Fig. 2

EndoMT-derived cells promote tumor formation with high macrophage infiltration. a, b Enhancing effect of EndoMT-derived cells on the tumor growth of Panc 02 cell grafts. C57BL/6 mice were subcutaneously injected with Panc 02 cells alone or together with endothelial cells (designated as “Endo”) or EndoMT-derived cells (designated as “EndoMT”) (n = 6 per group). The sizes of developing tumors were superficially measured using a Vernier caliper since day 3 post-inoculation with the formula of ½ × length × width² (a). ^@P < 0.001 when “Panc 02 + EndoMT” group was compared with “Panc 02” or “Panc 02 + Endo” group. Mice were sacrificed on day 30 post-inoculation and tumors were removed (b). ^#P < 0.01 when “Panc 02 + EndoMT” group was compared with “Panc 02” or “Panc 02 + Endo” group. (c) The tumor masses in “Panc 02 + EndoMT” group comprised not only CK18-expressing Panc 02 cells and infiltrating α-SMA⁺ stromal cells, but also α-SMA⁺ and CD31⁺ EndoMT-derived cells (indicated by white arrows). d–f IHC of macrophages from the tumors formed by Panc 02 cells alone or Panc 02 cells plus endothelial cells or EndoMT-derived cells. Tissue sections were stained with F4/80 (d), CD163 (e), or CD204 (f) antibody to detect pan-macrophages (F4/80⁺ cells) or M2-type macrophages (CD163⁺ or CD204⁺ cells). ^#P < 0.01 when “Panc 02 + EndoMT” group was compared with “Panc 02” or “Panc 02 + Endo” group. g, h IHF of the combination of F4/80, iNOS, and Arg1 (g) or the combination of F4/80, MHC II, and CD163 (h), confirming the infiltration of M2-type (F4/80⁺Arg1⁺ or F4/80⁺CD163⁺) macrophages into the tumors derived from Panc 02 plus EndoMT cells