Reprogrammed Stem Cells Are Rife with Mutations

Adult cells that have been reprogrammed into stem cells harbor a number of genetic mutations, some of which appear in genes that have been linked to cancer. While scientists don't yet know how this might affect the use of the cells in medicine, they say the findings show that the cells need to be studied much more extensively.

"As we think about using [these] cells for therapy, we will want to consider what kinds of screening tests we want to do," says Lawrence Goldstein, a professor of molecular biology at the University of California, San Diego. One of the major concerns about stem-cell-based therapies has been whether they carry a risk of cancer; both stem cells and cancer cells are distinguished by their ability to continually divide.

In two studies published today in Nature, researchers analyzed the genome of induced pluripotent stem (iPS) cells, adult cells that have been genetically or chemically reverted to the stem cell state. These cells have attracted intense interest from both scientists and the public as a potential alternative to embryonic stem cells. Like...