Platinum tolerant Pt-R OC cells are at least as sensitive to toxic 6mer seeds as Pt-S cells. A, Change of confluency of A2780 and A2780R cells over time treated with 5 μM cisplatin. B, Dose response curves (96 hrs ATP viability assay) of cells in A. C, Change of confluency of A2780 and A2780R cells over time treated with either 10 nM siNT1, siGGCAGU, or siGGGGGC. D, Viability of the cells in C after transfection with 10 nM of the siRNAs. E, Change of confluency of PEO1 and PEO4 cells over time treated with 1 μg/ml carboplatin. F, Dose response curves (96 hrs ATP viability assay) of cells in E. G, Change of confluency of PEO1 and PEO4 cells over time treated with either 10 nM siGGCAGU or siGGGGGC. H, Viability of the cells in G after transfection with 10 nM of the siRNAs. Each data point (A, B, C, E, F & G) represents mean ± SE of three replicates. Each bar (D, H) represents ± SD of three replicates. P-values were calculated using ANOVA (A, C, E, G), or student’s t-test (D, H). ** p<0.001, * p<0.05.