Figure 1.
CHO-MG cells exhibit MGBG resistance and impaired BODIPY–PUT uptake.A and C, cells were treated for 24 h with the indicated concentrations of MGBG alone (A), or PUT with or without 50-μM MGBG (C). CellTiter 96 AQueous One Solution Cell Proliferation Assay (MTS) was used to assess cell viability and dose–response curves were plotted (n = 3). B, cells were treated with 5-μM BODIPY–polyamines for 90 min at 37 °C with or without 90 min of 1-mM BV pretreatment to inhibit polyamine uptake. Uptake was measured in terms of the mean fluorescence intensity (MFI) up to 1 × 104 events (debris free) per condition on the flow cytometer (n = 3). Data represent the mean ± SEM (A and C) or mean ± SD (B), and individual data points (representing replicates) are overlaid on bar graph plots (€p < 0.05, ∗∗∗∗/€€€€p < 0.0001, ∗∗∗∗versus CHO-WT(+MGBG), €€€€versus CHO-MG(+MGBG)). Analyses were performed using two-way ANOVA and Bonferroni post hoc corrections. BODIPY, boron dipyrromethene; BV, benzyl viologen; MGBG, methylglyoxal bis-(guanyl hydrazone); SPD, spermidine; SPM, spermine; PUT, putrescine.