Abstract
Purpose: Vinblastine and rapamycin displayed synergistic inhibition of human neuroblastoma-related angiogenesis. Here, we studied the antitumor activity of vinblastine and rapamycin against human neuroblastoma.
Experimental Design: Cell proliferation, cell cycle progression, and apoptosis were evaluated by measuring 3H-thymidine incorporation, bromodeoxyuridine uptake, and phosphatidylserine exposure, respectively. The in vivo sensitivity of neuroblastoma cells to vinblastine and rapamycin was determined in orthotopic neuroblastoma-engrafted mice. Angiogenesis was assessed by the chick embryo chorioallantoic membrane assay.
Results: Each compound alone was able to induce a dose-dependent significant inhibition of cell proliferation, with a dramatically enhanced antiproliferative effect for the drugs used in combination. A marked G2-M cell cycle arrest with a nearly complete depletion of S phase was associated. The combined treatment triggered an increased apoptosis compared with either drug tested alone. A significant inhibition of tumor growth and microvessel area was obtained in neuroblastoma-bearing mice when treated with vinblastine or rapamycin alone, and a more dramatic effect with the combined treatment, compared with control mice. The therapeutic effectiveness, expressed as increased life span, was statistically improved by the combined therapy, compared with mice treated with either drug tested separately. Histologic evaluation of primary tumors showed that the combined treatment inhibited proliferation and angiogenesis and induced apoptosis. Combined treatment of neuroblastoma cells and neuroblastoma-bearing mice with vinblastine and rapamycin induced the down-modulation of both vascular endothelial growth factor production and vascular endothelial growth factor receptor 2 expression. In the chorioallantoic membrane assay, angiogenesis induced by human neuroblastoma biopsy specimens was significantly inhibited by vinblastine and rapamycin.
Conclusions: These results may be relevant to design new therapeutic strategies against neuroblastoma.
- neuroblastoma
- rapamycin
- vinblastine
- anti-angiogenesis
- combination therapy
Footnotes
↵5 Patrizia Perri, personal communication.
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Grant support: Associazione Italiana per la Ricerca sul Cancro, Fondazione Italiana per la lotta al Neuroblastoma, and Ministry of Health.
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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Note: Supplementary data for this article are available at Clinical Cancer Research Online (http://clincancerres.aacrjournals.org/).
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C. Brignole is a recipient of a Fondazione Italiana Ricerca Cancro fellowship. F. Pastorino, G. Pagnan, L. Longo, and P. Perri are recipients of a Fondazione Italiana per la Lotta al Neuroblastoma fellowship.
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No sponsor(s) have a role in the design of the study; the collection, analysis, and interpretation of the data; the writing of the manuscript; and the decision to submit the manuscript for publication.
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D. Marimpietri and C. Brignole contributed equally to this work and should be considered joint first authors.
- Accepted April 18, 2007.
- Received November 20, 2006.
- Revision received April 2, 2007.
Volume 13, Issue 13
