Preserving Bones

摘要

The most common site of metastatic disease in women with advanced breast cancer is bone. These lesions are painful and can be debilitat- ing. Damage occurs when metastatic tumor cells recruit pre-osteoclast cells to the bone and then induce their differentiation into mature bone-degrading cells, which results in the release of proteins from the bone matrix that promote tumor cell growth. In a study exploring the molecules controlling osteoclast differentiation in the cancer setting, Ell et al. have identified miRNAs (microRNAs are small noncoding RNAs that regulate gene expression) whose levels were consistently down- or up-regulated in differentiating osteoclasts. Treatment in a mouse model of metastatic breast cancer with two of the down-regulated miRNAs (miR-141 and miR-219) suppressed bone metastases, suggesting that these miRNAs may have therapeutic utility.