In a breakthrough that might give stem cell research advocates a weapon to fight with, two independent research studies have obtained embryonic stem cells without destroying the embryos. Even though the research involved mice embryo, they are capable of taking the stem cell debate to another plane.
The two studies, one by researchers at Advanced Cell Technology in Worcester, Massachusetts, and the second by those at the Massachusetts Institute of Technology, have shown that it is possible to extract stem cells while sidestepping the ethical debate.
“No one has ever done this before. What we are trying to do here is to create a stem cell line without injuring an embryo. Our cells can go on to become a healthy, kicking baby,” said Dr Robert Lanza of the Advanced Cell Technology, and the lead researcher of one of the studies.
His team used a technique, called pre-implantation genetic diagnosis (PGD), which is used for testing embryos for genetic deformities in IVF clinics. Under this technique, a single cell, called blastomere, is extracted from an embryo comprising eight cells and tested for genetic abnormalities. If none is found, the embryo, which remains unharmed, is planted in the womb.
According to Dr Lanza, the single cell extracted through the technique can be used for creating other stem cells from the single cell in a laboratory. The team used 125 blastomeres for producing five cell clusters that exhibited all properties shown by embryonic stem cells.
“Many people including President (George W) Bush are concerned about destroying life to save life. But this is not destroying life because the embryo is fully capable of implanting,” Dr Lanza asserted. “The ability to generate human embryonic stem cell lines from PGD blastomeres could circumvent the ethical concerns voiced by many, and allow the banking of cell lines for children born from transferred embryos,” he added.
To test how well the embryos used took to the womb, the researchers planted them into volunteers and found that the embryos grew into a healthy baby 49 per cent of the times. This percentage is consistent with that shown by embryos that contain eight cells.
In the second research by the Massachusetts Institute of Technology, a team, comprising Rudolf Jaenisch and Alexander Meissner, tested a hypothesis that was offered by President's Council on Bioethics member Dr William Hurlbut.
Under the study, this team used a technique called 'altered nuclear transfer' to genetically alter the egg cells of mice to make them capable of producing embryonic stem cells, but not of growing into embryos. The researchers took the nucleus of an adult cell containing DNA and planted it into an egg cell whose nucleus was scraped off.
A gene, Cdx-2, responsible for attaching the cell to the uterus, was rendered ineffective as a result of this transfer. However, the cells, which were not potential babies, grew stem cells that were harvested by the research team. “Our experiments are very clear. You inhibit this gene and you get a clone that has no way of ever implanting. But this clone can make embryonic stem cells,” said Jaenisch.
While some scientists hailed the research, many remained skeptical as to how helpful this study would be in abating the debate. “It's cool science. It broadens the debate. But it will solve problems for some, and make problems for others,” said Larry Goldstein of the University of California in San Diego. “I don't see how it solves any ethical problems. The people who object are opposed to the whole cascade of reproductive medicine . . . they are not going to be won over by embryos that are not viable for a pregnancy,” said Stephen Minger, a stem cell research advocate from King's College in London.
But, stem cell research critic Tadeusz Pacholczyk from the National Catholic Bioethics Center in Philadelphia, felt differently. “I am very encouraged. We may be able to work around this with some creativity and good will,” Pacholczyk said.
