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Stem cell research has become a big debate between since and religion based on one central question; "when does life begin?"(Watson). As of now the only way to harvest stem cells is though a conceived embryo or an egg donation, unfortunately both of these methods destroy the embryo.

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Stem cell research has become one of the biggest issues dividing the scientific and religious communities around the world. At the core of the issue is one central question: When does life begin? At this time, to get stem cells that are reliable, scientists either have to use an embryo that has already been conceived or else clone an embryo using a cell from a patient's body and a donated egg. Either way, to harvest an embryo's stem cells, scientists must destroy it. Although that embryo may only contain four or five cells, some religious leaders say that destroying it is the equivalent of taking a human life. Inevitably, this issue entered the political arena.

In 1996, Congress passed a rider to the federal appropriations bill called the Dickey-Wicker amendment. Representatives Jay Dickey and Roger Wicker proposed banning the use of federal monies for any research in which a human embryo is created or destroyed. Federal monies are a primary source of funding for stem cell research. The amendment has been renewed every year since that time.

In 2001, President George W. Bush further restricted federal stem cell research. In an executive order, Bush stated that federal funds could only be used for research on human embryonic stem cell lines that had already been established (only 22 cell lines). This prevented researchers from creating more embryonic stem cell lines for research.

In 2009, President Barack Obama issued an executive order to expand embryonic stem cell research. Obama's administration allowed federal funding of embryonic stem cell research if the following conditions applied:

The cell line was one of the 22 in existence during the Bush administration or was created from embryos that had been discarded after in vitro fertilization procedures.

The donors of the embryos were not paid in any way.

The donors clearly knew that the embryos would be used for research purposes prior to giving consent.

According to the administration, the new policy did not violate the Dickey-Wicker amendment because the money did not finance the creation of new embryos (they had already been created by private means) and did not finance the destruction of them.

In 2009, two researchers from Boston, Dr. James Sherley of the Boston Biomedical Research Institute and Dr. Theresa Deisher of the Ava Maria Biotechnology Company, and other agencies filed a lawsuit against the government. Initially, the lawsuit was dismissed because the judge ruled that the plaintiffs had no legal standing (i.e. they were not affected materially by the new rules). However, a court of appeals overturned the initial ruling. The two scientists remained plaintiffs. The scientists claimed that, because they used adult stem cells exclusively in their research, the new rules would increase competition for federal research dollars, thereby affecting their ability to obtain funding. Federal Judge Royce Lamberth upheld the appeals court ruling. He placed an injunction preventing the new rules from going into place. He claimed that the rules violated the Dickey-Wicker amendment because embryos must be destroyed in the process of creating embryonic stem cell lines.

In September 2010, The New York Times reported that the U.S. Court of Appeals ruled that federal funding of embryonic stem cell research could continue under the new rules while the court considers Judge Lamberth's ruling [source: New York Times]. This ruling allows researchers to continue feeding embryonic stem cell cultures, experimenting with mice, and other research activities until this court rules, the U.S. Supreme Court weighs in, or Congress passes legislation that clarifies the issues. In the meantime, stem cell research and the careers of stem cell researchers hang on a legal roller coaster. Although stem cells have great potential for treating diseases, much work on the science, ethical and legal fronts remains.

For more on stem cells, investigate the links on the following page.

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Stem cell research has become one of the biggest issues dividing the scientific and religious communities around the world. At the core of the issue is one central question: When does life begin?

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A Stem Cell is most easily described as a base cell that can be changed, grown, or formed into any type of cell created in the body, like nerve or skin cells.

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What is a Stem Cell? | SCRF - Charlotte Lozier Institute

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Adult Stem Cells serve as a built-in repair system to replenish cells in patients who suffer from diseases. Learn about ground-breaking discoveries in science and medicine.

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There are many different ways you can harvest stem cells. It all depends on the source of the stem cells. For instance, " stem cells can be collected from bone marrow, circulating (peripheral) blood or umbilical cord blood."

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The Canadian Cancer Society is a national community-based organization of volunteers whose mission is the eradication of cancer and the enhancement of the quality of life of people living with cancer.

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They create cells that are healthy to kick out the unhealthy cells.

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Stem cells: What they are and what they do
Stem cells and derived products offer great promise for new medical treatments. Learn about stem cell types, current and possible uses, ethical issues, and the state of research and practice. By Mayo Clinic Staff
You've heard about stem cells in the news, and perhaps you've wondered if they might help you or a loved one with a serious disease. You may wonder what stem cells are, how they're being used to treat disease and injury, and why they're the subject of such vigorous debate.

Here are some answers to frequently asked questions about stem cells.

Why is there such an interest in stem cells?

Researchers and doctors hope stem cell studies can help to:

Increase understanding of how diseases occur. By watching stem cells mature into cells in bones, heart muscle, nerves, and other organs and tissue, researchers and doctors may better understand how diseases and conditions develop.

Generate healthy cells to replace diseased cells (regenerative medicine). Stem cells can be guided into becoming specific cells that can be used to regenerate and repair diseased or damaged tissues in people.

People who might benefit from stem cell therapies include those with spinal cord injuries, type 1 diabetes, Parkinson's disease, Alzheimer's disease, heart disease, stroke, burns, cancer and osteoarthritis.

Stem cells may have the potential to be grown to become new tissue for use in transplant and regenerative medicine. Researchers continue to advance the knowledge on stem cells and their applications in transplant and regenerative medicine.

Test new drugs for safety and effectiveness. Before using new drugs in people, some types of stem cells are useful to test the safety and quality of investigational drugs. This type of testing will most likely first have a direct impact on drug development for cardiac toxicity testing.

New areas of study include the effectiveness of using human stem cells that have been programmed into tissue-specific cells to test new drugs. For testing of new drugs to be accurate, the cells must be programmed to acquire properties of the type of cells to be tested. Techniques to program cells into specific cells continue to be studied.

For instance, nerve cells could be generated to test a new drug for a nerve disease. Tests could show whether the new drug had any effect on the cells and whether the cells were harmed.

What are stem cells?

Stem cells are the body's raw materials - cells from which all other cells with specialized functions are generated. Under the right conditions in the body or a laboratory, stem cells divide to form more cells called daughter cells.

These daughter cells either become new stem cells (self-renewal) or become specialized cells (differentiation) with a more specific function, such as blood cells, brain cells, heart muscle or bone. No other cell in the body has the natural ability to generate new cell types.

Where do stem cells come from?

Researchers have discovered several sources of stem cells:

Embryonic stem cells. These stem cells come from embryos that are three to five days old. At this stage, an embryo is called a blastocyst and has about 150 cells.

These are pluripotent (ploo-RIP-uh-tunt) stem cells, meaning they can divide into more stem cells or can become any type of cell in the body. This versatility allows embryonic stem cells to be used to regenerate or repair diseased tissue and organs, although their use in people has been to date limited to eye-related disorders such as macular degeneration.

Adult stem cells. These stem cells are found in small numbers in most adult tissues, such as bone marrow or fat. Compared with embryonic stem cells, adult stem cells have a more limited ability to give rise to various cells of the body.

Until recently, researchers thought adult stem cells could create only similar types of cells. For instance, researchers thought that stem cells residing in the bone marrow could give rise only to blood cells.

However, emerging evidence suggests that adult stem cells may be able to create unrelated types of cells. For instance, bone marrow stem cells may be able to create bone or heart muscle cells. This research has led to early-stage clinical trials to test usefulness and safety in people. For example, adult stem cells are currently being tested in people with neurological or heart disease.

Adult cells altered to have properties of embryonic stem cells (induced pluripotent stem cells). Scientists have successfully transformed regular adult cells into stem cells using genetic reprogramming. By altering the genes in the adult cells, researchers can reprogram the cells to act similarly to embryonic stem cells.
This new technique may allow researchers to use these reprogrammed cells instead of embryonic stem cells and prevent immune system rejection of the new stem cells. However, scientists don't yet know if altering adult cells will cause adverse effects in humans.

Researchers have been able to take regular connective tissue cells and reprogram them to become functional heart cells. In studies, animals with heart failure that were injected with new heart cells experienced improved heart function and survival time.

Perinatal stem cells. Researchers have discovered stem cells in amniotic fluid in addition to umbilical cord blood stem cells. These stem cells also have the ability to change into specialized cells.

Amniotic fluid fills the sac that surrounds and protects a developing fetus in the uterus. Researchers have identified stem cells in samples of amniotic fluid drawn from pregnant women during a procedure called amniocentesis, a test conducted to test for abnormalities.

More study of amniotic fluid stem cells is needed to understand their potential.

Why is there a controversy about using embryonic stem cells?

Embryonic stem cells are obtained from early-stage embryos - a group of cells that forms when a woman's egg is fertilized with a man's sperm in an in vitro fertilization clinic. Because human embryonic stem cells are extracted from human embryos, several questions and issues have been raised about the ethics of embryonic stem cell research.

The National Institutes of Health created guidelines for human stem cell research in 2009. Guidelines included defining embryonic stem cells and how they may be used in research and donation guidelines for embryonic stem cells. Also, guidelines stated embryonic stem cells may only be used from embryos created by in vitro fertilization when the embryo is no longer needed.

Where do these embryos come from?

The embryos being used in embryonic stem cell research come from eggs that were fertilized at in vitro fertilization clinics but never implanted in a woman's uterus. The stem cells are donated with informed consent from donors. The stem cells can live and grow in special solutions in test tubes or petri dishes in laboratories.

Why can't researchers use adult stem cells instead?

Although research into adult stem cells is promising, adult stem cells may not be as versatile and durable as are embryonic stem cells. Adult stem cells may not be able to be manipulated to produce all cell types, which limits how adult stem cells can be used to treat diseases.

Adult stem cells also are more likely to contain abnormalities due to environmental hazards, such as toxins, or from errors acquired by the cells during replication. However, researchers have found that adult stem cells are more adaptable than was initially suspected.

What are stem cell lines and why do researchers want to use them?

A stem cell line is a group of cells that all descend from a single original stem cell and is grown in a lab. Cells in a stem cell line keep growing but don't differentiate into specialized cells. Ideally, they remain free of genetic defects and continue to create more stem cells. Clusters of cells can be taken from a stem cell line and frozen for storage or shared with other researchers.

What is stem cell therapy (regenerative medicine), and how does it work?

Stem cell therapy, also known as regenerative medicine, promotes the reparative response of diseased, dysfunctional or injured tissue using stem cells or their derivatives. It is the next chapter of organ transplantation and uses cells instead of donor organs, which are limited in supply.

Researchers grow stem cells in a lab. These stem cells are manipulated to specialize into specific types of cells, such as heart muscle cells, blood cells or nerve cells.

The specialized cells can then be implanted into a person. For example, if the person has heart disease, the cells could be injected into the heart muscle. The healthy transplanted heart cells could then contribute to repairing defective heart muscle.

Researchers have already shown that adult bone marrow cells guided to become heart-like cells can repair heart tissue in people, and more research is ongoing.

Have stem cells already been used to treat diseases?

Yes, doctors have performed stem cell transplants, also known as bone marrow transplants. In stem cell transplants, stem cells replace cells damaged by chemotherapy or disease or as a way for the donor's immune system to fight some types of cancer and blood-related diseases, such as leukemia. These transplants use adult stem cells or umbilical cord blood.

Researchers are testing adult stem cells to treat other conditions, including a number of degenerative diseases such as heart failure.

What are the potential problems with using embryonic stem cells in humans?

To be useful in people, researchers must be certain that stem cells will differentiate into the specific cell types desired.

Researchers have discovered ways to direct stem cells to become specific types of cells, such as directing embryonic stem cells to become heart cells. Research is ongoing in this area.

Embryonic stem cells also could grow irregularly or specialize in different cell types spontaneously. Researchers study how to control the growth and differentiation of embryonic stem cells.

Embryonic stem cells also might trigger an immune response in which the recipient's body attacks the stem cells as foreign invaders, or simply fail to function normally, with unknown consequences. Researchers continue to study how to avoid these possible complications.

What is therapeutic cloning, and what benefits might it offer?

Therapeutic cloning, also called somatic cell nuclear transfer, is a technique to create versatile stem cells independent of fertilized eggs. In this technique, the nucleus, which contains the genetic material, is removed from an unfertilized egg. The nucleus is also removed from a somatic cell of a donor.

This donor nucleus is then injected into the egg, replacing the nucleus that was removed, a process called nuclear transfer. The egg is allowed to divide and soon forms a blastocyst. This process creates a line of stem cells that is genetically identical to the donor's - in essence, a clone.

Some researchers believe that stem cells derived from therapeutic cloning may offer benefits over those from fertilized eggs because cloned cells are less likely to be rejected once transplanted back into the donor and may allow researchers to see exactly how a disease develops.

Has therapeutic cloning in people been successful?

No. Researchers haven't been able to successfully perform therapeutic cloning with humans despite success in a number of other species.

However, in recent studies, researchers have created human pluripotent stem cells by modifying the therapeutic cloning process. Researchers continue to study the potential of therapeutic cloning in people.

See more In-depth

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Stem cells: FAQs about stem cell research

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Stem cells and derived products offer great promise for new medical treatments. Learn about stem cell types, current and possible uses, ethical issues, and the state of research and practice. By Mayo Clinic Staff You've heard about stem cells in the news, and perhaps you've wondered if they might help you or a loved one with a serious disease.

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Stem Cell research has been legal on humans since March 9, 2009 when Barrack Obama made an Executive Order to lift the band on Stem Cell research

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"Mesenchymal stem cells are multipotent adult stem cells that are present in multiple tissues, including umbilical cord, bone marrow and fat tissue. Mesenchymal stem cells can self-renew by dividing and can differentiate into multiple tissues including bone, cartilage, muscle and fat cells, and connective tissue."

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Tissue Specific stem cells are also called adult stem cells. "  The adult stem cell can renew itself and can differentiate to yield some or all of the major specialized cell types of the tissue or organ" (U.S. Department of Human Services).

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1. Introduction: What are stem cells, and why are they important?

2. What are the unique properties of all stem cells?

3. What are embryonic stem cells?

4. What are adult stem cells?

5. What are the similarities and differences between embryonic and adult stem cells?

6. What are induced pluripotent stem cells?

7. What are the potential uses of human stem cells and the obstacles that must be overcome before these potential uses will be realized?

8. Where can I get more information?

IV. What are adult stem cells?

An adult stem cell is thought to be an undifferentiated cell, found among differentiated cells in a tissue or organ. The adult stem cell can renew itself and can differentiate to yield some or all of the major specialized cell types of the tissue or organ. The primary roles of adult stem cells in a living organism are to maintain and repair the tissue in which they are found. Scientists also use the term somatic stem cell instead of adult stem cell, where somatic refers to cells of the body (not the germ cells, sperm or eggs). Unlike embryonic stem cells, which are defined by their origin (cells from the preimplantation-stage embryo), the origin of adult stem cells in some mature tissues is still under investigation.

Research on adult stem cells has generated a great deal of excitement. Scientists have found adult stem cells in many more tissues than they once thought possible. This finding has led researchers and clinicians to ask whether adult stem cells could be used for transplants. In fact, adult hematopoietic, or blood-forming, stem cells from bone marrow have been used in transplants for more than 40 years. Scientists now have evidence that stem cells exist in the brain and the heart, two locations where adult stem cells were not at first expected to reside. If the differentiation of adult stem cells can be controlled in the laboratory, these cells may become the basis of transplantation-based therapies.

The history of research on adult stem cells began more than 60 years ago. In the 1950s, researchers discovered that the bone marrow contains at least two kinds of stem cells. One population, called hematopoietic stem cells, forms all the types of blood cells in the body. A second population, called bone marrow stromal stem cells (also called mesenchymal stem cells, or skeletal stem cells by some), were discovered a few years later. These non-hematopoietic stem cells make up a small proportion of the stromal cell population in the bone marrow and can generate bone, cartilage, and fat cells that support the formation of blood and fibrous connective tissue.

In the 1960s, scientists who were studying rats discovered two regions of the brain that contained dividing cells that ultimately become nerve cells. Despite these reports, most scientists believed that the adult brain could not generate new nerve cells. It was not until the 1990s that scientists agreed that the adult brain does contain stem cells that are able to generate the brain's three major cell types- astrocytes and oligodendrocytes, which are non-neuronal cells, and neurons, or nerve cells.

A. Where are adult stem cells found, and what do they normally do?

Adult stem cells have been identified in many organs and tissues, including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. They are thought to reside in a specific area of each tissue (called a "stem cell niche"). In many tissues, current evidence suggests that some types of stem cells are pericytes, cells that compose the outermost layer of small blood vessels. Stem cells may remain quiescent (non-dividing) for long periods of time until they are activated by a normal need for more cells to maintain tissues, or by disease or tissue injury.

Typically, there is a very small number of stem cells in each tissue and, once removed from the body, their capacity to divide is limited, making generation of large quantities of stem cells difficult. Scientists in many laboratories are trying to find better ways to grow large quantities of adult stem cells in cell culture and to manipulate them to generate specific cell types so they can be used to treat injury or disease. Some examples of potential treatments include regenerating bone using cells derived from bone marrow stroma, developing insulin-producing cells for type 1 diabetes, and repairing damaged heart muscle following a heart attack with cardiac muscle cells.

B. What tests are used to identify adult stem cells?

Scientists often use one or more of the following methods to identify adult stem cells: (1) label the cells in a living tissue with molecular markers and then determine the specialized cell types they generate; (2) remove the cells from a living animal, label them in cell culture, and transplant them back into another animal to determine whether the cells replace (or "repopulate") their tissue of origin.

Importantly, scientists must demonstrate that a single adult stem cell can generate a line of genetically identical cells that then gives rise to all the appropriate differentiated cell types of the tissue. To confirm experimentally that a putative adult stem cell is indeed a stem cell, scientists tend to show either that the cell can give rise to these genetically identical cells in culture, and/or that a purified population of these candidate stem cells can repopulate or reform the tissue after transplant into an animal.

C. What is known about adult stem cell differentiation?

As indicated above, scientists have reported that adult stem cells occur in many tissues and that they enter normal differentiation pathways to form the specialized cell types of the tissue in which they reside.

Normal differentiation pathways of adult stem cells. In a living animal, adult stem cells are available to divide for a long period, when needed, and can give rise to mature cell types that have characteristic shapes and specialized structures and functions of a particular tissue. The following are examples of differentiation pathways of adult stem cells ( Figure 2) that have been demonstrated in vitro or in vivo.

Figure 2. Hematopoietic and stromal stem cell differentiation. Click here for larger image. (© 2008 Terese Winslow)

Hematopoietic stem cells give rise to all the types of blood cells: red blood cells, B lymphocytes, T lymphocytes, natural killer cells, neutrophils, basophils, eosinophils, monocytes, and macrophages.

Mesenchymal stem cells have been reported to be present in many tissues. Those from bone marrow (bone marrow stromal stem cells, skeletal stem cells) give rise to a variety of cell types: bone cells (osteoblasts and osteocytes), cartilage cells (chondrocytes), fat cells (adipocytes), and stromal cells that support blood formation. However, it is not yet clear how similar or dissimilar mesenchymal cells derived from non-bone marrow sources are to those from bone marrow stroma.

Neural stem cells in the brain give rise to its three major cell types: nerve cells (neurons) and two categories of non-neuronal cells-astrocytes and oligodendrocytes.

Epithelial stem cells in the lining of the digestive tract occur in deep crypts and give rise to several cell types: absorptive cells, goblet cells, Paneth cells, and enteroendocrine cells.

Skin stem cells occur in the basal layer of the epidermis and at the base of hair follicles. The epidermal stem cells give rise to keratinocytes, which migrate to the surface of the skin and form a protective layer. The follicular stem cells can give rise to both the hair follicle and to the epidermis.

Transdifferentiation. A number of experiments have reported that certain adult stem cell types can differentiate into cell types seen in organs or tissues other than those expected from the cells' predicted lineage (i.e., brain stem cells that differentiate into blood cells or blood-forming cells that differentiate into cardiac muscle cells, and so forth). This reported phenomenon is called transdifferentiation.

Although isolated instances of transdifferentiation have been observed in some vertebrate species, whether this phenomenon actually occurs in humans is under debate by the scientific community. Instead of transdifferentiation, the observed instances may involve fusion of a donor cell with a recipient cell. Another possibility is that transplanted stem cells are secreting factors that encourage the recipient's own stem cells to begin the repair process. Even when transdifferentiation has been detected, only a very small percentage of cells undergo the process.

In a variation of transdifferentiation experiments, scientists have recently demonstrated that certain adult cell types can be "reprogrammed" into other cell types in vivo using a well-controlled process of genetic modification (see Section VI for a discussion of the principles of reprogramming). This strategy may offer a way to reprogram available cells into other cell types that have been lost or damaged due to disease. For example, one recent experiment shows how pancreatic beta cells, the insulin-producing cells that are lost or damaged in diabetes, could possibly be created by reprogramming other pancreatic cells. By "re-starting" expression of three critical beta cell genes in differentiated adult pancreatic exocrine cells, researchers were able to create beta cell-like cells that can secrete insulin. The reprogrammed cells were similar to beta cells in appearance, size, and shape; expressed genes characteristic of beta cells; and were able to partially restore blood sugar regulation in mice whose own beta cells had been chemically destroyed. While not transdifferentiation by definition, this method for reprogramming adult cells may be used as a model for directly reprogramming other adult cell types.

In addition to reprogramming cells to become a specific cell type, it is now possible to reprogram adult somatic cells to become like embryonic stem cells ( induced pluripotent stem cells, iPSCs) through the introduction of embryonic genes. Thus, a source of cells can be generated that are specific to the donor, thereby increasing the chance of compatibility if such cells were to be used for tissue regeneration. However, like embryonic stem cells, determination of the methods by which iPSCs can be completely and reproducibly committed to appropriate cell lineages is still under investigation.

D. What are the key questions about adult stem cells?

Many important questions about adult stem cells remain to be answered. They include:

How many kinds of adult stem cells exist, and in which tissues do they exist?

How do adult stem cells evolve during development and how are they maintained in the adult? Are they "leftover" embryonic stem cells, or do they arise in some other way?

Why do stem cells remain in an undifferentiated state when all the cells around them have differentiated? What are the characteristics of their "niche" that controls their behavior?

Do adult stem cells have the capacity to transdifferentiate, and is it possible to control this process to improve its reliability and efficiency?

If the beneficial effect of adult stem cell transplantation is a trophic effect, what are the mechanisms? Is donor cell-recipient cell contact required, secretion of factors by the donor cell, or both?

What are the factors that control adult stem cell proliferation and differentiation?

What are the factors that stimulate stem cells to relocate to sites of injury or damage, and how can this process be enhanced for better healing?

Previous | IV. What are adult stem cells? | Next

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Introduction: What are stem cells, and why are they important? What are the unique properties of all stem cells? What are embryonic stem cells? What are adult stem cells? What are the similarities and differences between embryonic and adult stem cells? What are induced pluripotent stem cells?

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They are capable of dividing and renewing themselves for long periods.

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1. Introduction: What are stem cells, and why are they important?

2. What are the unique properties of all stem cells?

3. What are embryonic stem cells?

4. What are adult stem cells?

5. What are the similarities and differences between embryonic and adult stem cells?

6. What are induced pluripotent stem cells?

7. What are the potential uses of human stem cells and the obstacles that must be overcome before these potential uses will be realized?

8. Where can I get more information?

II. What are the unique properties of all stem cells?

Stem cells differ from other kinds of cells in the body. All stem cells-regardless of their source-have three general properties: they are capable of dividing and renewing themselves for long periods; they are unspecialized; and they can give rise to specialized cell types.

Stem cells are capable of dividing and renewing themselves for long periods. Unlike muscle cells, blood cells, or nerve cells-which do not normally replicate themselves-stem cells may replicate many times, or proliferate. A starting population of stem cells that proliferates for many months in the laboratory can yield millions of cells. If the resulting cells continue to be unspecialized, like the parent stem cells, the cells are said to be capable of long-term self-renewal.

Scientists are trying to understand two fundamental properties of stem cells that relate to their long-term self-renewal:

1. Why can embryonic stem cells proliferate for a year or more in the laboratory without differentiating, but most adult stem cells cannot; and

2. What are the factors in living organisms that normally regulate stem cell proliferation and self-renewal?

Discovering the answers to these questions may make it possible to understand how cell proliferation is regulated during normal embryonic development or during the abnormal cell division that leads to cancer. Such information would also enable scientists to grow embryonic and non-embryonic stem cells more efficiently in the laboratory.

The specific factors and conditions that allow stem cells to remain unspecialized are of great interest to scientists. It has taken scientists many years of trial and error to learn to derive and maintain stem cells in the laboratory without them spontaneously differentiating into specific cell types. For example, it took two decades to learn how to grow human embryonic stem cells in the laboratory following the development of conditions for growing mouse stem cells. Likewise, scientists must first understand the signals that enable a non-embryonic (adult) stem cell population to proliferate and remain unspecialized before they will be able to grow large numbers of unspecialized adult stem cells in the laboratory.

Stem cells are unspecialized. One of the fundamental properties of a stem cell is that it does not have any tissue-specific structures that allow it to perform specialized functions. For example, a stem cell cannot work with its neighbors to pump blood through the body (like a heart muscle cell), and it cannot carry oxygen molecules through the bloodstream (like a red blood cell). However, unspecialized stem cells can give rise to specialized cells, including heart muscle cells, blood cells, or nerve cells.

Stem cells can give rise to specialized cells. When unspecialized stem cells give rise to specialized cells, the process is called differentiation. While differentiating, the cell usually goes through several stages, becoming more specialized at each step. Scientists are just beginning to understand the signals inside and outside cells that trigger each step of the differentiation process. The internal signals are controlled by a cell's genes, which are interspersed across long strands of DNA and carry coded instructions for all cellular structures and functions. The external signals for cell differentiation include chemicals secreted by other cells, physical contact with neighboring cells, and certain molecules in the microenvironment. The interaction of signals during differentiation causes the cell's DNA to acquire epigenetic marks that restrict DNA expression in the cell and can be passed on through cell division.

Many questions about stem cell differentiation remain. For example, are the internal and external signals for cell differentiation similar for all kinds of stem cells? Can specific sets of signals be identified that promote differentiation into specific cell types? Addressing these questions may lead scientists to find new ways to control stem cell differentiation in the laboratory, thereby growing cells or tissues that can be used for specific purposes such as cell-based therapies or drug screening.

Adult stem cells typically generate the cell types of the tissue in which they reside. For example, a blood-forming adult stem cell in the bone marrow normally gives rise to the many types of blood cells. It is generally accepted that a blood-forming cell in the bone marrow-which is called a hematopoietic stem cell -cannot give rise to the cells of a very different tissue, such as nerve cells in the brain. Experiments over the last several years have purported to show that stem cells from one tissue may give rise to cell types of a completely different tissue. This remains an area of great debate within the research community. This controversy demonstrates the challenges of studying adult stem cells and suggests that additional research using adult stem cells is necessary to understand their full potential as future therapies.

Previous | II. What are the unique properties of all stem cells? | Next

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Introduction: What are stem cells, and why are they important? What are the unique properties of all stem cells? What are embryonic stem cells? What are adult stem cells? What are the similarities and differences between embryonic and adult stem cells? What are induced pluripotent stem cells?

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Embryonic stem cells are pluripotent which means they can turn into anything. Embryonic stem cells are taken from the inner cell mass of the blastocyst and they can be formed 3-5 days after the egg is fertilized by a sperm.

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Stem Cell injections range from $2,000-$20,000 depending on where the injection site is.

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Robert Vondracek has had multiple sclerosis for 20 years. His speech is starting to slur and he's been having more trouble getting around, and when he heard about a controversial stem cell therapy that might help, he got excited.

"I heard about the stem cell treatments being done right here in Phoenix," said Vondracek, 61. "It shocked me because it was not approved in this country, I didn't think."

The therapy was offered by an Arizona plastic surgeon who gives the stem cell treatments in the same clinic where he does cosmetic procedures.

But when Vondracek's neurologist heard about his interest in the therapy, which would cost $7,000 per treatment, "He went crazy," said Vondracek. He strongly advised Vondracek against it.

Plastic surgeons, other doctors and naturopaths at more than 100 clinics round the country are charging thousands of dollars for a controversial procedure called stem cell therapy to treat a range of disorders, including neurological diseases like MS and Parkinson's.

The procedure has angered many neurologists and prominent researchers who say these doctors are preying on vulnerable people and capitalizing on the huge but still unrealized potential of stem cell research, which they say is years away from producing an approved treatment for neurological diseases.

"Peddling snake oil in the guise of stem cell therapies is really a threat to legitimate research," said Dr. George Daley, director of the Stem Cell Transplantation Program at Boston Children's Hospital, past president of the International Society for Stem Cell Research and a professor at Harvard Medical School.

"Finding cures is hard, it takes sometimes decades, it's extremely expensive and it's not something that we can just wish and hope for," he said. "It can only be achieved through very, very hard work."

The stem cell therapy usually involves using liposuction to extract a patient's fat before separating out the stem cells using a centrifuge. The stem cells are then injected into the patient's blood stream the same day intravenously. Prices for this and similar treatments range from $6,000 to $20,000 per session.

The treatments have been popular in Europe and Asia for years, but until recently were unavailable in this country. But in the past few years, stem cell therapy clinics have cropped up in the U.S., and their numbers are increasing due to the franchise-like expansion of groups like the California-based Cell Surgical Network.

"We are growing," said Dr. Mark Berman, a Beverly Hills plastic surgeon who was one of the Cell Surgical Network's founders. He said he trained two doctors to perform the procedure just this week.

Dr. Steven Gitt , the Phoenix plastic surgeon whose services Robert Vondracek ultimately decided not to use, is also a member of the Cell Surgical Network. Gitt says he makes certain to tell his patients the procedure is not a cure and informs them they are participating in a study.

"We're doing it ethically and honestly. We are gathering good data and we are contributing and we are helping," said Gitt in a recent interview with NBC News. He stressed that the procedure is safe and he knows of no patient who has been injured by it.

Gitt said that 60 to 80 percent of the people who receive the treatment have a positive outcome, meaning their quality of life is improved. When asked for neurological patients who had a positive outcome to interview, he suggested NBC News speak with Libby Aira, whose 41-year-old daughter Darian was hit by a car and suffered a traumatic brain injury eight years ago. Darian is unable to communicate.

"We did the stem cells and just a few hours later she reached for a glass of water on the right side, her affected side," said Libby. "She couldn't grasp or hold it, but just that intention of reaching for it was something we hadn't seen."

"Since then we've seen very slow little things. No big major steps -- I want her walking -- but now I see that happening [in the future]," said Libby.

But the neurologist who dissuaded Robert Vondracek from receiving stem cell treatment accused doctors who offer the treatments with "lining their pockets."

"The only people who are benefitting are the clinics," said Dr. Virgil DiBiase. He said that dozens of patients have called him about the treatments, which they find advertised on-line, and that the costs they cited sometimes topped $15,000. "Legitimate treatments are not marketed through YouTube or slick websites."

"What's a plastic surgeon doing treating a neurological disease?" he asked.

Dr. Daley, director of the stem cell program in Boston, said it was "dramatically premature" to charge patients "for a therapy we don't yet know is safe or effective."

"I'm concerned that this this may actually be the pedaling of unproven treatments but masquerading as research," said Daley.

"Our ability to know whether any of these interventions would work in actual MS patients is going to require rigorous clinical trials and a lot more hard work," he said.

Dr. Gitt said he is performing the procedure to help his patients, and that he makes 90 percent or more of his income from his plastic surgery practice.

"What really excited and has continued to excite me about this field is that I kind of feel a little bit more like an old time real doc in that I'm really making amazing changes for people," said Gitt.

Gitt said that he and other doctors using the technique are conducting a pilot study "to identify those conditions which will merit more vigorous prospective double-blind randomized type studies and go from there." He said pharmaceutical companies and universities are not funding the procedure and that is why patients have to fund the study themselves.

Berman said the research scientists who are critical of the procedure are missing the forest for the trees.

"We are finding out stuff those guys will never find out because they're stuck in the lab," said Dr. Berman, who provided a handful of stories of people who have dramatically improved after the treatment.

He also countered critics who challenge the ethics of using a treatment that has not been sanctioned by federal regulators, or charging patients to participate in a study.

"We're not flying under the radar and I'm not apologizing to anyone," he said. "We're doing investigative work. We have a huge online database. And we're learning as we go along."

Berman said his patients all know they're part of an "investigative study" and "everybody signs informed consent." He plans to apply for something called an Investigational Device Exemption from the federal Food and Drug Administration.

Under FDA guidelines, the procedure used by Berman and Gitt is not regulated because the cells are "minimally manipulated," aren't combined with other genetic material and the patient gets only his or her cells re-injected.

According to the FDA, the value of stem cells for most new applications is largely unproven, which can mean that patients forego effective therapies and instead are treated with unproven stem cell therapies.

"The safety of stem cell therapies for a variety of uses has not been assessed," said a spokesperson for the agency. "Even stem cells isolated from a person's own tissue can present ... risks when put into an area where they are not performing the same biological function that they were originally."
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The agency said it is committed to supporting the development of new products to address unmet medical needs, including new applications for stem cell-based products. "It is important to understand that while the FDA works to make lifesaving treatments available to patients quickly and efficiently," said the spokesperson, "the FDA is committed to assuring both the safety and the efficacy of the products it approves for use in the United States."

"The FDA is concerned that the hope that patients have for cures which are not yet available may leave them vulnerable to unscrupulous providers of stem cell treatments which have not been evaluated for safety and efficacy and could potentially be harmful."

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Costly, Unproven Stem Cell Therapy for Neurological Disorders Questioned

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Robert Vondracek has had multiple sclerosis for 20 years. His speech is starting to slur and he's been having more trouble getting around, and when he heard about a controversial stem cell therapy that might help, he got excited. "I heard about the stem cell treatments being done right here in Phoenix," said Vondracek, 61.

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Scientists are developing stem cells that can be used to repair issues in the Hypothalamic cells of the brain

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Collaborating with scientists from New York, Toronto, and Tokyo, Harvard Stem Cell Institute (HSCI) researchers have devised two methods for using stem cells to generate the type of neurons that help regulate behavioral and basic physiological functions in the human body, such as obesity and hypertension, as well as sleep, mood, and some social disorders.

The work by Florian Merkle, Kevin Eggan, Alex Schier, and colleagues provides researchers, for the first time, with live hypothalamic neurons to use as targets for drug discovery and therapeutic cell-transplantation efforts for conditions related to stress, reproduction, puberty, and immune function, as hypothalamic neurons are often involved in those diseases as well.

"Not only is this exciting because of the science involved," said Merkle, a postdoctoral fellow in the lab of HSCI principal faculty member Kevin Eggan, who pioneered disease in a dish technology, "but by being able to produce this one type of neuron we bring possible treatments for a wide range of conditions closer to the clinic.

"The hypothalamus is an ancient structure of the brain," said Merkle. "It's very conserved, and that's because it plays such a basic function." Though it makes up only about 0.3 percent of the adult human brain, the hypothalamus serves as a regulator for numerous basic physiological functions.

Thus far, research exploring the origin or process of hypothalamic dysfunction has been limited because researchers haven't been able to observe live hypothalamic cells.

Merkle and a team of scientists from HSCI, New York's Sloan Kettering Institute for Cancer Research, Toronto's Hospital for Sick Children, and Japan's RIKEN developed the two neuron-generating methods, "self-patterning" and "directed" differentiation, concurrently.

The new work has been published in the journal Development.

In his self-patterning approach, Merkle put 5,000 stem cells in a dish amid an environment conducive to survival and left them alone. Within a day, the cells would aggregate and "communicate with each other" to plan which stem cells would differentiate into which neural progenitors. The aggregate eventually differentiated into cells that, together, made a tissue-like structure similar to the hypothalamus.

When asked how the two processes differed, Merkle said that during directed differentiation the researchers "are pushing [stem] cells very strongly, guiding them toward a particular fate, and not relying on them to do it themselves." Merkle used small molecules to steer stem cell differentiation down a specific pathway.

"I think that there is definitely more opportunity to explore and refine directed differentiation to make different regions within the hypothalamus," said Merkle.

While working on their approach, Merkle and his team consulted with Rudolph Leibel and Dieter Egli of Columbia University, who were at the same time developing a directed-differentiation technique that used different chemical cues and pathways. Within the last month, they published their work in the Journal of Clinical Investigation.

"It really has not been possible to study these neurons before, and now we have an opportunity to do that," said Merkle. "A lot has been done in mouse cells, but we don't know how similar [to human cells] they really are. There could be important differences that are relevant to human disease."

The ability to create lab-grown hypothalamic neurons also creates opportunities for drug development and cell-replacement therapies.

Researchers could use these new tools to grow hypothalamic neurons from patients with a specific disease. Studying the development and death from those neurons could provide researchers with the information necessarily to understand a disease's origins.

"There is a universe of diseases out there," said Merkle. "And our ability to study them using these stem cells is fundamentally limited by our ability to make those cell types in a dish."

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Collaborating with scientists elsewhere, Harvard Stem Cell Institute researchers have devised two methods for using stem cells to generate the type of neurons that help regulate behavioral and basic physiological functions in the human body, such as obesity and hypertension, sleep, mood, and some social disorders.

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Caring Medical Regenerative Medicine Clinics

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Stem Cell Injection Treatment - Stem Cell Therapy

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Stem Cell Injection treatment, also known as Bone Marrow Prolotherapy is demonstrated to the knee, hip, and ankle in this video, by Ross Hauser, MD. Caring Medical specializes in various Regenerative Injection Treatments, also known as Prolotherapy and Stem Cell therapy, for chronic pain, arthritis treatment, and sports injuries.