Figure 5. PVT1 in BMSC-EXO promotes osteosarcoma growth and metastasis via increasing ERG in vivo. The mouse xenograft (n=18) was established by subcutaneous inoculation of MNNG/HOS cells, and the pulmonary metastatic model (n=18) was established by tail vein injection of MNNG/HOS cells. Eight days after the establishment of xenograft and 3 weeks after the establishment of metastatic model, mice were divided into 3 groups, the control group (with PBS injection in tail vein, n=6), the exosome group (with 10 μg of BMSC-EXO injection in tail vein, n=6), and the exosomes+si-PVT1 group (with PVT1-interfering BMSC derived exosome injection in tail vein, n=6). (A) The tumor volume was detected every 4 days. (B) The expression of PVT1 and ERG in tumor tissues after 3 weeks. (C) The number and the H&E staining of lung metastatic nodules (red arrows). *p<0.05, **p<0.01 vs control. #p<0.05, ##p<0.01 vs exosomes.