Fig. 2.

Characterization of exosomes derived from colorectal cancer-associated fibroblasts isolated from colorectal tumor tissues. A. QRT-PCR analysis of the expression of CAF markers (α-SMA and FAP) and fibroblasts marker (Vimentin) in isolated fibroblasts. Remarkably, CAFs displayed low levels of Vimentin, a marker for NF population. B. Immunocytochemical staining of CAF-related proteins α-SMA and PDGFR-α in primary CAFs isolated from CRC patients' tissues. The scale bar represents 100 μM. C. A scanning electron micrograph of purified exosomes reveals spherical and membrane-encapsulated particles with diameters ranging from 50 to 150 nm. D. Western blot analysis revealed that exosomes derived from CAFs were positive for CD9 but negative for calnexin, confirming the successful purification of fibroblast-derived exosomes. The original bots of Fig. 2D are provided in Supplementary Fig. S5. E. Internalization of purified exosomes into endothelial cells. HUVECs were incubated with CAF-derived exosomes labeled with PKH26 (red) for 12 h. A red fluorescence in the cytoplasm of HUVECs indicates significant uptake of exosomes by the cells. Additionally, HUVECs were exposed to PKH26 alone without exosomes as a negative control to monitor any PKH26 carryover. The columns represent the means of three independent experiments, with the bars indicating the standard deviation (SD). ** p-value <0.01. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)