title: [Effects of tamoxifen on apoptosis and matrix metalloproteinase-7 expression in estrogen receptor beta-positive colonic cancer cell line HT-29].
abstract: OBJECTIVE
  Studies have shown that estrogen receptor beta (ERbeta), which is highly expressed in colorectal cancer, is related to tumor metastasis. Matrix metalloproteinase (MMP)-7 is overexpressed in colorectal cancer, and plays an important role in tumor invasion and metastasis. This study was to explore the effect of tamoxifen (TAM) on apoptosis and MMP-7 expression in ERbeta-positive human colorectal cancer cell line HT-29.
  
  
  METHODS
  After exposure to TAM, the proliferation of HT-29 cells was detected by MTT assay; cell apoptosis was evaluated using flow cytometry; expressions of ERbeta and MMP-7 were measured by Western blot.
  
  
  RESULTS
  TAM significantly inhibited cell growth of HT-29 in a time (24 h, 48 h, 72 h )-and dose (0, 10(-7), 10(-6), 10(-5),0 10(-4) mol/L )-dependent manner. TAM exposure caused significant cell apoptosis of HT-29 cells at the concentration of 10(-4) mol/L [(69.9+/-4.2)%]. Moreover, TAM could bind to ERbeta to down-regulate MMP-7 protein expression in HT-29 cells.
  
  
  CONCLUSIONS
  High concentration of TAM can inhibit the proliferation of ERbeta-positive HT-29 cells, and effectively bind with ERbeta to down-regulate MMP-7 expression.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, China.
authors.forename: Yu-Jing
authors.initials: YJ
authors.lastname: Fang
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Wang
authors.forename: Zhen-Hai
authors.initials: ZH
authors.lastname: Lu
authors.forename: Li-Yi
authors.initials: LY
authors.lastname: Zhang
authors.forename: Zhi-Zhong
authors.initials: ZZ
authors.lastname: Pan
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Zhou
authors.forename: De-Sen
authors.initials: DS
authors.lastname: Wan
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation; D047629:Estrogen Receptor beta / Q000378:metabolism*; D019073:HT29 Cells; D006801:Humans; D020783:Matrix Metalloproteinase 7 / Q000378:metabolism*; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047629:Estrogen Receptor beta; D013629:Tamoxifen; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7