Scientists are using cyanide to attack tumours.
They have tested a two-stage drug that harnesses the power of the dangerous chemical to kill bowel cancer cells in the lab.
The researchers, at Imperial College, London, now hope to refine the technology and test it on patients.
The technique takes a lead from some plants that release cyanide to protect themselves from insect attack.
The cassava plant, almond tree and hydrangea, all have an enzyme that will produce cyanide when it comes into contact with a particular sugar molecule.
The enzyme and the sugar are normally kept apart and are only brought together when a pest bites into the plant tissue.
The Imperial College scientists have engineered the enzyme and attached it to an antibody that will target specific tumours, when injected into the body.
A second drug, containing the sugar, would then be introduced which would react with the enzyme to release cyanide and kill the cancer cells.
Dr Mahendra Deonarain said the system would be so specific that only the target tumour would be exposed to the cyanide.
“The enzyme will circulate around the body and accumulate in the tumour only, and then it will clear from everywhere else. Then the second step is to inject the sugar drug and that itself will circulate around the body but only where the tumour is, where the enzyme is, will you get the cyanide.
“It will be enough to kill the cancer cells and you will be able to repeat it over and over again until the tumour has gone.”
Dr Deonarain said the cancer cells would not be able to develop resistance to the cyanide in the way they can with some of current cancer therapies.