Utilization of unlocked nucleic acid (UNA) to enhance siRNA performance in vitro and in vivo

TY - JOUR

T1 - Utilization of unlocked nucleic acid (UNA) to enhance siRNA performance in vitro and in vivo

AU - Laursen, Maria B

AU - Pakula, Malgorzata M

AU - Gao, Shan

AU - Fluiter, Kees

AU - Mook, Olaf R

AU - Baas, Frank

AU - Langklaer, Niels

AU - Wengel, Suzy L

AU - Wengel, Jesper

AU - Kjems, Jørgen

AU - Bramsen, Jesper B

N1 - Paper id:: 10.1039/b918869j

PY - 2010

Y1 - 2010

N2 - Small interfering RNAs (siRNAs) are now established as a favourite tool to reduce gene expression by RNA interference (RNAi) in mammalian cell culture. However, limitations in potency, duration, delivery and specificity of the gene knockdown (KD) are still major obstacles that need further addressing. Recent studies have successfully improved siRNA performance by the introduction of several types of chemical modifications. Here we explore the effect of incorporating unlocked nucleic acid (UNA) into siRNA designs. The acyclic UNA monomers lack the C2'-C3'-bond of the RNA ribose ring and additively decrease nucleic acid duplex thermostability. We show that UNA-modifications of siRNAs are compatible with efficient RNAi and can improve siRNA performance both in vitro and in vivo. In particular, we find that the destabilizing properties of UNA are well suited to enhance the potency of siRNAs which are heavily modified by other chemical modifications such as locked nucleic acid (LNA), C4'hydroxymethyl-DNA (HM), 2'-O-methyl-RNA (OMe), DNA and 2'-Flouro-DNA (F). Interestingly, we find that naked, but UNA-modified siRNAs have dramatically increased biostability in mice and can induce potent KD in a xenograft model of human pancreas cancer. Hereby UNA constitutes an important type of chemical modification for future siRNA designs.

AB - Small interfering RNAs (siRNAs) are now established as a favourite tool to reduce gene expression by RNA interference (RNAi) in mammalian cell culture. However, limitations in potency, duration, delivery and specificity of the gene knockdown (KD) are still major obstacles that need further addressing. Recent studies have successfully improved siRNA performance by the introduction of several types of chemical modifications. Here we explore the effect of incorporating unlocked nucleic acid (UNA) into siRNA designs. The acyclic UNA monomers lack the C2'-C3'-bond of the RNA ribose ring and additively decrease nucleic acid duplex thermostability. We show that UNA-modifications of siRNAs are compatible with efficient RNAi and can improve siRNA performance both in vitro and in vivo. In particular, we find that the destabilizing properties of UNA are well suited to enhance the potency of siRNAs which are heavily modified by other chemical modifications such as locked nucleic acid (LNA), C4'hydroxymethyl-DNA (HM), 2'-O-methyl-RNA (OMe), DNA and 2'-Flouro-DNA (F). Interestingly, we find that naked, but UNA-modified siRNAs have dramatically increased biostability in mice and can induce potent KD in a xenograft model of human pancreas cancer. Hereby UNA constitutes an important type of chemical modification for future siRNA designs.

KW - Animals

KW - Cell Line, Tumor

KW - Humans

KW - Liver Neoplasms

KW - Mice

KW - Molecular Structure

KW - RNA Interference

KW - RNA Stability

KW - RNA, Small Interfering

KW - Xenograft Model Antitumor Assays

U2 - 10.1039/b918869j

DO - 10.1039/b918869j

M3 - Journal article

C2 - 20567772

SN - 1742-206X

VL - 6

SP - 862

EP - 870

JO - Molecular BioSystems

JF - Molecular BioSystems

IS - 5

ER -