Britain approved to produce stem cells without "killing" embryos

In the "virgin breeding" method, the stem cells are produced without using sperm

 By: Yuval Dror 
  
The debate on the issue of embryonic stem cells was rekindled last week. The British Fertilization and Embryology Authority (HFEA) granted a license to the Roslin Institute to begin research aimed at producing embryonic stem cells using a technique known as "virgin reproduction" (parthenogenesis). The British researchers claim that the new technique settles the ethical debate surrounding the production of the cells, because no sperm is used in it.

Embryonic stem cells are "non-identity" cells and their uniqueness stems from their ability to become any of the body's tissues. The biologists hope that it will be possible to use them to produce implants and use them to repair damaged tissues in the body. However, despite the scientific "promise" inherent in them, in more than 35 countries there are laws that limit embryo cloning. For most of them, the prohibition refers to cloning for reproductive purposes, but some prohibit cloning even when the purpose is biomedical research (production of embryonic stem cells from human embryos for research purposes). The reason: opposition from religious and conservative factors who claim that the production of the cells involves "killing" embryos.

To date, the scientists have produced the cells from eggs taken from women in fertility clinics, and left unused after the couple managed to have a baby. In the process of producing the embryonic stem cells, the embryo is destroyed, and according to some conservative sources, from the moment the sperm fertilizes the egg, a living being is created - even if it took a few hours or days.

The UK is one of the only countries that allows embryo cloning research. The Bush administration, for example, opposes cloning of any kind, and has even reduced the budget allocated to research in this field. In Germany, the law prohibits the production of stem cells from embryos created in the country - but allows them to be imported. As part of this, cells produced at the Technion and the Rambam Hospital in Haifa were transferred to Germany.

Now the British researchers claim that the production of the stem cells through the virgin reproduction technique settles the ethical debate. The technique causes the egg to divide and begin to form an embryo as if it had been fertilized by a sperm - although in practice no sperm was used.

A normal female egg contains a nucleus with 46 chromosomes. After a natural process known as "reductive division" the egg gets rid of 23 chromosomes so that it can absorb the 23 chromosomes found in the sperm. In the method of virgin reproduction, an egg is taken before the reduction division; Through an electric current or chemicals that change the biochemical actions in the egg, the nucleus is made to behave as if the 46 chromosomes it contains were created as a result of sperm fertilization - thus causing it to start dividing. After 5-4 days, an embryo-like cell mass is formed, from which the stem cells are harvested.

Experiments carried out with this method in animals revealed that, although the cells develop, they die after a few days. According to the supporters of the method, this is an advantage: it causes the cells to divide, but they cannot develop into a normal embryo - and hence there is no fear of killing the embryo.

However, it is not clear whether the scientists will succeed in producing human embryonic stem cells. "Scientists do not know if duplicating the genetic load from a single parent will provide normal embryonic stem cells," says Hermona Sorek, professor of molecular biology at the Hebrew University. "There are genes whose expression is determined by the side from which they were received: the father or the mother. Therefore, the scientists claim that there is no fear that a normal embryo will develop, since they use a chromosome system from only one side." However, according to Sorek, the use of one system may cause normal cells not to develop, from which healthy tissues can be grown.

Dr. Carmel Shalu, Director of the Ethics and Health Rights Unit at the Gartner Institute, claims that even if one ethical problem is solved, there are still other ethical problems. According to her, "the issue of receiving the eggs remains." In an article published in the magazine "Scientific American" examples of the issue were given refers to his. Normally, a woman produces one or two mature eggs in each menstrual cycle. To increase this to the appropriate number of eggs for use in the study, drugs are given Irritants that in rare cases can cause liver damage, kidney failure or stroke. According to some studies, there is also a link between these drugs and an increased risk of ovarian cancer. The procedure to remove the eggs also carries risks.

"The researchers will be required to keep a stock of eggs. Who will donate them?" asks Dr. Shalu. Indeed, the Roslin Institute has announced that in order to start experiments, it will have to wait for a license that will allow it to hold a large number of eggs. In the meantime, only eggs left in fertile laboratories will be used.
The one who will lead the scientists is Prof. Ian Willems, who cloned Dolly the sheep. However, the license given to the institute allows the use of cells that will be produced for research purposes only (and not for reproductive purposes).

The granting of the license also has business consequences. The Roslin Institute is funded by the biotechnology company "Gron", which specializes in the development of cancer drugs. In the company's announcement, it was stated that the purpose of the research is to produce a new series of embryonic stem cells and to discover ways in which they can be produced and preserved over time. After the announcement, the company's stock jumped by about 20%, but since then it has lost 9%
 
 

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