The dual role of mesenchymal stem cells in tumor progression

Mesenchymal stem cells (MSCs) have attracted increasing interest in the field of oncology because of their inherent capacity to migrate and home tumor tissues. The remarkable tropism of MSCs for tumor microenvironments has been exploited in order to use these cells as cellular vehicles to deliver gene therapies or anticancer agents. At functional levels, these cells display chemotactic properties similar to those of immune cells in response to tissue insult and inflammation and secrete a broad range of bioactive biomolecules with an impact on tumor development and a progression through direct actions on tumor cells and the stromal microenvironment. However, the exact contribution of such interactions in tumor progression has not yet been fully clarified, and some concerns remain regarding whether MSCs exert a tumor-suppressive effect or, on the contrary, favor tumor growth. The article by Keramidas and colleagues in this issue of Stem Cell Research & Therapy provides an interesting contribution to this hot topic.