title: Effects and mechanism of miR-214 on hepatocellular carcinoma.
abstract: OBJECTIVE
  To explore the role of miR-214 in the progression of hepatocellular carcinoma (HCC) and its inhibitory mechanisms in depressing the signaling pathway of β-catenin, this study was conducted.
  
  
  METHODS
  We ectopically expressed miR-214 in HepG2 cells to obtain cell lines Lv-miR-214-HepG2 and their control Lv-control-HepG2. Differences between the two cell lines were compared in cell growth, proliferation, colony forming ability and cell cycles. RT-PCR method was applied for the quantification of β-catenin mRNA expression. Western-blot method was applied for the determination of the protein level of β-catenin and their downstream targets (ie. Cyclin D1, c-Myc and TCF-1). The effect of miR-214 on cells was further explored through RNA interference and restoring miR-214 expression.
  
  
  RESULTS
  In comparison with negative (Lv-control-HepG2) and blank (HepG2) control, a significant inhibition of cell growth and proliferation caused by miR-214 was observed after 48∼72h of cell culture experiments (P<0.05). The miR-214 treatment resulted in a colony forming efficiency of (23.28±3.26)%, which was significantly lower than that of negative control [(51.31±3.97)%] (P<0.05). According to FCM results, the experimental group, compared with control, showed a higher proportion of cells in G0/G1 phase [(70.32±3.12)%] but a lower proportion in S phase [(18.42±2.90)%] (P<0.05). The MTT assay demonstrated a significant inhibition of the proliferation and β-catenin expression of HCC cells compared with control (P<0.05), while no significant difference was observed after HCC cells being transfected with β-catenin overexpression plasmid (P>0.05). By comparing to the RT-PCR and Western-blot results of control, the miR-214 treatment led to a slightly decrease in the β-catenin mRNA expression (P>0.05), but an extremely inhibition in the protein level of β-catenin and its downstream targets Cyclin D1, c-Myc, and TCF-1 (P<0.05).
  
  
  CONCLUSIONS
  miR-214 functions as a suppressor during the progression of HCC, and its inhibitory role was achieved by down-regulating β-catenin signaling pathway.
authors.affiliation: Department of Gastroenterology, Qiqihaer Medical College Affiliated training hospital Daqing Oil Field General Hospital, Daqing City, Heilongjiang Province, China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, Qiqihaer Medical College Affiliated training hospital Daqing Oil Field General Hospital, Daqing City, Heilongjiang Province, China.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Guo
authors.affiliation: Department of Gastroenterology, Qiqihaer Medical College Affiliated training hospital Daqing Oil Field General Hospital, Daqing City, Heilongjiang Province, China.
authors.forename: Chun-Na
authors.initials: CN
authors.lastname: Zhao
authors.affiliation: Department of Gastroenterology, Qiqihaer Medical College Affiliated training hospital Daqing Oil Field General Hospital, Daqing City, Heilongjiang Province, China. Electronic address: zhanglili020@126.com.
authors.forename: Jian-Yun
authors.initials: JY
authors.lastname: Gao
keywords: Hepatocellular carcinoma; miR-214; β-catenin pathway