Fig. 4

Cytotoxic effect of BI6727 in the presence of cisplatin a Cells were seeded at 1000 cells/well in 50 μl, 20–24 h prior to the addition of the drug in 50 μl. XTT assay was performed 3 days later upon drug treatment. The viability was calculated relative to no drug treatment and the error bars represent standard error calculated from three replicates. b XTT assays were performed as described in Fig. 4a except using two inhibitors of Cisplatin and BI6727 in 50 μl. PEO1 and PEO4 were seeded at 2000 cells per well. c CD133 surface expression and ALDH1 activity were measured by flow cytometry in Ovcar5 and Ovcar8 cells grown in either RPMI or SCM. The data are compiled from 4 (for Ovcar5) and 3 (for Ovcar8) independent experiments. For statistical analysis, the differences in positive population of markers were calculated by 2-tailed t-test d Ovcar5 and Ovcar8 cells (2 × 10³ cells/well) were seeded on white plates in RPMI media containing 10 % FBS or in serum-free stem cell media containing 20 ng/ml EGF and 10 ng/ml FGF. Twenty-four hours after seeding, cells were treated with cisplatin or BI6727. The viability was measured using the CellTiter Glo and calculated relative to no drug treatment and the error bars represent standard error calculated from three experiments. * p < 0.05 by one-way ANOVA with Tukey post-hoc test. T (trend), p ≤ 0.2