title: Effect of different concentrations of medroxy-progesterone acetate combined with 17β-estradiol on endothelial progenitor cells.
abstract: OBJECTIVE
  Endothelial progenitor cells (EPCs) have the ability to differentiate into mature endothelial cells. Inhibition of EPC proliferation and migration may be a new method for anti-tumor therapy. Medroxyprogesterone acetate (MPA) may act on tumor angiogenesis by impacting biological functions of EPCs. The aim of this work was to study the effect of different concentrations of MPA combined with 17β-estradiol (17β-E2) on proliferation, migration, and apoptosis of EPCs in vitro.
  
  
  METHODS
  Proliferation tests (MTT analysis) and migration assay of EPCs, isolated from bone marrow of canine, were performed to detect their response to different concentrations of MPA combined with 17β-E2 (1 × 10(-8) mol/L). The growth curves were drawn every 24 h for 7 consecutive days. The cell cycle and apoptosis of EPCs were analyzed by flow cytometry.
  
  
  RESULTS
  17β-E2 (1 × 10(-8) mol/L) increased EPC proliferation, while lower concentration of MPA (≤ 10(-5) mol/L) partially inhibited it. The higher concentration of MPA (≥ 10(-4) mol/L) combined with 17β-E2 had a significant inhibitory effect on EPC growth, arresting it in the S phase. It also increased the apoptosis rate and damaged the migration ability of EPCs.
  
  
  CONCLUSIONS
  Low concentration of MPA partially inhibited the function of 17β-E2 that promotes the proliferation of EPCs. However, high concentration of MPA combined with 17β-E2 inhibited a variety of biological functions of EPCs. So, the MPA has a bidirectional effect combined with 17β-E2 on the cell biology of EPCs.
authors.affiliation: Cardiac Development and Early Intervention Research Unit, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China. zhangyi125@gmail.com.
authors.forename: L-H
authors.initials: LH
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Lai
authors.forename: L-J
authors.initials: LJ
authors.lastname: Linghu
authors.forename: Y-F
authors.initials: YF
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D004285:Dogs; D004347:Drug Interactions / Q000502:physiology; D066026:Endothelial Progenitor Cells / Q000187:drug effects* / Q000378:metabolism*; D004958:Estradiol / Q000008:administration & dosage* / Q000378:metabolism*; D005260:Female; D006801:Humans; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage* / Q000378:metabolism*
chemical_list: D004958:Estradiol; D017258:Medroxyprogesterone Acetate