Cisplatin and doxorubicin repress Vascular Endothelial Growth Factor expression and differentially down-regulate Hypoxia-inducible Factor I activity in human ovarian cancer cells

Biochem Pharmacol. 2007 Jul 15;74(2):191-201. doi: 10.1016/j.bcp.2007.04.003. Epub 2007 Apr 6.

Abstract

Vascular Endothelial Growth Factor (VEGF) and its transcriptional regulator Hypoxia-inducible Factor 1 (HIF-1) play an important role in the process of angiogenesis in many types of cancer, including ovarian cancer. We have examined whether the DNA-damaging drugs cisplatin and doxorubicin and the microtubule inhibitors docetaxel and paclitaxel can affect VEGF expression and HIF-1 activity in three human ovarian cancer cell lines. We demonstrate that cisplatin and doxorubicin abolish hypoxia-induced VEGF mRNA expression in all cell lines, while basal VEGF mRNA expression was also downregulated. Transient transfection with a HIF-1-responsive luciferase construct indicated that cisplatin and doxorubicin inhibited hypoxic activation of HIF-1. Cisplatin repressed HIF-1alpha protein expression in all cell lines. Stimulation of HIF-1alpha protein degradation by cisplatin was observed in the only cell line expressing wild-type p53. Cisplatin also inhibited the synthesis of HIF-1alpha protein for which p53 was dispensable. Interestingly, cisplatin strongly reduced the protein levels of the HIF-1 coactivators p300 and CREB-binding protein (CBP) under hypoxia in all cell lines. Although doxorubicin inhibited hypoxic activation of HIF-1, this drug had no significant effect on the expression levels of HIF-1alpha and hypoxic expression of p300 and CBP was only weakly reduced. Docetaxel and paclitaxel did neither influence VEGF expression nor hypoxia-induced HIF-1 activity. In total, our findings indicate that cisplatin and doxorubicin can repress hypoxic induction of VEGF expression by inhibiting HIF-1 through different mechanisms. This knowledge may be useful for future treatment schedules including agents that target the HIF-1 signalling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / genetics
  • Antineoplastic Agents / pharmacology*
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases / genetics
  • Carrier Proteins / genetics
  • Cell Line, Tumor
  • Cisplatin / pharmacology*
  • Corticosterone
  • Down-Regulation
  • Doxorubicin / pharmacology*
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects*
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics*
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / pathology
  • Vascular Endothelial Growth Factor A / genetics*
  • p300-CBP Transcription Factors / genetics

Substances

  • Antigens, Neoplasm
  • Antineoplastic Agents
  • Carrier Proteins
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Vascular Endothelial Growth Factor A
  • Doxorubicin
  • p300-CBP Transcription Factors
  • CA9 protein, human
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases
  • Cisplatin
  • Corticosterone