miRNA expressions in non-cancerous and cancerous human gastric tissues

We investigated the involvement of microRNAs (miRNAs) in gastric cancers. MiRNA expression was profiled from 40 cancerous and 40 non-cancerous tissues obtained from the National Cancer Centre, Singapore, and Singhealth Tissue Repository, Singapore. We identified 80 differentially expressed miRNAs in tumors compared with normal tissues. Among these miRNAs, we identified hsa-mir-486-5p (mir-486) as a significantly downregulated miRNA in GC. Subsequent functional characterization revealed that mir-486 playing a tumor suppressor role. We also observed frequent genomic deletion of mir-486 in 20-30% of GCs. To our knowledge, mir-486 represents one of the first tumor suppressor miRNAs in GC inactivated through genomic deletion. MiRNA expression was profiled on Agilent Human miRNA Microarrays (V2) representing 723 human and 76 human viral miRNAs in 40 normal and 40 cancerous gastric tissues.