In November of last year, researchers in Wisconsin and Japan announced that they had successfully transformed regular adult cells into the equivalent of embryonic stem cells without the need for embryos. The advance (involving so-called induced pluripotent stem cells or iPS cells) pointed to a potential path around the moral and political debate over embryonic stem cell research, but some advocates argued that because the technique relied on retroviruses, which might be connected to some risks of cancer, they might not be safe for clinical use.

Today in the journal Science, a group of Harvard researchers reports successfully reprogramming adult cells into the equivalent of embryonic stem cells without the need for such retroviruses, and so without the cancer risk. As the Washington Post describes it:

Like iPS cells produced using retroviruses, tests showed that the cells were indistinguishable from embryonic stem cells and could be transformed into any type of tissue, including lung, brain, heart and muscle, without producing cancerous tumors.

The work was done in mice, but the researchers seem confident that, as with earlier iPS cell work, it will be readily reproducible in humans. “There’s no reason to believe it would not work,” the team’s leader told the Post.

More then ever, it appears that the promise of such pluripotent cells can be explored—all the way from basic science to the clinic—without the need to use or destroy human embryos, and so without political or ethical controversy. As President Bush put it back in 2006, in defending his approach to the issue and describing the iPS technique (which was then still largely theoretical), science and ethics need not be at odds; with the right policies and the right scientific techniques, they can be championed together. Here’s hoping.