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Downregulation of tumstatin expression by overexpression of ornithine decarboxylase

Wei Wang1, Chun-Xiao Xu, Guo-Sheng Hou

  • 1Institute of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China.

Oncology Reports
|September 5, 2013
PubMed

Insights

Ornithine decarboxylase (ODC) overexpression suppresses tumstatin, an angiogenesis inhibitor. This finding offers evidence for combining anti-angiogenesis therapy with conventional cancer treatments.

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • Tumor angiogenesis is crucial for cancer growth and metastasis.
  • Anti-angiogenesis therapy is a promising cancer treatment strategy.
  • Tumstatin is an endogenous inhibitor of angiogenesis, while Ornithine Decarboxylase (ODC) is overexpressed in many cancers and linked to tumor progression.

Purpose of the Study:

  • To investigate the relationship between Ornithine Decarboxylase (ODC) overexpression and tumstatin expression.
  • To test the hypothesis that ODC overexpression downregulates tumstatin expression.

Main Methods:

  • Generation of HEK293 cells overexpressing ODC.
  • Analysis of tumstatin expression using reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot.
  • Assessment of tumstatin gene promoter activity via dual luciferase reporter assay.

Main Results:

  • ODC-overexpressing cells and putrescine-treated cells exhibited suppressed tumstatin mRNA and protein levels.
  • Tumor angiogenesis inhibitor tumstatin gene promoter activity was decreased in ODC-overexpressing cells.
  • ODC overexpression was found to downregulate tumstatin expression.

Conclusions:

  • ODC overexpression suppresses tumstatin expression.
  • This provides fundamental evidence supporting the combination of anti-angiogenic therapy with conventional cancer treatments.

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