In vivo antitumor efficacy of 17-AAG loaded PMMA in a human multiple myeloma xenograft mouse model

Multiple myeloma (MM) is a monoclonal malignancy characterized by abnormal proliferation of plasma cells. The disease clinically manifests as anemia, hypercalcemia, renal insufficiencies, and osteolytic damage. Osteolytic damage goes with severe bone pain, spinal instability, and pathological fracture, symptoms that are collectively referred to as multiple myeloma bone disease (MMBD). Polymethylmethacrylate (PMMA) bone cement is widely used for bone repair after MMBD surgery, owing to its excellent biomechanical properties and fast curing. To date, however, efficacy of drug-loading PMMA in inhibition of tumor growth and angiogenesis remains unknown. Here, we report that 17-AAG-loaded PMMA bone cement inhibits MM growth in vivo and suppresses tumor diffusion to peripheral tissues. In addition, 17-AAG-loaded PMMA promotes MM apoptosis by downregulating Bax and active Caspase-3.