Pinpointed Stimulation of EphA2 Receptors via DNA-Templated Oligovalence.

Christin Möser,Jessica Lorenz,Martin Sajfutdinow,David Smith

doi:10.3390/ijms19113482

Abstract

DNA nanostructures enable the attachment of functional molecules to nearly any unique location on their underlying structure. Due to their single-base-pair structural resolution, several ligands can be spatially arranged and closely controlled according to the geometry of their desired target, resulting in optimized binding and/or signaling interactions. Here, the efficacy of SWL, an ephrin-mimicking peptide that binds specifically to EphrinA2 (EphA2) receptors, increased by presenting up to three of these peptides on small DNA nanostructures in an oligovalent manner. Ephrin signaling pathways play crucial roles in tumor development and progression. Moreover, Eph receptors are potential targets in cancer diagnosis and treatment. Here, the quantitative impact of SWL valency on binding, phosphorylation (key player for activation) and phenotype regulation in EphA2-expressing prostate cancer cells was demonstrated. EphA2 phosphorylation was significantly increased by DNA trimers carrying three SWL peptides compared to monovalent SWL. In comparison to one of EphA2’s natural ligands ephrin-A1, which is known to bind promiscuously to multiple receptors, pinpointed targeting of EphA2 by oligovalent DNA-SWL constructs showed enhanced cell retraction. Overall, we show that DNA scaffolds can increase the potency of weak signaling peptides through oligovalent presentation and serve as potential tools for examination of complex signaling pathways.

Highlights

The field of structural DNA nanotechnology is based on using DNA as construction material for building nanometer-scale objects [1,2,3,4,5,6]
EphA2 expressing PC-3 cells were treated with different concentrations of DNA trimers carrying both a Cy3 dye and between 0–3 SWL peptides and were subsequently a2n
It was shown that even simple DNA nanostructures consisting of a few strands are limited to serving as functional carriers for bioactive peptides such as SWL but can enhance their activity and trigger specific downstream signaling pathways in a pinpointed manner

Summary

Introduction

The field of structural DNA nanotechnology is based on using DNA as construction material for building nanometer-scale objects [1,2,3,4,5,6]. In the case of double-stranded DNA, a single base pair corresponds to a 0.34 nm rise along the helical axis, facilitating a more precise spatial resolution for the placement of single molecules than is practically available through other means of top-down lithography or bottom-up molecular programming. This is relevant for interacting with and even controlling the behaviors of biological systems, since, by attaching several ligands to DNA objects, one can achieve optimized binding and activation of target structures such as proteins and receptors by matching their naturally defined distances between different binding or active sites. DNA nanostructures have been studied as platforms for therapeutic agents, anti-cancer compounds [8,9,10,11,12,13,14]

Methods

Results

Conclusion