Some concerned about inability to use cell lines fromsomatic cell nuclear transfer and other sources
“The majority of Americans—from across the political spectrum and all backgrounds and beliefs—have come to a consensus that we should pursue this research. That the potential it offers is great and, with proper guidelines and strict oversight, the perils can be avoided.”—President Barack Obama, March 9, 2009, in his speech announcing the lifting of the ban on federal funding for embryonic stem cell research
After signing an executive order to allow federal funding for embryonic stem cell research, President Obama asked the National Institutes of Health (NIH) to develop specific guidelines for such research. The NIH released its final guidelines on July 6, 2009 after a public comment period on a set of draft guidelines.
For members of the research community, the final guidelines brought both good and bad news. Scientists initially were concerned by indications in the draft guidelines that all cell lines developed prior to July 6, 2009 would have to meet a new NIH-developed informed consent process. That would have meant many of the existing cell lines used for research would not have qualified for federal funding. Many people and organizations protested this rule during the public comment period, and the NIH changed the guidelines to allow a different course of approval for cell lines developed prior to July 6, 2009.
“Existing lines will be reviewed by aworking group of an NIH advisory committee, and if they are found to represent the principles of informed consent outlined under the guidelines, they will be approved,” says NIH Acting Director Raynard S. Kington, MD, PhD.
The same will apply to cell lines donated outside the United States, he adds, noting that approved stem cell lines with be posted on an NIH registry.
“The new guidelines are amajor step forward for stem cell research,” says George Daley, MD, PhD, a leader in the field and associate professor of biological chemistry and molecular pharmacology and pediatrics at Children's Hospital Boston and Harvard Medical School in Boston, Massachusetts. “The onerous requirement for explicit language of informed consent [in the draft guidelines] has been replaced by a deliberative process that will approve lines using sound judgment and discretion.”
Dr. Daley's recent stem cell research relates to a protein, Lin28, that he and his colleagues have shown modulates microRNA levels and that is involved in several late-stage cancers, including blast crisis stage chronic myelocytic leukemia.
Limiting the Research
Dr.Daley predicts that “a treasure trove” of lines will be made available to the stem cell research community, which will translate into vital new knowledge.
Nevertheless, he and others have some concerns about the new guidelines, which allow research only on cells from leftover embryos from fertility clinics that otherwise would have been thrown away. The guidelines do not, however, allow for research using cell lines made explicitly for research or for medically valuable lines made by parthenogenesis, directed in vitro fertilization, and somatic cell nuclear transfer (SCNT).The last is a technique in which the nucleus of a somatic cell (any cell of the body except sperm cells and egg cells) is injected, or transferred, into an egg that has had its nucleus removed. The nucleus is reprogrammed by the host cell and forms a blastocyst—an early stage embryo that is nearly identical to the donor cell. This process can be used to create disease-specific cell lines on which to conduct research and test therapies. Although it is therapeutic (not reproductive) cloning, some have raised ethical concerns about the technique.
“It's hard to do, and no one has made it efficient enough to do it in humans, although it has been done in mouse systems and primate eggs,” notes Irving Weissman, MD,director of the Stanford Institute for Stem Cell Biology and Regenerative Medicine in Stanford, California, and president of the International Society for Stem Cell Research.
“If the NIH guidelines allowed the ability to produce SCNT-derived lines, we could go to each of the human cancers and recreate the changes that occur from the starting stage of a stem cell to the development of a cancer cell,” he adds.
Dr. Weissman's research includes the biology and evolution of stem cells and progenitor cells, mainly blood forming and brain-forming cells. He also is engaged in isolating and characterizing the rare cancer and leukemia stem cells as the only dangerous cells in these malignancies, especially with human cancers.
If SCNT were efficiently developed for humans, scientists could study the pathogenesis of many complicated diseases, Dr. Weissman notes, adding that it ultimately could lead to new cancer therapies.
“There is no scientific reason why you wouldn't want those lines produced,” he says. “That's exactly what President Obama said to a rousing standing ovation at the National Academy of Sciences—that he wouldn't put ideology or politics in the way of good science.”
Although the NIH guidelines are an advance, they are “not the kind of advance that was up to the promise of President Obama's speech,” Dr. Weissman concludes.
Meanwhile, researchers in California will continue to work in this area through the support of the California Institute of Regenerative Medicine, which was created in 2005 by Proposition 71 to counteract the effect of President George W. Bush's limits on federal funding of stem cell research.
Dr. Kington adds that the NIH was instructed to continue reviewing other techniques such as SCNT as the country's ethical discussions on stem cell research continue.
“We'll follow the discussion of standards and the scientific evolution of the research and, when appropriate, we will review our guidelines,” he says.
After President Obama's executive order, the NIH released its final guidelines for federal funding of stem cell research on July 6, 2009.
The guidelines allow for cell lines produced prior to July 6, 2009 to undergo review for approval by an NIH working group. The cell lines must comply with the principle of informed consent outlined in the guidelines.
The NIH will list approved cell lines in a posted registry.
The guidelines do not permit federal funding of SCNT research, a technique that many scientists say would help them understand the pathogenesis of major diseases such as cancer.