What Is a Stem Cell

“What You Need to Know about Stem Cells”

Presenter’s Notes Accompanying the PowerPoint Presentation

Prepared by the

Stem Cell Action Network (SCAN)

The notes in this documentamplify information in the SCAN PowerPoint presentation on stem cell research. You can use these notes to help you give this presentation to an audience. Additional materials that you may find helpful in preparing your presentation are available online at:

The presentation and these notes are designed to serve the needs of a presenter who is not a scientist and who does not know much about stem cell research. Please don’t be intimidated by the complexity of this subject! Technical expertise is not needed to give this presentation.

These notes are posted on the SCAN website at Encourage those in your audience who have Internet access to read these notes if they wish to learn more about the points made in your presentation.

Also helpful in “boning up” on the basics of SCR (stem cell research) are the following online resources:

Regarding the science of stem cell research:

Princeton University Department of Molecular Biology

Stem Cell Network (a Canadian organization)

National Institutes of Health (NIH) Stem Cell Information

Regarding he ethics of stem cell research:

Stem cell research is a many-faceted enterprise. In preparing your presentation, don’t feel that you have to cover every single point made on the slides. And don’t be daunted by the amount of material that we’ve included in these notes. We realize that this is much more information here than would ever be fitted into a talk on this subject.

Tailor what you say to the needs and attention span of your audience. Choose whatever you believe will be relevant and helpful to that audience. If questions are thrown at you that you cannot answer, then relay them to us at SCAN (), and we will try to reply in a timely way.

Here are addition guidelines.

1. There are several ways of giving this presentation to an audience. If you do not have access to PowerPoint presentation technology, then you may take a “low-tech” approach, using only printed materials. Especially for an audience of ten or twenty or so, that will work fine.

1. Whatever form your presentation takes, it’s a good idea to accompany your talk with a printed document that you hand out to members of your audience. You can make copies of the Word-document version of the presentation at your local photocopy shop and distribute them to your audience. (This document includes the two slides on California. You may delete them if you're addressing a non-California audience.)

1. You can also ask the photocopy shop to make 11X17 inch color representations of the three explanatory diagrams in the presentation:

1. "Embyronic Stem Cells”
2. “Stem Cells from In Vitro Fertilization (IVF)”
3. “Human Therapeutic Cloning (SCNT)”

For a diagram that combines diagrams 2 and 3 above, see: "IVF and SCNT Stem Cell Sources"

By clicking on these images (try using a right-click, if your mouse has one), you can download them to your computer. You can then email them to your local photocopy shop, to be printed out in 11X17-inch color. Kinkos will do this for less than $2/slide. If your audience is a small one, you can display the printed images to them while you discuss the scientific aspects of the research.

In June, we will hold the "First International Stem Cell Action Conference" at the University of California in Berkeley. Please invite your audience members to attend this historic event. You can download, copy, and distribute the Conference Flier to your audience.

1. You can go to your local photocopy shop and ask them to make 11X17 inch color representations of the three explanatory diagrams in the presentation, entitled

• “Embyronic Stem Cells”
• “Stem Cells from In Vitro Fertilization”
• “Human Therapeutic Cloning (SCNT)”

For a diagram that combines the last two diagrams above, see: "IVF and SCNT Stem Cell Sources"

Files containing these images are posted at

By right-clicking on these images you can download them to your computer. You can then email them to your local photocopy shop, and they can print them out in 11X17 color. Kinkos will do this for less than $2/slide.

It is a good idea to accompany your talk with a printed hand-out that you distribute to members of your audience. We have prepared such a hand-out and it is available at:

1. You presentation is an overview, and in most cases shouldn’t last longer than 30 to 45 minutes. You don’t want to lose the interest and attention of your audience.

1. The most important parts of your presentation are likely to be the science, ethics, and advocacy of the research. You may wish to focus on these three areas, giving less attention to the details of the political regulation and support for the research.

1. Be sure to hand out to your audience the flier about the conference, and invite audience members to attend. Encourage members to learn more about the conference by visiting the website. and/or telephoning Raymond Barglow, whose phone number is at the bottom of the flier. (The conference flier is included as Appendix 3 of this document, and is also available on line at

1. Ask audience members to provide you with their email addresses, if they are willing to be added to the SCAN emailing list or if they have an interest in the conference.

1. Encourage discussion during or following your presentation. Be open to questions that audience members ask about any aspect of the research – scientific, ethical, or political. If people have qualms about the prospects or ethics of the research, they should feel free to express them. Please remain tolerant and friendly toward people who question the research for one reason or another.

Slide: What are stem cells?

Stem cells are the raw material from which all of the body’s mature, differentiated cells are made. Stem cells give rise to brain cells, nerve cells, heart cells, pancreatic cells, etc.

The cells that make up a human body are of different types and specialize in doing specific kinds of work, just as in society, different people have different jobs. All cells, however, either are stem cells or come from stem cells. Cellsof the heart, the brain, bones, the pancreas – whatever kind of cell you care to mention –all have their origins in the versatile stem cell.

Once a stem cell has specialized, however, itcannot develop intoyet another type of cell. Stemcells don’t get to change careers -- cell differentiationis an irreversible process.

Stem cells are found in embryos during their first few days of development, in fetal tissue, and more rarely in organs such as the heart, bones, brain, etc.

Slide: What’s so special about stem cells?

• They are self-renewing -- they can replicate themselves over and over for a very long time.

• They have the potential to replace cell tissue damaged by severe illnesses.

• Understanding how stem cells develop into healthy and diseased cells will assist the search for cures.

Stem cells are a raw material that has the capacity to renew itself. Stem cells candivide over and over, for a very long time, generating an unlimited number of identical undifferentiated cells exactly like themselves. A stem cell “line” is composed of a culture of self-replicating stem cells.

Stem cellsgenerate all of the cell types that a human body needs. Stem cells’ two key properties – their self-renewing capacity and their capacity to become mature, specialized cells -- make them well suited to restoring tissue that has deteriorated. Like a very versatile building material, stem cellscan be molded into just the right form to repair a human body.

Let’s look at this restorative process in a little greater detail, to better understand how stem cell research can lead to cures. Some children are born with organs that do not work right. A child with juvenile diabetes, for example, has a pancreas that does not generate enough insulin – a hormone needed by the body in order to digest sugars.

Adults too sometimes have cells or entire organs that have become damaged so that they no longer function well. In the brain of a person who has Parkinson’s or Alzheimer’s disease, for example, neurons no longer work in the normal way. In a spinal cord injury, crushed or damaged cells cause paralysis. In a heart attack, heart muscle is destroyed and replaced by useless scar tissue. In each of these cases, the result is illness, disability, and suffering.

Doctors and scientists have long been looking for a way to replace damaged or worn-out tissue in the human body with new healthy tissue, thereby giving patients a new lease of life. The most promising path to cures is the regeneration of differentiated tissue from stem cells, and especially from embryonic stem cells which are the most plastic and versatile cells in the human body. Research using these cells may yield the cures needed by the nearly 100 million Americans afflicted by conditions ranging from Parkinson’s, Alzheimer’s diseases, heart disease, and spinal cord injury to juvenile diabetes, multiple sclerosis, ALS, and many other medical conditions.

It is, however, NOT only in the domain of regenerative medicine that stem cells will prove medically useful. Here are two additional valuable applications of the research:

1. Scientists will observe and learn how stem cells give rise either to normal differentiated cells or to diseased ones. Discovering in this way how diseases begin and develop will help us find more effective treatments and cures.

1. Stem cell research can also assist in the testing of drugs for safety and effectiveness. Before trying a new drug out on human subjects, we can see how it affects the development of stem cells into healthy or diseased tissue.

Slide: Two kinds of stem cells

• Embryonic (also called “pluripotent”) stem cells are capable of developing into all the cell types of the body.
• Adult stem cells are less versatile and more difficult to identify, isolate, and purify.

Scientists work with both embryonic and adult stem cells. These two kinds of stem cell have quite different properties, and research using both is essential – the research will advance most effectively if it “walks on two legs,” so to speak.

We don’t yet know which kind of stem cell – embryonic or adult -- will prove to be most useful for medical purposes. Studies done on both stem cell types are likely to play an essential role in finding new treatments and cures.

Most scientists believe, however, that embryonic stem cells are the more promising because they are “pluripotent,” meaning that they have the potential to differentiate into tissue of any organ (brain, liver, heart, pancreas, etc.) of the human body. Adult stem cells, on the other hand, are, at best, "multipotent," meaning that they generate just a few tissue types.

Adult stem cells exist in small amounts throughout the body. They are relatively rare, however, and less plastic (capable of transforming into diverse cell types) than are embryonic stem cells. Adult stem cells taken from the skin only become skin, cartilage cells only become cartilage, etc. An additional problem with adult stem cells is that they don’t replicate well in a lab – so it’s difficult to obtain enough of them to work with.

Embryonic cells hold more promise than adult ones for two additional purposes that we’ve already mentioned: 1) understanding the origins and development of disease processes, and 2) testing new drugs.

It should be noted, however, that to date, only adult stem cells have been used successfully in medical therapies – most notably in treatments for non-Hodgkin’s lymphoma and Leukemia. Embryonic stem cells have been used successfully for treatment purposes in animal studies, but have not yet been shown to be effective for human beings.

Moreover, using adult stem cells in medical treatment may have one significant advantage over embryonic stem cells – the adult cells may be less likely than embryonic ones to stimulate the growth of tumors. This is a potential problem that regenerative medicine may need to address and solve.

Research using embryonic stem cells hasn’t been around as long as research using the adult variety. But the pluripotency of these cells – their capacity to generate all of the body’s cell types -- may make them especially useful in understanding and healing illnesses of tissue deterioration or loss.

Slide: Embryonic Stem cells

Researchers extract them from a 5-7 days old blastocyst.

They can divide to form more of their own kind, thereby creating a stem cell line.

This research aims to induce these cells to regenerate tissue that the body needs.

• Embryonic stem cells are found in a days-old embryo called a blastocyst. A blastocyst is a ball ofbetween 128 and 256 cells that exists from about day 5 to day 7 following conception.

• The ES cells in a blastocyst are part of the inner cell mass (ICM). These cells are removed from the blastocyst and cultured – in a petri dish for example -- where they can be kept alive and encouraged to reproduce, thereby creating a stem cell line. This procedure destroys the blastocyst.

• ES cells are pluripotent - they have the ability to become any type of cell in the body (except for cells in the placenta or umbilical cord, which are generated out of the cells surrounding the ICM.

• The medical potential of stem cells has convinced many people to support stem cell research, including research that works with embryonic stem cells. One of the most famous advocates of ES cell research is Michael J. Fox. He has Parkinson’s Disease, and is the founder of the Michael J. Fox Foundation, an organization that supports Parkinson’s Disease research. Of the $17 million donated so far, over $4 million has gone to ES cell research.

• Another famous advocate of ES cell research is Christopher Reeve, the star of the Superman movie series. When he was thrown from a horse, he severed his spine, losing the use of his arms and legs. He regularly speaks on the importance of ES cell research as a possible cure for his and other conditions.

• Embryonic stem cell research is a very young science, and may have a long way to go before it yields medical benefits. It is noteworthy, though, that the curative potential of stem cells has already been demonstrated in animal studies. Here are three examples:

1. Parkinson’s Disease. A team led by Lorenz Studer, M.D. at the MemorialSloan-KetteringCancerCenter, working with scientists from CornellUniversity and the University of Connecticut, used cloned cells to generate dopamine nerve cells in mice – these are the cells that Parkinson's patients lack. The cloning technique insured that these cells would be immunologically acceptable to these mice. The mice had a disease very similar to Parkinson's, which the experimental therapy alleviated. Possibly this kind of therapy can be made to work with human beings as well.

1. Juvenile Diabetes. "Diabetes," the journal of the American Diabetes Association (July 25, 2003), reports that researchers at the Univ. of Wisconsin observed mouse embryonic stem cells differentiate into a variety of specialized cells, including insulin-producing cells. Therapeutic cloning to generate such cells may solve problems facing promising therapies like the Edmonton protocol.

The Edmonton protocol is a procedure developed in Canada for transplanting healthy, insulin-producing islet cells into people with Type 1 diabetes. Most Edmonton protocol treatments are quite successful – experimental data indicate that the transplanted cells continue to generate insulin for years. Two factors, however, limit the usefulness of this protocol:

1) Pancreatic islet cells are rare, and 2) the treatment induces a rejection response by the body’s immune system. The second of these problems all but rules out the use of this treatment for children with juvenile diabetes. Therapeutic cloning – as we will see in a moment -- could solve both of these problems.

1. Spinal cord injury. A number of studies done on animals with spinal cord injuries have shown that stem cell transplants are capable of treating these injuries. For example, a research team at the University of California at Irvinehas demonstrated that when cells derived from human embryonic stem cells were transplanted into rats that had received a spinal cord injury, improvements in the animals’ ambulatory activity could be observed approximately one month later.

Slide: Two Sources of Embryonic Stem Cells