Fig. 2

SB-699551 affects tumorsphere formation by an irreversible mechanism and targets BTIC. a Schematic of a secondary sphere forming assay and an ex vivo assay of BTIC activity. b The number of tumorspheres that formed in the primary sphere forming assay after exposure to the vehicle or the IC₅₀ and IC₉₀ concentration of SB-699551, and the number of tumorspheres that arose in the secondary sphere forming assay in SB-699551-free media. c Kaplan-Meier survival analysis of mice that were injected with an equal number of viable HCC1954 tumor cells exposed to the vehicle or to various concentrations of SB-699551. Statistical significance was determined by Kaplan-Meier survival analysis and the log-rank test. d Growth curves of the xenografts after transplantation of an equal number of viable tumor cells exposed to the vehicle or to the various concentrations of SB-699551. Each point represents the mean volume of xenografts that arose after transplantation +/− the SEM. e Xenograft mass at endpoint in grams (g). Statistical significance was determined using one-way ANOVA and post-hoc Tukey’s tests. [**** p < 0.0001; *** p = 0.0002; ** p = 0.0025]. The three xenografts arising from mice engrafted with 0.6 μM-treated tumor cells were tiny nodules and were thus excluded from volume and weight analyses