Figure 4. HOXD genes enhance the amount of TRAP⁺ osteoclasts in the tumor.

Analysis of bone invasiveness and osteolysis of constitutive A673 HOXD10, HOXD11 and HOXD13 shRNA infectants and negative controls in an orthotopic bone xeno-transplantation model (5–11 mice/group). Affected bones were assessed by X-ray radiography and histology. (A) Representative pictures of X-ray radiography and H&E staining showing no clear differences in bone invasiveness between A673 cells with constitutive HOXD10, HOXD11 or HOXD13 knock down and respective controls (X-ray, H&E, scale bar 0.25 mm). (B) Percentage of mice exhibiting infiltration of cortical bone or bone marrow infiltration after intra-tibial injection. (C) TRAP staining of osteoclasts for better visualization and to quantify osteolysis in bone and tumor tissues (scale bar 0.15 mm). (D) Average number of TRAP⁺ osteoclasts attached to the bone or in the tumor (1 mm²) was determined in at least three tumor samples/group (In each sample not less than 20 segments were analyzed).