Stem Cell Déjà Vu

Ho Hum. Just more of the same , promising news. And—it almost goes without saying—no embryos are involved:

For the past couple years, there’s been a steady march toward making adult cells mimic embryonic stem cells. Success could ultimately defuse the debate over destroying embryos to harvest the stem cells, which have the ability to transform into any type of human cell, and which scientists think may someday be of great therapeutic benefit.

The latest step was reported today, when scientists described a new method that gave adult mouse cells the characteristics of embryonic cells. The key advance this time: They reprogrammed the cells using proteins instead of genes. That could be important, because using genes created risks of unintended genetic mutations. Here’s the paper from the symmetrically named journal Cell Stem Cell .

It’s pretty striking how steady the progress has been on this front. The first reports of using genetic techniques to reprogram adult mouse cells into embryonic stem cells came in April, 2007. The leap from mouse cells to human cells can often be a tricky one, but scientists managed the feat in human cells just months later .