Background on iPS: Voices of Science & Policy
Americans for Cures Foundation agrees with leading scientists, policymakers, and advocates that patients and their families deserve every healthcare option that science can provide. We believe that induced pluripotent stem cell technology (iPS) represents an excellent step forward in stem cell science, but we do not believe that iPS should be pursued to the exclusion of other technologies. (See our Statement on iPS.) Clinical trials using human embryonic stem cell (hES) therapy will be considered by the FDA in 2008. But there are major technical barriers to iPS that must be overcome before any therapy can be developed using iPS.
Selected views about iPS from leading researchers in stem cell science are given below.
We agree with Dr. Jamie Thompson, who published the first two studies on iPS with Dr. Shinya Yamanaka, that we must continue work on hES while pursuing iPS. Thompson cautioned that researchers still "must confirm that the reprogrammed human skin cells really are the same as stem cells they get from embryos. And while those studies are under way...it would be premature to abandon research with stem cells taken from human embryos." [1]
Some of the voices arguing for abandoning hES research in favor of iPS alone fail to understand the state and risk of current iPS science, that:
- iPS as currently described carries a risk of cancer,
- There is currently only a viral method of delivering genes to adult cells,
- It is still unknown whether iPS cells will have similar properties as hES, and
- We may be decades away from clinical trials using iPS research and iPS cells.
- Dr. Insoo Hyun, Department of Bioethics at Case Western,
- Dr. Konrad Hochedlinger, Harvard Stem Cell Institute,
- Dr. Rudolf Jaenisch, MIT Department of Biology and Whitehead Institute for Biomedical Research, and
- Dr. Shinya Yamanaka, Kyoto University, Department of Stem Cell Biology
These scientists stated:
".....[I]t would be a serious mistake to conclude that recent developments in iPS cell research (or, for that matter, any other so-called ‘alternative' source of pluripotent stem cells) avert the need for ongoing research on hES cells. There are many important reasons why iPS cell research must be conducted hand in hand with hES cell research. In advancing these reasons we do not mean to imply that hES cell research is not of paramount importance in its own right. There are overwhelming scientific justifications for proceeding with hES cell research, which is precisely why it is important for the public to maintain a realistic perspective on iPS cell research vis-à-vis hES cell research."
We also agree with the views expressed by Susan Solomon, CEO of New York Stem Cell Foundation, and Dr. Zach Hall, former President of the California Institute of Regenerative Medicine, who said:
"The only voices saying that these new discoveries have made the debate over stem cell research moot are the voices that were opposed to (the) research all along." [3]
Additional statements from leading advocates, media, scientists and members of Congress are given below.
Michael J. Fox, actor, activist and founder, Michael J. Fox Foundation for Parkinson's Research, 07/2007 [4]
"I am pro-research, pro-science and support all forms of stem cell research," said actor Michael J. Fox, a leading advocate for embryonic stem cell research, in a letter to Congress this year. "Every scientist I've spoken to (and a lot more I haven't) believes that embryonic stem cells may hold the key to better treatments and cures-not only for Parkinson's disease but for cancer, diabetes, spinal cord injuries, heart disease, Alzheimer's and countless other illnesses that cut short or diminish millions of lives every year."
Editorial, San Jose Mercury News, 11/27/2007
"...Opponents of embryonic stem cell research, including President Bush, are already arguing that the skin cell advance [IPS] should end the use of stem cells derived from human embryos. That would be shortsighted.....Scientists are years away from knowing if human skin cells will actually work as a substitute.
President Bush's stem cell strategy is to deny federal funding for research because it destroys human embryos. But his moral objection doesn't apply to hundreds of thousands of human embryos discarded every year in the name of in vitro fertilization....the President and others [have been] playing politics with stem cell research..."
Dr. Irving Weissman, Director of Institute for Cancer/Stem Cell Biology and Medicine, Stanford University, USA Today, 11/25/2007 [5]
"Because we cannot decide in advance which method will get us there first, and because the lives of these patients must be paramount, we should not gamble their lives on one...method."
Dr. Kevin Eggan, Harvard University and Scientific Director, New York Stem Cell Foundation, Wall Street Journal, January 8, 2008; in a press release from New York Stem Cell Foundation, www.nyscf.org, 11/20/2007 [6], [7]
"They [IPS cells] are genetically changed in a way that should make us worried about using them in animals or people, or to model diseases," said Harvard University stem-cell biologist Kevin Eggan....."Until the reprogrammed cells can be made safe and stable enough for clinical experiments, he added, Human embryonic stem cells will be better, even if they are more complicated politically."
"....the research uses known cancer-causing genes to reprogram cells and return them to an embryonic-like state........The retroviruses used to introduce these additional genes often turn on cancer genes that are already present. It remains to be determined whether reprogramming can be achieved without using cancer-causing genes. We must also be certain that the resulting pluripotent stem cells are entirely equivalent to embryonic stem cells."
Dr. Story Landis, NIH Stem Cell Task Force, Los Angeles Times, 11/21/2007
" ...the head of the National Institutes of Health stem cell task force said it would be a mistake for scientists to back away from research on embryonic cells. Dr. Story Landis said the breakthrough with mature cells was possible in part because of earlier work with embryonic cells. ‘This does not obviate the need for human embryonic stem cell research,' Landis said. To be able to compare results from the two types of research ‘is critical,' she added."
Dr. Rudolph Jaenisch, Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, Washington Post, 12/7/2007 [8]
"All the progress in this field was only possible because we had embryonic stem cells to work with first, Jaenisch said. We need to make more [h]ES cells and really define which are going to be the best ones for different applications."
Dr. Evan Snyder, director of the stem cell research center at the Burnham Institute in California, Chicago Tribune, 11/21/2007
"Every time we get a headline like this, some policymakers say, ‘OK, now we can stop funding embryonic research, and you guys can get jobs at McDonald's,'" Snyder said. "But this means there's a whole new area of research that Congress needs to fund, and you've got to compare all the cells head to head."
Dr. Bill Brinkley, Professor of Cell and Molecular Biology and Dean of the Graduate School of Houston's Baylor College of Medicine; Huffington Post, 11/21/2007 [9]
"Although we are excited by these new discoveries, and remain even more optimistic about future developments of techniques that may utilize human stem cells for regenerative medicine, we believe that to disregard any procedure that currently holds promise is short-sighted and scientifically risky. A clear example is the Oregon team's development of the procedure that has worked effectively to produce a wide array of embryonic cells in non-human primates. To choose to focus on only one avenue of research or type of cell source, would -- at this stage of regenerative medical research -- be irresponsible, unreasonable, and premature........Promising and successful research exploring human stem cells should be supplemented with--not supplanted by -- new and potentially exciting approaches, with all forms of research moving forward along multiple independent paths. Scientific research -- whether it be in cancer, diabetes, tissue regeneration or other areas -- should proceed freely and openly along all viable lines of investigation until sufficient progress has been made to be successfully applied to the treatment and alleviation of diseases and human suffering."
Dr. Robert Lanza, CEO, Advanced Cell Technology, MSNBC.com, 11/20/07 [10]
".....First of all, the function of the reprogrammed cells will have to be compared closely with the function of actual embryonic stem cells. ‘I'd be surprised if these cells do all the same tricks as stem cells derived from embryos,' Lanza told msnbc.com.
Also, in both experiments, the four-gene recipe was added to the skin cells using a virus as the delivery package. ‘The FDA [Food and Drug Administration] would never allow us to use these virus-modified cells in patients,' Lanza said."
Senator Arlen Specter, (R-PA) NY Times, 11/21/07 [11]
"I really don't think anybody ought to take credit in light of the six-year delay we've had....My own view is that science ought to be unfettered and that every possible alternative ought to be explored....if we can find something which is certifiably equivalent to embryonic stem cells, fine. But we are not there yet."
Representative Diana DeGette, (D-Colo), Washington Post, 11/21/2007 [12]
"I don't think this changes the debate," said [DeGette], a key participant in the House debate. "We still need to encourage all types of research, and we need to put ethical oversight in place."
Senator Edward M. Kennedy, (D-Mass), Washington Post, 11/21/2007 [13]
"Kennedy hailed the new reports as ‘extraordinary scientific breakthroughs,'" but said embryonic stem cell research must continue. "Instead of aiding that fight, the Bush administration is hampering it through needless restrictions on stem cell research and by denying NIH the funds it needs to capitalize on new advances."
