Scientists have successfully reprogrammed human skin cells to become embryonic stem cells capable of transforming into any other cell type in the body.
While researchers have previously been able to make embryonic stem cells in monkeys and mice, this is the first it has been done with human cells.
The results are published today in the journal Cell.
The research team, from the Oregon Health & Science University and the Oregon National Primate Research Center, used a process called somatic cell nuclear transfer (SCNT), otherwise known as therapeutic cloning.
This involves transplanting the nucleus of one cell, containing an individual’s DNA, into an egg cell that has had its genetic material removed.
The unfertilised egg cell then develops and eventually produces stem cells, which could one day be used to replace cells damaged by injury or illnesses such as Parkinson’s disease, multiple sclerosis and heart disease.
“A thorough examination of the stem cells derived through this technique demonstrated their ability to convert just like normal embryonic stem cells, into several different cell types, including nerve cells, liver cells and heart cells,” said lead researcher Dr Shoukhrat Mitalipov.
“While there is much work to be done in developing safe and effective stem cell treatments, we believe this is a significant step forward in developing the cells that could be used in regenerative medicine,” he said.
The research does not involve the use of fertilised embryos, which has been the topic of significant ethical debate since Dolly the sheep was cloned in 1996.
“Our research is directed toward generating stem cells for use in future treatments to combat disease,” Dr Mitalipov said.
“While nuclear transfer breakthroughs often lead to a public discussion about the ethics of human cloning, this is not our focus, nor do we believe our findings might be used by others to advance the possibility of human reproductive cloning.”
Associate Professor Andrew Laslett, Research Group Leader, Stem Cells at CSIRO Materials Science & Engineering, said the findings were “big news” for the stem cell research community and the general public.
“Many groups worldwide, including some in Australia, have been attempting this for a long time,” Professor Laslett said, adding that the breakthrough provides an alternative to induced pluripotent stem (iPS) cells, which can lead to unwanted gene mutations.
“Previous non-human studies have shown that SCNT embryonic stem cells are closer to ‘normal’ embryonic stem cells than are iPS cells,” he said.
“Hence, SCNT embryonic stem cells may be a better option than iPS cells for some applications.”
Professor Bernie Tuch, Director of the NSW Stem Cell Network, said the only downside was the technique required availability of good quality human eggs, because “paid egg donation for this purpose is currently not allowed in Australia”.
Professor Tuch is a member of the Research Consortium at Fertility East, which is attempting to produce stem cells from human eggs that are donated without payments. The program is approved by the NHMRC Embryo Licensing Committee.
But Professor Ed Stanley from the Murdoch Childrens Research Institute’s Stem Cell Technology Laboratory disagreed that the paper would have any bearing on the therapeutic use of stem cells.
“Essentially, the paper shows that human eggs can be used to reprogram tissue-derived cells (for example, skin cells or blood cells) so they become like embryonic stem cells. However, people can already do this using other methods that are much more accessible and simpler,” Professor Stanley said.
With help from the Australian Science Media Centre.