Figure 5: IL-33 induces infiltration of M2-like TAMs and metastasis.

(a) IL-33 expression levels in vector- and IL-33-T241 tumour xenografts (n=6 samples per group). (b) FACS analysis of the total F4/80⁺ macrophages in vector- and IL-33-T241 tumour tissues (n=5 samples per group). (c) Heatmap of M1 and M2 related genes by genome-wide expression profiling of F4/80⁺ cells isolated from Panc02 tumour grafts implanted in wt and St2^−/− mice (n=3 samples per group). (d) In vitro matrigel invasion of GFP⁺ LLC tumours in the presence of IL-33 or vehicle-stimulated macrophages (n=6 samples per group). Arrowheads point to spread GFP⁺ tumour cells. Scale bar, 100 μm. (e) FACS analysis and quantification of RFP⁺ circulating tumour cells in the peripheral blood of vector- and IL-33-T241 tumour-bearing mice (n=5 samples per group) at the time point of the average tumour size of 1.5 cm³. (f) Bioluminescent imaging of tumour-bearing mice implanted in livers with luciferase⁺ vector- and IL-33-T241 tumours. Arrowheads point to luciferase⁺ tumours. Quantifications of bioluminescence signals and liver weights (n=5 samples per group). NS, not significant. (g) Bioluminescent imaging of lungs of luciferase⁺ vector- and IL-33-T241 tumour-bearing mice. Arrowheads point to luciferase⁺ metastatic nodules. Quantifications of luciferase⁺ pulmonary metastases (n=8 animals per group; mean±s.e.m., NS, not significant, Student’s t-test).