Both Ways

It's always been thought that while stem cells can give rise to all the different cells in the human body, once they become specialized, they stay specialized. Now, a new study done by researchers at the Whitehead Institute say they can actually go both ways, and that some specialized cells can spontaneously revert back to a stem-cell state, says Not Exactly Rocket Science's Ed Yong. Researchers have spent a lot of time trying to figure out ways to artificially reprogram adult cells into their more malleable stem form, but as it turns out, cells can do that all by themselves. The Whitehead researchers found this when they observed floating cells in a flask of human breast cells, except these floaters weren't dead or dying, but were perfectly healthy, Yong says. "This ability to survive in a free-floating environment was a trait that stem cells share," he adds. After more testing, the researchers found that the cells were indeed reverting back to an earlier state. Even more surprising, they found that breast cancer cells can turn into breast cancer stem cells. "This opens up a big can of worms. Several researchers are now trying to develop treatments that target cancer stem cells. The hope is that such drugs would seek and destroy the heart of tumors, robbing them of their ability to bounce back," Yong says. "But clearly, if normal breast cancer cells can turn into cancer stem cells, then this approach has a fatal flaw — the tumors could simply regenerate their heart." This has implications for medicine as well as for researchers trying to reprogram adult cells for use as stem cells, Yong adds.