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News in Brief
Stem-Cell Scientist Retracts Paper
In mid-December 2005, the prestigious journal Science complied with the request of world-renowned South Korean scientist Woo-Suk Hwang, D.V.M., Ph.D. to retract his June 2005 paper on cloning human embryonic stem-cell lines. The scientific community has accused Dr. Hwang of unethical and fraudulent research, including submitting falsified photographs of stem cells and paying women to donate eggs used in the research. Since Dr. Hwang made his request, he has resigned from Seoul National University (SNU).
In response to what appeared to be breakthrough findings which he published in Science last year, the research community initially heralded Hwang as the first scientist to successfully clone human embryonic stem cells. This dramatic achievement was expected to have promise in treating diseases in which certain cells are lost or damaged, such as Parkinson's. In his retraction, Hwang said that certain analytical tests used to confirm his findings could not be trusted. Just before Hwang's resignation, he admitted that nine of the stem-cell lines (11 were supposedly featured in the 2005 Science paper) were not clones. SNU launched a panel investigation into his work and reported in mid-January that there is no evidence that Hwang's team cloned human embryonic stem cells. The panel stated that the results of this paper, along with those of an earlier March 2004 paper published in Science (claiming that Hwang had cloned the first embryonic stem-cell line), were fabricated. Science retracted both of Hwang's papers in mid-January.
Hwang had also been accused of paying women for their eggs and using his employees' eggs in the study. The SNU panel concluded that Hwang did know about members of his research team donating eggs, which is considered highly immoral and unethical. With regard to the photographs, scientist Sun Jong Kim has alleged that Hwang paid him to forge photographs that supported the authors' claims. Before the retraction, Hwang's co-author from the University of Pittsburgh, Dr. Gerald Schatten, had requested that his own name be removed from the paper.
"The reaction to this news in the US may be that people will call for the Bush Administration to relax its restrictive policy on embryonic stem-cell research. It may help strengthen our conviction that the US should not be trying to outsource this kind of science, that we need to ensure the participation of what is by far the world's most prolific scientific engine," said Robin Elliott, PDF's Executive Director. "We do have to go back some steps and start over on this particular avenue that Hwang was exploring. Why should this not be done here?"
While the news of Hwang's retraction is a big disappointment to scientific and advocacy communities alike, the story may carry implications for the ways that scientific journals go about their work. The editorial staff at Science has noted that in the future it will do additional checks on files prepared in the Photoshop program and will investigate the review process that was followed in accepting Hwang's papers for publication.
Gene Therapy Trials Begin in Humans
A long-awaited human trial to test the potential of gene therapy in treating Parkinson's disease has begun. After researchers saw promising results in monkeys, they began to enroll several dozen patients in three trials to test the method of injecting a gene carried by a virus deep into the brain where Parkinson's occurs. Scientists will use the information from these studies only to determine the safety of gene therapy, and not to test whether it works. If results are positive, researchers will then continue to assess the potential of the mechanism for treating Parkinson's.
Current PD treatments suppress symptoms by mimicking dopamine or regulating the brain's up-take of it. Interventions that truly slow the course of the disease by protecting remaining neurons and preventing cells from dying have proved harder to develop. Gene therapy could offer that potential.
One of the most closely-watched approaches is being worked on at the University of California, San Diego and at Rush University Medical Center in Chicago (a recipient of one of PDF's Center Grants). The scientists are testing a nerve growth factor called neurturin, a protective substance that occurs naturally in the brain. In this study, the brains of 12 people with Parkinson's are injected with a harmless virus that carries the gene for neurturin. This method of delivery avoids some of the problems that were encountered with the infusion technique used in past trials of another, better-known, nerve growth factor called GDNF. Some scientists think that the infusion technique used in the GDNF trials lacks the capacity to deliver the required quantity of growth factor far enough into the brain. Amgen, Inc., the manufacturer, abruptly halted trials of GDNF in 2004 because of concerns about safety and efficacy.
Jeffrey Kordower, M.D., one of the leaders of the new human trial at Rush University, conducted earlier primate studies of neurturin and found that monkeys with Parkinson's-like damage improved within three months of receiving growth factor gene therapy. Dr. Kordower is a co-founder of Ceregene Inc., the company that is developing this method of gene therapy.
Scientists caution the PD community that while they are enthusiastic about gene therapy, the treatment remains highly experimental and has not yet been determined to be safe or useful in humans. Gene therapy also carries the risks that accompany any major brain surgery, including bleeding, infection and barriers to easy termination of the treatment if side-effects should occur.