title: [Effects of sodium selenite on the expressions of beta-catenin and its target cyclin D1 in colorectal cancer cells HCT 116 and SW480].
abstract: OBJECTIVE
  To explore the effects of sodium selenite on the expressions of beta-catenin and cyclin D1 in colorectal cancer cells HCT 116 and SW480.
  
  
  METHODS
  HCT 116 and SW480 cells were treated by 10 micromol/L sodium selenite at different time points. The expressions and transcription of beta-catenin and cyclin D1 were detected by Western blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR), respectively. Meanwhile, the impact of MG132 (a proteasome inhibitor) pretreatment on the expressions of beta-catenin and cyclin D1 was observed through Western blot analysis. The interaction between beta-catenin and T cell factor 4 (TCF4) after selenite treatment was evaluated using co-immunoprecipitation assay.
  
  
  RESULTS
  Sodium selenite inhibited the expression of beta-catenin and transcription of its target such as cyclin D1. MG132 pretreatment prevented the inhibition of beta-catenin signaling triggered by selenite in HCT 116 and SW480 cells. Furthermore, selenite treatment disrupted the interaction between beta-catenin and TCF4 in HCT 116 and SW480 cells.
  
  
  CONCLUSIONS
  Sodium selenite can lower the expression levels of beta-catenin and its target cyclin D1, during which the proteasome-mediated degradative pathway may be involved. The decreased interaction between beta-catenin and TCF4 due to sodium selenite may be also involved in the regulation of beta-catenin signaling.
authors.affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Luo
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Cai-Min
authors.initials: CM
authors.lastname: Xu
mesh_terms: D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000378:metabolism*; D019938:Cyclin D1 / Q000378:metabolism*; D045325:HCT116 Cells; D006801:Humans; D018038:Sodium Selenite / Q000494:pharmacology*; D051176:beta Catenin / Q000378:metabolism*
chemical_list: C530104:CCND1 protein, human; C495270:CTNNB1 protein, human; D051176:beta Catenin; D019938:Cyclin D1; D018038:Sodium Selenite