Boston, MA — Once the province of a handful of marginalized scientists, the cloning of human embryos is becoming increasingly common in laboratories around the world, with several scientific teams regularly producing cloned embryos and many more labs preparing to follow suit.
Many researchers believe that multiple US labs are quietly preparing to create microscopic human embryos to harvest their stem cells, which can be used to grow new organs and tissues for disease treatment. None of the mainstream researchers want to create a cloned human, but the science is still controversial.
Opponents unsuccessfully pushed for a ban on so-called therapeutic cloning in the US Senate last week, hoping to prevent repeats of the headline-grabbing experiment by Advanced Cell Technology Inc. of Worcester last fall, the first published account of human cloning in hopes of getting stem cells.
Cloning experiments already have proliferated abroad, notably in China and England, according to interviews with researchers. Many US scientists are simply waiting for some political calm before embarking on their own human cloning work, scientists said.
Even though polls show the American public opposed to human cloning, there may be no practical way to halt the practice worldwide.
''You're not going to be able to put a lid back on the jar or put the genie back into the bottle,'' said Michael Lysaght, director of Brown University's biomedical engineering program, who monitors trends in regenerative medicine.
Some researchers anticipate new accounts of human embryo cloning experiments being published in the near future. MIT biology professor Rudolf Jaenisch said he has reviewed several of these accounts, which describe the experiments in detail.
The University of Connecticut's Dr. Xiangzhang Yang, another cloning specialist, said he has been briefed on the human cloning work in ''half a dozen labs'' in China, and is urging his colleagues there to seek publication of their work in Western peer-reviewed journals. At least one of the labs successfully cloned a human embryo before Advanced Cell Technology, said Yang, and all have conducted embryo cloning experiments numerous times.
In England, where embryo-related research has won government approval, a London academic teaching hospital and a Scottish research institute have obtained government licenses to conduct embryo cloning experiments, according to officals at the Human Fertilization and Embryology Authority, the British government agency that monitors embryo research. In addition, Scotland-based cloning pioneer Ian Wilmut, whose work produced Dolly, a lamb and the first cloned mammal, also has applied for a license.
To date, only ACT has published a paper describing human embryo cloning, in an obscure Internet journal. Many scientists thought the study premature because ACT scientists could not extract stem cells from the cloned embryos — the goal of human embryo cloning researchers. In addition, scientists seek more efficient cloning techniques since the majority of attempts fail. These repeated attempts will undoubtedly involve more destruction of human life.
Scientists overwhelmingly oppose implanting cloned embryos in women to produce babies, called reproductive cloning. Several maverick researchers claim to have implanted women, though no proof exists. However, many mainstream scientists worry that such attempts could proliferate as cloning becomes widespread and researchers become more proficient.
In therapeutic cloning, which seeks medical cures, genetic material from a patient is placed into a hollowed-out egg, then artificially stimulated to grow, creating an embryo genetically identical to the patient. Researchers hope to extract stem cells from these week-old embryos, then mold the flexible cells into easily-used replacement tissue for patients. But the process destroys the human being, ethically troubling many.
In the United States, these ethical qualms have complicated research. Last month, the University of California at San Francisco admitted, after media inquiries, its researchers conducted a cloning experiment that failed. The work was kept quiet to avoid political controversy, explained UCSF administrators. Until then, ACT was the only group to publicly admit to embryo cloning.
Many biotech specialists believe other US labs and companies have cloning experiments underway.
''I suspect there are more groups than we know who are actually working on therapeutic cloning,'' said Jean-Francois Formela, a Boston-based general partner with Atlas Venture, an investment firm specializing in technology, which nonetheless remains skittish about pouring money into cloning science.
The ethical controversy has kept many other interested US researchers away, at least for now.
Johns Hopkins University stem cell pioneer Dr. John Gearhart, when asked whether he planned human embryo cloning work, said, ''Yes, but I do not know when we would [or] could begin.''
''You would have to submit a very sound proposal and it would be reviewed with a fine-toothed comb'' by the university, he said.
At Harvard University, the Stem Cell Research Committee was created last year to inspect such proposals. Ten members, drawn from various disciplines, sit on the ad hoc board, according to committee chair and Harvard biologist Richard Losick. To date, they have reviewed only one stem cell research proposal, he said. No cloning proposals have crossed their desk.
However, many labs in the United States, and elsewhere, easily could launch cloning experiments, said UConn's Yang.
''Technically, it's not really a problem,'' he said.
Yang's lab includes a graduate student who previously worked with Dr. Guangxiu Lu of the Xiangya Medical College, located about 800 miles from Beijing. Lu has been cloning human embryos regularly for more than a year, said Yang, who has contacted her through the student. Yang has also heard, from his Chinese contacts, of at least five other labs that have cloned human embryos on several occasions. He is attempting to lure some of them to the United States to present their work to Western scientists.
Yang said he would consider a human embryo cloning experiment only if funding came from the US government, which is unlikely while President Bush, an embryo cloning opponent, sits in the White House.
MIT's Jaenisch, who has made numerous breakthroughs in animal cloning, said he too would not proceed on human embryo work without government funds.
''It is such a contentious and controversial issue, I think it would be extremely important that this research is done in the public sector, where it is open to public view, but also at the most prestigious universities, where it is heavily scrutinized under the highest standards,'' he said.
ACT funds its own experiments, while UCSF received money from the Geron Corp., a Menlo Park, Calif.-based biotech firm. Charities also are lining up to bankroll cloning experiments.
Dr. Robert Lanza, ACT's chief scientific officer, expects domestic competition. ''I think everyone is taking a sit-and-wait approach right now,'' he said. ''But this is the future of medicine. Groups will enter the field, I'm sure.''
See the Boston Globe for more coverage.
(This article courtesy of Steven Ertelt and the Pro-Life Infonet email newsletter. For more information or to subscribe go to www.prolifeinfo.org or email infonet@prolifeinfo.org.)
