Research Paper Volume 11, Issue 21 pp 9767—9777

Resistin enhances angiogenesis in osteosarcoma via the MAPK signaling pathway

Figure 3. The MAPK signaling pathway is involved in resistin-promoted VEGF-A expression and contributes to angiogenesis. (A) Osteosarcoma 143B cells were incubated with resistin (10 ng/ml) for the indicated times, and ERK, JNK and p38 phosphorylation was determined by Western blot analysis. (B) Osteosarcoma 143B cells were pretreated with an ERKII inhibitor (10 μM), a JNK inhibitor (SP600125; 10 μM) and a p38 inhibitor (SB203580; 10 μM) for 30 min or transfected with ERK, JNK, and p38 siRNAs for 24 h, followed by resistin (10 ng/ml) stimulation for 24 h. VEGF-A expression was examined by qPCR. (CD) Osteosarcoma 143B cells were pretreated with an ERKII inhibitor (10 μM), a JNK inhibitor (SP600125; 10 μM) and a p38 inhibitor (SB203580; 10 μM) for 30 min, or transfected with ERK, JNK and p38 siRNAs for 24 h, then stimulated with resistin (10 ng/ml) for 24 h. CM was collected and then applied to EPCs for 24 h. Cell migration and capillary-like structure formation in EPCs were examined by Transwell and tube formation assays, respectively. 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.