title: Effective non-viral delivery of siRNA to acute myeloid leukemia cells with lipid-substituted polyethylenimines.
abstract: Use of small interfering RNA (siRNA) is a promising approach for AML treatment as the siRNA molecule can be designed to specifically target proteins that contribute to aberrant cell proliferation in this disease. However, a clinical-relevant means of delivering siRNA molecules must be developed, as the cellular delivery of siRNA is problematic. Here, we report amphiphilic carriers combining a cationic polymer (2 kDa polyethyleneimine, PEI2) with lipophilic moieties to facilitate intracellular delivery of siRNA to AML cell lines. Complete binding of siRNA by the designed carriers was achieved at a polymer:siRNA ratio of ≈ 0.5 and led to siRNA/polymer complexes of ≈ 100 nm size. While the native PEI2 did not display cytotoxicity on AML cell lines THP-1, KG-1 and HL-60, lipid-modification on PEI2 slightly increased the cytotoxicity, which was consistent with increased interaction of polymers with cell membranes. Cellular delivery of siRNA was dependent on the nature of lipid substituent and the extent of lipid substitution, and varied among the three AML cell lines used. Linoleic acid-substituted polymers performed best among the prepared polymers and gave a siRNA delivery equivalent to better performing commercial reagents. Using THP-1 cells and a reporter (GFP) and an endogenous (CXCR4) target, effective silencing of the chosen targets was achieved with 25 to 50 nM of siRNA concentrations, and without adversely affecting subsequent cell growth. We conclude that lipid-substituted PEI2 can serve as an effective delivery of siRNA to leukemic cells and could be employed in molecular therapy of leukemia.
authors.affiliation: Department of Chemical & Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Breanne
authors.initials: B
authors.lastname: Landry
authors.forename: Hamidreza Montazeri
authors.initials: HM
authors.lastname: Aliabadi
authors.forename: Anuja
authors.initials: A
authors.lastname: Samuel
authors.forename: Hilal
authors.initials: H
authors.lastname: Gül-Uludağ
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Jiang
authors.forename: Olaf
authors.initials: O
authors.lastname: Kutsch
authors.forename: Hasan
authors.initials: H
authors.lastname: Uludağ
mesh_terms: D016923:Cell Death; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000235:genetics; D015870:Gene Expression; D015973:Gene Expression Regulation, Leukemic; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007202:Indicators and Reagents; D020128:Inhibitory Concentration 50; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D011094:Polyethyleneimine / Q000737:chemistry*; D034741:RNA, Small Interfering / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism; D044967:Serum / Q000378:metabolism; D013696:Temperature; D014343:Trypan Blue; D014780:Viruses / Q000378:metabolism
chemical_list: C527276:CXCR4 protein, human; D007202:Indicators and Reagents; D008055:Lipids; D034741:RNA, Small Interfering; D019718:Receptors, CXCR4; D049452:Green Fluorescent Proteins; D011094:Polyethyleneimine; D014343:Trypan Blue