Breast Cancer Resistance Protein Inhibitors

Breast cancer resistance protein (BCRP/ABCG2) is an ATP-driven efflux pump of broad substrate specificity that actively extrudes drugs, dietary toxins and endogenous compounds - including protoporphyrin IX, heme and urate - out of cells. It works at the apical membrane of polarised cells such as hepatocytes and intestinal epithelial cells, where it contributes to the efflux of conjugated substrates from intestine and liver into the gut lumen, and it confers resistance to drugs including mitoxantrone, methotrexate, camptothecin and the anthracyclines through the control of their efflux. Drugs in this class inhibit that transport: UniProt records fumitremorgin C and Ko143 as specific inhibitors, and FDA's table of in vitro transporter inhibitors lists elacridar, fumitremorgin C, ko143 and novobiocin for BCRP.