Expanding stem cells for successful transplantation
Medical research is looking for more efficient ways to avert complications and serious health issues that can arise with transplantation. The major issues that need to be addressed in this quest are the lack of suitable donors, failed grafting, and graft versus host disease. The EU-funded project 'Stem cell expansion - expansion and engraftment of haematopoietic and mesenchymal stem cells' (Stemexpand) is working to find ways of increasing the number of human hematopoietic stem cells from umbilical cord blood and also of mesenchymal stem cells (MSCs). These can be used for transplantation in cases of blood disorders such as leukaemia. The approach will put in action stem cell regulators that can stimulate self-renewal and an abundance of hematopoietic stem cells. In the case of cord blood samples, this will generate suitable donor samples and drive down mortality due to lack of donors. It will also allow for better short-term and long-term engraftment after transplantation, which will reduce complications and increase successful outcomes. Researchers are also studying how to improve hematopoietic stem cell transplantation by co-transplanting MSCs. The project aims to define the conditions under which they can be expanded. Their use also has potential for reducing the frequency of graft versus host disease. They Stemexpand team has discovered factors which boost stem cell survival. They succeeded in delineating genes and important pathways for stem cell regulation and have singled out 12 short hairpin RNAs (shRNAs). Usually used to silence gene expression, for the purposes of this study they show promise in being able to radically expand hematopoietic cells in culture. Bone marrow MSCs have been characterised and compared among various surgical procedures. The project members are now trying to secure approval in France for a phase I transplantation trial that will use expanded umbilical cord blood stem cells. Two pre-clinical trials have already been performed, and others are underway.