Posters and guidelines
Guidelines for poster preparation
Please prepare your poster in A1 portrait format (59cm wide x 84cm long). Do not laminate your poster, or use heavy printing material. Further information about poster sizes can be found on the following link:
Posters larger than A1, or those in landscape orientation, will only be displayed subject to the availability of space.
Maximum capacity 15 A1 potrait posters
Please ensure you have appropriate permissions for the publication of your abstract from the original copyright holders. Should you wish your abstract not to be published, please notify us in writing at the time of abstract submission.
Posters will be displayed for the full duration of the symposium.
(Presenters in Bold)
If your abstract has been accepted for presentation but it does not appear in the list below, please let us know as soon as possible by email on Oligomer@LPMHealthcare.com.
Oligonucleotide bioengineering and vectorization to improve targeting of oncogenic transcription factors
Geoffrey Casas, Patrick Baril, Chantal Pichon, Patrick Midoux and Jean-Marc Malinge
Centre de Biophysique Moléculaire, CNRS, Orléans, France
DNA decoys that inhibit transcription factors involved in tumorigenesis are promising therapeutic oligonucleotides for cancer treatment. However, several limitations still remain to be overcome in order to improve their efficiency. The design of novel DNA oligonucleotides with higher bio-stability and multi-targeting capacity should potentiate cancer cell death and decrease drug resistance. Herein, we were interested in the improvement of two oncogenic transcription factors (TF) targeting, NF-κB and Stat3. We designed a circular DNA oligonucleotide with the aim to improve the decoy activity of standard linear DNA nucleic acids. Short double-stranded DNA minicircle (less than 250 base pairs) was generated by a new production method. The biostability of DNA minicircle in human serum is significantly increased as compared to linear oligonucleotide. As proof of concept, a minicircle of 95 base pairs in length containing two appropriate binding sequences for NF-κB was produced. It binds efficiently two NF-κB transcription factors in vitro and efficiently impairs cellular transcriptional activity of NF-κB. We also built decoy minicircle containing Stat3 transcription factor binding sites and determined its potential antitumor activity after delivery with histidinylated lipopolyplex. Stat3 minicircle exhibits anti-proliferative activity in several human and murine cancer cell lines in vitro with an efficacy significantly higher than standard anti-Stat3 linear DNA decoy. Concomitantly, Stat3 minicircle induces an expression decrease of the Stat3 target genes Cyclin D1 and Bcl-Xl in line with potential decoy activity of Stat3 minicircle. In vivo, using the orthotopic murine 4T1 breast cancer model, we observed that Stat3 minicircle induces reduction of tumor growth and lung metastases number. Our data indicate that DNA minicircle could be promising new type of decoy oligonucleotide. Further DNA minicircles design is in progress for dual NF-κB and Stat3 TFs targeting.
Investigating the cellular mechanisms controlling lipid nanoparticle mediated delivery of mRNA
Arpan Desai1, Samantha Peel2, Rebecca Lloyd2, Doug Ross-Thriepland2, James Pilling2 & Bev Isherwood2
1Advanced Drug Delivery, Pharmaceutical sciences, AstraZeneca, Darwin building 310, Cambridge Science Park, Milton road, CB4 0WG
2High Content Biology Group, Discovery Sciences, AstraZeneca, Darwin building 310, Cambridge Science Park, Milton road, CB4 0WG
Modified mRNAs hold potential to offer a pioneering way of treating disease by triggering the body’s natural processes for protein production. However, one major challenge is productive delivery of the modified mRNA to cell cytoplasm for protein translation. The use of lipid nanoparticle (LNP) based vehicles to aid delivery of nucleic acids is well documented, however key challenges remain with lack of efficacy observed in some target tissue types associated with poor uptake and endosomal entrapment. This work aims to unravel the key mechanisms controlling cellular uptake and intracellular trafficking of LNPs and mRNA cargo across different cell lines. We first screened uptake of LNPs and productive delivery of mRNA cargo across a range of tumour cell types. Cellular uptake and cytoplasmic delivery was monitored using fluorescently labelled LNPs delivering mRNAs encoding a reporter protein (eGFP). We found delivery to be highly variable, with some tumour types completely refractile to LNP based delivery. We then applied a phenotypic screening approach using selected libraries of small molecule compounds alongside RNA interference strategies with the objective to identify pathways that if perturbed would enhance LNP mediated delivery. This work has resulted in a greater understanding of the cellular mechanisms that control LNP based delivery and fate of mRNA cargo and will facilitate the design of next generation intracellular delivery technologies.
A new genetic alphabet: replacing four natural letters by non-canonical nucleobases for the propagation of the genetic information
Elena Eremeeva, Piet Herdewijn
Medicinal Chemistry, Rega Institute for Medicinal Research, KU Leuven, Herestraat 49, 1041, 3000 Leuven, Belgium
DNA and RNA are among the most remarkable biomolecules occurring in nature. They store and transfer all information using a universal genetic code composed of four letters: A, T, C & G. Here we posed as an intriguing question whether other than natural letters of the genetic alphabet can be used to build DNA & RNA to propagate information in vivo. These redesigned biomolecules with improved stability and chemical diversity could open new horizons in the development of advanced therapeutics (e.g., aptamers, ASO, plasmids, DNAzymes). Based on this premise, synthetic nucleic acids composed of non-canonical nucleotides (7-substituted-7-deaza-purines and 5-substituted pyrimidines) have been chosen as analogues of natural biopolymers. These fully-base modified systems, denoted DZA, are shown to be a versatile biomolecular tool: 1) They can form stable duplexes with ssDNA and ssDZA; 2) They can be used to produce diverse DZA libraries for aptamer selection; 3) Long partially (2 kb) or fully modified (1.5 kb) DZA fragments can be synthesized by PCR with natural DNA polymerases; 4) DZA segments can completely protect DNA from restriction enzyme cleavage; 5) DZA fragments can be accurately read by bacterial polymerases yielding to a functional protein (antibiotic resistance). Therefore, our study provides the first example of long fully base-modified DNA that is able to successfully replicate in vitro and serve as a genetic template in E.coli.
A synthetically designed siRNA targeting a new AGO2 splice variant reduces the tumorigenic properties of malignant melanoma cells
Lisa Linck and Anja Katrin Bosserhoff
Friedrich-Alexander University Erlangen-Nürnberg, Institute of Biochemistry, Fahrstraße 17, 91054 Erlangen, Germany (Prof Dr Bosserhoff is the Chair of Biochemistry and Molecular Medicine)
Malignant melanoma is among the top ten of the most frequent solid types of tumors. Due to its high rate of metastasis it contributes to 90% of all deaths caused by skin cancer. During melanoma progression the mechanism of RNA-interference (RNAi) plays an important role. RNAi can regulate the expression of various tumor associated genes on a post-transcriptional level via small non-coding RNAs (miRNAs or siRNAs) associated to one of four human Argonaute (AGO) proteins. We designed an siRNA targeting a yet unknown splice variant of the protein AGO2. Expression of this variant results in a protein lacking the first 77 N-terminal amino acids. Transfection of different melanoma cell lines with the siRNA induced a dramatic decrease in proliferation accompanied with a change of the cell morphology to a more planar phenotype. Interestingly, a late induction of apoptosis could be seen, but we neither observed an induction of senescence nor alterations in the cell cycle phases. Furthermore, the ability of the tumor cells to grow in single cell-derived colonies was reduced. Importantly, transfection of the siRNA had no influence on the expression of the normal AGO2 protein or mRNA. The observed phenotype is similar to a former described effect of small RNAs targeting promoter sequences and enhancing tumor suppressor gene expression. This RNA mediated activation (RNAa) is solely AGO2 dependent. It seems reasonable that the N-terminal region is important for this effect, because it differentiates AGO2 from its family members. We therefore postulate that the AGO2 variant lacking the N-terminus has an inhibitory effect on RNAa. This inhibition may cause a survival benefit of the cells by repression of tumor suppressor genes. Therefore, treatment with the specific siRNA provides a promising therapeutic tool to lower tumorigenic properties of malignant melanoma cells.
Optimization of the Rolling Circle Amplification as a method to detect strand invasion of Oligonucleotides into dsDNA
Tea Umek1, Negin Mozafari1, Rula Zain1,2, C.I. Edvard Smith1
1Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Karolinska University Hospital Huddinge, SE-141 86 Stockholm, Sweden.
2Department of Clinical Genetics, Centre for Rare diseases, Karolinska University Hospital, SE-171 76, Stockholm, Sweden.
Oligonucleotide based gene therapies have the potential to modulate both mRNA and DNA and are as such classified as antisense or anti-gene. Anti-gene oligonucleotides bind to and/or strand invade into dsDNA. The scope of this study was to develop a well optimized method for detection of strand invasion by a specific oligonucleotide, more specifically clamp-type bis Locked Nucleic Acid (bisLNA) oligomers, which bind to one strand via combined Watson & Crick and Hogsteen base pairing. This exposes the other strand on which Rolling circle amplification (RCA) can be executed. The method allows assessment of specific and off-target effects and complements the data on expression changes of the targeted gene, obtained from RT-PCR or Western blot. It is an isothermal enzymatic process where a linear padlock probe is first hybridized to the target, circularized by ligation and lastly amplified by DNA polymerase, forming a long stretch of single stranded DNA composed of thousands of tandem repeats complementary to the template. Visualization is carried out by the hybridization of fluorescently labelled oligonucleotides. Due to the closed nature of the D-Loop created upon bisLNA invasion the polymerization is restricted. To allow efficient rolling, a mismatch introducing probe and MutY DNA Glycosylase and EndonucleaseIV target cleaving step were introduced prior to amplification. Here we demonstrate that the method is successful on single stranded blocked oligonucleotide. However, further optimization in vitro on plasmid and in situ on plasmid transfected cells is under progress.