Research on human embryonic stem cells (ES cells) holds the potential for a new era of "regenerative medicine" in which damaged cells could be replaced with healthy ones, treating currently incurable conditions such as blood cancers, spinal cord injury, immune deficiencies and Parkinson's disease. Studying ES cell lines created from patients with specific diseases will also give insight into diseases on a cellular level. ES cells can even be cultured for drug screening to expedite pharmaceutical discoveries.
Before President Barack Obama's executive order on March 9, 2009, federal money for human ES cell research could only be spent on ES cell lines created before August 9, 2001, many of which had limited usability. United States researchers were forced to rely heavily on private or state funding, and many created two parallel, strictly separate labs—one to work with the federally sanctioned lines and the other for the "NP" or non-presidential lines—with equipment, even pens, meticulously labeled. Progress was often slow and difficult.
The laboratory of George Daley, MD, PhD, associate director of the Stem Cell research program at Children's Hospital Boston, is one of the few in the world to simultaneously pursue a variety of strategies for producing ES cells, or cells that look and act similarly. One approach uses genetic reprogramming of mature (usually skin) cells to produce induced pluripotent stem cells (iPS); another allows production of ES cells from unfertilized human eggs. However, both of these approaches pose a risk of cancer or abnormal tissue growth and are not yet viable for clinical application. ES cells derived from embryos, on the other hand, are genetically "pristine" and could provide a faster, safer route to the clinic. Their properties are also better known—indeed, the ability to generate iPS and egg-only stem cells is possible because of lessons learned from ES cells—and they remain the gold standard against which stem-like cells are measured.
The new policy will make hundreds of newer ES cell lines eligible for federal funding, which is certain to lead to faster progress and more breakthroughs. It is also expected to create opportunities for junior scientists, who previously may have stayed away from stem cell research because of limited funding, and will allow public and private research funds to go further by eliminating the need to purchase duplicate equipment and supplies.
As for the fine print, President Obama's order gave the NIH 120 days to set out specific guidelines for human ES cell research, and Congress has been called on to pass legislation governing the research. "We're all waiting to see what the details of the policy will be," says Daley. "If it limits funding to lines exclusively from frozen embryos left over at in vitro fertilization clinics, that would be a very restricted course and would exclude some very important lines."
Editor's update: The NIH will accept public comments on the draft guidelines until May 26, 2009.