Figure 3From: Tumor-specific expression of αvβ3 integrin promotes spontaneous metastasis of breast cancer to boneTumor αvβ3 integrin enhances osteoclast recruitment and osteolysis following intratibial injection of tumor cells. (a) The relative tumor burden was measured by real-time quantitative PCR 14 days following direct intratibial injection of 66cl4pBabe and 66cl4beta3 cells. Representative H&E-stained sections through tibias injected with (b) 66cl4beta3 or (c) 66cl4pBabe cells. Osteoclasts are marked with arrows. B, bone; T, tumor. Scale bar = 50 μm. (d) Serial sections adjacent to those stained by H&E were stained for tartrate-resistant acid phosphatase (TRAP) activity, and the active osteoclasts (TRAP-positive) present per millimeter of bone in tibias injected with either 66cl4beta3 or 66cl4pBabe cells were counted. Results of two independent experiments are shown. n = 4 mice/group per experiment *P < 0.001.Back to article page