Stem cells likely to be safe for use in regenerative medicine, study confirms
SCI researchers have found the strongest evidence to date that human pluripotent stem cells – cells that can give rise to all tissues of the body – will develop normally once transplanted into an embryo. The findings, published in the journal Cell Stem Cell, could have important implications for regenerative medicine.
Human pluripotent stem cells for use in regenerative medicine or biomedical research come from two sources: embryonic stem cells, derived from fertilised egg cells discarded from IVF procedures; and induced pluripotent stem cells, where skin cells are ‘reset’ to their original, pluripotent form. They are seen as having promising therapeutic uses in regenerative medicine to treat devastating conditions that affect various organs and tissues, particularly those that have poor regenerative capacity, such as the heart, brain and pancreas. However, some scientists have been concerned that the cells may not incorporate properly into the body and hence not proliferate or distribute themselves as intended, resulting in tumours.
This study suggests that this will not be the case and that stem cells, when transplanted appropriately, are likely to be safe for use in regenerative medicine. Professor Roger Pedersen from the Stem Cell Institute at the Anne McLaren Laboratory for Regenerative Medicine, commenting on co-author Victoria Mascetti’s research findings, says: “Our study provides strong evidence to suggest that human stem cells will develop in a normal – and importantly, safe – way. This could be the news that the field of regenerative medicine has been waiting for.” The best way to test how well stem cells would incorporate into the body is to transplant them into an early-stage embryo and see how they develop. As this cannot be done ethically in humans, scientists use mouse embryos. The gold standard test, developed in Cambridge in the 1980s, involves putting the stem cells into a mouse blastocyst, a very early stage embryo after fertilisation, then assessing stem cell contribution to the various tissues of the body. Previous research has not succeeded in getting human pluripotent stem cells to incorporate into embryos. However, in research funded by the British Heart Foundation, Victoria Mascetti and Professor Pedersen have shown that it is possible to successfully transplant human pluripotent stem cells into the mouse embryo and that they then develop and grow normally.
Publication details: Mascetti VL, Pedersen RA. Human-Mouse Chimerism Validates Human Stem Cell Pluripotency. Cell Stem Cell. PMID: 26712580
Full article in Cell Stem Cell