title: Angiopoietin and vascular endothelial growth factor expression in colorectal disease models.
abstract: OBJECTIVE
  To investigate angiopoietin (Ang) and vascular endothelial growth factor (VEGF) expression in rats with ulcerative colitis (UC) and colorectal cancer (CRC).
  
  
  METHODS
  Dysplasia and cancer were investigated in rats that received three cycles of 3.5% dextran sulfate sodium (DSS) in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with 20 mg/kg 1,2-dimethylhydrazine (DMH) (CRC group). Colitis was investigated in rats that received three cycles of 3.5% DSS in drinking water for 7 d followed by distilled water for 14 d after intraperitoneal pretreatment with saline (UC group). Rats without DSS or DMH treatment served as controls. Expression of the tyrosine kinase with immunoglobulin-like and EGF-like domains (Tie)-2 and its ligands, Ang-1 and Ang-2, as well as VEGF were evaluated in the colorectum by Western blotting.
  
  
  RESULTS
  Compared with rats in the control group, rats in the CRC and UC groups developed the symptoms of acute colitis with diarrhea, rectal bleeding, wasting, and loss of body weight (P < 0.05). In addition, the mean length of colorectum of CRC and UC rats was significantly shorter than that of control rats (8.29 ± 0.21 and 8.31 ± 0.86, respectively, vs 12.34 ± 0.12 cm; P < 0.05). Furthermore, rats in the CRC group, but not in the UC or control groups, developed multiple tumors in the colorectal region. Western blot analysis revealed that rats in the CRC and UC groups had markedly increased protein levels of Ang-1, Ang-2, Tie-2, and VEGF in the colorectum compared to rats in the control group.
  
  
  CONCLUSIONS
  Increased expression of Ang-1, Ang-2, Tie-2, and VEGF in ulcerative colitis-derived colorectal cancer might lead to chronic colitis and pathologic angiogenesis in rats.
authors.affiliation: Wei-Xin Liu, Shen Zhang, Yi Ren, Li-Xuan Sang, Cong Dai, Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China.
authors.forename: Wei-Xin
authors.initials: WX
authors.lastname: Liu
authors.affiliation: Wei-Xin Liu, Shen Zhang, Yi Ren, Li-Xuan Sang, Cong Dai, Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China.
authors.forename: Shou-Zhi
authors.initials: SZ
authors.lastname: Gu
authors.affiliation: Wei-Xin Liu, Shen Zhang, Yi Ren, Li-Xuan Sang, Cong Dai, Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China.
authors.forename: Shen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Wei-Xin Liu, Shen Zhang, Yi Ren, Li-Xuan Sang, Cong Dai, Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Wei-Xin Liu, Shen Zhang, Yi Ren, Li-Xuan Sang, Cong Dai, Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China.
authors.forename: Li-Xuan
authors.initials: LX
authors.lastname: Sang
authors.affiliation: Wei-Xin Liu, Shen Zhang, Yi Ren, Li-Xuan Sang, Cong Dai, Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Dai
mesh_terms: D019813:1,2-Dimethylhydrazine; D042683:Angiopoietin-1 / Q000378:metabolism*; D042702:Angiopoietin-2 / Q000378:metabolism*; D000818:Animals; D003093:Colitis, Ulcerative / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D003106:Colon / Q000378:metabolism* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D016264:Dextran Sulfate; D004195:Disease Models, Animal; D008297:Male; D017208:Rats, Wistar; D042787:Receptor, TIE-2 / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D042683:Angiopoietin-1; D042702:Angiopoietin-2; C467629:Angpt1 protein, rat; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D016264:Dextran Sulfate; D042787:Receptor, TIE-2; D019813:1,2-Dimethylhydrazine
keywords: Angiopoietin-1; Angiopoietin-2; Colorectal cancer; Tie-2; Ulcerative colitis; Vascular endothelial growth factor