The South Korean researchers who made history this week in creating human embryos through cloning and extracting viable stem cells say they adamantly oppose cloning to make babies.
“We are in the position against reproductive cloning,” Woo Suk Hwang said Thursday at an American Association for the Advancement of Science meeting in Seattle.
Hwang and Shin Yong Moon, both of Seoul National University, led the team that announced the first successful demonstration of human “therapeutic cloning.”
Scientists and patient advocates heralded the development as a step toward potential therapies to replace defective cells, while abortion opponents and others raised ethical questions.
The monumental research, published Thursday in the journal Science, involved collecting 242 eggs from 16 women. Researchers removed genetic material from the eggs and replaced it with DNA from ovary cells of the same women. Using special techniques to mimic fertilization and encourage cell growth, the scientists produced early-stage embryos called blastocysts. No male sperm were involved, thus no fertilization in the traditional sense was achieved.
Stem cells removed from the blastocyst were grown into other kinds of cells in a lab dish and in mice, proving the feasibility of developing the malleable cells into treatments for diabetes, Parkinson’s disease, spinal-cord injuries and other conditions.
Some people worry that by providing a detailed “recipe” for cloning in their published report, the Korean scientists have encouraged cloning to create babies, perhaps by renegade scientists.
But Hwang said he encouraged the move last year by the South Korean government to ban reproductive cloning, and he called Thursday for all nations to follow suit. The U.S. House of Representatives has approved a bill to forbid all cloning for any purpose, but a similar measure has stalled in the Senate, where many senators want to preserve cloning — such as Hwang’s technique — for medical research.
Donald Kennedy, editor in chief of Science and former president of Stanford University, said the cloning steps outlined in the Korean team’s paper are only a fraction of the measures necessary to create babies.
“It is a recipe only in the sense that ‘catch a turtle’ is the recipe for turtle soup,” Kennedy said. “There is much difficulty that would remain to anybody who would try to use this technology as a first step to reproductive cloning.”
The Korean scientists, who said their research was privately funded by a group they would not name, also said they would not commercialize their stem-cell lines.
Despite the assurances against reproductive cloning, the Christian Medical Association in Washington condemned the research, saying it destroys human life.
“We know from animal cloning that the technical problems and dangers associated with cloning will never produce therapies that these researchers speculate could be applied to human beings,” said Dr. David Stevens, executive director of the association.
In Atlanta, officials at the nationally renowned Shepherd Center, which treats people with spinal-cord injuries and other neurological conditions, said the therapeutic cloning development could spur progress toward therapies to regenerate nerve cells to treat paralysis.
The long-term hope is to regenerate cells that control movement in the Central Nervous System, said Michael Jones, vice president for research and technology at the Shepherd Center.
But in the short term, cell therapies to restore damaged skin, muscle or bone might be a more realistic goal because those cells are somewhat less complicated than nerve cells, Jones said. Such therapies could treat bedsores or muscle Atrophy resulting from paralysis, or enable fresh bone to replace metal rods implanted in patients to help them sit upright.
“Even if we never learn how to regenerate nerve tissue, there will be applications of stem cells that would be relevant to spinal-cord injury,” Jones said.
Experts estimate that clinical trials of embryonic stem-cell treatments are at least five years away.
By DAVID WAHLBERG – mailto:firstname.lastname@example.org
The Atlanta Journal-Constitution