Stem cell controversy continues

Despite lifted federal funding ban, new research methods and FDA approvals, social and ethical questions remain

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Since 1998, when privately funded research led to their breakthrough discovery, human embryonic stem cells (hESCs) have been a hotly debated nexus of conflicting scientific, political and religious views. The debate centers on the moral implications of research involving the creation, usage and destruction of human embryonic stem cells, with some opponents concerned about the destruction of human embryos and others arguing that the practice introduces a slippery slope toward reproductive cloning that fundamentally degrades human life. Conversely, many medical researchers argue that hESC research demonstrates the potential to dramatically alter approaches to understanding the origins and treatment of disease, and that excess embryos created for in vitro fertilization should be able to be donated with consent and used for this research.

A brief legislative history might be useful here: On Aug. 9, 2001, President George Bush announced that for the first time, federal funds would be made available for hESC research on currently existing stem cell lines. However, the Bush Administration chose not to permit government funding for research on hESC cell lines that were not currently in existence, meaning federal funding was limited to research in which "the life-and-death decision has already been made." While the Bush Administration's constraints differed from President Bill Clinton's administration guidelines, which did not distinguish between currently existing and not-yet-existing hESC, both administrations' initiatives agreed that the U.S. government should not fund hESC research that directly destroys embryos.

During his two terms in office, President Bush vetoed a number of bills concerning the loosening of limitations on federally funded embryonic stem cell research that had been passed by Congress, including the Stem Cell Research Enhancement Acts of July 2006 and April 2007. President Bush's vetoes pleased many religious conservatives who have moral objections to the use of cells derived from human embryos and believe that embryonic stem cell research violates the sanctity of human life and is tantamount to murder. The fundamental assertion of those who oppose embryonic stem cell research is the belief that human life is inviolable, coupled with the belief that human life begins the moment a sperm cell fertilizes an egg cell.

Others in the medical community, however, believed these decisions restrained promising research into defeating a wide range of diseases, including Parkinson's and Alzheimer's. It is also important to note that while neither Congress nor any administration has ever prohibited private funding of embryonic research, and that public and private funding of adult and cord blood stem cell research has gone unrestricted, President Bush's ban on federal funding for embryonic stem cell research caused a number of academic and scientific institutions to shy away from the field out of fear that subsidy and grant monies might be threatened by association.

On March 9, President Barack Obama signed an executive order lifting the Bush Administration's restrictions on federally financed hESC research. Not coincidentally, the order was ideally timed for researchers to take advantage of money in President Obama's economic recovery package. This decision also provides Congress with an opportunity to overturn the 13-year-old Dickey-Wicker Amendment, which specifically bans the use of tax dollars to create human embryos, or for research in which embryos are destroyed, discarded or knowingly subjected to risk of injury.
Many believe the move signals a broader declaration concerning the current administration's position regarding the pursuit of scientific advances versus rigidly held political ideology, with President Obama pledging that his administration will "make scientific decisions based on facts, not ideology."

Despite the shifts in the political wind and promising new initiatives, the controversy surrounding embryonic stem cell research still promises to persist because of the number of people who oppose them on moral grounds.

In December 2008, the Vatican issued its most authoritative and sweeping document on bioethical issues in more than 20 years, taking into account recent medical developments in the fields of in vitro fertilization, human cloning, genetic testing on embryos and stem cell research. The 32-page document, titled "Dignitas Personae," or "The Dignity of the Person," was issued by the Congregation for the Doctrine of the Faith, the Vatican's doctrinal officer, and carried the approval and authority of Pope Benedict XVI. While the Vatican document reiterates the Church's opposition to research performed on stem cells derived from embryos, somewhat surprisingly, it does not oppose research on stem cells derived from adults, blood from umbilical cords or fetuses "who have died of natural causes."

The document also does little to clarify the Church's position on significant new stem cell research techniques, including Induced Pluripotent Stem (iPS) cells in which stem cells are created from skin or other donor tissue, and Human Parthenogenetic Stem Cells (hpSC cells), created through a procedure whereby a pluripotent stem cell line is created from an unfertilized human egg without destroying a fertilized embryo. Using these methods, scientists are able to generate functional pluripotent stem cells (that is, stem cells that have the ability to turn into any type of cell or tissue) without the use of fertilized human embryos, thereby solving the ethical dilemmas surrounding stem cell research.

While the Vatican bioethics proclamation comes out squarely against in vitro fertilization, human cloning and embryonic stem cell research, stem cell lines created using iPS and hpSC cells do not involve fertilized embryos and may find some support within the clergy for a stem cell research alternative that offers a solution to the need for a truly pluripotent stem cell.

Immune rejection is one of the greatest impediments in the application of human cell therapies today. One cause of the current excitement surrounding iPS cells is the hope that they will provide access to a patient's own cells for therapy, thus avoiding immune rejection. This technique, however, requires genetic manipulation and the introduction into the cell of viruses that are associated with cancer. The mechanism of how iPS technology works is still unknown, and scientists are working to eliminate the need for cancer-causing agents. If iPS technology can be proven to be safe to the regulatory agencies—a very large hurdle at this time—it holds great promise to provide specialized or "custom medicine" for the patients who can afford it and have the time to wait the many months that it will take to harvest personalized cells. It may, however, not be as effective for autoimmune diseases like diabetes, where the patient's immune system already attacks its own cells. For these diseases, it may be far better to use cells from an alternate source that can address immune rejection in a different way.

Parthenogenetic hpSC cells represent a different approach to the problem of immune rejection. They are designed to provide cells that are immune-matched to millions of patients—mitigating the problem of immune rejection in a similar manner to that used by physicians in whole organ transplantation. Unlike iPS cells, parthenogenetic hpSC cells are not intended to provide an identical immune match, except for the donor, but to provide closely matched cells that can minimize or eliminate the use of immunosuppressant drugs and be immediately available for use by a wide range of patients in a manner analogous to the use of blood banks today. hpSC cells could thus be uniquely valuable for such things as acute liver failure, where there is no time to wait for a patient's own cells to grow, and for all those situations where either cost or the need for immediate action precludes customized medicine. Because hpSC cells do not involve any foreign vectors or genetic manipulation, they may also be available to patients sooner than customized cells from iPS.

In mid-January, the U.S. Food and Drug Administration (FDA) cleared the way for the first human trials of human embryonic stem cell research, authorizing Geron Corp. to test whether cells are safe for use in spinal injury patients. The FDA's decision comes as encouraging news for the medical and scientific communities, as it marks a significant acknowledgement that the organization is growing more comfortable with stem cell use.

Science, politics and religion can make difficult traveling companions. While many doctors, physicians, scientists and researchers applaud the recent FDA decision and would wholeheartedly embrace the new administration's intention to lift the ban on embryonic stem cell research, these events tell just part of the story. Medical, scientific, societal and ethical complications continue to swirl around this issue. While shifting political winds promise to have an important impact on the future of stem cell research, even were federal funding bans to be lifted tomorrow, the controversy surrounding stem cell use will not disappear overnight.
Kenneth C. Aldrich is chairman, CEO and co-founder of International Stem Cell Corp., which created the first human Parthenogenetic cell lines, and is an active member of Tech Coast Angels. Aldrich has been active in venture capital investing and private equity since 1975, providing early-stage funding and management for a variety of biomedical and technology start-ups, including WaveTec Vision Systems, an ophthalmic device company, Neurion Pharmaceuticals Inc., a drug discovery and evaluation company, and Orfid Corp., a developer of organic transistors. He is also a director of Green Dot Corp., the world's largest issuer of pre-paid debit cards. Aldrich holds degrees with honors from both Harvard University and Harvard Law School.

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