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Stem Cell Breakthrough: Scientists Say New Procedure Preserves Embryos

Posted on: Friday, 11 January 2008, 09:00 CST

A team of scientists has produced the first human stem cells that do not destroy the embryos from which they're derived, saying the abundant lines are so viable and hardy that researchers "can start using them tomorrow."

Dr. Robert Lanza and collaborators at Advanced Cell Technology in Worcester, Mass., promised two years ago that they could produce stem cells through an embryo-sparing technique, and now they say the procedure works flawlessly.

A single cell is plucked from an embryo, which then is frozen for later implantation. When Lanza first announced using the procedure as a way to obtain human embryonic stem cells, he called it a proof of principle but acknowledged the technique was "not yet ready for prime time."

It is similar to a routinely used technique called preimplantation genetic diagnosis (PGD). Couples undergoing in vitro fertilization sometimes choose to have their embryos tested for genetic diseases, using PGD. The technique allows one or two cells to be plucked from early-stage embryos for genetic screening. Embryos that have lost a cell or two through the technique have developed into healthy children, Lanza said.

Now, in a study reported in the journal Cell, he and a team of scientists say the technology has produced healthy lines of embryonic stem cells without destroying the embryos.

"This time a single cell was removed from individual embryos, and the biopsied embryo continued to develop normally," Lanza said. The embryos from which a cell was taken were immediately frozen.

This is working technology that researchers "can start using tomorrow," Lanza said.

He hopes the first studies based on cells derived from the technique will be launched later this year. He and several collaborators hope to apply to the U.S. Food and Drug Administration for permission to test stem cells as treatments for disorders that cause blindness, particularly macular degeneration and retinitis pigmentosa. Later, he hopes to test stem cells derived from the technique to address spinal cord injuries.

"This kind of research has been held up for so long," Lanza said yesterday. "We desperately need new lines, and this is one way to get them."

In November, scientists in the United States and Japan announced a different way to obtain embryonic stem cells, coaxing them to develop from skin cells. The landmark discovery, which made headlines worldwide, revealed how skin cells retain the primordial blank slates known as stem cells. Scientists believe stem cells are capable of morphing into any kind of cells and can be used as replacements to generate healthy new tissue in the event of injuries or debilitating disease.

Despite Lanza's excitement, opponents of embryonic stem cell have lambasted his new technique and are not convinced that it passes their smell test for protecting human embryos. In 2006, Richard M. Doerflinger, deputy director of the Secretariat for Pro-Life Activities with the U.S. Conference of Catholic Bishops, called Lanza's embryo-sparing experiments "gravely unethical" because they involve thawing, manipulating and freezing human embryos.

Yesterday, Kathy Hudson, director of the Genetics and Public Policy Center in Washington, D.C., an affiliate of Johns Hopkins University, said Lanza's works engenders many questions.

"While he seems to have successfully solved some technical issues," Hudson said, "the ethical issues have not been solved."

In PGD, she said, embryo survival often depends on the skill of the person performing the procedure.

Source: Newsday, Melville, N.Y.

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