LONDON, 7 August (SPIS MedWire). Cyanide could be used to attack and destroy cancer cells leaving healthy cells untouched. The research — carried out at Imperial College in London and reported at the British Association's annual meeting this week — was based on an enzyme in cassava plants that produces cyanide on contact with a specific sugar molecule; cassava plants use the mechanism to protect themselves from insect attack. In the laboratory the enzyme was combined with a tumour-specific antibody and injected into the site of the tumour. A second drug, containing the sugar molecule was then injected and reacted with the enzyme to release cyanide that killed the tumour cells. Dr Mahendra Deonarain, speaking at the BAAS meeting, pointed out that although cyanide is an effective poison, most remains near the site of the tumour and any seepage is soon degraded by the liver. Dr Deonarain said: "Current cancer treatments are often toxic, with side-effects that limit their use. Also, cancers develop resistance to the therapies. Our approach suggests a more specific, safer treatment for a disease which touches one in three people at some point in their lives."