title: Relaxin promotes in vitro tumour growth, invasion and angiogenesis of human Saos-2 osteosarcoma cells by AKT/VEGF pathway.
abstract: OBJECTIVE
  In the present study, we determine the role of relaxin on cellular growth, invasion and angiogenesis of osteosarcoma Saos-2 cells in vitro, and discuss the molecular mechanisms of this action.
  
  
  METHODS
  Saos-2 cells were transfected with Akt1/2 siRNA or VEGF siRNA for 24 hours then treated with 10-100 ng/mL recombinant human relaxin-2 (rh-RLN) for 48 h. MTT, matrigel and bone marrow-derived endothelial cells (BMDECs) was used for cell proliferation, invasion and angiogenesis assay. Western blot was used for relaxin-2, pAKT and VEGF protein assay.
  
  
  RESULTS
  The results showed treatment with 10-100 ng/mL rh-RLN resulted in 18%, 48%, 107%, 212% increase in cell proliferation, respectively (vs control, *p < 0.05;**p < 0.01), the relative invasive cells was 1.4;1.9;2.6;4.8 (control was defined to 1) (vs control, #p < 0.01; ##p < 0.001) and the relative anglogenic branch points in Saos-2 cells was 1.04;1.36;1.69;2.10 (control was defined to 1.00) (vs control, *p < 0.05; **p < 0.01). Furthermore, treatment with rh-RLN exhibited a significant increase in the expression level of pAKT and VEGF proterin in dose-dependent manner. Saos-2 cells were transfected with AKT1/2 siRNA for 24 h. No significant increase of VEGF protein expression was shown after rh-RLN treatment.
  
  
  CONCLUSIONS
  These results suggested that rh-RLN could promoted proliferation, invasion and angiogenesis by upregulation pAKT-dependent VEGF expression.
authors.affiliation: Department of Spine, the Affiliated Hospital of Medical College, Qingdao University, China. Qyfymjf@126.com
authors.forename: J-F
authors.initials: JF
authors.lastname: Ma
authors.forename: M
authors.initials: M
authors.lastname: Von Kalle
authors.forename: Q
authors.initials: Q
authors.lastname: Plautz
authors.forename: F
authors.initials: F
authors.lastname: -M Xu
authors.forename: L
authors.initials: L
authors.lastname: Singh
authors.forename: L
authors.initials: L
authors.lastname: Wang
mesh_terms: D001859:Bone Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic / Q000209:etiology*; D012516:Osteosarcoma / Q000473:pathology*; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D012065:Relaxin / Q000494:pharmacology*; D015398:Signal Transduction / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*
chemical_list: D011994:Recombinant Proteins; D042461:Vascular Endothelial Growth Factor A; D012065:Relaxin; D051057:Proto-Oncogene Proteins c-akt