You’ve probably noticed the news reports about medical breakthroughs based on stem cell research; they’re hard to miss. A scientist in Great Britain, for example, announced in July 2013 that he had cultured photoreceptor cells from mouse embryonic stem cells. When these photoreceptor cells were inserted into the eyes of blind adult mice, they formed functioning connections with the correct nerve cells. It will be years before this procedure could be done on humans with cells made from human stem cells, but if it is successful, sight could be restored, for example, to diabetics or to those with macular degeneration. It appears as a sign of a medical messianic age when the blind will see.
Many of the news stories announcing such breakthroughs in stem cell research often note the Catholic Church’s disapproval of this work. This opposition leaves even many of the faithful wondering why the Church seemingly stands in the way of such promising and good work. Neither the research and its promises, nor the Church’s position, are as simple as often portrayed.
Stem Cell Origins
For the sake of simplicity, assume that only two types of cells comprise our bodies. Non-stem cells, or differentiated cells, which are found in tissues or organs, carry out specific vital functions; examples are heart cells, liver cells or nerve cells. Whenever these cells undergo cell division, each daughter cell has the same function as the parent cell.
These cells with their distinct functions arise from stem cells. These cells are undifferentiated in that they have no specific function as do the cells mentioned above. When stem cells divide, one daughter cell remains a stem cell. Depending on the cell’s environment, the other daughter cell becomes a specific differentiated cell, as will all of its daughter cells after cell division. The other cell becomes a differentiated cell and eventually all the cells needed for the organism to live are formed.
In the embryo, stem cells whose daughter cells can possibly become any differentiated cell are found only in the earliest development stages – usually around the first 15 days after conception. If these cells are removed from an embryo and sustained by artificial means (in vitro cultures), they will divide indefinitely. Each cell will produce one stem cell and one undifferentiated cell that can be manipulated to become almost any desired cell.
Stem cells generated from an embryo are called “embryonic stem cells.” The embryos are obtained from in vitro fertilization clinics, where several eggs are harvested fertilization, but not all are used. IVF clinics, however, are not the only resource for obtaining cultures for the generation of stem cells. Stem cells also can be cultivated from blood in the umbilical cord or form bone marrow: The resulting cells are popularly called “adult stem cells.” Adult stem cells may not always be as able to generate the variety of differentiated cells as embryonic stem cells, but in the past few years, scientists have been able to generate a variety of tissues from them.
The Church objects to in vitro fertilization because it considers the result of the union of any egg and sperm that forms a conceptus – no matter the sources – to form a human individual worthy of protection. Furthermore, because the creation of embryonic stem cells necessitates the destruction of any embryo, the Church will not accept this research or the results that flow from it.
The ability of embryonic or adult stem cells grown in vitro continuously to replenish their own supply and to produce differentiated cells make them popular with developmental biologists who use them to study the myriad steps in embryonic and fetal development. These two properties make them popular, too, with scientists who want to apply these properties to solving medical issues.
All of us seek to avoid the disabilities that follow from chronic illnesses or to prolong our lives in good health. These aspirations drive the technological and regenerative medical research based on stem cell research. Can stem cells provide enough healthy cells to replace damaged or absent cells and thereby restore tissue function and health? In theory, yes; in practice, maybe not, or not as easily as the theory promises.
In adult stem cells or cells derived from them are somehow delivered to the tissues needing repair or replacement, the hope is that the host organism will accept them and the damaged tissues will be repaired or missing ones replaced. Experimental evidence using mostly mouse stem cells suggests that this approach could work, but there are severe obstacles between what is done with mice and the creation of therapeutic devices or medicines for humans. The experiments require strict protocols and they are sometimes hard to repeat. Stem cells in host animals occasionally cause cancers or tumors. If these stem cells are adult stem cells, the Church has no moral objection to this research. In fact, the Church has financially supported organizations that promote adult stem cell over embryonic stem cell research.
The biggest hurdle to applying this research to humans is ethical and governed by the Food and Drug Administration. The FDA must determine if the proposed stem cell-based therapy is better than current treatments. In some cases, such as with Parkinson’s Disease, they do not seem to be. The FDA must also weigh the risks of a procedure against its possible gains; so far, risks far outweigh gains.
Issues of justice
As we have seen, the Church does not forbid all research on or application of stem cell research and the Church is not the only agency raising ethical concerns. Regenerative medicine, however, raises other issues. The development, testing, regulatory oversight and marketing of these potential therapies will be expensive. The number of patients who could benefit is small compared to patients with other diseases. Is this the best way to spend what will be a massive investment of public funds? Should monies, for example, be invested in water sanitation programs that could drastically reduce child mortality in low- and middle-income countries – and for a much lower cost than stem cell therapy?
The medical breakthroughs reported so often in the press are years – possibly decades – away from realization. So great are the insights into development and growth that basic stem cell research now gives to scientists, it will continue to enjoy private and public support. While the Church protects life from its very beginning and refuses to countenance embryonic stem cell research, it stands as a partner with those who would further adult stem cell research.
Fr. Thomas P. Gariepy, C.S.C., Ph.D., was ordained on April 20, 1974. Fr. Gariepy is a professor and chair of the Department of Healthcare Administration at Stonehill College in Easton, Mass. His current research focuses on the role Dr. John Fulton’s laboratory played in the development of the frontal lobotomy and the creation mythology that arose around that event. He also has an interest in the history of epidemiology.