Published in the journal Stem Cells, this study was the work of scientists from Massachusetts General Hospital and the Harvard Stem Cell Institute. Stem cells were engineered genetically to produce and secrete toxins which kill brain tumours in experiments on mice, without killing normal cells or themselves. To test the procedure in humans is its next stage. They had been researching a stem-cell-based therapy for cancer, which would kill only tumour cells and no others for many years. They used genetic engineering to make stem cells that spewed out cancer-killing toxins, however, they were also able to resist the effects of the poison they produced. Moreover, they posed no risk to normal and healthy cells. The stem cells were surrounded in gel and placed at the site of the brain tumour in animal tests after it had been removed. Their cancer cells then died because of no defense against the toxins.

Toxin-producing stem cells which are in blue color help kill brain tumour cells in the tumour cavity in green color. lead author and director of the molecular neurotherapy and imaging lab said the results were very positive. He also said that cancer-killing toxins have been used with great success in the variety of blood cancers, but they don’t work as well in solid tumours because the cancers aren’t as accessible and the toxins have a short half-life. It shows you can attack solid tumours by putting mini pharmacies inside the patient which deliver the toxic payload direct to the tumour. But so far the technique has only been tested in mice and on cancer cells in the lab, so much more work will need to be done before scientists will know if it could help patients with brain tumours. She said this type of research could help boost survival rates and bring much-needed progress for brain cancers with the hopes that therapies could be used in clinical trials within the next five years.