Cancer of the oesophagus, or food pipe/gullet, is an aggressive disease with a poor outlook. The majority of patients with this disease receive treatment with radiation, termed radiotherapy, to shrink their tumours prior surgery. Unfortunately, only approximately 30% of patients tumours have a good response to radiation, with the remaining majority resistant to treatment. In this project a number of naturally-occuring molecules, called microRNAs, which have been found to be lost from oesophageal tumours that are resistant to treatment, will be tested to determine if they can increase the sensitivity of oesophageal tumour cells to radiation. If this is the case then synthetic microRNAs could potentially be used like a drug to enhance the sensitivity of patient tumours to radiotherapy.