Last month, after UW-Madison and Kyoto University researchers announced a new technique that turns skin cells into cells that look and function like embryonic stem cells, the world seemed to breathe a sigh of relief. At last, the end to the nearly decade-long stem cell war was in sight. Or, so it seemed.
Now, as much of the excitement over the new findings begins to die down, scientists and bioethicists stress there is no reason to believe embryonic stem cells are going anywhere anytime soon.
The stem cell frenzy restarted several weeks ago, when the labs of UW-Madison biologist James Thomson and Kyoto University microbiologist Shinya Yamanaka publicized separate reports revealing that the insertion of four genes into skin cells reprograms the cells to become pluripotent. Pluripotency is the trait scientists say allows embryonic stem cells to turn into any of the 220 cell types in the body. While these findings offered a huge step forward in the basic science of stem cell research, researchers stressed more research is needed before they know if the embryonic-like stem cells would prove to hold the potential of embryonic stem cells.
If the cells prove identical and [as] safe [as embryonic stem cells], and this is a big 'if' right now, then potentially the new cells will remove the ethical dilemmas of working with embryonic stem cells,"" said Clive Svendsen, co-director of UW-Madison Stem Cell and Regenerative Medical Center. ""We may one day come to a point where we can [move away] from embryonic stem cell [research], but we're not there now.""
Since 1998, when Thomson first proved he could isolate and maintain embryonic stem cells outside of embryos, politicians, religious groups and scientists have been feuding over the research. While scientists see embryonic stem cells as a potential therapeutic gold mine - the stem cells can theoretically replace any cells in the body destroyed by disease and injury - once the stem cells are removed from an embryo, the embryo dies.
For advocates of stem cell research, embryonic stem cells offer hope for future clinical therapies for heart disease, diabetes, spinal cord injury and other debilitating conditions. For stem cell opponents, embryonic stem cells represent more than just a potential cure for a disease; embryonic stem cells represent the destruction of life.
John Heubscher, Executive Director of the Wisconsin Catholic Conference, said while his organization supports scientific research, the group believes the loss of an embryo represents the loss of human life.
""Embryonic stem cell research destroys embryos, creating a means to the end,"" he said. ""We do not believe humans should be a means to the end.""
In 2001, growing ethical concerns over embryonic stem cell research led President Bush to limit the federal funding for embryonic stem cell research to U.S. researchers who agreed to work only with the stem cell colonies established at the time of the announcement. Of the original 60 stem cell lines Bush said existed at the time of the announcement, scientists estimate only 21 colonies exist today. Though Congress attempted to loosen the federal funding restrictions on stem cell research twice over the past few years, Bush has vetoed both attempts, limiting the embryonic stem cell research scientists could perform.
Scientists were offered new hope when last month's reports suggested researchers had found a way to create embryonic-like stem cells while avoiding the embryo altogether.
""The research is really exciting for basic science and research because the cells look very much like stem cells,"" Svendsen said. ""However, there are still so many questions left to be answered.""
Though scientists were hesitant to speculate on what reprogrammed skin cells can and cannot do, others welcomed the findings as the beginning to the end of embryonic stem cell research. Stem cell opponents have hailed Bush's federal funding restrictions as the driving force behind researchers identifying ways to generate stem cells outside of the embryo.
""There's a lot of politics being introduced into the [stem cell] announcement,"" said Arthur Caplan, a professor of bioethics at the University of
Pennsylvania. ""The President and his supporters have been standing by an alternative to embryonic stem cell research and now they are touting this as their alternative. The proof is in the application, not the announcement. It will quickly become evident that this is not the magic bullet that solves all moral problems [with stem cells].""
In a Dec. 3 op/ed piece in the Washington Post, Thomson addressed the political reaction to his recent announcement. ""Far from vindicating the current U.S. policy of withholding federal funds from many of those working to develop potentially lifesaving embryonic stem cells, recent [findings] described a breakthrough achieved despite political restrictions,"" he said. ""In fact, work by both the U.S. and Japanese teams that reprogrammed skin cells depended entirely on previous embryonic stem cell research.""
""By sifting and winnowing through the genomic data of stem cells, we managed to improve our understanding of what made stem cells perform the way they do. This was dependent upon embryonic stem cell studies,"" Svendsen said. ""If we hadn't gone ahead with embryonic stem cell research with essentially our hands tied behind our back, none of this would've been possible.""
The scientists agree embryonic stem cell research is something that will need to go in the foreseeable future.
""A new way to trick skin cells into acting like embryos changes both everything and nothing at all,"" Thomson said. ""Being able to reprogram skin cells into multipurpose stem cells without harming embryos launches an exciting new line of research. It is important to remember, though we're at square one, uncertain at this early stage whether souped-up skin cells hold the same promise as their embryonic cousins do.""
""We will never understand how the embryonic stem cell-like cells compare to embryonic stem cells without more embryonic stem cell research,"" said Caplan. ""In the immediate future, we can't progress unless we fund embryonic stem cell research.
At UW-Madison, Svendsen said researchers plan to continue exploring all aspects of embryonic stem cells. ""We don't want to stop all of the very successful embryonic stem cell research going on at UW-Madison,"" he said. ""There is lots of cross-campus collaboration and [the new findings] will accelerate research forward. The great ethical research will continue while at the same time we will begin to explore new stem cell research.""
""The bottom line is that you have to be looking through purely political spectacles, or you have to be exhausted to say the stem cell war is over. Part of the celebration is exhaustion,"" said Caplan. ""For those who are exhausted, they are going to have to pull up their shorts and get their debate boxing gloves back on."" Caplan contends the stem cell war is far from over.
