Mesenchymal stem cells in glioblastoma therapy and progression: How one cell does it all.

Mesenchymal stem cells (MSCs) are among the most investigated and applied somatic stem cells in experimental therapies for the regeneration of damaged tissues. Moreover, as it was recently postulated, MSCs may demonstrate anti-tumor properties. Glioblastoma (GBM) is a grade IV central nervous system tumor with no available effective therapy and an inevitably fatal prognosis. Experimental studies utilizing MSCs in GBM treatment resulted in numerous controversies. Native MSCs were shown to exert anti-GBM activity by controlling angiogenesis, regulating cell cycle, and inducing apoptosis. They also were used as sensitizing factors and vehicles delivering various anti-cancer compounds. On the other hand, some experiments revealed significant risks related to MSC-based therapies for GBM, such as enhancement of tumor cell proliferation, invasion, and aggressiveness. The following review elaborates on all mentioned contradictory data and provides a realistic, current clinical perspective on MSCs' potential in GBM treatment.