Gold Nanobeacons for Tracking Gene Silencing in Zebrafish

Abstract

The use of gold nanoparticles for effective gene silencing has demonstrated its potential as a tool for gene expression experiments and for the treatment of several diseases. Here, we used a gold nanobeacon designed to specifically silence the enhanced green fluorescence protein (EGFP) mRNA in embryos of a fli-EGFP transgenic zebrafish line, while simultaneously allowing the tracking and localization of the silencing events via the beacon’s emission. Fluorescence imaging measurements demonstrated a decrease of the EGFP emission with a concomitant increase in the fluorescence of the Au-nanobeacon. Furthermore, microinjection of the Au-nanobeacon led to a negligible difference in mortality and malformations in comparison to the free oligonucleotide, indicating that this system is a biocompatible platform for the administration of gene silencing moieties. Together, these data illustrate the potential of Au-nanobeacons as tools for in vivo zebrafish gene modulation with low toxicity which may be used towards any gene of interest.

The Potential of Zebrafish as a Model Organism for Improving the Translation of Genetic Anticancer Nanomedicines

“…Apart from the use of zebrafish for the development of novel cancer therapeutics, including nanotherapeutics, only a few studies have been reported using this model to test preclinical genetic nanomedicines [ 130 , 131 , 132 ]. The first study found in the literature evaluates a synergistic therapy based on the co-encapsulation of a pigment-epithelium-derived factor (PEDF) plasmid with paclitaxel, a small molecular chemotherapeutic drug, into poly(lactic-co-glycolic acid) (PLGA) nanoparticles, in a transgenic zebrafish model Flk-1:eGFP.…”

Gold Nanoparticles for BCR-ABL1 Gene Silencing: Improving Tyrosine Kinase Inhibitor Efficacy in Chronic Myeloid Leukemia

“…Gene silencing has profited from nanovectorization strategies that extend circulation half-life of therapeutic nucleic acids while improving cell uptake 25, 26. Here, we used AuNPs to deliver a specific oligo targeting the BCR-ABL1 mRNA sequence in CML cells, where the silencing moiety was in a stem-loop configuration to improve selectivity and specificity toward target sequence 22, 27. AuNPs with 14 nm in diameter were synthesized and further functionalized with polyethylene glycol (AuNP@PEG) and with a ssDNA targeting the BCR-ABL1 mRNA sequence (50 oligonucleotide density per nanoparticle).…”

“…Gold nanoparticles (AuNPs) protect the antisense oligonucleotide against degradation by RNases, thus increasing circulation half-life and, therefore, the payload of therapeutic agent that is delivered to cells. The potential of AuNPs to vectorize actuators for gene silencing via simple assembly onto the nanoparticle core has been demonstrated in vitro and in vivo for a range of different nucleic acid moieties, including small interfering RNA (siRNA)15, 16, 17, 18, 19 and antisense ssDNA 20, 21, 22, 23, 24. The latter has been proven to be very specific, particularly when using stem-looped oligonucleotides, making it suitable for the real-time monitoring of gene silencing via gold nanobeacons 20, 21, 22…”

Gene Therapy in Cancer Treatment: Why Go Nano?

“…Indeed, Vinhas and collaborators have demonstrated that AuNPs functionalized with an antisense oligonucleotide against BCR-ABL mRNA, a fusion mRNA that when translated gives rise to a constitutively active tyrosine kinase that plays a central role on leukemogenesis, induces an effective silencing and increase in K562 cell death [15]. Also, Cordeiro and collaborators demonstrated the applicability and efficiency of Au-nanobeacons for in vivo silencing of a fli-enhanced green fluorescence protein (fli-EGFP) transgenic zebrafish embryos [175].…”