Fig. 7: Fasting further enhances the chemosensitivity of GLUT3 overexpressing GBM to TMZ and CAPE in vivo.

A Scheme of GBM xenograft model establishment and group dosing. 1 × 10⁶ U251-MG cells stably transfected with empty vector or GLUT3 overexpression vector were injected into the left or right axillary fossae of 4-week-old nude mice, respectively. Seven days after tumor injection, when tumor formation is observable, the mice were randomly divided into 6 groups, including control (saline), TMZ-treated (temozolomide 40 mg/kg/dose), CAPE-treated groups (capecitabine 20 mg/kg/dose), and their respective fasting co-treated groups. Intravenous administration was then started every three days, and the combined fasting group was required to undergo a 24 h fast before administration. B The effect of GLUT3 overexpression combined with fasting on tumor growth. C The effect of GLUT3 overexpression combined with fasting on tumor growth under TMZ treatment. D The effect of GLUT3 overexpression combined with fasting on tumor growth under CAPE treatment. The tumor volume is generally calculated by the formula V = (length*width²)/2. IHC staining (E) and score (F) of GLUT3 and Ki67 of the tumor samples from the above groups. G Relative content of temozolomide (left panel) and capecitabine (right panel) in tumor tissues with GLUT3 overexpression and the combination of GLUT3 overexpression and fasting. Data are presented by means ± SEM of (n = 3) F or (n = 6) C or (n = 7) B–D biologically independent experiments. Independent-sample t-tests (B–D second panels), paired t-tests (G), or one-way ANOVA with Tukey’s post-hoc test (B–D third and fourth panels and F) were used for statistical analysis by using SPSS 20 (IBM). A p-value < 0.05 was considered significant (*P < 0.05, **P < 0.01, ***P < 0.001).