NZ scientists seek right to take human embryos

By SIMON COLLINS

New Zealand researchers want the right to destroy human embryos in order to grow stem cells that might one day provide cures for conditions such as Parkinson's disease.

A lineup of scientists at the NZ Bioethics Conference in Dunedin at the weekend called for a relaxation of the ban on taking stem cells from embryos.

Most urged New Zealand to follow Britain and Singapore in allowing scientists to create embryos specifically for the purpose of taking stem cells from them.

If the Government was not prepared to go that far, they suggested a compromise allowing stem cells to be taken from surplus embryos created for in-vitro fertilisation (IVF).

At present, these surplus embryos are destroyed anyway as soon as a couple has had a child.

The stem cell issue is back in the headlines after South Korean researchers succeeded last week in cloning 30 egg cells taken from Korean women and growing the new cells to form embryos without the need of male sperm.

The researchers then took stem cells from one of the embryos and grew them into a variety of cells, including eye cells, muscle cells and bone cells.

Stem cells are cells that can develop into any specific kind of cell in the body.

At a very early stage in embryo development, each human stem cell has the capacity to grow into an entire human being.

But Otago University anatomy professor Gareth Jones told the conference that actually even the earliest stem cells in a newly fertilised embryo could only grow into an entire person in the right chemical environment inside a woman's womb.

Taking stem cells from an embryo in a laboratory dish in order to grow new brain cells for a patient with Parkinsons, for example, did not therefore represent destroying the "life" of the embryo.

"Ethical debate should not be reduced to 'potential for life'. Far more attention should be given to the environment," he said.

In particular, he argued that it would be justified to take stem cells from surplus IVF embryos created in the laboratory by injecting sperm into an egg.

Professor Don Evans of the Otago Bioethics Centre said there was evidence that stem cells from freshly fertilised embryos were more likely to grow than those taken from frozen IVF embryos.

He said it might therefore be better to take stem cells from surplus embryos as soon as they were fertilised, rather than waiting until the end of the IVF process nine months or more later. The head of the National Ethics Committee on Assisted Human Reproduction, Professor Sylvia Rumball, said her committee expected to complete a discussion paper in the next month on the use of embryonic stem cells.

Last month the committee gave Health Minister Annette King draft guidelines under which couples undergoing IVF could donate surplus embryos to other couples. Mrs King is expected to issue these for public comment.

Professor Rumball said her committee had not yet received any requests from New Zealand researchers to extract stem cells from human embryos.

But scientists at Auckland University have used stem cells from certain adult tissues to regrow brain cells, offering hope to victims of Huntington's disease.

Adult stem cell research is allowed because it does not involve destroying an embryo. But Professor Jones said there was evidence that adult cells could only replace other cells in a more limited way than cells taken from a new embryo.