Scientists yesterday reported that 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 with cloning and stem 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 diseases because embryos have to be 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.
The rest of the embryo retains the 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, consisting of 100 to 150 cells, after about five days of development. Harvesting the cells kills the embryo.
“We have demonstrated, for the first time, that human embryonic stem cells can be generated without interfering with the embryo’s potential for life,” said Dr. Robert Lanza, vice president of research and scientific development at the company and the study’s senior author.
But few 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 moral grounds by Richard M. Doerflinger, deputy director of the U.S. Conference of Catholic Bishops’ Secretariat for Pro-Life Activities.
“It is widely believed that one cell of a very early embryo may separate and become a new embryo, an identical twin,” he said yesterday.
The company’s research produced two viable stem-cell lines from 16 embryos.
“The experiment itself is gravely unethical, because it involved thawing and manipulating 16 human embryos and then discarding them,” Mr. Doerflinger said. “By picking single cells from eight-celled embryos and culturing them overnight, it is possible the researchers created 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.”
In the report in Nature, he said individual blastomeres in embryos that 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 in-vitro fertilization, when one blastomere in an eight-cell embryo is removed and tested for genetic disorders. If no defect is found, the embryo, now with seven cells, can be implanted in the mother.
Federal funding is not available for most research involving embryonic stem cells because of ethical concerns.
White House spokeswoman Emily A. Lawrimore said it is too soon to know whether studies using the new technique would qualify for federal funds.
“Any use of human embryos for research purposes raises serious ethical concerns. This technique does not resolve those concerns, but it is encouraging to see scientists at least making serious efforts to move away 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 a stem cell. This work has to be confirmed.”
Dr. Lanza said the company is eager to make its new technique available to the scientific community at little or no cost. He also said he is “absolutely certain” the results will be confirmed.
In late 2001, Advanced Cell Technology reported that it had cloned the first human embryo. It said its goal was to grow stem cells for medicine, not to create cloned humans. Pro-life advocates were outraged, and the company’s research was belittled by some in the scientific world.
“This company is not moved by moral arguments but by market arguments. A small shadow hangs around ACT that has to be lifted before jumping up and down” in celebration of its blastomere breakthrough, said Mr. Caplan.