Poster abstracts
Poster number 114 submitted by Ashwani Sharma
RNA nanoparticle for specific EpCAM targeting and cancer cell delivery
Ashwani Sharma, Fengmei Pi, Dan Shu (Nanotechnology Center, Department of Pharmaceutical Science, College of Pharmacy, University of Kentucky, Lexington, KY 40536), Piotr Rychahou, B. Mark Evers (Markey Cancer Center, University of Kentucky, Lexington, KY 40536), Peixuan Guo (Nanotechnology Center, Markey Cancer Center, Department of Pharmaceutical Science, College of Pharmacy, University of Kentucky, Lexington, KY 40536)
Abstract:
The epithelial cell adhesion molecule (EpCAM) is a transmembrane protein overexpressed in epithelial cancers. High levels of EpCAM expression has been observed in 97.7% of colon, 90.7% of gastric, 87.2% of prostate cancers and in 63.9% of lung cancers, and has been used as a therapeutic target in cancer therapy. Several targeting ligands have been developed against EpCAM in recent past, but they suffer from limited sensitivity and lack of proficient clinical response. In this study, utilizing state-of-art RNA nanotechnology platform, we generated a serum and thermodynamically stable RNA aptamer against EpCAM from a 2’-Fluoro RNA library. The magnetic bead based SELEX was utilized to select and recover bound RNA sequences using EpCAM protein as target. After several rounds of selection, the library was cloned and sequenced. The selected aptamer was checked for its binding affinity to EpCAM by flow cytometry to colon and breast cancer cells, and was further validated by confocal fluorescence microscopy. The binding constant for the aptamer was calculated to be lower than 55 nM to different human cancer cells. To our knowledge, this is the first RNA aptamer selected utilizing RNA nanotechnology approach that can be used directly for targeted drug delivery. This novel 2’F RNA aptamer against EpCAM was further utilized for specific delivery of RNA interference therapeutics by conjugating siRNA or miRNA to the RNA aptamer.
References:
(1) Guo P. 2010. The Emerging Field of RNA Nanotechnology. Nature Nanotechnology, 5:833-842.
(2) Shu D, Shu Y, Haque F, Abdelmawla S and Guo P. 2011. Thermodynamically stable RNA three-way junction for constructing multifunctional nanoparticles for delivery of therapeutics. Nature Nanotechnology. 6:658-67.
(3) Haque F, Shu D, Shu Y, Shlyakhtenko L, Rychahou P, Evers M, Guo P. 2012 Ultrastable synergistic tetravalent RNA nanoparticles for targeting to cancers. Nano Today.7:245–57.
Keywords: RNA Nanotechnology, Aptamer, EpCAM protein