Fig. 6: c-Myc contributes to RUNX2-mediated BC growth, dissemination, and widespread metastasis.

A total of 1 × 10⁵ 4T1-Luc-GFP cells with c-Myc overexpression, RUNX2 knockdown, c-Myc overexpression combing with RUNX2 knockdown, or corresponding control were orthotopically inoculated into BALB/c mice (n = 10 per group). A The number of GFP-positive cancer cells in peripheral blood, bone marrow, and lungs of the mice (n = 5 per group) were counted at day 14 and day 21 using flow cytometric analysis. B Tumor growth was monitored and quantified. All mice were sacrificed on day 31, and the tumors dissected from the mice are shown. C Representative in vivo and in vitro organ BLI (1 = bone, 2 = lung, 3 = liver, 4 and 5 = spleen, diaphragm, spleen and kidney, and 6 = brain) as well as H&E staining images of the bones and lungs from the indicated mice are shown. The number of mice with metastasis, BoM, and LuM nodes were counted in each group. D RUNX2, c-Myc, PCNA, and SLC1A5 expression in the primary tumors harvested from the indicated mice were detected and quantified by IHC. Representative IHC images of each group are shown. Data are shown as mean ± SD. Statistical analyses were performed with the unpaired Student’s t-test (A, C, and D) or two-way ANOVA (B). *P < 0.05 compared with control cells. ^#P < 0.05 shRUNX2 plus c-Myc compared with shRUNX2 cells. BLI bioluminescence imaging, Met metastasis, BoM bone metastasis.