Fig. 3.

NFV is a substrate and inhibitor of MRP4. (A) Bis(POM)-PMEA uptake was determined in Saos2 or HEK293 cells containing either empty vector or an MRP4 expression vector in the presence of various NFV concentrations. (B) NFV strongly increased Bis(POM)-PMEA cytotoxicity in MRP4-expressing cells (left). NFV uptake was strongly reduced in MRP4-expressing cells (middle). MRP4 expression reduced NFV cytotoxicity (right). (C) The presence of 50 μM NFV (right) increased MTX cytotoxicity in MRP4-expressing Saos2 cells compared with MTX alone (left).