Role of RANK-RANKL pathway. (A) Tumor cells were cocultured with immature DCs at a tumor/DC ratio of 1:100 in methylcellulose cultures with or without OPG (0.5 μg/mL). Cultures of DCs alone with or without OPG were used as controls. Cells were harvested for cytospins onto poly-l-lysine–coated slides after an incubation of 2 weeks. Cells were stained for CD11c, CD138, and DAPI as described previously for enumeration of MGCs. *P < .05. (B) Von Kossa staining of monocyte-derived OCLs cultured in the presence of RANKL and M-CSF with or without TSP-1 antibody over BioCoat osteologic discs. Appearance of resorbed bone (pits) is shown. Original magnification, ×10. (C) Quantitative analysis of resorbed bone area mediated by monocyte-derived OCLs cultured with or without anti–TSP-1 mab on osteologic discs. *P < .05.