Brief communication: stability and catalytic activity of novel circular DNAzymes

DNAzymes: Expanding the Potential of Nucleic Acid Therapeutics

Nucleic acids drugs have been proven in the clinic as a powerful modality to treat inherited and acquired diseases. However, key challenges including drug stability, renal clearance, cellular uptake, and movement across biological barriers (foremost the blood-brain barrier) limit the translation and clinical efficacy of nucleic acid-based therapies, both systemically and in the central nervous system. In this study we provide an overview of an emerging class of nucleic acid therapeutic, called DNAzymes. In particular, we review the use of chemical modifications and carrier molecules for the stabilization and/or delivery of DNAzymes in cell and animal models. Although this review focuses on DNAzymes, the strategies described are broadly applicable to most nucleic acid technologies. This review should serve as a general guide for selecting chemical modifications to improve the therapeutic performance of DNAzymes.

Multiplex PCR to assay the effect of nucleic acid-based inhibitors on prothrombin transcript level

We compared an antisense-oligodeoxynucleotide and four DNAzymes directed to the prothrombin mRNA for their efficiency to reduce prothrombin transcript level in HepG2 cells. The DNAzymes have different binding arm symmetry and cleavage sites, but are directed to the identical target site of the antisense-oligodeoxynucleotide. The nucleic acid-based inhibitors were transfected into HepG2 cells and prothrombin transcript level was quantified and normalized to the beta-actin transcript level by multiplex PCR. All nucleic acid-based inhibitors reduced prothrombin transcript level and the effect was in almost all cases, strongest 24 h after transfection, but still remarkable up to 68 h after transfection. The antisense-oligodeoxynucleotide was more effective than the DNAzymes tested.