Figure 3. JNK is required for the maintenance of the tumour-initiating potential of stem-like glioblastoma cells.

(a) TGS01 cells (1×10⁶) pretreated with SP600125 (40 μM) or the control vehicle for 7 days were implanted subcutaneously into the right flank of nude mice (5 mice per group). Tumour volume was measured at the indicated time points and the results presented as mean tumour volume ± s.d. (left). At the end of the observation period, mice were sacrificed and the weight of subcutaneous tumours was measured (right bottom). Representative subcutaneous tumours formed by SP600125- and control-treated stem-like glioblastoma cells are shown (top right). *P < 0.05. (b) TGS01 cells (1×10⁶) transiently transfected with siRNAs against JNK1 or JNK2, or with a control siRNA were implanted subcutaneously into the right flank of nude mice 7 days after transfection (5 mice per group). Mice were then analysed as in (a). *P < 0.05. (c) A Kaplan-Meier plot (right) showing the survival of mice (5 mice per group) after intracranial implantation of TGS01 cells (1×10⁴) pretreated with SP600125 (40 μM) or the control vehicle (DMSO) for 7 days. Representative images of haematoxylin and eosin staining of the brain sections from mice sacrificed at 60 days after implantation are shown (left). *P < 0.05.