title: Cancer-specific transgene expression mediated by systemic injection of nanoparticles.
abstract: The lack of safe and efficient systemic gene delivery vectors has largely reduced the potential of gene therapy in the clinic. Previously, we have reported that polypropylenimine dendrimer PPIG3/DNA nanoparticles are capable of tumor transfection upon systemic administration in tumor-bearing mice. To be safely applicable in the clinic, it is crucial to investigate the colloidal stability of nanoparticles and to monitor the exact biodistribution of gene transfer in the whole body of the live subject. Our biophysical characterization shows that dendrimers, when complexed with DNA, are capable of forming spontaneously in solution a supramolecular assembly that possesses all the features required to diffuse in experimental tumors through the enhanced permeability and retention effect. We show that these nanoparticles are of sizes ranging from 33 to 286 nm depending on the DNA concentration, with a colloidal stable and well-organized fingerprint-like structure in which DNA molecules are condensed with an even periodicity of 2.8 nm. Whole-body nuclear imaging using small-animal nano-single-photon emission computed tomography/computer tomography scanner and the human Na/I symporter (NIS) as reporter gene shows unique and highly specific tumor targeting with no detection of gene transfer in any of the other tissues of tumor-bearing mice. Tumor-selective transgene expression was confirmed by quantitative reverse transcription-PCR at autopsy of scanned animals, whereas genomic PCR showed that the tumor sites are the predominant sites of nanoparticle accumulation. Considering that NIS imaging of transgene expression has been recently validated in humans, our data highlight the potential of these nanoparticles as a new formulation for cancer gene therapy.
authors.affiliation: Centre for Molecular Oncology, Queen Mary's School of Medicine and Dentistry, London, United Kingdom.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Chisholm
authors.forename: Georges
authors.initials: G
authors.lastname: Vassaux
authors.forename: Pilar
authors.initials: P
authors.lastname: Martin-Duque
authors.forename: Raphael
authors.initials: R
authors.lastname: Chevre
authors.forename: Olivier
authors.initials: O
authors.lastname: Lambert
authors.forename: Bruno
authors.initials: B
authors.lastname: Pitard
authors.forename: Andrew
authors.initials: A
authors.lastname: Merron
authors.forename: Mark
authors.initials: M
authors.lastname: Weeks
authors.forename: Jerome
authors.initials: J
authors.lastname: Burnet
authors.forename: Inge
authors.initials: I
authors.lastname: Peerlinck
authors.forename: Ming-Shen
authors.initials: MS
authors.lastname: Dai
authors.forename: Ghassan
authors.initials: G
authors.lastname: Alusi
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Mather
authors.forename: Katherine
authors.initials: K
authors.lastname: Bolton
authors.forename: Ijeoma F
authors.initials: IF
authors.lastname: Uchegbu
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Schatzlein
authors.forename: Patrick
authors.initials: P
authors.lastname: Baril
mesh_terms: D000818:Animals; D003102:Colloids / Q000737:chemistry; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D050091:Dendrimers / Q000737:chemistry; D004355:Drug Stability; D005260:Female; D005583:Fourier Analysis; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D006801:Humans; D008027:Light; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008819:Mice, Nude; D046529:Microscopy, Electron, Transmission / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry*; D010957:Plasmids / Q000737:chemistry / Q000235:genetics; D011126:Polypropylenes / Q000737:chemistry*; D012542:Scattering, Radiation; D014183:Transplantation, Heterologous
chemical_list: D003102:Colloids; D050091:Dendrimers; D011126:Polypropylenes; C443641:poly(propyleneimine); D004247:DNA