The interactions of amphiphilic antisense oligonucleotides with serum proteins and their effects on in vitro silencing activity.
Antisense oligonucleotides (AONs) are a class of compounds with high therapeutic potential. One of the challenges facing this platform is the development of effective techniques to achieve cellular delivery. AON conjugates, in which traditional AONs are attached to certain biomolecules, can exhibit improved intracellular bioavailability in the absence of delivery systems. In this study, the lipophilic moieties docosahexaenoic acid, cholesterol, and docosanoic acid (DSA) were conjugated to various phosphorothioated DNA and chemically-modified 2'-fluoro-arabinonucleic acid AONs via an amino-hexanol-linker added to the 5'-end of the molecule. The gene silencing potential of these compounds was evaluated in vitro in the absence or presence of a transfecting agent (polyion complex micelle). Incubation with sub-micromolar concentration of DSA-conjugates could, in the absence of serum proteins, downregulate more than 60% of the targeted mRNA under carrier-free and carrier-loaded delivery methods. Gene silencing activity of carrier-free DSA-conjugates was, however, decreased in a dose-dependent fashion by adding albumin in the transfection medium. Supplementing the medium with free fatty acid prevented the interaction of the DSA-conjugate with albumin, and restored its silencing activity. These findings suggest that strategies aiming at preventing the association of hydrophobized AONs to serum proteins at the site of action may improve their activity.
Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Wolfgang-Pauli Str. 10, 8093 Zurich, Switzerland.
Arnaud E
AE
Felber
Núria
N
Bayó-Puxan
Glen F
GF
Deleavey
Bastien
B
Castagner
Masad J
MJ
Damha
Jean-Christophe
JC
Leroux
D001681:Biological Assay; D045744:Cell Line, Tumor; D024202:Electrophoretic Mobility Shift Assay; D005227:Fatty Acids / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D006801:Humans; D008297:Male; D008823:Micelles; D016376:Oligonucleotides, Antisense / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism*; D013501:Surface-Active Agents / Q000378:metabolism*
D005227:Fatty Acids; D008823:Micelles; D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012709:Serum Albumin; D013501:Surface-Active Agents