Antisense oligonucleotides targeting angiogenic factors as potential cancer therapeutics

Cancer is one of the leading causes of death worldwide and conventional cancer therapies such as surgery, chemotherapy and radiotherapy do not address the underlying molecular pathologies, leading to inadequate treatment and tumour recurrence. Angiogenic factors, such as EGF, PDGF, bFGF, TGF-β, TGF-α, VEGF, Endoglin and Angiopoietins play important roles in regulating tumour development and metastasis, and serve as potential targets for developing cancer therapeutics. Nucleic acid-based therapeutic strategies have received significant attention in the last two decades, and antisense oligonucleotide-mediated intervention is a prominent therapeutic approach for targeted manipulation of gene expression. Clinical benefits of antisense oligonucleotides have been recognised by the US Food and Drug Administration, with full or conditional approval of Vitravene, Kynamro, Exondys51 and Spinraza. Herein, we review the scope of antisense oligonucleotides that target angiogenic factors towards tackling solid cancers

Consequences of making the inactive active through changes in antisense oligonucleotide chemistries

Antisense oligonucleotides are short, single-stranded nucleic acid analogues that can interfere with pre-messenger RNA (pre-mRNA) processing and induce excision of a targeted exon from the mature transcript. When developing a panel of antisense oligonucleotides to skip every dystrophin exon, we found great variation in splice switching efficiencies, with some antisense oligonucleotides ineffective, even when directed to canonical splice sites and transfected into cells at high concentrations. In this study, we re-evaluated some of these ineffective antisense oligonucleotide sequences after incorporation of locked nucleic acid residues to increase annealing potential. Antisense oligonucleotides targeting exons 16, 23, and 51 of human DMD transcripts were synthesized as two different chemistries, 2 '-O-methyl modified bases on a phosphorothioate backbone or mixmers containing several locked nucleic acid residues, which were then transfected into primary human myotubes, and DMD transcripts were analyzed for exon skipping. The ineffective 2 '-O-methyl modified antisense oligonucleotides induced no detectable exon skipping, while all corresponding mixmers did induce excision of the targeted exons. Interestingly, the mixmer targeting exon 51 induced two unexpected transcripts arising from partial skipping of exon 51 with retention of 95 or 188 bases from the 5 ' region of exon 51. These results indicated that locked nucleic acid/2 '-O-methyl mixmers are more effective at inducing exon skipping, however, this improvement may come at the cost of activating alternative cryptic splice sites and off-target effects on gene expression

Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

Rational design of short locked Nucleic Acid-Modified 2′- O -Methyl antisense oligonucleotides for efficient exon-skipping in vitro

Locked nucleic acid is a prominent nucleic acid analog with unprecedented target binding affinity to cDNA and RNA oligonucleotides and shows remarkable stability against nuclease degradation. Incorporation of locked nucleic acid nucleotides into an antisense oligonucleotide (AO) sequence can reduce the length required without compromising the efficacy. In this study, we synthesized a series of systematically truncated locked nucleic acid-modified 2′-O-methyl AOs on a phosphorothioate (PS) backbone that were designed to induce skipping exon 23 from the dystrophin transcript in H-2Kb-tsA58 mdx mouse myotubes in vitro. The results clearly demonstrated that shorter AOs (16- to 14-mer) containing locked nucleic acid nucleotides efficiently induced dystrophin exon 23 skipping compared with the corresponding 2′-O-methyl AOs. Our remarkable findings contribute significantly to the existing knowledge about the designing of short LNA-modified oligonucleotides for exon-skipping applications, which will help reduce the cost of exon-skipping AOs and potential toxicities, particularly the 2′-OMe-based oligos, by further reducing the length of AOs

The emperor's new dystrophin: Finding sense in the noise

Targeted dystrophin exon removal is a promising therapy for Duchenne muscular dystrophy (DMD); however, dystrophin expression in some reports is not supported by the associated data. As in the account of ‘The Emperor's New Clothes’, the validity of such claims must be questioned, with critical re-evaluation of available data. Is it appropriate to report clinical benefit and induction of dystrophin as dose dependent when the baseline is unclear? The inability to induce meaningful levels of dystrophin does not mean that dystrophin expression as an end point is irrelevant, nor that induced exon skipping as a strategy is flawed, but demands that drug safety and efficacy, and study parameters be addressed, rather than questioning the strategy or the validity of dystrophin as a biomarker

Smart functional nucleic acid chimeras: Enabling tissue specific RNA targeting therapy

A major obstacle for effective utilization of therapeutic oligonucleotides such as siRNA, antisense, antimiRs etc. is to deliver them specifically to the target tissues. Toward this goal, nucleic acid aptamers are re-emerging as a prominent class of biomolecules capable of delivering target specific therapy and therapeutic monitoring by various molecular imaging modalities. This class of short oligonucleotide ligands with high affinity and specificity are selected from a large nucleic acid pool against a molecular target of choice. Poor cellular uptake of therapeutic oligonucleotides impedes gene-targeting efficacy in vitro and in vivo. In contrast, aptamer-oligonucleotide chimeras have shown the capacity to deliver siRNA, antimiRs, small molecule drugs etc. toward various targets and showed very promising results in various studies on different diseases models. However, to further improve the bio-stability of such chimeric conjugates, it is important to introduce chemically-modified nucleic acid analogs. In this review, we highlight the applications of nucleic acid aptamers for target specific delivery of therapeutic oligonucleotides

Antisense oligonucleotide development for the treatment of muscular dystrophies

Introduction: Depending upon the chemistry and annealing target, antisense oligonucleotides can be used to modify gene expression through several distinct modes of action. Originally used to down-regulate gene expression through specific induction of RNAse-H cleavage of an mRNA, antisense oligonucleotides can be designed to block initiation of translation, manipulate pre-mRNA processing, silence gene expression or act as antagomirs to sequester miRNAs. Area covered: In this review, we describe currently available antisense oligonucleotide chemistries, briefly summarize mechanisms of action, potential applications to neuromuscular diseases and discuss the most clinically advanced antisense oligonucleotide application to muscular dystrophy, restoration of functional dystrophin expression in Duchenne muscular dystrophy. Expert opinion: Antisense oligonucleotide chemistries that are excellent research tools may not necessarily be appropriate or safe for clinical application. Hypothesis-driven translational research demands that changes in target gene expression at both the RNA and protein levels, after administration of the antisense oligonucleotide, should be readily detectable. In ongoing clinical studies on Duchenne muscular dystrophy, it is only the phosphorodiamidate morpholino oligomer that results in unequivocal increases in muscle dystrophin. It is our opinion that these compounds could present new therapeutic opportunities for a number of otherwise untreatable conditions

Knowledge of spatial relations

SIGLELD:8318.172(SSRC-HR--7059) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Locked nucleic acid-modified antisense oligonucleotides for enhanced exon skipping in Duchenne muscular dystrophy

Oligonucleotides have gained significant interest in recent years towards the development of therapeutics and diagnostics against several diseases. The first such drug to enter the clinic has been Vitravene, used for the treatment of cytomegaloviral retinitis. Later, Macugen was approved for the treatment of macular degeneration, and very recently Kynamro against familial hypercholesterolemia. Oligonucleotides composed natural nucleotide monomers pose severe limitations, including poor nuclease resistance and decreased target binding affinity, and are not suitable for therapeutic developments. To overcome these challenges, chemically‐modified nucleic acid analogues are used. One of the most prominent and successful analogues is locked nucleic acid (LNA) [1,2]. We are developing LNA and other chemically‐modified therapeutic oligonucleotides to improve the efficacy and pharmacokinetic properties. Very recently, we have investigated the potential of LNA‐modified antisense oligonucleotides (LNA AOs) for exon skipping in Duchenne muscular dystrophy (DMD) [3]. LNA AOs were designed in combination with 2'‐OMe‐modified RNA nucleotides (20mer and a truncated 18mer LNA/OMe AOs) for targeting exon 23 of the dystrophin gene in mouse (mdx mouse with exon 23 point mutation) primary myoblast cells. A fully‐modified 20mer 2'OMe AOs were also used for comparison. The results showed that LNA‐modified AOs are highly efficient in exon 23 skipping. Notably, the truncated 18mer LNA/OMe AO also induced efficient skipping of exon 23. These preliminary results clearly indicate that the development of highly potent LNA AOs in combination with various other chemistries could substantially improve the accuracy and efficiency of exon skipping