Fig. 1.

Human bone marrow mesenchymal stem cell-derived exosomes (HBMSC-Exos) promote tumor proliferation, migration, and invasion in osteosarcoma (OS) cells. (A) Morphology of hBMSC-Exos under transmission electron microscopy (TEM). (B) NTA analysis of hBMSC-Exos revealed that hBMSC-Exos ranges from 50 to 150 nm. (C) Western blot analysis of exosomal proteins including CD63 and CD81 (n = 3). (D) Uptake of the red fluorescence dye Dil-labeled hBMSC-Exos by HOS and MG63 cells. (E and F) Proliferation of HOS and MG63 cells after administering PBS or hBMSC-Exos as measured by CCK-8 assay and EDU staining (n = 3). (G) Representative images of western blot analysis of invasion-related protein levels in HOS and MG63 cells after administering PBS and hBMSC-Exos (n = 3). (H) Effects of hBMSC-Exos on invasion using the transwell invasion assay in HOS and MG63 cells. Quantification of the transwell invasion assay is shown (n = 3). (I) Wound healing assay was performed in HOS and MG63 cells and cell migration was measured 24 h after scratching (n = 3). (J) Representative images of the 3D spheroid BME cell invasion assay in HOS and MG63 cells after administering PBS and hBMSC-Exos (n = 3). *P < 0.05, ^⁎⁎P < 0.01, ^⁎⁎⁎P < 0.001.