Mesenchymal Stromal Cells: from Bone Marrow to Neoplastic Disorders

Mesenchymal stromal cells (MSCs) represent a small and heterogeneous subpopulation of mesenchymal stem cells that possesses multilineage differentiation potential. These cells are mainly present in bone marrow, but also in other tissues, and represent a valuable resource for their ability to differentiate into different cell lines and for many therapeutic approaches. MSCs are able to differentiate into cells of mesodermal origin such as adipocytes, chondrocytes, osteoblasts or fibroblasts and in vitro also into cells of non-mesodermal lineages. In bone marrow, they establish the microenvironment for the growth and differentiation of the hematopoietic stem cells (HSCs) resulting crucial for HSC maintenance and haematopoiesis. Nevertheless, the proliferation and/or the survival rate of MSCs may contribute to the onset of different types of bone sarcomas, such as Osteosarcoma, Chondrosarcoma and Giant Cell Tumor of Bone that represent the result of neoplastic degeneration of their corresponding committed mesenchymal precursors, probably as a consequence of the alteration of different or common biochemical pathways.