scholarly journals Chimeric siRNAs with chemically modified pentofuranose and hexopyranose nucleotides: altritol-nucleotide (ANA) containing GalNAc–siRNA conjugates: in vitro and in vivo RNAi activity and resistance to 5′-exonuclease

2020 ◽  
Vol 48 (8) ◽  
pp. 4028-4040
Author(s):  
Pawan Kumar ◽  
Rohan Degaonkar ◽  
Dale C Guenther ◽  
Mikhail Abramov ◽  
Guy Schepers ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Small Interfering Rna ◽  
Antisense Strand ◽  
Seed Region ◽  
Chemically Modified ◽  
Interfering Rna ◽  
Insight Into ◽  
Rnai Activity

Abstract In this report, we investigated the hexopyranose chemical modification Altriol Nucleic Acid (ANA) within small interfering RNA (siRNA) duplexes that were otherwise fully modified with the 2′-deoxy-2′-fluoro and 2′-O-methyl pentofuranose chemical modifications. The siRNAs were designed to silence the transthyretin (Ttr) gene and were conjugated to a trivalent N-acetylgalactosamine (GalNAc) ligand for targeted delivery to hepatocytes. Sense and antisense strands of the parent duplex were synthesized with single ANA residues at each position on the strand, and the resulting siRNAs were evaluated for their ability to inhibit Ttr mRNA expression in vitro. Although ANA residues were detrimental at the 5′ end of the antisense strand, the siRNAs with ANA at position 6 or 7 in the seed region had activity comparable to the parent. The siRNA with ANA at position 7 in the seed region was active in a mouse model. An Oligonucleotide with ANA at the 5′ end was more stable in the presence of 5′-exonuclease than an oligonucleotide of the same sequence and chemical composition without the ANA modification. Modeling studies provide insight into the origins of regiospecific changes in potency of siRNAs and the increased protection against 5′-exonuclease degradation afforded by the ANA modification.

scholarly journals Natural Polysaccharides for siRNA Delivery: Nanocarriers Based on Chitosan, Hyaluronic Acid, and Their Derivatives

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2570 ◽  
Author(s):  
Inés Serrano-Sevilla ◽  
Álvaro Artiga ◽  
Scott G. Mitchell ◽  
Laura De Matteis ◽  
Jesús M. de la Fuente
Keyword(s):  
Drug Delivery ◽  
Hyaluronic Acid ◽  
Small Interfering Rna ◽  
Drug Delivery Systems ◽  
Sirna Delivery ◽  
Delivery Systems ◽  
Low Toxicity ◽  
Interfering Rna

Natural polysaccharides are frequently used in the design of drug delivery systems due to their biocompatibility, biodegradability, and low toxicity. Moreover, they are diverse in structure, size, and charge, and their chemical functional groups can be easily modified to match the needs of the final application and mode of administration. This review focuses on polysaccharidic nanocarriers based on chitosan and hyaluronic acid for small interfering RNA (siRNA) delivery, which are highly positively and negatively charged, respectively. The key properties, strengths, and drawbacks of each polysaccharide are discussed. In addition, their use as efficient nanodelivery systems for gene silencing applications is put into context using the most recent examples from the literature. The latest advances in this field illustrate effectively how chitosan and hyaluronic acid can be modified or associated with other molecules in order to overcome their limitations to produce optimized siRNA delivery systems with promising in vitro and in vivo results.

scholarly journals Switching the intracellular pathway and enhancing the therapeutic efficacy of small interfering RNA by auroliposome

2020 ◽  
Vol 6 (30) ◽  
pp. eaba5379 ◽  
Author(s):  
Md. Nazir Hossen ◽  
Lin Wang ◽  
Harisha R. Chinthalapally ◽  
Joe D. Robertson ◽  
Kar-Ming Fung ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Gold Nanoparticles ◽  
Gene Silencing ◽  
Small Interfering Rna ◽  
Sirna Delivery ◽  
Delivery Systems ◽  
Ovarian Cancer Cells ◽  
Interfering Rna

Gene silencing using small-interfering RNA (siRNA) is a viable therapeutic approach; however, the lack of effective delivery systems limits its clinical translation. Herein, we doped conventional siRNA-liposomal formulations with gold nanoparticles to create “auroliposomes,” which significantly enhanced gene silencing. We targeted MICU1, a novel glycolytic switch in ovarian cancer, and delivered MICU1-siRNA using three delivery systems—commercial transfection agents, conventional liposomes, and auroliposomes. Low-dose siRNA via transfection or conventional liposomes was ineffective for MICU1 silencing; however, in auroliposomes, the same dose gave >85% gene silencing. Efficacy was evident from both in vitro growth assays of ovarian cancer cells and in vivo tumor growth in human ovarian cell line—and patient-derived xenograft models. Incorporation of gold nanoparticles shifted intracellular uptake pathways such that liposomes avoided degradation within lysosomes. Auroliposomes were nontoxic to vital organs. Therefore, auroliposomes represent a novel siRNA delivery system with superior efficacy for multiple therapeutic applications.

scholarly journals Engineered Exosomes for the Targeted Delivery of a Novel Therapeutic Cargo to Enhance Sorafenib-Mediated Ferroptosis in Hepatocellular Carcinoma.

2021 ◽  
Author(s):  
Xiaoju Li ◽  
Qianqian Yu ◽  
Xinyan Guo ◽  
Chenlin Liu ◽  
Runze Zhao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Targeted Delivery ◽  
Rna Recognition Motif ◽  
Advanced Hepatocellular Carcinoma ◽  
Rna Recognition ◽  
Sorafenib Treatment ◽  
Recognition Motif ◽  
Interfering Rna

Abstract Background Sorafenib is one of the few effective first-line drugs approved for the treatment of advanced hepatocellular carcinoma (HCC). However, the development of drug resistance is common among individuals with HCC. Thus, there is an urgent need to solve this problem. Results Recent evidence indicated that the anticancer activity of sorafenib mainly relies on the induction of ferroptosis. In our study, genes that suppress ferroptosis, especially GPX4 and DHODH, were enriched in sorafenib-resistant cells and primary tissues and were associated with poor prognosis of HCC patients who received sorafenib treatment. Therefore, silencing GPX4 and DHODH might be a novel and effective strategy to overcome sorafenib resistance. Here, a novel ferroptosis inducer comprising a multiplex small interfering RNA (multi-siRNA) capable of simultaneously silencing GPX4 and DHODH was created. Then, exosomes with high multi-siRNA loading and HCC-specific targeting were established by fusing the SP94 peptide and the N-terminal RNA recognition motif (RRM) of U1-A with the exosomal membrane protein Lamp2b. The results from the in vitro and in vivo experiments indicate that this tumor-targeting nanodelivery system (ExoSP94−lamp2b−RRM-multi-siRNA) could enhance sorafenib-induced ferroptosis and overcome sorafenib resistance, which might open a new avenue for clinically overcoming sorafenib resistance. Conclusions We designed HCC-targeted exosomes (ExoSP94−Lamp2b−RRM) that can deliver a novel ferroptosis inducer. Our data show that ExoSP94−lamp2b−RRM-multi-siRNA could enhance sorafenib-induced ferroptosis by silencing GPX4 and DHODH expression and consequently increase HCC sensitivity to sorafenib. This is the first study to describe the use of engineered exosomes to overcome acquired sorafenib resistance with respect to ferroptosis.

scholarly journals Silencing of AURKA augments the antitumor efficacy of the AURKA inhibitor MLN8237 on neuroblastoma cells

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yan Yang ◽  
Lili Ding ◽  
Qi Zhou ◽  
Li Fen ◽  
Yuhua Cao ◽  
...  
Keyword(s):  
Small Interfering Rna ◽  
Neuroblastoma Cell ◽  
Neuroblastoma Cells ◽  
Inhibitory Effect ◽  
Neuroblastoma Cell Line ◽  
Inhibitory Effects ◽  
Rna Transfection ◽  
Interfering Rna

Abstract Background Aurora kinase A (AURKA) has been implicated in the regulation of cell cycle progression, mitosis and a key number of oncogenic signaling pathways in various malignancies including neuroblastoma. Small molecule inhibitors of AURKA have shown potential, but still not as good as expected effects in clinical trials. Little is known about this underlying mechanism. Here, we evaluated the inhibitory effects of AURKA inhibitor MLN8237 on neuroblastoma cells to understand the potential mechanisms responsible for tumor therapy. Methods MLN8237 treatment on neuroblastoma cell line IMR32 was done and in vivo inhibitory effects were investigated using tumor xenograft model. Cellular senescence was evaluated by senescence-associated β-gal Staining assay. Flow cytometry was used to tested cell cycle arrest and cell apoptosis. Senescence-associated signal pathways were detected by western blot. CD133 microbeads and microsphere formation were used to separate and enrich CD133+ cells. AURKA small interfering RNA transfection was carried to downregulate AURKA level. Finally, the combination of MLN8237 treatment with AURKA small interfering RNA transfection were adopted to evaluate the inhibitory effect on neuroblastoma cells. Results We demonstrate that MLN8237, an inhibitor of AURKA, induces the neuroblastoma cell line IMR32 into cellular senescence and G2/M cell phase arrest. Inactivation of AURKA results in MYCN destabilization and inhibits cell growth in vitro and in a mouse model. Although MLN8237 inhibits AURKA kinase activity, it has almost no inhibitory effect on the AURKA protein level. By contrast, MLN8237 treatment leads to abnormal high expression of AURKA in vitro and in vivo. Knockdown of AURKA reduces cell survival. The combination of MLN8237 with AURKA small interfering RNA results in more profound inhibitory effects on neuroblastoma cell growth. Moreover, MLN8237 treatment followed by AURKA siRNA forces senescent cells into apoptosis via suppression of the Akt/Stat3 pathway. Conclusions The effect of AURKA-targeted inhibition of tumor growth plays roles in both the inactivation of AURKA activity and the decrease in the AURKA protein expression level.

Cell-specific and targeted delivery of RNA moieties

2020 ◽  
Author(s):  
Aditi Bhargava ◽  
Peter Ohara ◽  
Luc Jasmin
Keyword(s):  
Nucleic Acids ◽  
Targeted Delivery ◽  
Immune Cell ◽  
Neuronal Cell ◽  
Cell Types ◽  
Specific Cell ◽  
Chemically Modified ◽  
Covalently Linked

AbstractDelivery of therapeutic moieties to specific cell types, such as neurons remains a challenge. Genes present in neurons are also expressed in non-neuronal cell types such as glia where they mediate non-targeted related functions. Thus, non-specific targeting of these proteins/channels has numerous unwanted side effects, as is the case with current small molecules or drug therapies. Current methodologies that use nanoparticles, lipid-mediated uptake, or mannitol in conjunction with lipids to deliver double-stranded RNA (dsRNA) have yielded mixed and unreliable results. We used a neuroanatomical tracer (B subunit of Cholera Toxin (CTB)) that binds to the ganglioside receptors (GM1) expressed on cells, including primary sensory neurons to deliver encapsulated dsRNA. This approach greatly improved delivery of dsRNA to the desired cells by enhancing uptake, reducing vehicle-mediated toxicity and protecting nucleotides from degradation by endonucleases. The delivery complex is internalized, and once inside the cell, the dsRNA naturally dissociates itself from the carrier complex and is very effective in knocking down cognate targets, both in vivo and in vitro. Past methods have used CTB-fusion proteins or chemically modified oligos or DNA moieties that have been covalently conjugated to CTB. Furthermore, CTB conjugated to an antigen, protein, or chemically modified nucleic acid is a potent activator of immune cell (T and B cells, macrophages) response, whereas CTB admixed with antigens or unmodified nucleic acids does not evoke this immune response. Importantly, in our method, the nucleic acids are not covalently linked to the carrier molecules. Thus, our method holds strong potential for targeted delivery of therapeutic moieties for cell types expressing GM1 receptors, including neuronal cell types.

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