Stanford stem cell experts reflect on five-year anniversary of decision limiting research funding

STANFORD, Calif. - Time is a precious commodity to stem cell expert Irving Weissman, MD, and as the director of the Stanford Institute for Stem Cell Biology and Regenerative Medicine, he is disappointed that he's had to spend big chunks of the past five years focusing on creating duplicate facilities for his researchers rather than working to unlock the secrets of stem cells.

Weissman said this diversion of time and resources ultimately delays progress in treating human disease. "We have to carefully separate private funding for research using non-approved stem cell lines. That includes separating the materials, technologies and research facilities funded by the U.S. government, which cannot be used for studying privately funded lines," he said .

The genesis of the frustrations for Weissman and other U.S. stem cell researchers is an executive order signed by President George W. Bush on Aug. 9, 2001, limiting federal funding for embryonic stem cell research to only those studies using stem cells that were derived prior to his announcement.

How the ban has affected research (2:44)

Embryonic stem cells are pluripotent, meaning they can become all, or nearly all, cell types in the adult body. Such flexibility means that scientists could one day coax stem cells to become neurons in patients with injured brains or insulin-secreting cells for diabetics. Bush opposes the research on moral grounds because the roughly 6-day-old embryos are destroyed in order to harvest the stem cells.

Although the president in 2001 claimed there were 64 embryonic stem cell lines in existence, researchers now say there are fewer than 20 such lines - some of which may not be clinically useful. To create or work with new embryonic stem cell lines, institutions must create and equip separate facilities that weren't built with federal funds. Additionally, scientists must obtain private funding for the research itself.

As the five-year anniversary of the president's decision approaches, Weissman and other stem cell experts at the Stanford University School of Medicine reflected on what has transpired since 2001 and their hopes for the next five years.

What has the last five years shown us? (3:18)

How would your work today be different if the limitations on embryonic stem cell funding had not been imposed in 2001?

David Magnus, PhD, director of the Stanford Center for Biomedical Ethics: We would have had national standards and guidelines much sooner, and we would not have been distracted by debates over the status of embryos and embryo-like constructs. We would have had to work much faster to figure out how to handle informed consent and other practical ethical challenges.

Gary Steinberg, MD, professor of n eurosurgery and neurosciences, who is investigating the use of stem cells to treat brain damage: We would be moving faster in terms of understanding the unique benefits of various embryonic stem cells for therapeutic applications such as stroke, Parkinson's disease, brain and spinal cord injury, ALS, brain tumors, epilepsy and Alzheimer's disease. My lab is focused particularly on using stem cell transplantation to restore function after stroke.

Christopher Scott, PhD, director of the Stanford Program on Stem Cells in Society: Our program - which focuses on the ethical, legal, social and business issues of stem cell research and medicine - is the only one of its kind in the country, but it has been slow going without proper funding. For example, in the mid-1990s there was money set aside to fund ethical and social issues of the Human Genome Project. Without federal support, fundraising from private donors has been difficult. We had hoped the California Institute for Regenerative Medicine would provide support for our programs but that effort has been locked up in lawsuits.

Despite the federal ban, what's the most significant thing we have learned about the promise of embryonic stem cell research in the past five years?

Weissman: Julie Baker at Stanford has produced two new human embryonic stem lines and more have been developed at other locations in the United States. Researchers in Japan have made progress in finding the genes that allow body cells to reprogram to the embryonic stage of development. While research in embryonic stem cells has been slow, researchers at Stanford and elsewhere have made great progress in research with adult stem cells and in the new area of cancer stem cells.

Stefan Heller, PhD, associate professor of otolaryngology, who is investigating the use of stem cells to repair hearing damage: The past five years were key in redefining possible new approaches to find a cure for hearing loss, and stem cells played a big role in this process. We experienced the advent of stem cell-based regenerative approaches for the inner ear.

Scott: I've learned three things. First, that politics can have profound negative effects on science. That fact was made crystal clear when stem cell researcher Roger Pedersen left UCSF for England while I was there as assistant vice chancellor. Second, you can't stop science from moving ahead. States, institutions and individual laboratories have been remarkably resilient in finding money - sometimes in significant amounts - to fund research. Third, that other countries where the research is permitted are stepping into the breach. Their discoveries are encouraging.

Philip Pizzo, MD, dean of the Stanford School of Medicine and a member of the Independent Citizens' Oversight Committee for the state's stem cell institute: One of the important transitions in the past five years has been the increasing proportion of Americans who have become supportive of embryonic stem cell research. Their voice reflects a gap between the Bush administration's tenacious fixation on religious ideology and America's common-sense perspective about the value of medical research in improving the lives of adults and children. This is coupled with an increasing number of American citizens who have stepped forward to support embryonic stem cell research through philanthropy along with a rising choir of bipartisan support from the Congress. In addition, a number of states have demonstrated their support for stem cell research through either state-funded research programs or legislative activities.

What are the most important areas of research going forward? (3:31)

Looking ahead, what's the most important thing to learn in the next five years?

Weissman: We will continue pushing forward on four stem cell fronts: 1) Learning how to regenerate diseased tissues using adult tissue stem cells; 2) Finding new and useful embryonic stem cell lines and the tissue stem cells they make, such as the heart and lung; 3) Finding safe, ethical ways of making stem cell lines from patients with genetic diseases that help us understand and treat those diseases; 4) Finding new therapies based on our cancer stem cell research and using our discoveries to treat Stanford cancer patients.

Magnus: We need to learn how to handle issues that will arise in clinical trials involving human embryonic stem cells. For example, should recipients know how the cells were derived? What sort of oversight mechanisms should be in place?

Heller: We still do not know the true potential of stem cells for regenerative approaches to the inner ear. The most significant findings in upcoming years will be the discovery of the mechanisms that let us control stem cell differentiation into specific cell types. We will transfer protocols from mouse cells to human embryonic stem cells.

Steinberg: We need to learn w hether embryonic-derived stem cells can repair damaged brain and spinal cord tissue and restore neurologic function after various types of injury without causing tumors. Also, whether embryonic stem cells from patients with various diseases can be used to study the underlying mechanisms causing these diseases. Finally, in phase-1 and phase-2 clinical studies, can human stem cell transplantation safely improve neurologic function in select, debilitating neurologic diseases?

Pizzo: We need a more enlightened policy on embryonic stem cell research that is consonant with the American people and that speaks for a future that engages science and avoids rhetoric and ideology.

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