title: Update on the pathogenesis of osteolysis in multiple myeloma patients.
abstract: Multiple myeloma (MM) is a plasma cell malignancy characterized by the high capacity to induce osteolytic bone lesions that mainly result from an increased bone resorption related to the stimulation of osteoclast recruitment and activity. Although it is known that myeloma cells induce osteoclastic bone resorption, the biological mechanisms involved in the pathophysiology of MM-induced bone resorption have been unclear for several years. Recently, new data seem to elucidate which mechanism is critically involved in the activation of osteoclastic cells in MM. The critical osteoclastogenetic factor RANKL and its soluble antagonist osteoprotegerin (OPG) are the major candidates in the pathophysiology of MM bone disease. Human MM cells induce an imbalance in the RANKL/OPG ratio in the bone marrow environment that triggers the osteoclast formation and activation leading to bone destruction. The role or RANKL/OPG system and other osteoclast stimulating factors in the pathophysiology of MM bone disease are summarized in this update.
authors.affiliation: University of Parma, Parma, Italy. Nicola.Giuliani@unipr.it
authors.forename: Nicola
authors.initials: N
authors.lastname: Giuliani
authors.forename: Simona
authors.initials: S
authors.lastname: Colla
authors.forename: Vittorio
authors.initials: V
authors.lastname: Rizzoli
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D001862:Bone Resorption / Q000209:etiology / Q000503:physiopathology; D002352:Carrier Proteins / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor / Q000378:metabolism; D054407:Chemokine CCL4; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016207:Cytokines / Q000502:physiology; D006023:Glycoproteins / Q000502:physiology; D006801:Humans; D015850:Interleukin-6 / Q000502:physiology; D015851:Interleukin-7 / Q000502:physiology; D019402:Macrophage Inflammatory Proteins / Q000502:physiology; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D009101:Multiple Myeloma / Q000150:complications* / Q000503:physiopathology; D009363:Neoplasm Proteins / Q000502:physiology; D010006:Osteoblasts / Q000502:physiology; D010010:Osteoclasts / Q000378:metabolism / Q000473:pathology; D010014:Osteolysis / Q000209:etiology*; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology; D018124:Receptors, Tumor Necrosis Factor; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D054407:Chemokine CCL4; D017077:Culture Media, Conditioned; D016207:Cytokines; D006023:Glycoproteins; D015850:Interleukin-6; D015851:Interleukin-7; D019402:Macrophage Inflammatory Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C505686:TNFRSF11A protein, human; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human; C505687:Tnfrsf11a protein, mouse; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse