title: Anti-tumor effects of pEgr-1-endostatin-TNF-α recombinant plasmid expression induced by ionizing radiation.
abstract: OBJECTIVE
  The aim of the present study was to investigate the anti-tumor effect of a pEgr-1-endostatin-TNF-α recombinant plasmid induced by ionizing radiation.
  
  
  METHODS
  Three hundred and twenty mice bearing Lewis lung carcinomas were divided into four experimental groups: blank control, irradiation treatment, plasmid treatment and plasmid combined irradiation treatment. Twenty-four hours after the recombinant plasmid was injected locally into the tumors of the mice, they were irradiated with 10 Gy γ -rays. The concentration of TNF-α and endostatin in the serum of mice was measured by ELISA and tumor growth in each group was compared. The tumor microvessel density was examined by H and E staining and immunohistochemistry analysis of CD31 positive cells.
  
  
  RESULTS
  Radiation could induce the expression of pEgr-1-endostatin-TNFα. The levels of endostatin and TNF-α could express steadily for about 4 weeks, with concentrations of 52.6 ± 4.19 and 12.0 ± 0.87 ng/ml respectively, in the second week in combined therapy group and maintained at relative higher level in the fourth week than other groups (F=29.7, P>0.05). Compared with the control group, the tumor micro vessel density was significantly depressed (P>0.05) and tumor growth was significantly inhibited (5907.2 ± 78.6 mm3 vs. 763.5 ± 12.3 mm3, P >0.05).
  
  
  CONCLUSIONS
  The expression of pEgr-1-endostatin-TNF-α could be induced in mice in vivo and exhibited more significant anti-tumor and anti-angiogenesis effects than irradiation alone.
authors.affiliation: Department of Oncology, Affiliated Hospital of Medical College, Qingdao University, Qingdao, China.
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wensheng
authors.initials: W
authors.lastname: Qiu
authors.forename: Jun
authors.initials: J
authors.lastname: Liang
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Yu
authors.forename: Lu
authors.initials: L
authors.lastname: Yue
mesh_terms: D000818:Animals; D018827:Carcinoma, Lewis Lung / Q000235:genetics / Q000532:radiotherapy / Q000628:therapy*; D049109:Cell Proliferation; D051766:Early Growth Response Protein 1 / Q000097:blood* / Q000235:genetics; D043169:Endostatins / Q000097:blood* / Q000235:genetics; D005720:Gamma Rays; D015316:Genetic Therapy / Q000379:methods*; D051379:Mice; D009389:Neovascularization, Pathologic; D010957:Plasmids; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood* / Q000235:genetics
chemical_list: D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D043169:Endostatins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D014409:Tumor Necrosis Factor-alpha