The Human Being Re-Invented!
In a surprising advance that could sidestep the ethical debates surrounding stem cell biology, researchers have come much closer to a major goal of regenerative medicine, the conversion of a patient’s cells into specialized tissues that might replace those lost to disease. The advance is an easy-to-use technique for reprogramming a skin cell of a mouse back to the embryonic state. Embryonic cells can be induced in the laboratory to develop into many of the body’s major tissues.
If the technique can be adapted to human cells, researchers could use a patient’s skin cells to generate new heart, liver or kidney cells that might be transplantable and would not be rejected by the patient’s immune system. But scientists say they cannot predict when they can overcome the considerable problems in adapting the method to human cells. The technique, if adaptable to human cells, is much easier to apply than nuclear transfer, would not involve the expensive and controversial use of human eggs, and should avoid all or almost all of the ethical criticism directed at the use of embryonic stem cells.
“From the point of view of moving biomedicine and regenerative medicine faster, this is about as big a deal as you could imagine,” said Irving Weissman, a leading stem cell biologist at Stanford University, who was not involved in the new research.
David Scadden, a stem cell biologist at the Harvard Medical School, said the finding that cells could be reprogrammed with simple biochemical techniques “is truly extraordinary and frankly something most assumed would take a decade to work out.”
Beyond that is the hope of generating cells for therapy. Researchers have learned how to make embryonic cells in the laboratory develop into neurons, heart muscle cells and other tissues. In principle, these might be injected into a patient to replace or supplement the cells of the diseased tissue, without fear of immune rejection. Still, repairing the body with its own cells should in principle be a superior form of medicine to the surgeon’s knife and the oncologists’ poisons. But the first fruit of the new technique will be in figuring out how cells work.
This and other methods will lead to an explosion of information that will “open the door for understanding how cells program and re-program their fate,” Dr. Scadden predicted. If and when applicable to human cells, he said, the four-gene approach “will have profound implications for new biology, regenerative medicine and will change the ethical debate around stem cells.”