title: [Roles of Y box-binding protein 1 in SK-BR-3 breast cancer proliferation].
abstract: OBJECTIVE
  To explore the roles of Y box-binding protein 1 (YB-1) in breast cancer cell proliferation.
  
  
  METHODS
  Twenty cases of surgical removal of breast cancer tissue (diagnosed with invasive ductal carcinoma, stage II, by postoperative paraffin pathology) and normal breast tissues adjacent to carcinoma were collected during June 2013 to August 2013.Quantitative real-time PCR (qRT-PCR) was performed to detect the YB1 mRNA levels. Cultured mammary epithelial cells (HBL-100) and breast cancer cells (MCF7, MDA-MB-231 & SK-BR-3 cells) were harvested and qRT-PCR was performed to detect the YB1 mRNA levels.SK-BR-3 cells were stimulated with various concentrations of PDGF-BB and YB1 expression levels were detected by qRT-PCR. Down-regulation or over-expression of YB1 by si-YB1 or Ad-GFP-YB1 was detected in SK-BR-3 cells. And MTS cell proliferation assay kit was used to detect cell proliferation.
  
  
  RESULTS
  YB1 mRNA levels were significantly higher in breast cancer tissues and MDA-MB-231 and SK-BR-3 breast cancer cell lines than that in adjacent normal breast tissues and HBL-100 mammary epithelial cells respectively (P < 0.05).YB1 expression levels increased in PDGF-BB stimulated SK-BR-3 cells in a dose-dependent manner.
  
  
  CONCLUSIONS
  A down-regulation of endogenous YB1 decreases and an over-expression of exogenous YB1 promotes the proliferation activity in SK-BR-3 cells.
authors.affiliation: Central Laboratory, Affiliated Hospital of Hebei University, Baoding 071000, China.
authors.forename: Jianhong
authors.initials: J
authors.lastname: Shi
authors.forename: Xinrui
authors.initials: X
authors.lastname: Lü
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Daudan
authors.forename: Wang
authors.initials: W
authors.lastname: Yanan
authors.forename: Bu
authors.initials: B
authors.lastname: Yuhui
authors.forename: Ma
authors.initials: M
authors.lastname: Zhenfeng
mesh_terms: D000077214:Becaplermin; D001943:Breast Neoplasms; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D006801:Humans; D020574:Proto-Oncogene Proteins c-sis; D051840:Y-Box-Binding Protein 1
chemical_list: D020574:Proto-Oncogene Proteins c-sis; D051840:Y-Box-Binding Protein 1; D000077214:Becaplermin