Relevant bibliographies by topics / Oligonucleotidi antisenso / Dissertations / Theses

Dissertations / Theses on the topic 'Oligonucleotidi antisenso'

To see the other types of publications on this topic, follow the link: Oligonucleotidi antisenso.
Author: Grafiati
Published: 10 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Oligonucleotidi antisenso.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Lombardini, Lorenza <1982&gt. "Valutazione preclinica di oligonucleotidi antisenso come nuovo approccio terapeutico specifico per le leucemie acute con riarrangiamenti di MLL." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3238/1/Lombardini_Lorenza_Tesi.pdf.

Full text
Abstract:
Le Leucemie Acute Mieloidi di sottotipo FAB M4 e M5, le Leucemie Acute Linfoblastiche e le Leucemie Bifenotipiche sono frequentemente caratterizzate da traslocazioni del gene 11q23/MLL con formazione di oncogeni di fusione e produzione di oncoproteine che inducono la trasformazione neoplastica. Tali leucemie con riarrangiamenti di 11q23/MLL sono caratterizzate da prognosi infausta e scarsa responsività alle terapie convenzionali. Data la necessità di trovare terapie efficaci per le leucemie con traslocazione di MLL, in questo lavoro di ricerca sono stati progettati, caratterizzati e validati siRNA per il silenziamento genico degli oncogeni di fusione di MLL, con lo scopo di valutare il ripristino delle normali funzionalità di differenziamento cellulare e l’arresto della proliferazione neoplastica. Sono stati progettati siRNA specifici per gli oncogeni di fusione di MLL, sia per le regioni conservate nei diversi oncogeni di fusione, sia a livello del punto di fusione (breakpoint), sia per le regioni sui geni partner. I siRNA sono stati valutati su linee cellulari contenenti diverse traslocazioni del gene MLL. Il silenziamento è stato valutato sia a livello cellulare in termini di riduzione della capacità proliferativa e del numero delle cellule leucemiche, sia a livello molecolare tramite l’analisi della diminuzione dell’mRNA degli oncogeni di fusione di MLL. E’ stata valutata la diminuzione delle oncoproteine di fusione di MLL in seguito a trattamento con siRNA. E’ stata analizzata la variazione dell’espressione di geni dipendenti da MLL in seguito a trattamento con siRNA. Sono stati messi a punto modelli murini bioluminescenti di leucemie acute con traslocazioni di MLL innanzitutto per studiare il trafficking in vivo e la progressione leucemica delle leucemie acute con traslocazione di MLL. Successivamente sono stati utilizzati i modelli murini per lo studio in vivo dell’efficienza e della tossicità dei siRNA progettati e validati in vitro, valutando diversi sistemi di delivery per i siRNA in vivo.
Chromosomal translocations involving 11q23/MLL gene represent frequent abnormalities in Acute Myeloid Leukemias (AML) subtype FAB M5 and M4, Acute Lymphoblastic Leukemias (ALL) and Biphenotypic Leukemias. MLL-related leukemias are generally associated with aggressive disease and poor prognosis. MLL-related leukemias need validation of new therapies, so we designed and validated anti-MLL siRNA to downregulate MLL-fusion oncogenes. We tested anti-MLL siRNA in MLL-carrying acute leukemias cell lines, and we evaluated both MLL mRNA downregulation, cellular viability and proliferation, and protein inhibition. We also evaluated gene expression of MLL-dependent genes. We generated bioluminescent acute leukemias xenograft mouse models of the most frequent MLL fusion genes. We evaluated leukemias trafficking and progression, and we evaluated delivery methods for siRNA delivery in vivo.
APA, Harvard, Vancouver, ISO, and other styles
2

Lombardini, Lorenza <1982&gt. "Valutazione preclinica di oligonucleotidi antisenso come nuovo approccio terapeutico specifico per le leucemie acute con riarrangiamenti di MLL." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3238/.

Full text
Abstract:
Le Leucemie Acute Mieloidi di sottotipo FAB M4 e M5, le Leucemie Acute Linfoblastiche e le Leucemie Bifenotipiche sono frequentemente caratterizzate da traslocazioni del gene 11q23/MLL con formazione di oncogeni di fusione e produzione di oncoproteine che inducono la trasformazione neoplastica. Tali leucemie con riarrangiamenti di 11q23/MLL sono caratterizzate da prognosi infausta e scarsa responsività alle terapie convenzionali. Data la necessità di trovare terapie efficaci per le leucemie con traslocazione di MLL, in questo lavoro di ricerca sono stati progettati, caratterizzati e validati siRNA per il silenziamento genico degli oncogeni di fusione di MLL, con lo scopo di valutare il ripristino delle normali funzionalità di differenziamento cellulare e l’arresto della proliferazione neoplastica. Sono stati progettati siRNA specifici per gli oncogeni di fusione di MLL, sia per le regioni conservate nei diversi oncogeni di fusione, sia a livello del punto di fusione (breakpoint), sia per le regioni sui geni partner. I siRNA sono stati valutati su linee cellulari contenenti diverse traslocazioni del gene MLL. Il silenziamento è stato valutato sia a livello cellulare in termini di riduzione della capacità proliferativa e del numero delle cellule leucemiche, sia a livello molecolare tramite l’analisi della diminuzione dell’mRNA degli oncogeni di fusione di MLL. E’ stata valutata la diminuzione delle oncoproteine di fusione di MLL in seguito a trattamento con siRNA. E’ stata analizzata la variazione dell’espressione di geni dipendenti da MLL in seguito a trattamento con siRNA. Sono stati messi a punto modelli murini bioluminescenti di leucemie acute con traslocazioni di MLL innanzitutto per studiare il trafficking in vivo e la progressione leucemica delle leucemie acute con traslocazione di MLL. Successivamente sono stati utilizzati i modelli murini per lo studio in vivo dell’efficienza e della tossicità dei siRNA progettati e validati in vitro, valutando diversi sistemi di delivery per i siRNA in vivo.
Chromosomal translocations involving 11q23/MLL gene represent frequent abnormalities in Acute Myeloid Leukemias (AML) subtype FAB M5 and M4, Acute Lymphoblastic Leukemias (ALL) and Biphenotypic Leukemias. MLL-related leukemias are generally associated with aggressive disease and poor prognosis. MLL-related leukemias need validation of new therapies, so we designed and validated anti-MLL siRNA to downregulate MLL-fusion oncogenes. We tested anti-MLL siRNA in MLL-carrying acute leukemias cell lines, and we evaluated both MLL mRNA downregulation, cellular viability and proliferation, and protein inhibition. We also evaluated gene expression of MLL-dependent genes. We generated bioluminescent acute leukemias xenograft mouse models of the most frequent MLL fusion genes. We evaluated leukemias trafficking and progression, and we evaluated delivery methods for siRNA delivery in vivo.
APA, Harvard, Vancouver, ISO, and other styles
3

Albouz, Soulaf. "Evaluation de l’efficacité de l’atovaquone encapsulée associée à des oligonucléotides antisens anti-ARNm de topoisomérase II chez Plasmodium falciparum." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS079.

Full text
Abstract:
Selon les estimations de l'OMS, le bilan mondial du paludisme a atteint 212 millions de cas et 429 000 décèsen 2015 (OMS, 2016). Cette gravité est principalement due à Plasmodium falciparum. A l’heure actuelle, P. falciparum présente des résistances à tous les antipaludiques donnés en monothérapie.Par conséquent, pour réduire le risque d’échec thérapeutique, l'OMS a recommandé depuis 2001 l’utilisation de bithérapie, notamment d'Artemisinin Combination Therapy (ACT), comme traitement de première intention.Les ACT sont composés essentiellement d’un dérivé d’artéminisine, à demi-vie courte et un autre antipaludique à demi-vie longue, connu en monothérapie.Le parasite a également montré des signes de résistance aux ACT, principalement en Asie du Sud-est, menaçant les programmes d’éradications contre le paludisme.La découverte de nouveaux composés à activité antipaludique ou de nouvelles procédures de traitement sont urgentes.La valorisation d’anciennes molécules est également au cœur des études afin d’améliorer notamment leur biodisponibilité et réverser les mécanismes de résistance du parasite. Ainsi, des études prouvent l’intérêt de l’utilisation de nanotechnologies pour l’amélioration de l’efficacité d’antipaludiques. L’atovaquone en est un exemple, cette modification a notamment permis d’améliorer sa biodisponibilité. Notre étude a porté sur une de ces formulations, de l’atovaquone encapsulée dans une nanoémulsion cationique (NE) appelée ATQ. Une deuxième génération a ensuite été testée par association d’oligonucléotides antisens anti-ARNm de topoisomérase II(AST) de P. falciparum. En effet, des stratégies antisens thérapeutiques font leur preuve en santé humaine et présentent un intérêt croissant en parasitologie. Les NE/AST ont montré une activité anti-palustre spécifique contre P. falciparum in vitro. Leur spécificité a permis d’aboutir à l’arrêt du cycle cellulaire et une forte diminution du taux d’ARNm de la topoisomérase II. Ce phénomène a montré être dépendant de l’action de la RNase H. Un effet synergique de ces NE/AST a également été montré en association avec la chloroquine, l’atovaquone et la dihydroartémisinine sur une souche sensible de P. falciparum et des souches résistantes aux antipaludiques précédemment cités.L’ATQ a également montré une forte efficacité sur une souche résistante à l’atovaquone d’un facteur 5. En présence d’ATQ, la mitochondrie a rapidement été altérée conduisant à une mort précoce du parasite. Un traitement à l’ATQ a abouti à la guérison de souris Swiss infectée par P. berghei après deux injections en i.v. en 5 jours. Enfin, l’ATQ/AST a montré une efficacité in vitro contre P. falciparum et P. berghei in vivo. Un test de cytoadhérance des hématies parasitées a des cellules endothéliales a révélé un fort pourvoir d’inhibition de la cytoadhérance de l’ATQ/AST.Un résultat prometteur dans le cadre de traitement du neuropaludisme
According to the estimations of theWHO, in 2015, 212million cases ofmalariahave been reported(WHO,2016). These figuresmakemalariathe most deadlyparasitic diseasein the world, with429.000deaths per year. Some treatments against Plasmodium falciparum exist. However, no really good treatment option can be found in monotherapy due to the resistance emergency. Therefore To reduce the risk of resistance, WHO has recommended since 2001 combination therapies, which is basically an Artemisinin Combined Therapy (ACT), as first-line treatment. The main problem of commercialized bi-therapy is that they are composed of two molecules with individual resistance which leaded to the emergence of resistance to the latest ACTs such as a dihydroartemisinin /piperaquine combinationmainly in South-East Asia.Thus the use of new therapeutic combination strategy that can bypass the parasites' mechanisms of resistance is urgent to effectively treat malaria. As the pathway from drug discovery to drug commercialization is both long and very expensive, it is essential to develop ways to improve existing antimalarial treatments. In the first place it’s necessary to find a new antimalarial formulation based on an already commercialized drug to modify its biodisponibility and its mechanism of action in order to revert the resistance. In the second place its necessary to associate this formulation with a novel none commercialized antimalarial strategy such as the antisens oligonucleotides already usedinhumanhealth. In our lab we have developed nanoemulsions containing atovaquone and antisense oligonucleotides anti topoisomerase II against P. falciparum.Nanoemulsionsvectoringantisens oligonucleotidesandused againstP. falciparum topoisomerase II(NE/AST) showed encouraging anti-parasite killing results.Additionalresultshave showna synergistic in vitro effectwithantimalarial drugs(chloroquine, dihydroartemisinin and atovaquone) in sensitive and resistances strains. Moreover NE/ASTrestricted Topoisomerase II gene expression and blocked the cell cycle in G2/M phase leading to parasite’s death by mitophagy.As Drug delivery systemscan improve the efficacy ofcommon antimalarial drugs by delivering the drug to its target, while protecting it from degradation in biological environment and increasing its biodisponibility, our nanoemulsions containing atovaquone (ATQ) leaded to reversion of atovaquone resistance with 5 fold decrease in its IC50. Observations made with confocal microscopy have shown mitochondrial alteration after ATQ treatment.Our novel and original bi-therapy is focused on the association ofATQ with NE/AST (ATQ/AST).We obtained an IC50 8-fold lower than atovaquone’s IC50with total inhibition of parasites’ capacity to reinfect new red blood cells. A cytoadherence test of parasitized erythrocytes to endothelial cells revealed a strong capacity of cytoadherence inhibition of ATQ / AST, a promising result in the treatment of cerebral malaria
APA, Harvard, Vancouver, ISO, and other styles
4

Yannopoulos, Constantin G. "Synthesis and targeting of antisense oligonucleotides." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0014/NQ37032.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lin, Zhaoru. "Characterisation of antisense oligonucleotide-stimulated ribosomal frameshifting." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609380.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

GODARD, GERARD. "Oligonucleotides antisens modifies : potentialites et limites." Paris 6, 1994. http://www.theses.fr/1994PA066374.

Full text
Abstract:
La stabilite des oligonucleotides antisens vis-a-vis des nucleases, et leur penetration dans les cellules sont deux limitations majeures a leur efficacite. De nombreuses modifications chimiques ont ete realisees pour rendre les oligonucleotides plus stables vis-a-vis des nucleases. Les oligonucleotides font partie de ces molecules chimiquement modifiees. De tels oligonucleotides sont incapables de former des hybrides avec l'arn qui soient substrats de la ribonuclease h, enzyme vraisemblablement implique dans l'activite antisens des oligonucleotides. L'activite d'oligonucleotides ou b couples a des molecules reactives (1,10 phenanthroline ou psoralene) dans le but de pallier a cette deficience, a ete etudiee sur des substrats adn ou arn. La plus faible reactivite de ces molecules observee sur l'arn reflete probablement, au moins en partie, la difference de structure arn/adn et la difference de stabilite des hybrides oligo/arn-oligo/adn. Des oligonucleotides resistants aux nucleases (oligonucleotides contenant des 2,4-dideoxy-b-d-erythro-hexopyranosyls, ou couples a la lithocholamide) ont montre des proprietes interessantes. Il se trouve que certain de ces oligonucleotides peuvent induire une activite de coupure de l'arn par la rnase h plus importante qu'un oligonucleotide non modifie. Un des moyens mis en uvre afin d'ameliorer la penetration des oligonucleotides dans les cellules est de les associer a des transporteurs. L'association d'oligonucleotides a des nanoparticules de polyisohexylcyanoacrylate peut etre realise par l'intermediaire d'un cation hydrophobe, tel que le ctab. Neanmoins, ce cation pose des problemes de toxicite. Nous avons pu associer directement des oligonucleotides couples au cholesterol aux nanoparticules via la molecule de cholesterol et ainsi nous affranchir de la presence du ctab. Ces oligonucleotides, associes au ctab, ont une activite biologique specifique a des concentrations de l'ordre de 200 a 400 nm
APA, Harvard, Vancouver, ISO, and other styles
7

Rouleau, Samuel. "Oligonucléotides comme modulateurs de l'expression génique." Thèse, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/11570.

Full text
Abstract:
L’ARN est sans aucun doute la molécule biologique la plus versatile qui soit. Tout comme l’ADN, il peut contenir et transmettre de l’information génétique. Tout comme les protéines, il peut accomplir une multitude de fonctions biologiques. De plus, son rôle le plus connu demeure celui d’intermédiaire entre l’ADN et les protéines. L’ARN est donc au cœur d’un bon nombre de processus biologiques. Ceci lui confère un immense potentiel thérapeutique qui jusqu’à présent demeure largement inexploité. Pour accomplir ses fonctions, l’ARN doit adopter une structure tridimensionnelle précise qui est dépendante à la fois de sa séquence et de son environnement. Ainsi, en modifiant la structure d’un ARN, il est possible d’en moduler sa fonction. C’est l’objectif global des travaux présentés dans cette thèse. Pour y parvenir, de courts oligonucléotides antisens (OA) ont été utilisés. Cette stratégie revêt plusieurs avantages. Comme les OA s’apparient à leur cible en formant des paires de bases Watson-Crick, ils offrent une grande spécificité et leur design est facile. De plus, en se fiant aux données structurales et aux logiciels de prédictions de structures des ARN, on peut aisément identifier les régions à cibler avec les OA. Enfin, cette technique est versatile puisqu’on peut cibler différents motifs d’ARN. La première cible a été le ribozyme du virus de l’hépatite D. Cet ARN, qui catalyse une réaction d’auto-coupure, a été modifié afin que son activité devienne dépendante à la liaison d’OA. Plusieurs modules ont ainsi été créés et combinés afin d’obtenir des ribozymes qui répondaient à la présence d’un ou plusieurs OA. En insérant ces interrupteurs moléculaires dans les régions non traduites d’un ARNm, nous avons ainsi modulé l’expression de ce gène avec les OA. Cet outil a des applications intéressantes pour la régulation de gènes en biologie synthétique. Un autre motif ciblé a été le G-quadruplex (G4). Cette structure non canonique exerce de nombreuses fonctions biologiques et représente donc une cible thérapeutique intéressante. Lorsque présent dans la région 5’ non traduite d’un ARNm, le G4 mène généralement à une diminution de la traduction. En utilisant des OA qui empêchent la formation du G4, nous avons été en mesure d’augmenter la traduction du gène ciblé. De plus, il a été possible de développer des OA qui favorisent la formation d’un G4 dans le but de diminuer l’expression de la cible. Finalement, dans le dernier chapitre de cette thèse, il est démontré que les G4 présents dans les microARN primaires influencent leur maturation en microARN matures. Des OA ciblant ces G4 ont été utilisés afin de favoriser la maturation de microARN suppresseurs de tumeurs, ce qui présente un potentiel thérapeutique intéressant. En bref, les travaux présentés dans cette thèse démontrent clairement que les OA sont un outil de choix pour cibler et modifier la structure de motifs d’ARN spécifiques.
Abstract : RNA is a versatile biological molecule. Like DNA, it can contain and transmit genetic information. Like proteins, it can accomplish multiple biological functions. Also, its most known role remains that of intermediary between DNA and proteins. RNA is thus a key player in many biological processes. This gives it an immense therapeutic potential which remains largely untapped. To fulfill its functions, RNA must adopt a precise threedimensional structure that is dependent on both its sequence and its environment. Thus, by modifying the structure of an RNA, it is possible to modulate its function. This is the overall objective of the work presented in this thesis. To achieve this, small antisense oligonucleotides (ASO) have been used. This strategy has several advantages. As ASO bind their target with Watson-Crick base pairs, they offer great specificity and their design is easy. Moreover, reliance on structural data and RNA structure prediction softwares makes it easy to identify the regions to be targeted with ASO. Finally, this technique is versatile since it is possible to target different RNA motifs. The first target was the HDV self-cleaving motif. This RNA, which catalyzes a self-cleaving reaction, has been modified so that its activity became dependent on the binding of ASO. Several modules were thus created and combined in order to obtain ribozymes which responded to the presence of one or more ASO. By inserting these molecular switches into an mRNA’s UTR, the expression of this gene was modulated with the ASO. This has interesting applications for the regulation of genes in synthetic biology. Another target motif was the G-quadruplex (G4). This non-canonical structure exerts many biological functions and therefore represents an interesting therapeutic target. When present in the mRNA’s 5’UTR, G4 generally lead to a decrease in translation. Using ASO that prevent G4 formation, we were able to increase the translation of the target gene. In addition, it has been possible to develop ASO which promote the formation of a G4 in order to decrease the expression of the target. Finally, in the last chapter of this thesis, it is demonstrated that the G4 present in the primary microRNAs influence their maturation in mature microRNAs. ASO targeting these G4 have been used in order to promote the maturation of tumor suppressor microRNAs, which has an interesting therapeutic potential. The work presented in this thesis clearly demonstrates that ASO are ideal for targeting and altering the structure of specific RNA motifs.
APA, Harvard, Vancouver, ISO, and other styles
8

Chalk, Alistair. "Computational prediction of antisense oligonucleotides and siRNAs /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-376-0/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Gill, Taylor Elizabeth. "Selective targeting of MYC by antisense oligonucleotides." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115602.

Full text
Abstract:
Thesis: Ph. D. in Biomedical Engineering, Harvard-MIT Program in Health Sciences and Technology, 2018.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 181-208).
MYC is one of the most commonly dysregulated genes across all cancers. As a master transcription factor with greater than 10,000 binding sites throughout the genome, the MYC oncoprotein coordinates a transcriptional regulatory network consisting of approximately 15% of all genes, controlling cancer hallmark expression programs responsible for cellular proliferation, growth, metabolism, and evasion from apoptosis. MYC dysregulation occurs genetically, epigenetically, and post-transcriptionally through a wide variety of mechanisms. Despite its well-characterized properties as a proto-oncogene, direct potent and selective inhibition of MYC remains a significant challenge. Models of systemic MYC inhibition utilizing inducible genetic constructs in mice have revealed that inhibition of MYC activity leads to potent tumor regression with an evident therapeutic window, suggesting that pharmacologic MYC inhibition may be a viable cancer therapeutic strategy. Small molecule inhibitors designed to block MYC protein activity exhibit low potency, display poor selectivity, and lack antitumor efficacy, which has led MYC to be historically classified as 'undruggable.' Efforts aimed at indirectly targeting MYC transcription often lead to development of resistance characterized by reinforced expression of MYC. Clearly, alternate strategies are needed to achieve selective and potent inhibition of MYC. The goals of this research were to develop antisense oligonucleotides specifically targeted against the MYC mRNA to achieve potent inhibition of MYC translation, and to characterize the activity of these molecules as specific modulators of MYC expression and as prototypical MYC-directed therapeutics. We designed and synthesized a library of MYC-targeting antisense oligonucleotides (MYCASOs) containing several chemical synthetic features to increase target affinity and stability. Treatment of MYC-expressing cancer cells with MYCASOs leads to RNase H-mediated cleavage of MYC mRNA and a potent decrease in MYC protein levels. MYC knockdown is accompanied by significant effects on cellular viability and inhibition of cellular proliferation. Furthermore, MYCASO treatment specifically perturbs MYC-driven gene expression signatures. In a MYC-induced murine model of hepatocellular carcinoma, MYCASO treatment leads to cleavage of the MYC transcript, decreased MYC protein levels within tumors, and reduced tumor burden. MYCASOs represent a new chemical tool for in vitro and in vivo modulation of MYC activity, and promising therapeutic agents for MYC-addicted tumors.
by Taylor Elizabeth Gill.
Ph. D. in Biomedical Engineering
APA, Harvard, Vancouver, ISO, and other styles
10

Åström, Hans. "Studies on phosphate ester cleavage and development of oligonucleotide based artificial nucleases (OBAN's) /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-935-8/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Patel, Ramila. "Delivery and stability of antisense oligonucleotide conjugates in vitro." Thesis, Aston University, 1998. http://publications.aston.ac.uk/10983/.

Full text
Abstract:
The aim of this project was to study the delivery of ODNs to macrophages and to assess the stability of two ODN conjugates, in vitro. The first conjugate aimed to improve uptake of ODNs via mannose receptor mediated delivery, the second investigated the improved delivery of ODN conjugates via non-specific lipophilic interaction with the cell membrane. A mono-mannose phosphoramidite derivative was designed and synthesised and a mono-mannose ODN conjugate synthesised by standard phosphoramidite chemistry. Delivery of this conjugate was enhanced to RAW264.7 and J774 macrophage cell lines via a mechanism of receptor mediated endocytosis. The delivery of three lipophilic ODN conjugates, cholesterol (cholhex), 16-carbon alkyl chain (C16) and hexa-ethylene glycol (HEG) moieties and an unconjugated ODN were assessed in RAW264.7 macrophages. All three conjugates increased the lipophilicity of the ODN as assessed from partition coefficient data. Both the cholhex and unconjugated ODNs were found to have higher degrees of cellular association than the C16 and HEG conjugates. Cellular uptake studies implicated internalisation of these ODNs by an adsorptive endocytosis mechanism. Following endocytosis, ODNs must remain stable during their residence in endosomal/lysosomal compartments prior to exiting and exerting their biological action in either the cytosol or nucleus. Assessment of in vitro stability in a lysosomal extract revealed the cholhex conjugate and unconjugated ODNs to have a longer half-life than the C16 and HEG conjugated ODNs, highlighting the influence of conjugate moieties on lysosomal stability. The effects of base composition and length on stability in a lysosomal extract revealed the longest half-life for homo-cytidine ODNs and ODNs over 20 nucleotides in length. These studies suggest that the above conjugates can enhance cellular association and delivery of antisense ODNs to cultured macrophages. This may lead to their use in treating disorders such as HIV infection, which affects this cell type.
APA, Harvard, Vancouver, ISO, and other styles
12

Zaramella, Simone. "Development of a novel methodology for the synthesis of oligonucleotide-peptide conjugates /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-919-6/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Barnes, Colin Lloyd. "Studies in the synthesis of novel antisense oligo nucleotides." Thesis, Institute of Cancer Research (University Of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264958.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

BERTON, MYRIAM. "Application des biovecteurs supramoleculaires (bvsm) a la strategie antisens : incorporation et protection d'oligonucleotides, etude de leur devenir cellulaire et effet antisens." Paris 11, 1996. http://www.theses.fr/1996PA114823.

Full text
APA, Harvard, Vancouver, ISO, and other styles
15

Schmidt, Kathrin Susanne. "Solution- and solid-phase synthesis of monofunctionally trans-Pt(II) modified oligonucleotides and oligonucleotide analogues and their potential application in antigene and antisense strategy." Berlin : Logos-Verl, 2001. http://www.gbv.de/dms/bs/toc/331517116.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

McIntosh, Craig Stewart. "Antisense oligonucleotide-mediated therapeutic strategies for neurodegenerative repeat expansion diseases." Thesis, McIntosh, Craig Stewart (2020) Antisense oligonucleotide-mediated therapeutic strategies for neurodegenerative repeat expansion diseases. PhD thesis, Murdoch University, 2020. https://researchrepository.murdoch.edu.au/id/eprint/57526/.

Full text
Abstract:
Over 40 diseases, primarily affecting the nervous system, are caused by expansion of simple repetitive sequences found throughout the human genome, termed repeat expansion diseases. Expansions can occur in coding and non-coding regions of the genome, leading to several proposed mechanisms of disease, accumulation of either toxic RNA or toxic protein, although gain-of-function mechanisms are suggested causes of pathogenesis. Currently, there is no cure nor effective treatment strategy for any repeat expansion diseases. However, for many of these expansion diseases, splice-switching antisense oligonucleotides (AOs) may offer promise as a therapeutic strategy, as these compounds have already demonstrated efficacy in the treatment of other types of genetic disorders. Antisense oligonucleotides are short synthetic nucleic acid analogues, designed to target specific pre-mRNA sequences by reverse-complementary Watson-Crick binding, thereby modifying processing and/or abundance of the transcript and the sequence of the encoded protein. While there are a number of applications for AOs, this study focuses on their utility for preventing translation of toxic protein isoforms, either by altering the target transcript to encode a truncated protein isoform, or by disrupting the reading frame to downregulate endogenous protein production. The first part of this study focused on ameliorating the toxic polyglutamine tract found in the ataxin-3 protein that causes spinocerebellar ataxia type 3 (SCA3). One of nine known polyglutamine disorders, SCA3 is a clinically heterogeneous disease, primarily exemplified by progressive ataxia impairing the speech, balance and gait of affected individuals. SCA3 is caused by expansion of a glutamine-encoding tract located at the 5′ end of the penultimate exon (exon 10) of the ATXN3 gene transcript, resulting in conformational changes in ataxin-3 and a toxic gain-of-function. Here, we describe highly efficient removal of the toxic polyglutamine tract of ataxin-3 in vitro by phosphorodiamidate morpholino oligomers (PMOs). Additionally, these PMOs induced a potentially beneficial downregulation of both the expanded iv and non-expanded protein isoforms. As SCA3 has a typical age of onset in the fourth decade, the observed downregulation could delay age of onset by reducing the amounts of the toxic aggregates. Although we induce downregulation of both isoforms, we believe that the proportion of the truncated protein may be sufficient for overall function of ataxin-3, as some studies have shown ataxin-3 protein to be partially dispensable. Recently, several in vitro and in vivo studies have found that targeted knockdown of transcription elongation factors SUPT4H1, and to a lesser extent SUPT5H, can reduce aggregation of expanded transcripts and protein, and alleviate the disease phenotype in animal models of various expansion diseases. We therefore sought to investigate in vitro, the potential of AO-mediated SUPT4H1 downregulation as a therapeutic strategy. We found that our AOs were able to significantly downregulate SUPT4H1, with minimal changes to the rest of the transcriptome. We then assessed whether this downregulation of SUPT4H1 lead to a reduction in expanded ATXN3 mRNA and/or ATXN3 protein expression, however, unfortunately in the models available and under the current study, no modification to the ATXN3 transcript or protein was observed. This lack of effect may be due to the relatively short, expanded repeat lengths in SCA3 cell lines, and we therefore recommend that future studies assess genes with larger expansions, such as the 100-1000s repeat tracts frequently observed in myotonic dystrophy type 1 (DMPK). In order to create an efficient screening process for finding clinic-ready AOs, it is important to have a detailed understanding of the principles of AO design. We therefore present a comprehensive rationale for efficiently design and in vitro delivery of splice modulating AOs. These approaches and recommendations provide a streamlined methodology for any researcher developing AO therapeutics. The results presented in this thesis indicate that morpholino oligomers will provide superior benefit for the treatment of spinocerebellar ataxia type 3, without the toxic effects that result from other antisense oligomer chemistries. Additionally, AO-induced SUPT4H1 knockdown may yet demonstrate therapeutic v application for a multitude of expansion diseases, pending further investigation into the whole transcriptome effects and in vivo efficacy of this strategy. Lastly, our guidelines for therapeutic AO development should aid other researchers in creating the most efficacious and safe AOs for clinical trials. The work presented in this thesis contributes to the greater body of knowledge about the applications of AOs, as well as the need for reliable and systematic protocols in AO research and interpretation. With ongoing collaboration from our industry partners, Sarepta Therapeutics, there is hope that the work presented here will provide a solid foundation for further research into AO therapeutics for the treatment of neurodegenerative expansion diseases.
APA, Harvard, Vancouver, ISO, and other styles
17

Greco, Valentina. "Synthesis and bio-pharmacological activity of antisense phosphatidyl-oligonucleotides." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/962.

Full text
Abstract:
Lipid conjugated oligonucleotides are of great interest in the field of antisense oligonucleotides used for functional genomics, gene target validation and therapeutic pourpose. Although various lipid conjugates of oligonucleotides have already been prepared, it was not possible until now to prepare phosphatidyl conjugates owing to an actual difficulty encountered in a direct attachment of the phosphatidyl group to oligonucleotides elongated on the solid phase by standard phosphoramidite chemistry procedures. Now, appropriately exploiting some synthetic opportunities, available in the recent literature for the preparation of oligonucleotides bearing residual base-labile side groups, we designed a synthetic path to obtain 5 -O-phosphatidyloligonucleotides. By applying this synthetic route we prepared some phosphatidyltetradecanucleotides all having the antisense sequence against the Vascular Endothelial Growth Factor (VEGF) gene, but differing from each other in their phosphatidyl moiety. This consisting of different fatty acyl residues, such as myristoyl, palmitoyl and stearoyl as well. The newly synthesized phosphatidyloligonucleotides have been analyzed for their spectroscopic (NMR, MS) and chromatographic (HPLC) properties which confirmed the expected structure. The annealing features of these compounds have been investigated by Differential Scanning Calorimetry analysis . As a preliminary experiment, the antisense effectiveness of 1,2-O-dimyristoyl- and 1,2-O-dipalmitoyl-sn-glycero-3-O-phosphoryl-tetradeca-mers has been assessed by observing their effect on the expression of VEGF at mRNA level in human Neuroblastoma cells. Both the phosphatidyl-tetradecamers were able to inhibit the expression of VEGF mRNA with an effective concentration significantly lower than was found, in parallel experiments, for the corresponding unmodified antisense oligonucleotide.
APA, Harvard, Vancouver, ISO, and other styles
18

Guterstam, Peter. "Specificity of antisense oligonucleotide derivatives and cellular delivery by cell-penetrating peptides." Doctoral thesis, Stockholm : Department of Neurochemistry, Stockholm University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-31226.

Full text
Abstract:
Diss. (sammanfattning) Stockholm : Stockholms universitet, 2009.
At the time of doctoral defense, the following papers were unpublished and had s status as follows: Paper 4: Accepted.Peper 5: In press. Härtill 5 uppsatser.
APA, Harvard, Vancouver, ISO, and other styles
19

Imbert, Marine. "Evaluation de différentes stratégies thérapeutiques antisens pour le traitement de la maladie de Huntington." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV044/document.

Full text
Abstract:
La maladie de Huntington (MH) est causée par une expansion de répétitions CAG sur l’exon 1 du gène huntingtine (htt), codant pour une protéine mutée. Il a été montré que la diminution d’expression de cette protéine est une piste thérapeutique très prometteuse. Dans ce projet, nous avons étudié et comparé trois approches dites «antisens» : une stratégie allèle non-spécifique, visant à diminuer de manière générale l’expression de htt ; une stratégie allèle spécifique ciblant les répétitions CAG afin d’impacter préférentiellement l’allèle muté ; et enfin une stratégie de saut d’exon permettant d’enlever des sites de clivage à l’origine d’une forme raccourcie et toxique de la protéine htt. Nous avons évalué ces approches grâce à deux outils différents : les tricyclo-DNA (TcDNA), qui sont une nouvelle classe d’oligonucléotides antisens (AON) plus performante que les chimies précédentes, et le système U7snRNA vectorisé, permettant d’induire une expression stable des séquences antisens. Dans un premier temps, ces différentes molécules ont été évaluées in vitro dans des lignées de fibroblastes de patients en quantifiant le niveau d’ARNm et de protéines htt par RTqPCR et Western blot respectivement. Par la suite, les séquences les plus efficaces in vitro ont été sélectionnées et les AON et AAV-U7snRNA correspondants ont été injectés en intracérébroventriculaire (ICV) dans un modèle murin de la MH (souris YAC128). Les résultats les plus encourageants ont été obtenus avec le TcDNA-NS (pour allèle Non Spécifique), permettant une diminution significative de l’expression de htt dans le cortex, l’hippocampe et le striatum 2 et 6 semaines après une injection ICV. Ces résultats prometteurs suggèrent le potentiel des TcDNA comme nouvel outil thérapeutique pour la MH
Huntington’s disease (HD) is caused by a CAG repeat expansion in the exon 1 of huntingtin gene (htt), encoding for a mutant protein. It has been shown that the silencing/down regulation of huntingtin protein is a promising therapeutic lead. In this project, I have explored and compared three strategies using the antisense approach: a non-allele specific strategy, aiming to silence the global expression of htt; an allele specific strategy targeting CAG repeats to silence preferentially the mutant allele; and an exon-skipping strategy in order to remove cleavage sites which originally cause a shorter and toxic form of the htt protein. These strategies have been evaluated using two different tools: tricyclo-DNA (TcDNA), a new class of antisense oligonucleotides (AON) more efficient than the previous chemistries, and a vectorized approach using U7snRNA system allowing a stable expression of antisense sequences. Firstly, these different molecules have been assessed in vitro in HD fibroblasts quantifying mRNA and htt protein levels with RTqPCR and Western blot respectively. Subsequently, the most efficient sequences have been selected and intracerebroventricular (ICV) injections have been performed with corresponding AON and AAV-U7snRNA in a HD mouse model (YAC128). The most encouraging results have been obtained with the TcDNA-NS (for Non Specific allele), allowing a significant decrease of htt expression in cortex, hippocampus and striatum 2 and 6 weeks after ICV injection. These promising results suggest the potential of TcDNA as a new therapeutic tool for HD
APA, Harvard, Vancouver, ISO, and other styles
20

Fürst, Christiane. "Charakterisierung biopolymerer Trägersysteme für Antisense-Oligonukleotide mittels fluorescence correlation spectroscopy /." Aachen : Shaker, 2008. http://d-nb.info/98842519X/04.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

Aynie, Isabelle. "Vectorisation d'oligonucleotides antisens par des nanoparticules d'alginate (doctorat : pharmacotechnie et biopharmacie)." Paris 11, 1999. http://www.theses.fr/1999PA114804.

Full text
APA, Harvard, Vancouver, ISO, and other styles
22

Knights, Sally Ann. "The study and synthesis of 2'-C-functionalised nucleosides." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343966.

Full text
APA, Harvard, Vancouver, ISO, and other styles
23

Robinson, Emma S. J. "The pharmacology of an antisense oligonucleotide to the α2A/D-adrenoceptor." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297847.

Full text
APA, Harvard, Vancouver, ISO, and other styles
24

Islam, Aminul. "Down-regulation of central glucocorticoid receptor expression using antisense oligonucleotide technology." Thesis, Aston University, 2000. http://publications.aston.ac.uk/12358/.

Full text
Abstract:
Endogenous glucocorticoids and serotonin have been implicated in the pathophysiology of depression, anxiety and schizophrenia. This thesis investigates the potential of downregulating expression of central Type II glucocorticoid receptors (GR) both in vitro and in vivo, with empirically-designed antisense oligodeoxynucleotides (ODN), to characterise GR modulation of 5-HT2A receptor expression using quantitative RT-PCR, Western blot analysis and radioligand binding. The functional consequence of GR downregulation is also determined by measuring 1-(2,5-dimethoxy 4-iodophenyl)-2-amino propane hydrochloride (DOI) mediated 5-HT2A receptor specific headshakes. Using a library of random antisense ODN probes, RNAse H accessibility mapping of T7-primed, in vitro transcribed GR mRNA revealed several potential cleavage sites and identified an optimally effect GR antisense ODN sequence of 21-mer length (GRAS5). In vitro efficacy studies using rat C6 glioma cells showed a 56% downregulation in GR mRNA levels and 80% downregulation in GR protein levels. In the same cells a 29% upregulation in 5-HT2A mRNA levels and 32% upregulation in 5-HT2A protein levels was revealed. This confirmed the optimal nature of the GRAS5 sequence to produce marked inhibition of GR gene expression, and also revealed GR modulation of the 50-HT2A receptor subtype in C6 glioma cells to be a tonic repression of receptor expression. The distribution of a fluorescently-labelled GRAS5 ODN was detected in diverse areas of the rat brain after single ICV administration, although this fluorescence signal was not sustained over a period of 5 days. However, fluorescently-labelled GRAS5 ODN, when formulated in polymer microspheres, showed diverse distribution in the brain which was maintained for 5 days following a single ICV administration. This produced no apparent neurotoxic effects on rat behaviour and hypothalamic-pituitary-adrenal (HPA) axis homeostasis.
APA, Harvard, Vancouver, ISO, and other styles
25

Duggan, Brian J. "The role of antisense Bcl-2 oligonucleotides in bladder cancer." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326412.

Full text
APA, Harvard, Vancouver, ISO, and other styles
26

Giusiano-Courcambeck, Sophie. "Rôle de TP53INP1 dans l'histoire naturelle du cancer prostatique." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM5007/document.

Full text
Abstract:
Le cancer de la prostate (CaP) est actuellement le cancer le plus fréquent en France et constitue l'une des principales causes de décès par cancer chez l'homme dans les pays industrialisés. Un tiers des patients avec un CaP à priori localisé auront déjà des micro-métastases au moment du traitement local. Ces patients qui répondent dans un premier temps à la castration (hormonothérapie) seront cependant en échappement hormonal dans les 2 ans qui suivent. Récemment, plusieurs essais cliniques de phase III ont rapporté un gain de survie avec la chimiothérapie à base de docétaxel dans les CaPs métastatiques résistants à la castration. Néanmoins, la survie n'est prolongée que de 2 ou 3 mois et de nouvelles approches thérapeutiques ciblant des voies de signalisation spécifiques sont donc nécessaires. Les travaux réalisés au cours de cette Thèse ont permis tout d'abord de montrer, grâce à l'utilisation de TMAs, que la surexpression de TP53INP1, une protéine de réponse au stress, était un facteur de mauvais pronostic dans le CaP, prédictif notamment du risque de rechute biologique. Nous avons ensuite pu montrer grâce à des xénogreffes de cellules tumorales (LNCaP) que les taux d'ARNm de TP53INP1 diminuaient durant l'hormonothérapie et que TP53INP1 était de nouveau significativement surexprimée dans les tumeurs résistantes à la castration. Nous avons développé et déposé un brevet pour un oligonucléotide antisens (ASO) inhibant TP53INP1. Le traitement in vitro des lignées cellulaires hormonosensibles LNcaP et hormono-résistantes C4-2 par l'ASO induit une diminution d'expression de la protéine TP53INP1, inhibe la prolifération cellulaire et induit une augmentation de l'apoptose
Prostate cancer (PC) is the most common malignancy in France and one of the most frequent leading causes of cancer-related death in men in industrialized countries. Even with aggressive screening, approximately one-third of patients believed to have localized PC will already have micro-metastatic disease at the time of definitive local therapy. These patients initially respond to androgen ablative therapy, but with time, their tumors ultimately become unresponsive and recur within 2 years as castration-resistant prostate cancer (CRPC). Recently, docetaxel-based regimens have shown improved survival in men with CRPC in phase III studies. However, the median overall survival was prolonged for only 2-3 months, and thus development of new therapeutic approaches that target relevant signaling pathways are essential to restore the androgen-sensitivity of CRPC. We showed, using tissue micro-array (TMA) analysis, that over-expression of Tumor Protein 53-Induced Nuclear Protein 1 (TP53INP1), a cell stress response protein, is a worse prognostic factor in PC, particularly predictive of biological cancer relapse. We also we found that TP53INP1 protein expression decreases during castration therapy (CT) and significantly increases in human CRPC. TP53INP1 mRNA was also significantly increased in castration-resistant (CR) tumors of LNCaP xenograft compared to the castration-sensitive (CS) taken before CT. We developed and world-wide patented one antisense oligonucleotide (ASO) targeting TP53INP1 (PCT/IB2011/054555). Treatment of LNCaP and C4-2 cells in vitro with TP53INP1 ASO downregulates TP53INP1 protein level, inhibits proliferation and induces apoptosis
APA, Harvard, Vancouver, ISO, and other styles
27

Aupy, Philippine. "Le développement préclinique des tcDNA pour la Dystrophie Musculaire de Duchenne Evaluating the impact of variable phosphorothioate content in tricyclo-DNA antisense oligonucleotides in a Duchenne Muscular Dystrophy mouse model Identifying and avoiding tcDNA-ASO sequence specific toxicity for the development of DMD exon 51 skipping therapy Long term efficacy of AAV9-U7snRNA mediated exon 51 skipping in mdx52 mice The use of tricyclo-DNA for the treatment of Genetic Disorders Exon-skipping advances for Duchenne Muscular Dystrophy." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLV083.

Full text
Abstract:
La Dystrophie Musculaire de Duchenne est une maladie génétique mortelle qui touche un garçon sur 3500. Elle se manifeste par une faiblesse musculaire progressive conduisant à une perte de la marche autour de l’âge de 10 ans, puis des problèmes respiratoires et cardiaques. Elle est due à des mutations dans le gène DMD conduisant à une absence de la protéine dystrophine. Il n’existe à l’heure actuelle aucun traitement satisfaisant. L’une des stratégies thérapeutiques les plus prometteuses pour cette maladie consiste à moduler l’épissage de l’ARN pré-messager. Cette stratégie appelée aussi « saut d’exon » utilise principalement des oligonucléotides antisens qui vont permettre de restaurer le cadre de lecture et ainsi entrainer la production de protéine.Le laboratoire Biothérapie des Maladies du Système Neuromusculaire a développé une nouvelle chimie d’oligonucléotide antisens, les tricyclo-DNA (tcDNA), ayant fait leur preuve pour effectuer un saut de l’exon 23 efficace dans des modèles murins de la DMD. En effet, les chercheurs de l’équipe ont pu démontrer la présence de saut d’exon et de restauration de dystrophine dans l’ensemble de la musculature et dans le système nerveux central, permettant d’obtenir une amélioration fonctionnelle. Lors de ma thèse, je me suis intéressée au développement pré-clinique d’un tcDNA ciblant l’exon 51 humain, puisqu’il s’agit de l’exon permettant de traiter la plus grande proportion de patients (13%).La première partie de mon projet a été consacrée à l’amélioration de la tolérabilité des tcDNAs à travers deux approches : la modification de la séquence et la modification du design de la molécule. En effet, la cause principale de la toxicité des tcDNAs est la formation de structures homodimériques associée à la présence de liens phosphorothioates (PS). Cette première étude a permis, d’une part, de démontrer qu’une modification de la séquence entraine une élimination des structures homodimériques et permet ainsi d’obtenir une meilleure tolérabilité de la molécule. D’autre part nous avons pu mettre en évidence qu’une diminution du contenu en liens PS permet de limiter l’apparition d’une toxicité à long terme sans impacter significativement l’efficacité.La deuxième partie de mon projet de thèse a été consacrée à l’optimisation de l’efficacité des tcDNAs. Pour cela deux approches ont été investiguées : d’une part l’amélioration de la biodisponibilité de la molécule et d’autre part l’optimisation de la séquence cible. Nous avons ainsi pu démontrer que la conjugaison d’un acide gras à un tcDNA entraine une amélioriation significative de sa biodistribution et de l’efficacité du tcDNA. En parallèle, un criblage de nombreuses séquences ciblant différentes régions de l’exon 51 a permis de sélectionner une séquence candidate présentant une efficacité nettement supérieure à celle de la séquence initiale. Cette séquence, conjuguée à un acide palmitique, a démontrée des résultats extremement encourageants pour les futurs essais cliniques et est actuellement en phase finale de développement préclinique
Duchenne Muscular Dystrophy is a fatal genetic disorder affecting 1/3500 newborn males. It is characterized by progressive muscle weakness causing loss of ambulatory functions and respiratory and cardiac failures. This disease is due to mutations in the DMD gene leading to complete loss of protein expression. There is currently no satisfactory treatment but one of the most promising therapeutic strategy is splicing modulation. This strategy also called “exon skipping” is achieved through the use of antisense oligonucleotides allowing a restoration of the reading frame, and thus leading to protein rescue.The laboratory Biothérapie des Maladies du Système Neuromusculaire has developped a new chemistry of antisense oligonucleotide, tricyclo-DNA (tcDNA). They have demonstrated the therapeutic potential of tcDNA in different mouse models of DMD. Indeed, after systemic treatment significant exon 23 skipping and dystrophin restoration were found in all tested muscles as well as in the central nervous system, leading to functional improvement. During my phD project, I worked on the pre-clinical development of a tcDNA targeting human exon 51, which could be applicable to a large proportion of DMD patients (13%).The first part of my project was dedicated to the improvement of tcDNA tolerability through the modification of the sequence itself and the modification of the chemical design. Indeed, the major cause of tcDNA toxicity is the formation of homodimeric structure associated with the presence of phosphorothioates linkages (PS). In this study, we were able to demonstrate that modification of the toxic sequence impairs homodimerization, thus suppressing toxicity. Moreover, we have demonstrated that a decrease in the PS content prevent the apparition of long term toxicity without impairing significatively exon skipping efficacy but.The second part of my project focused on the optimisation of tcDNA efficacy through improvement of their biodisponibility and optimisation of the targeted sequence. We first demonstrated that fatty acid conjugation to tcDNA significantly improves biodistribution and efficacy. In parallel, we screened numerous sequences targeting different regions of the exon 51 and selected a novel sequence with a significantly higher efficacy than the initial sequence. This novel tcDNA sequence, once conjugated with palmitic acid demonstrated extremely encouraging results for the treatment of DMD and we are currently finalizing its development for future clinical trials
APA, Harvard, Vancouver, ISO, and other styles
28

Webb, Andrew Russell. "The development of BLC-2 antisense oligonucleotide therapy for non-Hodgkin's lymphoma." Thesis, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405100.

Full text
APA, Harvard, Vancouver, ISO, and other styles
29

Ruddell, Carolyn Jennifer. "Antisense oligonucleotide-mediated inhibition of mutant P53 expression in cultured human cells." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367250.

Full text
APA, Harvard, Vancouver, ISO, and other styles
30

Walton, S. Patrick (Stephen Patrick) 1973. "Thermodynamics and kinetics of antisense oligonucleotide hybridization to a structured mRNA target." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/43615.

Full text
Abstract:
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, February 2002.
Includes bibliographical references (p. 165-178).
Antisense oligonucleotides have the potential to selectively inhibit the expression of any gene with a known sequence. Antisense-based therapies are under development for the treatment of infectious diseases as well as complex genetic disorders. Although there have been some remarkable successes, realizing this potential is proving difficult because of problems with oligonucleotide stability, specificity, affinity, and delivery. Each of these limitations has been addressed experimentally through the use of chemically-modified oligonucleotides and oligonucleotide conjugates, with much success in enhancing oligonucleotide efficacy. These early studies have shown that selection of target site, once considered a trivial problem, is critical to the success of antisense strategies. It has become clear that the efficacy of antisense oligonucleotides is a strong function of the structure of the target mRNA. Though single-stranded, RNA molecules are typically folded into complex three-dimensional structures, formed primarily by intramolecular Watson-Crick base-pairing. If an oligonucleotide is complementary to a sequence embedded in the three dimensional structure, the oligonucleotide may not be able to bind to its target site and exert its therapeutic effect. Because the majority of the structure of RNA molecules is due to Watson-Crick base-pairing, relatively accurate predictions of these folding interactions can be made from algorithms that locate the structure with the most favorable free energy of folding.
(cont.) Taking advantage of the predictability of RNA structures, this thesis addresses the problem of antisense target site selection, first from a theoretical and subsequently an experimental standpoint. A thermodynamic model to predict the binding affinity of oligonucleotides for their target mRNA is described and validated using multiple in vitro and cell-culture based experimental data sets. Subsequently, direct experimental comparisons with theoretical predictions are made on the well-characterized rabbit-[beta]-globin (RBG) mRNA, using a novel, centrifugal, binding affinity assay. The importance of the hybridization kinetics is also explored, as is the role of association kinetics in defining the rate of cleavage by the enzyme ribonuclease H (RNase H). Finally, the applicability of the model in identifying biologically active oligonucleotides is demonstrated.
by S. Patrick Walton.
Sc.D.
APA, Harvard, Vancouver, ISO, and other styles
31

Dai, Guowei. "Pharmacokinetics,pharmacodynamics and metabolism of BCL-2 antisense phosphorothioate oligonucleotide G3139 (Genasense)." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1110309701.

Full text
Abstract:
Thesis (Ph. D.)--Ohio State University, 2005.
Document formatted into pages; contains 375 p. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2006 March 9.
APA, Harvard, Vancouver, ISO, and other styles
32

Li, Dunhui. "Antisense oligonucleotide-mediated exon skipping strategies as the treatment for rare diseases." Thesis, Li, Dunhui (2020) Antisense oligonucleotide-mediated exon skipping strategies as the treatment for rare diseases. PhD thesis, Murdoch University, 2020. https://researchrepository.murdoch.edu.au/id/eprint/58829/.

Full text
Abstract:
Antisense oligomer-mediated exon skipping is being developed as a strategy for personalised treatment of genetic disorders through excising “in-frame” exons carrying small mutations or restoring the reading frame around frame-shifting deletions. The rationale behind this strategy for Duchenne muscular dystrophy is the correlation between dystrophin genotype and clinical phenotype. Null dystrophin mutations (frame-shifting deletions/duplications, nonsense mutations, splice site defects) typically lead to the severe Duchenne muscular dystrophy, whereas deletion of an in-frame exon, or exon blocks, generally leads to the milder Becker muscular dystrophy. The loss of in-frame exon(s) that results in Becker muscular dystrophy indicates non-essential dystrophin coding domains, providing templates for potentially functional dystrophin isoforms. The FDA accelerated approval of Eteplirsen, Golodirsen and Viltolarsen, and the approval of a new drug application seeking accelerated approval for an additional antisense oligomer to address common DMD mutations, have highlighted the therapeutic potential of exon skipping compounds. However, there is lack of genotype-phenotype correlation downstream of DMD exon 55, as deletions in this region are rare and the exonic arrangement is such that most deletions would disrupt the reading frame. Superficial similarities between DMD and PRKN include the very large gene size, very small exon content and the observation that both are deletion prone, and it appears that a similar “redundancy” of particular exons exists in the parkin gene. Parkinson’s patients with the in-frame deletion of PRKN exons 3 and 4 show later onset and milder disease course than patients with only single exon 3 or 4 frame-shifting deletions. This suggests that appropriate PRKN skipping to restore the reading frame and some function of parkin could be developed as a novel therapy for autosomal recessive juvenile-onset Parkinson’s patients. This thesis describes the induction of “Becker muscular dystrophy-like” in-frame dystrophin isoforms by skipping in-frame exon blocks downstream of DMD exon 55 in mice. A similar strategy of exon skipping was used to restore the PRKN reading frame in patient cells carrying a PRKN exon 3 deletion by skipping exon 4. Functional tests confirmed the activities of the induced protein isoforms. In this manner, we hope to expand the application of exon skipping strategies as the treatment of inherited rare diseases, including Duchenne muscular dystrophy and Parkin-type autosomal recessive juvenile-onset Parkinson’s disease.
APA, Harvard, Vancouver, ISO, and other styles
33

Cale, Jessica M. "Antisense oligonucleotide-mediated alternative splicing strategies to treat the type-1 fibrillinopathies." Thesis, Cale, Jessica M. (2021) Antisense oligonucleotide-mediated alternative splicing strategies to treat the type-1 fibrillinopathies. PhD thesis, Murdoch University, 2021. https://researchrepository.murdoch.edu.au/id/eprint/61321/.

Full text
Abstract:
The type-1 fibrillinopathies are a family of connective tissue disorders of which Marfan syndrome is the most common, affecting between 2-3 in 10,000 individuals. Marfan syndrome is a multisystem disorder characterised by ocular, skeletal and cardiovascular abnormalities and can be caused by any one of over 2800 unique mutations reported across the fibrillin-1 (FBN1) gene. FBN1 encodes the large extracellular glycoprotein, fibrillin-1; the fibrillin-1 monomers aggregate to form the backbone of microfibrils. Fibrillin-1 has both structural and regulatory roles, including the regulation of transforming growth factor-beta. This regulation is critical in maintaining extracellular matrix stability and dysregulation of this function is one of the keystones of the Marfan syndrome pathogenesis. Mutations in FBN1 can result in reduced fibrillin-1 expression, loss-of-function or the production of two different fibrillin-1 proteins that are unable to interact to form functional microfibrils. The result in all three cases is a lack of functional microfibrils and destabilisation of the extracellular matrix. The current standard of care relies heavily on surgical intervention and lifelong use of medications to slow disease progression, thus the need for new therapeutic options that target the cause of disease. This thesis focused on developing a suite of short synthetic nucleic acid sequences, known as antisense oligonucleotides, to selectively manipulate FBN1 pre-mRNA splicing. We hypothesised that the removal of an amenable mutation-associated exon would result in one of the following scenarios. For missense mutations, removing the mutation-associated exon from affected and unaffected transcripts would eliminate the aberrant sequence and restore homogeneity between fibrillin-1 monomers. For splice-site and in-frame deletion mutations, excluding the mutation-associated exon from the remaining healthy transcripts would restore the domain periodicity and monomer homogeneity. Lastly, for mutations resulting in a premature termination codon, excluding the mutation-associated exon from the affected transcripts would restore the reading frame, rescuing transcript functionality. The mutation-associated exon would also need to be removed from the unaffected transcripts to maintain monomer homogeneity. For each of these scenarios, we hypothesised that the internally truncated proteins produced would be capable of forming functional microfibrils, thereby reducing the severity or slowing the progression of the Marfan syndrome phenotype. As an initial proof-of-concept for this project, antisense oligonucleotide sequences targeting FBN1 exon 52 were assessed. A promising sequence induced dose-dependent exon skipping in healthy control cells allowing us to observe the formation of healthy fibrillin-1 fibres with 0% exon skipping, loss of extruded fibrillin-1 fibres with 50% skipping; mimicking the disease-like state, and subsequent re-appearance of extracellular fibrillin-1 fibres with greater than 80% skipping indicating that the internally truncated fibrillin-1 monomers are capable of forming aggregates. Similarly, we demonstrate that FBN1 exons 47 and 59 can be efficiently excluded, and sufficient skipping can result in fibrillin-1 fibre formation. However, many of the FBN1 exons targeted were not as readily excised from the mature mRNA. Comparison of three antisense oligonucleotide chemistries revealed the promising efficacy of the newer thiophosphoramidate morpholino oligomer chemistry. Similar to the commonly used phosphorodiamidate morpholino oligomer, the thiophosphoramidate morpholino oligomer sequences resulted in efficient and consistent FBN1 exon 52 skipping. Both chemistries also had little effect on paraspeckle protein distribution, an indicator of toxicity, unlike the third, 2′OMe-PS, chemistry that caused gross paraspeckle protein disruption. Therefore, thiophosphoramidate morpholino oligomer should be included in the repertoire of chemistries routinely used in studies developing antisense therapeutics. Lastly, while we demonstrate that >80% exon skipping can lead to fibrillin-1 microfibril-like formations in vitro, we could not confirm the functionality of these fibres nor the effect of exon skipping on the Marfan syndrome phenotype. Nevertheless, this study demonstrates proof-of-concept and lays a solid foundation for further development of antisense oligonucleotides to treat the type-1 fibrillinopathies.
APA, Harvard, Vancouver, ISO, and other styles
34

Errington, Stephen J. "Target selection for antisense oligonucleotide induced exon skipping in the dystrophin gene." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2004. https://ro.ecu.edu.au/theses/794.

Full text
Abstract:
Duchene Muscular Dystrophy (DMD), and the milder allelic Becker muscular dystrophy (EMD), are X-linked recessive muscle wasting disorders characterised by mutations in the dystrophin gene. DMD occurs at a frequency of approximately 1 in 3500 male newborns and life expectancy is typically less than 30 years. Due to progressive muscle wasting, affected boys are restricted to a wheelchair by the age of 12 years. The most common cause of death is pneumonia, compounded by cardiac involvement. Mutations that disrupt the dystrophin reading frame, or prevent the synthesis of either terminus, preclude the synthesis of a fully functional dystrophin. The subsequent Joss of membrane integrity results in a severe DMD phenotype, as these weakened but still functional muscle fibres are subject to continuous cycles of damage and regeneration. Conversely, BMD mutations are generally found to be in-frame deletions where a shorter but semi-functional protein with intact amino and carboxyl tennini has been synthesised. BMD has an incidence almost ten times less than DMD. While the distribution of myopathy parallels DMD, the onset and progression of BMD is variable and generally less severe and some affected individuals are virtually asymptomatic.
APA, Harvard, Vancouver, ISO, and other styles
35

Gardner, S. J. "The synthesis of novel nucleoside analogues from nitroimidazoles." Thesis, Keele University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388875.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Ossipov, Dimitri. "Aspects of Antisense and Antigene Chemistry of Oligonucleotides Tethered to Intercalators." Doctoral thesis, Uppsala University, Department of Bioorganic Chemistry, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2220.

Full text
Abstract:

Synthetic and physicochemical studies on appropriately functionalized ODN-conjugates have been performed to evaluate their abilities to act as antisense agents against RNA or as intramolecular DNA cross-linking agents. Intercalating aromatic systems [phenazine (Pnz), dipyridophenazine (DPPZ)] and metallointercalators such as Ru2+(phen)2(DPPZ) and Ru2+(tpy)(DPPZ)L [where L = chemically or photochemically labile ligand, phen = phenanthroline, tpy = terpyridine], which are covalently tethered to the oligo-deoxynucleotides (ODNs), have been chosen for this purpose. The ODN-conjugates were typically prepared by automated solid phase synthesis using phosphoramidite building blocks, or on solid supports, both functionalized with the chromophore groups. The photosensitive metal complex, Ru2+(tpy)(DPPZ)(CH3CN), has been incorporated by post-synthetic coupling to the amino-linker modified ODNs via an amide bond. The intercalating ability of the tethered chromophores gave enhanced stability of the duplexes and triplexes formed with ODN-conjugates and their complementary targets: DNA, RNA, or double-stranded DNA. The conjugation of DPPZ chromophore to ODN (at 3', 5' or at the middle) led us to incorporate Ru2+(phen)2(DPPZ) through the DPPZ ligand, for the first time. The corresponding (Ru2+-ODN)•DNA duplexes showed dramatic stabilization (ΔTm = 19.4 – 22.0ºC). The CD and DNase I footprinting experiments suggest that the stabilization is owing to metallointercalation by threading of the Ru2+(phen)2 moiety through the ODN•DNA duplex core, thus "stapling" the two helical strands from the minor to major groove. On the other hand, Ru2+(tpy)(DPPZ)(CH3CN)-ODN conjugates represent a new class of oligonucleotides containing the photoactivatible Ru2+ complexes, which can successfully crosslink to the complementary strand. The mechanism of cross-linking upon photoirradiation of [Ru2+(tpy)(DPPZ)(CH3CN)-ODN]•DNA involves in situ conversion to the reactive [Ru2+(tpy)(DPPZ)(H2O)-ODN]•DNA which are subsequently cross-linked through the G residue of the complementary DNA strand. All starting materials and products have been purified by HPLC and/or by PAGE and subsequently characterized by MALDI-TOF as well as ESI mass spectroscopy. Terminal conjugation of the planar Pnz and DPPZ groups through the flexible linkers were also shown to improve thermal stability of the ODN•RNA hybrid duplexes without alteration of the initial AB-type global helical structure as revealed from CD experiments. As a result, RNase H mediated cleavage of the RNA strand in the intercalator-tethered ODN•RNA duplexes was more efficient compared to the natural counterpart. The RNase H cleavage pattern was also found to be dependent on the chemical nature of the chromophore. It appeared that introduction of a tether at the 3'-end of the ODN can be most easily tolerated by the enzyme regardless of the nature of the appending chromophore. The tethered DPPZ group has also been shown to chelate Cu2+ and Fe3+, like phenanthroline group, followed by the formation of redox-active metal complex which cleaves the complementary DNA strand in a sequence-specific manner. This shows that the choice of appropriate ligand is useful to (i) attain improved intercalation giving Tm enhancement, and (ii) sequence-specifically inactivate target RNA or DNA molecules using multiple modes of chemistry (RNase H mediated cleavage, free-radical, oxidative pathways or photocross-linkage).

APA, Harvard, Vancouver, ISO, and other styles
37

Fadzen, Colin MacLaine. "Peptide-mediated delivery of antisense oligonucleotides and chemotherapeutics across biological barriers." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118259.

Full text
Abstract:
Thesis: Ph. D. in Biological Chemistry, Massachusetts Institute of Technology, Department of Chemistry, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references.
Many nucleic acids, peptides, and small molecules struggle to become clinically viable therapeutics as a result of poor delivery. Biological barriers such as the plasma membrane and the blood-brain barrier (BBB) contribute to this challenge as they can limit the passage of macromolecules. Cell-penetrating peptides (CPPs) that interact with membranes can improve the uptake of macromolecules across biological barriers. Here we explore methods for the peptide-mediated delivery of antisense oligonucleotides (ASOs) and chemotherapeutics. First, we address the issue that the optimal peptide sequence for the delivery of a macromolecular cargo is often context-dependent and specific to that cargo. With one class of ASO, we develop a paradigm that combines systematic screening of known CPPs in a functional assay for ASO delivery with machine learning methods. Using our computational model, we identify five novel sequences that increase ASO activity at least three-fold. Next, we demonstrate that combining CPPs of different classes generates chimeric peptides with synergistic effects on ASO delivery. These chimeras improve ASO activity twenty-fold, which is greater than any literature-reported sequence. Then, we examine peptide cyclization with perfluoroaryl-cysteine SNAr chemistry to improve the stability and delivery of peptide-ASO conjugates. We extend our SNAr chemistry to the synthesis of arginine-rich bicyclic peptides, which are more stable to proteolysis than single cycles. Both perfluoroaryl cyclic and bicyclic arginine-rich peptides improve ASO activity fourteen-fold. Consequently, we demonstrate that peptide cyclization with perfluoroaryl-cysteine SNAr chemistry enhances the ability of peptides to cross the BBB. We prepare macrocyclic analogues of both a CPP and a therapeutic peptide. We show that a subset of the macrocycles cross the BBB in both a cellular spheroid model of the BBB, as well as after intravenous injection in mice. Finally, we conjugate a platinum (IV) prodrug of the chemotherapeutic cisplatin to a brain-penetrating perfluoroaryl macrocycle and show that the amount of platinum in the mouse brain is fifteen-fold greater than cisplatin after five hours. In summary, we explore strategies to improve the peptide-mediated delivery of ASOs and small molecule chemotherapeutics across biological barriers. In the future, we envision extending these approaches to other macromolecular cargos of therapeutic interest.
by Colin MacLaine Fadzen.
Ph. D. in Biological Chemistry
APA, Harvard, Vancouver, ISO, and other styles
38

Graham, Duncan. "The synthesis and study of chemically modified anti-HIV antisense oligonucleotides." Thesis, University of Edinburgh, 1996. http://hdl.handle.net/1842/12055.

Full text
Abstract:
It has been reported that the presence of a hydrophobic moiety at the 5-position of 2'-deoxyuridine increases duplex stability when incorporated into an oligonucleotide. A series of 2'-deoxyuridine analogues modified at the 5-position have been synthesised. The stability of a 12mer duplex containing these residues was analysed by ultraviolet melting studies. Of the groups tested 5-propynyl-2'-deoxyuridine imparted greatest stability on the duplex. Thermodynamic parameters show that the reason for increased stability arises from a decrease in enthalpy which is related to the base stacking process. Ultra high field NMR was used to elucidate the 3D structures of a deoxydodecanulceotide containing 5-propynyl-2'-deoxyuridine residues at two different positions. These structures show an increased π-π overlap with the base on the 5'-side of the modified base. This suggests the degree of stabilisation imparted by the propyne moiety may be sequence dependent. Cellular uptake of antisense oligonucleotides is particularly low. In an attempt to improve uptake a cholesterol moiety linked by two different lengths of alkyl spacer was attached to an antisense oligonucleotide. Anti-HIV activity of the cholesteryl conjugated oligonucleotide was improved relative to the unmodified oligonucleotide. Pharmacokinetic properties of the cholesteryl conjugated oligonucleotide was less than that of the unmodified oligonucleotide.
APA, Harvard, Vancouver, ISO, and other styles
39

Dysko, Anna Monika. "Synthesis and properties of oligonucleotides containing triazole backbone linkages and 2'-modifications for therapeutic applications." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:20fc1203-9751-4654-b497-5f4d97f874a1.

Full text
Abstract:
Antisense oligonucleotides are short strands of DNA, which bind to their complementary mRNA target to prevent protein translation. Although conceptually appealing, for their practical use as drugs, these oligonucleotides must have better cellular uptake, resistance to enzymatic degradation, and target selectivity. In this work, new synthetic chemistry is established to prepare a novel group of chemically modified oligonucleotides. The anionic phosphodiester backbone is partially replaced with a neutral triazole and, at the same time, the 2'-position of the ribose sugar is functionalised with pyrene, anthraquinone, or guanidine moieties. Being unnatural, the triazole backbone is inherently resistant to enzymatic degradation, while the reduced negative charge potentially improves cell penetration. The limitation of introduction of a triazole backbone into the antisense strand is its destabilising effect on the duplex formation with their complementary target. In this study, the 2'-modifications are used to restore the lost duplex stability and they have been found to be very efficient stabilising moieties. To evaluate the viability of this strategy, reporter gene assays based on splice-switching model are used. Promisingly, these modified oligonucleotides have successfully shown antisense splice-switching activity, suggesting there is further scope for their improvement.
APA, Harvard, Vancouver, ISO, and other styles
40

Wei, Xiaohui. "Pharmacokinetics, pharmacodynamics and metabolism of GTI-2040, a phosphorothioate oligonucleotide targeting R2 subunit of ribonucleotide reductase." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1143220921.

Full text
APA, Harvard, Vancouver, ISO, and other styles
41

Li, Qing. "Conformationally Constrained Oligonucleotides for RNA Targeting." Doctoral thesis, Uppsala universitet, Kemisk biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-179069.

Full text
Abstract:
A short oligonucleotide sequence as in a single-stranded antisense oligo nucleotides (AON) or in double-stranded small interfering RNAs (siRNA) can modulate the gene expression by targeting against the cellular mRNA, which can be potentially exploited for therapeutic purposes in the treatment of different diseases. In order to improve the efficacy of oligonucleotide-based drugs, the problem of target affinity, nuclease stability and delivery needs to be addressed. Chemical modifications of oligonucleotides have been proved to be an effective strategy to counter some of these problems. In this thesis, chemical synthesis of conformationally constrained nucleosides such as 7′-Me-carba-LNA-A, -G, -MeC and -T as well as 6′, 7′-substituted α-L-carba-LNA-T (Papers I-III) was achieved through a key free-radical cyclization. 1D and 2D NMR techniques were employed to prove the formation of bicyclic ring system by free-radical ring closure as well as to identify the specific constrained conformations in sugar moieties. These sugar-locked nucleosides were transformed to the corresponding phosphoramidites and incorporated into antisense oligonucleotides in different sequences, to evaluate their physicochemical and biochemical properties for potential antisense-based therapeutic application. AONs modified with 7′-Me-carba-LNA analogues exhibited higher RNA affinities (plus 1-4°C/modification) (Papers I & III), but AONs containing α-L-carba-LNA analogues showed decreased affinities (minus 2-3°C/ modification) (Paper II) towards complementary RNA compared to the native counterpart.  It has been demonstrated in Papers I-III that 7′-methyl substitution in α-L-carba-LNA caused the Tm drop due to a steric clash of the R-configured methyl group in the major groove of the duplex, whereas 7′-methyl group of carba-LNA locating in the minor groove of the duplex exerted no obviously negative effect on Tms, regardless of its orientation. Moreover, AONs containing 7′-Me-carba-LNA and α-L-carba-LNA derivatives were found to be nucleolytically more stable than native AONs, LNA modified AONs as well as α-L-LNA modified ones (Papers I-III). We also found in Paper II & III that the orientations of OH group in C6′ of α-L-carba-LNAs and methyl group in C7′ of 7′-Me-carba-LNAs can significantly influence the nuclease stabilities of modified AONs. It was proved that the methyl substitution in cLNAs which points towards the vicinal 3′-phosphate were more resistant to nuclease degradation than that caused by the methyl group pointing away from 3′-phosphate. Additionally, AONs modified with 7′-Me-carba-LNAs and α-L-carba-LNAs were found to elicit the RNase H mediated RNA degradation with comparable or higher rates (from 2-fold to 8-fold higher dependent upon the modification sites) as compared to the native counterpart. We also found that the cleavage patterns and rates by E. coli RNase H1 were highly dependent upon the modification sites in the AON sequences, regardless of the structural features of modifications (Papers II & III). Furthermore, we have shown that the modulations of Tms of AON/RNA duplexes are directly correlated with the aqueous solvation (Paper III).
APA, Harvard, Vancouver, ISO, and other styles
42

Xu, Jian, and 徐堅. "Using antisense oligonucleotide in whole embryo culture to study gene interactions during mouse gastrulation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31220150.

Full text
APA, Harvard, Vancouver, ISO, and other styles
43

Xu, Jian. "Using antisense oligonucleotide in whole embryo culture to study gene interactions during mouse gastrulation /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19918884.

Full text
APA, Harvard, Vancouver, ISO, and other styles
44

Almeida, Carina Marisa dos Santos. "Gold nanoparticle-DNA conjugates for oligonucleotide vectorization towards gene silencing." Master's thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6212.

Full text
Abstract:
Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina
The main objective of the work presented in this thesis was to develop a gene silencing system by taking advantage of the nanovectorization capability and optical properties of gold nanoparticles. The idea is based on the construction of a DNA structure containing a therapeutic oligonucleotide with the ability to form Hoogsteen hydrogen bonds with double-stranded DNA, producing a DNA triple helix, besides silencing the gene of interest. Hoogsteen bonds, more unstable than the conventional Watson-Crick bonds, permit the achievement of lower melting temperatures. This attribute, coupled with the ability to generate heat by laser irradiation of the gold nanoparticles used, will allow the release of the therapeutic oligonucleotide and subsequent gene silencing without significant increase in the medium’s temperature. Thus, the thesis comprises three major sections: structure design and formation, vectorization, and gene expression silencing; the tasks involved in each of these sections were conducted in parallel. The design of the obtained structure took into account the desired melting temperature, stability at physiological conditions of the sequence-forming nucleotides, the number of Hoogsteen bonds and ionic conditions. To evaluate the formation of this structure, spectroscopic techniques were mainly used: FRET analysis and ultraviolet melting curves. Both approaches allowed the identification of interactions in the presence of therapeutic oligonucleotide compared with its absence, which may indicate structure formation. In addition, melting curves allowed the determination of the temperature of release of this oligonucleotide – 40ºC. The double-stranded DNA functionalization to gold nanoparticles has been achieved, but there was no difference in electrophoretic migration when the three oligonucleotides were present. However, the therapeutic oligonucleotide was able to efficiently inhibit gene expression in in vitro transcription and translation assays with efficiency up to 95% and 60% respectively.
APA, Harvard, Vancouver, ISO, and other styles
45

Klimuk, Sandra K. "Liposome encapsulation enhances the anti-inflammatory activity of an ICAM-1 antisense oligonucleotide." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ46365.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
46

Varghese, Oommen P. "Conformationally Constrained Nucleosides : Design, Synthesis, and Biochemical Evaluation of Modified Antisense Oligonucleotides." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8266.

Full text
APA, Harvard, Vancouver, ISO, and other styles
47

Mejzini, Rita. "Development of antisense oligonucleotides with therapeutic potential for treating amyotrophic lateral sclerosis." Thesis, Mejzini, Rita (2022) Development of antisense oligonucleotides with therapeutic potential for treating amyotrophic lateral sclerosis. PhD thesis, Murdoch University, 2022. https://researchrepository.murdoch.edu.au/id/eprint/66499/.

Full text
Abstract:
Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease characterised by degenerative changes to both upper and lower motor neurons. Current treatment options for ALS are based on symptom management and respiratory support, with the only approved medications prolonging survival for just a few months. Over 60 clinical trials for drugs to treat ALS have ended in disappointment in the last decades, the majority of which were for small molecule-based treatments. Antisense oligonucleotides (AONs) are short nucleic acid analogues that can be designed to directly and specifically target the pathological hallmarks of disease at the RNA level. AONs can work via several mechanisms including strategies that rely on the endogenous RNase H enzymes to degrade target transcripts or strategies that involve the steric block of splicing factors or cellular machinery. Developments in AON based medicine in recent years has led to several new AON therapies receiving approvals to treat various conditions. The work outlined in this thesis has involved the development and assessment of AONs with therapeutic potential for treating ALS. AONs with the phosphorodiamidate morpholino oligomer (PMO) chemistry were preferred in this work due to their strong safety profile and clinical approvals for Duchenne muscular dystrophy. AONs that rely on RNase H require chemical modifications such as the phosphorothioate backbone (PS) modification to increase their stability and cellular uptake. PMOs are nucleic acid analogous that are inherently stable but are not compatible with RNase H activity, instead requiring a steric blocking strategy. ALS is a heterogenous disease, however a common feature is the cytoplasmic aggregation of proteins. The transactive response DNA-binding protein 43 (TDP-43) encoded by the TARDBP gene was identified in 2006 as a primary protein component of intracellular inclusions in most ALS cases, occurring in more than 90% of patients. As TDP-43 is autoregulated, its cytoplasmic mislocalisation in ALS leads to its upregulation. In this work, AONs with the PMO chemistry that utilise a splice-switching strategy were developed that can reduce the expression of TDP-43. It has recently been discovered that mislocalisation of TDP-43 leads to the downregulation of Stathmin-2, an important neuronal protein involved in axonal development and repair. AONs that can prevent the down-regulation of Stathmin-2 in response to TDP-43 nuclear depletion in human cells were also successfully developed. These AONs alone or in combination could have therapeutic potential to treat the majority of sporadic ALS patients. iii A subset of ALS patients, including some with early-onset ALS, have pathogenic variants in the FUS gene which leads to FUS protein mislocalisation and aggregation. There is also mounting evidence that FUS may play a role in the pathogenesis of sporadic ALS. Another focus of this study was the development of AONs that can modify expression of FUS. Two strategies were explored, including a splice switching strategy, to reduce total FUS expression. A steric blocking PMO AON was developed that can reduce FUS expression in human cells. As FUS-ALS is usually inherited in an autosomal dominant manner, a second strategy aimed to selectively knock down expression of only one FUS allele. This therapeutic strategy would allow expression of the normal allele in FUS-ALS patients, reducing potential complications due to insufficiency of the protein. Several AON design parameters and chemistries were explored with AONs using the newer thiophosphoramidate morpholino oligomer chemistry showing promise in achieving this aim. The work presented in this thesis has provided evidence that splice-switching AON based therapeutics that can reduce expression of TDP-43 while preventing the down-regulation of Stathmin-2 is feasible. Like-wise both splice-switching and RNase H utilising allele selective, FUS targeted AONs have been developed that have therapeutic potential in treating FUS-ALS. With further development, there is hope that this work may contribute to the availability of disease altering antisense based therapeutics for ALS patients.
APA, Harvard, Vancouver, ISO, and other styles
48

FARAVELLI, IRENE. "SPINAL MUSCULAR ATROPHY ORGANOIDS REVEAL DEVELOPMENTAL DEFECTS RESCUED BY ANTISENSE OLIGONUCLEOTIDES TREATMENT." Doctoral thesis, Università degli Studi di Milano, 2023. https://hdl.handle.net/2434/950656.

Full text
Abstract:
Spinal muscular atrophy (SMA) is a neuromuscular disease caused by mutations in the SMN1 gene. Recent therapies have significantly modified SMA natural course, but treatment efficacy remains variable and the reasons beyond this variability are still largely unexplored. Identifying pre-symptomatic SMA features is crucial to define the optimal therapeutic window and most efficient strategy in order to increase drug efficacy. Recent studies have shown that patients start to develop pathological signs in utero, suggesting that SMA retains an important, and still under investigated, developmental phenotype. In the present study, we generated SMA type 1 cerebral and spinal cord organoids (SCOs) to recapitulate human-specific early neurodevelopmental features. Single-cell transcriptomics revealed a pervasive transcriptional alteration in multiple cell populations, along with drastic changes in motor neuron gene expression. Morphological analyses detected early differentiation defects in SMA SCOs, unveiling a significant developmental component to the SMA pathology. Whole organoids electrophysiological acute recording revealed altered basal activity and pronounced hyperexcitability. Optimized peptide-conjugated antisense oligonucleotide tested in SMA SCOs successfully reverted both morphological and functional deficits. Of note, SMA cerebral organoids displayed similar functional deficits, revealing the widespread impact of the disease, beyond the spinal cord. Our findings provide proof of concept that SMA organoids can be used for effective drug testing, while demonstrating early-onset and pervasive features of SMA, which need to be considered in the therapeutic perspectives.
APA, Harvard, Vancouver, ISO, and other styles
49

Lehmann, Thomas. "Synthese, Eigenschaften und Anwendung Gallensäure derivatisierter Antisense-Oligonukleotide gegen Hepatitis-C-Virus RNA." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963895567.

Full text
APA, Harvard, Vancouver, ISO, and other styles
50

Schreckenberg, Rolf. "Regulationsmechanismen des alpha-adrenerg induzierten hypertrophen Wachstums ventrikulärer Herzmuskelzellen." Giessen : VVB Laufersweiler, 2006. http://geb.uni-giessen.de/geb/volltexte/2007/4435/index.html.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Oligonucleotidi antisenso' for other source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography