Fig. 1: PDAC-derived exosomes induce TAMs towards M2 polarization and accelerate tumor progression consequently.

A Schematic diagrams of the exosome isolation procedures. Created with BioRender.com. B Representative TEM images of exosomes isolated from KPC (KPC-Exo, left), AsPC-1 (AsPC-1-Exo, middle), and BxPC-3 (BxPC-3-Exo, right) cells. Scale bar, 100 nm. C Analysis of the expression of specific exosomal biomarkers in exosomes isolated from KPC, AsPC-1, and BxPC-3 cells via western blotting. D Size distribution of exosomal particles in exosomes isolated from KPC, AsPC-1, and BxPC-3 cells, as measured by NTA. E Schematic diagrams of evaluating PDAC-derived exosomes’ impacts on PDAC tumor in C57BL/6 mice. Created with BioRender.com. The exosome concentration for injection was diluted based on the NTA results. Each mouse in the exosome group was injected with 100 µL exosome solution per dose, containing 1×10¹⁰ particles of exosomes, with a total of 4 injections. (n = 6). F Tumor volume curves. Black represents intratumoral injection of exosomes (Exo), and red represents intratumoral injection of saline (Saline). (n = 6). G Representative images of subcutaneous tumor tissue. (n = 6). H Tumor weights of subcutaneous tumors. (n = 6). t-test analysis. I Representative Ki-67 staining IHC images (left) and positive cell count statistics (right) of subcutaneous tumor tissue. Scale bar, 100 μm for full images; 50 μm for inset images. (n = 3). t-test analysis. J Representative IF images (left) and positive cell (F4/80⁺CD163⁺) count statistics (right) of subcutaneous tumor tissue. Scale bar, 100μm for full images; 50μm for inset images. (n = 3). t-test analysis. K Analysis of proliferation (left) and M2/M1 macrophage infiltration (right) in tumors. (n = 5). Wilcoxon rank-sum test analysis. Data presented as mean ± SD. n.s. no significant, *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001.