[Mechanisms for formation of myeloma bone disease].

Myeloma cells stimulate bone resorption by enhancing osteoclast formation and suppress bone formation by inhibiting osteoblast differentiation. Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta as well as RANK ligand play a major role in the enhancement of bone resorption in myeloma. Myeloma cell-derived soluble Wnt inhibitors as well as TGF-beta released from the bone tissues through enhanced bone resorption are thought to suppress osteoblast differentiation. Such pathognomonically skewed cellular components in the bone marrow create a microenvironment suitable for myeloma cell growth and survival (a myeloma niche) , which should be targeted to suppress myeloma expansion along with amelioration of bone lesions.