Bone

Breast and prostate cancer cells home to the bone marrow, where they presumably hijack the hematopoietic stem cell niche. We characterize here the elusive premetastatic niche by examining the role of mesenchymal stromal cells (MSC) in cancer cell homing. Decreasing the number of MSC pharmacologically enhanced cancer cell homing to the bone marrow in mice. In contrast, increasing the number of these MSCs by various interventions including G-CSF administration diminished cancer cell homing. The MSC subpopulation that correlated best with cancer cells expressed stem, endothelial, and pericytic cell markers, suggesting these cells represent an undifferentiated component of the niche with vascular commitment. In humans, a MSC subpopulation carrying markers for endothelial and pericytic cells was lower in the presence of cytokeratin+ cells in bone marrow. Taken together, our data show that a subpopulation of MSC with both endothelial and pericytic cell surface markers suppresses the homing of cancer cells to the bone marrow. Similar to the presence of cytokeratin+ cells in the bone marrow, this MSC subpopulation could prove useful in determining the risk of metastatic disease, and its manipulation might offer a new possibility for diminishing bone metastasis formation. Significance: These findings establish an inverse relationship between a subpopulation of mesenchymal stromal cells and cancer cells in the bone marrow. Cancer Res; 78(1); 129–42. ©2017 AACR .

Organic selenium compounds are known to prevent certain cancers although mechanisms may be complex. A widely-held view is that selenium compounds can induce apoptosis in cancer cells, or more precisely, in aberrant cells that are undergoing clonal evolution somewhere along the carcinogenesis process …

Recent laboratory and clinical studies have utilized selenium in the form of pure seleno-L-methionine (SeMet) in combination with DNA-damaging cancer chemotherapy drugs. In mice, the selenium protected bone marrow and other tissues from dose-limiting toxicity. In fact, because of the protection from …