Cures and Clones: Stem Cells in the News

by Chana Palmer, Stanford University

For millions of people around the world, stem cells offer the only glimmer of hope for a cure to their disease. Stem cells are a special type of cell that many scientists believe may one day be able to help correct many conditions previously thought incurable; from leukemia to paralysis to Parkinson's. In fact, some types of stem cells are already being used successfully to help treat children with certain rare diseases.

Illustration by Sue Medaris/UW-Madison University Communications.
Courtesy of UW-Madison, Embryonic Stem Cells homepage

If stem cells have such potential to relieve suffering, why are so many people so upset about their use? The reason is that the most powerful type of stem cell-embryonic stem (ES) cells-can only be obtained from human embryos. Many people think that it's wrong to create and destroy human embryos to treat disease.

What makes a stem cell so special and so powerful? There are two important ways in which stem cells are different from other cells in your body. The first is that they are unspecialized—this means that they don't have a specific job yet, and can take on any one of many specialized jobs later in their life. In this way, stem cells are like high school students who have yet to decide on their career and have the potential to be anything, whereas the rest of the cells in your body are already professionals. The second important quality of stem cells is that they can keep growing and making copies of themselves for many years. Here, again, stem cells are like teenagers...they can have many children over many years whereas most cells in the body are like middle-aged adults with only a few fertile years left.

Are all stem cells the same? No, in fact there are several quite different types of stem cells. The types differ by where they are in the body and by what they can become. The most important distinction to make is between adult stem cells and embryonic stem cells. Adult stem cells are found in adults and children while embryonic stem cells (not surprisingly) are found ONLY in embryos. Embryonic stem cells are the most flexible and potentially useful type of stem cell. Unlike adult stem cells, which have a limited range of "careers" available to them, embryonic stem cells can turn into almost any cell type: blood, heart, liver, bone...ES cells are child prodigies! Unfortunately, ES cells are also the most difficult to obtain, both practically and ethically.

Below are two articles describing current advances in stem cell research. One of the articles tells a success story in the US for the use of umbilical cord stem cells in treating heart disease and the other reports an advance by South Korean scientists in "cloning" a human embryo and obtaining human ES cells.

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To learn more about stem cells

Stem cells proven to treat heart damage

For the first time ever, scientists were able to show that stem cells from a healthy donor baby's blood can transform into the specialized cell type that a patient needs. The patient was a four-year old boy with Sanfilippo Syndrome B, a rare disease which, when left untreated, results in liver, heart and brain failure. The boy was given healthy stem cells from the blood of a baby girl in the hopes that once inside the boy's body, the healthy stem cells would keep his vital organs from failing. Even though the boy eventually died from infection (one of the common risks associated with transplants), doctors were able to show for the first time that some of the girl's healthy cells had settled in the boy's heart and transformed themselves into fully functional heart cells.

Notably, blood stem cells have been used for years to treat children with liver, brain and heart problems. It was suspected that donor stem cells were transforming themselves into the needed cell types, but until this study, this phenomenon had never been proven.

The study was conducted by a team or researchers at the Duke Comprehensive Cancer Center. Kirsten Crapnell, Ph.D will present the team's findings at the International Association of Bone Marrow Transplantation Research meeting Feb. 12-17 in Orlando, Florida.

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Cord Blood Cells Proven to Differentiate Into Heart Muscle, Brain Cells

Human embryo created by cloning

Say it ain't so, Joe! Or should I say Hwang Woo Suk? Unfortunately, the results we talk about in this part of the article have been shown to be false. Investigations are currently ongoing to see if the data was deliberately falsified.

The ideas still stand and one day scientists will do what Hwang Woo Suk has claimed he has done. It will be just a matter of time—thank goodness science is self correcting!

Scientists in South Korea announced the creation of the first cloned human embryos, an exciting but scary advance in human cloning technology. The embryos are genetically identical to their mother/donor and were created for the sole purpose of using their embryonic stem cells for medical research and therapy. Embryonic stem cells can only be found in embryos and, because they can transform themselves into just about any cell type, have the potential to treat or cure many different human diseases. This type of cloning—"therapeutic cloning" should not be confused with "reproductive cloning"—the creation of cloned embryos to be grown into full term babies. The embryos were created by removing the nucleus (DNA) from eggs of volunteering women, and injecting the nucleus (DNA) from one of their adult cells back into their egg. This procedure has previously been done in some animals—horses, sheep, rats—but this report is the first in humans. Since this type of work is so ethically controversial, US and may other countries are working hard on developing regulations for the use of stem cells, with special focus on embryonic stem cells.

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Content provided by the Department of Genetics, Stanford University.