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Preparation Of Neovascular Tissues from Human Glioma Tissues for Quantitative Proteomics Analysis of Tumor Angiogenesis
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Antagonists of bombesin/gastrin-releasing peptide decrease the expression of angiogenic and anti-apoptotic factors in

Celia A Kanashiro1, Andrew V Schally, R-Z Cai

  • 1Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center and Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112-1262, USA.

Anti-Cancer Drugs
|January 19, 2005
PubMed

Insights

Bombesin/gastrin-releasing peptide (GRP) antagonists, RC-3940-II and RC-3940-Et, significantly inhibited human malignant glioma growth in mice. These GRP antagonists reduced tumor volume and promoted apoptosis, suggesting potential glioblastoma treatment applications.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • Bombesin/gastrin-releasing peptide (GRP) receptors are implicated in the growth of various cancers, including glioblastomas.
  • U-118MG human malignant glioma xenografts provide a model for investigating novel antitumor therapies.

Purpose of the Study:

  • To evaluate the antitumor efficacy of bombesin/GRP antagonists RC-3940-II and RC-3940-Et.
  • To elucidate the mechanism of action of these antagonists in human malignant glioma models.

Main Methods:

  • Treatment of U-118MG human malignant glioma xenografts in nude mice with RC-3940-II and RC-3940-Et.
  • Tumor volume measurement, Western blot analysis for VEGF, PKC-alpha, Bcl-2, and Bax expression, and radioreceptor assay.

Main Results:

  • Significant reduction in tumor volume (52.5% with RC-3940-II, 72.6% with RC-3940-Et) and prolonged tumor doubling time.
  • Decreased expression of vascular endothelial growth factor (VEGF) and protein kinase C (PKC)-alpha.
  • Reduced Bcl-2:Bax ratio, indicating increased apoptosis and treatment efficacy.

Conclusions:

  • Bombesin/GRP antagonists RC-3940-II and RC-3940-Et demonstrate significant antitumor activity against human malignant gliomas.
  • These antagonists represent a promising therapeutic strategy for glioblastoma treatment by targeting GRP signaling pathways.

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