Although the Obama administration is still in its infancy, important strides have been made to fulfill the promise President Obama made in his inaugural address to, “restore science to its rightful place.” First, the $787-billion economic stimulus package has infused $10.4 billion into the National Institutes of Health (NIH) and another $3 billion into the National Science Foundation (NSF). Given that the NIH and NSF fund the overwhelming majority of the basic science research in the US, this financial support is a promising sign of progress toward reinstating US biological research as a world-premier engine for healthcare innovation and a major driver of economic stimulation.
Additionally, a significant change in policy is being implemented that aims to influence the ways politics impacts science to further support progress while still demanding accountability from scientific researchers. Most recently, this has been made apparent by the March 9th announcement of Obama’s executive order to reverse restrictions on federally funded stem cell research.
Stem Cells: What’s the Big Deal?
There are two general aspects that make stem cells so important in the biomedical research and political arenas: (1) their unmatched potential for therapeutic benefit and (2) the question of the moral permissibility of generation and utilization of embryonic stem cells.
What therapeutic benefits do stem cells have to offer? Stem cells are defined as those cells that can both self-renew and give rise to (i.e., “differentiate” into) other cells with different functions. There are many kinds of stem cells, each with specific sets of cells they can make. In other words, the various kinds of stem cells differ in their degree of “potency”. You may have heard of “multi”-potent or “toti”-potent stem cells. These terms signify how many different kinds of cells a particular stem cell can generate. Blood stem cells (hematopoietic stem cells) are stem cells because, when they divide, they not only give rise to more hematopoietic stem cells (i.e., they self-renew) but also generate all the blood cells (red blood cells, white blood cells, and platelets). However, these hematopoietic stem cells cannot give rise to kidney cells or heart cells, for example. Therefore, blood stem cells are multi-potent, but not toti-potent. This latter term is reserved for stem cells that can give rise to all the cell types in the body. Embryonic stem cells are toti-potent, giving them the unique ability to ultimately generate all the cells of the human body.
Aside from the quest for greater understanding of biology, why do researchers study stem cells? The major drive in biomedical stem cell research is to develop new therapies for patients who could benefit from tissue regeneration or repair. The quality of life of patients with problems such as spinal cord injury or organ failure would be greatly improved if we could learn to harness the toti-potent power of embryonic stem cells to induce differentiation into neuronal cells or organ-generating cells that can subsequently be given to the patient to restore proper functioning or replace damaged tissues. This type of therapy eventually could be relevant for treatment of heart disease, Parkinson’s disease, diabetes, organ replacement, spinal injury, stroke, etc. As you may have learned in the news or in one of our own SITNFlash articles (July 2007), scientists have now developed methods of generating cells that behave similarly to embryonic stem cells but are derived from ordinary skin cells instead of from an embryo. Although very exciting, this novel technique must be further refined since it currently requires the use of potentially harmful viruses to introduce the essential factors that promote conversion from normal skin cells to toti-potent stem cells.
Why is the moral permissibility of stem cell research questionable? The controversy over stem cell research arises due to the source of embryonic stem cells: human embryos. Opponents of embryonic stem cell research argue that generation of human embryonic stem cells (hESCs) is not morally permissible since it harms or destroys embryos, which they maintain to be a human life at the time the egg is fertilized. Proponents of embryonic stem cell research often disagree with the notion that life begins at fertilization. This fundamental difference in viewpoint leads to heated debates and the interjection of politics into science in a prohibitive way. However, many hESC research advocates argue that the debate about when life begins is not critical to this issue since fertility clinics provide an already-established, socially accepted source of embryos from which hESCs can be isolated. Fertility clinics around the world are faced with possessing more fertilized eggs than can or will be used. Often, these embryos are simply discarded. Interestingly, there is little public interest in shutting down fertility clinics that routinely destroy unneeded, excess embryos. The response from opponents to this line of logic is often that it is still objectionable to use these embryos since it condones the destruction of embryos.
A Bit of Policy History
Prior to 1995, there was no legislation on stem cell research since this field of research had not been well-established. In October 1995, however, Congress placed a ban (referred to as the Dickey-Wicker amendment) on federally-funded human embryonic stem cell research that specified that no funds could be provided for research in which, “a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death…” (H.R. 3010, Sec. 509). Up until 2001, no hESC research was funded by the NIH. On August 9, 2001, however, former President George W. Bush announced that federal funding could support hESC research but only when performed on stem cells already in existence at the time of his announcement. No newly developed hESCs could be studied using federal funds. Although this was an improvement in policy for scientists studying stem cells, it severely limited the progress that could be made since the quality and availability of some of the stem cell lines was questionable. Two times (once in July 2006 and again in June 2007) after the Bush limits were put in place, the House and Senate approved the Stem Cell Research Enhancement Act (H.R. 810), which would have supported research on hESCs (regardless of when they were isolated) as long as the embryos from which the stem cells were derived were from unpaid, consenting individuals who would otherwise have discarded the unused embryos after fertility treatment. Both times Bush vetoed the bill.
After only seven weeks in office, President Obama issued an executive order lifting the limits imposed in 2001. This means that as soon as the NIH drafts guidelines, researchers will now be able to receive federal funding for studies involving existing hESCs that were isolated using private funds, even if isolation was after August 9, 2001. However, the Dickey-Wicker amendment banning use of tax money to generate new hESC lines is still in place. President Obama has not taken a position on the ban and has no power to overturn it. It is left up to Congress to decide whether to overturn the Dickey-Wicker ban. As it currently stands, hESC researchers in the US will have more opportunities to make cutting-edge discoveries using hESCs generated using private funds, but they will not be able to create their own hESC lines using federal funds.
It is clear from President Obama’s executive order that his administration is supportive of stem cell research.
What the Future May Hold
A first test of the therapeutic potential of hESCs will be the FDA-approved phase I clinical trial by a company called Geron to test the safety of injecting neuronal progenitor cells into the spinal cords of a small number of patients with recent spinal cord injuries. Based on animal studies, the hypothesis is that these injected cells will be capable of generating a new nerve coating called myelin to facilitate repair. Despite these and other exciting steps forward, the scientific community must remain diligent about putting science first to ensure that sufficient evidence is obtained prior to extensive use of hESC-derived therapies so that potential adverse medical side effects (e.g., tumor generation) are thwarted. Still, the future is bright for novel biological insights and truly revolutionary clinical applications.
With all this optimism about a renewed sense of priority for science, there is an unprecedented opportunity for engagement between scientists and non-scientists. We hope that you will also be inspired by this environment to learn more about the science funded by your tax dollars. To get you started, try attending educational seminars and workshops or contacting researchers to learn more about their research. Likewise, scientists must reach out more to explain their research to the public and help generate a realistic picture of what we might expect in the coming years.
If you’re interested in learning more about your elected officials’ views and voting record on these and other topics, visit the Scientists and Engineers for America website at www.sharp.sefora.org. To read and hear more about stem cells and stem cell research, please visit the Science in the News archives for SITNFlash articles, presentations, and podcasts related to the topic at www.sitn.hms.harvard.edu.
–Carrie L. Lucas, Harvard Medical School
For More Information:
Article on stem cell policy changes by the Obama administration from the New York Times. March 6, 2009. By David Stout and Gardiner Harris:
< http://www.nytimes.com/2009/03/07/us/politics/07stem.html >
Article on FDA approval of stem cell trial from the New York Times. January 23, 2009. By Andrew Pollack:
< http://www.nytimes.com/2009/01/23/business/23stem.html >
AAAS Stimulus bill analysis:
< http://www.aaas.org/spp/rd/stim09c.htm >
AAAS briefing on stem cells and legislation:
< http://www.aaas.org/spp/cstc/briefs/stemcells/ >
Library of Congress Appropriations:
< http://thomas.loc.gov/home/approp/app09.html >