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Title: Irradiation promotes Akt-targeting therapeutic gene delivery to the tumor vasculature

Abstract

Purpose: To determine whether radiation-induced increases in nitric oxide (NO) production can influence tumor blood flow and improve delivery of Akt-targeting therapeutic DNA lipocomplexes to the tumor. Methods and Materials: The contribution of NO to the endothelial response to radiation was identified using NO synthase (NOS) inhibitors and endothelial NOS (eNOS)-deficient mice. Reporter-encoding plasmids complexed with cationic lipids were used to document the tumor vascular specificity and the efficacy of in vivo lipofection after irradiation. A dominant-negative Akt gene construct was used to evaluate the facilitating effects of radiotherapy on the therapeutic transgene delivery. Results: The abundance of eNOS protein was increased in both irradiated tumor microvessels and endothelial cells, leading to a stimulation of NO release and an associated increase in tumor blood flow. Transgene expression was subsequently improved in the irradiated vs. nonirradiated tumor vasculature. This effect was not apparent in eNOS-deficient mice and could not be reproduced in irradiated cultured endothelial cells. Finally, we combined low-dose radiotherapy with a dominant-negative Akt gene construct and documented synergistic antitumor effects. Conclusions: This study offers a new rationale to combine radiotherapy with gene therapy, by directly exploiting the stimulatory effects of radiation on NO production by tumor endothelial cells. Themore » preferential expression of the transgene in the tumor microvasculature underscores the potential of such an adjuvant strategy to limit the angiogenic response of irradiated tumors.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [2];  [2];  [3]
  1. Unit of Pharmacology and Therapeutics, Universite Catholique de Louvain Medical School, Brussels (Belgium)
  2. Unit of Biomedical Resonance Imaging, Universite Catholique de Louvain Medical School, Brussels (Belgium)
  3. Unit of Pharmacology and Therapeutics, Universite Catholique de Louvain Medical School, Brussels (Belgium). E-mail: feron@mint.ucl.ac.be
Publication Date:
OSTI Identifier:
20944775
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 67; Journal Issue: 4; Other Information: DOI: 10.1016/j.ijrobp.2006.11.031; PII: S0360-3016(06)03506-1; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BLOOD FLOW; DNA; GENE THERAPY; GENES; IN VIVO; IRRADIATION; LIPIDS; NEOPLASMS; PLASMIDS; PROTEINS; RADIATION DOSES; RADIOTHERAPY; SPECIFICITY; STIMULATION; VASODILATION

Citation Formats

Sonveaux, Pierre, Frerart, Francoise, Bouzin, Caroline, Brouet, Agnes, Wever, Julie de, Jordan, Benedicte F., Gallez, Bernard, and Feron, Olivier. Irradiation promotes Akt-targeting therapeutic gene delivery to the tumor vasculature. United States: N. p., 2007. Web. doi:10.1016/j.ijrobp.2006.11.031.
Sonveaux, Pierre, Frerart, Francoise, Bouzin, Caroline, Brouet, Agnes, Wever, Julie de, Jordan, Benedicte F., Gallez, Bernard, & Feron, Olivier. Irradiation promotes Akt-targeting therapeutic gene delivery to the tumor vasculature. United States. doi:10.1016/j.ijrobp.2006.11.031.
Sonveaux, Pierre, Frerart, Francoise, Bouzin, Caroline, Brouet, Agnes, Wever, Julie de, Jordan, Benedicte F., Gallez, Bernard, and Feron, Olivier. Thu . "Irradiation promotes Akt-targeting therapeutic gene delivery to the tumor vasculature". United States. doi:10.1016/j.ijrobp.2006.11.031.
@article{osti_20944775,
title = {Irradiation promotes Akt-targeting therapeutic gene delivery to the tumor vasculature},
author = {Sonveaux, Pierre and Frerart, Francoise and Bouzin, Caroline and Brouet, Agnes and Wever, Julie de and Jordan, Benedicte F. and Gallez, Bernard and Feron, Olivier},
abstractNote = {Purpose: To determine whether radiation-induced increases in nitric oxide (NO) production can influence tumor blood flow and improve delivery of Akt-targeting therapeutic DNA lipocomplexes to the tumor. Methods and Materials: The contribution of NO to the endothelial response to radiation was identified using NO synthase (NOS) inhibitors and endothelial NOS (eNOS)-deficient mice. Reporter-encoding plasmids complexed with cationic lipids were used to document the tumor vascular specificity and the efficacy of in vivo lipofection after irradiation. A dominant-negative Akt gene construct was used to evaluate the facilitating effects of radiotherapy on the therapeutic transgene delivery. Results: The abundance of eNOS protein was increased in both irradiated tumor microvessels and endothelial cells, leading to a stimulation of NO release and an associated increase in tumor blood flow. Transgene expression was subsequently improved in the irradiated vs. nonirradiated tumor vasculature. This effect was not apparent in eNOS-deficient mice and could not be reproduced in irradiated cultured endothelial cells. Finally, we combined low-dose radiotherapy with a dominant-negative Akt gene construct and documented synergistic antitumor effects. Conclusions: This study offers a new rationale to combine radiotherapy with gene therapy, by directly exploiting the stimulatory effects of radiation on NO production by tumor endothelial cells. The preferential expression of the transgene in the tumor microvasculature underscores the potential of such an adjuvant strategy to limit the angiogenic response of irradiated tumors.},
doi = {10.1016/j.ijrobp.2006.11.031},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 4,
volume = 67,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • Highlights: • siRNA-lipid nanoparticles are solid particles not lipid bilayers with aqueous core. • High, but not low, PEG content can prevent nanoparticle encapsulation of siRNA. • PEG reduces cellular toxicity of cationic nanoparticles in vitro. • PEG reduces zeta potential while improving gene silencing of siRNA nanoparticles. • Kinesin spindle protein can be an effective target for tumor vascular targeting. - Abstract: The ideal siRNA delivery system should selectively deliver the construct to the target cell, avoid enzymatic degradation, and evade uptake by phagocytes. In the present study, we evaluated the importance of polyethylene glycol (PEG) on lipid-based carriermore » systems for encapsulating, and delivering, siRNA to tumor vessels using cellular models. Lipid nanoparticles containing different percentage of PEG were evaluated based on their physical chemical properties, density compared to water, siRNA encapsulation, toxicity, targeting efficiency and gene silencing in vitro. siRNA can be efficiently loaded into lipid nanoparticles (LNPs) when DOTAP is included in the formulation mixture. However, the total amount encapsulated decreased with increase in PEG content. In the presence of siRNA, the final formulations contained a mixed population of particles based on density. The major population which contains the majority of siRNA exhibited a density of 4% glucose, and the minor fraction associated with a decreased amount of siRNA had a density less than PBS. The inclusion of 10 mol% PEG resulted in a greater amount of siRNA associated with the minor fraction. Finally, when kinesin spindle protein (KSP) siRNA was encapsulated in lipid nanoparticles containing a modest amount of PEG, the proliferation of endothelial cells was inhibited due to the efficient knock down of KSP mRNA. The presence of siRNA resulted in the formation of solid lipid nanoparticles when prepared using the thin film and hydration method. LNPs with a relatively modest amount of PEG can sufficiently encapsulate siRNA, improve cellular uptake and the efficiency of gene silencing.« less
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