Adult Stem Cells Versus Human Embryonic Stem Cells

August 9, 2001 President Bush made a compromise decision regarding the use of embryonic stem cell lines.

"I have concluded that we should allow federal funds to be used for research on these existing stem cell lines, where the life and death decision has already been made." George W. Bush ¹

At that time, there were about 69 stem cell lines in existing. The president also allocated some federal funding to further research on these pre-existing stem cell lines. No federal funds are to be allocated to stem cell lines created after August 9, 2001. However, despite lack of federal funding, private companies have continued creating new embryonic stem cell lines as well as cloned-embryo lines.

George W. Bush's declaration on stem cell research follows in the legacy of president Ronald Reagan's "Personhood Proclamation" issued on the fourteenth of January, 1988.

"That right to life belongs equally to babies in the womb, babies born handicapped, and the elderly or infirm...I, Ronald Reagan, President of the United States...do hereby proclaim and declare the unalienable personhood of every American, from the moment of conception until natural death." ²

The logic seems to be that with the existing stem cell lines, the "life and death" decisions had already been made and therefore it didn't really make sense to prohibit research on the existing stem cell lines. A question we can ask now is, what about those embryos that have been coached to develop without a sperm? In this case, there is no conception, but the egg still starts to develop. Is it morally wrong to destroy these embryos? Do embryos have souls?

Why not just use adult stem cells?

Many pro-lifers have asked this same question. The Christian Medical Association sent a letter to Congress in 2004 encouraging the legislature and administration to lend support to adult stem cell research, as opposed to embryonic stem cell research. Adult stem cell treatments have already been tried in numerous cases. According to pro-life advocate Dr. David Stevens, one Parkinson's patient's condition improved greatly after his own neural cells were used to treat him. He also claims that bone marrow cells have been used to repair damaged heart muscle in German patients. "The bottom line, Stevens asserts, is that Christian doctors want the quickest, most ethical, an most economical way to find real cures for real patients. He says adult stem cells are giving results now and providing cost-effective treatments, while embryonic stem cells are 'prohibitively expensive' and, at best, any possible help from them is probably 10-15 years away."³

Embryonic stem cells vs. Adult stem cells

Embryonic stem cells:

• Research started in 1988

• Pluripotent

• Can generate all cell types

• Easily grown in culture

• Possibility of organ rejection

• Derived from human embryos

• Shed light on human development process

• Potential for cell-based therapies

Adult stem cells:

• Research started in 1960s

• Multipotent

• Can generate specific cell types

• Rare in tissue, not easily grown in culture

• Patient's own cells used to avoid rejection

• Shed light on reparation and regeneration process

• Potential for cell-based therapy

One of the basic advantages of embryonic stem cells is that they can be grown more easily in culture and proliferate more rapidly and for longer periods of time than adult stem cells. Large numbers of cells need to be produced for any cell-based therapies as well as for the purposes of effective drug testing, and currently scientists are not able to produce large numbers of identical adult stem cells in a short amount of time. The other main advantage is that embryonic stem cells are pluripotent and have the ability to form any kind of cell the body needs. To compare them to adult stem cells, embryonic stem cells have unlimited plasticity. They do not need to transdifferentiate because it is natural from them to become any kind of cell. There is no specific set of cells that embryonic stem cells naturally differentiate into.

With embryonic stem cells, it is a matter of figuring out the right set of signals to trigger differentiation into a certain kind of cell. With adult stem cells, it is a matter of figuring what can be manipulated to make the cells become a type of cell they would not normally become. Embryonic stem cells can be observed to derive the set of signals necessary for natural development into any kind of cell, but with adult stem cells one must use something like a trial and error approach to try to manipulate stem cells to give rise to a completely different kind of cell. There is research being conducted to try to see what signals trigger transdiferrentiation without the help of a scientist and a cell culture, but it is debated whether this happens at all in nature and if it happens enough to derive the set of signals that cause it to happen.

Further Reading by Heather Carreiro:

What are Stem Cells?

The Bush Administration and Stem Cell Research

End of Life: What Does it Mean to be Brain Dead?

Stem Cell Research: A Christian Perspective

Sources:

1) Bush, George W. Public Announcement August 9, 2001. National Right to Life.http;//www.nrlc.org/killingembryos/textpresidentbush.htm

2) Reagan, Ronald. "Personhood Proclamation." Speech: 14 Jan 1988. National Right to Life. http://www.nrlc.ReaganProclamation.html

3) Parker, Jenny & Matt Rettig. "Christian Doctors Call for Support of Adult Stem Cell Study." Agape Press. August 10, 2004. http://www.crosswalk.com/news/1278442.html