70 (EC~50~=0.05__μ__M) and PB28 (EC~50~=0.55__μ__M), respectively. The results demonstrate that 2‐aryloxazole and 2‐arylthiazole derivatives, planned as cycloisosteres of MC70, were found to be less potent than the reference compound in inhibiting P‐gp. These compounds were evaluated for their BCRP and MRP1 inhibitory activities. In particular, 6,7‐dimethoxytetrahydroisoquinoline derivatives, unsubstituted, 3‐Br, 3‐Cl, and 3‐OCH~3~ 2‐aryloxalzole derivatives showed the best BCRP inhibitory activity (EC~50~ range: 0.24–0.46__μ__M). In contrast, all cyclohexylpiperazine derivatives except one (EC~50~=0.56__μ__M), showed decreased BCRP inhibitory activity. All compounds tested were unable to inhibit the MRP1 pump, with the exception of the 2‐OCH~3~ and 4‐OCH~3~ derivatives of the 6,7‐dimethoxytetrahydroisoquinoline series, which displayed high MRP1 inhibitory activity (EC~50~=0.84 and 0.90__μ__M, respectively).