title: Inverse association between miR-194 expression and tumor invasion in gastric cancer.
abstract: BACKGROUND
  MiR-194 has been shown to be specifically expressed in the human gastrointestinal tract and may play an antimetastatic role in primary liver cancer cells. However, the role of miR-194 in gastric cancer is still unclear.
  
  
  METHODS
  Total RNA was extracted from tissues of 119 patients with gastric cancer and three gastric cancer cell lines (SGC-7901, MGC-803, and BGC-823). Expression levels of miR-194 were determined by real-time polymerase chain reaction (PCR). Moreover, a MTT proliferation assay and transwell cell invasion assay were performed to study the effect of miR-194 on SGC-7901 cell proliferation and invasion. Finally, we used real-time PCR and western blot to verify which gene was the target of miR-194 in gastric cancer.
  
  
  RESULTS
  Though there was no significant difference between cancerous and matching noncancerous tissues, we found patients with lower expression of miR-194 tended to have larger tumor size (P = 0.002) and more advanced pT stage (P = 0.028) in gastric cancer. Moreover, the expression of miR-194 was significantly lower in Borrmann IV type gastric cancer than in Borrmann I, II, and III types (P = 0.019). Furthermore, an in vitro invasion assay indicated that the penetrated cell intensity after miR-194 mimics transfection was significantly lower than the control. However, overexpression of miR-194 had little effect on the SGC-7901 cell cycle and proliferation. The results of real-time PCR and western blot highlighted that miR-194 interacted with N-cadherin and negatively regulated its expression at the translational level.
  
  
  CONCLUSIONS
  These findings imply that miR-194 might play an important role in gastric cancer invasion and progression.
authors.affiliation: Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, Shenyang, People's Republic of China.
authors.forename: Yongxi
authors.initials: Y
authors.lastname: Song
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.forename: Zhenning
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhuangkai
authors.initials: Z
authors.lastname: Liu
authors.forename: Yeunpo
authors.initials: Y
authors.lastname: Chiang
authors.forename: Yingying
authors.initials: Y
authors.lastname: Xu
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.forename: Huimian
authors.initials: H
authors.lastname: Xu
mesh_terms: D000368:Aged; D015820:Cadherins / Q000096:biosynthesis / Q000235:genetics*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D014176:Protein Biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D014162:Transfection; D047368:Tumor Burden
chemical_list: D015820:Cadherins; C554846:MIRN194 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger