5 November 2012 New type of molecular switch could turn up the volume on bowel cancer treatment A new type of molecular switch can boost common chemotherapy drugs to destroy bowel cancer cells, according to research presented today (Monday) at the NCRI Cancer Conference in Liverpool. Scientists at the University of Dundee examined hundreds of molecules which may help to predict whether bowel cancer patients can be successfully treated with chemotherapy. Many bowel cancer patients are treated with a drug called 5-fluorouracil, or 5-FU, but not all patients respond well. It is difficult to predict which patients will be successfully treated. The team revealed in laboratory experiments that blocking a molecular switch 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 K-RAS are found in one third of bowel cancers, particularly in fast-growing cancers with poor survival. The research showed that common drugs, 5-FU and oxaliplatin, 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**. Lead author, Dr Gillian Smith, at the University of Dundee, said: "Our research reveals that changing the behaviour of K-RAS boosts the effect of certain drugs to kill bowel cancer cells. "This research is at an early stage, but if we're able to prove these results in larger studies, the findings could provide new scope for bowel cancer treatments targeting the K-RAS gene. Our findings are particularly interesting because there is already a test available in the clinic that can identify which patients have a faulty version of K-RAS." Bowel cancer is one of the most commonly diagnosed cancers in the UK with more than 41,000 people diagnosed with the disease in the UK each year. Dr Jane Cope, director of the NCRI, said: "This is exciting research that adds to the dramatic progress made over the past thirty years in tackling bowel cancer. "People diagnosed today are twice as likely to survive for at least ten years as those diagnosed in the 1970s and we hope that these findings will one day help scientists develop better ways to treat and monitor the disease in the future - ultimately increasing survival from cancer." For media enquiries please contact Emma Rigby in the NCRI press office on 0151 239 6043 / 6044 / 6045 or, out-of-hours, the duty press officer on 07050 264 059. Notes to editors: *Micro RNA (miRNAs) are small non-coding RNAs which act as negative regulators of gene expression.

**Fluorouracil (5-FU) and Oxaliplatin kill cells by blocking cell replication. The drugs are incorporated into DNA, preventing DNA being made properly. When cells divide more quickly they synthesize DNA more quickly and incorporate more 5FU and Oxaliplatin than healthy cells - causing them to be more sensitive to the drug. About the NCRI Cancer Conference

The National Cancer Research Institute (NCRI) Cancer Conference is the UK's major forum for showcasing the best British and international cancer research. The Conference offers unique opportunities for networking and sharing knowledge by bringing together world-leading experts from all cancer research disciplines. The eighth annual NCRI Cancer Conference is taking place from 4-7 November 2012 at the BT Convention Centre in Liverpool. For more information visit www.ncri.org.uk/ncriconference Follow the NCRI on Twitter: https://twitter.com/NCRI #NCRI2012 About the NCRI

The National Cancer Research Institute (NCRI) was established in April 2001. It is a UK-wide partnership between the government, charity and industry which promotes co-operation in cancer research among the 22 member organisations for the benefit of patients, the public and the scientific community. For more information visit www.ncri.org.uk NCRI members are: the Association of the British Pharmaceutical Industry (ABPI); Association for International Cancer Research; Biotechnology and Biological Sciences Research Council; Breakthrough Breast Cancer; Breast Cancer Campaign; Cancer Research UK; CHILDREN with CANCER UK; Department of Health; Economic and Social Research Council; Leukaemia & Lymphoma Research; Ludwig Institute for Cancer Research; Macmillan Cancer Support; Marie Curie Cancer Care; Medical Research Council; Northern Ireland Health and Social Care (Research & Development Office); Prostate Cancer UK; Roy Castle Lung Cancer Foundation; Scottish Government Health Directorates (Chief Scientist Office); Tenovus; The Wellcome Trust; Welsh Government (National Institute for Social Care and Health Research); and Yorkshire Cancer Research. About the University of Dundee

The University of Dundee is internationally recognised for its excellence in life sciences and medical research. The University has a top-rated medical school with research expanding from "the cell to the clinic to the community". Dundee was voted best in the UK for student experience in the 2012 Times Higher Education Student Experience Survey. See www.dundee.ac.uk for further details.

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