Figure 3. Genetic and pharmacological inhibition of EZH2 inhibits growth in vivo.

(A) Tumor EZH2 and H3K27me3 levels in mice implanted with the human neuroblastoma cell line NGP expressing a doxycycline-inducible shEZH2 after 20 days of doxycycline or control treatment in vivo. Proteins and histones were extracted from tumors in 3 control mice and in 3 doxycycline-treated mice. GAPDH is a control for EZH2, and H3 is a control for H3K27me3. (B) Tumor volume in mice (n = 5 for each group) implanted with NGP cells expressing a doxycycline-inducible shEZH2. Results are representative of 2 independent experiments; mean ± SEM is shown. P calculated using 2-way ANOVA. (C) Kaplan-Meier curves with log-rank (Mantel-Cox) test showing overall survival of mice (n = 5 for control and n = 5 for doxycycline treated) implanted with the neuroblastoma cell line NGP expressing a doxycycline-inducible shEZH2. Results are representative of 2 independent experiments. (D) Tumor volume in mice (n = 10 for each group) treated with JQEZ5 or vehicle in a mouse xenograft model of the neuroblastoma cell line Kelly. Mean ± SEM is shown. P calculated using 2-way ANOVA. (E) H3K27me3 levels in mice with human neuroblastoma cell line CHP-212 xenograft after 10 days of GSK126 or vehicle treatment. Histones were extracted from circulating white blood cells in 4 GSK126-treated mice and 4 vehicle-treated mice. (F–H) Tumor volume over 21-day treatment with vehicle or 150 mg/kg/d GSK126 treatment in a mouse xenograft model of CHP-212 (F, n = 8 each), SK-N-BE(2) (G, n = 7 each), and SH-SY-5Y (H, n = 8 each). Mean ± SEM is shown. P calculated using 2-way ANOVA. (I and J) Kaplan-Meier curves show overall survival of mice with SK-N-BE(2) (I, n = 7 each) or SH-SY-5Y (J, n = 8 each). P calculated using log-rank (Mantel-Cox) test.