Fig. 2.

The OVCAR8 and NCI/ADR-RES cell line pair confirm P-gp substrates. (A) Trypsinized OVCAR8 or NCI/ADR-RES cells were incubated with 2% bovine serum albumin/PBS containing phycoerythrin-labeled UIC-2 antibody to isotype control antibody for 20 min after which cells were washed in PBS and read on a flow cytometer. Control cells (no antibody) are denoted by red curves, isotype control staining is denoted by blue curves, and P-gp staining is denoted by orange curves (ABCG2 top row, P-gp bottom row). Results from one of three independent experiments are shown. (B) Three-day cytotoxicity assays were performed on OVCAR8 and NCI/ADR-RES cells with imidazole ketone erastin, piperazine erastin, FIN56 or erastin. Where noted, the P-gp inhibitor valspodar was added at a concentration of 10 μM. Results from one of three independent experiments are shown and results are summarized in Table S1.