Stem cell research, though potentially life-saving, is a controversial ethical issue in the United States, as some people consider it murder, depending on their definition of embryos.

The biology of stem cell research was discussed during the weekend at the 13th annual Growth Factor and Signal Transduction Conference at the Scheman Building.

“Most of the experimental work is being done with other species,” said Marit Nilsen-Hamilton, professor of biochemistry, biophysics and molecular biology. “It resolves the ethical dilemmas, and it also helps us to understand the stem cells.”

Stem cells are able to transform into many different types of cells, such as bone, muscle and cartilage cells. Because of this ability, stem cells have potential to treat diseases where different cells in the body are damaged or lost and need to be replaced.

There are four different types of stem cells: Embryonic, fetal, umbilical and adult stem cells. Embryonic cells are taken from human embryos, fetal cells are taken from aborted fetal tissue, umbilical cells are taken from umbilical cords, and adult cells are taken from adult tissue.

Research within the first two categories is the source of most ethical debate, because the embryo or fetus is killed in the process of collecting stem cells.

“If there are good reasons not to do this research, then the fact that we’re prohibited from doing it shouldn’t bother us,” said Clark Wolf, associate professor of philosophy and director of bioethics. “But if this is fundamental research that promises tremendous benefits and isn’t morally wrong, then I think it should be disturbing that this research is being done elsewhere other than in the U.S.”

Because of ethical concerns, there is currently no federal funding in the United States for research on new embryonic stem cell lines. Research on the stem cell lines that existed before President Bush’s ban in 2001, however, is federally funded.

“President Bush put in place a policy limiting the private stem cell research that can be done using embryos,” Wolf said. “As a result, all stem cell research that’s done at any institution needs to be done on the few stem cell lines, many of which are managed by a very few universities and organizations.”

Ethical debate surrounding stem cell research is focused on the definition of embryos. If embryos are considered people, then using them for research would be the same as murder.

“The question is not one that science is going to answer,” Wolf said. “Science cannot answer the question whether stem cells are persons. Science cannot answer whether the destruction of stem cells should constitute murder. Those are social reasons, reasons that are not scientific. They’re policy-based reasons.”

Although embryonic and fetal stem cell research is limited, there are many opportunities for research on other types of stem cells.

“You’ve got stem cells in your skin. You could donate some of your own cells, and there’s no problem using those cells for research,” Wolf said. “Embryonic cells are different from the skin cells that I might give as a sample because they have the potential to develop into a human being.”

Donald Sakaguchi, associate professor of genetics, development and cell biology, only conducts research on adult stem cells.

“I don’t work with embryonic stem cells,” Sakaguchi said. “An important consideration for people who use embryonic stem cells is that they can form teratomas — like a tumor. So regulating these is not trivial.”

Unlike embryonic stem cells, umbilical cord stem cells do not have as much potential to give rise to cancer. However, they have to be isolated from differentiated cells before they can be used, while embryonic cells do not.

“In the umbilical cord, most of [the stem cells] have already differentiated into blood,” said Jitka Ourednik, associate professor of biomedical sciences. “But in embryos you have everything in very pre-mature stage, so they have probably higher potential to develop and to differentiate.”

Ourednik presented research on replacement therapy, in which neural stem cells have the potential to induce host cell regeneration.

Sakaguchi presented research on transplanting adult stem cells into the eye, which could eventually help treat retinal degenerative diseases such as glaucoma.

“The ultimate goal would be to restore vision in a blind individual,” Sakaguchi said. “It’s a work in progress in that the more you do, the more you learn, based on results from experiments.”