clozapine and diphenyl

We recently reported alkoxyl biphenyl derivatives bearing dibenzo[c,e]azepine scaffold as novel P-glycoprotein (P-gp, ABCB1) inhibitors. In this study, their ability to reverse breast cancer resistance protein (BCRP, ABCG2)-mediated multidrug resistance was tested in HEK293/BCRP cells which was BCRP-transfected stable HEK293 cells. It was observed that compounds 4d, 4h, 4i increased mitoxantrone accumulation in HEK293/BCRP cells via inhibiting BCRP efflux function. Notably, the inhibitory activity of 4i was comparable to that of the classical BCRP inhibitor Ko143 at an equimolar concentration. Interestingly, 4i had little inhibitory effect on multidrug resistance-associated protein 1 (MRP1, ABCC1), another drug efflux transporter. These results, together with the previous findings, suggest that 4i may be a dual inhibitor of P-gp and BCRP to warrant further investigation.

Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Biphenyl Compounds; Breast Neoplasms; Cell Line, Tumor; Clozapine; Dose-Response Relationship, Drug; Drug Discovery; Drug Resistance, Neoplasm; Female; HEK293 Cells; Humans; Molecular Structure; Neoplasm Proteins; RNA, Messenger; Structure-Activity Relationship