Extended Data Fig. 9. Therapeutic targeting of HOXB13-low tumors with FASN inhibitors in an orthotopic xenograft model.

a. Graph showing tumor volumes after intraprostatic inoculation of PC-3M cells. Tumor formation was confirmed by IVIS one week after inoculation. Then the mice were randomized to receive vehicle (30% PEG400) or TVB-2640 (100mg/Kg) every day for 30 days. Tumor volumes were measured twice per week by IVIS after two weeks of inoculation. Y-axis shows the normalized luciferase intensity. Data in each time point are mean ±s.d. Statistical significance was evaluated by one-way ANOVA (P=0.0007) and comparisons between indicated groups by post hoc Tukey test. PC-3M xenograft tumor growth was not affected by HOXB13 KD (p=0.3212). Importantly, primary tumor growth in both control (pGIPZ, p=0.0171) and HOXB13-KD (shHOXB13, p=0.0082) mice was significantly inhibited by TVB-2640.

b-c. Representative ex vivo IVIS images (b) and quantifications (c) of PC-3M tumor metastasis to the liver and lung (n=6 mice per group). Heatmap shows IVIS signal intensity color scale. Indicated p-values were shown by unpaired two-sided t-test. HOXB13 KD significantly promoted PCa metastases, which was abolished by TVB-2640.

d. Validation of PC-3M tumor metastasis to the liver by H&E and IHC. Luciferase and Pan-keratin IHC were used to identify metastasized PC-3M cells in mouse liver. Representative images of H&E, Luciferase and Pan-keratin staining in indicated group (n=3 mice in each group) are shown. Scale bar: 30 μm. “T” indicates tumor and “n” for normal liver.

e. Kaplan-Meier analyses of overall survival of pGIPZ and HOXB13 KD mice treated with vehicle or TVB-2640 (n=6 mice per group). P values were determined by the log-rank test. TVB-2640 treatment prolonged the overall survival of mice in both control (p= 0.017) and HOXB13-KD (p= 0.005) groups.