RBV uptake and its inhibition in different cell lines.

<p>(<b>A</b>) Cell monolayers on 24-well plates (done in triplicates) were pretreated for 15 minutes with 15 or 100 µM NBMPR/DMSO or mock-treated with the same amount of DMSO as contained in the treated wells. Cells were then treated with SFM containing 50 µM RBV 1% of which was [³H]RBV for 15 minutes at 37°C. Nucleotide pools were isolated and measured for [³H] as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0011265#s2" target="_blank">Materials and Methods</a>. Uptake values represent CPM divided by number of cells in a 24-well plate and normalized to the uptake by DMSO-treated BHK21 cells (defined as 100%). The mean ± standard deviation is shown for four independent experiments (done in triplicates). (B) Cells monolayers (done in triplicates) on 12-well plates were treated with SFM containing 50 µM RBV 1% of which was [³H]RBV (without uptake inhibitors) at 37°C for 1 h, 16 h or 24 h. Nucleotide pools were isolated and measured for [³H] as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0011265#s2" target="_blank">Materials and Methods</a>. Uptake values represent CPM divided by number of cells in a 12-well plate and normalized to the uptake by BHK21 cells for 1 h (defined as 100%). The mean ± standard deviation is shown for two independent experiments (done in triplicates). (A–B) Statistical analysis was done using one-way ANOVA with Tukey's post hoc test (GraphPad Prism 4, San Diego, CA). ***P<0.001, **P<0.01, *P<0.05, as compared to RBV only treated cells (A) or cells treated with RBV for 1 h (B).