Scientists have figured out a way to make skin cells attack brain tumors. A report on their progress has been published in the journal Science Translational Medicine.

We have stem cells all over our bodies, including in our skin, and they come in lots of different varieties. You may have heard of pluripotent stem cells, which can, as their name suggests, grow into just about any body part. Then there are neural stem cells (NSCs), which develop into nerve and brain cells.

Glioblastoma is the most common type of primary brain tumor. They’re fast and fierce; after diagnosis, the average survival rate is only 12 to 15 months. But they also have a built-in vulnerability: they emit a chemical that naturally attracts NSCs.

Under ordinary circumstances, this would not be a weakness. But researchers have engineered a type of NSC that works like a heat-seeking missile, carrying cancer-killing medicine straight into tumor cells. The idea is to transplant these special skin cells into people with cancer, giving their drug treatment a much better chance of success.

Early clinical trial results have been positive, but the treatment faces the same obstacle as any other transplant: our bodies do not welcome cells they don’t recognize. In fact, we outright reject them, and this rejection can make transplant patients much sicker.

To get around this issue, the authors of the new study took NSCs from the skin of the very patients they wanted to treat—in this case, laboratory mice. They were able to culture the NSCs into drug carriers in an astonishing four days. They transplanted these new microscopic drug mules back into the mice, whose bodies tolerated them well. The treatment had an incredibly high success rate, shrinking tumors and nearly doubling the rodents’ survival time.

We’ll need more research before we can try this in humans, but the initial results seem encouraging and could be used to treat a broad range of tumor types.

Editor's note: This post has been updated with the full journal name.