[Expressions and activities of Rho GTPases in hypoxia and its relationship with tumor angiogenesis]

Zhonghua Zhong Liu Za Zhi. 2004 Sep;26(9):517-20.
[Article in Chinese]

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.

Conclusion: These results indicate that hypoxia enhances Rac1 expression which might be involved in tumor angiogenesis by reacting with hypoxia-responsive genes.

Publication types

  • English Abstract
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Hypoxia
  • Cell Line, Tumor
  • Hepatoblastoma / blood supply
  • Hepatoblastoma / metabolism*
  • Hepatoblastoma / pathology
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / biosynthesis
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Liver Neoplasms / blood supply
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / pathology
  • Neovascularization, Pathologic*
  • PTEN Phosphohydrolase / biosynthesis
  • PTEN Phosphohydrolase / genetics
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Stomach Neoplasms / blood supply
  • Stomach Neoplasms / metabolism*
  • Stomach Neoplasms / pathology
  • Tumor Suppressor Protein p53 / biosynthesis
  • Tumor Suppressor Protein p53 / genetics
  • Vascular Endothelial Growth Factor A / biosynthesis
  • Vascular Endothelial Growth Factor A / genetics
  • rac1 GTP-Binding Protein / biosynthesis*
  • rac1 GTP-Binding Protein / genetics
  • rho GTP-Binding Proteins / biosynthesis*
  • rho GTP-Binding Proteins / genetics

Substances

  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • RNA, Messenger
  • Tumor Suppressor Protein p53
  • Vascular Endothelial Growth Factor A
  • PTEN Phosphohydrolase
  • rac1 GTP-Binding Protein
  • rho GTP-Binding Proteins