title: The effect of nanoparticle size and NLS density on nuclear targeting in cancer and normal cells; impaired nuclear import and aberrant nanoparticle intracellular trafficking in glioma.
abstract: The cell nucleus is an interesting target in many diseases with particular interest in cancer. Previously, nuclear targeted small and large chitosan nanoparticles (S-NPs≈25nm, and L-NPs≈150nm respectively), modified with low, intermediate and high densities of NLS (L-NLS, I-NLS and H-NLS) were developed and assessed in L929 fibroblasts. However, to evade apoptosis and stimulate tumor growth cancer cells are capable of manipulating the nuclear-cytoplasmic transport on many levels, making NPs that are capable of nuclear targeting in normal cells incapable of doing so in cancer. For such reason, here, the nuclear delivery efficiency of S-NPs and L-NPs was assessed as a function of their NLS density in cancer and non-cancer cells. For S-NPs, in all cells tested, NLS was unnecessary for nuclear delivery; unmodified S-NPs showed higher nuclear delivery than NLS-S-NPs due to their ability to gain nuclear entry in a passive manner. For L-NPs, L-NLS-L-NPs showed ≈ 8.5, 33, 1.8 and 7.2 fold higher nuclear deliveries than H-NLS-L-NPs in L929 fibroblasts, primary human fibroblasts, HEK 293 and lung cancer cells, respectively. In glioma however, unmodified L-NPs showed highest nuclear delivery, whereas NLS-L-NPs were retained in the cytoplasm. Experiments conducted in the presence of inhibitors of the classical nuclear import pathway indicated that due to overexpression of importin α, classical nuclear import in glioma is impaired leading to aberrant NP intracellular trafficking and nuclear import.
authors.affiliation: Department of Pharmaceutics, University of Bonn, Bonn 53121, Germany; Department of Chemistry, The American University in Cairo, Cairo 11835, Egypt. Electronic address: salma.tammam@gmail.com.
authors.forename: Salma N
authors.initials: SN
authors.lastname: Tammam
authors.affiliation: Department of Chemistry, The American University in Cairo, Cairo 11835, Egypt.
authors.forename: Hassan M E
authors.initials: HME
authors.lastname: Azzazy
authors.affiliation: Department of Pharmaceutics, University of Bonn, Bonn 53121, Germany; FDE (EA4267), University of Burgundy/Franche-Comté, Besançon 25000, France.
authors.forename: Alf
authors.initials: A
authors.lastname: Lamprecht
mesh_terms: D001692:Biological Transport; D002460:Cell Line; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D048271:Chitosan / Q000008:administration & dosage* / Q000737:chemistry; D005347:Fibroblasts / Q000378:metabolism; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D019913:Nuclear Localization Signals; D010316:Particle Size
chemical_list: D019913:Nuclear Localization Signals; D048271:Chitosan
keywords: Active targeting; Cancer; Chitosan nanoparticles; Glioma; Importin α; Nuclear delivery; Nuclear localization sequence