Cancer (1)
- Stem cells: What they are and what they do
Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
continued:
Stem cells: What they are and what they do
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. 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. That way, researchers don't have to get stem cells from an embryo itself.
What is stem cell therapy and how does it work?
Stem cell therapy is the replacement of diseased, dysfunctional or injured cells with either adult or embryonic stem cells. It's somewhat similar to the organ transplant process but uses cells instead of organs. Stem cell therapy is sometimes called regenerative medicine.
Researchers grow stem cells in the lab. These stem cells are manipulated to make them specialize into specific types of cells, such as heart muscle cells, blood cells or nerve cells. This manipulation may involve changing the material in which the stem cells are grown or even injecting genes into the cells. The specialized cells could then be implanted into a person. For example, if the person had heart disease, the cells could be injected into the heart muscle. The healthy, transplanted heart cells could then contribute to repairing defective heart muscle.
Have stem cells already been used to treat diseases?
Yes, stem cell transplants, also known as bone marrow transplants, have been performed in the United States since the late 1960s. These transplants use adult stem cells.
Adult stem cells are being tested in other applications, including a number of degenerative diseases, such as heart failure. Stem cells from umbilical cord blood have been successfully used in clinical trials to treat rare genetic diseases.
Therapies using embryonic stem cells aren't yet ready to treat diseases in people.
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, for instance, don't want to transplant a stem cell into a person hoping it'll become a heart cell only to learn that it's become a bone cell, with potentially dangerous consequences. Researchers have found ways to direct stem cells to become specific types of cells, and research into this area has advanced significantly.
Embryonic stem cells could also become tumor cells — something that's happened in animal experiments — or travel to a part of the body where they're not intended to go. They 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 have found ways to avoid these complications and continue studying ways to control stem cells. They are also studying alternatives.
What is therapeutic cloning and what benefits might it offer?
Therapeutic cloning 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 creates a line of stem cells that is genetically identical to the donor's — in essence, a clone. This technique is also called somatic cell nuclear transfer.
Some researchers believe that stem cells derived from therapeutic cloning may offer benefits over those from fertilized eggs because they're less likely to be rejected once transplanted back into the donor, and they 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, such as sheep.
What does the future hold for stem cell therapy?
Researchers say the field has promise. Stem cell transplants using adult stem cells continue to be refined and improved. And researchers are discovering that adult stem cells may be somewhat more versatile than originally thought, which means they may be able to treat a wider variety of diseases. Studies using embryonic stem cells or embryonic-like stem cells to regenerate tissue and organs in people are just getting started. Researchers are enthusiastic about the potential for regenerative medicine treatments.
Previous page(2 of 2)
