Poster abstracts

Poster number 72 submitted by Lindsey Fong

Chemical circularization of siRNAs

Lindsey Fong (Department of Biological Sciences, Carnegie Mellon University), Eduardo Paredes, Sourav Dey (Department of Chemical Sciences, Carnegie Mellon University), Subha Das (Department of Chemical Sciences, Carnegie Mellon University; Center for Nucleic Acids Science and Technology)

Abstract:
Small interfering RNAs (siRNAs) are double stranded RNAs that can target complementary mRNAs for degradation through the RNA interference (RNAi) pathway. Recently it was shown that circularization of the free ends of the siRNAs increase the stability and therapeutic window of RNAi knockdown, though improvements in approaches and yields of circularization are still desirable. We show that the copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction is an efficient and straightforward method of creating synthetic dumbbell shaped siRNAs with click-circularized ends, for effective and stable knockdown in S2 cells. We are also exploring obtaining the dumbbell shaped circularized RNAs through transcription, using a 5'-deoxy-5'hydrazinylguanosine (hydrazine) initiator to functionalize the 5'-terminus. A periodate reaction to render the 3'-end reactive to the 5'-terminus will close the loop and circularize the RNA. These methods provide alternate and efficient approaches to circularized siRNAs.

Keywords: siRNA, Click ligation