Fig. 4: rCap markers are upregulated in spontaneous metastasis models and by tumor cell secreted factors.

a–c B16-F10 melanoma cells or PBS (Ctrl) were injected subcutaneously (s.c.) into C57BL/6 mice (a). RT-qPCR for melanoma marker Pmel in blood samples (b) and for Pim3, Inhbb and Bcl3 in isolated lung ECs from Ctrl and tumor bearing mice at 7 and 14 days after tumor implantation (c). n = 5 mice per group. d–h 4T1 mammary carcinoma cells were implanted orthotopically into BALB/c mice and analyzed at indicated time points (d). H&E staining of lung (27 d after tumor initiation) (e) and liver metastasis (6 d and 14 d after tumor intiation) (g) (arrows indicate metastatic nodules). RT-qPCR for Pim3, Inhbb and Bcl3 in isolated lung (n = 4 mice per group) (f) and liver ECs (n = 5 mice per group) (h). i, j Mono- and cocultures of human umbilical vein endothelial cells (HUVEC) with B16-F10 melanoma cells (i). RT-qPCR of PIM3 and INHBB in sorted HUVECs. n = 6 independent experiments for monocultures, n = 7 for B16-F10-HUVEC cocultures (j). HUVECs were treated for 6 h with conditioned medium incubated for 48 h on cancer cell or HUVEC cultures or empty plates, as indicated (k), and analyzed using RT-qPCR. n = 3 independent experiments (l, m). RT-qPCR results are shown relative to Ctrl, normalized to Hprt. One-way Anova with multiple comparisons (b, c, f, h, l, m), two-tailed unpaired t-test (j). Data are presented as mean values ⁺/- SD. Scale bars 50 μm (g, e). Illustrations created in Biorender.com (a, d, i, k). Source data are provided as a Source Data file.