Fig. 6

miR-301a deficiency in the tumor microenvironment inhibits tumor metastasis. Images of representative B16 tumors (a) and LLC1 (b) tumors developed in the lung of mice. WT and miR-301a^−/− mice (n = 8 per group) were implanted with B16 or LLC1 tumor cells by intravenous injection. (c) H&E-stained sections of lungs isolated from WT and KO mice implanted with B16 or LLC1 tumor cells. Scale bars = 200 μm. (d) Runx3 expression in lung tumor sections from WT and KO mice was determined by immunohistochemistry. Scale bars = 100 μm. (e) Western blot analysis of Runx3 expression in lung tumor tissues of WT (n = 4) and miR-301a^−/− (n = 4) mice. (f) CD11c⁺ and CD11b⁺ cells from lung tumors and (g) CD8⁺ and CD4⁺ cells from lung tumors of WT and miR-301a^−/− mice implanted with B16 tumor cells. Tumor-associated CD3⁺ cells (h) and CD11b⁺ cells (i) were purified from B16 tumors harvested from WT (n = 3) and miR-301a^−/− mice (n = 3). miR-301a expression was measured by qPCR. (j) Percentages of infiltrating CD8⁺ and CD4⁺ T cells isolated from B16 tumors from WT (n = 8) and miR-301a^−/− mice (n = 8) as analyzed by flow cytometry (pregated on CD3 events). (k) CD4⁺ and CD8⁺ T cells counts in lung tumor sections from WT (n = 8) and miR-301a^−/− mice (n = 8). (l) Percentages of infiltrating CD11b⁺ and F4/80⁺ cells isolated from B16 tumors developed in WT (n = 8) and miR-301a^−/− mice (n = 8) as analyzed by flow cytometry (pregated on CD3 events). (m) CD11b⁺ and F4/80⁺ T cells counts in lung tumor sections from WT (n = 8) and miR-301a^−/− mice (n = 8). Values represented the mean ± s.d. of three independent experiments. **P < 0.01 or *P < 0.05 indicates a significant difference between the indicated groups (one-way analysis of variance (ANOVA) in h and i and two-tailed, unpaired Student’s t-test in k and m)