Simvastatin and MBCD Inhibit Breast Cancer-Induced Osteoclast Activity by Targeting Osteoclastogenic Factors.

Previous reports have documented that cholesterol-lowering simvastatin prevented osteolytic metastasis of breast cancer in animal model in which cancer cells were placed into blood circulation. Thus, simvastatin treatment might have a preventive effect in inhibiting osteoclast activity of metastatic bone microenvironment. This study documented that both simvastatin and MBCD (cholesterol depleting drug) blocked the breast cancer-induced TRAP and MMP activity, and expressions of various osteoclastogenic genes (TRAP, Cathepsin K, and NFATc1) in pre-osteoclast RAW264.7 cells, and osteoclastogenic CSF-1 and RANKL expressions in breast cancer MCF-7 cells. Thus, these findings unravel a molecular mechanism of simvastatin-/MBCD-mediated inhibition of breast cancer-driven osteoclast activity.