title: Gene silencing of β-catenin by RNAi inhibits proliferation of human esophageal cancer cells by inducing G0/G1 cell cycle arrest.
abstract: OBJECTIVE
  The aim of the present study was to explore mechanisms underlying the effects of down-regulating β-catenin expression on esophageal carcinoma (EC) cells.
  
  
  METHODS
  Cell cycle distribution and apoptosis were determined using flow cytometry and annexin V apoptosis assay, respectively. Transmission electron microscopy (TEM) was used to examine changes in ultrastructure, while expression of cyclin D1 protein and mRNA was detected by western blot and real-time PCR. Proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated kinase (ERK) 1/2 were evaluated by Western blot analysis. PCNA labeling index (LI) was determined by immunocytochemistry.
  
  
  RESULTS
  Compared with pGen-3-con transfected and Eca-109 cells, the percentage of G0/G1-phase pGen-3-CTNNB1 transfected cells was obviously increased (P<0.05), with no significant difference among the three groups with regard to apoptosis (P>0.05). pGen-3-CTNNB1 transfected cells exhibited obvious decrease in cyclin D1 mRNA and protein expression (P<0.05) and the ultrastructure of Eca-109 cells underwent a significant change after being transfected with pGen-3-CTNNB1, suggesting that down-regulating β-catenin expression can promote the differentiation and maturation. The expression of PCNA and the ERKI/2 phosphorylation state were also down-regulated in pGen-3-CTNNB1 transfected cells (P<0.05). At the same time, the PCNA labeling index was decreased accordingly (P<0.05).
  
  
  CONCLUSIONS
  Inhibition of EC Eca-109 cellproliferation by down-regulating β-catenin expression could improve cell ultrastructure by mediating blockade in G0/G1 through inhibiting cyclin D1, PCNA and the MAPK pathway (p-ERK1/2).
authors.affiliation: Central Laboratory, Peace Hospital Affiliated to Changzhi Medical University, Changzhi, China.
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Wang
authors.forename: Ai-Fang
authors.initials: AF
authors.lastname: Ji
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Wan
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Lu
authors.forename: Jian-Zhou
authors.initials: JZ
authors.lastname: Yang
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Ma
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Wang
authors.forename: Wu
authors.initials: W
authors.lastname: Wei
mesh_terms: D017209:Apoptosis; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000096:biosynthesis; D015536:Down-Regulation; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis / Q000235:genetics; D059585:G1 Phase Cell Cycle Checkpoints; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020935:MAP Kinase Signaling System / Q000235:genetics; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
chemical_list: C495270:CTNNB1 protein, human; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051176:beta Catenin; D019938:Cyclin D1; D048049:Extracellular Signal-Regulated MAP Kinases