Danith Ly to study stem cells

In the Mellon Institute, within a freezer kept at -80 degrees Celsius, sits a human embryonic stem cell - a cell with the amazing ability to form any cell in the body. The cell originates from Monash University in Australia, and is the basis of Danith Ly's work. Ly, an assistant professor of chemistry, is hoping to find new ways of reproducing stem cells and using them to create other cells.

Ly has not yet begun the study of stem cells, but is planning to test for a method of fostering stem cell replication.

Stem cells have generated a frenzy of excitement because they have the potential to eventually cure illnesses such as Parkinson's disease, heart disease, diabetes, and Alzheimer's disease.

Embryonic stem cells (ESCs) are characterized by the term totipotent - the ability to give rise to every cell in the body.

Adult stem cells (ASCs) are known as multipotent - having only the ability to form other cells in their class. For example, adult blood stem cells could form red blood cells.

Embryonic stem cells are also capable of indefinite self renewal. Unlike normal cells, which die after a certain number of divisions, ESCs are capable of replicating an unlimited number of times - but only under the right conditions.

ESCs develop during the first stage of the development of a fetus. On about the fifth day of cell division, ESCs exist in the embryo - but only for a very short period of time. The ESCs quickly begin to differentiate into other cells.

Stem cells have come under the scrutiny of government and media in the past year. Some are concerned that research and availability of stem cells might lead to human cloning. President Bush has placed limitations on stem cell research, and has recommended a complete ban of human cloning. However, Ly says his research would not affected by this because the stem cell line he is working with has already been approved for use.

In August of last year, Bush announced that stem cell research would be limited to existing cell lines. However, there are currently only a handful of cell lines available. This may make it difficult to study stem cell capabilities, and to confirm the results. "You can not make any conclusions from one cell line," said Ly. "You have to test at least five or ten."

Some scientists are studying the potential of ASCs, but these cells are much more difficult to obtain. "As you grow older, the number of adult stem cells decreases greatly," said Ly. "So it may be hard to find (and harvest) ASCs."

Past studies have claimed that blood ASCs could transform into other cells such as nerve cells. However, researchers found last week that these claims may not have been true.

It is thought that the adult stem cells may have been simply merging with existing nerve cells. This gives the appearance of having formed a nerve cell, but the cell will have twice the amount of DNA, making the cell genetically useless.

One problem facing stem cell researchers is that ESCs can be rejected if implanted into the body. The body may treat the cells as foreign elements and reject them. According to Ly, a solution to this lies in therapeutic cloning. With therapeutic cloning, an adult stem cell from a subject's body is injected into an embryo, and this then grows into a blastocyst, which provides ESCs. These ESCs, which are based on the subject's native adult stem cells, can now be implanted into the body without rejection.