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Skin cells cloned into embryonic cells

Stem cell breakthrough A breakthrough in stem cell research has been achieved with scientists using cloning techniques to turn human skin cells into embryonic stem cells.

While scientists have previously been able to make embryonic stem cells using this approach in monkeys and mice, until now they have not been able to this with human cells.

Embryonic stem cells can turn into any other cell type in the body, raising the hope this new method could be used for developing personalised therapies, such as creating replacement organs.

While the study was lauded by Australian experts in the field, the ethics and cost of the process did raise concerns.

The work, published today in Cell, uses somatic cell nuclear transfer (SCNT) - the process used to clone Dolly the Sheep.

This process involves placing the genetic material from a body cell, such as a skin cell, and transferring it into an unfertilised donor egg that has had its genetic material removed.

The approach is unlikely be able to create human clones, says lead author Dr Shoukhrat Mitalipov of the Oregon National Primate Research Centre.

Important step

But he says it is an important step in research because it does not require the use of embryos in creating the type of stem cell capable of transforming into any other type of cell in the body.

"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," says Mitalipov.

He says since the reprogrammed cells use genetic material from the patient, there is no concern about transplant rejection.

"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," Mitalipov says.

Dr Bryce Vissel, of the Garvan Institute of Medical Research, says the work is a "breakthrough development".

"This study is an important advance that will not only influence scientific thought but in fact could change future therapies," Vissel says.

"The point is we have a new way to ensure new cells being generated for treatment would be genetically identical to the person being treated, since they originated from that person in the first place.

"We may now be able to take a person's skin cells, use them to make embryonic stem cells, repair genetic problems, and then turn the embryonic stem cells into new nerve cells, for example, that repair the person's brain."

Ethical issues

While the new approach overcomes the immune rejection hurdle, Associate Professor Ernst Wolvetang of the Stem Cell Engineering Group at the Australian Institute for Bioengineering and Nanotechnology says the method still relies on the "willingness of women to undergo super-ovulation and donate [eggs] for such purposes, a procedure that carries both inherent risks and its own socio-ethical concerns".

Associate Professor Andrew Laslett at CSIRO Materials Science & Engineering says the Oregon group has achieved a breakthrough that many worldwide had been seeking.

However, like Wolvetang, he raises concerns over the use of donor human eggs, which he adds "raises a number of ethical issues that should be carefully examined".

Importantly he says more research needs to be done to determine the long-term stability and safety of these SCNT embryonic stem cell lines.

Professor Ed Stanley at Murdoch Childrens Research Institute was less enamoured by the study.

"The paper is of academic interest but unlikely to have any bearing on the therapeutic use of stem cells," he says.

Stanley adds the ability to reprogram tissue-derived cells into embryonic stem cells is already being achieved using "other methods that are much more accessible and simpler".

Human clones concern

While some reports hailed the work as a first step in cloning humans, the researchers were quick to dampen such suggestions, saying their focus was on "therapeutic' uses.

The team pointed out years of research on monkey cells using the same technique have not successfully produced any monkey clones.

Since the human cells used in the study appeared even more fragile, they say it is unlikely clones can be made.

"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," the researchers say.

Scientists hope that stem cell research will offer new pathways in the fight against Parkinson's disease, multiple sclerosis, spinal cord injuries and blindness.