title: miR-429 modulates the expression of c-myc in human gastric carcinoma cells.
abstract: OBJECTIVE
  MicroRNAs (miRNAs) are a recently discovered class of small non-coding RNAs that regulate gene expression and may contribute to the development and progression of many cancers. In this study, our goal was to investigate the regulation of miR-429 in gastric cancer and explored the mechanism/s by which it influenced pathogenesis of gastric cancer.
  
  
  METHODS
  We used real-time reverse transcriptase-polymerase chain reaction to quantify the expression level of miR-429 in 52 gastric cancer tissues and their paracancerous tissues. Bioinformatics was used to predict downstream target genes of miR-429. SGC-7901 gastric cancer cells were transfected with miR-429 mimics and endogenous c-myc expression was detected by western blots. We performed functional assays using the 3'UTR of the c-myc gene as a miR-429 target in a luciferase reporter assay system.
  
  
  RESULTS
  We showed that miR-429 was downregulated in human gastric carcinoma tissue and in SGC-7901 cells. Cell viability, proliferation and attachment were inhibited in miR-429-transfected cells. miR-429 significantly downregulated endogenous c-myc expression in SGC-7901 cells. Action of miR/429 on c-myc 3'UTR was confirmed. The levels of miR-429 in tumour tissue of patients with lymph node metastasis were significantly lower than in those without lymph node metastasis.
  
  
  CONCLUSIONS
  Our results suggested that miR-429 played a role in the pathogenesis of gastric carcinoma and may function as a recessive cancer gene. c-myc is an important miR-429 target gene.
authors.affiliation: Department of General Surgery, Second Affiliated Hospital of Harbin Medical University, Hei LongJiang, Harbin, China.
authors.forename: Tiewei
authors.initials: T
authors.lastname: Sun
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Xing
authors.forename: Dequan
authors.initials: D
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D015153:Blotting, Western; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc / Q000235:genetics*; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C116115:MYCBP protein, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; D014157:Transcription Factors