What if human cells could be stimulated to regenerate body parts or repair damaged tissues in the same way that earthworms or planarians can? Embryonic stem cells are the most versatile type of cells to work with because they can differentiate into any kind of cell in the body. Adult stem cells are more tissue-specific, although the body responds better to its own stem cells in therapy. In order for stem cell therapies to work, the body’s immune system must be suppressed so there is no reaction to the transplanted cells. Additionally, scientists must take special care to ensure the cells proliferate enough to heal the body but not so much that cancer develops.
There are two types of stem cells research. One involves the use of embryonic stem cells and the other involves the use of adult stem cells. The embryonic cells come from a one-week-old mass of cells called a blastocyte. Many of the fetal stem cells come from in vitro fertilization patients who had leftovers after receiving fertility treatment. A single embryo can create enough lines of cells for use in Stem cell therapies. Tissue from aborted fetuses is not regularly used in stem cell research. What makes an embryonic stem cell so special is that it can develop into any organ or tissue. Stem cell therapies can help treat diseases like heart or Parkinson’s disease, as well as burn or stroke victims and patients with spinal cord injuries, muscular dystrophy, arthritis and diabetes.
Though fetal stem cells have been the focus of most of the research, scientists are discovering that adult stem cells are particularly effective in transplants. For instance, they can grow an entire organ, a section of the windpipe or a section of tissue to offer the human host, which will most certainly accept the new cells derived from its own DNA. Another alternative to using embryonic stem cells is under current examination. It involves stimulating adult stem cells to revert back to their “pluripotent” state, which allows them to proliferate again. It’s believed that humans may be able to regrow lost skin or repair other tissues this way, although more research is needed before human trials can begin to prove this theory.
In recent stem cell news, the Harvard Stem Cell Institute (HSCI) and Massachusetts General Hospital discovered that a medication for bone marrow cancer can affect osteoporosis in mice by acting upon mesenchymal stem cells, which differentiate into several tissue types. “Stem cell therapies are often thought of as putting new cells into the body,” said David Scadden, director of the MGH Center for Regenerative Medicine, “but this study suggests that medications can turn on existing stem cells that reside in the body’s tissues, acting as regenerative medicines to enhance the body’s own repair mechanisms.” Therefore, instead of relying on controversial embryonic stem cells, a person’s own stem cells can be used in the treatment.