title: Enhanced cellular uptake of a triplex-forming oligonucleotide by nanoparticle formation in the presence of polypropylenimine dendrimers.
abstract: We used polypropylenimine dendrimers for delivering a 31 nt triplex-forming oligonucleotide (ODN) in breast, prostate and ovarian cancer cell lines, using 32P-labeled ODN. Dendrimers enhanced the uptake of ODN by approximately 14-fold in MDA-MB-231 breast cancer cells, compared with control ODN uptake. Dendrimers exerted their effect in a concentration- and molecular weight-dependent manner, with generation 4 (G-4) dendrimer having maximum efficacy. A similar increase in ODN uptake was found with MCF-7 and SK-BR-3 (breast), LNCaP (prostate) and SK-OV-3 (ovarian) cancer cells. The dendrimers had no significant effect on cell viability at concentrations at which maximum ODN uptake occurred. [3H]Thymidine incorporation showed that complexing the ODN with G-4 significantly increased the growth-inhibitory effect of the ODN. Western blot analysis showed a significant 65% reduction of c-myc protein level in ODN-G-4 treated cells compared with that of ODN-treated/control cells. Gel electrophoretic analysis showed that ODN remained intact in cells even after 48 h of treatment. The hydrodynamic radii of nanoparticles formed from ODN in the presence of the dendrimers were in the range of 130-280 nm, as determined by dynamic laser light scattering. Taken together, our results indicate that polypropylenimine dendrimers might be useful vehicles for delivering therapeutic oligonucleotides in cancer cells.
authors.affiliation: Department of Medicine, Cancer Institute of New Jersey, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ 08903, USA .
authors.forename: Latha M
authors.initials: LM
authors.lastname: Santhakumaran
authors.forename: Thresia
authors.initials: T
authors.lastname: Thomas
authors.forename: T J
authors.initials: TJ
authors.lastname: Thomas
mesh_terms: D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000737:chemistry* / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008297:Male; D036103:Nanotechnology; D009841:Oligonucleotides / Q000737:chemistry* / Q000493:pharmacokinetics; D010316:Particle Size; D010761:Phosphorus Radioisotopes; D011126:Polypropylenes / Q000008:administration & dosage / Q000737:chemistry*; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism
chemical_list: D009841:Oligonucleotides; D010761:Phosphorus Radioisotopes; D011126:Polypropylenes; D016271:Proto-Oncogene Proteins c-myc; C051802:triplex DNA; D004247:DNA