Fig. 6

TSPAN18 promotes bone metastasis of PCa cells in vivo. a-b Representative images of bioluminescence (a) and X-ray (b) of bone metastasis through caudal artery injection. The red arrows show bone metastases. c Western blot analysis of TSPAN18 expression in stably TSPAN18-knockdown or TSPAN18-overexpressing cells and control cells. d TSPAN18-knockdown, TSPAN18-overexpressing and corresponding control PC-3 cells stably expressing luciferase were injected into nude mice through caudal artery, then the bone metastasis was weekly measured using an in vivo IVIS system. Representative bioluminescence images at indicated weeks from each group were shown. e Kaplan-Meier curves for metastasis-free survival of mice bearing PC-3 cells as indicated. f The counts of metastasis in indicated groups (n = 6/group). g Representative immunohistochemical images of micro-CT, H&E and luciferase, and immunofuorescent staining of E-cadherin (green) and N-cadherin (red) in each group as indicated. The nucleus is labeled with DAPI (blue). Scale bars: red, 50 μm. h The tumor volume to the bone volume ratio was calculated for each mouse and presented in the plot at right. *p < 0.05, **p < 0.01 student’s t test