MicroRNA expression signature in gastric cancer

Objective: To identify the miRNA specific signature as novel diagnostic and prognostic tools for gastric cancer. Methods: miRNAs expression profiling of 3 normal gastric tissues, 24 malignant tissues, gastric cancer cell SGC7901 and normal gastric cell GES-1 were detected using microarray technology. The hierarchical clustering algorithm of the Cluster software was used to analyse the miRNAs expression of all samples. The expression levels of miR-433 and miR-9 which were significantly down-regulated in gastric cancer tissues and SGC7901 cells by microarray technology were validated by quantitative Real-time PCR (qRT-PCR).Results: Differential expressions of 26 individual miRNAs between normal samples (including 3 normal gastric tissues and GES-1 cells) and carcinomas (including 24 malignant tissues and SGC7901 cells) were discovered,19 of them showing down-regulation and 7 up-regulation in carcinoma samples. Hierarchical clustering of the cancer samples by their miRNA expression accurately separated the carcinomas from normal samples and further their histotypes of carcinomas. The expression levels of miR-433 and miR-9 were significantly down-regulated in gastric cancer tissues and SGC7901cells Conclusion: The differential expression of miR-433 and miR-9 may be used as a novel diagnostic tool for gastric cancer.