The Dundee University team examined hundreds of molecules which may help predict whether bowel cancer patients can be successfully treated with chemotherapy.
Bowel cancer is one of the most common cancers in the UK with more than 41,000 cases diagnosed each year. Many patients are treated with a drug called 5-fluorouracil, or 5-FU, but not all patients respond well and it is difficult to predict who will be successfully treated.
The Dundee team found that blocking a molecular switch – a molecule which can shift between two or more states – called miR-224 "tricks" bowel cancer cells containing a healthy gene called K-RAS into behaving like cells with a damaged form of the gene.
K-RAS usually controls the normal growth of healthy bowel cells but faulty versions of the gene are found in one-third of bowel cancers, particularly in fast-growing cancers.
The research showed that common drugs were more effective in treating bowel cancer cells with damaged forms of K-RAS, and bowel cancer cells with healthy K-RAS in which the miR-224 switch had been blocked.
Dr Gillian Smith, lead author of the study, said: "The findings could provide new scope for bowel cancer treatments targeting the K-RAS gene."