Research Paper Volume 15, Issue 22 pp 13010—13040

Figure 10. TOP2A enhances bone-specific metastatic potential and tumor-induced osteolysis in the bone microenvironment. (A) Chemotactic migration of HCCLM3 and Hep3B cells toward MG63 cells was evaluated by transwell assays. (B) The adhesion ability of HCCLM3 and Hep3B cells to MG63 cells was assessed by heterogeneous cell-cell adhesion assay. (C) TRAP staining of bone marrow monocyte (BMM) cells treated with conditioned medium (CM) from HCCLM3 and Hep3B cells. Scale bar, 200 μM. Quantification of TRAP+ osteoclast number. (D) qRT-PCR verified the expression of TRAP, CTSK, and NFACT1 in the indicated groups of BMM cells. GAPDH as the loading control. (E) 2.5×10⁵ control or TOP2A knockdown HCCLM3 and Hep3B cells were injected directly into the tibias of the mice. Representative bioluminescent images taken on day 28 after inoculation are shown. (F) Representative micro-CT images of tibia osteolytic lesions. (G) H&E and TRAP staining of tibia lesions of mice. Quantification of TRAP+ osteoclasts. Scale bar, 100 μm. *P < 0.05, **P < 0.01. B, bone; M, bone marrow; T, tumor. Data presented as mean ± SD. Experiments were repeated at least three times.