fig1
Figure 1. Characterization of A673 cells transfected to express P-gp or ABCG2. (A) Trypsinized A673 EV, B1 or G2 cells were incubated with 2% bovine serum albumin/PBS containing phycoerythrin-labeled antibody to detect ABCG2 (5D3) or P-gp (UIC-2), or the corresponding isotype control antibody for 20 min after which cells were washed in PBS. Control cells (no antibody) are denoted by red curves, isotype control staining is denoted by blue curves, and staining with specific transporter antibodies is denoted by orange curves (ABCG2 top row, P-gp bottom row). Results from one of three independent experiments are shown; (B) Trypsinized A673 EV, B1, and G2 cells were incubated with rhodamine 123 (0.5 µg/mL, for detection of P-gp) or purpurin-18 (15 µM, for detection of ABCG2) with or without appropriate inhibitor (10 µM valspodar for P-gp; 10 µM FTC for ABCG2) for 30 min, after which media was removed and replaced with substrate-free medium continuing with or without inhibitor for an additional 1 h. Cell autofluorescence (control) is denoted by red histograms, substrate efflux is denoted by blue histograms and cells with substrate and inhibitor are denoted by orange histograms. Results from one of three independent experiments are shown; (C) Three-day cytotoxicity assays were performed on
