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Researchers who study human embryonic stem (hES) cells are working to devise cures for some of our most intractable diseases. On this 10th anniversary of the discovery that hES cells could be grown in culture, top U.S. stem cell scientists reflected on the promises and challenges of research with these extraordinary cells. These conversations reveal progress in areas unanticipated a decade ago, and validate the researchers’ dreams that patients are likely to experience real benefit. They also lead to the unmistakable conclusion that in order to harvest the full rewards of the scientific successes thus far, the Federal government must resume its traditional role of full partner by lifting the restrictions imposed on Federal funding.
The phase 1 goals of hES cell research have been achieved. hES cells have become an important vehicle for learning about tissue development and discovering the genes involved in self-renewal. And researchers have learned how to coax hES cells to form many kinds of cells in the human body, including heart cells, motor neurons, and dopamine-producing brain cells.

With the knowledge gained in the past decade, stem cell research is more promising than ever. Researchers at U.S. universities, medical centers, and in industry are moving toward safer and speedier drug development and devising hES cell-based treatments. These efforts may move the study of disease from people to Petri dishes. They are growing the cell types that are damaged or die in various forms of disease, such as Lou Gehrig’s disease (amyotrophic lateral sclerosis) and using them for drug discovery. They are growing human heart cells and liver cells and testing whether new drugs are safe against these sensitive tissues-before the drugs ever enter testing in patients. Improvements in predicting failures before patient testing could save $100 million in development costs per drug, according to a report by the U.S. Food and Drug Administration.

Access to hES cells is crucial to continued progress. These pluripotent cells that can self-renew are an unmatched research tool for understanding the body and what goes wrong in disease. Researchers refer to them as “the gold standard” because these are the cells with the greatest potential for making any cell type in the body. Study of these cells has led to the development of other potential sources of self-renewing cells, such as the reprogramming of adult skin cells to make induced pluripotent stem (iPS) cells. The ability to make iPS cells demonstrates the power of hES cell research to transform science and create new medical opportunities. Researchers will continue to test iPS cells against hES cells to determine their potential and limitations. Continued research on hES cells may reveal other ways to accomplish regenerative medicine, but the paradigm-shifting discoveries come when scientists have access to all avenues of exploration.

Federal restrictions are hindering collaborations and slowing research. Biotech firms that are eager to share cell lines with researchers to speed discoveries, are restricted from doing so if those researcher are receiving Federal funding for that research. Seldom does the Federal government decline to fully support research that has such potential to solve major public health problems. Stem cell research is one of the most exciting fields of study for young researchers, yet many are hesitant to enter a field with an uncertain future and funding restrictions. In addition, the restrictions fly in the face of the diversity requirements established by the Federal government for clinical research. The federally approved lines do not represent the diversity in our society, which is a critical part of ensuring that new medicines work for everyone.

 

Biotech firms are betting on the future of stem cell research and pharmaceutical companies have begun to invest as well. They see an electrifying future in using hES cells as tools for testing and developing new drugs. Some firms are moving swiftly toward the clinic to test cell therapies in humans. For example, Geron Corporation and scientists from University of California, Irvine, are exploring the challenges of implanting hESC-derived glial cells in patients to repair acute spinal cord injuries. They are close to clinical testing. Researchers need the time and support to address safety concerns for using hESC-derived therapies in humans. To explore what happens to cells once they are transplanted, determine how the body reacts, reveal any health risks, and see how the therapy interacts with important medications.

Based on hES cell research, scientists see great promise in efforts to improve therapies for diabetes, Parkinson’s disease, macular degeneration, cancer, spinal cord injuries, and heart disease. The time for removal of restrictions, expanded support, and implementation of relevant oversight guidelines is now.