Figure 6. CLIO-ICTs increase the anti-tumor efficacy of temozolomide (TMZ) in vivo.
(a) In vitro analysis of TMZ chemosensitivity by cell viability assay. Panel of GBM cells were exposed to increasing doses of TMZ (0-500 μM) for 72hrs and cell viability was calculated by MTS assay. For in vivo experiments, tumors were initiated with orthotopic injections of pcGBM39 cells (b-f) and pcGBM2 cells (g-i). Mice were treated with TMZ alone (200mg/kg) or in combination with CLIO-ICT (0.5 mmol Fe/kg and 80mg/kg of ICT) and ICT (80mg/kg of ICT), CLIO (0.5 mmol Fe/kg) or vehicle. (b) Representative T2 weighted MR images of mice brain. T2 FSE sequences were used to capture coronal T2 weighted images. Yellow dotted line represents tumor periphery. (c) Quantification of tumor volumes before and after treatment. T2 weighted MR scans were used to calculate tumor volumes using Osirix software. Bioluminescent in vivo images of tumors in control and treated mice in pcGBM39 (d) and pcGBM2 (g) tumor models. (e and h) Quantification of the bioluminescent signals. Fold change in total flux represents the ratio: total flux after treatment/total flux before treatment. *P < 0.05, respectively, n = 6 (pcGBM39) and n = 6 (pcGBM2), one-way ANOVA. (f and i) Kaplan–Meyer survival curves of control and treated mice (n=6, pcGBM39; n=6, pcGBM2) demonstrate a significant survival benefit of CLIO-ICT and ICT in combination with TMZ as compared to vehicle, log-rank Mantel–Cox test. *P < 0.05, **P < 0.005, n=6, one-way ANOVA.