title: [Expressions and activities of Rho GTPases in hypoxia and its relationship with tumor angiogenesis].
abstract: OBJECTIVE
  To study the expressions and activities of Rho GTPases in hypoxia and its relationship with tumor angiogenesis.
  
  
  METHODS
  Three tumor cell lines were used in this study: gastric cancer cell lines AGS, SGC7901 and hepatocellular carcinoma cell line HepG2. Expression level of Rac1 mRNA was detected by semi-quantitative RT-PCR. Activity of Rac1 was determined by pull-down assay and expression of HIF-1alpha, VEGF, p53 and PTEN protein was detected by Westernblot.
  
  
  RESULTS
  The expression level of Rac1 mRNA was significantly increased in hypoxia compared to normoxia. Pull-down assay showed that hypoxia-induced activity of Rac1 was elevated in a time-dependent manner and climaxed at 3 hours. The expressions of HIF-1alpha and VEGF protein were up-regulated, while those of PTEN and p53 protein were down-regulated.
  
  
  CONCLUSIONS
  These results indicate that hypoxia enhances Rac1 expression which might be involved in tumor angiogenesis by reacting with hypoxia-responsive genes.
authors.affiliation: Insitute of Digestive Diseases, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xue
authors.forename: Feng
authors.initials: F
authors.lastname: Bi
authors.forename: Wen-chao
authors.initials: WC
authors.lastname: Liu
authors.forename: Yang-lin
authors.initials: YL
authors.lastname: Pan
authors.forename: Zhe-yi
authors.initials: ZY
authors.lastname: Han
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.forename: Chang-jiang
authors.initials: CJ
authors.lastname: Liu
authors.forename: Hui-qin
authors.initials: HQ
authors.lastname: Shen
authors.forename: Xue-yong
authors.initials: XY
authors.lastname: Zhang
mesh_terms: D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D018197:Hepatoblastoma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis / Q000235:genetics; D008113:Liver Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D009389:Neovascularization, Pathologic; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D013274:Stomach Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000235:genetics; D020830:rac1 GTP-Binding Protein / Q000096:biosynthesis* / Q000235:genetics; D020741:rho GTP-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D042461:Vascular Endothelial Growth Factor A; D051059:PTEN Phosphohydrolase; D020830:rac1 GTP-Binding Protein; D020741:rho GTP-Binding Proteins