title: MicroRNA-9 inhibits the gastric cancer cell proliferation by targeting TNFAIP8.
abstract: OBJECTIVE
  MicroRNA-9 is frequently dysregulated in many human carcinoma types, including gastric cancer (GC). Previous studies demonstrated that the expression of TNFAIP8 in GC is correlated with tumour occurrence, development, invasion, metastasis and prognosis. However, till now, the relationship between MicroRNA-9 and TNFAIP8 in GC has not been reported.
  
  
  METHODS
  Levels of miR-9 and TNFAIP8 expression in GC tissues and in human GC cell lines were studied using qualitative real-time PCR (qRT-PCR) and Western blotting. Cell viability was detected using the CCK-8 and clone formation assays. A dual-luciferase reporter system was used to confirm the target gene of miR-9.
  
  
  RESULTS
  We found that the expression level of MicroRNA-9 in GC tissues and cell lines was significantly lower than that in adjacent non-cancerous tissues and human immortalized gastric epithelial cell (GES) line, respectively. In addition, overexpression of MicroRNA-9 markedly inhibited GC cell proliferation in vitro and tumour growth in vivo. Further experiments revealed that TNFAIP8 was a direct and functional target of MicroRNA-9 in GC and overexpression of MicroRNA-9 obviously down-regulated the expression of TNFAIP8, which was involved in the gastric carcinogenesis and cancer progression.
  
  
  CONCLUSIONS
  Our results suggested that MicroRNA-9-TNFAIP8 might represent a promising diagnostic biomarker for GC patients and could be a potential therapeutic target in the prevention and treatment of GC.
authors.affiliation: Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical University, Xuzhou, China.
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Gao
authors.affiliation: Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical University, Xuzhou, China.
authors.forename: Fu-Chun
authors.initials: FC
authors.lastname: Huo
authors.affiliation: Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical University, Xuzhou, China.|Center of Clinical Oncology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical University, Xuzhou, China.|Department of Pathology, Xuzhou Medical University, Xuzhou, China.
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Pei
mesh_terms: D017209:Apoptosis / Q000235:genetics; D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D063646:Carcinogenesis / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics*; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009361:Neoplasm Invasiveness / Q000235:genetics*; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: D051017:Apoptosis Regulatory Proteins; C541874:MIRN92 microRNA, human; D035683:MicroRNAs; C404190:TNFAIP8 protein, human
keywords: TNFAIP8; biomarker; gastric cancer; miR-9; proliferation