Posters and guidelines
Thank you for considering to present your work as a poster at Oligo 2020 Oxford Virtual.
Digital poster submission deadline: Prepare your poster as you would normally do for printing, and submit your final poster as both PDF and JPG/PNG files via the link below no later than 26th March 2021. Late posters may not be included in the conference programme. Please DO NOT send your poster files by email.
Naming your poster files: Name your poster files as follows: <your surname>-RNAi21V-Poster.pdf | <your surname>-RNAi21V-Poster.png | <your surname>-RNAi21V-Poster.jpg, etc. For example, for David Jones, name your file as Jones-RNAi21V-Poster.pdf. DO NOT name your poster files as, e.g., Oxford-poster, poster2021v, Oxford-RNAi-poster. Such files will be automatically rejected.
Poster presentation: Posters will be made available via a secure page to the symposium participants before the meeting. There will be two ways to interact with the poster presenters:
- the participants will be able to ask questions via the Zoom chatbox during the mid-conference break ; and/or
- the participants can post their questions on Twitter at any time using the meeting hashtag #RNAiOx21V, as well as the poster specific hashtag (given under each poster abstract) – do tag @RNAiOxford and @LPMHealthcare in your tweets.
The poster presenters should regularly check Twitter for any questions about their posters before, during and after the meeting, and post their answers on Twitter using appropriate hashtags, as above.
Any further information about the poster presentations at this digital meeting will be available in the future.
Before uploading your poster, you must make sure that you follow ALL of the instructions above!
(Presenters in Bold)
Accepted poster abstracts (Unedited) will be published below. 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 emailing RNAiOxford@gmail.com.
Non-targeting control for MISSION shRNA library leads to SNRPD3 transcript downregulation and inhibition of cell proliferation
Hashtags: #RNAiOx21V, #MCzarnek
Maria Czarnek, Katarzyna Sarad, Agnieszka Karaś, Joanna Bereta
Department of Cell Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7 Street, 30-387 Kraków, Poland
For many years gene silencing by shRNA has been the method of choice for studying gene function in mammalian cells due to its potency and simplicity. The creation of RNAi libraries has enabled the development of high-throughput loss-of-function screens. One of the most widely used shRNA libraries is the lentiviral TRC library, commercially available through Merck as MISSION shRNA library. It contains shRNAs targeting around 15 thousand human and 15 thousand mouse transcripts. Each experiment involving the use of RNAi requires a so called “non-targeting” shRNA estimate possible unspecific effects of any shRNAs, including gene-targeting ones. MISSION library provides two non-targeting shRNA controls: SHC002, which is designed not to target any mammalian gene, and SHC016, which according to the supplier does not target any known genes from any species. We have found that one of these controls, SHC016, is cytotoxic to human and mouse cell lines. We generated vectors with tet-inducible expression of both control shRNAs. Using five human cell lines (A549, U251, HeLa, PC3 and MCF7) we proved that the expression of SHC016 induces growth arrest, albeit the underlying mechanism of this phenomenon differs between cell lines. We identified four transcripts that are downregulated by SHC016 and might affect cell viability: VPS4A, VPS4B, ARPP19 and SNRPD3. We proved that CRISPRi knockdown of one of those genes, SNRPD3, mimics the effects of SHC016 expression. Although off-target activity of shRNAs is widely recognized, most researchers focus on off-targets of gene-specific- rather than control shRNAs. The results of our work adds a new premise to the discussion about the sources of uncertainty of RNAi results.
Tyrosine-modified PEI for highly efficacious and biocompatible siRNA delivery in vitro, ex vivo and in vivo
Hashtags: #RNAiOx21V, #MKarimov
Michael Karimov, Alexander Ewe, Achim Aigner
Rudolf-Boehm-Institute for Pharmacology and Toxicology (Clinical Pharmacology), University of Leipzig, Medical Faculty, Härtelstraße 16-18, 04107 Leipzig, Germany
The delivery of small interfering RNAs (siRNA) is a promising approach for the target-specific knockdown of pathologically overexpressed genes. A major challenge is the safe and efficient delivery of siRNAs esp. for in vivo applications. The cationic polymer polyethylenimine (PEI) is a promising delivery system. However, while their high charge densities efficiently complex and protect the payload, PEIs are also associated with high cytotoxicity, colloidal aggregation and often moderate transfection efficacy. Chemical modifications are a promising strategy for further improvement.We developed a set of novel tyrosine-modified PEIs. These were thoroughly studied for optimal siRNA complexation conditions and other physicochemical properties. The biological and toxicological behaviour of the siRNA complexes was characterized in vitro. Finally, the most promising complexes were further evaluated ex vivo and in vivo. Gene silencing efficacies up to >90% were found in different cell lines and not associated with appreciable cytotoxicity. Incubation in the presence of serum, freezing or lyophilisation of nanoparticles indicated excellent colloidal and biophysical stability. In ex vivo studies based on a tumor tissue slice model, a profound knockdown of GAPDH was found on mRNA and protein levels. In a pre-clinical in vivo study in colon carcinoma xenograft-bearing mice, tyrosine-PEI/siRNA nanoparticles targeting the anti-apoptotic oncogenes survivin and PLK-1 showed strong tumor-inhibitory effects and knockdown of the target proteins by ~50% without adverse effects.In conclusion, the chemical modification of PEI with the amino acid L-tyrosine strongly improved the physicochemical stability, reduced the toxicity and increased the bioactivity of nanoparticles. Thus, we present tyrosine-modified PEIs as particularly efficient and biocompatible platform for siRNA delivery, as demonstrated in vitro, ex vivo and in different tumor models in vivo.
Analysis of polyethylenimine (PEI)-based polyplexes and lipopolyplexes for pulmonary siRNA delivery in 2D- and air-liquid interface culture
Hashtags: #RNAiOx21V, #SNoske
Sandra Noske, Alexander Ewe, Achim Aigner
Rudolf-Boehm-Institute for Pharmacology and Toxicology, Clinical Pharmacology, University of Leipzig, Germany
RNA interference (RNAi) is a highly conserved tool for gene regulation in eukaryotic organisms. It is based on the action of small interfering RNAs (siRNAs) on a target mRNA, which is cleaved and thus degraded. The downregulation of specific gene products offers new perspectives in the treatment of diseases like cancer, viral infections or genetic disorders. Due to its large surface and high vascularization, the lung is an attractive target organ for local and/or systemic application of siRNAs. A major bottleneck, however, is the delivery of active siRNA molecules to their target site. Hence, considerable research efforts have focused on the development and refinement of carriers, for overcoming extracellular and intracellular barriers. Polymeric nanoparticles, especially PEI-based ones, and their lipopolyplexes provide a promising system for gene delivery regarding to efficacy and the absence of unspecific cytotoxicity. By measuring gene knockdown, transfection efficacies were evaluated in lung cancer cell lines in 2D-cell culture and in an air-liquid interface culture system. Biological activities of nebulized (lipo)polyplexes were comparable to their non-nebulized counterparts. The ionic strength of the complexation buffer was decisive for particle size, and the positive ζ-potential of polyplexes was shielded upon lipopolyplex formation. Transfection efficacy was also observed in the air-liquid interface culture, as determined by fluorescent siRNA uptake and by reporter gene knockdown. In 2D culture, we have identified (lipo)polyplexes with high transfection efficacies and sufficient biocompatibility, even after nebulization. First results also indicate their biological activity in a more complex air-liquid interface system, but this may be affected by their interaction with pulmonary mucus. Taken together, this provides the basis for their prospective exploration as pharmacological carriers, aiming at the pulmonary application of siRNA for therapeutic use.
