title: SDF-1/CXCR7 axis regulates the proliferation, invasion, adhesion, and angiogenesis of gastric cancer cells.
abstract: BACKGROUND
  More recent studies have revealed that chemokine receptor CXCR7 plays an important role in cancer development. However, little is known about the effect of CXCR7 on the process of gastric cancer cell invasion and angiogenesis. The aim of this study is to investigate the expression of CXCR7 in gastric cancer cell lines and to evaluate the role of CXCR7 in the proliferation, invasion, adhesion, and angiogenesis of gastric cancer cells.
  
  
  METHODS
  Real-time PCR and Western blotting were used to examine the mRNA and protein levels of CXCR4 and CXCR7 in five gastric cancer cell lines (HGC-27, MGC-803, BGC-823, SGC-7901, and MKN-28). CXCR7-expressing shRNA was constructed and subsequently stably transfected into the human gastric cancer cells. In addition, the effect of CXCR7 inhibition on cell proliferation, invasion, adhesion, VEGF secretion, and tube formation was evaluated.
  
  
  RESULTS
  The mRNA and protein of CXCR7 were expressed in all five gastric cancer cell lines; in particular, the expression of CXCR7 was the highest in SGC-7901 cells. Stromal cell-derived factor-1 (SDF-1) was found to induce proliferation, invasion, adhesion, and tube formation. Moreover, the VEGF secretion in SGC-7901 cells was also enhanced by SDF-1 stimulation. These biological effects were inhibited by the silencing of CXCR7 in SGC-7901 cells.
  
  
  CONCLUSIONS
  Increased CXCR7 expression was found in gastric cancer cells. Knockdown of CXCR7 expression by transfection with CXCR7shRNA significantly inhibits SGC-7901 cells' proliferation, invasion, adhesion, and angiogenesis. This study provides new insights into the significance of CXCR7 in the invasion and angiogenesis of gastric cancer.
authors.affiliation: Department of Hepatobiliary and Vascular Surgery, People's Hospital of Dezhou, Dezhou, Shandong Province, 253014, People's Republic of China.
authors.forename: De-Min
authors.initials: DM
authors.lastname: Ma
authors.affiliation: Department of Gastrointestinal Surgery, People's Hospital of Dezhou, 1751 Xin Hu Road, Dezhou, Shandong Province, 253014, People's Republic of China.
authors.forename: Dian-Xi
authors.initials: DX
authors.lastname: Luo
authors.affiliation: Department of Gastrointestinal Surgery, People's Hospital of Dezhou, 1751 Xin Hu Road, Dezhou, Shandong Province, 253014, People's Republic of China. dzzxy2066@163.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D054377:Chemokine CXCL12 / Q000235:genetics / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D047468:Immunoprecipitation; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D054387:Receptors, CXCR / Q000235:genetics / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured
chemical_list: C501896:ACKR3 protein, human; C515255:CXCL12 protein, human; C527276:CXCR4 protein, human; D054377:Chemokine CXCL12; D012333:RNA, Messenger; D054387:Receptors, CXCR; D019718:Receptors, CXCR4
keywords: CXC chemokine receptor-7; Chemokines; Gastric cancer; Metastasis; Stromal cell-derived factor-1