Antigen-Specific Delivery of siRNA Against Eucaryotic Elongation Factor 2 by Rationally Designed Bivalent Aptamer-siRNA Transcripts
Poster Aug 17, 2007
nga Neef, Ulrich Wüllner, Andreas Eller, Michael Kleines, Rainer Fischer, Mehmet Kemal Tur and Stefan Barth
For potential therapeutic applications of RNA interference, new strategies for cell type specific delivery have to be developed. Aptamers selectively binding to e.g. tumor-associated antigens can be used to deliver siRNAs to antigen-positive tumor cells.
We used an aptamer that binds specifically to PSMA, a cell surface glycoprotein found in abundance on prostate cancer cells, and joined its 3’ end to a siRNA specific for Eukaryotic Elongation Factor 2 (EEF2).
This is an attractive target for cancer therapy because inhibiting EEF2 causes the rapid arrest of protein synthesis, inducing apoptosis and leading ultimately to cell death.
In order to enhance the therapeutic efficacy of the aptamer-siRNA, we increased the valency of the construct by rational design. Two anti-PSMA aptamers were designed such that each binding sequence could fold independently into its active conformation.
Here we show specific cytotoxicity resulting from siRNA-induced silencing of EEF2, as well as specific delivery to PSMA-expressing prostate cancer cells. Increasing the valency of the aptamer resulted in enhanced cytotoxicity compared with the monovalent constructs. The results presented here demonstrate the usefulness of multivalent aptamer-based delivery vehicles for siRNA therapeutics.
Despite the developments in conventional PCR, the complexity of multiplex Real Time PCR is still limited due to the lack of sufficient detection channels. To achieve high-end multiplexing capacity on standard Real Time PCR machines, Anapa Biotech has developed the MeltPlex® technology (see box on right).READ MORE
Genome-wide association studies (GWAS) have identified more than 100 genetic loci associated with type 2 diabetes. The majority of these are located in the intergenic or intragenic regions suggesting that the implicated variants may alter chromatin conformation. This, in turn, is likely to influence the expression of nearby or more remotely located genes to alter beta cell function. At present, however, detailed molecular and functional analyses are still lacking for most of these variants. We recently analysed one of these loci and mapped five causal variants in an islet-specific enhancer cluster within the STARD10 gene locus. Here, we aimed to understand how these causal variants influence b-cell function by alteration of the chromatin structure of enhancer clusterREAD MORE
Early life stress (ELS) is highly associated with development of psychopathology
and mood disorders in adulthood. Genetic studies have identified variation in the gene calcium voltage-gated channel subunit alpha1C (CACNA1C) to increase risk for several psychiatric disorders. This poster assessed the expression of Cacna1c following prepubertal stress.