Figure 2.

Exosomes isolated from SRGN-overexpressing ESCC cells enhance the invasion and metastasis of parental ESCC cells. (A) Western blot analysis of density gradient fractions of crude exosomes from ESCC cells. Crude exosomes isolated by differential centrifugation were purified by density gradient ultracentrifugation and equal volumes of each fraction were applied for Western blot analysis. (B-G) Samples obtained from DUGC F6 were used for further analysis. (B) Equal amounts of proteins from cell lysates and exosomes were loaded for comparison by Western blot. (C) Representative whole-mount TEM images of exosomes derived from ESCC cells. (D) Nanoparticle tracking analysis of exosomes isolated from ESCC cells. (E) Quantitative comparison of exosomes secreted by ESCC cells overexpressing SRGN and empty vector by ZetaView® PMX-220 TWIN Laser. Data are presented as mean ± SD. n = 3 and 4 for KYSE410 and KYSE150, respectively. ns, not significant. (F) Effect of exosomes isolated from Con- and SRGN-overexpressing cells on invasion of parental ESCC cells. Left panel, a schematic diagram of the experiment; middle panel, representative images of the invasion assay; right panel, statistical analysis of the invasion assay. Scale bar, 200 μm. Data are presented as mean ± SD. n = 4 and 3 for KYSE410 and KYSE150, respectively. **, P < 0.01; ***, P < 0.001. (G) Effect of SRGN Exo on the colonization of KYSE150-luc cells to lungs of nude mice. Data are presented as mean ± SD. n = 4. ns, not significant; *, P < 0.05.