Mesenchymal stem cells: will they have a role in the clinic?

In addition to hematopoietic stem cells (HSC), human post natal bone marrow contains another stem cell capable of giving rise to multiple mesenchymal cell lineages. Termed mesenchymal stem cells (MSCs) based on their capacity for multi-lineage differentiation, these cells can easily be obtained following a simple bone marrow aspiration procedure and subsequently expanded in culture through as many as 50 population doublings. This extensive capacity for expansion in vitro at clinical scale has recently facilitated the development of clinical trials designed to assess the safety, feasibility, and efficacy of transplanting MSC for a variety of pathological conditions. This review focuses on the background and rationale for performing clinical studies of MSC transplantation and will discuss the potential role that MSC may play in the correction or modification of human diseases.