The　discovery　of　microRNAs　(miRNAs)　provided　a　new　avenue　for　early　diagnosis　and　treatment　of　GC.　MiR-137　has　been　reported　to　be　under-expressed　and　involved　in　various　cell　processes.　However,　the　role　of　miR-137　in　GC　is　less　known.　In　this　study,　we　show　that　miR-137　is　under-expressed　in　GC　and　functions　as　a　tumor　suppressor　through　targeting　Cyclooxygenase-2　(Cox-2),　which　subsequently　suppresses　the　activation　of　PI3K/AKT　signaling　pathway　both　in　vitro　and　in　vivo.　Moreover,　restored　Cox-2　expression　partially　abolished　the　tumor　suppressive　effects　of　miR-137　in　GC　cells,　suggesting　miR-137　may　suppress　GC　carcinogenesis　by　targeting　Cox-2.　(C)　2014　Federation　of　European　Biochemical　Societies.　Published　by　Elsevier　B.V.　All　rights　reserved.