Figure 4. AZD1480 inhibited STAT3 activity and growth of NB, RMS and ESFT xenografts in vivo.

Subcutaneous xenografts of NB were established by injection of 2×10⁶ of NB cells (KCNR and SY5Y) into the right flank of 4-6 week-old female nude mice. Orthotopic xenografts of RMS and ESFT were established by injecting 2×10⁷ Rh18 or TC32 cells into the left gastrocnemius muscle of SCID/Beige mice. AZD1480 treatment were initiated when tumors reaches the size at 100-200 mm³. AZD1480 and vehicle were administered daily for up to 3 weeks (30 mg/kg QD for KCNR and SY5Y, 30 mg/kg BID for Rh18 and TC32) by oral garage. Tumor sizes were measured three times a week. A) The graph represents a comparison of mean tumor volumes between control and AZD1480-treated groups in each cell line during the course of AZD1480 or placebo treatment. Data represent mean ± SD. P value between control and AZD1480-treated group in each cell line was determined by a two-way ANOVA. B) Effect of AZD1480 on STAT3 phosphorylation and its downstream targets in tumor xenografts in vivo. Two mice in each group (C=Control group, A=AZD1480-treated group) were killed after 9 doses of AZD1480-treatment in KCNR, SY5Y, Rh18 and TC32, respectively. Tumors were excised and proteins were extracted. Total proteins (15 μg) were analyzed for phosphorylated (p) -STAT3 ^Tyr705, total (T)-STAT3, CyclinD1, CyclinD3, Bcl-2, Survivin and GAPDH by immunoblotting.