A survey of scientists studying stem cells suggests that the absence of clear federal regulations governing the use of embryonic stem cells and uncertainty over funding for research is generating serious delays in this promising field, and discouraging scientists from studying these controversial cells.
“Frequent policy changes and uncertainty over future policy have been a near constant for stem-cell researchers over the last decade or so,” says Aaron Levine, assistant professor of public policy at the Georgia Institute of Technology, who conducted the research. “That has affected both scientists studying embryonic stem cells and those working on less controversial cell types, who we might expect not to be as affected.”
According to the survey, published today in the journal Cell Stem Cell, nearly half of the scientists questioned who study embryonic stem cells or are considering using the cells said that the climate of uncertainty has had a substantial impact on their research. Many said they had delayed the start of new projects or were considering moving away from the field altogether. While many experts in the field had predicted these negative outcomes, the survey is one of the first efforts to systematically assess the effects of U.S. policy regarding stem-cell research.
In the last year, the U.S. Food and Drug Administration has given the green light to three clinical trials of new therapies derived from embryonic stem cells: one for spinal cord injuries and two for blindness disorders. But both of these emerged from companies with private funding. Scientists worry that the restrictive research climate will hamper further progress, slowing or stopping the basic research from which most clinical trials emerge.
Embryonic stem cells are considered one of the most promising tools for regenerative medicine, especially as a source of replacement tissue, thanks to their ability to replicate themselves and to grow into any cell type in the human body. But the topic has been fraught with controversy because deriving new lines of embryonic stem cells requires the destruction of human embryos.
Stem-cell researchers experienced a brief bout of optimism two years ago when President Obama signed an executive order ending a restrictive policy enacted in 2001 by President Bush. That policy had blocked federal funds from being used to study most human embryonic stem cells and led to a patchwork of state regulations governing funding for the field. Current federal policy permits federal funding for research using existing cells but not the derivation of new cells.
The optimism came to an unexpected end last August when a federal judge issued an injunction blocking federal funding for any research involving embryonic stem cells, pending the result of a lawsuit claiming such funding to be illegal. As a result, research and grant reviews at the National Institutes of Health (NIH), the nation’s largest biomedical funding agency, came to a halt, and scientists who had federal funds were left wondering what to do. The Obama administration successfully appealed the injunction in September, but ongoing uncertainty over the timing and outcome of the lawsuit means that confusion remains.
“We went back to things as they were before, but with this looming danger that our research may become illegal,” says Jeanne Loring, director of the Center for Regenerative Medicine at Scripps Research Institute in La Jolla, California. Loring says she will no longer apply to the NIH for embryonic stem-cell grants. Instead, she will rely on state or private funding. (In 2004, the state of California approved $3 billion to fund stem-cell research.)
But researchers in most other states don’t have this option. Researchers at the University of Wisconsin, for example, where human embryonic stem cells were first isolated more than a decade ago, and which runs an NIH-funded repository of embryonic stem-cell lines, rely heavily on federal funding.
The survey, of 370 U.S. stem-cell researchers, found that this uncertainty had a greater impact on research than did the August ruling. Nearly half of scientists who work on stem cells, but not human embryonic stem cells, said the uncertainty has had a moderate to substantial impact, the most common being the delay of new studies using embryonic stem cells. Thirty-four scientists said they were moving away from embryonic stem-cell research, some switching to non-human stem cells or induced pluripotent stem cells (iPS cells)—adult cells that have been genetically or chemically reprogrammed to behave like stem cells—even if these cells are less appropriate for answering questions asked in their research. “If people are being forced away from using the best tools, that’s a problem,” says Levine.
While iPS cells may provide a promising alternative to embryonic stem cells in the long-term, it’s still unclear how closely they resemble their embryonic cousins. A number of recent studies suggest that reprogramming cells into a stem-cell-like state is an incomplete process that may limit the usefulness of iPS cells.
The survey’s results also cast doubt on one of the assertions that allowed the original lawsuit to be brought. The suit claimed that two plaintiffs in the case, both adult stem-cell researchers, could be harmed by the current funding policy, which would increase competition for grants from scientists studying embryonic stem cells. But only four of the 87 non-embryonic stem-cell scientists who gave additional details on their responses reported a positive impact of the judge’s ruling, while six described a negative impact, such as lost collaborations. “That suggests we should be thinking about harm a bit more broadly in context of this case,” says Levine.