The potential of stem cell therapy delivering on its promise of becoming a viable alternative in the clinic is perhaps best evident when looking at Mesoblast, the Australian biotech company that has made headlines many times over the past three years. The company, which develops adult (mesenchymal) stem cell products for the treatment of diseases, including orthopedic, cardiac and vascular, just announced it had received $5.05m from the Australian government for the development of their pipeline of products based on mesenchymal stem cells, buoyed by their recent announcement that trials using their proprietary mesenchymal precursor cells (MPCs) showed promising signs of success in patients with end-stage heart failure.
On the other hand, Mesoblast’s stock price is at an all-time low. This interesting dichotomy is a perfect reflection of the stem cell therapy field, where investments are fluorishing while returns are low on the horizon.
This high-risk, high-reward culture is kept afloat by new discoveries coming from leading research labs at a regular pace.
One such notable discovery, if reactions from the scientific community are to be believed, has the potential to make a significant impact on therapies employing mesenchymal stem cells, if proven to be correct. A research-team led by Juan Melero-Martin, assistant professor at the Cardiac Surgery Research Center at Boston Children’s Hospital, recently published a study in the Proceedings of the National Academy of Sciences which introduces a new paradigm for stem cell therapy: mesenchymal stem cell transplants require endothelial colony-forming cells for optimal engraftment. When the authors implanted mesenchymal stem cells into immunodeficient mice in the presence of cord blood-derived ECFCs, they observed improved engraftment and reduced early apoptosis, more commonly observed with mesenchymal stem cells implanted alone. They discovered that engraftment was regulated via platelet-derived growth factor BB (PDGF-BB)/platelet-derived growth factor receptor (PDGFR)-β signaling.
Based on these results, they finally postulated that co-transplanting MSCs with ECFCs improves transplant efficiency.
For every questions that it answers, however, the study leaves another one unanswered. The potential impact on current therapies – such as, for instance, those that companies like Mesoblast are championing – remains to be seen, as does the regulatory climate surrounding transplantation of what are now two cells into one patient, as opposed to a single one.