Down-regulation of survivin increases sensitivity to BPR0L075 and colchicine in KB and KB- L30 cells. KB and KB-L30 cells were seeded on 96-well plates overnight. Cells were pre-transfected with siR-C (scramble control) or siR-S (survivin specific) for 24 h and incubated with various concentrations of BPR0L075 for 48 h. Cells were analyzed by (A and C) phase-contrast microscopy and (B and D) MTT cell viability assay. Mean differences in cell viability between treatments at same dose of BPR0L075 were labeled on the graph. (E) KB and KB-L30 cells were transfected with siR-C (scramble control) or siR-S (survivin specific) for 24 h and incubated with 10 nM (IC50 value, KB) and 70 nM (IC50 value, KB-L30) of colchicine for 48 hours. Cells were analyzed by MTT cell viability assay. A statistically significant difference in the level of viability between cells treated with siR-S/BPR0L075 combination therapy and BPR0L075 monotherapy is denoted by "*", (p < 0.001).