Fig. 6

Effect of exosome secretion inhibitor GW4869 on the progression of osteosarcoma pulmonary metastasis. a Nanoparticle tracking analysis showing inhibition of 143B exosome secretion by utilizating GW4869; b The flowchart showing the plan to test GW4869 on pulmonary metastasis nodules and metastatic lesion area in vivo; c Gross specimens of lungs in three groups; d Weight change of mice in three groups; e Haematoxylin and eosin staining to show the metastatic lesions in the lung of three groups; f–h Maximum diameter, number and areas of metastatic lesion nodules in three groups; i–k Upregulation of E-cadherin and downregulation of N-cadherin were observed in the metastatic lesion treated by GW4869; l, m Suppression of PD-L1 expression at the pulmonary metastatic lesions by administration of GW4869 and upregulation by the treatment of exosomes from 143B cells. Experiments were performed using 5 mice for each group. Data represent mean ± SD