A great deal of stem cell research focuses on new ways to make and use pluripotent stem cells that can be created by reactivating embryonic genes to 'reprogram' mature adult cells. Scientists have discovered a new kind of stem cell - induced XEN cells, or iXEN - one that could lead to advances in regenerative medicine as well as offer new ways to study birth defects and other reproductive problems.
"Other scientists may have seen these cells before, but they were considered to be defective, or cancer-like," said study lead author Tony Parenti from Michigan State University in the US. "Rather than ignore these cells that have been mislabeled as waste byproducts, we found gold in the garbage."
The findings were reported in the Stem Cell Reports.
Parenti and his team speculated that if the embryo produces both pluripotent and XEN cells, this might also occur during reprogramming. The eureka moment came when Parenti discovered colonies of iXEN cells popping up like weeds in his iPS cell cultures.
Using mice models, the team spent six months proving that these genetic weeds are not cancer-like, as previously suspected, but in fact, a new kind of stem cell with desirable properties.
Even more surprising, the team found that by inhibiting expression of XEN genes during reprogramming, they could decrease production of iXEN cells and increase production of iPS cells.
The next steps of this research will involve seeing if this process occurs in human cells.