Using Stem Cells to Kill Brain Cancer
Researchers at the Harvard Stem Cell Institute have published a proof of concept study in which they programmed stem cells to produce a toxin that selectively kills brain cancer cells.
Khalid Shah and his team engineered stem cells to produce a cytotoxin that will shut down protein production in a cell, causing the cell to die after a few day. The cytotoxin itself is linked to a carrier that requires a specific surface molecule in order to be taken into a cell – a surface molecule found on certain brain cancer cells but not on healthy brain cells.
They further engineered these stem cells to be resistant to the cytotoxin themselves.
The result are stem cells that are essentially little factories that can produce a toxin that will kill brain cancer cells but leave healthy cells alone. The stem cells can theoretically be implanted at the site of a tumor, where they will continuously crank out the cancer-killing toxin.
“We tested these stem cells in a clinically relevant mouse model of brain cancer, where you resect the tumors and then implant the stem cells encapsulated in a gel into the resection cavity. After doing all of the molecular analysis and imaging to track the inhibition of protein synthesis within brain tumors, we do see the toxins kill the cancer cells and eventually prolonging the survival in animal models of resected brain tumors.”
This is a very hopeful step for what might become an important treatment modality for solid tumors. Shah’s team plans on further developing stem cells to secret other cancer-killing toxins. Of course, these treatments need to be tested in humans, and so if all goes well we are still likely 10 years away from seeing these treatments used in cancer patients outside of clinical trials.
The technology also demonstrates that stem cells can be used for more than just replacing lost or diseased cells. They can be engineered to serve many functions, including targeted drug delivery systems.