Figure 2

Synergistic response to gossypol and TMZ combination therapy in GBM cell lines and primary endothelial cultures. (A–H) GBM and (I, J) endothelial cells were exposed to increasing concentrations of gossypol and/or TMZ for 96 or 72 h, respectively. Cell viability was assessed using the MTT assay. Each treatment condition was replicated in at least three wells and in three independent experiments. Means±s.e.m. of three independent experiments are presented. *P<0.05 compared with control (0 μ M gossypol+0 μ M TMZ), one-way ANOVA and Tukey’s post-hoc test (A, C, E, G, I). The combination indices (CIs) corresponding to the gossypol/TMZ combinations tested in figures (A, C, E, G, I) were determined by the CompuSyn software (B, D, F, H, J, K). A normalised isobolograms (B, D, F, H, J) graphically represent the interaction between gossypol and TMZ, whereas (K) summary table lists all the CI values obtained from the analysis and their interpretations. The combination index (CI) was used to express synergism (CI<1), additive effect (CI=1) or antagonism (CI>1).