Cells with Unique Properties in Prostate Cancer-Associated Stroma are Mesenchvmal Stem Cells

The importance of tumor stroma in prostate cancer development and progression has been recognized through its stimulating effects on cancer cell growth, migration and angiogenesis. Our hypothesis was that the prostate cancer stroma is derived, at least in part, from mesenchymal stem cells (MSCs) that are proliferative, multipotent and self-renewing. Our objective was to demonstrate that cancer-derived stromal cells have characteristics of mesenchymal stem cells. Comparing primary cultures of stromal cells from cancer versus normal tissues, we observed (a) differential gene expression profiles, (b) increased expression of autotaxin, a motility factor, (c) increased expression of the MSC-associated antigen CD90, and (d) increased expression of transforming growth factor-beta, associated with tumor promotion, in CD90-positive cells. Many of these properties are consistent with a mesenchymal stem cell phenotype of prostate cancer-associated stroma, supporting our hypothesis.