Figure 3

Breast cancer CM increase osteoclastogenesis and bone resorption. A. Human OC precursors were primed with M-CSF and RANKL or with M-CSF alone for three days and then cultured for another four days with the addition of CM from MDA-MB-231 cells (CM), IL-8- or PTHrP-stimulated cells (IL-8-CM, PTHrP-CM) or with IL-8 (10 ng/ml) and PTHrP (100 ng/ml) alone. Representative images of TRAP staining are shown and the total number of multinucleated TRAP positive cells per well of a 24-well plate is provided (B). Mean values ± SD of three experiments are reported. C. PBMCs were seeded on Biocoat matrices to evaluate resorption activity. Representative images of resorption pits are shown and the quantification of the total resorption area per well of a 96-well plate is reported as mean values ± SD of three experiments (D). *P < 0.05; **P < 0.02; NS, not significant.