Figure 1.

MDSCs enhance the stemness of colon cancer cells by exosomes secretion. A) Representative western blot analysis of Rab27a expression in total MDSCs and Rab27a siRNA‐treated total MDSCs (representative of three independent experiments). NControl: negative control. B) Measurement of total protein in exosomes secreted by total MDSCs. C,D) Effects of MDSC subpopulations on cancer sphere formation. Primary CT‐26 cells and MDSC subpopulations were cocultured under sphere‐forming conditions for 14 days. A sphere formation assay was performed. Representative photographs were taken (C), and the number of spheres (D) with a diameter >75 µm was counted under a light microscope. E–G) Representative percentages of CD44⁺ or CD133⁺ cells after the coculture of MDSC subpopulations and CT‐26 cells were detected by FCM (E,G), and the results were analyzed statistically (F). H,I) The effect of G‐MDSCs on the development of a CT‐26 tumor model. Tumor‐bearing mice were treated with 1 × 10⁶ G‐MDSCs or Rab27a siRNA‐transfected G‐MDSCs. The tumor incidence was observed every three days (H). A representative tumor from each group is shown on day 21 (I). In B,D,FG) data are shown from three independent experiments. *p < 0.05 and **p < 0.01, analyzed by ANOVA.