Figure 4. Resistin promotes VEGF-A expression in osteosarcoma and contributes to angiogenesis through the NF-κB signaling pathway. (A) Osteosarcoma 143B cells were incubated with resistin (10 ng/ml) for the indicated times and p65 phosphorylation was determined by Western blot analysis. (B) Osteosarcoma 143B cells were pretreated with NF-κB inhibitors (PDTC 10 μM; TPCK 3 μM) for 30 min then stimulated with resistin (10 ng/ml) for 24 h. VEGF-A expression was examined by qPCR. (C–D) Osteosarcoma 143B cells were pretreated with NF-κB inhibitors (PDTC 10 μM; TPCK 3 μM) for 30 min then stimulated with resistin (10 ng/ml) for 24 h. CM was collected and applied to EPCs for 24 h. Cell migration and capillary-like structure formation in EPCs were examined by Transwell and tube formation assays, respectively. (E) Cells were transfected with indicated siRNA, the luciferase activity was examined. The results were obtained from three independent experiments. * p < 0.05; ** p < 0.01; *** p < 0.001 compared with controls. # p < 0.05; ## p < 0.01 compared with resistin-treated control groups.