Development of microRNA expression signatures for gastric cancer

To further investigate of microRNA expression profile of gastric cancer, we have employed whole microRNA gene chip as a discovery platform to identify gene differential expression between gastric cancer tissues with mormal gastric tissues.Expression of four microRNAs (miR-125b,miR-451,miR-192b,miR-200b) from this signature was quantified and verified in the same RNA samples by real-time PCR. A total of 4 consecutive patients with gastric cancer undergoing elective surgery were entered into this study. After obtaining informed consent from the patients and after receiving the approval of the ethics committee, the following tissue samples were collected: tumor (3 × 3 × 5 mm) and adjacent normal tissues (3 × 3 × 5 mm).