Micrograph of an oligodendroglioma, a type of brain cancer. Credit: Nephron

Researchers in the U.S. have found a way to turn stem cells into an effective weapon against brain tumors by loading stem cells with a specific toxin.

The idea of using stem cells to kill cancer cells is certainly not new, but so far the idea has been problematic due to a risk of not only killing the cancer cells but also healthy cells surrounding the tumors.

The toxin used to kill the cancer cells is called Cytotoxins and is deadly to all cells. But the researchers have learned to tag toxins in such a way that they can only enter cancer cells and not other cells, using some specific surface molecules. Thereby making it possible to get a toxin into a cancer cell without posing a risk any other cells.

The team of researchers at Harvard Medical School have successfully manage the previously impossible. The research team first surgically removed the brain tumors then they injected mice with engineered stem cells. These stem cells have been loaded with Cytotoxins that effectively knocks out the remaining cancer cells – cancer cells which would otherwise have led to tumor regrowth.

The researchers developed a biodegradable gel for which they embedded the stem cells before being injected into the mice. And this gel composition is what makes the stem cells able to kill the cancer cells without harming the surrounding healthy cells.

The method has so far only been tested on mice, but the researchers are now hopeful that it can be used on people in the future. Clinical trials on humans will possibly begin within five years.

The study Engineering toxin-resistant therapeutic stem cells to treat brain tumors, published in the journal Stem Cells, was done by scientists from both the Harvard Stem Cell Institute and the Massachusetts General Hospital.

Engineering toxin-resistant therapeutic stem cells to treat brain tumors