Use of Antisense Vectors and Oligodeoxynucleotides in Neuro-Oncology

Engelhard, Herbert H.; Egli, Martin; Rozental, Jack M.

doi:10.1159/000028665

Cited by 9 publications

(4 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In no type of assay did the DOR-AS-1 LNA-containing oligonucleotides (all-LNA, LNA͞DNA mix-mer, or LNA͞DNA͞ LNA gap-mer) differ from their all-DNA counterparts, and we therefore suggest that the liability of LNA toxicity is minimal in the living rat brain. In contrast, and what is well known (7,8,25), the all-phosphorothioate oligonucleotides induced severe tissue damage, especially when given into parenchyma (Fig. 5).…”

Section: Resultsmentioning

confidence: 62%

“…The latter phenomenon contributes to a toxicity profile that limits many applications (6, 7). For example, when injected into the brain, phosphorothioates can cause severe tissue damage, especially with repeated or prolonged administration schedules (7,8). Such phosphorothioate-induced toxic reactions are thought to be reduced but not absent in second-generation antisense agents, like mixed backbone oligonucleotides (containing phosphorothioates in combination with oligodeoxyribonucleotides or oligoribonucleotides) (9).…”

mentioning

confidence: 99%

“…Although phosphorothioates are markedly more resistant to degrading enzymes than DNA, their DNA-binding capacity (relating to potency when used as antisense agents) is low, and they are well known to cause nonspecific protein binding, largely because of their polyanionic nature. The latter phenomenon contributes to a toxicity profile that limits many applications (6,7). For example, when injected into the brain, phosphorothioates can cause severe tissue damage, especially with repeated or prolonged administration schedules (7,8).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Potent and nontoxic antisense oligonucleotides containing locked nucleic acids

Wahlestedt

Salmi

Good

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

565

416

View full text Add to dashboard Cite

Insufficient efficacy and͞or specificity of antisense oligonucleotides limit their in vivo usefulness. We demonstrate here that a highaffinity DNA analog, locked nucleic acid (LNA), confers several desired properties to antisense agents. Unlike DNA, LNA͞DNA copolymers were not degraded readily in blood serum and cell extracts. However, like DNA, the LNA͞DNA copolymers were capable of activating RNase H, an important antisense mechanism of action. In contrast to phosphorothioate-containing oligonucleotides, isosequential LNA analogs did not cause detectable toxic reactions in rat brain. LNA͞DNA copolymers exhibited potent antisense activity on assay systems as disparate as a G-protein-coupled receptor in living rat brain and an Escherichia coli reporter gene. LNA-containing oligonucleotides will likely be useful for many antisense applications.A ntisense oligonucleotides designed according to straightforward base-pairing rules have been useful in functional genomics efforts, and there also has been recent clinical progress in developing antisense drugs (1-5). The key objective in the field, however, remains the identification of oligonucleotide analogs that provide the possibility to achieve high in vivo efficacy in the absence of significant toxicity (1-3).To date, all human antisense studies, as well as the vast majority of studies on other species, have relied on the use of phosphorothioate DNA analogs (where one nonbridging phosphate oxygen has been replaced). Although phosphorothioates are markedly more resistant to degrading enzymes than DNA, their DNA-binding capacity (relating to potency when used as antisense agents) is low, and they are well known to cause nonspecific protein binding, largely because of their polyanionic nature. The latter phenomenon contributes to a toxicity profile that limits many applications (6, 7). For example, when injected into the brain, phosphorothioates can cause severe tissue damage, especially with repeated or prolonged administration schedules (7,8). Such phosphorothioate-induced toxic reactions are thought to be reduced but not absent in second-generation antisense agents, like mixed backbone oligonucleotides (containing phosphorothioates in combination with oligodeoxyribonucleotides or oligoribonucleotides) (9).Interestingly, conformational restriction has been successfully applied in recent years to the design of high-affinity oligonucleotides. Several analogs containing bi-and tricyclic carbohydrate moieties have displayed enhanced duplex stability (10-20) and most notably so locked nucleic acids (LNA) (Fig. 1). LNA induces unprecedented increases in the thermal stability (melting temperature, T m ) of duplexes toward complementary DNA and RNA (⌬T m ͞LNA monomer ϭ ϩ 3 to ϩ 11°C compared with the corresponding DNA reference). By virtue of their bicyclic structure, the furanose ring of the LNA monomers is locked in a 3Ј-endo conformation, thus structurally mimicking the standard RNA monomers. Moreover, LNA͞LNA duplex formation has been shown to constitute the most stable...

show abstract

Section: Resultsmentioning

confidence: 62%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Potent and nontoxic antisense oligonucleotides containing locked nucleic acids

Wahlestedt

Salmi

Good

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

565

416

View full text Add to dashboard Cite

show abstract

“…Successful application of ASOs modified by phosophothioate bonds was reported for both chronic and acute treatment protocols in the brain (Jan et al, 2015 ), each achieving moderate levels of target knockdown. However, the higher dose and time required for phosphorothioate ASOs to produce efficient knockdown has been associated with neural tissue damage (Engelhard, 1998 ; Engelhard et al, 1998 ), thereby limiting their utility. Alternative backbone modifications, such as phosphoramidate bonds, have also been investigated, but their in vivo effectiveness in the brain is only a beginning to be investigated (Crooke, 2008 ).…”

Section: Disrupting Gene Expression In the Brain Without The Need Formentioning

confidence: 99%

Advanced In vivo Use of CRISPR/Cas9 and Anti-sense DNA Inhibition for Gene Manipulation in the Brain

et al. 2016

View full text Add to dashboard Cite

Gene editing tools are essential for uncovering how genes mediate normal brain–behavior relationships and contribute to neurodegenerative and neuropsychiatric disorders. Recent progress in gene editing technology now allows neuroscientists unprecedented access to edit the genome efficiently. Although many important tools have been developed, here we focus on approaches that allow for rapid gene editing in the adult nervous system, particularly CRISPR/Cas9 and anti-sense nucleotide-based techniques. CRISPR/Cas9 is a flexible gene editing tool, allowing the genome to be manipulated in diverse ways. For instance, CRISPR/Cas9 has been successfully used to knockout genes, knock-in mutations, overexpress or inhibit gene activity, and provide scaffolding for recruiting specific epigenetic regulators to individual genes and gene regions. Moreover, the CRISPR/Cas9 system may be modified to target multiple genes at one time, affording simultaneous inhibition and overexpression of distinct genetic targets. Although many of the more advanced applications of CRISPR/Cas9 have not been applied to the nervous system, the toolbox is widely accessible, such that it is poised to help advance neuroscience. Anti-sense nucleotide-based technologies can be used to rapidly knockdown genes in the brain. The main advantage of anti-sense based tools is their simplicity, allowing for rapid gene delivery with minimal technical expertise. Here, we describe the main applications and functions of each of these systems with an emphasis on their many potential applications in neuroscience laboratories.

show abstract

TGF-β2 inhibition augments the effect of tumor vaccine and improves the survival of animals with pre-established brain tumors

Liu

Wang

Kleinschmidt-DeMasters

et al. 2006

J Neurooncol

View full text Add to dashboard Cite

TGF-beta2 secretion by high grade gliomas has been implicated as one of the major factors contributing to tumor growth, alterations in the host immune response to tumor, and failure of gliomas to respond to current immunotherapy strategies. We hypothesized that targeted delivery and inhibition of TGF-beta2 by TGF-beta2 antisense oligonucleotides (AS-ODNs) would overcome tumor-induced immunosuppression and enhance the capacity of tumor vaccines to eradicate established brain tumors. Utilizing the mRNA sequences of TGF-beta2, specific AS-ODNs were constructed and tested for their ability to inhibit TGF-beta2 production in 9L glioma cells. The effect of combining local intracranial administration of antisense ODNs with systemic tumor vaccine was examined. Fisher 344 rats were vaccinated subcutaneously with irradiated 9L tumor cells 3 days after intracranial tumor implantation. Four days after vaccination, ODNs were administered into the tumor mass and survival was followed. ODNs delivered locally distributed widely within the brain tumor mass and inhibited TGF-beta2 expression. Survival of tumor-bearing rats treated with the combination of local antisense and systemic tumor vaccine was significantly enhanced (mean survival time (MST): 48.0 days). In contrast, MST for animals treated with nonsense plus vaccine, vaccine alone, antisense alone or PBS showed no survival advantage and no statistical differences between groups (33.5 days, 29.0 days, 37.5 days, and 31.5 days, respectively). Our data supports the hypothesis that local administration of antisense TGF-beta2 ODNs combined with systemic vaccination can increase efficacy of immunotherapy and is a novel, potentially clinically applicable, strategy for high-grade glioma treatment.

show abstract

Use of Antisense Vectors and Oligodeoxynucleotides in Neuro-Oncology

Cited by 9 publications

References 69 publications

Potent and nontoxic antisense oligonucleotides containing locked nucleic acids

Potent and nontoxic antisense oligonucleotides containing locked nucleic acids

Advanced In vivo Use of CRISPR/Cas9 and Anti-sense DNA Inhibition for Gene Manipulation in the Brain

TGF-β2 inhibition augments the effect of tumor vaccine and improves the survival of animals with pre-established brain tumors

Contact Info

Product

Resources

About