title: Dopamine inhibits proliferation, induces differentiation and apoptosis of K562 leukaemia cells.
abstract: BACKGROUND
  Dopamine exerts its effects mainly in nervous system through D1, D2 or D3 receptors. There are few reports dealing with the effects of dopamine on leukaemia cells. However, some dopamine agonists or antagonists do show biological effects on some types of leukaemia cells. Here, we report the effects of dopamine on the proliferation, differentiation and apoptosis of K562 leukaemia cells.
  
  
  METHODS
  Proliferation was determined by MTT assay and cell counting both in liquid and semisolid cultures. Differentiation was verified by morphology, benzidine staining and flow cytometry. Apoptosis was checked by Hoechst 33258 staining and flow cytometry. The two groups were untreated group and treated group (dopamine 10(-9) mol/L - 10(-4) mol/L).
  
  
  RESULTS
  In liquid culture, MTT assay and colony assay, dopamine inhibited proliferation of K562 cells. Inhibition rate was 29.28% at 10(-6) mol/L and 36.10% at 10(-5) mol/L after culture for 5 days in MTT assay. In benzidine staining and CD71 expression, dopamine induced K562 cells toward erythroid differentiation by increased 155% at 10(-6) mol/L and by 171% at 10(-5) mol/L after culture for 5 days in benzidine staining. In Hoechst 33258 staining and flow cytometry, dopamine induced K562 cells toward apoptosis. The sub G1 peak stained by PI was 14.23% at 10(-4) mol/L dopamine after culture for 3 days compared with the control (0.81%) in flow cytometry.
  
  
  CONCLUSIONS
  Dopamine inhibites proliferation and induces both differentiation and apoptosis of K562 leukaemia cells.
authors.affiliation: Research Laboratory of Blood Physiology, Department of Physiology, Xiangya School of Medicine, Central South University, Changsha 410078, China. hequn888@yahoo.com
authors.forename: Qun
authors.initials: Q
authors.lastname: He
authors.forename: Lin-bo
authors.initials: LB
authors.lastname: Yuan
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D004298:Dopamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D020014:K562 Cells / Q000166:cytology / Q000187:drug effects*
chemical_list: D004298:Dopamine