Proteoglycans: key partners in bone cell biology

The complex proteoglycan (PG) composition in bone is addressed together with the specific role played by PGs in bone biology, as regulatory molecules for bone resorption and their involvement in bone tumor development. The roles of anl PG (HSPG) families as bone pro-resorptive agents and promoters of asteolytic tumor have made them good targets for new therapeutic approaches to these osteolytic bone tumors.