Question: What are stem cells?
Answer: Stem cells have the potential to develop into different cell types in the body. A repair system for the body, they can theoretically divide without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell could either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell or a brain cell.
Q: Why are doctors and scientists so excited about them?
A: By studying how stem cells transform into specialized cells, researchers can gain insight into cancer, birth defects and other disorders. Stem cells could also become a renewable source of replacement cells and tissues that could be used to treat a range of diseases and conditions, such as heart disease, stroke, diabetes, spinal cord injury, Parkinson’s disease, Alzheimer’s and arthritis.
Q: What’s the difference between an embryonic stem cell and an adult stem cell?
A: Embryonic stem cells are isolated from embryos only a few days old and have been used to create stem cell “lines,” or cultures that can be grown indefinitely in the laboratory and distributed to researchers. Embryonic stem cells have the potential to develop into any type of cell in the body.
Adult stem cells are taken from body parts such as bone marrow. Thus far, adult stem cells haven’t proven to be able to change into every kind of cell. An adult stem cell in the brain, for example, can become a Neuron but not a liver cell.
Q: What is a very small embryonic-like stem cell – or VSEL?
A: VSELs are rare stem cells found in adult bone marrow that have the characteristics of embryonic stem cells in terms of their potential to develop into any type of cell in the body.
Dr. Mariusz Ratajczak, director of the stem cell biology program at the University of Louisville’s James Graham Brown Cancer Center, led a project that has grown mouse VSEL cells in a lab and has caused them to change into nerve, heart and pancreas cells.
Q: Are stem cells being used successfully to treat human diseases?
A: Yes. Blood-forming stem cells in bone marrow are routinely used to treat disease. Doctors have been transferring these cells in bone-marrow transplants for more than 40 years, and more advanced ways of collecting these cells are being used to treat leukemia, lymphoma and several inherited blood disorders.
Q: What is the U.S. government’s policy on embryonic stem cell research?
A: Such research may receive federal funding only if the cell line used was developed before Aug. 9, 2001, and the embryo creating the line could not be developed further as a human being. The National Institutes of Health examines stem cell lines and maintains a registry of those that satisfy federal criteria.
Sources: University of Louisville James Graham Brown Cancer Center; National Institutes of Health