title: Meta-analysis of estrogen response in MCF-7 distinguishes early target genes involved in signaling and cell proliferation from later target genes involved in cell cycle and DNA repair.
abstract: BACKGROUND
  Many studies have been published outlining the global effects of 17β-estradiol (E2) on gene expression in human epithelial breast cancer derived MCF-7 cells. These studies show large variation in results, reporting between ~100 and ~1500 genes regulated by E2, with poor overlap.
  
  
  RESULTS
  We performed a meta-analysis of these expression studies, using the Rank product method to obtain a more accurate and stable list of the differentially expressed genes, and of pathways regulated by E2. We analyzed 9 time-series data sets, concentrating on response at 3-4 hrs (early) and at 24 hrs (late). We found >1000 statistically significant probe sets after correction for multiple testing at 3-4 hrs, and >2000 significant probe sets at 24 hrs. Differentially expressed genes were examined by pathway analysis. This revealed 15 early response pathways, mostly related to cell signaling and proliferation, and 20 late response pathways, mostly related to breast cancer, cell division, DNA repair and recombination.
  
  
  CONCLUSIONS
  Our results confirm that meta-analysis identified more differentially expressed genes than the individual studies, and that these genes act together in networks. These results provide new insight into E2 regulated mechanisms, especially in the context of breast cancer.
authors: Department of Ecology and Evolution, University of Lausanne, Switzerland.
authors: Vidhya
authors: V
authors: Jagannathan
authors: Marc
authors: M
authors: Robinson-Rechavi
mesh_terms: D002453:Cell Cycle / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004260:DNA Repair / Q000235:genetics*; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000235:genetics; D053263:Gene Regulatory Networks / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D040081:Protein Array Analysis; D015398:Signal Transduction / Q000235:genetics*
chemical_list: D004958:Estradiol