Fumitremorgin C is a specific inhibitor of breast cancer resistance protein (BCRP/ABCG2) multidrug efflux transporter. At 5 μM, it significantly potentiates the toxicity of the chemotherapeutic drugs mitoxantrone, doxorubicin, and topotecan in S1-M1-3.2 colon carcinoma cells. Fumitremorgin C reverses multidrug resistance in cells overexpressing BCRP but not P-glycoprotein (ABCB1) or MRP1 (ABCC1).
