Tuesday, March 29, 2011

Ethical Problems with Adult Stem Cell Research?

Using a rather unusual approach to address the inherent ethical issues surrounding destructive human embryonic stem cell research (hESCR), Dr. Insoo Hyun, director of the Case Western Reserve Stem Cell Ethics Center, seeks to divert attention from those ethical difficulties by pointing to what he supposes is the ethical baggage carried by adult and induced pluripotent stem cell research.

First, the background: hESCR is controversial because of the inherent ethical problem that it requires the destruction of human life – at its embryonic stage – to provide a possible benefit to others. Inherent to hESCR is the fact that it commodifies and then destroys human life, making such destruction the means to another’s potentially beneficial ends.

So, according to Prof. Hyun, what are the ethical controversies associated with research using induced pluripotent stem cells (iPSCs) and adult stem cells?

Well, one day in the future someone may discover a way to direct iPSCs to become functioning egg and sperm cells. These could, for example, be used to help someone who has lost their fertility because of chemotherapy treatment for cancer, Hyun posits. But he further posits that “It may also offer hope for homosexual couples who may want to produce biologically related children together (men would be able to produce both sperm and eggs; women could not produce sperm cells because they lack the Y chromosome)”.

He comments: “Undoubtedly there will be individuals who would support the former but strongly oppose the latter”.

That is undoubtedly true.  The adoption of children by homosexual couples is already a contentious issue. Undoubtedly it would be more so if a homosexual male used induced pluripotent stem cells to become both the genetic mother and father of a child. And no doubt this would also be ethically contentious if a heterosexual male attempted to do the same. But none of the ethical issues that would arise from such a circumstance has anything inherent to do with the ethics of research using iPSCs.

Remember, one of the two researchers credited with discovering iPSCs, Shinya Yamanaka, did so precisely because he was motivated to overcome the ethical problems inherent in hESCR. Recalling looking at a human embryo through a microscope several years earlier, Yamanaka said: ''When I saw the embryo, I suddenly realized there was such a small difference between it and my daughters…I thought, we can't keep destroying embryos for our research. There must be another way'' (“Risk Taking in His Genes;” The New York Times, 12/11/07).

There was and Yamanaka succeeded in discovering it. There are no inherent ethical problems associated with research using iPSCs. That someone, someday, may use them for ethically dubious purposes, such as the one Prof. Hyun posits, does not change this fact. Is the use of morphine and other powerful pain-killers in providing hospice care inherently unethical because some want to push it into the ethically questionable area of assisted suicide and euthanasia?

And what are the ethical problems associated with adult stem cells? Prof. Hyun asserts that adult stem cells have in effect become enablers of “stem cell tourism - i.e. desperate patients traveling across borders for fraudulent therapies.”

Well, the same holds true for hESCs. India’s Geeta Shroff has lured hundreds of patients from around the world to her clinic claiming—without a shred of evidence – to use hESCs to help them.

More to the point, the peddling of snake oil is as old as the practice of medicine itself. Just because quacks peddle fake treatments and medicines to make a buck does not make the fields of medicine and pharmacology, and those who honorably serve in those fields, inherently unethical.

Another ethical problem Prof. Hyun asserts regarding adult stem cell research is that part of it involves using stem cells obtained from abortive fetuses, which many consider unethical.

This statement is at best misleading. It’s no doubt true that many find using research tissue from abortive fetuses to be unethical. But in terms of the embryonic stem cell debate, Prof. Hyun seems to be the only one raising the issue of stem cells derived from abortive fetuses (that public policy debate took place over two decades ago).

While true that both fetal stem cells and adult stem cells are partly differentiated and tissue specific cells, in terms of the public policy debate “adult stem cell research” has always referred to research using cells obtained after birth, whether it be from the patient him/herself or other sources such as umbilical cord blood, solid cord, placenta, amniotic fluid or adipose (fat) tissue. All sides in the public policy debate over hESCR agree that research using cells from these sources is ethically non-contentious. That some are doing research on tissue specific stem cells derived from abortive fetuses does not change this fact.

Furthermore, in terms of actually providing therapeutic benefits to patients, not one of the 73 diseases or conditions that the Do No Harm coalition lists on its website, using peer-reviewed literature, were treated with fetal stem cells. All of the benefits came from using adult stem cells from the patient him/herself or from the other sources listed above, or from donors. As far as Do No Harm knows, no therapeutic benefits to patients have been shown using stem cells from abortive fetuses. For Prof. Hyun to introduce stem cells derived from abortive fetuses into the public policy debate on hESCR is a non sequitor at best and a rather transparent, clumsy attempt to discredit adult stem cell research on ethical grounds at worst.

Especially because fetal tissue has shown the opposite of therapeutic benefits to patients. A May, 1996, Neurology article disclosed a patient's death caused by an experiment in China in which fetal nerve cells and embryo cells were transplanted into a human Parkinson's patient. After briefly improving, the patient died unexpectedly. His autopsy showed not only that the tissue graft had failed to generate new nerve cells to treat his disease as had been hoped; even worse the man's death was caused by the unexpected growth of bone, skin, and hair in his brain, material authors theorized resulted from the transformation of undifferentiated stem cells into non-neural, and therefore deadly, tissues.

In a clinical trial reported in March, 2001 in The New England Journal of Medicine, researchers using fetal tissue to treat Parkinson’s patients reported that 15% of those treated saw their condition worsen, as they developed uncontrollable, disabling movements. Dr. Paul Greene, a member of the team conducting the trial called this development “absolutely devastating” to the patients and called for an end to fetal tissue transplants.

In 2009, scientists published evidence showing that a young Israeli boy’s brain and spinal tumors were derived from injections of fetal stem cells. No one confused them with adult stem cells, when they identified the source of the cells, when fetal stem cell researchers took pains to claim their fetal stem cells were purified, unlike those injected into the Israeli boy, or when the FDA put a fetal stem cell company’s clinical trial on hold.

Prof. Hyun’s whole effort to divert attention from the very real, inherent ethical problems with hESC by trying to cast contrived ethical shadows over adult and induced pluripotent stem cell research is misinforming and misleading.

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