title: Estrogen increases secretion of stromal cell derived factor-1 in human breast cancer cells.
abstract: OBJECTIVE
  Stromal cell derived factor-1 (SDF-1) is closely related to the biological characteristics of breast cancer. The aim of this article is to investigate if estrogen affects the biological characteristics of breast cancer via affecting secretion of SDF-1.
  
  
  METHODS
  The breast cancer cell lines MCF-7 and MDA-MB-231 used in this study were divided into control group, estrogen group and estrogen plus estrogen receptor (ER) antagonist group. These groups were treated with different concentrations of 17-β estradiol or the same concentration of 17-β estradiol for different times, respectively. Enzyme-linked immunosorbent assay and semi-quantitative reverse transcriptase polymerase chain reaction were performed.
  
  
  RESULTS
  Secretion of SDF-1 was detected in the cell basal medium of MCF-7. When adding a high physiological concentrations of 17-β estradiol (10(-7) mol/L), the levels of SDF-1 secretion achieved a peak at 2 h and it was 6 times of control group (1823.16 ± 325.18 pg/ml comparing to 308.23 ± 9.23 pg/ml, P < 0.01). However, this effect could be eliminated by the pure estrogen antagonist ICI182 or ICI780. The SDF-1 mRNA levels were consistent with the determined SDF-1 protein levels. At the time point of 2 h, for the 10(-7) mol/L group, the SDF-1 mRNA expression levels were higher than the antagonist group, with statistically significant differences (P < 0.05).
  
  
  CONCLUSIONS
  It was found that secretion of SDF-1 can be increased by the physiological concentrations of estrogen mainly through regulation of estrogen receptor.
authors: Department of General Surgery, Capital Medical University School of Rehabilitation, Beijing Charity Hospital, China Rehabilitation Research Center Beijing 100068, P. R. China.
authors: Fengliang
authors: F
authors: Zhang
authors: Department of General Surgery, Xuanwu Hospital, Capital Medical University Beijing 100068, P. R. China.
authors: Hua
authors: H
authors: Kang
authors: Department of General Surgery, Capital Medical University School of Rehabilitation, Beijing Charity Hospital, China Rehabilitation Research Center Beijing 100068, P. R. China.
authors: Qing
authors: Q
authors: Xu
keywords: 17-βestradiol; Breast cancer; MCF-7; MDA-MB-231; SDF-1