The great promise of medical treatments involving stem cells has been demonstrated in research where a blood disease has been reversed in a lab mouse.
A team in the US effectively cured a mouse of sickle cell anaemia without using embryos as a stem cell source, so without the ethical concerns associated with embryo experiments.
Scientists at centres in Massachusetts and Alabama reprogrammed ordinary mouse skin cells to become stem cells.
They changed the stem cells into replacement bone marrow cells for transfusion into the mouse, but before doing so they "corrected" the defective gene responsible for the anaemia.
The replacement marrow began producing normal blood cells free of disease.
The achievement is hugely important given it is the first demonstration of what this new type of non-embryonic cell can do in terms of treating disease, the authors note in their report in Science Express, the online version of the journal Science.
"Our results provide proof of principle for using . . . reprogramming combined with gene and cell therapy for disease treatment in mice," they write.
They also point out that this early experiment could not be considered for use yet in humans.
The cell-reprogramming method that allows the creation of embryonic-like stem cells from ordinary adult cells requires the addition of four genes, including virus genes and genes that cause cancer.
These problems "need to be resolved before [ reprogrammed] cells can be considered for human therapy", the authors state.
They add, however, that adult cell reprogramming does dispose of the ethical debate over "therapeutic cloning" and the need to destroy embryos or use stem cell lines originally derived from these embryos.
Ethical problems over the destruction of embryos to harvest their stem cells have dogged this research over the past decade.
Now these ethical concerns have been lifted as no embryos are needed using this reprogramming method.
The work also shows that, as expected, the replacement marrow cells are not rejected by the recipient.
This is because the original cells and the genetic material they contain are donated by the same animal that will receive the reprogrammed cells.
The perfect genetic match means there is no tissue rejection and no need for immuno-suppressive drugs, the authors state.