Crash Course: an in-depth look at stem cell research

By Kirstin Riggs 2007

One cell.
Debate sears the country over this cell, for within it lie cures, hope for incurable diseases. This powerful cell, the nucleus of the great debate, is a stem cell.

Stem cells are master cells from which all types of cells in the body are derived. Scientists have harnessed the power of stem cells to a degree to become specific tissues used to help treat diseases.

Stem cells are split into three categories, based on their source: adult, embryonic and neonatal. Embryonic stem cells are taken from an embryo, resulting in the destruction of the embryo. Adult stem cells are taken from living humans like bone marrow, fat, the brain or skin. Neonatal stem cells are taken from the placenta, amniotic fluid or umbilical cord blood.

Embryonic Moral Dilemma
The debate begins with moral arguments against embryonic stem cell research. Some feel that embryonic stem cell research holds the most promise of the three because they are more pluripotent, meaning they have more ability to develop into many different kinds of tissues. However, it requires the destruction of an embryo (which many people consider to be a human) for the potential cure for a disease. Adult and neonatal stem cell research does not pose this moral dilemma.
Doctor Randall Bremner opposes embryonic stem cell research. “Our knowledge base in embryonic stem cell research is in its infancy compared to what we know about the use of adult stem cell research.

In addition, embryonic stem cell research has several major disadvantages,” Bremner said.

These disadvantages include their tendency to form malignant (cancerous) tumors, their inability to be accepted by human immune systems and our inability to control the growth and differentiation of the stem cells into various tissues.

“My view is that life begins at conception, and as a society we should strive to protect the weakest and most vulnerable members of that society,” Bremner said. “Research dollars should be more wisely directed toward pursuing alternative sources of stem cells such as those found in amniotic fluid that don’t have all the problems associated with embryonic stem cells.”

Cures with Adult Stem Cells
Adult stem cells, Bremner added, have none of the ethical concerns of embryonic stem cells. “Adult stem cells can be taken from the patient and genetically matched, and thereby
not rejected by that patient’s own immune system,” Bremner said.

Adult stem cells are currently used in over 1,200 clinical trials. On April 4, British scientists used adult stem cells to create human heart valves, which heart surgeon Sir Magdi Yacoub, who led the team, said could be used in transplants within three years. A whole heart, he told the Guardian newspaper, could be produced from stem cells within 10 years.
Only a few days later on April 10, news of a cure for diabetics hit the presses. Thirteen young diabetics in Brazil underwent a procedure and then left with no need for treatment again.

In this procedure the doctors stimulated the body to produce stem cells and then harvested them from the patient’s blood. After wiping out their immune system through several days of chemotherapy, the doctors then injected the stem cells back into the body. The stem cells then build a new immune system that does not attack the insulin-producing cells, thereby curing all but two of them.

“It’s the first time in the history of Type 1 diabetes where people have gone with no treatment whatsoever … no medications at all, with normal blood sugars,” said Dr. Richard Burt of Northwestern University’s medical school in Chicago in a story that ran in the Des Moines Register.

These breakthroughs are only two of 1,200 clinical trials related to adult stem cells, versus zero clinical trials in humans related to embryonic stem cells.

Bill Supports Embryonic
Despite overwhelming evidence for adult stem cell research, politicians continue to pursue embryonic stem cell research. The Senate voted on April 11 to ease restrictions on federally funded embryonic stem cell research. The vote 63 to 34 is not enough to override the President’s expected veto, but Iowa Senator Tom Harkin remains enthusiastic about the bill.

“The overwhelming majority of Americans—and their members in Congress—want to take the shackles off of researchers. They want to move forward with some of the most exciting and promising research of modern times,” Harkin said

The bill Harkin supports, called S. 5, would allow the “400,000 leftover, unwanted embryos” in fertilization clinics to be used for embryonic stem cell research. “They are being discarded daily,” Harkin said.

However, these embryos may not be as “unwanted” as Harkin claims. Couples can adopt these frozen embryos, as 84 families have done in this country already. These adopted embryos, called “Snowflake Babies,” are proof that these embryos can, indeed, become human.

In spite of this, Harkin and many other politicians continue to pursue embryonic stem cell research, appealing to the public’s emotions to support the bill.

“First and foremost, S. 5 is about giving hope—real hope—to millions of people in this country suffering from juvenile diabetes, ALS, Parkinson’s, spinal cord injuries and many other devastating diseases and conditions,” Harkin said. What Harkin does not acknowledge is that all of these diseases he listed can currently be treated using adult stem cells. Patients do not need hope; they need the knowledge of treatments available.

Monetary Motives
With such evidence for adult stem cell research, why would politicians support embryonic? According to Bremner, it boils down to money. “Biotech patent attorneys claim that millions of dollars would be awarded to anyone who was able to patent embryonic stem cells for human use. In contrast, no such patent is possible with adult stem cells.” These patents are not available for adult stem cells because they are taken from the patient’s own body. An embryo, on the other hand, can be created and patented, thus making money.

As the debate rages on, Bremner relates the debate over stem cell research to the debate over slavery. “Abraham Lincoln once said when referring to slavery, ‘Some things that are legally right are not necessarily morally right.’ As a society, we are going to have to address the same issue as it pertains to the use of embryos in research. Are embryos merely property or people? As we advance in science, should we as a society strive to protect the weakest and most vulnerable or not? As the President’s Council of Bioethics stated recently, ‘We must make certain we don’t force ourselves into a false choice between science and ethics—because we need both.’”

Side Bar Story:
Back to Basics: What are stem cells?
Stem cells are master cells from which all types of cells in the body are derived. Scientists (to a degree) have harnessed the power of stem cells to become specific tissues used to help treat diseases.

What is In Vitro Fertilization (IVF)?
IVF is the process of combining a sperm with an egg to create an embryo. These embryos are then implanted into a woman’s uterus. Hundreds of embryos may be created for each pregnancy, the leftovers frozen after a success. The nation has 400,000-plus embryos frozen. What to do with these embryos is a heated debate among politicians. They could be used for stem cell research, which would require their destruction, or they could be “Snowflake Babies,” adopted by other women.

What is Somatic Cell Nuclear Transfer (SCNT)?
SCNT is a fancy term for cloning. The nucleus of an unfertilized egg is removed and replaced with the genetic information of the egg’s donor. This produces a cloned, one-cell embryo that will eventually grow to full term. Dolly the Sheep is the most famous example of a cloned animal. Dolly was the only clone out of 277 cloned embryos to survive to live birth (human cloning is even more difficult to accomplish). Even then she lived to be six years old (half the average life-span of a healthy sheep) and experienced a number of medical problems and had to be euthanized. Typically, cloned embryos are destroyed for stem cell research (cloning for scientific use is called Therapeutic Cloning. This is legal in Iowa. Reproductive Cloning, bringing a cloned human embryo to birth, is illegal in Iowa.)

There are three categories of stem cell research:
1. Embryonic – these cells are taken from an embryo. These embryos are supplied either by In Vitro Fertilization (see below), Somatic Cell Nuclear Transfer (see below), or from aborted fetuses. In all cases, the embryo is destroyed when the stem cells are taken.
-Pro’s: Great potential to turn into many different kinds of tissues.
-Con’s: Never have been used successfully. When implanted into a patient, these cells create tumors and are rejected by the body. Cell growth is difficult to control. Moral issue arises because embryonic stem cell research requires the destruction of human embryos.
2. Adult – these cells are taken from living humans
-Pro’s: Used successfully to treat many diseases today. A human patient can be his or her own stem cell donor, therefore avoiding a problem with rejection. On April 2 researchers at Harefield hospital in England managed to grow tissue that works in the same way as human heart valves. Other diseases treated with adult stem cells include leukemia,
-Con’s: Are not as pluripotent (meaning they can not turn into as many different kind of tissues) as embryonic.
3. Neonatal – these cells are taken from the placenta, amniotic fluid or umbilical cord blood.
-Pro’s: Are as pluripotent as embryonic stem cells without the moral issues of destroying an embryo. Do not cause rejection. Cells are easier to obtain. They grow faster in the lab than adult stem cells.

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