Perspectives on Chemistry and Therapeutic Applications of Locked Nucleic Acid (LNA)

Kaur, Harleen; Babu, B. Ravindra; Maiti, Souvik

doi:10.1021/cr050266u

Cited by 269 publications

(230 citation statements)

References 167 publications

Supporting

Mentioning

222

Contrasting

Unclassified

Order By: Relevance

“…Clinical trials on chronically HCV-infected patients show that modified ASOs targeting HCV can result in Ͼ2-log-unit decreases in viral loads, although the mechanism driving clinical antiviral activity has yet to be fully validated as antisense (14,28,33). Moreover, locked nucleic acid (LNA) represents a new generation of ASOs with improved affinity of binding to RNA targets, increased sequence specificity, greater biostability against nucleases, and reportedly lower toxicity (3,15,22,37,40).HCV is a positive-strand RNA virus with a linear genome of ϳ9,500 nucleotides (nt). Different isolates show considerable nucleotide variability, leading to the division of HCV genomes into many different genotypes and subtypes, including the most clinically relevant HCV genotypes, 1a and 1b.…”

mentioning

confidence: 99%

Selection, Optimization, and Pharmacokinetic Properties of a Novel, Potent Antiviral Locked Nucleic Acid-Based Antisense Oligomer Targeting Hepatitis C Virus Internal Ribosome Entry Site

Laxton

Brady

Moschos

et al. 2011

Antimicrob Agents Chemother

View full text Add to dashboard Cite

We have screened 47 locked nucleic acid (LNA) antisense oligonucleotides (ASOs) targeting conserved (>95% homology) sequences in the hepatitis C virus (HCV) genome using the subgenomic HCV replicon assay and generated both antiviral (50% effective concentration [EC 50 ]) and cytotoxic (50% cytotoxic concentration [CC 50 ]) dose-response curves to allow measurement of the selectivity index (SI). This comprehensive approach has identified an LNA ASO with potent antiviral activity (EC 50 ‫؍‬ 4 nM) and low cytotoxicity (CC 50 >880 nM) targeting the 25-to 40-nucleotide region (nt) of the HCV internal ribosome entry site (IRES) containing the distal and proximal miR-122 binding sites. LNA ASOs targeting previously known accessible regions of the IRES, namely, loop III and the initiation codon in loop IV, had poor SI values. We optimized the LNA ASO sequence by performing a 1-nucleotide walk through the 25-to 40-nt region and show that the boundaries for antiviral efficacy are extremely precise. Furthermore, we have optimized the format for the LNA ASO using different gapmer and mixomer patterns and show that RNase H is required for antiviral activity. We demonstrate that RNase H-refractory ASOs targeting the 25-to 40-nt region have no antiviral effect, revealing important regulatory features of the 25-to 40-nt region and suggesting that RNase H-refractory LNA ASOs can act as potential surrogates for proviral functions of miR-122. We confirm the antisense mechanism of action using mismatched LNA ASOs. Finally, we have performed pharmacokinetic experiments to demonstrate that the LNA ASOs have a very long half-life (>5 days) and attain hepatic maximum concentrations >100 times the concentration required for in vitro antiviral activity.Hepatitis C virus (HCV) infection is a major cause of liver disease, with Ͼ170 million infected people worldwide being at risk from liver failure and hepatocarcinoma. Current standard of care (SOC) using pegylated alpha 2a interferon (IFN-␣2a)-ribavirin is failing 40 to 50% of treated HCV patients, so new therapies are urgently required. New directly acting antiviral therapies for hepatitis C are becoming available, but these will eventually fail many HCV patients due to emerging drugresistant mutations in HCV strains (6, 7). HCV genomic RNA is an attractive antiviral target because it holds genetic information for viral proteins and contains regions of highly conserved sequence required for HCV replication/translation. Many groups have identified antisense oligonucleotides (ASOs) capable of inhibiting HCV RNA replication and viral polyprotein synthesis in vitro. Clinical trials on chronically HCV-infected patients show that modified ASOs targeting HCV can result in Ͼ2-log-unit decreases in viral loads, although the mechanism driving clinical antiviral activity has yet to be fully validated as antisense (14,28,33). Moreover, locked nucleic acid (LNA) represents a new generation of ASOs with improved affinity of binding to RNA targets, increased sequence specificity, greater biostability ag...

show abstract

mentioning

confidence: 99%

Selection, Optimization, and Pharmacokinetic Properties of a Novel, Potent Antiviral Locked Nucleic Acid-Based Antisense Oligomer Targeting Hepatitis C Virus Internal Ribosome Entry Site

Laxton

Brady

Moschos

et al. 2011

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…1A). Extensive investigations suggested that substitution of a single LNA base with natural analogues substantially increases the melting temperature (Kaur et al, 2007). Therefore, we hypothesized that a fully modified oligo duplex with LNA and 2¢OMe would be characterized by superior thermodynamic and biochemical properties.…”

Section: Design and Characterization Of Oligosmentioning

confidence: 99%

“…These oligomers are widely being used in antisense technology, DNAzymes, and decoy oligonucleotides and show a great potential to be used in pretargeting systems (Kaur et al, 2007;Moschos et al, 2011). LNA inherently shows excellent thermal stability, affinity, nuclease stability, and mismatch discrimination when hybridized with RNA or DNA.…”

mentioning

confidence: 99%

A Self-Assembling Short Oligonucleotide Duplex Suitable for Pretargeting

Mallikaratchy

Gardner

Nordstrøm

et al. 2013

Nucleic Acid Therapeutics

View full text Add to dashboard Cite

Monoclonal antibodies (mAbs) have naturally evolved as suitable, high affinity and specificity targeting molecules. However, the large size of full-length mAbs yields poor pharmacokinetic properties. A solution to this issue is the use of a multistep administration approach, in which the slower clearing mAb is administered first and allowed to reach the target site selectively, followed by administration of a rapidly clearing small molecule carrier of the cytotoxic or imaging ligand, which bears a cognate receptor for the mAb. Here, we introduce a novel pretargetable RNA based system comprised of locked nucleic acids (LNA) and 2¢O-Methyloligoribonucleotides (2¢OMe-RNA). The duplex shows fast hybridization, high melting temperatures, excellent affinity, and high nuclease stability in plasma. Using a prototype model system with rituximab conjugated to 2¢OMe-RNA (oligo), we demonstrate that LNA-based complementary strand (c-oligo) effectively hybridizes with rituximab-oligo, which is slowly circulating in vivo, despite the high clearance rates of c-oligo.

show abstract

“…[10][11][12][13][14][15] Locked nucleic acid (LNA, Fig. 1), which is a conformationally restricted RNA mimic displaying unprecedented binding affinities towards complementary single stranded RNA or DNA, [16][17][18][19] is a promising modification for AON applications, [20][21][22] and is currently being utilized in various genomic technologies. [23][24][25][26] Introduction of consecutive LNA monomers from the 3 0 -end of an AON efficiently protects against 3 0 -exonucleolytic degradation, 16 whereas isolated LNA monomers in DNA/LNA chimeric AONs offer no significant protection.…”

Section: Introductionmentioning

confidence: 99%