Stem cells in the news

On March 9, 2009, President Barack Obama signed an executive order which lifted the ban on stem cell research put there by the Bush administration. The Bush policy banned the use of federal monies for research on human embryonic stem cell lines that were created after August 9, 2001. This policy was unpopular with many scientists who believed that stem cell lines created before that date are inadequate for the development of therapies because the technologies for creating stem cells was not advanced enough. In addition, the existing human embryonic stem cell lines were created using products derived from animals such as serum used in the media to feed the cells. This again makes the cells inadequate for regenerative therapies which involve putting stem cells in to human beings.

On the other hand, people who opposed stem cell research liked the restrictions the Bush administration put on stem cell research. Human embryonic stem cells are derived from a fertilized embryo in a dish. There are people who feel that because these cells have the potential to become a person when implanted in a woman's womb, it is unethical to do stem cell research.
It is this controversy that makes stem cell research such big news.

In any case, the lift on the ban by Obama, means that federal funds can be used to conduct research on a wider variety of stem cell lines than was previously possibly, thus enabling the search for cures and therapies for human disease

What are stem cells ?

Human embryonic stem cell pluripotency Human embryonic stem cell culture

So what are stem cells? and what is the big deal? There are different types of stem cells and many of these types have existed for decades. For example, a bone marrow transplant is actually a Hematopoietic stem cell transplantation used to treat certain types of cancer. This type of therapy has existed since 1968. The first type of stem cell was discovered from a teratocarcinoma, a type of cancer, in 1964. Since then different types of stem cells have been derived. In 1998 James Thompson was able to derive the first human embryonic stem cell line. This was a break through because human embryonic stem cells (hESC's) have properties that set them apart from other types of stem cells. hESC's are pluripotent and the cells self renew.

Pluripotency means that the cells have the ability to become almost every type of cell in the body such as heart cells, liver cells or muscle cells. Most other types of stem cells are mulitpotent, which means that they have the ability to become different type of cells but only of a limited category. The other important property of hESC's is self renewal. This means that the cells that can make copies of themselves over and over again without undergoing senescence.

In 2008 another scientific breakthrough was made. Yamanaka a scientist in Japan was able to convert ordinary skin cells into pluripotent stem cells by inserting genes into them.These cells are called induced pluripotent stem cells (IPSC's). The genes that he inserted into the skin cells to convert them are genes that are naturally expressed in hESC's. This is very good news for the scientific community because it is now easier to gain access to pluripotent stem cells. It is also good news for the opponents of hESC research because the technique does not involve the destruction of human embryos. The down side is that IPCS's are made using viral vectors so are not suitable for human therapy. Although people are developing new methods to make IPSC's without using viral vectors. Furthermore, although IPCS's are very similar in properties to HESC's they are not 100% alike so more studies need to be performed with both types of cells to determine if indeed IPSC's can take the place of HESC's. None the less, IPSC's are very useful tools to develop in vitro models of disease and to test the efficacy of pharmaceutical drugs.

How can stem cells be used to cure disease ?

Diabetes Cardiovascular Disease

Pluripotent stem cells in culture are a model for human development and disease. These cells can differentiate into every type of cell in the body so these cells can be used to study the different proprieties of cell types, like what makes the cell normal or what makes the cell diseased. For example Type 1 diabetes is a disease where the pancreatic islets cells cannot produce insulin therefore people with this disease have to be on insulin therapy for life. Using pluripotent stem cells scientists have found ways to coax insulin production in certain type of pancreatic cells. In the future this type of technology can be used for human therapy.

Cardiovascular disease is another example, the adult heart cannot regenerate itself. This means that when certain parts of the heart become damaged such as in a heart attack, the body cannot repair the damaged heart and over time the function of the heart degenerates leading to heart failure and death. It is hoped that stem cells can be used to grow new heart cells that can be injected into patients for heart repair. Many of these regenerative therapies are still in the developmental stage using mouse models and cell culture models. We need to learn more about the properties of stem cells and safe ways to use them for human therapy.

Another application of stem cells is for drug development. When drugs are developed for heart disease for example, they are tested on animals or on cell cultures such as carcinoma cells. Neither of these systems are exactly like the cells in the human body. So when the drugs are actually used on humans they may suffer adverse reactions that was not anticipated by the developers because they did not have an adequate model to test the drugs. Now pluripotent stem cells from humans can be used to test drugs in order to evaluate adverse reactions.

Where can I find more information about stem cells?

There are numerous sources to find out about stem cells. When looking up stem cell resources you need to make sure it is from a reliable source. There is a lot of information on the Internet about miracle stem cell cures that is just a lot of hype. The best sources for stem cells are government websites such as the NIH, sources from disease foundations such as the American Heart Association. Also websites of scientific journals such as Nature, Science and Cell provide excellent resources.

NIH stem cell information home page http://stemcells.nih.gov/
California Institute for Regenerative Medicine http://www.cirm.ca.gov/
Stem cell information on Wikepedia http://en.wikipedia.org/wiki/Stem_cell
Stem Cell http://www.stemcells.com/view/0/index.html
Nature http://www.nature.com/
Science http://www.sciencemag.org/magazine.dtl

Is there a stem cell study that I can participate in ?

There are ongoing research studies which are testing the ability of stem cells to treat diseases. To find out about clinical trials search ClinicalTrials.gov

ClinicalTrials.gov http://clinicaltrials.gov/