TGF-β Inhibition Restores Terminal Osteoblast Differentiation to Suppress Myeloma Growth

Multiple myeloma (MM) expands almost exclusively in the bone marrow and generates devastating bone lesions, in which bone formation is impaired and osteoclastic bone resorption is enhanced. TGF-β, a potent inhibitor of terminal osteoblast (OB) differentiation, is abundantly deposited in the bone matrix, and released and activated by the enhanced bone resorption in MM. The present study was therefore undertaken to clarify the role of TGF-β and its inhibition in bone formation and tumor growth in MM.