Human embryos may not be needed for stem cell research

A NEW technique that creates human stem cells from fragments of skin could end the controversial use of human embryos to harvest stem cells, according to an Irish expert in human stem cell research.

Harvard-based Stephen Sullivan said the new method could end the ethical dilemma faced by many Irish scientists in a country where there is robust pro-life opposition to use of human embryos in research.

“We can now re-programme stem cells without the need for cloning, thus releasing the constraints faced by scientists in Ireland for the past decade,” Dr

Sullivan said.

The new method, pioneered by Professor Shinya Yamanaka of Kyoto University, Japan, involves genetically modifying adult cells to make them almost as flexible as stem cells.

Dr Sullivan said Prof Yamanaka’s work shows that with a small number of genes introduced into a human skin cell, the memory of what a cell does is lost, and this causes the cell to revert back to a pluripotent stem cell-like state. A pluripotent cell can form any cell in the body and can be grown in huge numbers in laboratory conditions.

“Previously Irish scientists only had access to adult stem cells and stem cells from amniotic fluid, these cells cannot be grown in numbers in the lab and can only make very limited numbers of cell types.

“In contrast pluripotent stem cells can be expanded in number in a test tube very easily, allowing potentially limitless amounts of material for study,” said Dr Sullivan.

Initially, the method will be used by pharmaceutical companies for drug screening.

However, it will also allow scientists to study cell changes in the earliest stages of a disease, helping to understand what is behind its onset.

“The way it is at the moment, it’s like arriving at the murder scene years after the crime was committed — you study the degenerative disease years after its onset and after its gone through its most progressive stages.

This new technique should change that,” said Dr Sullivan.

However, he warned that the one remaining caveat with this new method is that it uses potentially cancer forming viruses to introduce the novel genes. His work at Harvard involves tackling this problem.

The results of Prof Yamanaka’s research are due for publication today in the scientific journal Cell.

Dr Sullivan, who was born in Cork, earned his PhD in the Roslin Institute (Edinburgh) under Professors Jim McWhir and Ian Wilmut, two of the scientists responsible for cloning Dolly the sheep.

Dr Sullivan is a research fellow at Harvard University. He is chief editor of Human Embryonic Stem Cells — The Practical Handbook, published this year.