IRX1 inﬂuences peritoneal spreading and metastasis J Jiang et al 4501 Figure 3 Effect of enforcing IRX1 on tubular formation in vitro. The supernatants from cells with or without IRX1 transfection were collected. After 18 h co-cultivation with HUVECs, tubular formation was evaluated. (a) Poorly formed tubular structure was observed in SCG-7901/IRX1 group, compared with mock or controls. (b) The bar charts represent the counting of tubules number (left, *Po0.001), tubular length (middle, *P ¼ 0.022) and intersecting nods (right, *Po0.001) between different groups. The data represent the mean±s.d. of three independent experiments. Figure 4 Effect of enforcing IRX1 on vasculogenic mimicry in vitro. Tumor cells of 1.5 105 with or without IRX1 transfection were plated onto the 3D gel plate. After 4-day culture, the cells were stained with PAS reagent. (a) Microscopically, less tubular structures with PAS stain were observed in IRX1 transfectant, compared with mock or controls (the bar indicates 20 mm). (b) IRX1 transfectants revealed strong inhibiting effect on tubular length of vasculogenic mimicry (top, 239.52 mm±6.32 vs 419.77 mm±48.90 or 448.79 mm±22.30, *Po0.001) and tubular intersecting nods (down, 6.6±1.14 vs 16±2.0 or 14.4±1.14, *Po0.001). Each experiment was performed at least three times. interfering RNA (siRNA) in SGC-7901 cancer cells, and observed the efﬁcacy on angiogenesis by endothelial tube formation assay. After 48 h siRNA interference, a signiﬁcant reduction of endothelial tube formation was identiﬁed in BDKRB2-siRNA group (11.75±2.36), compared with mock (17.75±1.25) or controls (19.75±2.22), by calculation of the tubular numbers (P ¼ 0.001; Figure 6b). We introduced siRNA-speciﬁc targeting IRX1 to SGC-7901 cancer cells and found that knockdown of IRX1 in gastric cells reversed the Oncogene