Embryos preserved in stem-cell creation
ScientistsonAug.23reportedthat they have devised a way to create human embryonic stem cells that does not harm embryos.
Researchers with Advanced Cell Technology, a California-based biotechnology firm that has been on the cutting edge of experimentation withcloningandstem cells, disclosed their latest findings online in the journal Nature.
They say their technique offers a potential solution to the political and moral debate over using embryonic stem cells to treat life-threatening diseasesbecauseembryoshavetobe destroyed.
The company says its technique takes just a single cell, or blastomere, from a two-day-old embryo, after the fertilized egg has divided into eight cells. They use the blastomere to seed a line of stem cells, which can then grow into any kind of human tissue.
Therestoftheembryoretainsthe capability to grow into a healthy human, according to the biotech firm, which operates in Alameda, Calif., and Worcester, Mass.
The current procedure requires the destruction of embryos, consistingof100to150 cells, afterabout five daysofdevelopment.Harvestingthe cells kills the embryo.
“We have demonstrated, for the first time, that human embryonic stem cells can be generated without interfering withtheembryo’s potential for life,” said Dr. Robert Lanza, vice president of research and scientific development at the company and the study’s senior author.
Butfew in the scientific, bioethics or pro-life community think the new technique will end the debate.
“It’s scientifically interesting [. . .] but it’s not going to settle the debate. If one believes an embryo should be accorded the rights of protection of a person, why is it more [morally acceptable] to extract one cell from an embryo than to extract many cells?” said B.D. Colen, spokesman for Harvard University’s Stem Cell Institute.
Cell extraction was criticized on moralgroundsbyRichardM.Doerflinger, deputy director of the U.S. ConferenceofCatholicBishops’Secretariat for Pro-Life Activities.
“It is widely believed that one cell ofaveryearlyembryomayseparate andbecomeanewembryo,an identical twin,” he said.
The company’s research producedtwoviablestem-celllinesfrom 16 embryos.
“The experiment itself is gravely unethical, because it involved thawingandmanipulating16humanembryos and then discarding them,” Mr. Doerflinger said. “By picking single cells from eight-celled embryosandculturingthemovernight, it is possibletheresearcherscreated and destroyed as many as 91 additional very early embryos to get two new cell lines.”
But Dr. Lanza, in a telephone interview, said such criticisms show “scientific ignorance.”
InthereportinNature,hesaid individualblastomeresinembryosthat have only eight to 16 cells “have never been shown to have intrinsic capacity to generate a complete organism in any mammalian species.”
The researchers used a fertility treatment known as preimplantation genetic diagnosis to create stem cells. This technique is used in invitro fertilization, when one blastomere in an eight-cell embryo is removed and tested for genetic disorders. If no defect is found, the embryo,nowwithseven cells, canbe implanted in the mother.
Federal funding is not available for most research involving embryonic stem cells because of ethical concerns.
WhiteHousespokeswomanEmily A. Lawrimore said it is too soon to knowwhetherstudiesusingthenew technique would qualify for federal funds.
“Any use of human embryos for researchpurposesraisesseriousethical concerns. This technique does not resolve those concerns, but it is encouraging to see scientists at least makingserious efforts to moveaway from research that involves the destruction of embryos,” she said.
Arthur Caplan, head of the bioethics center at the University of Pennsylvania, said, “Being able to generate a stem cell doesn’t mean that what you’ve produced is going to work as astem cell. This workhas to be confirmed.”
Dr. Lanza said the company is eager to make its new technique availabletothe scientific community at little or no cost. He also said he is “absolutely certain” the results will be confirmed.
Robert Lanza of Advanced Cell Technology led the research that produced a technique to withdraw a single cell from a two-day-old embryo in order to create stem-cell lines. The process allows the embryo to continue developing into a human being.