Another research interest in Hauschka’s lab is the process by which breast cancer cells metastasize –- and this too seems to involve cancer stem cells. “An insidious property of breast cancer is its predisposition to metastasize to bone,” explains Hauschka. “In doing so, breast tumors tend to cause bone destruction as they make room for the breast cancer to expand.” Zhiyuan Zhang, MD, on Hauschka’s team has already shown that injecting human breast cancer cells into mice results in destruction of bone as shown in this mouse knee (at left). By blocking an important stem-cell signaling pathway in the cancer cells before injecting them, they prevented metastasis and bone destruction (as shown in the intact mouse knee at right).