By Jonny Lupsha, Current Events Writer
Scientists have grown a mouse embryo, including a beating heart, in a Petri dish. Earlier attempts lacked the full variety of tissues and cell types found in naturally grown embryos. Stem cell technology has been developing rapidly.
Humanity has yet to develop fully functioning organs in a lab, but science took a large step toward that goal, recently. A mouse embryo that includes a beating heart has been grown from stem cells in a Petri dish. The embryo in question won’t grow to be a living mouse, since it lacks other major organs like a brain. However, it marks considerable progress toward producing functional replacement organs for humans in a dish, without the need for transplants from another human.
Stem cell technology continues to progress at a rapid pace. In his video series Understanding Genetics: DNA, Genes, and Their Real-World Applications, Dr. David Sadava, Adjunct Professor of Cancer Cell Biology at the City of Hope Medical Center, explained why.
Trouble with Transplants
“There is a need for new cells in medicine to replace cells that are damaged,” Dr. Sadava said. “For example, in a heart attack, the heart muscle is damaged; there’s often permanent damage to the heart muscle. In the brain, Parkinson’s disease and other diseases result from a lack of functional cells.”
According to Dr. Sadava, in diabetes—especially type 1 diabetes—the pancreas is damaged. The pancreas produces insulin, and if it’s damaged it can’t produce it, and its insulin must be replaced from another source. Finally, muscles in the musculoskeletal system tear or break and must be repaired. In summary, there are many types of organ damage, resulting in many people on waiting lists for organ transplants while there are limited sources of organ donation.
“The second problem relating to transplanting organs is that the immune system ultimately will reject the transplant as non-self,” Dr. Sadava said. “A person who gets an organ transplant has to take immunosuppressive drugs to keep that organ there as long as possible.”
Stem cell transplants, on the other hand, can replace failing cells and pass the immune system’s rigorous inspections. And they already happen every day.
Stem Cells ‘R Us
When a patient undergoes cancer radiation therapy and chemotherapy, their bone marrow is damaged. This includes all dividing cells, including stem cells, inside the bone marrow. When this happens, the patient becomes severely anemic and very immunocompromised. They stop producing red blood cells and only produce very limited white blood cells.
“If the patient’s bone marrow is removed before therapy and stored, literally, in a refrigerator, this bone marrow has enough stem cells to form the new blood cells when they are returned after therapy,” Dr. Sadava said. “These stem cells are called pluripotent—they can give rise to all the red and white blood cells.”
According to Dr. Sadava, bone marrow also contains other stem cells. These other stem cells don’t form blood but they form the tissues around the blood, such as blood vessels, muscle, and bone.
Stem cells are already being used in medicine. Scientists regularly make new strides in developing them to replace our own failing cells.