Polymer Nanoparticle-Mediated Delivery of MicroRNA Inhibition and Alternative Splicing

Abstract

The crux of current RNA-based therapeutics relies on association of synthetic nucleic acids with cellular RNA targets. Antisense oligonucleotide binding to mature microRNA and splicing junctions on pre-mRNA represent methods of gene therapy that respectively inhibit microRNA-mediated gene regulation and induce alternative splicing. We have developed biodegradable polymer nanoparticles--which are coated with cell-penetrating peptides--that can effectively deliver chemically-modified oligonucleotide analogs to achieve these forms of gene regulation. We found that this nanoparticle system could block the activity of the oncogenic microRNA, miR-155, as well as modulate splicing to attenuate the expression of the proto-oncogene, MCL-1. Regulation of these genes in human cancer cells reduced cell viability and produced pro-apoptotic effects. These findings establish polymer nanoparticles as delivery vectors for non-conventional forms of gene therapy activated by cellular delivery of RNA-targeted molecules, which have strong therapeutic implications.

MicroRNAs in Prostate Cancer: Small RNAs with Big Roles

“…Another challenge in utilizing miRNAs as novel drug targets for PCa is developing antagonist and delivery system with high efficiency and specificity. Various types of chemically modified anti-miRs have been utilized to repress miRNAs, such as locked nucleic acid oligonucleotides (LNAs), polylysine-conjugated peptide nucleic acids (PNAs) and phosphorodiamidate morpholino oligomers (PMOs) [109][110][111][112]. However, because the cellular internalization of these hydrophobic, large anti-miRs is often ineffective, a more efficient delivery system needs to be developed.…”

“…However, because the cellular internalization of these hydrophobic, large anti-miRs is often ineffective, a more efficient delivery system needs to be developed. Some attempts have been made to enhance the cellular uptake of anti-miRs by conjugating the antisense oligonucleotides with cellpenetrating peptides (CPPs), such as Tat, Ant, MPG and more recently, Polymer nanoparticles (NPs) [109,113,114].…”

Insights on chiral, backbone modified peptide nucleic acids: Properties and biological activity

“…53 All the AMOs described until now were based on the modification on the ribose or nucleic acid backbone but other non natural nucleic acid analog such as phosphorodiamidate morpholino oligonucleotide (PMO) 54 and peptide nucleic acid can be employed to inhibit miRNAs. 14,[55][56][57][58] PNAs constitutes good alternative as they have high stability to both chemical and enzymatic degradation. 10 PNAs form very stable PNA:RNA duplexes, which can efficiently disrupt the dsRNA duplex.…”

“…Saltzman et al reported the use of (PLGA) polymer nanoparticles (100-200nm) coated with a nona-arginine (R9) cell penetrating peptide to deliver neutral anti-miRNAs (PNA and PMO) to inhibit miRNA-155. 57 The inhibition of miRNA-155 was monitored by a dual luciferase reporter system in which the target binding sequence for miRNA-155 was introduced at 3 0 UTR of Renilla Luciferase. KB cells transfected with this sensor system showed the inhibition of miRNA-155 transfected by anti-miRNA PNA and PMO.…”

“…KB cells transfected with this sensor system showed the inhibition of miRNA-155 transfected by anti-miRNA PNA and PMO. 57 Babar et al 58 employed PLGA nanoparticles coated with penetratin (ANTP-NP), a different CPP. The delivery of antisense peptide nucleic acids encapsulated in ANTP-NP inhibited miRNA-155 and slowed the growth of pre-B-cell tumors in vivo, demonstrating these constructs as promising therapeutics for lymphoma/and leukemia.…”