title: [Drug sensitivity research of mTOR inhibitor on breast cancer stem cells].
abstract: OBJECTIVE
  To test the antitumor effects of the mTOR inhibitor everolimus in breast cancer stem cells and total cells in vitro and in vivo.
  
  
  METHODS
  In vitro studies, we sorted ESA⁺ CD44⁺ CD24(-/low) cells as stem cells using flow cytometry from primary breast cancer cells. Apoptosis and the cell cycle distributions of stem cells were examined by flow cytometry. The tumorigenicity of stem cells after treatment was investigated by soft agar colony formation assays. BALB/c mice were injected with stem cells and the different treatments were administered. After necropsy, the expression of Ki67, CD31, AKT1, and phospho-AKT (Thr308) was analyzed by immunohistochemistry.
  
  
  RESULTS
  Treatment with everolimus resulted in growth inhibition of all stem cells in a dose-dependent manner. An increase in G0-G1 cell cycle arrest and an increased population of cells in early apoptosis were seen in everolimus treatment. In vivo, the volumes of the xenograft tumors significantly decreased in everolimus alone group compared to control group.
  
  
  CONCLUSIONS
  Everolimus could inhibit the growth of both total breast cancer cells and sorted stem cells in vitro and in vivo.
authors.affiliation: The 3rd Department of Breast Cancer, China Tianjin Breast Cancer Prevention, Treatment Research Center, Tianjin Medical University Cancer Institute and Hospital; Key Laboratory of Breast Cancer Prevention and Therapy of Ministry of Education; Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: The 3rd Department of Breast Cancer, China Tianjin Breast Cancer Prevention, Treatment Research Center, Tianjin Medical University Cancer Institute and Hospital; Key Laboratory of Breast Cancer Prevention and Therapy of Ministry of Education; Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, China.
authors.forename: Xiaobei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: The 3rd Department of Breast Cancer, China Tianjin Breast Cancer Prevention, Treatment Research Center, Tianjin Medical University Cancer Institute and Hospital; Key Laboratory of Breast Cancer Prevention and Therapy of Ministry of Education; Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: The 3rd Department of Breast Cancer, China Tianjin Breast Cancer Prevention, Treatment Research Center, Tianjin Medical University Cancer Institute and Hospital; Key Laboratory of Breast Cancer Prevention and Therapy of Ministry of Education; Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, China; Email: zhangjin@tjmuch.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis; D001943:Breast Neoplasms; D002453:Cell Cycle; D000068338:Everolimus; D005434:Flow Cytometry; D007150:Immunohistochemistry; D051379:Mice; D014411:Neoplastic Stem Cells; D047428:Protein Kinase Inhibitors; D058570:TOR Serine-Threonine Kinases
chemical_list: D047428:Protein Kinase Inhibitors; D000068338:Everolimus; D058570:TOR Serine-Threonine Kinases