title: Stable transfection of estrogen receptor-alpha suppresses expression of cyclooxygenase-2 and vascular endothelial growth factor-C in MDA-MB-231 breast cancer cells.
abstract: BACKGROUND
  Estrogen receptor (ER)-negative breast cancer cells are more aggressive than ER-positive cells. Elevated levels of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor-C (VEGF-C) expression have been detected in cultured human breast cancer cells and are associated with negative hormone receptor status. In this study, we created ERalpha stable transfectants in MDA-MB-231 cells to explore the effect of ERalpha on cell growth and COX-2 and VEGF-C expression.
  
  
  METHODS
  The green fluorescent protein (GFP)-ERalpha plasmids were stably transfected into ER-negative MDA-MB-231 cells. The proliferation and migration of untransfected MDA-MB-231 cells, ERalpha-transfected MDA-MB-231 cells and ER-positive MCF-7 cells were determined. The expression of COX-2, and the levels of VEGF-C mRNA and the VEGF-C secretion concentration were assayed in these cell lines.
  
  
  RESULTS
  The proliferation and migration capacities of ERalpha-tranfected MDA-MB-231 cells were significantly decreased (P < 0.05). The expression of COX-2 was significantly lower in ERalpha-tranfected MDA-MB-231 cells than in untranfected MDA-MB-231 cells. The mRNA and protein levels of VEGF-C were lower in ERalpha-tranfected MDA-MB-231 cells than in untransfected MDA-MB-231 cells (P < 0.05).
  
  
  CONCLUSIONS
  ERalpha stable transfection inhibits proliferation and migration capacities of MDA-MB-231 cells and decreases expression of COX-2 and VEGF-C. The decreases of proliferation and migration capacities may be related to suppression of COX-2 and VEGF-C expression.
authors.affiliation: Division of Breast Surgery, Department of Surgery, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Lin
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiao
authors.forename: San-ming
authors.initials: SM
authors.lastname: Wang
authors.forename: Xiang-xia
authors.initials: XX
authors.lastname: Liu
authors.forename: Shen-ming
authors.initials: SM
authors.lastname: Wang
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D049109:Cell Proliferation; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016133:Polymerase Chain Reaction; D014162:Transfection; D042582:Vascular Endothelial Growth Factor C / Q000235:genetics / Q000378:metabolism*
chemical_list: D047628:Estrogen Receptor alpha; D042582:Vascular Endothelial Growth Factor C; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human