The origin and future of hematopoietic stem cells

Abstract

Hematopoietic stem cell (HSCs) therapy in the form of bone marrow transplantations has been used successfully in the clinic for over 40 years and continues to save lives daily. Clinical stem cell transplantations are required to reconstitute the hematopoietic system of cancer patients that have undergone chemotherapy and/or irradiation. Nevertheless, there are still many obstacles with the clinical use of HSCs, including limited availability of transplantable HSCs, donor matching and graft versus host reaction and the difficulty to expand HSCs in vitro. Embryonic stem cells (ESCs) and/or induced pluripotent stem cells (iPSCs) could offer a solution to this problem by providing a means to generate HSCs in vitro. The knowledge to achieve this will likely come from our understanding of the origin of HSCs in the embryo. In this review, I will discuss the ontogeny of HSCs and the prospects of using ESCs and/or iPSCs to generate HSCs.