title: [Inhibition of K562 cell growth and tumor angiogenesis in nude mice by transfection of anti-VEGF hairpin ribozyme gene into the cells].
abstract: OBJECTIVE
  To explore the effect of anti-VEGF hairpin ribozyme gene on the tumor cell growth and tumor angiogenesis in nude mice.
  
  
  METHODS
  The recombinant eukaryotic expression plasmid pcDNA-RZ containing anti-VEGF hairpin ribozyme gene and the empty vector plasmid pcDNA were introduced separately into K562 cells by lipofectamine mediation and positive clones were screened by G418. Ribozyme gene in K562 cells was confirmed by PCR. Fluorescent real time RT-PCR and Western blot were used to detect the expression of VEGF mRNA and protein in the leukemia cells. The tumorigenicity of transfected K562 cells were transplanted in nude mice and tumor microvascular density (MVD) were observed by morphology and vWF immunohistochemistry stain.
  
  
  RESULTS
  Stable expression of the ribozyme gene in K562 cells was confirmed by PCR. The level of VEGF mRNA and protein decreased dramatically in K562/RZ cells when compared with K562 or K562/PC (K562 cells transfected with empty vector) cells. The tumor volumes were (4.43 +/- 0.87), (3.96 +/- 0.94), (2.24 +/- 0.56) cm3; tumor weight was (4.43 +/- 0.87), (3.96 +/- 0.94), (2.24 +/- 0.56)g; and tumor microvascular density was 4.70 +/- 1.25, 4.67 +/- 1.31, 1.80 +/- 1.55 in K562, K562/PC and K562/RZ cell groups, respectively.
  
  
  CONCLUSIONS
  Transfection with anti-VEGF ribozyme gene can inhibit tumor growth and vessel formation by down-regulating the VEGF gene expression in K562 cells.
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang 212002, China.
authors.forename: Wen-Lin
authors.initials: WL
authors.lastname: Xu
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Shen
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
authors.forename: Fa-Chun
authors.initials: FC
authors.lastname: Wang
authors.forename: Yun-Wei
authors.initials: YW
authors.lastname: Jiang
mesh_terms: D000818:Animals; D006801:Humans; D020014:K562 Cells; D051379:Mice; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000517:prevention & control*; D016337:RNA, Catalytic / Q000235:genetics*; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D016337:RNA, Catalytic; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C418481:hairpin ribozyme