3 Ways That Stem Cells May Speed New Cures

Human induced pluripotent stem cells, or iPS cells

"We're quietly excited," says Douglas Melton, codirector of the Harvard Stem Cell Institute. Melton and other scientists who are trying to harness embryonic stem cells' power to turn themselves into many different types of human tissue have had to separate that work from the rest of their laboratories, with stickers marking which equipment could be used for stem cell work and which for all other work. They also couldn't collaborate with other scientists whose work was paid for by grants from the National Institutes of Health, the primary source of funding for biomedical research in the United States.

Since then, scientists have had success in using other forms of stem cells. In 2007, Rudolph Jaenisch, a researcher at the Whitehead Institute in Cambridge, Mass., created induced pluripotent stem cells (IPS cells), which can be made from cells taken from an adult and appear to have the same regenerative power as embryonic stem cells. Last year, Jaenisch used IPS cells to treat sickle cell anemia and Parkinson's in rodents.

If IPS cells work in humans, they could eliminate one of the biggest problems with embryonic stem cell therapy: Patients need to take immune-suppressing drugs, so that their bodies won't reject and attack the cells as foreign. In the Geron trial, patients will take low-level immune-suppressing drugs for six months. Adult stem cells also have been used to grow organs, including bladders, of the same type of cells. That way, they don't need to differentiate into the right kind of cell, as embryonic cells do.

"We look forward to everyone seeing that we want to do this research in an ethical way," says Harvard's Melton, who is working with stem cells to create pancreatic beta cells, which could be injected into patients with type 1 diabetes to replace cells destroyed by the immune system. "No one should think that because the restrictions might be lifted in January, that cure will be available this summer, or even years from now. These cures take years of research. But if they take years of research, why not start now?"